summaryrefslogtreecommitdiff
path: root/arch/riscv/kernel
AgeCommit message (Collapse)Author
2024-09-24Merge tag 'riscv-for-linus-6.12-mw1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support using Zkr to seed KASLR - Support IPI-triggered CPU backtracing - Support for generic CPU vulnerabilities reporting to userspace - A few cleanups for missing licenses - The size limit on the XIP kernel has been removed - Support for tracing userspace stacks - Support for the Svvptc extension - Various cleanups and fixes throughout the tree * tag 'riscv-for-linus-6.12-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (47 commits) crash: Fix riscv64 crash memory reserve dead loop perf/riscv-sbi: Add platform specific firmware event handling tools: Optimize ring buffer for riscv tools: Add riscv barrier implementation RISC-V: Don't have MAX_PHYSMEM_BITS exceed phys_addr_t ACPI: NUMA: initialize all values of acpi_early_node_map to NUMA_NO_NODE riscv: Enable bitops instrumentation riscv: Omit optimized string routines when using KASAN ACPI: RISCV: Make acpi_numa_get_nid() to be static riscv: Randomize lower bits of stack address selftests: riscv: Allow mmap test to compile on 32-bit riscv: Make riscv_isa_vendor_ext_andes array static riscv: Use LIST_HEAD() to simplify code riscv: defconfig: Disable RZ/Five peripheral support RISC-V: Implement kgdb_roundup_cpus() to enable future NMI Roundup riscv: avoid Imbalance in RAS riscv: cacheinfo: Add back init_cache_level() function riscv: Remove unused _TIF_WORK_MASK drivers/perf: riscv: Remove redundant macro check riscv: define ILLEGAL_POINTER_VALUE for 64bit ...
2024-09-20ACPI: NUMA: initialize all values of acpi_early_node_map to NUMA_NO_NODEHaibo Xu
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-19Merge patch series "riscv: Improve KASAN coverage to fix unit tests"Palmer Dabbelt
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-19riscv: Omit optimized string routines when using KASANSamuel Holland
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-17ACPI: RISCV: Make acpi_numa_get_nid() to be staticHanjun Guo
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-17riscv: Randomize lower bits of stack addressYunhui Cui
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-17riscv: Make riscv_isa_vendor_ext_andes array staticCharlie Jenkins
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-17riscv: Use LIST_HEAD() to simplify codeJinjie Ruan
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-17RISC-V: Implement kgdb_roundup_cpus() to enable future NMI RoundupJinjie Ruan
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-15riscv: avoid Imbalance in RASJisheng Zhang
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.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-15Merge patch series "Svvptc extension to remove preventive sfence.vma"Palmer Dabbelt
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-15riscv: cacheinfo: Add back init_cache_level() functionSteffen Persvold
commit 5944ce092b97 (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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-15Merge patch series "riscv: stacktrace: Add USER_STACKTRACE support"Palmer Dabbelt
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-15riscv: Stop emitting preventive sfence.vma for new vmalloc mappingsAlexandre Ghiti
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-15riscv: Add ISA extension parsing for SvvptcAlexandre Ghiti
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-14riscv: stacktrace: Add USER_STACKTRACE supportJinjie Ruan
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-14riscv: Fix fp alignment bug in perf_callchain_user()Jinjie Ruan
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: dbeb90b0c1eb ("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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-14riscv: vdso: do not strip debugging info for vdso.so.dbgChangbin Du
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.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-12Merge patch series "remove size limit on XIP kernel"Palmer Dabbelt
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.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-12riscv: remove limit on the size of read-only section for XIP kernelNam Cao
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.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-12riscv: don't export va_kernel_pa_offset in vmcoreinfo for XIP kernelNam Cao
The crash utility uses va_kernel_pa_offset to translate virtual addresses. This is incorrect in the case of XIP kernel, because va_kernel_pa_offset is not the virtual-physical address offset (yes, the name is misleading; this variable will be removed for XIP in a following commit). Stop exporting this variable for XIP kernel. The replacement is to be determined, note it as a TODO for now. Signed-off-by: Nam Cao <namcao@linutronix.de> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/8f8760d3f9a11af4ea0acbc247e4f49ff5d317e9.1717789719.git.namcao@linutronix.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-09-11Merge branch 'acpi-riscv'Rafael J. Wysocki
Merge ACPI and irqchip updates related to external interrupt controller support on RISC-V: - Add ACPI device enumeration support for interrupt controller probing including taking dependencies into account (Sunil V L). - Implement ACPI-based interrupt controller probing on RISC-V (Sunil V L). - Add ACPI support for AIA in riscv-intc and add ACPI support to riscv-imsic, riscv-aplic, and sifive-plic (Sunil V L). * acpi-riscv: irqchip/sifive-plic: Add ACPI support irqchip/riscv-aplic: Add ACPI support irqchip/riscv-imsic: Add ACPI support irqchip/riscv-imsic-state: Create separate function for DT irqchip/riscv-intc: Add ACPI support for AIA ACPI: RISC-V: Implement function to add implicit dependencies ACPI: RISC-V: Initialize GSI mapping structures ACPI: RISC-V: Implement function to reorder irqchip probe entries ACPI: RISC-V: Implement PCI related functionality ACPI: pci_link: Clear the dependencies after probe ACPI: bus: Add RINTC IRQ model for RISC-V ACPI: scan: Define weak function to populate dependencies ACPI: scan: Add RISC-V interrupt controllers to honor list ACPI: scan: Refactor dependency creation ACPI: bus: Add acpi_riscv_init() function ACPI: scan: Add a weak arch_sort_irqchip_probe() to order the IRQCHIP probe arm64: PCI: Migrate ACPI related functions to pci-acpi.c
2024-09-03riscv: Fix RISCV_ALTERNATIVE_EARLYAlexandre Ghiti
RISCV_ALTERNATIVE_EARLY will issue sbi_ecall() very early in the boot process, before the first memory mapping is setup so we can't have any instrumentation happening here. In addition, when the kernel is relocatable, we must also not issue any relocation this early since they would have been patched virtually only. So, instead of disabling instrumentation for the whole kernel/sbi.c file and compiling it with -fno-pie, simply move __sbi_ecall() and __sbi_base_ecall() into their own file where this is fixed. Reported-by: Conor Dooley <conor.dooley@microchip.com> Closes: https://lore.kernel.org/linux-riscv/20240813-pony-truck-3e7a83e9759e@spud/ Reported-by: syzbot+cfbcb82adf6d7279fd35@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-riscv/00000000000065062c061fcec37b@google.com/ Fixes: 1745cfafebdf ("riscv: don't use global static vars to store alternative data") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240829165048.49756-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-31riscv: misaligned: Restrict user access to kernel memorySamuel Holland
raw_copy_{to,from}_user() do not call access_ok(), so this code allowed userspace to access any virtual memory address. Cc: stable@vger.kernel.org Fixes: 7c83232161f6 ("riscv: add support for misaligned trap handling in S-mode") Fixes: 441381506ba7 ("riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code") Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240815005714.1163136-1-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-27ACPI: RISC-V: Implement PCI related functionalitySunil V L
Replace the dummy implementation for PCI related functions with actual implementation. This needs ECAM and MCFG CONFIG options to be enabled for RISC-V. Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Tested-by: Björn Töpel <bjorn@rivosinc.com> Link: https://patch.msgid.link/20240812005929.113499-10-sunilvl@ventanamicro.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2024-08-15Merge patch series "RISC-V: hwprobe: Misaligned scalar perf fix and rename"Palmer Dabbelt
Evan Green <evan@rivosinc.com> says: The CPUPERF0 hwprobe key was documented and identified in code as a bitmask value, but its contents were an enum. This produced incorrect behavior in conjunction with the WHICH_CPUS hwprobe flag. The first patch in this series fixes the bitmask/enum problem by creating a new hwprobe key that returns the same data, but is properly described as a value instead of a bitmask. The second patch renames the value definitions in preparation for adding vector misaligned access info. As of this version, the old defines are kept in place to maintain source compatibility with older userspace programs. * b4-shazam-merge: RISC-V: hwprobe: Add SCALAR to misaligned perf defines RISC-V: hwprobe: Add MISALIGNED_PERF key Link: https://lore.kernel.org/r/20240809214444.3257596-1-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-15riscv: Fix out-of-bounds when accessing Andes per hart vendor extension arrayAlexandre Ghiti
The out-of-bounds access is reported by UBSAN: [ 0.000000] UBSAN: array-index-out-of-bounds in ../arch/riscv/kernel/vendor_extensions.c:41:66 [ 0.000000] index -1 is out of range for type 'riscv_isavendorinfo [32]' [ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.11.0-rc2ubuntu-defconfig #2 [ 0.000000] Hardware name: riscv-virtio,qemu (DT) [ 0.000000] Call Trace: [ 0.000000] [<ffffffff94e078ba>] dump_backtrace+0x32/0x40 [ 0.000000] [<ffffffff95c83c1a>] show_stack+0x38/0x44 [ 0.000000] [<ffffffff95c94614>] dump_stack_lvl+0x70/0x9c [ 0.000000] [<ffffffff95c94658>] dump_stack+0x18/0x20 [ 0.000000] [<ffffffff95c8bbb2>] ubsan_epilogue+0x10/0x46 [ 0.000000] [<ffffffff95485a82>] __ubsan_handle_out_of_bounds+0x94/0x9c [ 0.000000] [<ffffffff94e09442>] __riscv_isa_vendor_extension_available+0x90/0x92 [ 0.000000] [<ffffffff94e043b6>] riscv_cpufeature_patch_func+0xc4/0x148 [ 0.000000] [<ffffffff94e035f8>] _apply_alternatives+0x42/0x50 [ 0.000000] [<ffffffff95e04196>] apply_boot_alternatives+0x3c/0x100 [ 0.000000] [<ffffffff95e05b52>] setup_arch+0x85a/0x8bc [ 0.000000] [<ffffffff95e00ca0>] start_kernel+0xa4/0xfb6 The dereferencing using cpu should actually not happen, so remove it. Fixes: 23c996fc2bc1 ("riscv: Extend cpufeature.c to detect vendor extensions") Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240814192619.276794-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-14riscv/kexec_file: Fix relocation type R_RISCV_ADD16 and R_RISCV_SUB16 unknownYing Sun
Runs on the kernel with CONFIG_RISCV_ALTERNATIVE enabled: kexec -sl vmlinux Error: kexec_image: Unknown rela relocation: 34 kexec_image: Error loading purgatory ret=-8 and kexec_image: Unknown rela relocation: 38 kexec_image: Error loading purgatory ret=-8 The purgatory code uses the 16-bit addition and subtraction relocation type, but not handled, resulting in kexec_file_load failure. So add handle to arch_kexec_apply_relocations_add(). Tested on RISC-V64 Qemu-virt, issue fixed. Co-developed-by: Petr Tesarik <petr@tesarici.cz> Signed-off-by: Petr Tesarik <petr@tesarici.cz> Signed-off-by: Ying Sun <sunying@isrc.iscas.ac.cn> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20240711083236.2859632-1-sunying@isrc.iscas.ac.cn Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-14RISC-V: hwprobe: Add SCALAR to misaligned perf definesEvan Green
In preparation for misaligned vector performance hwprobe keys, rename the hwprobe key values associated with misaligned scalar accesses to include the term SCALAR. Leave the old defines in place to maintain source compatibility. This change is intended to be a functional no-op. Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240809214444.3257596-3-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-14RISC-V: hwprobe: Add MISALIGNED_PERF keyEvan Green
RISCV_HWPROBE_KEY_CPUPERF_0 was mistakenly flagged as a bitmask in hwprobe_key_is_bitmask(), when in reality it was an enum value. This causes problems when used in conjunction with RISCV_HWPROBE_WHICH_CPUS, since SLOW, FAST, and EMULATED have values whose bits overlap with each other. If the caller asked for the set of CPUs that was SLOW or EMULATED, the returned set would also include CPUs that were FAST. Introduce a new hwprobe key, RISCV_HWPROBE_KEY_MISALIGNED_PERF, which returns the same values in response to a direct query (with no flags), but is properly handled as an enumerated value. As a result, SLOW, FAST, and EMULATED are all correctly treated as distinct values under the new key when queried with the WHICH_CPUS flag. Leave the old key in place to avoid disturbing applications which may have already come to rely on the key, with or without its broken behavior with respect to the WHICH_CPUS flag. Fixes: e178bf146e4b ("RISC-V: hwprobe: Introduce which-cpus flag") Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20240809214444.3257596-2-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-14RISC-V: ACPI: NUMA: initialize all values of acpi_early_node_map to NUMA_NO_NODEHaibo Xu
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. Fixes: eabd9db64ea8 ("ACPI: RISCV: Add NUMA support based on SRAT and SLIT") Reported-by: Andrew Jones <ajones@ventanamicro.com> Suggested-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Haibo Xu <haibo1.xu@intel.com> Reviewed-by: Sunil V L <sunilvl@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Hanjun Guo <guohanjun@huawei.com> Link: https://lore.kernel.org/r/0d362a8ae50558b95685da4c821b2ae9e8cf78be.1722828421.git.haibo1.xu@intel.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-14riscv: entry: always initialize regs->a0 to -ENOSYSCeleste Liu
Otherwise when the tracer changes syscall number to -1, the kernel fails to initialize a0 with -ENOSYS and subsequently fails to return the error code of the failed syscall to userspace. For example, it will break strace syscall tampering. Fixes: 52449c17bdd1 ("riscv: entry: set a0 = -ENOSYS only when syscall != -1") Reported-by: "Dmitry V. Levin" <ldv@strace.io> Reviewed-by: Björn Töpel <bjorn@rivosinc.com> Cc: stable@vger.kernel.org Signed-off-by: Celeste Liu <CoelacanthusHex@gmail.com> Link: https://lore.kernel.org/r/20240627142338.5114-2-CoelacanthusHex@gmail.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-07RISC-V: Enable IPI CPU BacktraceRyo Takakura
Add arch_trigger_cpumask_backtrace() which is a generic infrastructure for sampling other CPUs' backtrace using IPI. The feature is used when lockups are detected or in case of oops/panic if parameters are set accordingly. Below is the case of oops with the oops_all_cpu_backtrace enabled. $ sysctl kernel.oops_all_cpu_backtrace=1 triggering oops shows: [ 212.214237] NMI backtrace for cpu 1 [ 212.214390] CPU: 1 PID: 610 Comm: in:imklog Tainted: G OE 6.10.0-rc6 #1 [ 212.214570] Hardware name: riscv-virtio,qemu (DT) [ 212.214690] epc : fallback_scalar_usercopy+0x8/0xdc [ 212.214809] ra : _copy_to_user+0x20/0x40 [ 212.214913] epc : ffffffff80c3a930 ra : ffffffff8059ba7e sp : ff20000000eabb50 [ 212.215061] gp : ffffffff82066f90 tp : ff6000008e958000 t0 : 3463303866660000 [ 212.215210] t1 : 000000000000005b t2 : 3463303866666666 s0 : ff20000000eabb60 [ 212.215358] s1 : 0000000000000386 a0 : 00007ff6e81df926 a1 : ff600000824df800 [ 212.215505] a2 : 000000000000003f a3 : 7fffffffffffffc0 a4 : 0000000000000000 [ 212.215651] a5 : 000000000000003f a6 : 0000000000000000 a7 : 0000000000000000 [ 212.215857] s2 : ff600000824df800 s3 : ffffffff82066cc0 s4 : 0000000000001c1a [ 212.216074] s5 : ffffffff8206a5a8 s6 : 00007ff6e81df926 s7 : ffffffff8206a5a0 [ 212.216278] s8 : ff600000824df800 s9 : ffffffff81e25de0 s10: 000000000000003f [ 212.216471] s11: ffffffff8206a59d t3 : ff600000824df812 t4 : ff600000824df812 [ 212.216651] t5 : ff600000824df818 t6 : 0000000000040000 [ 212.216796] status: 0000000000040120 badaddr: 0000000000000000 cause: 8000000000000001 [ 212.217035] [<ffffffff80c3a930>] fallback_scalar_usercopy+0x8/0xdc [ 212.217207] [<ffffffff80095f56>] syslog_print+0x1f4/0x2b2 [ 212.217362] [<ffffffff80096e5c>] do_syslog.part.0+0x94/0x2d8 [ 212.217502] [<ffffffff800979e8>] do_syslog+0x66/0x88 [ 212.217636] [<ffffffff803a5dda>] kmsg_read+0x44/0x5c [ 212.217764] [<ffffffff80392dbe>] proc_reg_read+0x7a/0xa8 [ 212.217952] [<ffffffff802ff726>] vfs_read+0xb0/0x24e [ 212.218090] [<ffffffff803001ba>] ksys_read+0x64/0xe4 [ 212.218264] [<ffffffff8030025a>] __riscv_sys_read+0x20/0x2c [ 212.218453] [<ffffffff80c4af9a>] do_trap_ecall_u+0x60/0x1d4 [ 212.218664] [<ffffffff80c56998>] ret_from_exception+0x0/0x64 Signed-off-by: Ryo Takakura <takakura@valinux.co.jp> Link: https://lore.kernel.org/r/20240718093659.158912-1-takakura@valinux.co.jp Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-06riscv: Re-introduce global icache flush in patch_text_XXX()Alexandre Ghiti
commit edf2d546bfd6 ("riscv: patch: Flush the icache right after patching to avoid illegal insns") mistakenly removed the global icache flush in patch_text_nosync() and patch_text_set_nosync() functions, so reintroduce them. Fixes: edf2d546bfd6 ("riscv: patch: Flush the icache right after patching to avoid illegal insns") Reported-by: Samuel Holland <samuel.holland@sifive.com> Closes: https://lore.kernel.org/linux-riscv/a28ddc26-d77a-470a-a33f-88144f717e86@sifive.com/ Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240801191404.55181-1-alexghiti@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-05Merge patch series "RISC-V: Parse DT for Zkr to seed KASLR"Palmer Dabbelt
Jesse Taube <jesse@rivosinc.com> says: Add functions to pi/fdt_early.c to help parse the FDT to check if the isa string has the Zkr extension. Then use the Zkr extension to seed the KASLR base address. The first two patches fix the visibility of symbols. * b4-shazam-merge: RISC-V: Use Zkr to seed KASLR base address RISC-V: pi: Add kernel/pi/pi.h RISC-V: lib: Add pi aliases for string functions RISC-V: pi: Force hidden visibility for all symbol references Link: https://lore.kernel.org/r/20240709173937.510084-1-jesse@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-05RISC-V: Use Zkr to seed KASLR base addressJesse Taube
Parse the device tree for Zkr in the isa string. If Zkr is present, use it to seed the kernel base address. On an ACPI system, as of this commit, there is no easy way to check if Zkr is present. Blindly running the instruction isn't an option as; we have to be able to trust the firmware. Signed-off-by: Jesse Taube <jesse@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Tested-by: Zong Li <zong.li@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240709173937.510084-5-jesse@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-05RISC-V: pi: Add kernel/pi/pi.hJesse Taube
Add pi.h header for declarations of the kernel/pi prefixed functions and any other related declarations. Suggested-by: Charlie Jenkins <charlie@rivosinc.com> Signed-off-by: Jesse Taube <jesse@rivosinc.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240709173937.510084-4-jesse@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-05RISC-V: pi: Force hidden visibility for all symbol referencesJesse Taube
Eliminate all GOT entries in the .pi section, by forcing hidden visibility for all symbol references, which informs the compiler that such references will be resolved at link time without the need for allocating GOT entries. Include linux/hidden.h in Makefile, like arm64, for the hidden visibility attribute. Signed-off-by: Jesse Taube <jesse@rivosinc.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240709173937.510084-2-jesse@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-08-02Merge tag 'riscv-for-linus-6.11-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: - A fix to avoid dropping some of the internal pseudo-extensions, which breaks *envcfg dependency parsing - The kernel entry address is now aligned in purgatory, which avoids a misaligned load that can lead to crash on systems that don't support misaligned accesses early in boot - The FW_SFENCE_VMA_RECEIVED perf event was duplicated in a handful of perf JSON configurations, one of them been updated to FW_SFENCE_VMA_ASID_SENT - The starfive cache driver is now restricted to 64-bit systems, as it isn't 32-bit clean - A fix for to avoid aliasing legacy-mode perf counters with software perf counters - VM_FAULT_SIGSEGV is now handled in the page fault code - A fix for stalls during CPU hotplug due to IPIs being disabled - A fix for memblock bounds checking. This manifests as a crash on systems with discontinuous memory maps that have regions that don't fit in the linear map * tag 'riscv-for-linus-6.11-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: Fix linear mapping checks for non-contiguous memory regions RISC-V: Enable the IPI before workqueue_online_cpu() riscv/mm: Add handling for VM_FAULT_SIGSEGV in mm_fault_error() perf: riscv: Fix selecting counters in legacy mode cache: StarFive: Require a 64-bit system perf arch events: Fix duplicate RISC-V SBI firmware event name riscv/purgatory: align riscv_kernel_entry riscv: cpufeature: Do not drop Linux-internal extensions
2024-08-02syscalls: fix syscall macros for newfstat/newfstatatArnd Bergmann
The __NR_newfstat and __NR_newfstatat macros accidentally got renamed in the conversion to the syscall.tbl format, dropping the 'new' portion of the name. In an unrelated change, the two syscalls are no longer architecture specific but are once more defined on all 64-bit architectures, so the 'newstat' ABI keyword can be dropped from the table as a simplification. Fixes: Fixes: 4fe53bf2ba0a ("syscalls: add generic scripts/syscall.tbl") Closes: https://lore.kernel.org/lkml/838053e0-b186-4e9f-9668-9a3384a71f23@app.fastmail.com/T/#t Reported-by: Florian Weimer <fweimer@redhat.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2024-08-01RISC-V: Enable the IPI before workqueue_online_cpu()Nick Hu
Sometimes the hotplug cpu stalls at the arch_cpu_idle() for a while after workqueue_online_cpu(). When cpu stalls at the idle loop, the reschedule IPI is pending. However the enable bit is not enabled yet so the cpu stalls at WFI until watchdog timeout. Therefore enable the IPI before the workqueue_online_cpu() to fix the issue. Fixes: 63c5484e7495 ("workqueue: Add multiple affinity scopes and interface to select them") Signed-off-by: Nick Hu <nick.hu@sifive.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20240717031714.1946036-1-nick.hu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-31riscv: cpufeature: Do not drop Linux-internal extensionsSamuel Holland
The Linux-internal Xlinuxenvcfg ISA extension is omitted from the riscv_isa_ext array because it has no DT binding and should not appear in /proc/cpuinfo. The logic added in commit 625034abd52a ("riscv: add ISA extensions validation callback") assumes all extensions are included in riscv_isa_ext, and so riscv_resolve_isa() wrongly drops Xlinuxenvcfg from the final ISA string. Instead, accept such Linux-internal ISA extensions as if they have no validation callback. Fixes: 625034abd52a ("riscv: add ISA extensions validation callback") Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20240718213011.2600150-1-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26RISC-V: Provide the frequency of time CSR via hwprobePalmer Dabbelt
The RISC-V architecture makes a real time counter CSR (via RDTIME instruction) available for applications in U-mode but there is no architected mechanism for an application to discover the frequency the counter is running at. Some applications (e.g., DPDK) use the time counter for basic performance analysis as well as fine grained time-keeping. Add support to the hwprobe system call to export the time CSR frequency to code running in U-mode. Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> Reviewed-by: Evan Green <evan@rivosinc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Acked-by: Punit Agrawal <punit.agrawal@bytedance.com> Link: https://lore.kernel.org/r/20240702033731.71955-2-cuiyunhui@bytedance.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26Merge patch series "RISC-V: Select ACPI PPTT drivers"Palmer Dabbelt
This series adds support for ACPI PPTT via cacheinfo. * b4-shazam-merge: RISC-V: Select ACPI PPTT drivers riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTT riscv: cacheinfo: remove the useless input parameter (node) of ci_leaf_init() Link: https://lore.kernel.org/r/20240617131425.7526-1-cuiyunhui@bytedance.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26Merge patch "Enable SPCR table for console output on RISC-V"Palmer Dabbelt
Sia Jee Heng <jeeheng.sia@starfivetech.com> says: The ACPI SPCR code has been used to enable console output for ARM64 and X86. The same code can be reused for RISC-V. Furthermore, SPCR table is mandated for headless system as outlined in the RISC-V BRS Specification, chapter 6. * b4-shazam-merge: RISC-V: ACPI: Enable SPCR table for console output on RISC-V Link: https://lore.kernel.org/r/20240502073751.102093-1-jeeheng.sia@starfivetech.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26riscv: enable HAVE_ARCH_STACKLEAKJisheng Zhang
Add support for the stackleak feature. Whenever the kernel returns to user space the kernel stack is filled with a poison value. At the same time, disables the plugin in EFI stub code because EFI stub is out of scope for the protection. Tested on qemu and milkv duo: / # echo STACKLEAK_ERASING > /sys/kernel/debug/provoke-crash/DIRECT [ 38.675575] lkdtm: Performing direct entry STACKLEAK_ERASING [ 38.678448] lkdtm: stackleak stack usage: [ 38.678448] high offset: 288 bytes [ 38.678448] current: 496 bytes [ 38.678448] lowest: 1328 bytes [ 38.678448] tracked: 1328 bytes [ 38.678448] untracked: 448 bytes [ 38.678448] poisoned: 14312 bytes [ 38.678448] low offset: 8 bytes [ 38.689887] lkdtm: OK: the rest of the thread stack is properly erased Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240623235316.2010-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26riscv: signal: Remove unlikely() from WARN_ON() conditionZhongqiu Han
"WARN_ON(unlikely(x))" is excessive. WARN_ON() already uses unlikely() internally. Signed-off-by: Zhongqiu Han <quic_zhonhan@quicinc.com> Reviewed-by: Bjorn Andersson <quic_bjorande@quicinc.com> Reviewed-by: Andy Chiu <andy.chiu@sifive.com> Link: https://lore.kernel.org/r/20240620033434.3778156-1-quic_zhonhan@quicinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-26riscv: Improve exception and system call latencyAnton Blanchard
Many CPUs implement return address branch prediction as a stack. The RISCV architecture refers to this as a return address stack (RAS). If this gets corrupted then the CPU will mispredict at least one but potentally many function returns. There are two issues with the current RISCV exception code: - We are using the alternate link stack (x5/t0) for the indirect branch which makes the hardware think this is a function return. This will corrupt the RAS. - We modify the return address of handle_exception to point to ret_from_exception. This will also corrupt the RAS. Testing the null system call latency before and after the patch: Visionfive2 (StarFive JH7110 / U74) baseline: 189.87 ns patched: 176.76 ns Lichee pi 4a (T-Head TH1520 / C910) baseline: 666.58 ns patched: 636.90 ns Just over 7% on the U74 and just over 4% on the C910. Signed-off-by: Anton Blanchard <antonb@tenstorrent.com> Signed-off-by: Cyril Bur <cyrilbur@tenstorrent.com> Tested-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Jisheng Zhang <jszhang@kernel.org> Link: https://lore.kernel.org/r/20240607061335.2197383-1-cyrilbur@tenstorrent.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-24riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTTYunhui Cui
Before cacheinfo can be built correctly, we need to initialize level and type. Since RISC-V currently does not have a register group that describes cache-related attributes like ARM64, we cannot obtain them directly, so now we obtain cache leaves from the ACPI PPTT table (acpi_get_cache_info()) and set the cache type through split_levels. Suggested-by: Jeremy Linton <jeremy.linton@arm.com> Suggested-by: Sudeep Holla <sudeep.holla@arm.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Sunil V L <sunilvl@ventanamicro.com> Reviewed-by: Jeremy Linton <jeremy.linton@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> Link: https://lore.kernel.org/r/20240617131425.7526-2-cuiyunhui@bytedance.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-24riscv: cacheinfo: remove the useless input parameter (node) of ci_leaf_init()Yunhui Cui
ci_leaf_init() is a declared static function. The implementation of the function body and the caller do not use the parameter (struct device_node *node) input parameter, so remove it. Fixes: 6a24915145c9 ("Revert "riscv: Set more data to cacheinfo"") Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> Reviewed-by: Jeremy Linton <jeremy.linton@arm.com> Reviewed-by: Sudeep Holla <sudeep.holla@arm.com> Link: https://lore.kernel.org/r/20240617131425.7526-1-cuiyunhui@bytedance.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>