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2024-07-31riscv: cpufeature: Do not drop Linux-internal extensionsSamuel Holland1-8/+6
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 <[email protected]> Reviewed-by: Andrew Jones <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-26RISC-V: Provide the frequency of time CSR via hwprobePalmer Dabbelt1-0/+5
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 <[email protected]> Reviewed-by: Evan Green <[email protected]> Reviewed-by: Anup Patel <[email protected]> Acked-by: Punit Agrawal <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-26Merge patch series "RISC-V: Select ACPI PPTT drivers"Palmer Dabbelt1-7/+28
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/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-26Merge patch "Enable SPCR table for console output on RISC-V"Palmer Dabbelt1-1/+11
Sia Jee Heng <[email protected]> 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/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-26riscv: enable HAVE_ARCH_STACKLEAKJisheng Zhang1-0/+4
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 <[email protected]> Reviewed-by: Charlie Jenkins <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-26riscv: signal: Remove unlikely() from WARN_ON() conditionZhongqiu Han1-1/+1
"WARN_ON(unlikely(x))" is excessive. WARN_ON() already uses unlikely() internally. Signed-off-by: Zhongqiu Han <[email protected]> Reviewed-by: Bjorn Andersson <[email protected]> Reviewed-by: Andy Chiu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-26riscv: Improve exception and system call latencyAnton Blanchard2-9/+12
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 <[email protected]> Signed-off-by: Cyril Bur <[email protected]> Tested-by: Jisheng Zhang <[email protected]> Reviewed-by: Jisheng Zhang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-24riscv: cacheinfo: initialize cacheinfo's level and type from ACPI PPTTYunhui Cui1-0/+22
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 <[email protected]> Suggested-by: Sudeep Holla <[email protected]> Reviewed-by: Conor Dooley <[email protected]> Reviewed-by: Sunil V L <[email protected]> Reviewed-by: Jeremy Linton <[email protected]> Reviewed-by: Sudeep Holla <[email protected]> Signed-off-by: Yunhui Cui <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-24riscv: cacheinfo: remove the useless input parameter (node) of ci_leaf_init()Yunhui Cui1-7/+6
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 <[email protected]> Reviewed-by: Jeremy Linton <[email protected]> Reviewed-by: Sudeep Holla <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-24RISC-V: ACPI: Enable SPCR table for console output on RISC-VSia Jee Heng1-1/+11
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. Signed-off-by: Sia Jee Heng <[email protected]> Reviewed-by: Sunil V L <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-24trace: riscv: Remove deprecated kprobe on ftrace supportJinjie Ruan2-66/+0
Since commit 7caa9765465f60 ("ftrace: riscv: move from REGS to ARGS"), kprobe on ftrace is not supported by riscv, because riscv's support for FTRACE_WITH_REGS has been replaced with support for FTRACE_WITH_ARGS, and KPROBES_ON_FTRACE will be supplanted by FPROBES. So remove the deprecated kprobe on ftrace support, which is misunderstood. Signed-off-by: Jinjie Ruan <[email protected]> Acked-by: Masami Hiramatsu (Google) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-22Merge patch series "riscv: Separate vendor extensions from standard extensions"Palmer Dabbelt6-43/+214
Charlie Jenkins <[email protected]> says: All extensions, both standard and vendor, live in one struct "riscv_isa_ext". There is currently one vendor extension, xandespmu, but it is likely that more vendor extensions will be added to the kernel in the future. As more vendor extensions (and standard extensions) are added, riscv_isa_ext will become more bloated with a mix of vendor and standard extensions. This also allows each vendor to be conditionally enabled through Kconfig. * b4-shazam-merge: riscv: cpufeature: Extract common elements from extension checking riscv: Introduce vendor variants of extension helpers riscv: Add vendor extensions to /proc/cpuinfo riscv: Extend cpufeature.c to detect vendor extensions Link: https://lore.kernel.org/r/20240719-support_vendor_extensions-v3-0-0af7587bbec0@rivosinc.com Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-22riscv: Add vendor extensions to /proc/cpuinfoCharlie Jenkins1-3/+32
All of the supported vendor extensions that have been listed in riscv_isa_vendor_ext_list can be exported through /proc/cpuinfo. Signed-off-by: Charlie Jenkins <[email protected]> Reviewed-by: Evan Green <[email protected]> Reviewed-by: Conor Dooley <[email protected]> Link: https://lore.kernel.org/r/20240719-support_vendor_extensions-v3-2-0af7587bbec0@rivosinc.com Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-22riscv: Extend cpufeature.c to detect vendor extensionsCharlie Jenkins5-40/+182
Instead of grouping all vendor extensions into the same riscv_isa_ext that standard instructions use, create a struct "riscv_isa_vendor_ext_data_list" that allows each vendor to maintain their vendor extensions independently of the standard extensions. xandespmu is currently the only vendor extension so that is the only extension that is affected by this change. An additional benefit of this is that the extensions of each vendor can be conditionally enabled. A config RISCV_ISA_VENDOR_EXT_ANDES has been added to allow for that. Signed-off-by: Charlie Jenkins <[email protected]> Reviewed-by: Conor Dooley <[email protected]> Reviewed-by: Andy Chiu <[email protected]> Tested-by: Yu Chien Peter Lin <[email protected]> Reviewed-by: Yu Chien Peter Lin <[email protected]> Link: https://lore.kernel.org/r/20240719-support_vendor_extensions-v3-1-0af7587bbec0@rivosinc.com Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-22RISC-V: hwprobe: sort EXT_KEY()s in hwprobe_isa_ext0() alphabeticallyConor Dooley1-22/+21
Currently the entries appear to be in a random order (although according to Palmer he has tried to sort them by key value) which makes it harder to find entries in a growing list, and more likely to have conflicts as all patches are adding to the end of the list. Sort them alphabetically instead. Signed-off-by: Conor Dooley <[email protected]> Reviewed-by: Clément Léger <[email protected]> Link: https://lore.kernel.org/r/20240717-dedicate-squeamish-7e4ab54df58f@spud Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-22Merge patch series "Add ACPI NUMA support for RISC-V"Palmer Dabbelt5-8/+135
Haibo Xu <[email protected]> says: This patch series enable RISC-V ACPI NUMA support which was based on the recently approved ACPI ECR[1]. Patch 1/4 add RISC-V specific acpi_numa.c file to parse NUMA information from SRAT and SLIT ACPI tables. Patch 2/4 add the common SRAT RINTC affinity structure handler. Patch 3/4 change the ACPI_NUMA to a hidden option since it would be selected by default on all supported platform. Patch 4/4 replace pr_info with pr_debug in arch_acpi_numa_init() to avoid potential boot noise on ACPI platforms that are not NUMA. Based-on: https://github.com/linux-riscv/linux-riscv/tree/for-next [1] https://drive.google.com/file/d/1YTdDx2IPm5IeZjAW932EYU-tUtgS08tX/view?usp=sharing Testing: Since the ACPI AIA/PLIC support patch set is still under upstream review, hence it is tested using the poll based HVC SBI console and RAM disk. 1) Build latest Qemu with the following patch backported https://github.com/vlsunil/qemu/commit/42bd4eeefd5d4410a68f02d54fee406d8a1269b0 2) Build latest EDK-II https://github.com/tianocore/edk2/blob/master/OvmfPkg/RiscVVirt/README.md 3) Build Linux with the following configs enabled CONFIG_RISCV_SBI_V01=y CONFIG_SERIAL_EARLYCON_RISCV_SBI=y CONFIG_NONPORTABLE=y CONFIG_HVC_RISCV_SBI=y CONFIG_NUMA=y CONFIG_ACPI_NUMA=y 4) Build buildroot rootfs.cpio 5) Launch the Qemu machine qemu-system-riscv64 -nographic \ -machine virt,pflash0=pflash0,pflash1=pflash1 -smp 4 -m 8G \ -blockdev node-name=pflash0,driver=file,read-only=on,filename=RISCV_VIRT_CODE.fd \ -blockdev node-name=pflash1,driver=file,filename=RISCV_VIRT_VARS.fd \ -object memory-backend-ram,size=4G,id=m0 \ -object memory-backend-ram,size=4G,id=m1 \ -numa node,memdev=m0,cpus=0-1,nodeid=0 \ -numa node,memdev=m1,cpus=2-3,nodeid=1 \ -numa dist,src=0,dst=1,val=30 \ -kernel linux/arch/riscv/boot/Image \ -initrd buildroot/output/images/rootfs.cpio \ -append "root=/dev/ram ro console=hvc0 earlycon=sbi" [ 0.000000] ACPI: SRAT: Node 0 PXM 0 [mem 0x80000000-0x17fffffff] [ 0.000000] ACPI: SRAT: Node 1 PXM 1 [mem 0x180000000-0x27fffffff] [ 0.000000] NUMA: NODE_DATA [mem 0x17fe3bc40-0x17fe3cfff] [ 0.000000] NUMA: NODE_DATA [mem 0x27fff4c40-0x27fff5fff] ... [ 0.000000] ACPI: NUMA: SRAT: PXM 0 -> HARTID 0x0 -> Node 0 [ 0.000000] ACPI: NUMA: SRAT: PXM 0 -> HARTID 0x1 -> Node 0 [ 0.000000] ACPI: NUMA: SRAT: PXM 1 -> HARTID 0x2 -> Node 1 [ 0.000000] ACPI: NUMA: SRAT: PXM 1 -> HARTID 0x3 -> Node 1 * b4-shazam-merge: ACPI: NUMA: replace pr_info with pr_debug in arch_acpi_numa_init ACPI: NUMA: change the ACPI_NUMA to a hidden option ACPI: NUMA: Add handler for SRAT RINTC affinity structure ACPI: RISCV: Add NUMA support based on SRAT and SLIT Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-22ACPI: RISCV: Add NUMA support based on SRAT and SLITHaibo Xu5-8/+135
Add acpi_numa.c file to enable parse NUMA information from ACPI SRAT and SLIT tables. SRAT table provide CPUs(Hart) and memory nodes to proximity domain mapping, while SLIT table provide the distance metrics between proximity domains. Signed-off-by: Haibo Xu <[email protected]> Reviewed-by: Sunil V L <[email protected]> Reviewed-by: Hanjun Guo <[email protected]> Link: https://lore.kernel.org/r/65dbad1fda08a32922c44886e4581e49b4a2fecc.1718268003.git.haibo1.xu@intel.com Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-20Merge tag 'riscv-for-linus-6.11-mw1' of ↵Linus Torvalds9-153/+353
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for various new ISA extensions: * The Zve32[xf] and Zve64[xfd] sub-extensios of the vector extension * Zimop and Zcmop for may-be-operations * The Zca, Zcf, Zcd and Zcb sub-extensions of the C extension * Zawrs - riscv,cpu-intc is now dtschema - A handful of performance improvements and cleanups to text patching - Support for memory hot{,un}plug - The highest user-allocatable virtual address is now visible in hwprobe * tag 'riscv-for-linus-6.11-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (58 commits) riscv: lib: relax assembly constraints in hweight riscv: set trap vector earlier KVM: riscv: selftests: Add Zawrs extension to get-reg-list test KVM: riscv: Support guest wrs.nto riscv: hwprobe: export Zawrs ISA extension riscv: Add Zawrs support for spinlocks dt-bindings: riscv: Add Zawrs ISA extension description riscv: Provide a definition for 'pause' riscv: hwprobe: export highest virtual userspace address riscv: Improve sbi_ecall() code generation by reordering arguments riscv: Add tracepoints for SBI calls and returns riscv: Optimize crc32 with Zbc extension riscv: Enable DAX VMEMMAP optimization riscv: mm: Add support for ZONE_DEVICE virtio-mem: Enable virtio-mem for RISC-V riscv: Enable memory hotplugging for RISC-V riscv: mm: Take memory hotplug read-lock during kernel page table dump riscv: mm: Add memory hotplugging support riscv: mm: Add pfn_to_kaddr() implementation riscv: mm: Refactor create_linear_mapping_range() for memory hot add ...
2024-07-16Merge tag 'asm-generic-6.11' of ↵Linus Torvalds3-4/+12
git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic Pull asm-generic updates from Arnd Bergmann: "Most of this is part of my ongoing work to clean up the system call tables. In this bit, all of the newer architectures are converted to use the machine readable syscall.tbl format instead in place of complex macros in include/uapi/asm-generic/unistd.h. This follows an earlier series that fixed various API mismatches and in turn is used as the base for planned simplifications. The other two patches are dead code removal and a warning fix" * tag 'asm-generic-6.11' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: vmlinux.lds.h: catch .bss..L* sections into BSS") fixmap: Remove unused set_fixmap_offset_io() riscv: convert to generic syscall table openrisc: convert to generic syscall table nios2: convert to generic syscall table loongarch: convert to generic syscall table hexagon: use new system call table csky: convert to generic syscall table arm64: rework compat syscall macros arm64: generate 64-bit syscall.tbl arm64: convert unistd_32.h to syscall.tbl format arc: convert to generic syscall table clone3: drop __ARCH_WANT_SYS_CLONE3 macro kbuild: add syscall table generation to scripts/Makefile.asm-headers kbuild: verify asm-generic header list loongarch: avoid generating extra header files um: don't generate asm/bpf_perf_event.h csky: drop asm/gpio.h wrapper syscalls: add generic scripts/syscall.tbl
2024-07-12riscv: set trap vector earlieryang.zhang1-0/+3
The exception vector of the booting hart is not set before enabling the mmu and then still points to the value of the previous firmware, typically _start. That makes it hard to debug setup_vm() when bad things happen. So fix that by setting the exception vector earlier. Reviewed-by: Alexandre Ghiti <[email protected]> Signed-off-by: yang.zhang <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-12Merge patch series "riscv: Apply Zawrs when available"Palmer Dabbelt2-0/+2
Andrew Jones <[email protected]> says: Zawrs provides two instructions (wrs.nto and wrs.sto), where both are meant to allow the hart to enter a low-power state while waiting on a store to a memory location. The instructions also both wait an implementation-defined "short" duration (unless the implementation terminates the stall for another reason). The difference is that while wrs.sto will terminate when the duration elapses, wrs.nto, depending on configuration, will either just keep waiting or an ILL exception will be raised. Linux will use wrs.nto, so if platforms have an implementation which falls in the "just keep waiting" category (which is not expected), then it should _not_ advertise Zawrs in the hardware description. Like wfi (and with the same {m,h}status bits to configure it), when wrs.nto is configured to raise exceptions it's expected that the higher privilege level will see the instruction was a wait instruction, do something, and then resume execution following the instruction. For example, KVM does configure exceptions for wfi (hstatus.VTW=1) and therefore also for wrs.nto. KVM does this for wfi since it's better to allow other tasks to be scheduled while a VCPU waits for an interrupt. For waits such as those where wrs.nto/sto would be used, which are typically locks, it is also a good idea for KVM to be involved, as it can attempt to schedule the lock holding VCPU. This series starts with Christoph's addition of the riscv smp_cond_load_relaxed function which applies wrs.sto when available. That patch has been reworked to use wrs.nto and to use the same approach as Arm for the wait loop, since we can't have arbitrary C code between the load-reserved and the wrs. Then, hwprobe support is added (since the instructions are also usable from usermode), and finally KVM is taught about wrs.nto, allowing guests to see and use the Zawrs extension. We still don't have test results from hardware, and it's not possible to prove that using Zawrs is a win when testing on QEMU, not even when oversubscribing VCPUs to guests. However, it is possible to use KVM selftests to force a scenario where we can prove Zawrs does its job and does it well. [4] is a test which does this and, on my machine, without Zawrs it takes 16 seconds to complete and with Zawrs it takes 0.25 seconds. This series is also available here [1]. In order to use QEMU for testing a build with [2] is needed. In order to enable guests to use Zawrs with KVM using kvmtool, the branch at [3] may be used. [1] https://github.com/jones-drew/linux/commits/riscv/zawrs-v3/ [2] https://lore.kernel.org/all/[email protected]/ [3] https://github.com/jones-drew/kvmtool/commits/riscv/zawrs/ [4] https://github.com/jones-drew/linux/commit/cb2beccebcece10881db842ed69bdd5715cfab5d Link: https://lore.kernel.org/r/[email protected] * b4-shazam-merge: KVM: riscv: selftests: Add Zawrs extension to get-reg-list test KVM: riscv: Support guest wrs.nto riscv: hwprobe: export Zawrs ISA extension riscv: Add Zawrs support for spinlocks dt-bindings: riscv: Add Zawrs ISA extension description riscv: Provide a definition for 'pause' Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-12riscv: hwprobe: export Zawrs ISA extensionAndrew Jones1-0/+1
Export Zawrs ISA extension through hwprobe. [Palmer: there's a gap in the numbers here as there will be a merge conflict when this is picked up. To avoid confusion I just set the hwprobe ID to match what it would be post-merge.] Signed-off-by: Andrew Jones <[email protected]> Reviewed-by: Clément Léger <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-12riscv: Add Zawrs support for spinlocksChristoph Müllner1-0/+1
RISC-V code uses the generic ticket lock implementation, which calls the macros smp_cond_load_relaxed() and smp_cond_load_acquire(). Introduce a RISC-V specific implementation of smp_cond_load_relaxed() which applies WRS.NTO of the Zawrs extension in order to reduce power consumption while waiting and allows hypervisors to enable guests to trap while waiting. smp_cond_load_acquire() doesn't need a RISC-V specific implementation as the generic implementation is based on smp_cond_load_relaxed() and smp_acquire__after_ctrl_dep() sufficiently provides the acquire semantics. This implementation is heavily based on Arm's approach which is the approach Andrea Parri also suggested. The Zawrs specification can be found here: https://github.com/riscv/riscv-zawrs/blob/main/zawrs.adoc Signed-off-by: Christoph Müllner <[email protected]> Co-developed-by: Andrew Jones <[email protected]> Signed-off-by: Andrew Jones <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-11riscv: hwprobe: export highest virtual userspace addressClément Léger1-0/+4
Some userspace applications (OpenJDK for instance) uses the free MSBs in pointers to insert additional information for their own logic and need to get this information from somewhere. Currently they rely on parsing /proc/cpuinfo "mmu=svxx" string to obtain the current value of virtual address usable bits [1]. Since this reflect the raw supported MMU mode, it might differ from the logical one used internally which is why arch_get_mmap_end() is used. Exporting the highest mmapable address through hwprobe will allow a more stable interface to be used. For that purpose, add a new hwprobe key named RISCV_HWPROBE_KEY_HIGHEST_VIRT_ADDRESS which will export the highest userspace virtual address. Link: https://github.com/openjdk/jdk/blob/master/src/hotspot/os_cpu/linux_riscv/vm_version_linux_riscv.cpp#L171 [1] Signed-off-by: Clément Léger <[email protected]> Reviewed-by: Charlie Jenkins <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-10riscv: Improve sbi_ecall() code generation by reordering argumentsAlexandre Ghiti1-5/+5
The sbi_ecall() function arguments are not in the same order as the ecall arguments, so we end up re-ordering the registers before the ecall which is useless and costly. So simply reorder the arguments in the same way as expected by ecall. Instead of reordering directly the arguments of sbi_ecall(), use a proxy macro since the current ordering is more natural. Before: Dump of assembler code for function sbi_ecall: 0xffffffff800085e0 <+0>: add sp,sp,-32 0xffffffff800085e2 <+2>: sd s0,24(sp) 0xffffffff800085e4 <+4>: mv t1,a0 0xffffffff800085e6 <+6>: add s0,sp,32 0xffffffff800085e8 <+8>: mv t3,a1 0xffffffff800085ea <+10>: mv a0,a2 0xffffffff800085ec <+12>: mv a1,a3 0xffffffff800085ee <+14>: mv a2,a4 0xffffffff800085f0 <+16>: mv a3,a5 0xffffffff800085f2 <+18>: mv a4,a6 0xffffffff800085f4 <+20>: mv a5,a7 0xffffffff800085f6 <+22>: mv a6,t3 0xffffffff800085f8 <+24>: mv a7,t1 0xffffffff800085fa <+26>: ecall 0xffffffff800085fe <+30>: ld s0,24(sp) 0xffffffff80008600 <+32>: add sp,sp,32 0xffffffff80008602 <+34>: ret After: Dump of assembler code for function __sbi_ecall: 0xffffffff8000b6b2 <+0>: add sp,sp,-32 0xffffffff8000b6b4 <+2>: sd s0,24(sp) 0xffffffff8000b6b6 <+4>: add s0,sp,32 0xffffffff8000b6b8 <+6>: ecall 0xffffffff8000b6bc <+10>: ld s0,24(sp) 0xffffffff8000b6be <+12>: add sp,sp,32 0xffffffff8000b6c0 <+14>: ret Signed-off-by: Alexandre Ghiti <[email protected]> Reviewed-by: Atish Patra <[email protected]> Reviewed-by: Yunhui Cui <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-10riscv: Add tracepoints for SBI calls and returnsSamuel Holland1-0/+7
These are useful for measuring the latency of SBI calls. The SBI HSM extension is excluded because those functions are called from contexts such as cpuidle where instrumentation is not allowed. Reviewed-by: Andrew Jones <[email protected]> Signed-off-by: Samuel Holland <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-10riscv: convert to generic syscall tableArnd Bergmann3-4/+12
The uapi/asm/unistd_{32,64}.h and asm/syscall_table_{32,64}.h headers can now be generated from scripts/syscall.tbl, which makes this consistent with the other architectures that have their own syscall.tbl. riscv has two extra system call that gets added to scripts/syscall.tbl. The newstat and rlimit entries in the syscall_abis_64 line are for system calls that were part of the generic ABI when riscv64 got added but are no longer enabled by default for new architectures. Both riscv32 and riscv64 also implement memfd_secret, which is optional for all architectures. Unlike all the other 32-bit architectures, the time32 and stat64 sets of syscalls are not enabled on riscv32. Both the user visible side of asm/unistd.h and the internal syscall table in the kernel should have the same effective contents after this. Signed-off-by: Arnd Bergmann <[email protected]>
2024-07-03riscv: kexec: Avoid deadlock in kexec crash pathSong Shuai1-9/+1
If the kexec crash code is called in the interrupt context, the machine_kexec_mask_interrupts() function will trigger a deadlock while trying to acquire the irqdesc spinlock and then deactivate irqchip in irq_set_irqchip_state() function. Unlike arm64, riscv only requires irq_eoi handler to complete EOI and keeping irq_set_irqchip_state() will only leave this possible deadlock without any use. So we simply remove it. Link: https://lore.kernel.org/linux-riscv/[email protected]/ Fixes: b17d19a5314a ("riscv: kexec: Fixup irq controller broken in kexec crash path") Signed-off-by: Song Shuai <[email protected]> Reviewed-by: Ryo Takakura <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-07-03riscv: stacktrace: fix usage of ftrace_graph_ret_addr()Puranjay Mohan1-1/+2
ftrace_graph_ret_addr() takes an `idx` integer pointer that is used to optimize the stack unwinding. Pass it a valid pointer to utilize the optimizations that might be available in the future. The commit is making riscv's usage of ftrace_graph_ret_addr() match x86_64. Signed-off-by: Puranjay Mohan <[email protected]> Reviewed-by: Steven Rostedt (Google) <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-28Merge tag 'riscv-for-linus-6.10-rc6' of ↵Linus Torvalds3-14/+21
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: - A fix for vector load/store instruction decoding, which could result in reserved vector element length encodings decoding as valid vector instructions. - Instruction patching now aggressively flushes the local instruction cache, to avoid situations where patching functions on the flush path results in torn instructions being fetched. - A fix to prevent the stack walker from showing up as part of traces. * tag 'riscv-for-linus-6.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: stacktrace: convert arch_stack_walk() to noinstr riscv: patch: Flush the icache right after patching to avoid illegal insns RISC-V: fix vector insn load/store width mask
2024-06-26Merge patch series "Add support for a few Zc* extensions, Zcmop and Zimop"Palmer Dabbelt2-86/+197
Clément Léger <[email protected]> says: Add support for (yet again) more RVA23U64 missing extensions. Add support for Zimop, Zcmop, Zca, Zcf, Zcd and Zcb extensions ISA string parsing, hwprobe and kvm support. Zce, Zcmt and Zcmp extensions have been left out since they target microcontrollers/embedded CPUs and are not needed by RVA23U64. Since Zc* extensions states that C implies Zca, Zcf (if F and RV32), Zcd (if D), this series modifies the way ISA string is parsed and now does it in two phases. First one parses the string and the second one validates it for the final ISA description. * b4-shazam-merge: KVM: riscv: selftests: Add Zcmop extension to get-reg-list test RISC-V: KVM: Allow Zcmop extension for Guest/VM riscv: hwprobe: export Zcmop ISA extension riscv: add ISA extension parsing for Zcmop dt-bindings: riscv: add Zcmop ISA extension description KVM: riscv: selftests: Add some Zc* extensions to get-reg-list test RISC-V: KVM: Allow Zca, Zcf, Zcd and Zcb extensions for Guest/VM riscv: hwprobe: export Zca, Zcf, Zcd and Zcb ISA extensions riscv: add ISA parsing for Zca, Zcf, Zcd and Zcb riscv: add ISA extensions validation callback dt-bindings: riscv: add Zca, Zcf, Zcd and Zcb ISA extension description KVM: riscv: selftests: Add Zimop extension to get-reg-list test RISC-V: KVM: Allow Zimop extension for Guest/VM riscv: hwprobe: export Zimop ISA extension riscv: add ISA extension parsing for Zimop dt-bindings: riscv: add Zimop ISA extension description Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: hwprobe: export Zcmop ISA extensionClément Léger1-0/+1
Export Zcmop ISA extension through hwprobe. Signed-off-by: Clément Léger <[email protected]> Reviewed-by: Evan Green <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: add ISA extension parsing for ZcmopClément Léger1-0/+1
Add parsing for Zcmop ISA extension which was ratified in commit c732a4f39a4c ("Zcmop is ratified/1.0") of the riscv-isa-manual. Signed-off-by: Clément Léger <[email protected]> Reviewed-by: Conor Dooley <[email protected]> Reviewed-by: Charlie Jenkins <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: hwprobe: export Zca, Zcf, Zcd and Zcb ISA extensionsClément Léger1-0/+4
Export Zca, Zcf, Zcd and Zcb ISA extension through hwprobe. Signed-off-by: Clément Léger <[email protected]> Reviewed-by: Charlie Jenkins <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: add ISA parsing for Zca, Zcf, Zcd and ZcbClément Léger1-1/+54
The Zc* standard extension for code reduction introduces new extensions. This patch adds support for Zca, Zcf, Zcd and Zcb. Zce, Zcmt and Zcmp are left out of this patch since they are targeting microcontrollers/ embedded CPUs instead of application processors. Signed-off-by: Clément Léger <[email protected]> Reviewed-by: Conor Dooley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: add ISA extensions validation callbackClément Léger1-85/+135
Since a few extensions (Zicbom/Zicboz) already needs validation and future ones will need it as well (Zc*) add a validate() callback to struct riscv_isa_ext_data. This require to rework the way extensions are parsed and split it in two phases. First phase is isa string or isa extension list parsing and consists in enabling all the extensions in a temporary bitmask (source isa) without any validation. The second step "resolves" the final isa bitmap, handling potential missing dependencies. The mechanism is quite simple and simply validate each extension described in the source bitmap before enabling it in the resolved isa bitmap. validate() callbacks can return either 0 for success, -EPROBEDEFER if extension needs to be validated again at next loop. A previous ISA bitmap is kept to avoid looping multiple times if an extension dependencies are never satisfied until we reach a stable state. In order to avoid any potential infinite looping, allow looping a maximum of the number of extension we handle. Zicboz and Zicbom extensions are modified to use this validation mechanism. Signed-off-by: Clément Léger <[email protected]> Reviewed-by: Conor Dooley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: hwprobe: export Zimop ISA extensionClément Léger1-0/+1
Export Zimop ISA extension through hwprobe. Signed-off-by: Clément Léger <[email protected]> Reviewed-by: Charlie Jenkins <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: add ISA extension parsing for ZimopClément Léger1-0/+1
Add parsing for Zimop ISA extension which was ratified in commit 58220614a5f of the riscv-isa-manual. Signed-off-by: Clément Léger <[email protected]> Reviewed-by: Charlie Jenkins <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26Merge patch "riscv: stacktrace: convert arch_stack_walk() to noinstr"Palmer Dabbelt1-1/+1
This first patch in the larger series is a fix, so I'm merging it into fixes while the rest of the patch set is still under development. * b4-shazam-merge: riscv: stacktrace: convert arch_stack_walk() to noinstr Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: stacktrace: convert arch_stack_walk() to noinstrAndy Chiu1-1/+1
arch_stack_walk() is called intensively in function_graph when the kernel is compiled with CONFIG_TRACE_IRQFLAGS. As a result, the kernel logs a lot of arch_stack_walk and its sub-functions into the ftrace buffer. However, these functions should not appear on the trace log because they are part of the ftrace itself. This patch references what arm64 does for the smae function. So it further prevent the re-enter kprobe issue, which is also possible on riscv. Related-to: commit 0fbcd8abf337 ("arm64: Prohibit instrumentation on arch_stack_walk()") Fixes: 680341382da5 ("riscv: add CALLER_ADDRx support") Signed-off-by: Andy Chiu <[email protected]> Reviewed-by: Alexandre Ghiti <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: patch: Flush the icache right after patching to avoid illegal insnsAlexandre Ghiti2-13/+20
We cannot delay the icache flush after patching some functions as we may have patched a function that will get called before the icache flush. The only way to completely avoid such scenario is by flushing the icache as soon as we patch a function. This will probably be costly as we don't batch the icache maintenance anymore. Fixes: 6ca445d8af0e ("riscv: Fix early ftrace nop patching") Reported-by: Conor Dooley <[email protected]> Closes: https://lore.kernel.org/linux-riscv/20240613-lubricant-breath-061192a9489a@wendy/ Signed-off-by: Alexandre Ghiti <[email protected]> Reviewed-by: Andy Chiu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26Merge patch series "riscv: Various text patching improvements"Palmer Dabbelt3-49/+55
Samuel Holland <[email protected]> says: Here are a few changes to minimize calls to stop_machine() and flush_icache_*() in the various text patching functions, as well as to simplify the code. * b4-shazam-merge: riscv: Remove extra variable in patch_text_nosync() riscv: Use offset_in_page() in text patching functions riscv: Pass patch_text() the length in bytes riscv: Simplify text patching loops riscv: kprobes: Use patch_text_nosync() for insn slots riscv: jump_label: Simplify assembly syntax riscv: jump_label: Batch icache maintenance Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: Remove extra variable in patch_text_nosync()Samuel Holland1-8/+4
This cast is superfluous, and is incorrect anyway if compressed instructions may be present. Reviewed-by: Björn Töpel <[email protected]> Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Conor Dooley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: Use offset_in_page() in text patching functionsSamuel Holland1-3/+3
This is a bit easier to parse than the equivalent bit manipulation. Reviewed-by: Björn Töpel <[email protected]> Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Conor Dooley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: Pass patch_text() the length in bytesSamuel Holland2-17/+15
patch_text_nosync() already handles an arbitrary length of code, so this removes a superfluous loop and reduces the number of icache flushes. Reviewed-by: Björn Töpel <[email protected]> Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Conor Dooley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: Simplify text patching loopsSamuel Holland1-16/+21
This reduces the number of variables and makes the code easier to parse. Signed-off-by: Samuel Holland <[email protected]> Reviewed-by: Björn Töpel <[email protected]> Reviewed-by: Conor Dooley <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: kprobes: Use patch_text_nosync() for insn slotsSamuel Holland1-3/+2
These instructions are not yet visible to the rest of the system, so there is no need to do the whole stop_machine() dance. Reviewed-by: Björn Töpel <[email protected]> Signed-off-by: Samuel Holland <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-26riscv: jump_label: Batch icache maintenanceSamuel Holland1-4/+12
Switch to the batched version of the jump label update functions so instruction cache maintenance is deferred until the end of the update. Reviewed-by: Björn Töpel <[email protected]> Signed-off-by: Samuel Holland <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>
2024-06-25syscalls: mmap(): use unsigned offset type consistentlyArnd Bergmann1-2/+2
Most architectures that implement the old-style mmap() with byte offset use 'unsigned long' as the type for that offset, but microblaze and riscv have the off_t type that is shared with userspace, matching the prototype in include/asm-generic/syscalls.h. Make this consistent by using an unsigned argument everywhere. This changes the behavior slightly, as the argument is shifted to a page number, and an user input with the top bit set would result in a negative page offset rather than a large one as we use elsewhere. For riscv, the 32-bit sys_mmap2() definition actually used a custom type that is different from the global declaration, but this was missed due to an incorrect type check. Signed-off-by: Arnd Bergmann <[email protected]>
2024-05-30riscv: vector: adjust minimum Vector requirement to ZVE32XAndy Chiu3-3/+13
Make has_vector() to check for ZVE32X. Every in-kernel usage of V that requires a more complicate version of V must then call out explicitly. Also, change riscv_v_first_use_handler(), and boot code that calls riscv_v_setup_vsize() to accept ZVE32X. Most kernel/user interfaces requires minimum of ZVE32X. Thus, programs compiled and run with ZVE32X should be supported by the kernel on most aspects. This includes context-switch, signal, ptrace, prctl, and hwprobe. One exception is that ELF_HWCAP returns 'V' only if full V is supported on the platform. This means that the system without a full V must not rely on ELF_HWCAP to tell whether it is allowable to execute Vector without first invoking a prctl() check. Signed-off-by: Andy Chiu <[email protected]> Acked-by: Joel Granados <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Palmer Dabbelt <[email protected]>