Merge tag 'riscv-for-linus-6.2-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull RISC-V updates from Palmer Dabbelt:

 - Support for the T-Head PMU via the perf subsystem

 - ftrace support for rv32

 - Support for non-volatile memory devices

 - Various fixes and cleanups

* tag 'riscv-for-linus-6.2-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (52 commits)
  Documentation: RISC-V: patch-acceptance: s/implementor/implementer
  Documentation: RISC-V: Mention the UEFI Standards
  Documentation: RISC-V: Allow patches for non-standard behavior
  Documentation: RISC-V: Fix a typo in patch-acceptance
  riscv: Fixup compile error with !MMU
  riscv: Fix P4D_SHIFT definition for 3-level page table mode
  riscv: Apply a static assert to riscv_isa_ext_id
  RISC-V: Add some comments about the shadow and overflow stacks
  RISC-V: Align the shadow stack
  RISC-V: Ensure Zicbom has a valid block size
  RISC-V: Introduce riscv_isa_extension_check
  RISC-V: Improve use of isa2hwcap[]
  riscv: Don't duplicate _ALTERNATIVE_CFG* macros
  riscv: alternatives: Drop the underscores from the assembly macro names
  riscv: alternatives: Don't name unused macro parameters
  riscv: Don't duplicate __ALTERNATIVE_CFG in __ALTERNATIVE_CFG_2
  riscv: mm: call best_map_size many times during linear-mapping
  riscv: Move cast inside kernel_mapping_[pv]a_to_[vp]a
  riscv: Fix crash during early errata patching
  riscv: boot: add zstd support
  ...

1 files changed, 93 insertions, 0 deletions

diff --git a/arch/riscv/kernel/probes/rethook_trampoline.S b/arch/riscv/kernel/probes/rethook_trampoline.S
new file mode 100644
index 000000000000..21bac92a170a
--- /dev/null
+++ b/arch/riscv/kernel/probes/rethook_trampoline.S
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Author: Patrick Stählin <me@packi.ch>
+ */
+#include <linux/linkage.h>
+
+#include <asm/asm.h>
+#include <asm/asm-offsets.h>
+
+	.text
+	.altmacro
+
+	.macro save_all_base_regs
+	REG_S x1,  PT_RA(sp)
+	REG_S x3,  PT_GP(sp)
+	REG_S x4,  PT_TP(sp)
+	REG_S x5,  PT_T0(sp)
+	REG_S x6,  PT_T1(sp)
+	REG_S x7,  PT_T2(sp)
+	REG_S x8,  PT_S0(sp)
+	REG_S x9,  PT_S1(sp)
+	REG_S x10, PT_A0(sp)
+	REG_S x11, PT_A1(sp)
+	REG_S x12, PT_A2(sp)
+	REG_S x13, PT_A3(sp)
+	REG_S x14, PT_A4(sp)
+	REG_S x15, PT_A5(sp)
+	REG_S x16, PT_A6(sp)
+	REG_S x17, PT_A7(sp)
+	REG_S x18, PT_S2(sp)
+	REG_S x19, PT_S3(sp)
+	REG_S x20, PT_S4(sp)
+	REG_S x21, PT_S5(sp)
+	REG_S x22, PT_S6(sp)
+	REG_S x23, PT_S7(sp)
+	REG_S x24, PT_S8(sp)
+	REG_S x25, PT_S9(sp)
+	REG_S x26, PT_S10(sp)
+	REG_S x27, PT_S11(sp)
+	REG_S x28, PT_T3(sp)
+	REG_S x29, PT_T4(sp)
+	REG_S x30, PT_T5(sp)
+	REG_S x31, PT_T6(sp)
+	.endm
+
+	.macro restore_all_base_regs
+	REG_L x3,  PT_GP(sp)
+	REG_L x4,  PT_TP(sp)
+	REG_L x5,  PT_T0(sp)
+	REG_L x6,  PT_T1(sp)
+	REG_L x7,  PT_T2(sp)
+	REG_L x8,  PT_S0(sp)
+	REG_L x9,  PT_S1(sp)
+	REG_L x10, PT_A0(sp)
+	REG_L x11, PT_A1(sp)
+	REG_L x12, PT_A2(sp)
+	REG_L x13, PT_A3(sp)
+	REG_L x14, PT_A4(sp)
+	REG_L x15, PT_A5(sp)
+	REG_L x16, PT_A6(sp)
+	REG_L x17, PT_A7(sp)
+	REG_L x18, PT_S2(sp)
+	REG_L x19, PT_S3(sp)
+	REG_L x20, PT_S4(sp)
+	REG_L x21, PT_S5(sp)
+	REG_L x22, PT_S6(sp)
+	REG_L x23, PT_S7(sp)
+	REG_L x24, PT_S8(sp)
+	REG_L x25, PT_S9(sp)
+	REG_L x26, PT_S10(sp)
+	REG_L x27, PT_S11(sp)
+	REG_L x28, PT_T3(sp)
+	REG_L x29, PT_T4(sp)
+	REG_L x30, PT_T5(sp)
+	REG_L x31, PT_T6(sp)
+	.endm
+
+ENTRY(arch_rethook_trampoline)
+	addi sp, sp, -(PT_SIZE_ON_STACK)
+	save_all_base_regs
+
+	move a0, sp /* pt_regs */
+
+	call arch_rethook_trampoline_callback
+
+	/* use the result as the return-address */
+	move ra, a0
+
+	restore_all_base_regs
+	addi sp, sp, PT_SIZE_ON_STACK
+
+	ret
+ENDPROC(arch_rethook_trampoline)