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Nathan Chancellor <nathan@kernel.org> says:
This series disables DWARF5 for LLVM versions where it is known to be
broken due to linker relaxation.
* b4-shazam-merge:
lib/Kconfig.debug: Update AS_HAS_NON_CONST_LEB128 comment and name
riscv: Restrict DWARF5 when building with LLVM to known working versions
riscv: Hoist linker relaxation disabling logic into Kconfig
Link: https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6
Link: https://lore.kernel.org/r/20231205-riscv-restrict-dwarf5-llvm-v2-0-aedf00a382ac@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Fangrui noted that the comment around CONFIG_AS_HAS_NON_CONST_LEB128
could be made more accurate because explicit .sleb128 directives are not
emitted, only .uleb128 directives are. Rename the symbol to
CONFIG_AS_HAS_NON_CONST_ULEB128 as a result.
Further clarifications include replacing "symbol deltas" with the more
accurate "label differences", noting that this issue has been resolved
in newer binutils (2.41+), and it only occurs when a port uses RISC-V
style linker relaxation.
Suggested-by: Fangrui Song <maskray@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231205-riscv-restrict-dwarf5-llvm-v2-3-aedf00a382ac@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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LLVM prior to 18.0.0 would generate incorrect debug info for DWARF5 due
to linker relaxation, which was worked around in clang by defaulting
RISC-V to DWARF4 [1]. Unfortunately, this workaround does not work for
the kernel because the DWARF version can be independently changed from
the default in Kconfig.
Do not allow DWARF5 to be selected for RISC-V when using linker
relaxation (ld.lld >= 15.0.0) and a version of LLVM that does not have
the fixes (the integrated assembler [2] and ld.lld [3] < 18.0.0)
necessary to generate the correct debug info.
Link: https://github.com/llvm/llvm-project/commit/bbc0f99f3bc96f1db16f649fc21dd18e5b0918f6 [1]
Link: https://github.com/llvm/llvm-project/commit/1df5ea29b43690b6622db2cad7b745607ca4de6a [2]
Link: https://github.com/llvm/llvm-project/commit/7ffabb61a5569444b5ac9322e22e5471cc5e4a77 [3]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Fangrui Song <maskray@google.com>
Link: https://lore.kernel.org/r/20231205-riscv-restrict-dwarf5-llvm-v2-2-aedf00a382ac@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Certain configurations may need to be disabled if linker relaxation is
in use, such as DWARF5 with ld.lld < 18. Hoist the logic of whether or
not linker relaxation is in use into Kconfig so decisions can be made at
configuration time.
Reviewed-by: Fangrui Song <maskray@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20231205-riscv-restrict-dwarf5-llvm-v2-1-aedf00a382ac@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Charlie Jenkins <charlie@rivosinc.com> says:
Each architecture generally implements fine-tuned checksum functions to
leverage the instruction set. This patch adds the main checksum
functions that are used in networking. Tested on QEMU, this series
allows the CHECKSUM_KUNIT tests to complete an average of 50.9% faster.
This patch takes heavy use of the Zbb extension using alternatives
patching.
To test this patch, enable the configs for KUNIT, then CHECKSUM_KUNIT.
I have attempted to make these functions as optimal as possible, but I
have not ran anything on actual riscv hardware. My performance testing
has been limited to inspecting the assembly, running the algorithms on
x86 hardware, and running in QEMU.
ip_fast_csum is a relatively small function so even though it is
possible to read 64 bits at a time on compatible hardware, the
bottleneck becomes the clean up and setup code so loading 32 bits at a
time is actually faster.
* b4-shazam-merge:
kunit: Add tests for csum_ipv6_magic and ip_fast_csum
riscv: Add checksum library
riscv: Add checksum header
riscv: Add static key for misaligned accesses
asm-generic: Improve csum_fold
Link: https://lore.kernel.org/r/20240108-optimize_checksum-v15-0-1c50de5f2167@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Supplement existing checksum tests with tests for csum_ipv6_magic and
ip_fast_csum.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20240108-optimize_checksum-v15-5-1c50de5f2167@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Provide a 32 and 64 bit version of do_csum. When compiled for 32-bit
will load from the buffer in groups of 32 bits, and when compiled for
64-bit will load in groups of 64 bits.
Additionally provide riscv optimized implementation of csum_ipv6_magic.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Xiao Wang <xiao.w.wang@intel.com>
Link: https://lore.kernel.org/r/20240108-optimize_checksum-v15-4-1c50de5f2167@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Provide checksum algorithms that have been designed to leverage riscv
instructions such as rotate. In 64-bit, can take advantage of the larger
register to avoid some overflow checking.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Xiao Wang <xiao.w.wang@intel.com>
Link: https://lore.kernel.org/r/20240108-optimize_checksum-v15-3-1c50de5f2167@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Support static branches depending on the value of misaligned accesses.
This will be used by a later patch in the series. At any point in time,
this static branch will only be enabled if all online CPUs are
considered "fast".
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Evan Green <evan@rivosinc.com>
Link: https://lore.kernel.org/r/20240108-optimize_checksum-v15-2-1c50de5f2167@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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This csum_fold implementation introduced into arch/arc by Vineet Gupta
is better than the default implementation on at least arc, x86, and
riscv. Using GCC trunk and compiling non-inlined version, this
implementation has 41.6667%, 25% fewer instructions on riscv64, x86-64
respectively with -O3 optimization. Most implmentations override this
default in asm, but this should be more performant than all of those
other implementations except for arm which has barrel shifting and
sparc32 which has a carry flag.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: David Laight <david.laight@aculab.com>
Link: https://lore.kernel.org/r/20240108-optimize_checksum-v15-1-1c50de5f2167@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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The 'i' constraint expects a constant operand, which fn and its
constant derivative MK_CBO(fn) are, but passing fn through a function
as a parameter and using a local variable for MK_CBO(fn) allow the
compiler to lose sight of that when no optimization is done. Use
a macro instead of a function and skip the local variable to ensure
the compiler uses constants, matching the asm constraints.
Reported-by: Yunhui Cui <cuiyunhui@bytedance.com>
Closes: https://lore.kernel.org/all/20240117082514.42967-1-cuiyunhui@bytedance.com
Fixes: a29e2a48afe3 ("RISC-V: selftests: Add CBO tests")
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20240117130933.57514-2-ajones@ventanamicro.com
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Andy Chiu <andy.chiu@sifive.com> says:
This series provides support running Vector in kernel mode.
Additionally, kernel-mode Vector can be configured to run without
turnning off preemption on a CONFIG_PREEMPT kernel. Along with the
suport, we add Vector optimized copy_{to,from}_user. And provide a
simple threshold to decide when to run the vectorized functions.
We decided to drop vectorized memcpy/memset/memmove for the moment due
to the concern of memory side-effect in kernel_vector_begin(). The
detailed description can be found at v9[0]
This series is composed by 4 parts:
patch 1-4: adds basic support for kernel-mode Vector
patch 5: includes vectorized copy_{to,from}_user into the kernel
patch 6: refactor context switch code in fpu [1]
patch 7-10: provides some code refactors and support for preemptible
kernel-mode Vector.
This series can be merged if we feel any part of {1~4, 5, 6, 7~10} is
mature enough.
This patch is tested on a QEMU with V and verified that booting, normal
userspace operations all work as usual with thresholds set to 0. Also,
we test by launching multiple kernel threads which continuously executes
and verifies Vector operations in the background. The module that tests
these operation is expected to be upstream later.
* b4-shazam-merge:
riscv: vector: allow kernel-mode Vector with preemption
riscv: vector: use kmem_cache to manage vector context
riscv: vector: use a mask to write vstate_ctrl
riscv: vector: do not pass task_struct into riscv_v_vstate_{save,restore}()
riscv: fpu: drop SR_SD bit checking
riscv: lib: vectorize copy_to_user/copy_from_user
riscv: sched: defer restoring Vector context for user
riscv: Add vector extension XOR implementation
riscv: vector: make Vector always available for softirq context
riscv: Add support for kernel mode vector
Link: https://lore.kernel.org/r/20240115055929.4736-1-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Add kernel_vstate to keep track of kernel-mode Vector registers when
trap introduced context switch happens. Also, provide riscv_v_flags to
let context save/restore routine track context status. Context tracking
happens whenever the core starts its in-kernel Vector executions. An
active (dirty) kernel task's V contexts will be saved to memory whenever
a trap-introduced context switch happens. Or, when a softirq, which
happens to nest on top of it, uses Vector. Context retoring happens when
the execution transfer back to the original Kernel context where it
first enable preempt_v.
Also, provide a config CONFIG_RISCV_ISA_V_PREEMPTIVE to give users an
option to disable preemptible kernel-mode Vector at build time. Users
with constraint memory may want to disable this config as preemptible
kernel-mode Vector needs extra space for tracking of per thread's
kernel-mode V context. Or, users might as well want to disable it if all
kernel-mode Vector code is time sensitive and cannot tolerate context
switch overhead.
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-11-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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The allocation size of thread.vstate.datap is always riscv_v_vsize. So
it is possbile to use kmem_cache_* to manage the allocation. This gives
users more information regarding allocation of vector context via
/proc/slabinfo. And it potentially reduces the latency of the first-use
trap because of the allocation caches.
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-10-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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riscv_v_ctrl_set() should only touch bits within
PR_RISCV_V_VSTATE_CTRL_MASK. So, use the mask when we really set task's
vstate_ctrl.
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-9-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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riscv_v_vstate_{save,restore}() can operate only on the knowlege of
struct __riscv_v_ext_state, and struct pt_regs. Let the caller decides
which should be passed into the function. Meanwhile, the kernel-mode
Vector is going to introduce another vstate, so this also makes functions
potentially able to be reused.
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-8-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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SR_SD summarizes the dirty status of FS/VS/XS. However, the current code
structure does not fully utilize it because each extension specific code
is divided into an individual segment. So remove the SR_SD check for
now.
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Song Shuai <songshuaishuai@tinylab.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-7-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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This patch utilizes Vector to perform copy_to_user/copy_from_user. If
Vector is available and the size of copy is large enough for Vector to
perform better than scalar, then direct the kernel to do Vector copies
for userspace. Though the best programming practice for users is to
reduce the copy, this provides a faster variant when copies are
inevitable.
The optimal size for using Vector, copy_to_user_thres, is only a
heuristic for now. We can add DT parsing if people feel the need of
customizing it.
The exception fixup code of the __asm_vector_usercopy must fallback to
the scalar one because accessing user pages might fault, and must be
sleepable. Current kernel-mode Vector does not allow tasks to be
preemptible, so we must disactivate Vector and perform a scalar fallback
in such case.
The original implementation of Vector operations comes from
https://github.com/sifive/sifive-libc, which we agree to contribute to
Linux kernel.
Co-developed-by: Jerry Shih <jerry.shih@sifive.com>
Signed-off-by: Jerry Shih <jerry.shih@sifive.com>
Co-developed-by: Nick Knight <nick.knight@sifive.com>
Signed-off-by: Nick Knight <nick.knight@sifive.com>
Suggested-by: Guo Ren <guoren@kernel.org>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-6-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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User will use its Vector registers only after the kernel really returns
to the userspace. So we can delay restoring Vector registers as long as
we are still running in kernel mode. So, add a thread flag to indicates
the need of restoring Vector and do the restore at the last
arch-specific exit-to-user hook. This save the context restoring cost
when we switch over multiple processes that run V in kernel mode. For
example, if the kernel performs a context swicth from A->B->C, and
returns to C's userspace, then there is no need to restore B's
V-register.
Besides, this also prevents us from repeatedly restoring V context when
executing kernel-mode Vector multiple times.
The cost of this is that we must disable preemption and mark vector as
busy during vstate_{save,restore}. Because then the V context will not
get restored back immediately when a trap-causing context switch happens
in the middle of vstate_{save,restore}.
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-5-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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This patch adds support for vector optimized XOR and it is tested in
qemu.
Co-developed-by: Han-Kuan Chen <hankuan.chen@sifive.com>
Signed-off-by: Han-Kuan Chen <hankuan.chen@sifive.com>
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-4-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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The goal of this patch is to provide full support of Vector in kernel
softirq context. So that some of the crypto alogrithms won't need scalar
fallbacks.
By disabling bottom halves in active kernel-mode Vector, softirq will
not be able to nest on top of any kernel-mode Vector. So, softirq
context is able to use Vector whenever it runs.
After this patch, Vector context cannot start with irqs disabled.
Otherwise local_bh_enable() may run in a wrong context.
Disabling bh is not enough for RT-kernel to prevent preeemption. So
we must disable preemption, which also implies disabling bh on RT.
Related-to: commit 696207d4258b ("arm64/sve: Make kernel FPU protection RT friendly")
Related-to: commit 66c3ec5a7120 ("arm64: neon: Forbid when irqs are disabled")
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-3-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Add kernel_vector_begin() and kernel_vector_end() function declarations
and corresponding definitions in kernel_mode_vector.c
These are needed to wrap uses of vector in kernel mode.
Co-developed-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-2-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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guoren@kernel.org <guoren@kernel.org> says:
From: Guo Ren <guoren@linux.alibaba.com>
When the task is in COMPAT mode, the TASK_SIZE should be 2GB, so
STACK_TOP_MAX and arch_get_mmap_end must be limited to 2 GB. This series
fixes the problem made by commit: add2cc6b6515 ("RISC-V: mm: Restrict
address space for sv39,sv48,sv57") and optimizes the related coding
convention of TASK_SIZE.
* b4-shazam-merge:
riscv: mm: Fixup compat arch_get_mmap_end
riscv: mm: Fixup compat mode boot failure
Link: https://lore.kernel.org/r/20231222115703.2404036-1-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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When the task is in COMPAT mode, the arch_get_mmap_end should be 2GB,
not TASK_SIZE_64. The TASK_SIZE has contained is_compat_mode()
detection, so change the definition of STACK_TOP_MAX to TASK_SIZE
directly.
Cc: stable@vger.kernel.org
Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231222115703.2404036-3-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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In COMPAT mode, the STACK_TOP is DEFAULT_MAP_WINDOW (0x80000000), but
the TASK_SIZE is 0x7fff000. When the user stack is upon 0x7fff000, it
will cause a user segment fault. Sometimes, it would cause boot
failure when the whole rootfs is rv32.
Freeing unused kernel image (initmem) memory: 2236K
Run /sbin/init as init process
Starting init: /sbin/init exists but couldn't execute it (error -14)
Run /etc/init as init process
...
Increase the TASK_SIZE to cover STACK_TOP.
Cc: stable@vger.kernel.org
Fixes: add2cc6b6515 ("RISC-V: mm: Restrict address space for sv39,sv48,sv57")
Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Signed-off-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20231222115703.2404036-2-guoren@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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The ending NULL is not taken into account by strncat(), so switch to
strlcat() to correctly compute the size of the available memory when
appending CONFIG_CMDLINE to 'early_cmdline'.
Fixes: 26e7aacb83df ("riscv: Allow to downgrade paging mode from the command line")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/9f66d2b58c8052d4055e90b8477ee55d9a0914f9.1698564026.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Christoph Muellner <christoph.muellner@vrull.eu> says:
From: Christoph Müllner <christoph.muellner@vrull.eu>
When building the RISC-V selftests with a riscv32 compiler I ran into
a couple of compiler warnings. While riscv32 support for these tests is
questionable, the fixes are so trivial that it is probably best to simply
apply them.
Note that the missing-include patch and some format string warnings
are also relevant for riscv64.
* b4-shazam-merge:
tools: selftests: riscv: Fix compile warnings in mm tests
tools: selftests: riscv: Fix compile warnings in vector tests
tools: selftests: riscv: Add missing include for vector test
tools: selftests: riscv: Fix compile warnings in cbo
tools: selftests: riscv: Fix compile warnings in hwprobe
Link: https://lore.kernel.org/r/20231123185821.2272504-1-christoph.muellner@vrull.eu
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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When building the mm tests with a riscv32 compiler, we see a range
of shift-count-overflow errors from shifting 1UL by more than 32 bits
in do_mmaps(). Since, the relevant code is only called from code that
is gated by `__riscv_xlen == 64`, we can just apply the same gating
to do_mmaps().
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231123185821.2272504-6-christoph.muellner@vrull.eu
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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GCC prints a couple of format string warnings when compiling
the vector tests. Let's follow the recommendation in
Documentation/printk-formats.txt to fix these warnings.
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231123185821.2272504-5-christoph.muellner@vrull.eu
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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GCC raises the following warning:
warning: 'status' may be used uninitialized
The warning comes from the fact, that the signature of waitpid() is
unknown and therefore the initialization of GCC cannot be guessed.
Let's add the relevant header to address this warning.
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231123185821.2272504-4-christoph.muellner@vrull.eu
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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GCC prints a couple of format string warnings when compiling
the cbo test. Let's follow the recommendation in
Documentation/printk-formats.txt to fix these warnings.
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231123185821.2272504-3-christoph.muellner@vrull.eu
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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GCC prints a couple of format string warnings when compiling
the hwprobe test. Let's follow the recommendation in
Documentation/printk-formats.txt to fix these warnings.
Signed-off-by: Christoph Müllner <christoph.muellner@vrull.eu>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231123185821.2272504-2-christoph.muellner@vrull.eu
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Allow to defer the flushing of the TLB when unmapping pages, which allows
to reduce the numbers of IPI and the number of sfence.vma.
The ubenchmarch used in commit 43b3dfdd0455 ("arm64: support
batched/deferred tlb shootdown during page reclamation/migration") that
was multithreaded to force the usage of IPI shows good performance
improvement on all platforms:
* Unmatched: ~34%
* TH1520 : ~78%
* Qemu : ~81%
In addition, perf on qemu reports an important decrease in time spent
dealing with IPIs:
Before: 68.17% main [kernel.kallsyms] [k] __sbi_rfence_v02_call
After : 8.64% main [kernel.kallsyms] [k] __sbi_rfence_v02_call
* Benchmark:
int stick_this_thread_to_core(int core_id) {
int num_cores = sysconf(_SC_NPROCESSORS_ONLN);
if (core_id < 0 || core_id >= num_cores)
return EINVAL;
cpu_set_t cpuset;
CPU_ZERO(&cpuset);
CPU_SET(core_id, &cpuset);
pthread_t current_thread = pthread_self();
return pthread_setaffinity_np(current_thread,
sizeof(cpu_set_t), &cpuset);
}
static void *fn_thread (void *p_data)
{
int ret;
pthread_t thread;
stick_this_thread_to_core((int)p_data);
while (1) {
sleep(1);
}
return NULL;
}
int main()
{
volatile unsigned char *p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, -1, 0);
pthread_t threads[4];
int ret;
for (int i = 0; i < 4; ++i) {
ret = pthread_create(&threads[i], NULL, fn_thread, (void *)i);
if (ret)
{
printf("%s", strerror (ret));
}
}
memset(p, 0x88, SIZE);
for (int k = 0; k < 10000; k++) {
/* swap in */
for (int i = 0; i < SIZE; i += 4096) {
(void)p[i];
}
/* swap out */
madvise(p, SIZE, MADV_PAGEOUT);
}
for (int i = 0; i < 4; i++)
{
pthread_cancel(threads[i]);
}
for (int i = 0; i < 4; i++)
{
pthread_join(threads[i], NULL);
}
return 0;
}
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Jisheng Zhang <jszhang@kernel.org> # Tested on TH1520
Tested-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20240108193640.344929-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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This will allow better TLB utilization and then should be more performant.
Before:
---[ vmemmap start ]---
0xffff8d8002000000-0xffff8d8012000000 0x000000046ec00000 256M PTE . .. .. D A G . . W R V
---[ vmemmap end ]---
After:
---[ vmemmap start ]---
0xffff8d8002000000-0xffff8d8012000000 0x000000046ec00000 256M PMD . .. .. D A G . . W R V
---[ vmemmap end ]---
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Link: https://lore.kernel.org/r/20231214132935.212864-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Following the examples of cbom-block-size and cboz-block-size,
cbop-block-size is the cache size of Zicbop (cbo.prefetch) operations.
The most common case is to have all cache block sizes to be the same
size (e.g. profiles such as rva22u64 mandates a 64 bytes size for all
cache operations), but there's no specification requirement for that,
and an implementation can have different cache sizes for each operation.
Cc: Rob Herring <robh@kernel.org>
Cc: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231029123500.739409-1-dbarboza@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jisheng Zhang <jszhang@kernel.org> says:
Previously, we use alternative mechanism to dynamically patch
the CMO operations for THEAD C906/C910 during boot for performance
reason. But as pointed out by Arnd, "there is already a significant
cost in accessing the invalidated cache lines afterwards, which is
likely going to be much higher than the cost of an indirect branch".
And indeed, there's no performance difference with GMAC and EMMC per
my test on Sipeed Lichee Pi 4A board.
Use riscv_nonstd_cache_ops for THEAD C906/C910 CMO to simplify
the alternative code, and to acchieve Arnd's goal -- "I think
moving the THEAD ops at the same level as all nonstandard operations
makes sense, but I'd still leave CMO as an explicit fast path that
avoids the indirect branch. This seems like the right thing to do both
for readability and for platforms on which the indirect branch has a
noticeable overhead."
To make bisect easy, I use two patches here: patch1 does the conversion
which just mimics current CMO behavior via. riscv_nonstd_cache_ops, I
assume no functionalities changes. patch2 uses T-HEAD PA based CMO
instructions so that we don't need to covert PA to VA.
* b4-shazam-merge:
riscv: errata: thead: use pa based instructions for CMO
riscv: errata: thead: use riscv_nonstd_cache_ops for CMO
Link: https://lore.kernel.org/r/20231114143338.2406-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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There are some extensions that contain numbers, such as Zve32f, which
are enabled by the "max" cpu type in QEMU.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20231208-uncolored-oxidant-5ab37dd3ab84@spud
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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The current description implies that only a single address translation
mode is available to the operating system. However, some implementations
support multiple address translation modes, and the operating system is
free to choose between them.
Per the RISC-V privileged specification, Sv48 implementations must also
implement Sv39, and likewise Sv57 implies support for Sv48. This means
it is possible to describe all supported address translation modes using
a single value, by naming the largest supported mode. This appears to
have been the intended usage of the property, so note it explicitly.
Fixes: 4fd669a8c487 ("dt-bindings: riscv: convert cpu binding to json-schema")
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20231227175739.1453782-1-samuel.holland@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Anup Patel <apatel@ventanamicro.com> says:
The SBI v2.0 specification is now frozen. The SBI v2.0 specification defines
SBI debug console (DBCN) extension which replaces the legacy SBI v0.1
functions sbi_console_putchar() and sbi_console_getchar().
(Refer v2.0-rc5 at https://github.com/riscv-non-isa/riscv-sbi-doc/releases)
This series adds support for SBI debug console (DBCN) extension in
Linux RISC-V.
To try these patches with KVM RISC-V, use KVMTOOL from the
riscv_zbx_zicntr_smstateen_condops_v1 branch at:
https://github.com/avpatel/kvmtool.git
* b4-shazam-merge:
RISC-V: Enable SBI based earlycon support
tty: Add SBI debug console support to HVC SBI driver
tty/serial: Add RISC-V SBI debug console based earlycon
RISC-V: Add SBI debug console helper routines
RISC-V: Add stubs for sbi_console_putchar/getchar()
Link: https://lore.kernel.org/r/20231124070905.1043092-1-apatel@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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When the SUSP SBI extension is present it implies that the standard
"suspend to RAM" type is available. Wire it up to the generic
platform suspend support, also applying the already present support
for non-retentive CPU suspend. When the kernel is built with
CONFIG_SUSPEND, one can do 'echo mem > /sys/power/state' to suspend.
Resumption will occur when a platform-specific wake-up event arrives.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20231206110807.35882-4-ajones@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Charlie Jenkins <charlie@rivosinc.com> says:
When modules are loaded while there is not ample allocatable memory,
there was previously not proper error handling. This series fixes a
use-after-free error and a different issue that caused a non graceful
exit after memory was not properly allocated.
* b4-shazam-merge:
riscv: Fix relocation_hashtable size
riscv: Correctly free relocation hashtable on error
riscv: Fix module loading free order
Link: https://lore.kernel.org/r/20240104-module_loading_fix-v3-0-a71f8de6ce0f@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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DCACHE_WORD_ACCESS"
Jisheng Zhang <jszhang@kernel.org> says:
Some riscv implementations such as T-HEAD's C906, C908, C910 and C920
support efficient unaligned access, for performance reason we want
to enable HAVE_EFFICIENT_UNALIGNED_ACCESS on these platforms. To
avoid performance regressions on non efficient unaligned access
platforms, HAVE_EFFICIENT_UNALIGNED_ACCESS can't be globally selected.
To solve this problem, runtime code patching based on the detected
speed is a good solution. But that's not easy, it involves lots of
work to modify vairous subsystems such as net, mm, lib and so on.
This can be done step by step.
So let's take an easier solution: add support to efficient unaligned
access and hide the support under NONPORTABLE.
patch1 introduces RISCV_EFFICIENT_UNALIGNED_ACCESS which depends on
NONPORTABLE, if users know during config time that the kernel will be
only run on those efficient unaligned access hw platforms, they can
enable it. Obviously, generic unified kernel Image shouldn't enable it.
patch2 adds support DCACHE_WORD_ACCESS when MMU and
RISCV_EFFICIENT_UNALIGNED_ACCESS.
Below test program and step shows how much performance can be improved:
$ cat tt.c
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#define ITERATIONS 1000000
#define PATH "123456781234567812345678123456781"
int main(void)
{
unsigned long i;
struct stat buf;
for (i = 0; i < ITERATIONS; i++)
stat(PATH, &buf);
return 0;
}
$ gcc -O2 tt.c
$ touch 123456781234567812345678123456781
$ time ./a.out
Per my test on T-HEAD C910 platforms, the above test performance is
improved by about 7.5%.
* b4-shazam-merge:
riscv: select DCACHE_WORD_ACCESS for efficient unaligned access HW
riscv: introduce RISCV_EFFICIENT_UNALIGNED_ACCESS
Link: https://lore.kernel.org/r/20231225044207.3821-1-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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T-HEAD CPUs such as C906/C910/C920 support phy address based CMO, use
them so that we don't need to convert to virt address.
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Guo Ren <guoren@kernel.org>
Link: https://lore.kernel.org/r/20231114143338.2406-3-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Previously, we use alternative mechanism to dynamically patch
the CMO operations for THEAD C906/C910 during boot for performance
reason. But as pointed out by Arnd, "there is already a significant
cost in accessing the invalidated cache lines afterwards, which is
likely going to be much higher than the cost of an indirect branch".
And indeed, there's no performance difference with GMAC and EMMC per
my test on Sipeed Lichee Pi 4A board.
Use riscv_nonstd_cache_ops for THEAD C906/C910 CMO to simplify
the alternative code, and to acchieve Arnd's goal -- "I think
moving the THEAD ops at the same level as all nonstandard operations
makes sense, but I'd still leave CMO as an explicit fast path that
avoids the indirect branch. This seems like the right thing to do both
for readability and for platforms on which the indirect branch has a
noticeable overhead."
Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20231114143338.2406-2-jszhang@kernel.org
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Let us enable SBI based earlycon support in defconfig for both RV32
and RV64 so that "earlycon=sbi" can be used again.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231124070905.1043092-6-apatel@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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RISC-V SBI specification supports advanced debug console
support via SBI DBCN extension.
Extend the HVC SBI driver to support it.
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20231124070905.1043092-5-apatel@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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We extend the existing RISC-V SBI earlycon support to use the new
RISC-V SBI debug console extension.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/r/20231124070905.1043092-4-apatel@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Let us provide SBI debug console helper routines which can be
shared by serial/earlycon-riscv-sbi.c and hvc/hvc_riscv_sbi.c.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231124070905.1043092-3-apatel@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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The functions sbi_console_putchar() and sbi_console_getchar() are
not defined when CONFIG_RISCV_SBI_V01 is disabled so let us add
stub of these functions to avoid "#ifdef" on user side.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20231124070905.1043092-2-apatel@ventanamicro.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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A second dereference is needed to get the accurate size of the
relocation_hashtable.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Fixes: d8792a5734b0 ("riscv: Safely remove entries from relocation list")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Closes: https://lore.kernel.org/r/202312120044.wTI1Uyaa-lkp@intel.com/
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/20240104-module_loading_fix-v3-3-a71f8de6ce0f@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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