From 419d5d38ac5d79dfd899522274c872854cfe17ac Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Mon, 5 Jun 2023 11:06:58 +0000 Subject: riscv: Rename __switch_to_aux() -> fpu The name of __switch_to_aux() is not clear and rename it with the determine function: __switch_to_fpu(). Next we could add other regs' switch. Signed-off-by: Guo Ren Signed-off-by: Guo Ren Signed-off-by: Greentime Hu Reviewed-by: Anup Patel Reviewed-by: Palmer Dabbelt Signed-off-by: Andy Chiu Tested-by: Heiko Stuebner Reviewed-by: Heiko Stuebner Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230605110724.21391-2-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/switch_to.h | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h index 60f8ca01d36e..4b96b13dee27 100644 --- a/arch/riscv/include/asm/switch_to.h +++ b/arch/riscv/include/asm/switch_to.h @@ -46,7 +46,7 @@ static inline void fstate_restore(struct task_struct *task, } } -static inline void __switch_to_aux(struct task_struct *prev, +static inline void __switch_to_fpu(struct task_struct *prev, struct task_struct *next) { struct pt_regs *regs; @@ -66,7 +66,7 @@ static __always_inline bool has_fpu(void) static __always_inline bool has_fpu(void) { return false; } #define fstate_save(task, regs) do { } while (0) #define fstate_restore(task, regs) do { } while (0) -#define __switch_to_aux(__prev, __next) do { } while (0) +#define __switch_to_fpu(__prev, __next) do { } while (0) #endif extern struct task_struct *__switch_to(struct task_struct *, @@ -77,7 +77,7 @@ do { \ struct task_struct *__prev = (prev); \ struct task_struct *__next = (next); \ if (has_fpu()) \ - __switch_to_aux(__prev, __next); \ + __switch_to_fpu(__prev, __next); \ ((last) = __switch_to(__prev, __next)); \ } while (0) -- cgit v1.2.3 From dc6667a4e7e36f283bcd0264a0be55adae4d6f86 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Mon, 5 Jun 2023 11:06:59 +0000 Subject: riscv: Extending cpufeature.c to detect V-extension Add V-extension into riscv_isa_ext_keys array and detect it with isa string parsing. Signed-off-by: Guo Ren Signed-off-by: Guo Ren Signed-off-by: Greentime Hu Suggested-by: Vineet Gupta Co-developed-by: Andy Chiu Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Reviewed-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20230605110724.21391-3-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/hwcap.h | 1 + arch/riscv/include/asm/vector.h | 26 ++++++++++++++++++++++++++ arch/riscv/include/uapi/asm/hwcap.h | 1 + arch/riscv/kernel/cpufeature.c | 11 +++++++++++ 4 files changed, 39 insertions(+) create mode 100644 arch/riscv/include/asm/vector.h (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index e0c40a4c63d5..574385930ba7 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -22,6 +22,7 @@ #define RISCV_ISA_EXT_m ('m' - 'a') #define RISCV_ISA_EXT_s ('s' - 'a') #define RISCV_ISA_EXT_u ('u' - 'a') +#define RISCV_ISA_EXT_v ('v' - 'a') /* * These macros represent the logical IDs of each multi-letter RISC-V ISA diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h new file mode 100644 index 000000000000..bdbb05b70151 --- /dev/null +++ b/arch/riscv/include/asm/vector.h @@ -0,0 +1,26 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright (C) 2020 SiFive + */ + +#ifndef __ASM_RISCV_VECTOR_H +#define __ASM_RISCV_VECTOR_H + +#include + +#ifdef CONFIG_RISCV_ISA_V + +#include + +static __always_inline bool has_vector(void) +{ + return riscv_has_extension_unlikely(RISCV_ISA_EXT_v); +} + +#else /* ! CONFIG_RISCV_ISA_V */ + +static __always_inline bool has_vector(void) { return false; } + +#endif /* CONFIG_RISCV_ISA_V */ + +#endif /* ! __ASM_RISCV_VECTOR_H */ diff --git a/arch/riscv/include/uapi/asm/hwcap.h b/arch/riscv/include/uapi/asm/hwcap.h index 46dc3f5ee99f..c52bb7bbbabe 100644 --- a/arch/riscv/include/uapi/asm/hwcap.h +++ b/arch/riscv/include/uapi/asm/hwcap.h @@ -21,5 +21,6 @@ #define COMPAT_HWCAP_ISA_F (1 << ('F' - 'A')) #define COMPAT_HWCAP_ISA_D (1 << ('D' - 'A')) #define COMPAT_HWCAP_ISA_C (1 << ('C' - 'A')) +#define COMPAT_HWCAP_ISA_V (1 << ('V' - 'A')) #endif /* _UAPI_ASM_RISCV_HWCAP_H */ diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index b1d6b7e4b829..7aaf92fff64e 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -107,6 +107,7 @@ void __init riscv_fill_hwcap(void) isa2hwcap['f' - 'a'] = COMPAT_HWCAP_ISA_F; isa2hwcap['d' - 'a'] = COMPAT_HWCAP_ISA_D; isa2hwcap['c' - 'a'] = COMPAT_HWCAP_ISA_C; + isa2hwcap['v' - 'a'] = COMPAT_HWCAP_ISA_V; elf_hwcap = 0; @@ -267,6 +268,16 @@ void __init riscv_fill_hwcap(void) elf_hwcap &= ~COMPAT_HWCAP_ISA_F; } + if (elf_hwcap & COMPAT_HWCAP_ISA_V) { + /* + * ISA string in device tree might have 'v' flag, but + * CONFIG_RISCV_ISA_V is disabled in kernel. + * Clear V flag in elf_hwcap if CONFIG_RISCV_ISA_V is disabled. + */ + if (!IS_ENABLED(CONFIG_RISCV_ISA_V)) + elf_hwcap &= ~COMPAT_HWCAP_ISA_V; + } + memset(print_str, 0, sizeof(print_str)); for (i = 0, j = 0; i < NUM_ALPHA_EXTS; i++) if (riscv_isa[0] & BIT_MASK(i)) -- cgit v1.2.3 From 162e4df137c1fea6557fda3e4cdf5dc6ca6d5510 Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Mon, 5 Jun 2023 11:07:00 +0000 Subject: riscv: hwprobe: Add support for probing V in RISCV_HWPROBE_KEY_IMA_EXT_0 Probing kernel support for Vector extension is available now. This only add detection for V only. Extenions like Zvfh, Zk are not in this scope. Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Evan Green Reviewed-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20230605110724.21391-4-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- Documentation/riscv/hwprobe.rst | 3 +++ arch/riscv/include/uapi/asm/hwprobe.h | 1 + arch/riscv/kernel/sys_riscv.c | 4 ++++ 3 files changed, 8 insertions(+) (limited to 'arch/riscv') diff --git a/Documentation/riscv/hwprobe.rst b/Documentation/riscv/hwprobe.rst index 9f0dd62dcb5d..7431d9d01c73 100644 --- a/Documentation/riscv/hwprobe.rst +++ b/Documentation/riscv/hwprobe.rst @@ -64,6 +64,9 @@ The following keys are defined: * :c:macro:`RISCV_HWPROBE_IMA_C`: The C extension is supported, as defined by version 2.2 of the RISC-V ISA manual. + * :c:macro:`RISCV_HWPROBE_IMA_V`: The V extension is supported, as defined by + version 1.0 of the RISC-V Vector extension manual. + * :c:macro:`RISCV_HWPROBE_KEY_CPUPERF_0`: A bitmask that contains performance information about the selected set of processors. diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h index 8d745a4ad8a2..7c6fdcf7ced5 100644 --- a/arch/riscv/include/uapi/asm/hwprobe.h +++ b/arch/riscv/include/uapi/asm/hwprobe.h @@ -25,6 +25,7 @@ struct riscv_hwprobe { #define RISCV_HWPROBE_KEY_IMA_EXT_0 4 #define RISCV_HWPROBE_IMA_FD (1 << 0) #define RISCV_HWPROBE_IMA_C (1 << 1) +#define RISCV_HWPROBE_IMA_V (1 << 2) #define RISCV_HWPROBE_KEY_CPUPERF_0 5 #define RISCV_HWPROBE_MISALIGNED_UNKNOWN (0 << 0) #define RISCV_HWPROBE_MISALIGNED_EMULATED (1 << 0) diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c index 5db29683ebee..88357a848797 100644 --- a/arch/riscv/kernel/sys_riscv.c +++ b/arch/riscv/kernel/sys_riscv.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include #include @@ -171,6 +172,9 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair, if (riscv_isa_extension_available(NULL, c)) pair->value |= RISCV_HWPROBE_IMA_C; + if (has_vector()) + pair->value |= RISCV_HWPROBE_IMA_V; + break; case RISCV_HWPROBE_KEY_CPUPERF_0: -- cgit v1.2.3 From b5665d2a94325c3244584f504d039a573cfd63e8 Mon Sep 17 00:00:00 2001 From: Greentime Hu Date: Mon, 5 Jun 2023 11:07:01 +0000 Subject: riscv: Add new csr defines related to vector extension Follow the riscv vector spec to add new csr numbers. Acked-by: Guo Ren Co-developed-by: Guo Ren Signed-off-by: Guo Ren Co-developed-by: Vincent Chen Signed-off-by: Vincent Chen Signed-off-by: Greentime Hu Reviewed-by: Palmer Dabbelt Suggested-by: Vineet Gupta Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230605110724.21391-5-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/csr.h | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h index b6acb7ed115f..b98b3b6c9da2 100644 --- a/arch/riscv/include/asm/csr.h +++ b/arch/riscv/include/asm/csr.h @@ -24,16 +24,24 @@ #define SR_FS_CLEAN _AC(0x00004000, UL) #define SR_FS_DIRTY _AC(0x00006000, UL) +#define SR_VS _AC(0x00000600, UL) /* Vector Status */ +#define SR_VS_OFF _AC(0x00000000, UL) +#define SR_VS_INITIAL _AC(0x00000200, UL) +#define SR_VS_CLEAN _AC(0x00000400, UL) +#define SR_VS_DIRTY _AC(0x00000600, UL) + #define SR_XS _AC(0x00018000, UL) /* Extension Status */ #define SR_XS_OFF _AC(0x00000000, UL) #define SR_XS_INITIAL _AC(0x00008000, UL) #define SR_XS_CLEAN _AC(0x00010000, UL) #define SR_XS_DIRTY _AC(0x00018000, UL) +#define SR_FS_VS (SR_FS | SR_VS) /* Vector and Floating-Point Unit */ + #ifndef CONFIG_64BIT -#define SR_SD _AC(0x80000000, UL) /* FS/XS dirty */ +#define SR_SD _AC(0x80000000, UL) /* FS/VS/XS dirty */ #else -#define SR_SD _AC(0x8000000000000000, UL) /* FS/XS dirty */ +#define SR_SD _AC(0x8000000000000000, UL) /* FS/VS/XS dirty */ #endif #ifdef CONFIG_64BIT @@ -375,6 +383,12 @@ #define CSR_MVIPH 0x319 #define CSR_MIPH 0x354 +#define CSR_VSTART 0x8 +#define CSR_VCSR 0xf +#define CSR_VL 0xc20 +#define CSR_VTYPE 0xc21 +#define CSR_VLENB 0xc22 + #ifdef CONFIG_RISCV_M_MODE # define CSR_STATUS CSR_MSTATUS # define CSR_IE CSR_MIE -- cgit v1.2.3 From 6b533828726af4e3609aeb6e5f494e936f9a7cde Mon Sep 17 00:00:00 2001 From: Greentime Hu Date: Mon, 5 Jun 2023 11:07:02 +0000 Subject: riscv: Clear vector regfile on bootup clear vector registers on boot if kernel supports V. Signed-off-by: Greentime Hu Signed-off-by: Vineet Gupta Signed-off-by: Andy Chiu Acked-by: Conor Dooley Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Reviewed-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20230605110724.21391-6-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/head.S | 27 +++++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 4bf6c449d78b..3fd6a4bd9c3e 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -392,7 +392,7 @@ ENTRY(reset_regs) #ifdef CONFIG_FPU csrr t0, CSR_MISA andi t0, t0, (COMPAT_HWCAP_ISA_F | COMPAT_HWCAP_ISA_D) - beqz t0, .Lreset_regs_done + beqz t0, .Lreset_regs_done_fpu li t1, SR_FS csrs CSR_STATUS, t1 @@ -430,8 +430,31 @@ ENTRY(reset_regs) fmv.s.x f31, zero csrw fcsr, 0 /* note that the caller must clear SR_FS */ +.Lreset_regs_done_fpu: #endif /* CONFIG_FPU */ -.Lreset_regs_done: + +#ifdef CONFIG_RISCV_ISA_V + csrr t0, CSR_MISA + li t1, COMPAT_HWCAP_ISA_V + and t0, t0, t1 + beqz t0, .Lreset_regs_done_vector + + /* + * Clear vector registers and reset vcsr + * VLMAX has a defined value, VLEN is a constant, + * and this form of vsetvli is defined to set vl to VLMAX. + */ + li t1, SR_VS + csrs CSR_STATUS, t1 + csrs CSR_VCSR, x0 + vsetvli t1, x0, e8, m8, ta, ma + vmv.v.i v0, 0 + vmv.v.i v8, 0 + vmv.v.i v16, 0 + vmv.v.i v24, 0 + /* note that the caller must clear SR_VS */ +.Lreset_regs_done_vector: +#endif /* CONFIG_RISCV_ISA_V */ ret END(reset_regs) #endif /* CONFIG_RISCV_M_MODE */ -- cgit v1.2.3 From 74abe5a39d3a110f4c87c8ff34b80705009a96e0 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Mon, 5 Jun 2023 11:07:03 +0000 Subject: riscv: Disable Vector Instructions for kernel itself Disable vector instructions execution for kernel mode at its entrances. This helps find illegal uses of vector in the kernel space, which is similar to the fpu. Signed-off-by: Guo Ren Co-developed-by: Vincent Chen Signed-off-by: Vincent Chen Co-developed-by: Han-Kuan Chen Signed-off-by: Han-Kuan Chen Co-developed-by: Greentime Hu Signed-off-by: Greentime Hu Signed-off-by: Vineet Gupta Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Reviewed-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20230605110724.21391-7-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/entry.S | 6 +++--- arch/riscv/kernel/head.S | 12 ++++++------ 2 files changed, 9 insertions(+), 9 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index 3fbb100bc9e4..e9ae284a55c1 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -48,10 +48,10 @@ _save_context: * Disable user-mode memory access as it should only be set in the * actual user copy routines. * - * Disable the FPU to detect illegal usage of floating point in kernel - * space. + * Disable the FPU/Vector to detect illegal usage of floating point + * or vector in kernel space. */ - li t0, SR_SUM | SR_FS + li t0, SR_SUM | SR_FS_VS REG_L s0, TASK_TI_USER_SP(tp) csrrc s1, CSR_STATUS, t0 diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index 3fd6a4bd9c3e..e16bb2185d55 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -140,10 +140,10 @@ secondary_start_sbi: .option pop /* - * Disable FPU to detect illegal usage of - * floating point in kernel space + * Disable FPU & VECTOR to detect illegal usage of + * floating point or vector in kernel space */ - li t0, SR_FS + li t0, SR_FS_VS csrc CSR_STATUS, t0 /* Set trap vector to spin forever to help debug */ @@ -234,10 +234,10 @@ pmp_done: .option pop /* - * Disable FPU to detect illegal usage of - * floating point in kernel space + * Disable FPU & VECTOR to detect illegal usage of + * floating point or vector in kernel space */ - li t0, SR_FS + li t0, SR_FS_VS csrc CSR_STATUS, t0 #ifdef CONFIG_RISCV_BOOT_SPINWAIT -- cgit v1.2.3 From 0a3381a01dcc3d0537732794c007f32e4dfd1efc Mon Sep 17 00:00:00 2001 From: Greentime Hu Date: Mon, 5 Jun 2023 11:07:04 +0000 Subject: riscv: Introduce Vector enable/disable helpers These are small and likely to be frequently called so implement as inline routines (vs. function call). Co-developed-by: Guo Ren Signed-off-by: Guo Ren Co-developed-by: Vincent Chen Signed-off-by: Vincent Chen Signed-off-by: Greentime Hu Signed-off-by: Vineet Gupta Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Reviewed-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20230605110724.21391-8-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/vector.h | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index bdbb05b70151..51bb37232943 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -11,12 +11,23 @@ #ifdef CONFIG_RISCV_ISA_V #include +#include static __always_inline bool has_vector(void) { return riscv_has_extension_unlikely(RISCV_ISA_EXT_v); } +static __always_inline void riscv_v_enable(void) +{ + csr_set(CSR_SSTATUS, SR_VS); +} + +static __always_inline void riscv_v_disable(void) +{ + csr_clear(CSR_SSTATUS, SR_VS); +} + #else /* ! CONFIG_RISCV_ISA_V */ static __always_inline bool has_vector(void) { return false; } -- cgit v1.2.3 From 7017858eb2d7ed7a295be02c71124049a6409295 Mon Sep 17 00:00:00 2001 From: Greentime Hu Date: Mon, 5 Jun 2023 11:07:05 +0000 Subject: riscv: Introduce riscv_v_vsize to record size of Vector context This patch is used to detect the size of CPU vector registers and use riscv_v_vsize to save the size of all the vector registers. It assumes all harts has the same capabilities in a SMP system. If a core detects VLENB that is different from the boot core, then it warns and turns off V support for user space. Co-developed-by: Guo Ren Signed-off-by: Guo Ren Co-developed-by: Vincent Chen Signed-off-by: Vincent Chen Signed-off-by: Greentime Hu Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Reviewed-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20230605110724.21391-9-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/vector.h | 8 ++++++++ arch/riscv/kernel/Makefile | 1 + arch/riscv/kernel/cpufeature.c | 2 ++ arch/riscv/kernel/smpboot.c | 7 +++++++ arch/riscv/kernel/vector.c | 36 ++++++++++++++++++++++++++++++++++++ 5 files changed, 54 insertions(+) create mode 100644 arch/riscv/kernel/vector.c (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index 51bb37232943..df3b5caecc87 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -7,12 +7,16 @@ #define __ASM_RISCV_VECTOR_H #include +#include #ifdef CONFIG_RISCV_ISA_V #include #include +extern unsigned long riscv_v_vsize; +int riscv_v_setup_vsize(void); + static __always_inline bool has_vector(void) { return riscv_has_extension_unlikely(RISCV_ISA_EXT_v); @@ -30,7 +34,11 @@ static __always_inline void riscv_v_disable(void) #else /* ! CONFIG_RISCV_ISA_V */ +struct pt_regs; + +static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; } static __always_inline bool has_vector(void) { return false; } +#define riscv_v_vsize (0) #endif /* CONFIG_RISCV_ISA_V */ diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index fbdccc21418a..c51f34c2756a 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -56,6 +56,7 @@ obj-$(CONFIG_MMU) += vdso.o vdso/ obj-$(CONFIG_RISCV_M_MODE) += traps_misaligned.o obj-$(CONFIG_FPU) += fpu.o +obj-$(CONFIG_RISCV_ISA_V) += vector.o obj-$(CONFIG_SMP) += smpboot.o obj-$(CONFIG_SMP) += smp.o obj-$(CONFIG_SMP) += cpu_ops.o diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 7aaf92fff64e..28032b083463 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -18,6 +18,7 @@ #include #include #include +#include #define NUM_ALPHA_EXTS ('z' - 'a' + 1) @@ -269,6 +270,7 @@ void __init riscv_fill_hwcap(void) } if (elf_hwcap & COMPAT_HWCAP_ISA_V) { + riscv_v_setup_vsize(); /* * ISA string in device tree might have 'v' flag, but * CONFIG_RISCV_ISA_V is disabled in kernel. diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c index 445a4efee267..66011bf2b36e 100644 --- a/arch/riscv/kernel/smpboot.c +++ b/arch/riscv/kernel/smpboot.c @@ -31,6 +31,8 @@ #include #include #include +#include +#include #include "head.h" @@ -169,6 +171,11 @@ asmlinkage __visible void smp_callin(void) set_cpu_online(curr_cpuid, 1); probe_vendor_features(curr_cpuid); + if (has_vector()) { + if (riscv_v_setup_vsize()) + elf_hwcap &= ~COMPAT_HWCAP_ISA_V; + } + /* * Remote TLB flushes are ignored while the CPU is offline, so emit * a local TLB flush right now just in case. diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c new file mode 100644 index 000000000000..120f1ce9abf9 --- /dev/null +++ b/arch/riscv/kernel/vector.c @@ -0,0 +1,36 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2023 SiFive + * Author: Andy Chiu + */ +#include + +#include +#include +#include +#include + +unsigned long riscv_v_vsize __read_mostly; +EXPORT_SYMBOL_GPL(riscv_v_vsize); + +int riscv_v_setup_vsize(void) +{ + unsigned long this_vsize; + + /* There are 32 vector registers with vlenb length. */ + riscv_v_enable(); + this_vsize = csr_read(CSR_VLENB) * 32; + riscv_v_disable(); + + if (!riscv_v_vsize) { + riscv_v_vsize = this_vsize; + return 0; + } + + if (riscv_v_vsize != this_vsize) { + WARN(1, "RISCV_ISA_V only supports one vlenb on SMP systems"); + return -EOPNOTSUPP; + } + + return 0; +} -- cgit v1.2.3 From 03c3fcd9941a172abdea84456eefce2d2b7b415c Mon Sep 17 00:00:00 2001 From: Greentime Hu Date: Mon, 5 Jun 2023 11:07:06 +0000 Subject: riscv: Introduce struct/helpers to save/restore per-task Vector state MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add vector state context struct to be added later in thread_struct. And prepare low-level helper functions to save/restore vector contexts. This include Vector Regfile and CSRs holding dynamic configuration state (vstart, vl, vtype, vcsr). The Vec Register width could be implementation defined, but same for all processes, so that is saved separately. This is not yet wired into final thread_struct - will be done when __switch_to actually starts doing this in later patches. Given the variable (and potentially large) size of regfile, they are saved in dynamically allocated memory, pointed to by datap pointer in __riscv_v_ext_state. Co-developed-by: Vincent Chen Signed-off-by: Vincent Chen Signed-off-by: Greentime Hu Signed-off-by: Vineet Gupta Signed-off-by: Andy Chiu Acked-by: Conor Dooley Reviewed-by: Guo Ren Reviewed-by: Björn Töpel Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Reviewed-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20230605110724.21391-10-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/vector.h | 95 ++++++++++++++++++++++++++++++++++++ arch/riscv/include/uapi/asm/ptrace.h | 17 +++++++ 2 files changed, 112 insertions(+) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index df3b5caecc87..3c29f4eb552a 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -11,8 +11,10 @@ #ifdef CONFIG_RISCV_ISA_V +#include #include #include +#include extern unsigned long riscv_v_vsize; int riscv_v_setup_vsize(void); @@ -22,6 +24,26 @@ static __always_inline bool has_vector(void) return riscv_has_extension_unlikely(RISCV_ISA_EXT_v); } +static inline void __riscv_v_vstate_clean(struct pt_regs *regs) +{ + regs->status = (regs->status & ~SR_VS) | SR_VS_CLEAN; +} + +static inline void riscv_v_vstate_off(struct pt_regs *regs) +{ + regs->status = (regs->status & ~SR_VS) | SR_VS_OFF; +} + +static inline void riscv_v_vstate_on(struct pt_regs *regs) +{ + regs->status = (regs->status & ~SR_VS) | SR_VS_INITIAL; +} + +static inline bool riscv_v_vstate_query(struct pt_regs *regs) +{ + return (regs->status & SR_VS) != 0; +} + static __always_inline void riscv_v_enable(void) { csr_set(CSR_SSTATUS, SR_VS); @@ -32,13 +54,86 @@ static __always_inline void riscv_v_disable(void) csr_clear(CSR_SSTATUS, SR_VS); } +static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest) +{ + asm volatile ( + "csrr %0, " __stringify(CSR_VSTART) "\n\t" + "csrr %1, " __stringify(CSR_VTYPE) "\n\t" + "csrr %2, " __stringify(CSR_VL) "\n\t" + "csrr %3, " __stringify(CSR_VCSR) "\n\t" + : "=r" (dest->vstart), "=r" (dest->vtype), "=r" (dest->vl), + "=r" (dest->vcsr) : :); +} + +static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src) +{ + asm volatile ( + ".option push\n\t" + ".option arch, +v\n\t" + "vsetvl x0, %2, %1\n\t" + ".option pop\n\t" + "csrw " __stringify(CSR_VSTART) ", %0\n\t" + "csrw " __stringify(CSR_VCSR) ", %3\n\t" + : : "r" (src->vstart), "r" (src->vtype), "r" (src->vl), + "r" (src->vcsr) :); +} + +static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to, + void *datap) +{ + unsigned long vl; + + riscv_v_enable(); + __vstate_csr_save(save_to); + asm volatile ( + ".option push\n\t" + ".option arch, +v\n\t" + "vsetvli %0, x0, e8, m8, ta, ma\n\t" + "vse8.v v0, (%1)\n\t" + "add %1, %1, %0\n\t" + "vse8.v v8, (%1)\n\t" + "add %1, %1, %0\n\t" + "vse8.v v16, (%1)\n\t" + "add %1, %1, %0\n\t" + "vse8.v v24, (%1)\n\t" + ".option pop\n\t" + : "=&r" (vl) : "r" (datap) : "memory"); + riscv_v_disable(); +} + +static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_from, + void *datap) +{ + unsigned long vl; + + riscv_v_enable(); + asm volatile ( + ".option push\n\t" + ".option arch, +v\n\t" + "vsetvli %0, x0, e8, m8, ta, ma\n\t" + "vle8.v v0, (%1)\n\t" + "add %1, %1, %0\n\t" + "vle8.v v8, (%1)\n\t" + "add %1, %1, %0\n\t" + "vle8.v v16, (%1)\n\t" + "add %1, %1, %0\n\t" + "vle8.v v24, (%1)\n\t" + ".option pop\n\t" + : "=&r" (vl) : "r" (datap) : "memory"); + __vstate_csr_restore(restore_from); + riscv_v_disable(); +} + #else /* ! CONFIG_RISCV_ISA_V */ struct pt_regs; static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; } static __always_inline bool has_vector(void) { return false; } +static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; } #define riscv_v_vsize (0) +#define riscv_v_vstate_off(regs) do {} while (0) +#define riscv_v_vstate_on(regs) do {} while (0) #endif /* CONFIG_RISCV_ISA_V */ diff --git a/arch/riscv/include/uapi/asm/ptrace.h b/arch/riscv/include/uapi/asm/ptrace.h index 882547f6bd5c..586786d023c4 100644 --- a/arch/riscv/include/uapi/asm/ptrace.h +++ b/arch/riscv/include/uapi/asm/ptrace.h @@ -77,6 +77,23 @@ union __riscv_fp_state { struct __riscv_q_ext_state q; }; +struct __riscv_v_ext_state { + unsigned long vstart; + unsigned long vl; + unsigned long vtype; + unsigned long vcsr; + void *datap; + /* + * In signal handler, datap will be set a correct user stack offset + * and vector registers will be copied to the address of datap + * pointer. + * + * In ptrace syscall, datap will be set to zero and the vector + * registers will be copied to the address right after this + * structure. + */ +}; + #endif /* __ASSEMBLY__ */ #endif /* _UAPI_ASM_RISCV_PTRACE_H */ -- cgit v1.2.3 From 3a2df6323defbb42234aaae804a8ad6af397016a Mon Sep 17 00:00:00 2001 From: Greentime Hu Date: Mon, 5 Jun 2023 11:07:07 +0000 Subject: riscv: Add task switch support for vector MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman Co-developed-by: Nick Knight Signed-off-by: Nick Knight Co-developed-by: Guo Ren Signed-off-by: Guo Ren Co-developed-by: Vincent Chen Signed-off-by: Vincent Chen Co-developed-by: Ruinland Tsai Signed-off-by: Ruinland Tsai Signed-off-by: Greentime Hu Signed-off-by: Vineet Gupta Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Björn Töpel Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230605110724.21391-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/processor.h | 1 + arch/riscv/include/asm/switch_to.h | 3 +++ arch/riscv/include/asm/thread_info.h | 3 +++ arch/riscv/include/asm/vector.h | 38 ++++++++++++++++++++++++++++++++++++ arch/riscv/kernel/process.c | 19 ++++++++++++++++++ 5 files changed, 64 insertions(+) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index 94a0590c6971..f0ddf691ac5e 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -39,6 +39,7 @@ struct thread_struct { unsigned long s[12]; /* s[0]: frame pointer */ struct __riscv_d_ext_state fstate; unsigned long bad_cause; + struct __riscv_v_ext_state vstate; }; /* Whitelist the fstate from the task_struct for hardened usercopy */ diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h index 4b96b13dee27..a727be723c56 100644 --- a/arch/riscv/include/asm/switch_to.h +++ b/arch/riscv/include/asm/switch_to.h @@ -8,6 +8,7 @@ #include #include +#include #include #include #include @@ -78,6 +79,8 @@ do { \ struct task_struct *__next = (next); \ if (has_fpu()) \ __switch_to_fpu(__prev, __next); \ + if (has_vector()) \ + __switch_to_vector(__prev, __next); \ ((last) = __switch_to(__prev, __next)); \ } while (0) diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h index e0d202134b44..97e6f65ec176 100644 --- a/arch/riscv/include/asm/thread_info.h +++ b/arch/riscv/include/asm/thread_info.h @@ -81,6 +81,9 @@ struct thread_info { .preempt_count = INIT_PREEMPT_COUNT, \ } +void arch_release_task_struct(struct task_struct *tsk); +int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); + #endif /* !__ASSEMBLY__ */ /* diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index 3c29f4eb552a..ce6a75e9cf62 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -12,6 +12,9 @@ #ifdef CONFIG_RISCV_ISA_V #include +#include +#include +#include #include #include #include @@ -124,6 +127,38 @@ static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_ riscv_v_disable(); } +static inline void riscv_v_vstate_save(struct task_struct *task, + struct pt_regs *regs) +{ + if ((regs->status & SR_VS) == SR_VS_DIRTY) { + struct __riscv_v_ext_state *vstate = &task->thread.vstate; + + __riscv_v_vstate_save(vstate, vstate->datap); + __riscv_v_vstate_clean(regs); + } +} + +static inline void riscv_v_vstate_restore(struct task_struct *task, + struct pt_regs *regs) +{ + if ((regs->status & SR_VS) != SR_VS_OFF) { + struct __riscv_v_ext_state *vstate = &task->thread.vstate; + + __riscv_v_vstate_restore(vstate, vstate->datap); + __riscv_v_vstate_clean(regs); + } +} + +static inline void __switch_to_vector(struct task_struct *prev, + struct task_struct *next) +{ + struct pt_regs *regs; + + regs = task_pt_regs(prev); + riscv_v_vstate_save(prev, regs); + riscv_v_vstate_restore(next, task_pt_regs(next)); +} + #else /* ! CONFIG_RISCV_ISA_V */ struct pt_regs; @@ -132,6 +167,9 @@ static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; } static __always_inline bool has_vector(void) { return false; } static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; } #define riscv_v_vsize (0) +#define riscv_v_vstate_save(task, regs) do {} while (0) +#define riscv_v_vstate_restore(task, regs) do {} while (0) +#define __switch_to_vector(__prev, __next) do {} while (0) #define riscv_v_vstate_off(regs) do {} while (0) #define riscv_v_vstate_on(regs) do {} while (0) diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index e2a060066730..78eb5ac45888 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -24,6 +24,7 @@ #include #include #include +#include register unsigned long gp_in_global __asm__("gp"); @@ -146,12 +147,28 @@ void flush_thread(void) fstate_off(current, task_pt_regs(current)); memset(¤t->thread.fstate, 0, sizeof(current->thread.fstate)); #endif +#ifdef CONFIG_RISCV_ISA_V + /* Reset vector state */ + riscv_v_vstate_off(task_pt_regs(current)); + kfree(current->thread.vstate.datap); + memset(¤t->thread.vstate, 0, sizeof(struct __riscv_v_ext_state)); +#endif +} + +void arch_release_task_struct(struct task_struct *tsk) +{ + /* Free the vector context of datap. */ + if (has_vector()) + kfree(tsk->thread.vstate.datap); } int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { fstate_save(src, task_pt_regs(src)); *dst = *src; + /* clear entire V context, including datap for a new task */ + memset(&dst->thread.vstate, 0, sizeof(struct __riscv_v_ext_state)); + return 0; } @@ -176,6 +193,8 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) p->thread.s[1] = (unsigned long)args->fn_arg; } else { *childregs = *(current_pt_regs()); + /* Turn off status.VS */ + riscv_v_vstate_off(childregs); if (usp) /* User fork */ childregs->sp = usp; if (clone_flags & CLONE_SETTLS) -- cgit v1.2.3 From cd054837243b5f36ff395c21135ff153871180f1 Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Mon, 5 Jun 2023 11:07:08 +0000 Subject: riscv: Allocate user's vector context in the first-use trap Vector unit is disabled by default for all user processes. Thus, a process will take a trap (illegal instruction) into kernel at the first time when it uses Vector. Only after then, the kernel allocates V context and starts take care of the context for that user process. Suggested-by: Richard Henderson Link: https://lore.kernel.org/r/3923eeee-e4dc-0911-40bf-84c34aee962d@linaro.org Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230605110724.21391-12-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/insn.h | 29 +++++++++++++ arch/riscv/include/asm/vector.h | 2 + arch/riscv/kernel/traps.c | 26 ++++++++++- arch/riscv/kernel/vector.c | 95 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 150 insertions(+), 2 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/insn.h b/arch/riscv/include/asm/insn.h index 8d5c84f2d5ef..4e1505cef8aa 100644 --- a/arch/riscv/include/asm/insn.h +++ b/arch/riscv/include/asm/insn.h @@ -137,6 +137,26 @@ #define RVG_OPCODE_JALR 0x67 #define RVG_OPCODE_JAL 0x6f #define RVG_OPCODE_SYSTEM 0x73 +#define RVG_SYSTEM_CSR_OFF 20 +#define RVG_SYSTEM_CSR_MASK GENMASK(12, 0) + +/* parts of opcode for RVF, RVD and RVQ */ +#define RVFDQ_FL_FS_WIDTH_OFF 12 +#define RVFDQ_FL_FS_WIDTH_MASK GENMASK(3, 0) +#define RVFDQ_FL_FS_WIDTH_W 2 +#define RVFDQ_FL_FS_WIDTH_D 3 +#define RVFDQ_LS_FS_WIDTH_Q 4 +#define RVFDQ_OPCODE_FL 0x07 +#define RVFDQ_OPCODE_FS 0x27 + +/* parts of opcode for RVV */ +#define RVV_OPCODE_VECTOR 0x57 +#define RVV_VL_VS_WIDTH_8 0 +#define RVV_VL_VS_WIDTH_16 5 +#define RVV_VL_VS_WIDTH_32 6 +#define RVV_VL_VS_WIDTH_64 7 +#define RVV_OPCODE_VL RVFDQ_OPCODE_FL +#define RVV_OPCODE_VS RVFDQ_OPCODE_FS /* parts of opcode for RVC*/ #define RVC_OPCODE_C0 0x0 @@ -304,6 +324,15 @@ static __always_inline bool riscv_insn_is_branch(u32 code) (RVC_X(x_, RVC_B_IMM_7_6_OPOFF, RVC_B_IMM_7_6_MASK) << RVC_B_IMM_7_6_OFF) | \ (RVC_IMM_SIGN(x_) << RVC_B_IMM_SIGN_OFF); }) +#define RVG_EXTRACT_SYSTEM_CSR(x) \ + ({typeof(x) x_ = (x); RV_X(x_, RVG_SYSTEM_CSR_OFF, RVG_SYSTEM_CSR_MASK); }) + +#define RVFDQ_EXTRACT_FL_FS_WIDTH(x) \ + ({typeof(x) x_ = (x); RV_X(x_, RVFDQ_FL_FS_WIDTH_OFF, \ + RVFDQ_FL_FS_WIDTH_MASK); }) + +#define RVV_EXRACT_VL_VS_WIDTH(x) RVFDQ_EXTRACT_FL_FS_WIDTH(x) + /* * Get the immediate from a J-type instruction. * diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index ce6a75e9cf62..8e56da67b5cf 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -21,6 +21,7 @@ extern unsigned long riscv_v_vsize; int riscv_v_setup_vsize(void); +bool riscv_v_first_use_handler(struct pt_regs *regs); static __always_inline bool has_vector(void) { @@ -165,6 +166,7 @@ struct pt_regs; static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; } static __always_inline bool has_vector(void) { return false; } +static inline bool riscv_v_first_use_handler(struct pt_regs *regs) { return false; } static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; } #define riscv_v_vsize (0) #define riscv_v_vstate_save(task, regs) do {} while (0) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 8c258b78c925..05ffdcd1424e 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -26,6 +26,7 @@ #include #include #include +#include int show_unhandled_signals = 1; @@ -145,8 +146,29 @@ DO_ERROR_INFO(do_trap_insn_misaligned, SIGBUS, BUS_ADRALN, "instruction address misaligned"); DO_ERROR_INFO(do_trap_insn_fault, SIGSEGV, SEGV_ACCERR, "instruction access fault"); -DO_ERROR_INFO(do_trap_insn_illegal, - SIGILL, ILL_ILLOPC, "illegal instruction"); + +asmlinkage __visible __trap_section void do_trap_insn_illegal(struct pt_regs *regs) +{ + if (user_mode(regs)) { + irqentry_enter_from_user_mode(regs); + + local_irq_enable(); + + if (!riscv_v_first_use_handler(regs)) + do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->epc, + "Oops - illegal instruction"); + + irqentry_exit_to_user_mode(regs); + } else { + irqentry_state_t state = irqentry_nmi_enter(regs); + + do_trap_error(regs, SIGILL, ILL_ILLOPC, regs->epc, + "Oops - illegal instruction"); + + irqentry_nmi_exit(regs, state); + } +} + DO_ERROR_INFO(do_trap_load_fault, SIGSEGV, SEGV_ACCERR, "load access fault"); #ifndef CONFIG_RISCV_M_MODE diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c index 120f1ce9abf9..9d81d1b2a7f3 100644 --- a/arch/riscv/kernel/vector.c +++ b/arch/riscv/kernel/vector.c @@ -4,10 +4,19 @@ * Author: Andy Chiu */ #include +#include +#include +#include +#include +#include +#include +#include +#include #include #include #include +#include #include unsigned long riscv_v_vsize __read_mostly; @@ -34,3 +43,89 @@ int riscv_v_setup_vsize(void) return 0; } + +static bool insn_is_vector(u32 insn_buf) +{ + u32 opcode = insn_buf & __INSN_OPCODE_MASK; + u32 width, csr; + + /* + * All V-related instructions, including CSR operations are 4-Byte. So, + * do not handle if the instruction length is not 4-Byte. + */ + if (unlikely(GET_INSN_LENGTH(insn_buf) != 4)) + return false; + + switch (opcode) { + case RVV_OPCODE_VECTOR: + return true; + case RVV_OPCODE_VL: + case RVV_OPCODE_VS: + width = RVV_EXRACT_VL_VS_WIDTH(insn_buf); + if (width == RVV_VL_VS_WIDTH_8 || width == RVV_VL_VS_WIDTH_16 || + width == RVV_VL_VS_WIDTH_32 || width == RVV_VL_VS_WIDTH_64) + return true; + + break; + case RVG_OPCODE_SYSTEM: + csr = RVG_EXTRACT_SYSTEM_CSR(insn_buf); + if ((csr >= CSR_VSTART && csr <= CSR_VCSR) || + (csr >= CSR_VL && csr <= CSR_VLENB)) + return true; + } + + return false; +} + +static int riscv_v_thread_zalloc(void) +{ + void *datap; + + datap = kzalloc(riscv_v_vsize, GFP_KERNEL); + if (!datap) + return -ENOMEM; + + current->thread.vstate.datap = datap; + memset(¤t->thread.vstate, 0, offsetof(struct __riscv_v_ext_state, + datap)); + return 0; +} + +bool riscv_v_first_use_handler(struct pt_regs *regs) +{ + u32 __user *epc = (u32 __user *)regs->epc; + u32 insn = (u32)regs->badaddr; + + /* Do not handle if V is not supported, or disabled */ + if (!(ELF_HWCAP & COMPAT_HWCAP_ISA_V)) + return false; + + /* If V has been enabled then it is not the first-use trap */ + if (riscv_v_vstate_query(regs)) + return false; + + /* Get the instruction */ + if (!insn) { + if (__get_user(insn, epc)) + return false; + } + + /* Filter out non-V instructions */ + if (!insn_is_vector(insn)) + return false; + + /* Sanity check. datap should be null by the time of the first-use trap */ + WARN_ON(current->thread.vstate.datap); + + /* + * Now we sure that this is a V instruction. And it executes in the + * context where VS has been off. So, try to allocate the user's V + * context and resume execution. + */ + if (riscv_v_thread_zalloc()) { + force_sig(SIGBUS); + return true; + } + riscv_v_vstate_on(regs); + return true; +} -- cgit v1.2.3 From 0c59922c769a1361d4699ef6694b59031767a74e Mon Sep 17 00:00:00 2001 From: Greentime Hu Date: Mon, 5 Jun 2023 11:07:09 +0000 Subject: riscv: Add ptrace vector support This patch adds ptrace support for riscv vector. The vector registers will be saved in datap pointer of __riscv_v_ext_state. This pointer will be set right after the __riscv_v_ext_state data structure then it will be put in ubuf for ptrace system call to get or set. It will check if the datap got from ubuf is set to the correct address or not when the ptrace system call is trying to set the vector registers. Co-developed-by: Vincent Chen Signed-off-by: Vincent Chen Signed-off-by: Greentime Hu Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Palmer Dabbelt Link: https://lore.kernel.org/r/20230605110724.21391-13-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/uapi/asm/ptrace.h | 7 ++++ arch/riscv/kernel/ptrace.c | 70 ++++++++++++++++++++++++++++++++++++ include/uapi/linux/elf.h | 1 + 3 files changed, 78 insertions(+) (limited to 'arch/riscv') diff --git a/arch/riscv/include/uapi/asm/ptrace.h b/arch/riscv/include/uapi/asm/ptrace.h index 586786d023c4..e8d127ec5cf7 100644 --- a/arch/riscv/include/uapi/asm/ptrace.h +++ b/arch/riscv/include/uapi/asm/ptrace.h @@ -94,6 +94,13 @@ struct __riscv_v_ext_state { */ }; +/* + * According to spec: The number of bits in a single vector register, + * VLEN >= ELEN, which must be a power of 2, and must be no greater than + * 2^16 = 65536bits = 8192bytes + */ +#define RISCV_MAX_VLENB (8192) + #endif /* __ASSEMBLY__ */ #endif /* _UAPI_ASM_RISCV_PTRACE_H */ diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c index 23c48b14a0e7..1d572cf3140f 100644 --- a/arch/riscv/kernel/ptrace.c +++ b/arch/riscv/kernel/ptrace.c @@ -7,6 +7,7 @@ * Copied from arch/tile/kernel/ptrace.c */ +#include #include #include #include @@ -24,6 +25,9 @@ enum riscv_regset { #ifdef CONFIG_FPU REGSET_F, #endif +#ifdef CONFIG_RISCV_ISA_V + REGSET_V, +#endif }; static int riscv_gpr_get(struct task_struct *target, @@ -80,6 +84,61 @@ static int riscv_fpr_set(struct task_struct *target, } #endif +#ifdef CONFIG_RISCV_ISA_V +static int riscv_vr_get(struct task_struct *target, + const struct user_regset *regset, + struct membuf to) +{ + struct __riscv_v_ext_state *vstate = &target->thread.vstate; + + if (!riscv_v_vstate_query(task_pt_regs(target))) + return -EINVAL; + + /* + * Ensure the vector registers have been saved to the memory before + * copying them to membuf. + */ + if (target == current) + riscv_v_vstate_save(current, task_pt_regs(current)); + + /* Copy vector header from vstate. */ + membuf_write(&to, vstate, offsetof(struct __riscv_v_ext_state, datap)); + membuf_zero(&to, sizeof(vstate->datap)); + + /* Copy all the vector registers from vstate. */ + return membuf_write(&to, vstate->datap, riscv_v_vsize); +} + +static int riscv_vr_set(struct task_struct *target, + const struct user_regset *regset, + unsigned int pos, unsigned int count, + const void *kbuf, const void __user *ubuf) +{ + int ret, size; + struct __riscv_v_ext_state *vstate = &target->thread.vstate; + + if (!riscv_v_vstate_query(task_pt_regs(target))) + return -EINVAL; + + /* Copy rest of the vstate except datap */ + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vstate, 0, + offsetof(struct __riscv_v_ext_state, datap)); + if (unlikely(ret)) + return ret; + + /* Skip copy datap. */ + size = sizeof(vstate->datap); + count -= size; + ubuf += size; + + /* Copy all the vector registers. */ + pos = 0; + ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, vstate->datap, + 0, riscv_v_vsize); + return ret; +} +#endif + static const struct user_regset riscv_user_regset[] = { [REGSET_X] = { .core_note_type = NT_PRSTATUS, @@ -99,6 +158,17 @@ static const struct user_regset riscv_user_regset[] = { .set = riscv_fpr_set, }, #endif +#ifdef CONFIG_RISCV_ISA_V + [REGSET_V] = { + .core_note_type = NT_RISCV_VECTOR, + .align = 16, + .n = ((32 * RISCV_MAX_VLENB) + + sizeof(struct __riscv_v_ext_state)) / sizeof(__u32), + .size = sizeof(__u32), + .regset_get = riscv_vr_get, + .set = riscv_vr_set, + }, +#endif }; static const struct user_regset_view riscv_user_native_view = { diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h index ac3da855fb19..7d8d9ae36615 100644 --- a/include/uapi/linux/elf.h +++ b/include/uapi/linux/elf.h @@ -440,6 +440,7 @@ typedef struct elf64_shdr { #define NT_MIPS_DSP 0x800 /* MIPS DSP ASE registers */ #define NT_MIPS_FP_MODE 0x801 /* MIPS floating-point mode */ #define NT_MIPS_MSA 0x802 /* MIPS SIMD registers */ +#define NT_RISCV_VECTOR 0x900 /* RISC-V vector registers */ #define NT_LOONGARCH_CPUCFG 0xa00 /* LoongArch CPU config registers */ #define NT_LOONGARCH_CSR 0xa01 /* LoongArch control and status registers */ #define NT_LOONGARCH_LSX 0xa02 /* LoongArch Loongson SIMD Extension registers */ -- cgit v1.2.3 From a45cedaa1ac0da7b30882afb42ff9d5285e9bb44 Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Mon, 5 Jun 2023 11:07:10 +0000 Subject: riscv: signal: check fp-reserved words unconditionally In order to let kernel/user locate and identify an extension context on the existing sigframe, we are going to utilize reserved space of fp and encode the information there. And since the sigcontext has already preserved a space for fp context w or w/o CONFIG_FPU, we move those reserved words checking/setting routine back into generic code. This commit also undone an additional logical change carried by the refactor commit 007f5c3589578 ("Refactor FPU code in signal setup/return procedures"). Originally we did not restore fp context if restoring of gpr have failed. And it was fine on the other side. In such way the kernel could keep the regfiles intact, and potentially react at the failing point of restore. Signed-off-by: Andy Chiu Acked-by: Conor Dooley Acked-by: Heiko Stuebner Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230605110724.21391-14-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/signal.c | 55 +++++++++++++++++++++++----------------------- 1 file changed, 28 insertions(+), 27 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c index 9aff9d720590..6b4a5c90bd87 100644 --- a/arch/riscv/kernel/signal.c +++ b/arch/riscv/kernel/signal.c @@ -40,26 +40,13 @@ static long restore_fp_state(struct pt_regs *regs, { long err; struct __riscv_d_ext_state __user *state = &sc_fpregs->d; - size_t i; err = __copy_from_user(¤t->thread.fstate, state, sizeof(*state)); if (unlikely(err)) return err; fstate_restore(current, regs); - - /* We support no other extension state at this time. */ - for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) { - u32 value; - - err = __get_user(value, &sc_fpregs->q.reserved[i]); - if (unlikely(err)) - break; - if (value != 0) - return -EINVAL; - } - - return err; + return 0; } static long save_fp_state(struct pt_regs *regs, @@ -67,20 +54,9 @@ static long save_fp_state(struct pt_regs *regs, { long err; struct __riscv_d_ext_state __user *state = &sc_fpregs->d; - size_t i; fstate_save(current, regs); err = __copy_to_user(state, ¤t->thread.fstate, sizeof(*state)); - if (unlikely(err)) - return err; - - /* We support no other extension state at this time. */ - for (i = 0; i < ARRAY_SIZE(sc_fpregs->q.reserved); i++) { - err = __put_user(0, &sc_fpregs->q.reserved[i]); - if (unlikely(err)) - break; - } - return err; } #else @@ -92,11 +68,30 @@ static long restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) { long err; + size_t i; + /* sc_regs is structured the same as the start of pt_regs */ err = __copy_from_user(regs, &sc->sc_regs, sizeof(sc->sc_regs)); + if (unlikely(err)) + return err; + /* Restore the floating-point state. */ - if (has_fpu()) - err |= restore_fp_state(regs, &sc->sc_fpregs); + if (has_fpu()) { + err = restore_fp_state(regs, &sc->sc_fpregs); + if (unlikely(err)) + return err; + } + + /* We support no other extension state at this time. */ + for (i = 0; i < ARRAY_SIZE(sc->sc_fpregs.q.reserved); i++) { + u32 value; + + err = __get_user(value, &sc->sc_fpregs.q.reserved[i]); + if (unlikely(err)) + break; + if (value != 0) + return -EINVAL; + } return err; } @@ -147,11 +142,17 @@ static long setup_sigcontext(struct rt_sigframe __user *frame, { struct sigcontext __user *sc = &frame->uc.uc_mcontext; long err; + size_t i; + /* sc_regs is structured the same as the start of pt_regs */ err = __copy_to_user(&sc->sc_regs, regs, sizeof(sc->sc_regs)); /* Save the floating-point state. */ if (has_fpu()) err |= save_fp_state(regs, &sc->sc_fpregs); + /* We support no other extension state at this time. */ + for (i = 0; i < ARRAY_SIZE(sc->sc_fpregs.q.reserved); i++) + err |= __put_user(0, &sc->sc_fpregs.q.reserved[i]); + return err; } -- cgit v1.2.3 From 8ee0b41898fa26f66e32237f179b6989c65600d6 Mon Sep 17 00:00:00 2001 From: Greentime Hu Date: Mon, 5 Jun 2023 11:07:11 +0000 Subject: riscv: signal: Add sigcontext save/restore for vector This patch facilitates the existing fp-reserved words for placement of the first extension's context header on the user's sigframe. A context header consists of a distinct magic word and the size, including the header itself, of an extension on the stack. Then, the frame is followed by the context of that extension, and then a header + context body for another extension if exists. If there is no more extension to come, then the frame must be ended with a null context header. A special case is rv64gc, where the kernel support no extensions requiring to expose additional regfile to the user. In such case the kernel would place the null context header right after the first reserved word of __riscv_q_ext_state when saving sigframe. And the kernel would check if all reserved words are zeros when a signal handler returns. __riscv_q_ext_state---->| |<-__riscv_extra_ext_header ~ ~ .reserved[0]--->|0 |<- .reserved <-------|magic |<- .hdr | |size |_______ end of sc_fpregs | |ext-bdy| | ~ ~ +)size ------->|magic |<- another context header |size | |ext-bdy| ~ ~ |magic:0|<- null context header |size:0 | The vector registers will be saved in datap pointer. The datap pointer will be allocated dynamically when the task needs in kernel space. On the other hand, datap pointer on the sigframe will be set right after the __riscv_v_ext_state data structure. Co-developed-by: Vincent Chen Signed-off-by: Vincent Chen Signed-off-by: Greentime Hu Suggested-by: Vineet Gupta Suggested-by: Richard Henderson Co-developed-by: Andy Chiu Signed-off-by: Andy Chiu Acked-by: Conor Dooley Acked-by: Heiko Stuebner Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230605110724.21391-15-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/uapi/asm/ptrace.h | 15 +++ arch/riscv/include/uapi/asm/sigcontext.h | 16 ++- arch/riscv/kernel/setup.c | 3 + arch/riscv/kernel/signal.c | 174 ++++++++++++++++++++++++++++--- 4 files changed, 193 insertions(+), 15 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/include/uapi/asm/ptrace.h b/arch/riscv/include/uapi/asm/ptrace.h index e8d127ec5cf7..e17c550986a6 100644 --- a/arch/riscv/include/uapi/asm/ptrace.h +++ b/arch/riscv/include/uapi/asm/ptrace.h @@ -71,6 +71,21 @@ struct __riscv_q_ext_state { __u32 reserved[3]; }; +struct __riscv_ctx_hdr { + __u32 magic; + __u32 size; +}; + +struct __riscv_extra_ext_header { + __u32 __padding[129] __attribute__((aligned(16))); + /* + * Reserved for expansion of sigcontext structure. Currently zeroed + * upon signal, and must be zero upon sigreturn. + */ + __u32 reserved; + struct __riscv_ctx_hdr hdr; +}; + union __riscv_fp_state { struct __riscv_f_ext_state f; struct __riscv_d_ext_state d; diff --git a/arch/riscv/include/uapi/asm/sigcontext.h b/arch/riscv/include/uapi/asm/sigcontext.h index 84f2dfcfdbce..8b8a8541673a 100644 --- a/arch/riscv/include/uapi/asm/sigcontext.h +++ b/arch/riscv/include/uapi/asm/sigcontext.h @@ -8,6 +8,17 @@ #include +/* The Magic number for signal context frame header. */ +#define RISCV_V_MAGIC 0x53465457 +#define END_MAGIC 0x0 + +/* The size of END signal context header. */ +#define END_HDR_SIZE 0x0 + +struct __sc_riscv_v_state { + struct __riscv_v_ext_state v_state; +} __attribute__((aligned(16))); + /* * Signal context structure * @@ -16,7 +27,10 @@ */ struct sigcontext { struct user_regs_struct sc_regs; - union __riscv_fp_state sc_fpregs; + union { + union __riscv_fp_state sc_fpregs; + struct __riscv_extra_ext_header sc_extdesc; + }; }; #endif /* _UAPI_ASM_RISCV_SIGCONTEXT_H */ diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 36b026057503..60ebe757ef20 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -262,6 +262,8 @@ static void __init parse_dtb(void) #endif } +extern void __init init_rt_signal_env(void); + void __init setup_arch(char **cmdline_p) { parse_dtb(); @@ -295,6 +297,7 @@ void __init setup_arch(char **cmdline_p) riscv_init_cbo_blocksizes(); riscv_fill_hwcap(); + init_rt_signal_env(); apply_boot_alternatives(); if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) && riscv_isa_extension_available(NULL, ZICBOM)) diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c index 6b4a5c90bd87..c46f3dc039bb 100644 --- a/arch/riscv/kernel/signal.c +++ b/arch/riscv/kernel/signal.c @@ -19,10 +19,12 @@ #include #include #include +#include #include #include extern u32 __user_rt_sigreturn[2]; +static size_t riscv_v_sc_size __ro_after_init; #define DEBUG_SIG 0 @@ -64,12 +66,87 @@ static long save_fp_state(struct pt_regs *regs, #define restore_fp_state(task, regs) (0) #endif +#ifdef CONFIG_RISCV_ISA_V + +static long save_v_state(struct pt_regs *regs, void __user **sc_vec) +{ + struct __riscv_ctx_hdr __user *hdr; + struct __sc_riscv_v_state __user *state; + void __user *datap; + long err; + + hdr = *sc_vec; + /* Place state to the user's signal context space after the hdr */ + state = (struct __sc_riscv_v_state __user *)(hdr + 1); + /* Point datap right after the end of __sc_riscv_v_state */ + datap = state + 1; + + /* datap is designed to be 16 byte aligned for better performance */ + WARN_ON(unlikely(!IS_ALIGNED((unsigned long)datap, 16))); + + riscv_v_vstate_save(current, regs); + /* Copy everything of vstate but datap. */ + err = __copy_to_user(&state->v_state, ¤t->thread.vstate, + offsetof(struct __riscv_v_ext_state, datap)); + /* Copy the pointer datap itself. */ + err |= __put_user(datap, &state->v_state.datap); + /* Copy the whole vector content to user space datap. */ + err |= __copy_to_user(datap, current->thread.vstate.datap, riscv_v_vsize); + /* Copy magic to the user space after saving all vector conetext */ + err |= __put_user(RISCV_V_MAGIC, &hdr->magic); + err |= __put_user(riscv_v_sc_size, &hdr->size); + if (unlikely(err)) + return err; + + /* Only progress the sv_vec if everything has done successfully */ + *sc_vec += riscv_v_sc_size; + return 0; +} + +/* + * Restore Vector extension context from the user's signal frame. This function + * assumes a valid extension header. So magic and size checking must be done by + * the caller. + */ +static long __restore_v_state(struct pt_regs *regs, void __user *sc_vec) +{ + long err; + struct __sc_riscv_v_state __user *state = sc_vec; + void __user *datap; + + /* Copy everything of __sc_riscv_v_state except datap. */ + err = __copy_from_user(¤t->thread.vstate, &state->v_state, + offsetof(struct __riscv_v_ext_state, datap)); + if (unlikely(err)) + return err; + + /* Copy the pointer datap itself. */ + err = __get_user(datap, &state->v_state.datap); + if (unlikely(err)) + return err; + /* + * Copy the whole vector content from user space datap. Use + * copy_from_user to prevent information leak. + */ + err = copy_from_user(current->thread.vstate.datap, datap, riscv_v_vsize); + if (unlikely(err)) + return err; + + riscv_v_vstate_restore(current, regs); + + return err; +} +#else +#define save_v_state(task, regs) (0) +#define __restore_v_state(task, regs) (0) +#endif + static long restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc) { + void __user *sc_ext_ptr = &sc->sc_extdesc.hdr; + __u32 rsvd; long err; - size_t i; - /* sc_regs is structured the same as the start of pt_regs */ err = __copy_from_user(regs, &sc->sc_regs, sizeof(sc->sc_regs)); if (unlikely(err)) @@ -82,32 +159,81 @@ static long restore_sigcontext(struct pt_regs *regs, return err; } - /* We support no other extension state at this time. */ - for (i = 0; i < ARRAY_SIZE(sc->sc_fpregs.q.reserved); i++) { - u32 value; + /* Check the reserved word before extensions parsing */ + err = __get_user(rsvd, &sc->sc_extdesc.reserved); + if (unlikely(err)) + return err; + if (unlikely(rsvd)) + return -EINVAL; + + while (!err) { + __u32 magic, size; + struct __riscv_ctx_hdr __user *head = sc_ext_ptr; - err = __get_user(value, &sc->sc_fpregs.q.reserved[i]); + err |= __get_user(magic, &head->magic); + err |= __get_user(size, &head->size); if (unlikely(err)) + return err; + + sc_ext_ptr += sizeof(*head); + switch (magic) { + case END_MAGIC: + if (size != END_HDR_SIZE) + return -EINVAL; + + return 0; + case RISCV_V_MAGIC: + if (!has_vector() || !riscv_v_vstate_query(regs) || + size != riscv_v_sc_size) + return -EINVAL; + + err = __restore_v_state(regs, sc_ext_ptr); break; - if (value != 0) + default: return -EINVAL; + } + sc_ext_ptr = (void __user *)head + size; } return err; } +static size_t get_rt_frame_size(void) +{ + struct rt_sigframe __user *frame; + size_t frame_size; + size_t total_context_size = 0; + + frame_size = sizeof(*frame); + + if (has_vector() && riscv_v_vstate_query(task_pt_regs(current))) + total_context_size += riscv_v_sc_size; + /* + * Preserved a __riscv_ctx_hdr for END signal context header if an + * extension uses __riscv_extra_ext_header + */ + if (total_context_size) + total_context_size += sizeof(struct __riscv_ctx_hdr); + + frame_size += total_context_size; + + frame_size = round_up(frame_size, 16); + return frame_size; +} + SYSCALL_DEFINE0(rt_sigreturn) { struct pt_regs *regs = current_pt_regs(); struct rt_sigframe __user *frame; struct task_struct *task; sigset_t set; + size_t frame_size = get_rt_frame_size(); /* Always make any pending restarted system calls return -EINTR */ current->restart_block.fn = do_no_restart_syscall; frame = (struct rt_sigframe __user *)regs->sp; - if (!access_ok(frame, sizeof(*frame))) + if (!access_ok(frame, frame_size)) goto badframe; if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) @@ -141,17 +267,22 @@ static long setup_sigcontext(struct rt_sigframe __user *frame, struct pt_regs *regs) { struct sigcontext __user *sc = &frame->uc.uc_mcontext; + struct __riscv_ctx_hdr __user *sc_ext_ptr = &sc->sc_extdesc.hdr; long err; - size_t i; /* sc_regs is structured the same as the start of pt_regs */ err = __copy_to_user(&sc->sc_regs, regs, sizeof(sc->sc_regs)); /* Save the floating-point state. */ if (has_fpu()) err |= save_fp_state(regs, &sc->sc_fpregs); - /* We support no other extension state at this time. */ - for (i = 0; i < ARRAY_SIZE(sc->sc_fpregs.q.reserved); i++) - err |= __put_user(0, &sc->sc_fpregs.q.reserved[i]); + /* Save the vector state. */ + if (has_vector() && riscv_v_vstate_query(regs)) + err |= save_v_state(regs, (void __user **)&sc_ext_ptr); + /* Write zero to fp-reserved space and check it on restore_sigcontext */ + err |= __put_user(0, &sc->sc_extdesc.reserved); + /* And put END __riscv_ctx_hdr at the end. */ + err |= __put_user(END_MAGIC, &sc_ext_ptr->magic); + err |= __put_user(END_HDR_SIZE, &sc_ext_ptr->size); return err; } @@ -176,6 +307,13 @@ static inline void __user *get_sigframe(struct ksignal *ksig, /* Align the stack frame. */ sp &= ~0xfUL; + /* + * Fail if the size of the altstack is not large enough for the + * sigframe construction. + */ + if (current->sas_ss_size && sp < current->sas_ss_sp) + return (void __user __force *)-1UL; + return (void __user *)sp; } @@ -185,9 +323,10 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct rt_sigframe __user *frame; long err = 0; unsigned long __maybe_unused addr; + size_t frame_size = get_rt_frame_size(); - frame = get_sigframe(ksig, regs, sizeof(*frame)); - if (!access_ok(frame, sizeof(*frame))) + frame = get_sigframe(ksig, regs, frame_size); + if (!access_ok(frame, frame_size)) return -EFAULT; err |= copy_siginfo_to_user(&frame->info, &ksig->info); @@ -320,3 +459,10 @@ void arch_do_signal_or_restart(struct pt_regs *regs) */ restore_saved_sigmask(); } + +void init_rt_signal_env(void); +void __init init_rt_signal_env(void) +{ + riscv_v_sc_size = sizeof(struct __riscv_ctx_hdr) + + sizeof(struct __sc_riscv_v_state) + riscv_v_vsize; +} -- cgit v1.2.3 From e92f469b0771e6db9688a58c0e34a8342da6a6bc Mon Sep 17 00:00:00 2001 From: Vincent Chen Date: Mon, 5 Jun 2023 11:07:12 +0000 Subject: riscv: signal: Report signal frame size to userspace via auxv MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The vector register belongs to the signal context. They need to be stored and restored as entering and leaving the signal handler. According to the V-extension specification, the maximum length of the vector registers can be 2^16. Hence, if userspace refers to the MINSIGSTKSZ to create a sigframe, it may not be enough. To resolve this problem, this patch refers to the commit 94b07c1f8c39c ("arm64: signal: Report signal frame size to userspace via auxv") to enable userspace to know the minimum required sigframe size through the auxiliary vector and use it to allocate enough memory for signal context. Note that auxv always reports size of the sigframe as if V exists for all starting processes, whenever the kernel has CONFIG_RISCV_ISA_V. The reason is that users usually reference this value to allocate an alternative signal stack, and the user may use V anytime. So the user must reserve a space for V-context in sigframe in case that the signal handler invokes after the kernel allocating V. Signed-off-by: Greentime Hu Signed-off-by: Vincent Chen Signed-off-by: Andy Chiu Acked-by: Conor Dooley Reviewed-by: Björn Töpel Reviewed-by: Guo Ren Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230605110724.21391-16-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/elf.h | 9 +++++++++ arch/riscv/include/asm/processor.h | 2 ++ arch/riscv/include/uapi/asm/auxvec.h | 1 + arch/riscv/kernel/signal.c | 20 +++++++++++++++----- 4 files changed, 27 insertions(+), 5 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h index 30e7d2455960..ca23c4f6c440 100644 --- a/arch/riscv/include/asm/elf.h +++ b/arch/riscv/include/asm/elf.h @@ -105,6 +105,15 @@ do { \ get_cache_size(3, CACHE_TYPE_UNIFIED)); \ NEW_AUX_ENT(AT_L3_CACHEGEOMETRY, \ get_cache_geometry(3, CACHE_TYPE_UNIFIED)); \ + /* \ + * Should always be nonzero unless there's a kernel bug. \ + * If we haven't determined a sensible value to give to \ + * userspace, omit the entry: \ + */ \ + if (likely(signal_minsigstksz)) \ + NEW_AUX_ENT(AT_MINSIGSTKSZ, signal_minsigstksz); \ + else \ + NEW_AUX_ENT(AT_IGNORE, 0); \ } while (0) #define ARCH_HAS_SETUP_ADDITIONAL_PAGES struct linux_binprm; diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index f0ddf691ac5e..38ded8c5f207 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -7,6 +7,7 @@ #define _ASM_RISCV_PROCESSOR_H #include +#include #include @@ -81,6 +82,7 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid); extern void riscv_fill_hwcap(void); extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); +extern unsigned long signal_minsigstksz __ro_after_init; #endif /* __ASSEMBLY__ */ #endif /* _ASM_RISCV_PROCESSOR_H */ diff --git a/arch/riscv/include/uapi/asm/auxvec.h b/arch/riscv/include/uapi/asm/auxvec.h index fb187a33ce58..10aaa83db89e 100644 --- a/arch/riscv/include/uapi/asm/auxvec.h +++ b/arch/riscv/include/uapi/asm/auxvec.h @@ -35,5 +35,6 @@ /* entries in ARCH_DLINFO */ #define AT_VECTOR_SIZE_ARCH 9 +#define AT_MINSIGSTKSZ 51 #endif /* _UAPI_ASM_RISCV_AUXVEC_H */ diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c index c46f3dc039bb..f117641c1c49 100644 --- a/arch/riscv/kernel/signal.c +++ b/arch/riscv/kernel/signal.c @@ -23,6 +23,8 @@ #include #include +unsigned long signal_minsigstksz __ro_after_init; + extern u32 __user_rt_sigreturn[2]; static size_t riscv_v_sc_size __ro_after_init; @@ -197,7 +199,7 @@ static long restore_sigcontext(struct pt_regs *regs, return err; } -static size_t get_rt_frame_size(void) +static size_t get_rt_frame_size(bool cal_all) { struct rt_sigframe __user *frame; size_t frame_size; @@ -205,8 +207,10 @@ static size_t get_rt_frame_size(void) frame_size = sizeof(*frame); - if (has_vector() && riscv_v_vstate_query(task_pt_regs(current))) - total_context_size += riscv_v_sc_size; + if (has_vector()) { + if (cal_all || riscv_v_vstate_query(task_pt_regs(current))) + total_context_size += riscv_v_sc_size; + } /* * Preserved a __riscv_ctx_hdr for END signal context header if an * extension uses __riscv_extra_ext_header @@ -226,7 +230,7 @@ SYSCALL_DEFINE0(rt_sigreturn) struct rt_sigframe __user *frame; struct task_struct *task; sigset_t set; - size_t frame_size = get_rt_frame_size(); + size_t frame_size = get_rt_frame_size(false); /* Always make any pending restarted system calls return -EINTR */ current->restart_block.fn = do_no_restart_syscall; @@ -323,7 +327,7 @@ static int setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct rt_sigframe __user *frame; long err = 0; unsigned long __maybe_unused addr; - size_t frame_size = get_rt_frame_size(); + size_t frame_size = get_rt_frame_size(false); frame = get_sigframe(ksig, regs, frame_size); if (!access_ok(frame, frame_size)) @@ -465,4 +469,10 @@ void __init init_rt_signal_env(void) { riscv_v_sc_size = sizeof(struct __riscv_ctx_hdr) + sizeof(struct __sc_riscv_v_state) + riscv_v_vsize; + /* + * Determine the stack space required for guaranteed signal delivery. + * The signal_minsigstksz will be populated into the AT_MINSIGSTKSZ entry + * in the auxiliary array at process startup. + */ + signal_minsigstksz = get_rt_frame_size(true); } -- cgit v1.2.3 From 76e22fdc2c2658ab595cdda7368d43d2dc16f3f4 Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Mon, 5 Jun 2023 11:07:13 +0000 Subject: riscv: signal: validate altstack to reflect Vector Some extensions, such as Vector, dynamically change footprint on a signal frame, so MINSIGSTKSZ is no longer accurate. For example, an RV64V implementation with vlen = 512 may occupy 2K + 40 + 12 Bytes of a signal frame with the upcoming support. And processes that do not execute any vector instructions do not need to reserve the extra sigframe. So we need a way to guard the allocation size of the sigframe at process runtime according to current status of V. Thus, provide the function sigaltstack_size_valid() to validate its size based on current allocation status of supported extensions. Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230605110724.21391-17-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/signal.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/riscv') diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c index f117641c1c49..180d951d3624 100644 --- a/arch/riscv/kernel/signal.c +++ b/arch/riscv/kernel/signal.c @@ -476,3 +476,10 @@ void __init init_rt_signal_env(void) */ signal_minsigstksz = get_rt_frame_size(true); } + +#ifdef CONFIG_DYNAMIC_SIGFRAME +bool sigaltstack_size_valid(size_t ss_size) +{ + return ss_size > get_rt_frame_size(false); +} +#endif /* CONFIG_DYNAMIC_SIGFRAME */ -- cgit v1.2.3 From c7cdd96eca2810f5b69c37eb439ec63d59fa1b83 Mon Sep 17 00:00:00 2001 From: Greentime Hu Date: Mon, 5 Jun 2023 11:07:14 +0000 Subject: riscv: prevent stack corruption by reserving task_pt_regs(p) early Early function calls, such as setup_vm(), relocate_enable_mmu(), soc_early_init() etc, are free to operate on stack. However, PT_SIZE_ON_STACK bytes at the head of the kernel stack are purposedly reserved for the placement of per-task register context pointed by task_pt_regs(p). Those functions may corrupt task_pt_regs if we overlap the $sp with it. In fact, we had accidentally corrupted sstatus.VS in some tests, treating the kernel to save V context before V was actually allocated, resulting in a kernel panic. Thus, we should skip PT_SIZE_ON_STACK for $sp before making C function calls from the top-level assembly. Co-developed-by: ShihPo Hung Signed-off-by: ShihPo Hung Co-developed-by: Vincent Chen Signed-off-by: Vincent Chen Signed-off-by: Greentime Hu Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230605110724.21391-18-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/head.S | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/riscv') diff --git a/arch/riscv/kernel/head.S b/arch/riscv/kernel/head.S index e16bb2185d55..11c3b94c4534 100644 --- a/arch/riscv/kernel/head.S +++ b/arch/riscv/kernel/head.S @@ -301,6 +301,7 @@ clear_bss_done: la tp, init_task la sp, init_thread_union + THREAD_SIZE XIP_FIXUP_OFFSET sp + addi sp, sp, -PT_SIZE_ON_STACK #ifdef CONFIG_BUILTIN_DTB la a0, __dtb_start XIP_FIXUP_OFFSET a0 @@ -318,6 +319,7 @@ clear_bss_done: /* Restore C environment */ la tp, init_task la sp, init_thread_union + THREAD_SIZE + addi sp, sp, -PT_SIZE_ON_STACK #ifdef CONFIG_KASAN call kasan_early_init -- cgit v1.2.3 From bf78f1ea6e5108a7ebd55be0853f0716433117a9 Mon Sep 17 00:00:00 2001 From: Vincent Chen Date: Mon, 5 Jun 2023 11:07:15 +0000 Subject: riscv: kvm: Add V extension to KVM ISA Add V extension to KVM isa extension list to enable supporting of V extension on VCPUs. Signed-off-by: Vincent Chen Signed-off-by: Greentime Hu Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Anup Patel Acked-by: Anup Patel Reviewed-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230605110724.21391-19-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/uapi/asm/kvm.h | 1 + arch/riscv/kvm/vcpu.c | 1 + 2 files changed, 2 insertions(+) (limited to 'arch/riscv') diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h index f92790c9481a..8feb57c4c2e8 100644 --- a/arch/riscv/include/uapi/asm/kvm.h +++ b/arch/riscv/include/uapi/asm/kvm.h @@ -121,6 +121,7 @@ enum KVM_RISCV_ISA_EXT_ID { KVM_RISCV_ISA_EXT_ZICBOZ, KVM_RISCV_ISA_EXT_ZBB, KVM_RISCV_ISA_EXT_SSAIA, + KVM_RISCV_ISA_EXT_V, KVM_RISCV_ISA_EXT_MAX, }; diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index 8bd9f2a8a0b9..f3282ff371ca 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -57,6 +57,7 @@ static const unsigned long kvm_isa_ext_arr[] = { [KVM_RISCV_ISA_EXT_H] = RISCV_ISA_EXT_h, [KVM_RISCV_ISA_EXT_I] = RISCV_ISA_EXT_i, [KVM_RISCV_ISA_EXT_M] = RISCV_ISA_EXT_m, + [KVM_RISCV_ISA_EXT_V] = RISCV_ISA_EXT_v, KVM_ISA_EXT_ARR(SSAIA), KVM_ISA_EXT_ARR(SSTC), -- cgit v1.2.3 From 0f4b82579716b12bb88257bd7ea80f25c791fb2c Mon Sep 17 00:00:00 2001 From: Vincent Chen Date: Mon, 5 Jun 2023 11:07:16 +0000 Subject: riscv: KVM: Add vector lazy save/restore support This patch adds vector context save/restore for guest VCPUs. To reduce the impact on KVM performance, the implementation imitates the FP context switch mechanism to lazily store and restore the vector context only when the kernel enters/exits the in-kernel run loop and not during the KVM world switch. Signed-off-by: Vincent Chen Signed-off-by: Greentime Hu Signed-off-by: Andy Chiu Reviewed-by: Anup Patel Acked-by: Anup Patel Link: https://lore.kernel.org/r/20230605110724.21391-20-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/kvm_host.h | 2 + arch/riscv/include/asm/kvm_vcpu_vector.h | 82 ++++++++++++++ arch/riscv/include/uapi/asm/kvm.h | 7 ++ arch/riscv/kvm/Makefile | 1 + arch/riscv/kvm/vcpu.c | 22 ++++ arch/riscv/kvm/vcpu_vector.c | 186 +++++++++++++++++++++++++++++++ 6 files changed, 300 insertions(+) create mode 100644 arch/riscv/include/asm/kvm_vcpu_vector.h create mode 100644 arch/riscv/kvm/vcpu_vector.c (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h index ee0acccb1d3b..bd47a1dc2ff8 100644 --- a/arch/riscv/include/asm/kvm_host.h +++ b/arch/riscv/include/asm/kvm_host.h @@ -15,6 +15,7 @@ #include #include #include +#include #include #include #include @@ -145,6 +146,7 @@ struct kvm_cpu_context { unsigned long sstatus; unsigned long hstatus; union __riscv_fp_state fp; + struct __riscv_v_ext_state vector; }; struct kvm_vcpu_csr { diff --git a/arch/riscv/include/asm/kvm_vcpu_vector.h b/arch/riscv/include/asm/kvm_vcpu_vector.h new file mode 100644 index 000000000000..ff994fdd6d0d --- /dev/null +++ b/arch/riscv/include/asm/kvm_vcpu_vector.h @@ -0,0 +1,82 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2022 SiFive + * + * Authors: + * Vincent Chen + * Greentime Hu + */ + +#ifndef __KVM_VCPU_RISCV_VECTOR_H +#define __KVM_VCPU_RISCV_VECTOR_H + +#include + +#ifdef CONFIG_RISCV_ISA_V +#include +#include + +static __always_inline void __kvm_riscv_vector_save(struct kvm_cpu_context *context) +{ + __riscv_v_vstate_save(&context->vector, context->vector.datap); +} + +static __always_inline void __kvm_riscv_vector_restore(struct kvm_cpu_context *context) +{ + __riscv_v_vstate_restore(&context->vector, context->vector.datap); +} + +void kvm_riscv_vcpu_vector_reset(struct kvm_vcpu *vcpu); +void kvm_riscv_vcpu_guest_vector_save(struct kvm_cpu_context *cntx, + unsigned long *isa); +void kvm_riscv_vcpu_guest_vector_restore(struct kvm_cpu_context *cntx, + unsigned long *isa); +void kvm_riscv_vcpu_host_vector_save(struct kvm_cpu_context *cntx); +void kvm_riscv_vcpu_host_vector_restore(struct kvm_cpu_context *cntx); +int kvm_riscv_vcpu_alloc_vector_context(struct kvm_vcpu *vcpu, + struct kvm_cpu_context *cntx); +void kvm_riscv_vcpu_free_vector_context(struct kvm_vcpu *vcpu); +#else + +struct kvm_cpu_context; + +static inline void kvm_riscv_vcpu_vector_reset(struct kvm_vcpu *vcpu) +{ +} + +static inline void kvm_riscv_vcpu_guest_vector_save(struct kvm_cpu_context *cntx, + unsigned long *isa) +{ +} + +static inline void kvm_riscv_vcpu_guest_vector_restore(struct kvm_cpu_context *cntx, + unsigned long *isa) +{ +} + +static inline void kvm_riscv_vcpu_host_vector_save(struct kvm_cpu_context *cntx) +{ +} + +static inline void kvm_riscv_vcpu_host_vector_restore(struct kvm_cpu_context *cntx) +{ +} + +static inline int kvm_riscv_vcpu_alloc_vector_context(struct kvm_vcpu *vcpu, + struct kvm_cpu_context *cntx) +{ + return 0; +} + +static inline void kvm_riscv_vcpu_free_vector_context(struct kvm_vcpu *vcpu) +{ +} +#endif + +int kvm_riscv_vcpu_get_reg_vector(struct kvm_vcpu *vcpu, + const struct kvm_one_reg *reg, + unsigned long rtype); +int kvm_riscv_vcpu_set_reg_vector(struct kvm_vcpu *vcpu, + const struct kvm_one_reg *reg, + unsigned long rtype); +#endif diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h index 8feb57c4c2e8..855c047e86d4 100644 --- a/arch/riscv/include/uapi/asm/kvm.h +++ b/arch/riscv/include/uapi/asm/kvm.h @@ -204,6 +204,13 @@ enum KVM_RISCV_SBI_EXT_ID { #define KVM_REG_RISCV_SBI_MULTI_REG_LAST \ KVM_REG_RISCV_SBI_MULTI_REG(KVM_RISCV_SBI_EXT_MAX - 1) +/* V extension registers are mapped as type 9 */ +#define KVM_REG_RISCV_VECTOR (0x09 << KVM_REG_RISCV_TYPE_SHIFT) +#define KVM_REG_RISCV_VECTOR_CSR_REG(name) \ + (offsetof(struct __riscv_v_ext_state, name) / sizeof(unsigned long)) +#define KVM_REG_RISCV_VECTOR_REG(n) \ + ((n) + sizeof(struct __riscv_v_ext_state) / sizeof(unsigned long)) + #endif #endif /* __LINUX_KVM_RISCV_H */ diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile index 8031b8912a0d..7b4c21f9aa6a 100644 --- a/arch/riscv/kvm/Makefile +++ b/arch/riscv/kvm/Makefile @@ -17,6 +17,7 @@ kvm-y += mmu.o kvm-y += vcpu.o kvm-y += vcpu_exit.o kvm-y += vcpu_fp.o +kvm-y += vcpu_vector.o kvm-y += vcpu_insn.o kvm-y += vcpu_switch.o kvm-y += vcpu_sbi.o diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index f3282ff371ca..e5e045852e6a 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -22,6 +22,8 @@ #include #include #include +#include +#include const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = { KVM_GENERIC_VCPU_STATS(), @@ -139,6 +141,8 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu) kvm_riscv_vcpu_fp_reset(vcpu); + kvm_riscv_vcpu_vector_reset(vcpu); + kvm_riscv_vcpu_timer_reset(vcpu); kvm_riscv_vcpu_aia_reset(vcpu); @@ -199,6 +203,9 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu) cntx->hstatus |= HSTATUS_SPVP; cntx->hstatus |= HSTATUS_SPV; + if (kvm_riscv_vcpu_alloc_vector_context(vcpu, cntx)) + return -ENOMEM; + /* By default, make CY, TM, and IR counters accessible in VU mode */ reset_csr->scounteren = 0x7; @@ -242,6 +249,9 @@ void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu) /* Free unused pages pre-allocated for G-stage page table mappings */ kvm_mmu_free_memory_cache(&vcpu->arch.mmu_page_cache); + + /* Free vector context space for host and guest kernel */ + kvm_riscv_vcpu_free_vector_context(vcpu); } int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu) @@ -680,6 +690,9 @@ static int kvm_riscv_vcpu_set_reg(struct kvm_vcpu *vcpu, return kvm_riscv_vcpu_set_reg_isa_ext(vcpu, reg); case KVM_REG_RISCV_SBI_EXT: return kvm_riscv_vcpu_set_reg_sbi_ext(vcpu, reg); + case KVM_REG_RISCV_VECTOR: + return kvm_riscv_vcpu_set_reg_vector(vcpu, reg, + KVM_REG_RISCV_VECTOR); default: break; } @@ -709,6 +722,9 @@ static int kvm_riscv_vcpu_get_reg(struct kvm_vcpu *vcpu, return kvm_riscv_vcpu_get_reg_isa_ext(vcpu, reg); case KVM_REG_RISCV_SBI_EXT: return kvm_riscv_vcpu_get_reg_sbi_ext(vcpu, reg); + case KVM_REG_RISCV_VECTOR: + return kvm_riscv_vcpu_get_reg_vector(vcpu, reg, + KVM_REG_RISCV_VECTOR); default: break; } @@ -1003,6 +1019,9 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) kvm_riscv_vcpu_host_fp_save(&vcpu->arch.host_context); kvm_riscv_vcpu_guest_fp_restore(&vcpu->arch.guest_context, vcpu->arch.isa); + kvm_riscv_vcpu_host_vector_save(&vcpu->arch.host_context); + kvm_riscv_vcpu_guest_vector_restore(&vcpu->arch.guest_context, + vcpu->arch.isa); kvm_riscv_vcpu_aia_load(vcpu, cpu); @@ -1022,6 +1041,9 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) kvm_riscv_vcpu_host_fp_restore(&vcpu->arch.host_context); kvm_riscv_vcpu_timer_save(vcpu); + kvm_riscv_vcpu_guest_vector_save(&vcpu->arch.guest_context, + vcpu->arch.isa); + kvm_riscv_vcpu_host_vector_restore(&vcpu->arch.host_context); csr->vsstatus = csr_read(CSR_VSSTATUS); csr->vsie = csr_read(CSR_VSIE); diff --git a/arch/riscv/kvm/vcpu_vector.c b/arch/riscv/kvm/vcpu_vector.c new file mode 100644 index 000000000000..edd2eecbddc2 --- /dev/null +++ b/arch/riscv/kvm/vcpu_vector.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2022 SiFive + * + * Authors: + * Vincent Chen + * Greentime Hu + */ + +#include +#include +#include +#include +#include +#include +#include + +#ifdef CONFIG_RISCV_ISA_V +void kvm_riscv_vcpu_vector_reset(struct kvm_vcpu *vcpu) +{ + unsigned long *isa = vcpu->arch.isa; + struct kvm_cpu_context *cntx = &vcpu->arch.guest_context; + + cntx->sstatus &= ~SR_VS; + if (riscv_isa_extension_available(isa, v)) { + cntx->sstatus |= SR_VS_INITIAL; + WARN_ON(!cntx->vector.datap); + memset(cntx->vector.datap, 0, riscv_v_vsize); + } else { + cntx->sstatus |= SR_VS_OFF; + } +} + +static void kvm_riscv_vcpu_vector_clean(struct kvm_cpu_context *cntx) +{ + cntx->sstatus &= ~SR_VS; + cntx->sstatus |= SR_VS_CLEAN; +} + +void kvm_riscv_vcpu_guest_vector_save(struct kvm_cpu_context *cntx, + unsigned long *isa) +{ + if ((cntx->sstatus & SR_VS) == SR_VS_DIRTY) { + if (riscv_isa_extension_available(isa, v)) + __kvm_riscv_vector_save(cntx); + kvm_riscv_vcpu_vector_clean(cntx); + } +} + +void kvm_riscv_vcpu_guest_vector_restore(struct kvm_cpu_context *cntx, + unsigned long *isa) +{ + if ((cntx->sstatus & SR_VS) != SR_VS_OFF) { + if (riscv_isa_extension_available(isa, v)) + __kvm_riscv_vector_restore(cntx); + kvm_riscv_vcpu_vector_clean(cntx); + } +} + +void kvm_riscv_vcpu_host_vector_save(struct kvm_cpu_context *cntx) +{ + /* No need to check host sstatus as it can be modified outside */ + if (riscv_isa_extension_available(NULL, v)) + __kvm_riscv_vector_save(cntx); +} + +void kvm_riscv_vcpu_host_vector_restore(struct kvm_cpu_context *cntx) +{ + if (riscv_isa_extension_available(NULL, v)) + __kvm_riscv_vector_restore(cntx); +} + +int kvm_riscv_vcpu_alloc_vector_context(struct kvm_vcpu *vcpu, + struct kvm_cpu_context *cntx) +{ + cntx->vector.datap = kmalloc(riscv_v_vsize, GFP_KERNEL); + if (!cntx->vector.datap) + return -ENOMEM; + + vcpu->arch.host_context.vector.datap = kzalloc(riscv_v_vsize, GFP_KERNEL); + if (!vcpu->arch.host_context.vector.datap) + return -ENOMEM; + + return 0; +} + +void kvm_riscv_vcpu_free_vector_context(struct kvm_vcpu *vcpu) +{ + kfree(vcpu->arch.guest_reset_context.vector.datap); + kfree(vcpu->arch.host_context.vector.datap); +} +#endif + +static void *kvm_riscv_vcpu_vreg_addr(struct kvm_vcpu *vcpu, + unsigned long reg_num, + size_t reg_size) +{ + struct kvm_cpu_context *cntx = &vcpu->arch.guest_context; + void *reg_val; + size_t vlenb = riscv_v_vsize / 32; + + if (reg_num < KVM_REG_RISCV_VECTOR_REG(0)) { + if (reg_size != sizeof(unsigned long)) + return NULL; + switch (reg_num) { + case KVM_REG_RISCV_VECTOR_CSR_REG(vstart): + reg_val = &cntx->vector.vstart; + break; + case KVM_REG_RISCV_VECTOR_CSR_REG(vl): + reg_val = &cntx->vector.vl; + break; + case KVM_REG_RISCV_VECTOR_CSR_REG(vtype): + reg_val = &cntx->vector.vtype; + break; + case KVM_REG_RISCV_VECTOR_CSR_REG(vcsr): + reg_val = &cntx->vector.vcsr; + break; + case KVM_REG_RISCV_VECTOR_CSR_REG(datap): + default: + return NULL; + } + } else if (reg_num <= KVM_REG_RISCV_VECTOR_REG(31)) { + if (reg_size != vlenb) + return NULL; + reg_val = cntx->vector.datap + + (reg_num - KVM_REG_RISCV_VECTOR_REG(0)) * vlenb; + } else { + return NULL; + } + + return reg_val; +} + +int kvm_riscv_vcpu_get_reg_vector(struct kvm_vcpu *vcpu, + const struct kvm_one_reg *reg, + unsigned long rtype) +{ + unsigned long *isa = vcpu->arch.isa; + unsigned long __user *uaddr = + (unsigned long __user *)(unsigned long)reg->addr; + unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK | + KVM_REG_SIZE_MASK | + rtype); + void *reg_val = NULL; + size_t reg_size = KVM_REG_SIZE(reg->id); + + if (rtype == KVM_REG_RISCV_VECTOR && + riscv_isa_extension_available(isa, v)) { + reg_val = kvm_riscv_vcpu_vreg_addr(vcpu, reg_num, reg_size); + } + + if (!reg_val) + return -EINVAL; + + if (copy_to_user(uaddr, reg_val, reg_size)) + return -EFAULT; + + return 0; +} + +int kvm_riscv_vcpu_set_reg_vector(struct kvm_vcpu *vcpu, + const struct kvm_one_reg *reg, + unsigned long rtype) +{ + unsigned long *isa = vcpu->arch.isa; + unsigned long __user *uaddr = + (unsigned long __user *)(unsigned long)reg->addr; + unsigned long reg_num = reg->id & ~(KVM_REG_ARCH_MASK | + KVM_REG_SIZE_MASK | + rtype); + void *reg_val = NULL; + size_t reg_size = KVM_REG_SIZE(reg->id); + + if (rtype == KVM_REG_RISCV_VECTOR && + riscv_isa_extension_available(isa, v)) { + reg_val = kvm_riscv_vcpu_vreg_addr(vcpu, reg_num, reg_size); + } + + if (!reg_val) + return -EINVAL; + + if (copy_from_user(reg_val, uaddr, reg_size)) + return -EFAULT; + + return 0; +} -- cgit v1.2.3 From 50724efcb370c61c64f75614763fb411e087f70c Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Mon, 5 Jun 2023 11:07:17 +0000 Subject: riscv: hwcap: change ELF_HWCAP to a function Using a function is flexible to represent ELF_HWCAP. So the kernel may encode hwcap reflecting supported hardware features just at the moment of the start of each program. This will be helpful when we introduce prctl/sysctl interface to control per-process availability of Vector extension in following patches. Programs started with V disabled should see V masked off in theirs ELF_HWCAP. Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230605110724.21391-21-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/elf.h | 2 +- arch/riscv/include/asm/hwcap.h | 2 ++ arch/riscv/kernel/cpufeature.c | 5 +++++ 3 files changed, 8 insertions(+), 1 deletion(-) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h index ca23c4f6c440..c24280774caf 100644 --- a/arch/riscv/include/asm/elf.h +++ b/arch/riscv/include/asm/elf.h @@ -66,7 +66,7 @@ extern bool compat_elf_check_arch(Elf32_Ehdr *hdr); * via a bitmap that coorespends to each single-letter ISA extension. This is * essentially defunct, but will remain for compatibility with userspace. */ -#define ELF_HWCAP (elf_hwcap & ((1UL << RISCV_ISA_EXT_BASE) - 1)) +#define ELF_HWCAP riscv_get_elf_hwcap() extern unsigned long elf_hwcap; /* diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index 574385930ba7..e6c288ac4581 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -61,6 +61,8 @@ #include +unsigned long riscv_get_elf_hwcap(void); + struct riscv_isa_ext_data { /* Name of the extension displayed to userspace via /proc/cpuinfo */ char uprop[RISCV_ISA_EXT_NAME_LEN_MAX]; diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 28032b083463..29c0680652a0 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -293,6 +293,11 @@ void __init riscv_fill_hwcap(void) pr_info("riscv: ELF capabilities %s\n", print_str); } +unsigned long riscv_get_elf_hwcap(void) +{ + return (elf_hwcap & ((1UL << RISCV_ISA_EXT_BASE) - 1)); +} + #ifdef CONFIG_RISCV_ALTERNATIVE /* * Alternative patch sites consider 48 bits when determining when to patch -- cgit v1.2.3 From 1fd96a3e9d5d4febe1a8486590ad52c048d1be77 Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Mon, 5 Jun 2023 11:07:18 +0000 Subject: riscv: Add prctl controls for userspace vector management This patch add two riscv-specific prctls, to allow usespace control the use of vector unit: * PR_RISCV_V_SET_CONTROL: control the permission to use Vector at next, or all following execve for a thread. Turning off a thread's Vector live is not possible since libraries may have registered ifunc that may execute Vector instructions. * PR_RISCV_V_GET_CONTROL: get the same permission setting for the current thread, and the setting for following execve(s). Signed-off-by: Andy Chiu Reviewed-by: Greentime Hu Reviewed-by: Vincent Chen Link: https://lore.kernel.org/r/20230605110724.21391-22-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/processor.h | 10 ++++ arch/riscv/include/asm/vector.h | 4 ++ arch/riscv/kernel/cpufeature.c | 9 ++- arch/riscv/kernel/process.c | 1 + arch/riscv/kernel/vector.c | 114 +++++++++++++++++++++++++++++++++++++ arch/riscv/kvm/vcpu.c | 2 + include/uapi/linux/prctl.h | 11 ++++ kernel/sys.c | 12 ++++ 8 files changed, 162 insertions(+), 1 deletion(-) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index 38ded8c5f207..e82af1097e26 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -40,6 +40,7 @@ struct thread_struct { unsigned long s[12]; /* s[0]: frame pointer */ struct __riscv_d_ext_state fstate; unsigned long bad_cause; + unsigned long vstate_ctrl; struct __riscv_v_ext_state vstate; }; @@ -83,6 +84,15 @@ extern void riscv_fill_hwcap(void); extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); extern unsigned long signal_minsigstksz __ro_after_init; + +#ifdef CONFIG_RISCV_ISA_V +/* Userspace interface for PR_RISCV_V_{SET,GET}_VS prctl()s: */ +#define RISCV_V_SET_CONTROL(arg) riscv_v_vstate_ctrl_set_current(arg) +#define RISCV_V_GET_CONTROL() riscv_v_vstate_ctrl_get_current() +extern long riscv_v_vstate_ctrl_set_current(unsigned long arg); +extern long riscv_v_vstate_ctrl_get_current(void); +#endif /* CONFIG_RISCV_ISA_V */ + #endif /* __ASSEMBLY__ */ #endif /* _ASM_RISCV_PROCESSOR_H */ diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index 8e56da67b5cf..04c0b07bf6cd 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -160,6 +160,9 @@ static inline void __switch_to_vector(struct task_struct *prev, riscv_v_vstate_restore(next, task_pt_regs(next)); } +void riscv_v_vstate_ctrl_init(struct task_struct *tsk); +bool riscv_v_vstate_ctrl_user_allowed(void); + #else /* ! CONFIG_RISCV_ISA_V */ struct pt_regs; @@ -168,6 +171,7 @@ static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; } static __always_inline bool has_vector(void) { return false; } static inline bool riscv_v_first_use_handler(struct pt_regs *regs) { return false; } static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; } +static inline bool riscv_v_vstate_ctrl_user_allowed(void) { return false; } #define riscv_v_vsize (0) #define riscv_v_vstate_save(task, regs) do {} while (0) #define riscv_v_vstate_restore(task, regs) do {} while (0) diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 29c0680652a0..8ae43e40fffc 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -295,7 +295,14 @@ void __init riscv_fill_hwcap(void) unsigned long riscv_get_elf_hwcap(void) { - return (elf_hwcap & ((1UL << RISCV_ISA_EXT_BASE) - 1)); + unsigned long hwcap; + + hwcap = (elf_hwcap & ((1UL << RISCV_ISA_EXT_BASE) - 1)); + + if (!riscv_v_vstate_ctrl_user_allowed()) + hwcap &= ~COMPAT_HWCAP_ISA_V; + + return hwcap; } #ifdef CONFIG_RISCV_ALTERNATIVE diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index 78eb5ac45888..e32d737e039f 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -149,6 +149,7 @@ void flush_thread(void) #endif #ifdef CONFIG_RISCV_ISA_V /* Reset vector state */ + riscv_v_vstate_ctrl_init(current); riscv_v_vstate_off(task_pt_regs(current)); kfree(current->thread.vstate.datap); memset(¤t->thread.vstate, 0, sizeof(struct __riscv_v_ext_state)); diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c index 9d81d1b2a7f3..a7dec9230164 100644 --- a/arch/riscv/kernel/vector.c +++ b/arch/riscv/kernel/vector.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include @@ -19,6 +20,8 @@ #include #include +static bool riscv_v_implicit_uacc = IS_ENABLED(CONFIG_RISCV_ISA_V_DEFAULT_ENABLE); + unsigned long riscv_v_vsize __read_mostly; EXPORT_SYMBOL_GPL(riscv_v_vsize); @@ -91,6 +94,43 @@ static int riscv_v_thread_zalloc(void) return 0; } +#define VSTATE_CTRL_GET_CUR(x) ((x) & PR_RISCV_V_VSTATE_CTRL_CUR_MASK) +#define VSTATE_CTRL_GET_NEXT(x) (((x) & PR_RISCV_V_VSTATE_CTRL_NEXT_MASK) >> 2) +#define VSTATE_CTRL_MAKE_NEXT(x) (((x) << 2) & PR_RISCV_V_VSTATE_CTRL_NEXT_MASK) +#define VSTATE_CTRL_GET_INHERIT(x) (!!((x) & PR_RISCV_V_VSTATE_CTRL_INHERIT)) +static inline int riscv_v_ctrl_get_cur(struct task_struct *tsk) +{ + return VSTATE_CTRL_GET_CUR(tsk->thread.vstate_ctrl); +} + +static inline int riscv_v_ctrl_get_next(struct task_struct *tsk) +{ + return VSTATE_CTRL_GET_NEXT(tsk->thread.vstate_ctrl); +} + +static inline bool riscv_v_ctrl_test_inherit(struct task_struct *tsk) +{ + return VSTATE_CTRL_GET_INHERIT(tsk->thread.vstate_ctrl); +} + +static inline void riscv_v_ctrl_set(struct task_struct *tsk, int cur, int nxt, + bool inherit) +{ + unsigned long ctrl; + + ctrl = cur & PR_RISCV_V_VSTATE_CTRL_CUR_MASK; + ctrl |= VSTATE_CTRL_MAKE_NEXT(nxt); + if (inherit) + ctrl |= PR_RISCV_V_VSTATE_CTRL_INHERIT; + tsk->thread.vstate_ctrl = ctrl; +} + +bool riscv_v_vstate_ctrl_user_allowed(void) +{ + return riscv_v_ctrl_get_cur(current) == PR_RISCV_V_VSTATE_CTRL_ON; +} +EXPORT_SYMBOL_GPL(riscv_v_vstate_ctrl_user_allowed); + bool riscv_v_first_use_handler(struct pt_regs *regs) { u32 __user *epc = (u32 __user *)regs->epc; @@ -129,3 +169,77 @@ bool riscv_v_first_use_handler(struct pt_regs *regs) riscv_v_vstate_on(regs); return true; } + +void riscv_v_vstate_ctrl_init(struct task_struct *tsk) +{ + bool inherit; + int cur, next; + + if (!has_vector()) + return; + + next = riscv_v_ctrl_get_next(tsk); + if (!next) { + if (riscv_v_implicit_uacc) + cur = PR_RISCV_V_VSTATE_CTRL_ON; + else + cur = PR_RISCV_V_VSTATE_CTRL_OFF; + } else { + cur = next; + } + /* Clear next mask if inherit-bit is not set */ + inherit = riscv_v_ctrl_test_inherit(tsk); + if (!inherit) + next = PR_RISCV_V_VSTATE_CTRL_DEFAULT; + + riscv_v_ctrl_set(tsk, cur, next, inherit); +} + +long riscv_v_vstate_ctrl_get_current(void) +{ + if (!has_vector()) + return -EINVAL; + + return current->thread.vstate_ctrl & PR_RISCV_V_VSTATE_CTRL_MASK; +} + +long riscv_v_vstate_ctrl_set_current(unsigned long arg) +{ + bool inherit; + int cur, next; + + if (!has_vector()) + return -EINVAL; + + if (arg & ~PR_RISCV_V_VSTATE_CTRL_MASK) + return -EINVAL; + + cur = VSTATE_CTRL_GET_CUR(arg); + switch (cur) { + case PR_RISCV_V_VSTATE_CTRL_OFF: + /* Do not allow user to turn off V if current is not off */ + if (riscv_v_ctrl_get_cur(current) != PR_RISCV_V_VSTATE_CTRL_OFF) + return -EPERM; + + break; + case PR_RISCV_V_VSTATE_CTRL_ON: + break; + case PR_RISCV_V_VSTATE_CTRL_DEFAULT: + cur = riscv_v_ctrl_get_cur(current); + break; + default: + return -EINVAL; + } + + next = VSTATE_CTRL_GET_NEXT(arg); + inherit = VSTATE_CTRL_GET_INHERIT(arg); + switch (next) { + case PR_RISCV_V_VSTATE_CTRL_DEFAULT: + case PR_RISCV_V_VSTATE_CTRL_OFF: + case PR_RISCV_V_VSTATE_CTRL_ON: + riscv_v_ctrl_set(current, cur, next, inherit); + return 0; + } + + return -EINVAL; +} diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c index e5e045852e6a..de24127e7e93 100644 --- a/arch/riscv/kvm/vcpu.c +++ b/arch/riscv/kvm/vcpu.c @@ -88,6 +88,8 @@ static bool kvm_riscv_vcpu_isa_enable_allowed(unsigned long ext) switch (ext) { case KVM_RISCV_ISA_EXT_H: return false; + case KVM_RISCV_ISA_EXT_V: + return riscv_v_vstate_ctrl_user_allowed(); default: break; } diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index f23d9a16507f..3c36aeade991 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -294,4 +294,15 @@ struct prctl_mm_map { #define PR_SET_MEMORY_MERGE 67 #define PR_GET_MEMORY_MERGE 68 + +#define PR_RISCV_V_SET_CONTROL 69 +#define PR_RISCV_V_GET_CONTROL 70 +# define PR_RISCV_V_VSTATE_CTRL_DEFAULT 0 +# define PR_RISCV_V_VSTATE_CTRL_OFF 1 +# define PR_RISCV_V_VSTATE_CTRL_ON 2 +# define PR_RISCV_V_VSTATE_CTRL_INHERIT (1 << 4) +# define PR_RISCV_V_VSTATE_CTRL_CUR_MASK 0x3 +# define PR_RISCV_V_VSTATE_CTRL_NEXT_MASK 0xc +# define PR_RISCV_V_VSTATE_CTRL_MASK 0x1f + #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/sys.c b/kernel/sys.c index 339fee3eff6a..05f838929e72 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -140,6 +140,12 @@ #ifndef GET_TAGGED_ADDR_CTRL # define GET_TAGGED_ADDR_CTRL() (-EINVAL) #endif +#ifndef RISCV_V_SET_CONTROL +# define RISCV_V_SET_CONTROL(a) (-EINVAL) +#endif +#ifndef RISCV_V_GET_CONTROL +# define RISCV_V_GET_CONTROL() (-EINVAL) +#endif /* * this is where the system-wide overflow UID and GID are defined, for @@ -2708,6 +2714,12 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, error = !!test_bit(MMF_VM_MERGE_ANY, &me->mm->flags); break; #endif + case PR_RISCV_V_SET_CONTROL: + error = RISCV_V_SET_CONTROL(arg2); + break; + case PR_RISCV_V_GET_CONTROL: + error = RISCV_V_GET_CONTROL(); + break; default: error = -EINVAL; break; -- cgit v1.2.3 From 7ca7a7b9b635dbf8428f8e3bb8ea9e9ff5c79bfc Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Mon, 5 Jun 2023 11:07:19 +0000 Subject: riscv: Add sysctl to set the default vector rule for new processes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To support Vector extension, the series exports variable-length vector registers on the signal frame. However, this potentially breaks abi if processing vector registers is required in the signal handler for old binaries. For example, there is such need if user-level context switch is triggerred via signals[1]. For this reason, it is best to leave a decision to distro maintainers, where the enablement of userspace Vector for new launching programs can be controlled. Developers may also need the switch to experiment with. The parameter is configurable through sysctl interface so a distro may turn off Vector early at init script if the break really happens in the wild. The switch will only take effects on new execve() calls once set. This will not effect existing processes that do not call execve(), nor processes which has been set with a non-default vstate_ctrl by making explicit PR_RISCV_V_SET_CONTROL prctl() calls. Link: https://lore.kernel.org/all/87cz4048rp.fsf@all.your.base.are.belong.to.us/ Signed-off-by: Andy Chiu Reviewed-by: Greentime Hu Reviewed-by: Vincent Chen Reviewed-by: Björn Töpel Link: https://lore.kernel.org/r/20230605110724.21391-23-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/vector.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-) (limited to 'arch/riscv') diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c index a7dec9230164..f9c8e19ab301 100644 --- a/arch/riscv/kernel/vector.c +++ b/arch/riscv/kernel/vector.c @@ -180,7 +180,7 @@ void riscv_v_vstate_ctrl_init(struct task_struct *tsk) next = riscv_v_ctrl_get_next(tsk); if (!next) { - if (riscv_v_implicit_uacc) + if (READ_ONCE(riscv_v_implicit_uacc)) cur = PR_RISCV_V_VSTATE_CTRL_ON; else cur = PR_RISCV_V_VSTATE_CTRL_OFF; @@ -243,3 +243,34 @@ long riscv_v_vstate_ctrl_set_current(unsigned long arg) return -EINVAL; } + +#ifdef CONFIG_SYSCTL + +static struct ctl_table riscv_v_default_vstate_table[] = { + { + .procname = "riscv_v_default_allow", + .data = &riscv_v_implicit_uacc, + .maxlen = sizeof(riscv_v_implicit_uacc), + .mode = 0644, + .proc_handler = proc_dobool, + }, + { } +}; + +static int __init riscv_v_sysctl_init(void) +{ + if (has_vector()) + if (!register_sysctl("abi", riscv_v_default_vstate_table)) + return -EINVAL; + return 0; +} + +#else /* ! CONFIG_SYSCTL */ +static int __init riscv_v_sysctl_init(void) { return 0; } +#endif /* ! CONFIG_SYSCTL */ + +static int riscv_v_init(void) +{ + return riscv_v_sysctl_init(); +} +core_initcall(riscv_v_init); -- cgit v1.2.3 From e4bb020f3dbb83912eb6799a9d4bb79da4fd77ec Mon Sep 17 00:00:00 2001 From: Andy Chiu Date: Mon, 5 Jun 2023 11:07:20 +0000 Subject: riscv: detect assembler support for .option arch Some extensions use .option arch directive to selectively enable certain extensions in parts of its assembly code. For example, Zbb uses it to inform assmebler to emit bit manipulation instructions. However, supporting of this directive only exist on GNU assembler and has not landed on clang at the moment, making TOOLCHAIN_HAS_ZBB depend on AS_IS_GNU. While it is still under review at https://reviews.llvm.org/D123515, the upcoming Vector patch also requires this feature in assembler. Thus, provide Kconfig AS_HAS_OPTION_ARCH to detect such feature. Then TOOLCHAIN_HAS_XXX will be turned on automatically when the feature land. Suggested-by: Nathan Chancellor Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Nathan Chancellor Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230605110724.21391-24-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'arch/riscv') diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 348c0fa1fc8c..1019b519d590 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -262,6 +262,12 @@ config RISCV_DMA_NONCOHERENT config AS_HAS_INSN def_bool $(as-instr,.insn r 51$(comma) 0$(comma) 0$(comma) t0$(comma) t0$(comma) zero) +config AS_HAS_OPTION_ARCH + # https://reviews.llvm.org/D123515 + def_bool y + depends on $(as-instr, .option arch$(comma) +m) + depends on !$(as-instr, .option arch$(comma) -i) + source "arch/riscv/Kconfig.socs" source "arch/riscv/Kconfig.errata" @@ -466,7 +472,7 @@ config TOOLCHAIN_HAS_ZBB depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64ima_zbb) depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32ima_zbb) depends on LLD_VERSION >= 150000 || LD_VERSION >= 23900 - depends on AS_IS_GNU + depends on AS_HAS_OPTION_ARCH config RISCV_ISA_ZBB bool "Zbb extension support for bit manipulation instructions" -- cgit v1.2.3 From fa8e7cce55da3569259dc270801885c420eb50fe Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Mon, 5 Jun 2023 11:07:21 +0000 Subject: riscv: Enable Vector code to be built This patch adds configs for building Vector code. First it detects the reqired toolchain support for building the code. Then it provides an option setting whether Vector is implicitly enabled to userspace. Signed-off-by: Guo Ren Co-developed-by: Greentime Hu Signed-off-by: Greentime Hu Co-developed-by: Andy Chiu Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230605110724.21391-25-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 31 +++++++++++++++++++++++++++++++ arch/riscv/Makefile | 6 +++++- 2 files changed, 36 insertions(+), 1 deletion(-) (limited to 'arch/riscv') diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 1019b519d590..f3ba0a8b085e 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -466,6 +466,37 @@ config RISCV_ISA_SVPBMT If you don't know what to do here, say Y. +config TOOLCHAIN_HAS_V + bool + default y + depends on !64BIT || $(cc-option,-mabi=lp64 -march=rv64iv) + depends on !32BIT || $(cc-option,-mabi=ilp32 -march=rv32iv) + depends on LLD_VERSION >= 140000 || LD_VERSION >= 23800 + depends on AS_HAS_OPTION_ARCH + +config RISCV_ISA_V + bool "VECTOR extension support" + depends on TOOLCHAIN_HAS_V + depends on FPU + select DYNAMIC_SIGFRAME + default y + help + Say N here if you want to disable all vector related procedure + in the kernel. + + If you don't know what to do here, say Y. + +config RISCV_ISA_V_DEFAULT_ENABLE + bool "Enable userspace Vector by default" + depends on RISCV_ISA_V + default y + help + Say Y here if you want to enable Vector in userspace by default. + Otherwise, userspace has to make explicit prctl() call to enable + Vector, or enable it via the sysctl interface. + + If you don't know what to do here, say Y. + config TOOLCHAIN_HAS_ZBB bool default y diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile index 0fb256bf8270..6ec6d52a4180 100644 --- a/arch/riscv/Makefile +++ b/arch/riscv/Makefile @@ -60,6 +60,7 @@ riscv-march-$(CONFIG_ARCH_RV32I) := rv32ima riscv-march-$(CONFIG_ARCH_RV64I) := rv64ima riscv-march-$(CONFIG_FPU) := $(riscv-march-y)fd riscv-march-$(CONFIG_RISCV_ISA_C) := $(riscv-march-y)c +riscv-march-$(CONFIG_RISCV_ISA_V) := $(riscv-march-y)v ifdef CONFIG_TOOLCHAIN_NEEDS_OLD_ISA_SPEC KBUILD_CFLAGS += -Wa,-misa-spec=2.2 @@ -71,7 +72,10 @@ endif # Check if the toolchain supports Zihintpause extension riscv-march-$(CONFIG_TOOLCHAIN_HAS_ZIHINTPAUSE) := $(riscv-march-y)_zihintpause -KBUILD_CFLAGS += -march=$(subst fd,,$(riscv-march-y)) +# Remove F,D,V from isa string for all. Keep extensions between "fd" and "v" by +# matching non-v and non-multi-letter extensions out with the filter ([^v_]*) +KBUILD_CFLAGS += -march=$(shell echo $(riscv-march-y) | sed -E 's/(rv32ima|rv64ima)fd([^v_]*)v?/\1\2/') + KBUILD_AFLAGS += -march=$(riscv-march-y) KBUILD_CFLAGS += -mno-save-restore -- cgit v1.2.3