- 20 Sep, 2024 7 commits
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Jinjie Ruan authored
On RISCV64 Qemu machine with 512MB memory, cmdline "crashkernel=500M,high" will cause system stall as below: Zone ranges: DMA32 [mem 0x0000000080000000-0x000000009fffffff] Normal empty Movable zone start for each node Early memory node ranges node 0: [mem 0x0000000080000000-0x000000008005ffff] node 0: [mem 0x0000000080060000-0x000000009fffffff] Initmem setup node 0 [mem 0x0000000080000000-0x000000009fffffff] (stall here) commit 5d99cadf1568 ("crash: fix x86_32 crash memory reserve dead loop bug") fix this on 32-bit architecture. However, the problem is not completely solved. If `CRASH_ADDR_LOW_MAX = CRASH_ADDR_HIGH_MAX` on 64-bit architecture, for example, when system memory is equal to CRASH_ADDR_LOW_MAX on RISCV64, the following infinite loop will also occur: -> reserve_crashkernel_generic() and high is true -> alloc at [CRASH_ADDR_LOW_MAX, CRASH_ADDR_HIGH_MAX] fail -> alloc at [0, CRASH_ADDR_LOW_MAX] fail and repeatedly (because CRASH_ADDR_LOW_MAX = CRASH_ADDR_HIGH_MAX). As Catalin suggested, do not remove the ",high" reservation fallback to ",low" logic which will change arm64's kdump behavior, but fix it by skipping the above situation similar to commit d2f32f23190b ("crash: fix x86_32 crash memory reserve dead loop"). After this patch, it print: cannot allocate crashkernel (size:0x1f400000) Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Baoquan He <bhe@redhat.com> Link: https://lore.kernel.org/r/20240812062017.2674441-1-ruanjinjie@huawei.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Mayuresh Chitale authored
The SBI v2.0 specification pointed to by the link below reserves the event code 0xffff for platform specific firmware events. Update the driver to be able to parse and program such events. The platform specific firmware events must now be specified in the perf command as below: perf stat -e rCxxx ... where bits[63:62] = 0x3 of the event config indicate a platform specific firmware event and xxx indicate the actual event code which is passed as the event data. Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com> Link: https://github.com/riscv-non-isa/riscv-sbi-doc/releases/download/v2.0/riscv-sbi.pdf Link: https://lore.kernel.org/r/20240812051109.6496-1-mchitale@ventanamicro.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
Charlie Jenkins <charlie@rivosinc.com> says: Add support for riscv specific barrier implementations to the tools tree, so that fence instructions can be emitted for synchronization. * b4-shazam-merge: tools: Optimize ring buffer for riscv tools: Add riscv barrier implementation Link: https://lore.kernel.org/r/20240806-optimize_ring_buffer_read_riscv-v2-0-ca7e193ae198@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Charlie Jenkins authored
Now that the riscv tools tree supports optimized barriers, use them in the ring buffer. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Andrea Parri <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20240806-optimize_ring_buffer_read_riscv-v2-2-ca7e193ae198@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Charlie Jenkins authored
Many of the other architectures use their custom barrier implementations. Use the barrier code from the kernel sources to optimize barriers in tools. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Andrea Parri <parri.andrea@gmail.com> Link: https://lore.kernel.org/r/20240806-optimize_ring_buffer_read_riscv-v2-1-ca7e193ae198@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
I recently ended up with a warning on some compilers along the lines of CC kernel/resource.o In file included from include/linux/ioport.h:16, from kernel/resource.c:15: kernel/resource.c: In function 'gfr_start': include/linux/minmax.h:49:37: error: conversion from 'long long unsigned int' to 'resource_size_t' {aka 'unsigned int'} changes value from '17179869183' to '4294967295' [-Werror=overflow] 49 | ({ type ux = (x); type uy = (y); __cmp(op, ux, uy); }) | ^ include/linux/minmax.h:52:9: note: in expansion of macro '__cmp_once_unique' 52 | __cmp_once_unique(op, type, x, y, __UNIQUE_ID(x_), __UNIQUE_ID(y_)) | ^~~~~~~~~~~~~~~~~ include/linux/minmax.h:161:27: note: in expansion of macro '__cmp_once' 161 | #define min_t(type, x, y) __cmp_once(min, type, x, y) | ^~~~~~~~~~ kernel/resource.c:1829:23: note: in expansion of macro 'min_t' 1829 | end = min_t(resource_size_t, base->end, | ^~~~~ kernel/resource.c: In function 'gfr_continue': include/linux/minmax.h:49:37: error: conversion from 'long long unsigned int' to 'resource_size_t' {aka 'unsigned int'} changes value from '17179869183' to '4294967295' [-Werror=overflow] 49 | ({ type ux = (x); type uy = (y); __cmp(op, ux, uy); }) | ^ include/linux/minmax.h:52:9: note: in expansion of macro '__cmp_once_unique' 52 | __cmp_once_unique(op, type, x, y, __UNIQUE_ID(x_), __UNIQUE_ID(y_)) | ^~~~~~~~~~~~~~~~~ include/linux/minmax.h:161:27: note: in expansion of macro '__cmp_once' 161 | #define min_t(type, x, y) __cmp_once(min, type, x, y) | ^~~~~~~~~~ kernel/resource.c:1847:24: note: in expansion of macro 'min_t' 1847 | addr <= min_t(resource_size_t, base->end, | ^~~~~ cc1: all warnings being treated as errors which looks like a real problem: our phys_addr_t is only 32 bits now, so having 34-bit masks is just going to result in overflows. Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240731162159.9235-2-palmer@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Haibo Xu authored
Currently, only acpi_early_node_map[0] was initialized to NUMA_NO_NODE. To ensure all the values were properly initialized, switch to initialize all of them to NUMA_NO_NODE. Suggested-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Haibo Xu <haibo1.xu@intel.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> (arm64 platform) Reviewed-by: Sunil V L <sunilvl@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20240729035958.1957185-1-haibo1.xu@intel.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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- 19 Sep, 2024 3 commits
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Palmer Dabbelt authored
Samuel Holland <samuel.holland@sifive.com> says: This series fixes two areas where uninstrumented assembly routines caused gaps in KASAN coverage on RISC-V, which were caught by KUnit tests. The KASAN KUnit test suite passes after applying this series. This series fixes the following test failures: # kasan_strings: EXPECTATION FAILED at mm/kasan/kasan_test.c:1520 KASAN failure expected in "kasan_int_result = strcmp(ptr, "2")", but none occurred # kasan_strings: EXPECTATION FAILED at mm/kasan/kasan_test.c:1524 KASAN failure expected in "kasan_int_result = strlen(ptr)", but none occurred not ok 60 kasan_strings # kasan_bitops_generic: EXPECTATION FAILED at mm/kasan/kasan_test.c:1531 KASAN failure expected in "set_bit(nr, addr)", but none occurred # kasan_bitops_generic: EXPECTATION FAILED at mm/kasan/kasan_test.c:1533 KASAN failure expected in "clear_bit(nr, addr)", but none occurred # kasan_bitops_generic: EXPECTATION FAILED at mm/kasan/kasan_test.c:1535 KASAN failure expected in "clear_bit_unlock(nr, addr)", but none occurred # kasan_bitops_generic: EXPECTATION FAILED at mm/kasan/kasan_test.c:1536 KASAN failure expected in "__clear_bit_unlock(nr, addr)", but none occurred # kasan_bitops_generic: EXPECTATION FAILED at mm/kasan/kasan_test.c:1537 KASAN failure expected in "change_bit(nr, addr)", but none occurred # kasan_bitops_generic: EXPECTATION FAILED at mm/kasan/kasan_test.c:1543 KASAN failure expected in "test_and_set_bit(nr, addr)", but none occurred # kasan_bitops_generic: EXPECTATION FAILED at mm/kasan/kasan_test.c:1545 KASAN failure expected in "test_and_set_bit_lock(nr, addr)", but none occurred # kasan_bitops_generic: EXPECTATION FAILED at mm/kasan/kasan_test.c:1546 KASAN failure expected in "test_and_clear_bit(nr, addr)", but none occurred # kasan_bitops_generic: EXPECTATION FAILED at mm/kasan/kasan_test.c:1548 KASAN failure expected in "test_and_change_bit(nr, addr)", but none occurred not ok 61 kasan_bitops_generic Samuel Holland (2): riscv: Omit optimized string routines when using KASAN riscv: Enable bitops instrumentation arch/riscv/include/asm/bitops.h | 43 ++++++++++++++++++--------------- arch/riscv/include/asm/string.h | 2 ++ arch/riscv/kernel/riscv_ksyms.c | 3 --- arch/riscv/lib/Makefile | 2 ++ arch/riscv/lib/strcmp.S | 1 + arch/riscv/lib/strlen.S | 1 + arch/riscv/lib/strncmp.S | 1 + arch/riscv/purgatory/Makefile | 2 ++ 8 files changed, 32 insertions(+), 23 deletions(-) * b4-shazam-merge: riscv: Enable bitops instrumentation riscv: Omit optimized string routines when using KASAN Link: https://lore.kernel.org/r/20240801033725.28816-1-samuel.holland@sifive.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Samuel Holland authored
Instead of implementing the bitops functions directly in assembly, provide the arch_-prefixed versions and use the wrappers from asm-generic to add instrumentation. This improves KASAN coverage and fixes the kasan_bitops_generic() unit test. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240801033725.28816-3-samuel.holland@sifive.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Samuel Holland authored
The optimized string routines are implemented in assembly, so they are not instrumented for use with KASAN. Fall back to the C version of the routines in order to improve KASAN coverage. This fixes the kasan_strings() unit test. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240801033725.28816-2-samuel.holland@sifive.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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- 17 Sep, 2024 7 commits
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Hanjun Guo authored
acpi_numa_get_nid() is only called in acpi_numa.c for riscv, no need to add it in head file, so make it static and remove related functions in the asm/acpi.h. Spotted by doing some cleanup for arm64 ACPI. Signed-off-by: Hanjun Guo <guohanjun@huawei.com> Reviewed-by: Haibo Xu <haibo1.xu@intel.com> Link: https://lore.kernel.org/r/20240811031804.3347298-1-guohanjun@huawei.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Yunhui Cui authored
Implement arch_align_stack() to randomize the lower bits of the stack address. Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> Link: https://lore.kernel.org/r/20240625030502.68988-1-cuiyunhui@bytedance.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Charlie Jenkins authored
Macros needed for 32-bit compilations were hidden behind 64-bit riscv ifdefs. Fix the 32-bit compilations by moving macros to allow the memory_layout test to run on 32-bit. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Fixes: 73d05262 ("selftests: riscv: Generalize mm selftests") Link: https://lore.kernel.org/r/20240808-mmap_tests__fixes-v1-1-b1344b642a84@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Charlie Jenkins authored
Since this array is only used in this file, it should be static. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202407241530.ej5SVgX1-lkp@intel.com/Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240807-make_andes_static-v1-1-b64bf4c3d941@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jinjie Ruan authored
list_head can be initialized automatically with LIST_HEAD() instead of calling INIT_LIST_HEAD(). Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Tested-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240904013344.2026738-1-ruanjinjie@huawei.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Geert Uytterhoeven authored
There is not much point in keeping support for RZ/Five peripherals enabled, as the RZ/Five platform option (ARCH_R9A07G043) is gated behind NONPORTABLE. Hence drop all config options that enable built-in or modular support for peripherals found on RZ/Five SoCs. Disable USB_XHCI_RCAR explicitly, as its value defaults to the value of ARCH_RENESAS, which is still enabled. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com> Link: https://lore.kernel.org/r/89ad70c7d6e8078208fecfd41dc03f6028531729.1722353710.git.geert+renesas@glider.beSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jinjie Ruan authored
Until now, the generic weak kgdb_roundup_cpus() has been used for kgdb on RISCV. A custom one allows to debug CPUs that are stuck with interrupts disabled with NMI support in the future. And using an IPI is better than the generic one since it avoids the potential situation described in the generic kgdb_call_nmi_hook(). As Andrew pointed out, once there is NMI support, we can easily extend this and the CPU backtrace support to use NMIs. After this patch, the kgdb test show that: # echo g > /proc/sysrq-trigger [2]kdb> btc btc: cpu status: Currently on cpu 2 Available cpus: 0-1(-), 2, 3(-) Stack traceback for pid 0 0xffffffff81c13a40 0 0 1 0 - 0xffffffff81c14510 swapper/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.10.0-g3120273055b6-dirty #51 Hardware name: riscv-virtio,qemu (DT) Call Trace: [<ffffffff80006c48>] dump_backtrace+0x28/0x30 [<ffffffff80fceb38>] show_stack+0x38/0x44 [<ffffffff80fe6a04>] dump_stack_lvl+0x58/0x7a [<ffffffff80fe6a3e>] dump_stack+0x18/0x20 [<ffffffff801143fa>] kgdb_cpu_enter+0x682/0x6b2 [<ffffffff801144ca>] kgdb_nmicallback+0xa0/0xac [<ffffffff8000a392>] handle_IPI+0x9c/0x120 [<ffffffff800a2baa>] handle_percpu_devid_irq+0xa4/0x1e4 [<ffffffff8009cca8>] generic_handle_domain_irq+0x28/0x36 [<ffffffff800a9e5c>] ipi_mux_process+0xe8/0x110 [<ffffffff806e1e30>] imsic_handle_irq+0xf8/0x13a [<ffffffff8009cca8>] generic_handle_domain_irq+0x28/0x36 [<ffffffff806dff12>] riscv_intc_aia_irq+0x2e/0x40 [<ffffffff80fe6ab0>] handle_riscv_irq+0x54/0x86 [<ffffffff80ff2e4a>] call_on_irq_stack+0x32/0x40 Rebased on Ryo Takakura's "RISC-V: Enable IPI CPU Backtrace" patch. Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20240727063438.886155-1-ruanjinjie@huawei.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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- 16 Sep, 2024 8 commits
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Jisheng Zhang authored
Inspired by[1], modify the code to remove the code of modifying ra to avoid imbalance RAS (return address stack) which may lead to incorret predictions on return. Link: https://lore.kernel.org/linux-riscv/20240607061335.2197383-1-cyrilbur@tenstorrent.com/ [1] Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Cyril Bur <cyrilbur@tenstorrent.com> Link: https://lore.kernel.org/r/20240720170659.1522-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
Alexandre Ghiti <alexghiti@rivosinc.com> says: In RISC-V, after a new mapping is established, a sfence.vma needs to be emitted for different reasons: - if the uarch caches invalid entries, we need to invalidate it otherwise we would trap on this invalid entry, - if the uarch does not cache invalid entries, a reordered access could fail to see the new mapping and then trap (sfence.vma acts as a fence). We can actually avoid emitting those (mostly) useless and costly sfence.vma by handling the traps instead: - for new kernel mappings: only vmalloc mappings need to be taken care of, other new mapping are rare and already emit the required sfence.vma if needed. That must be achieved very early in the exception path as explained in patch 3, and this also fixes our fragile way of dealing with vmalloc faults. - for new user mappings: Svvptc makes update_mmu_cache() a no-op but we can take some gratuitous page faults (which are very unlikely though). Patch 1 and 2 introduce Svvptc extension probing. On our uarch that does not cache invalid entries and a 6.5 kernel, the gains are measurable: * Kernel boot: 6% * ltp - mmapstress01: 8% * lmbench - lat_pagefault: 20% * lmbench - lat_mmap: 5% Here are the corresponding numbers of sfence.vma emitted: * Ubuntu boot to login: Before: ~630k sfence.vma After: ~200k sfence.vma * ltp - mmapstress01 Before: ~45k After: ~6.3k * lmbench - lat_pagefault Before: ~665k After: 832 (!) * lmbench - lat_mmap Before: ~546k After: 718 (!) Thanks to Ved and Matt Evans for triggering the discussion that led to this patchset! * b4-shazam-merge: riscv: Stop emitting preventive sfence.vma for new userspace mappings with Svvptc riscv: Stop emitting preventive sfence.vma for new vmalloc mappings dt-bindings: riscv: Add Svvptc ISA extension description riscv: Add ISA extension parsing for Svvptc Link: https://lore.kernel.org/r/20240717060125.139416-1-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Steffen Persvold authored
commit 5944ce09 (arch_topology: Build cacheinfo from primary CPU) removed the init_cache_level() function from arch/riscv/kernel/cacheinfo.c and relies on the init_cpu_topology() function in drivers/base/arch_topology.c to call fetch_cache_info() which in turn calls init_of_cache_level() to populate the cache hierarchy information. However, init_cpu_topology() is only called from smpboot.c:smp_prepare_cpus() and thus only available when CONFIG_SMP is defined. To support non-SMP enabled kernels to still detect cache hierarchy, we add back the init_cache_level() function. The init_level_allocate_ci() function handles this gracefully on SMP-enabled kernels anyway where fetch_cache_info() is called from init_cpu_topology() earlier in the boot phase. Signed-off-by: Steffen Persvold <spersvold@gmail.com> Link: https://lore.kernel.org/r/20240707003515.5058-1-spersvold@gmail.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jinjie Ruan authored
Since commit f0bddf50 ("riscv: entry: Convert to generic entry"), _TIF_WORK_MASK is no longer used, so remove it. Fixes: f0bddf50 ("riscv: entry: Convert to generic entry") Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Andy Chiu <andy.chiu@sifive.com> Link: https://lore.kernel.org/r/20240711111508.1373322-1-ruanjinjie@huawei.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
Jisheng Zhang <jszhang@kernel.org> says: commit 76329c69 ("riscv: Use SYM_*() assembly macros instead of deprecated ones"), most riscv has been to converted the new style SYM_ assembler annotations. The remaining one is sifive's errata_cip_453.S, so convert to new style SYM_ annotations as well. After that select ARCH_USE_SYM_ANNOTATIONS. * b4-shazam-merge: riscv: select ARCH_USE_SYM_ANNOTATIONS riscv: errata: sifive: Use SYM_*() assembly macros Link: https://lore.kernel.org/r/20240709160536.3690-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Xiao Wang authored
The macro CONFIG_RISCV_PMU must have been defined when riscv_pmu.c gets compiled, so this patch removes the redundant check. Signed-off-by: Xiao Wang <xiao.w.wang@intel.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20240708121224.1148154-1-xiao.w.wang@intel.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Palmer Dabbelt authored
Jinjie Ruan <ruanjinjie@huawei.com> says: Add RISC-V USER_STACKTRACE support, and fix the fp alignment bug in perf_callchain_user() by the way as Björn pointed out. * b4-shazam-merge: riscv: stacktrace: Add USER_STACKTRACE support riscv: Fix fp alignment bug in perf_callchain_user() Link: https://lore.kernel.org/r/20240708032847.2998158-1-ruanjinjie@huawei.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jisheng Zhang authored
This is used in poison.h for poison pointer offset. Based on current SV39, SV48 and SV57 vm layout, 0xdead000000000000 is a proper value that is not mappable, this can avoid potentially turning an oops to an expolit. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Fixes: fbe934d6 ("RISC-V: Build Infrastructure") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240705170210.3236-1-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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- 15 Sep, 2024 8 commits
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Alexandre Ghiti authored
The preventive sfence.vma were emitted because new mappings must be made visible to the page table walker but Svvptc guarantees that it will happen within a bounded timeframe, so no need to sfence.vma for the uarchs that implement this extension, we will then take gratuitous (but very unlikely) page faults, similarly to x86 and arm64. This allows to drastically reduce the number of sfence.vma emitted: * Ubuntu boot to login: Before: ~630k sfence.vma After: ~200k sfence.vma * ltp - mmapstress01 Before: ~45k After: ~6.3k * lmbench - lat_pagefault Before: ~665k After: 832 (!) * lmbench - lat_mmap Before: ~546k After: 718 (!) Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240717060125.139416-5-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Alexandre Ghiti authored
In 6.5, we removed the vmalloc fault path because that can't work (see [1] [2]). Then in order to make sure that new page table entries were seen by the page table walker, we had to preventively emit a sfence.vma on all harts [3] but this solution is very costly since it relies on IPI. And even there, we could end up in a loop of vmalloc faults if a vmalloc allocation is done in the IPI path (for example if it is traced, see [4]), which could result in a kernel stack overflow. Those preventive sfence.vma needed to be emitted because: - if the uarch caches invalid entries, the new mapping may not be observed by the page table walker and an invalidation may be needed. - if the uarch does not cache invalid entries, a reordered access could "miss" the new mapping and traps: in that case, we would actually only need to retry the access, no sfence.vma is required. So this patch removes those preventive sfence.vma and actually handles the possible (and unlikely) exceptions. And since the kernel stacks mappings lie in the vmalloc area, this handling must be done very early when the trap is taken, at the very beginning of handle_exception: this also rules out the vmalloc allocations in the fault path. Link: https://lore.kernel.org/linux-riscv/20230531093817.665799-1-bjorn@kernel.org/ [1] Link: https://lore.kernel.org/linux-riscv/20230801090927.2018653-1-dylan@andestech.com [2] Link: https://lore.kernel.org/linux-riscv/20230725132246.817726-1-alexghiti@rivosinc.com/ [3] Link: https://lore.kernel.org/lkml/20200508144043.13893-1-joro@8bytes.org/ [4] Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Yunhui Cui <cuiyunhui@bytedance.com> Link: https://lore.kernel.org/r/20240717060125.139416-4-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Alexandre Ghiti authored
Add description for the Svvptc ISA extension which was ratified recently. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240717060125.139416-3-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Alexandre Ghiti authored
Add support to parse the Svvptc string in the riscv,isa string. Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240717060125.139416-2-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jisheng Zhang authored
Now, riscv has been converted to the new style SYM_ assembler annotations. So select ARCH_USE_SYM_ANNOTATIONS to ensure the deprecated macros such as ENTRY(), END(), WEAK() and so on are not available and we don't regress. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-By: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20240709160536.3690-3-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jisheng Zhang authored
ENTRY()/END() macros are deprecated and we should make use of the new SYM_*() macros [1] for better annotation of symbols. Replace the deprecated ones with the new ones. [1] https://docs.kernel.org/core-api/asm-annotations.htmlSigned-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-By: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20240709160536.3690-2-jszhang@kernel.orgSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jinjie Ruan authored
Currently, userstacktrace is unsupported for riscv. So use the perf_callchain_user() code as blueprint to implement the arch_stack_walk_user() which add userstacktrace support on riscv. Meanwhile, we can use arch_stack_walk_user() to simplify the implementation of perf_callchain_user(). A ftrace test case is shown as below: # cd /sys/kernel/debug/tracing # echo 1 > options/userstacktrace # echo 1 > options/sym-userobj # echo 1 > events/sched/sched_process_fork/enable # cat trace ...... bash-178 [000] ...1. 97.968395: sched_process_fork: comm=bash pid=178 child_comm=bash child_pid=231 bash-178 [000] ...1. 97.970075: <user stack trace> => /lib/libc.so.6[+0xb5090] Also a simple perf test is ok as below: # perf record -e cpu-clock --call-graph fp top # perf report --call-graph ..... [[31m 66.54%[[m 0.00% top [kernel.kallsyms] [k] ret_from_exception | ---ret_from_exception | |--[[31m58.97%[[m--do_trap_ecall_u | | | |--[[31m17.34%[[m--__riscv_sys_read | | ksys_read | | | | | --[[31m16.88%[[m--vfs_read | | | | | |--[[31m10.90%[[m--seq_read Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Tested-by: Jinjie Ruan <ruanjinjie@huawei.com> Cc: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/r/20240708032847.2998158-3-ruanjinjie@huawei.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Jinjie Ruan authored
The standard RISC-V calling convention said: "The stack grows downward and the stack pointer is always kept 16-byte aligned". So perf_callchain_user() should check whether 16-byte aligned for fp. Link: https://riscv.org/wp-content/uploads/2015/01/riscv-calling.pdf Fixes: dbeb90b0 ("riscv: Add perf callchain support") Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> Cc: Björn Töpel <bjorn@kernel.org> Link: https://lore.kernel.org/r/20240708032847.2998158-2-ruanjinjie@huawei.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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- 14 Sep, 2024 2 commits
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Stuart Menefy authored
The original reason for reserving the top 4GiB of the direct map (space for modules/BPF/kernel) hasn't applied since the address map was reworked for KASAN. Signed-off-by: Stuart Menefy <stuart.menefy@codasip.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240624121723.2186279-1-stuart.menefy@codasip.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Changbin Du authored
The vdso.so.dbg is a debug version of vdso and could be used for debugging purpose. For example, perf-annotate requires debugging info to show source lines. So let's keep its debugging info. Signed-off-by: Changbin Du <changbin.du@huawei.com> Reviewed-by: Cyril Bur <cyrilbur@tenstorrent.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240611040947.3024710-1-changbin.du@huawei.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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- 12 Sep, 2024 5 commits
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Palmer Dabbelt authored
Nam Cao <namcao@linutronix.de> says: Hi, For XIP kernel, the writable data section is always at offset specified in XIP_OFFSET, which is hard-coded to 32MB. Unfortunately, this means the read-only section (placed before the writable section) is restricted in size. This causes build failure if the kernel gets too large. This series remove the use of XIP_OFFSET one by one, then remove this macro entirely at the end, with the goal of lifting this size restriction. Also some cleanup and documentation along the way. * b4-shazam-merge riscv: remove limit on the size of read-only section for XIP kernel riscv: drop the use of XIP_OFFSET in create_kernel_page_table() riscv: drop the use of XIP_OFFSET in kernel_mapping_va_to_pa() riscv: drop the use of XIP_OFFSET in XIP_FIXUP_FLASH_OFFSET riscv: drop the use of XIP_OFFSET in XIP_FIXUP_OFFSET riscv: replace misleading va_kernel_pa_offset on XIP kernel riscv: don't export va_kernel_pa_offset in vmcoreinfo for XIP kernel riscv: cleanup XIP_FIXUP macro riscv: change XIP's kernel_map.size to be size of the entire kernel ... Link: https://lore.kernel.org/r/cover.1717789719.git.namcao@linutronix.deSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Nam Cao authored
XIP_OFFSET is the hard-coded offset of writable data section within the kernel. By hard-coding this value, the read-only section of the kernel (which is placed before the writable data section) is restricted in size. This causes build failures if the kernel gets too big [1]. Remove this limit. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202404211031.J6l2AfJk-lkp@intel.com [1] Signed-off-by: Nam Cao <namcao@linutronix.de> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/3bf3a77be10ebb0d8086c028500baa16e7a8e648.1717789719.git.namcao@linutronix.deSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Nam Cao authored
XIP_OFFSET is the hard-coded offset of writable data section within the kernel. By hard-coding this value, the read-only section of the kernel (which is placed before the writable data section) is restricted in size. As a preparation to remove this hard-coded value entirely, stop using XIP_OFFSET in create_kernel_page_table(). Instead use _sdata and _start to do the same thing. Signed-off-by: Nam Cao <namcao@linutronix.de> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/4ea3f222a7eb9f91c04b155ff2e4d3ef19158acc.1717789719.git.namcao@linutronix.deSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Nam Cao authored
XIP_OFFSET is the hard-coded offset of writable data section within the kernel. By hard-coding this value, the read-only section of the kernel (which is placed before the writable data section) is restricted in size. As a preparation to remove this hard-coded macro XIP_OFFSET entirely, remove the use of XIP_OFFSET in kernel_mapping_va_to_pa(). The macro XIP_OFFSET is used in this case to check if the virtual address is mapped to Flash or to RAM. The same check can be done with kernel_map.xiprom_sz. Signed-off-by: Nam Cao <namcao@linutronix.de> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/644c13d9467525a06f5d63d157875a35b2edb4bc.1717789719.git.namcao@linutronix.deSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Nam Cao authored
XIP_OFFSET is the hard-coded offset of writable data section within the kernel. By hard-coding this value, the read-only section of the kernel (which is placed before the writable data section) is restricted in size. As a preparation to remove this hard-coded macro XIP_OFFSET entirely, stop using XIP_OFFSET in XIP_FIXUP_FLASH_OFFSET. Instead, use __data_loc and _sdata to do the same thing. While at it, also add a description for XIP_FIXUP_FLASH_OFFSET. Signed-off-by: Nam Cao <namcao@linutronix.de> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/7b3319657edd1822f3457e7e7c07aaa326cc2f87.1717789719.git.namcao@linutronix.deSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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