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2025-03-19riscv: hwprobe: export Zaamo and Zalrsc extensionsClément Léger
Export the Zaamo and Zalrsc extensions to userspace using hwprobe. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240619153913.867263-4-cleger@rivosinc.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
2025-03-18RISC-V: hwprobe: Expose Zicbom extension and its block sizeYunhui Cui
Expose Zicbom through hwprobe and also provide a key to extract its respective block size. [ alex: Fix merge conflicts and hwprobe numbering ] Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Signed-off-by: Yunhui Cui <cuiyunhui@bytedance.com> Link: https://lore.kernel.org/r/20250226063206.71216-3-cuiyunhui@bytedance.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
2025-03-18Merge patch series "riscv: Add bfloat16 instruction support"Alexandre Ghiti
Inochi Amaoto <inochiama@gmail.com> says: Add description for the BFloat16 precision Floating-Point ISA extension, (Zfbfmin, Zvfbfmin, Zvfbfwma). which was ratified in commit 4dc23d62 ("Added Chapter title to BF16") of the riscv-isa-manual. * patches from https://lore.kernel.org/r/20250213003849.147358-1-inochiama@gmail.com: riscv: hwprobe: export bfloat16 ISA extension riscv: add ISA extension parsing for bfloat16 ISA extension dt-bindings: riscv: add bfloat16 ISA extension description Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20250213003849.147358-1-inochiama@gmail.com
2025-03-18riscv: hwprobe: export bfloat16 ISA extensionInochi Amaoto
Export Zfbmin, Zvfbfmin, Zvfbfwma ISA extension through hwprobe. Signed-off-by: Inochi Amaoto <inochiama@gmail.com> Reviewed-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20250213003849.147358-4-inochiama@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
2025-03-18riscv: hwprobe: export Zicntr and Zihpm extensionsMiquel Sabaté Solà
Export Zicntr and Zihpm ISA extensions through the hwprobe syscall. [ alex: Fix hwprobe numbering ] Signed-off-by: Miquel Sabaté Solà <mikisabate@gmail.com> Acked-by: Jesse Taube <jesse@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20240913051324.8176-1-mikisabate@gmail.com Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
2025-01-18riscv: hwprobe: Add thead vendor extension probingCharlie Jenkins
Add a new hwprobe key "RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0" which allows userspace to probe for the new RISCV_ISA_VENDOR_EXT_XTHEADVECTOR vendor extension. This new key will allow userspace code to probe for which thead vendor extensions are supported. This API is modeled to be consistent with RISCV_HWPROBE_KEY_IMA_EXT_0. The bitmask returned will have each bit corresponding to a supported thead vendor extension of the cpumask set. Just like RISCV_HWPROBE_KEY_IMA_EXT_0, this allows a userspace program to determine all of the supported thead vendor extensions in one call. Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Reviewed-by: Evan Green <evan@rivosinc.com> Tested-by: Yangyu Chen <cyy@cyyself.name> Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-10-236c22791ef9@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-10-24Merge patch series "riscv: Userspace pointer masking and tagged address ABI"Palmer Dabbelt
Samuel Holland <samuel.holland@sifive.com> says: RISC-V defines three extensions for pointer masking[1]: - Smmpm: configured in M-mode, affects M-mode - Smnpm: configured in M-mode, affects the next lower mode (S or U-mode) - Ssnpm: configured in S-mode, affects the next lower mode (VS, VU, or U-mode) This series adds support for configuring Smnpm or Ssnpm (depending on which privilege mode the kernel is running in) to allow pointer masking in userspace (VU or U-mode), extending the PR_SET_TAGGED_ADDR_CTRL API from arm64. Unlike arm64 TBI, userspace pointer masking is not enabled by default on RISC-V. Additionally, the tag width (referred to as PMLEN) is variable, so userspace needs to ask the kernel for a specific tag width, which is interpreted as a lower bound on the number of tag bits. This series also adds support for a tagged address ABI similar to arm64 and x86. Since accesses from the kernel to user memory use the kernel's pointer masking configuration, not the user's, the kernel must untag user pointers in software before dereferencing them. And since the tag width is variable, as with LAM on x86, it must be kept the same across all threads in a process so untagged_addr_remote() can work. [1]: https://github.com/riscv/riscv-j-extension/raw/d70011dde6c2/zjpm-spec.pdf * b4-shazam-merge: KVM: riscv: selftests: Add Smnpm and Ssnpm to get-reg-list test RISC-V: KVM: Allow Smnpm and Ssnpm extensions for guests riscv: hwprobe: Export the Supm ISA extension riscv: selftests: Add a pointer masking test riscv: Allow ptrace control of the tagged address ABI riscv: Add support for the tagged address ABI riscv: Add support for userspace pointer masking riscv: Add CSR definitions for pointer masking riscv: Add ISA extension parsing for pointer masking dt-bindings: riscv: Add pointer masking ISA extensions Link: https://lore.kernel.org/r/20241016202814.4061541-1-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-10-24riscv: hwprobe: Export the Supm ISA extensionSamuel Holland
Supm is a virtual ISA extension defined in the RISC-V Pointer Masking specification, which indicates that pointer masking is available in U-mode. It can be provided by either Smnpm or Ssnpm, depending on which mode the kernel runs in. Userspace should not care about this distinction, so export Supm instead of either underlying extension. Hide the extension if the kernel was compiled without support for the pointer masking prctl() interface. Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Link: https://lore.kernel.org/r/20241016202814.4061541-9-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-10-18RISC-V: Detect unaligned vector accesses supportedJesse Taube
Run an unaligned vector access to test if the system supports vector unaligned access. Add the result to a new key in hwprobe. This is useful for usermode to know if vector misaligned accesses are supported and if they are faster or slower than equivalent byte accesses. Signed-off-by: Jesse Taube <jesse@rivosinc.com> Signed-off-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20241017-jesse_unaligned_vector-v10-4-5b33500160f8@rivosinc.com 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>
2024-07-26RISC-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>
2024-07-12Merge patch series "riscv: Apply Zawrs when available"Palmer Dabbelt
Andrew Jones <ajones@ventanamicro.com> 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/20240312152901.512001-2-ajones@ventanamicro.com/ [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/20240426100820.14762-8-ajones@ventanamicro.com * 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 <palmer@rivosinc.com>
2024-07-12riscv: hwprobe: export Zawrs ISA extensionAndrew Jones
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 <ajones@ventanamicro.com> Reviewed-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20240426100820.14762-12-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-07-11riscv: hwprobe: export highest virtual userspace addressClément Léger
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 <cleger@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240410144558.1104006-1-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: hwprobe: export Zcmop ISA extensionClément Léger
Export Zcmop ISA extension through hwprobe. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20240619113529.676940-15-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: hwprobe: export Zca, Zcf, Zcd and Zcb ISA extensionsClément Léger
Export Zca, Zcf, Zcd and Zcb ISA extension through hwprobe. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240619113529.676940-10-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-06-26riscv: hwprobe: export Zimop ISA extensionClément Léger
Export Zimop ISA extension through hwprobe. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Charlie Jenkins <charlie@rivosinc.com> Link: https://lore.kernel.org/r/20240619113529.676940-4-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-30riscv: hwprobe: add zve Vector subextensions into hwprobe interfaceAndy Chiu
The following Vector subextensions for "embedded" platforms are added into RISCV_HWPROBE_KEY_IMA_EXT_0: - ZVE32X - ZVE32F - ZVE64X - ZVE64F - ZVE64D Extensions ending with an X indicates that the platform doesn't have a vector FPU. Extensions ending with F/D mean that whether single (F) or double (D) precision vector operation is supported. The number 32 or 64 follows from ZVE tells the maximum element length. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20240510-zve-detection-v5-6-0711bdd26c12@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-05-22Merge tag 'riscv-for-linus-6.10-mw1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Add byte/half-word compare-and-exchange, emulated via LR/SC loops - Support for Rust - Support for Zihintpause in hwprobe - Add PR_RISCV_SET_ICACHE_FLUSH_CTX prctl() - Support lockless lockrefs * tag 'riscv-for-linus-6.10-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits) riscv: defconfig: Enable CONFIG_CLK_SOPHGO_CV1800 riscv: select ARCH_HAS_FAST_MULTIPLIER riscv: mm: still create swiotlb buffer for kmalloc() bouncing if required riscv: Annotate pgtable_l{4,5}_enabled with __ro_after_init riscv: Remove redundant CONFIG_64BIT from pgtable_l{4,5}_enabled riscv: mm: Always use an ASID to flush mm contexts riscv: mm: Preserve global TLB entries when switching contexts riscv: mm: Make asid_bits a local variable riscv: mm: Use a fixed layout for the MM context ID riscv: mm: Introduce cntx2asid/cntx2version helper macros riscv: Avoid TLB flush loops when affected by SiFive CIP-1200 riscv: Apply SiFive CIP-1200 workaround to single-ASID sfence.vma riscv: mm: Combine the SMP and UP TLB flush code riscv: Only send remote fences when some other CPU is online riscv: mm: Broadcast kernel TLB flushes only when needed riscv: Use IPIs for remote cache/TLB flushes by default riscv: Factor out page table TLB synchronization riscv: Flush the instruction cache during SMP bringup riscv: hwprobe: export Zihintpause ISA extension riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code ...
2024-04-28riscv: hwprobe: export Zihintpause ISA extensionClément Léger
Export the Zihintpause ISA extension through hwprobe which allows using "pause" instructions. Some userspace applications (OpenJDK for instance) uses this to handle some locking back-off. Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20240221083108.1235311-1-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-04-23riscv: hwprobe: fix invalid sign extension for RISCV_HWPROBE_EXT_ZVFHMINClément Léger
The current definition yields a negative 32bits signed value which result in a mask with is obviously incorrect. Replace it by using a 1ULL bit shift value to obtain a single set bit mask. Fixes: 5dadda5e6a59 ("riscv: hwprobe: export Zvfh[min] ISA extensions") Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20240409143839.558784-1-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-09Merge patch series "riscv: hwprobe: add Zicond, Zacas and Ztso support"Palmer Dabbelt
Clément Léger <cleger@rivosinc.com> says: This series add support for a few more extensions that are present in the RVA22U64/RVA23U64 (either mandatory or optional) and that are useful for userspace: - Zicond - Zacas - Ztso Series currently based on riscv/for-next. * b4-shazam-lts: riscv: hwprobe: export Zicond extension riscv: hwprobe: export Zacas ISA extension riscv: add ISA extension parsing for Zacas dt-bindings: riscv: add Zacas ISA extension description riscv: hwprobe: export Ztso ISA extension riscv: add ISA extension parsing for Ztso Link: https://lore.kernel.org/r/20231220155723.684081-1-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-09riscv: hwprobe: export Zicond extensionClément Léger
Export the zicond extension to userspace using hwprobe. Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231220155723.684081-7-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-09riscv: hwprobe: export Zacas ISA extensionClément Léger
Export Zacas ISA extension through hwprobe. Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231220155723.684081-6-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-09riscv: hwprobe: export Ztso ISA extensionClément Léger
Export the Ztso extension to userspace. Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231220155723.684081-3-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-09Merge patch series "RISC-V: hwprobe: Introduce which-cpus"Palmer Dabbelt
Andrew Jones <ajones@ventanamicro.com> says: This series introduces a flag for the hwprobe syscall which effectively reverses its behavior from getting the values of keys for a set of cpus to getting the cpus for a set of key-value pairs. * b4-shazam-merge: RISC-V: selftests: Add which-cpus hwprobe test RISC-V: hwprobe: Introduce which-cpus flag RISC-V: Move the hwprobe syscall to its own file RISC-V: hwprobe: Clarify cpus size parameter Link: https://lore.kernel.org/r/20231122164700.127954-6-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2024-01-03RISC-V: hwprobe: Introduce which-cpus flagAndrew Jones
Introduce the first flag for the hwprobe syscall. The flag basically reverses its behavior, i.e. instead of populating the values of keys for a given set of cpus, the set of cpus after the call is the result of finding a set which supports the values of the keys. In order to do this, we implement a pair compare function which takes the type of value (a single value vs. a bitmask of booleans) into consideration. We also implement vdso support for the new flag. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20231122164700.127954-9-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-12-12riscv: hwprobe: export Zfa ISA extensionClément Léger
Export Zfa ISA extension[1] through hwprobe. Link: https://drive.google.com/file/d/1VT6QIggpb59-8QRV266dEE4T8FZTxGq4/view [1] Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20231114141256.126749-20-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-12-12riscv: hwprobe: export Zvfh[min] ISA extensionsClément Léger
Export Zvfh[min] ISA extension[1] through hwprobe. Link: https://drive.google.com/file/d/1_Yt60HGAf1r1hx7JnsIptw0sqkBd9BQ8/view [1] Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20231114141256.126749-17-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-12-12riscv: hwprobe: export Zhintntl ISA extensionClément Léger
Export Zihintntl extension[1] through hwprobe. Link: https://drive.google.com/file/d/13_wsN8YmRfH8YWysFyTX-DjTkCnBd9hj/view [1] Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20231114141256.126749-14-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-12-12riscv: hwprobe: export Zfh[min] ISA extensionsClément Léger
Export Zfh[min] ISA extensions[1] through hwprobe only if FPU support is available. Link: https://drive.google.com/file/d/1z3tQQLm5ALsAD77PM0l0CHnapxWCeVzP/view [1] Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20231114141256.126749-11-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-12-12riscv: hwprobe: export vector crypto ISA extensionsClément Léger
Export Zv* vector crypto ISA extensions that were added in "RISC-V Cryptography Extensions Volume II" specification[1] through hwprobe. This adds support for the following instructions: - Zvbb: Vector Basic Bit-manipulation - Zvbc: Vector Carryless Multiplication - Zvkb: Vector Cryptography Bit-manipulation - Zvkg: Vector GCM/GMAC. - Zvkned: NIST Suite: Vector AES Block Cipher - Zvknh[ab]: NIST Suite: Vector SHA-2 Secure Hash - Zvksed: ShangMi Suite: SM4 Block Cipher - Zvksh: ShangMi Suite: SM3 Secure Hash - Zvknc: NIST Algorithm Suite with carryless multiply - Zvkng: NIST Algorithm Suite with GCM. - Zvksc: ShangMi Algorithm Suite with carryless multiplication - Zvksg: ShangMi Algorithm Suite with GCM. - Zvkt: Vector Data-Independent Execution Latency. Zvkn and Zvks are ommited since they are a superset of other extensions. Link: https://drive.google.com/file/d/1gb9OLH-DhbCgWp7VwpPOVrrY6f3oSJLL/view [1] Signed-off-by: Clément Léger <cleger@rivosinc.com> Reviewed-by: Evan Green <evan@rivosinc.com> Link: https://lore.kernel.org/r/20231114141256.126749-8-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-12-12riscv: hwprobe: add support for scalar crypto ISA extensionsClément Léger
Export the following scalar crypto extensions through hwprobe: - Zbkb - Zbkc - Zbkx - Zknd - Zkne - Zknh - Zksed - Zksh - Zkt Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231114141256.126749-5-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-12-12riscv: hwprobe: export missing Zbc ISA extensionClément Léger
While Zba and Zbb were exported through hwprobe, Zbc was not. Export it. Signed-off-by: Clément Léger <cleger@rivosinc.com> Link: https://lore.kernel.org/r/20231114141256.126749-3-cleger@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-11-08Merge tag 'riscv-for-linus-6.7-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V updates from Palmer Dabbelt: - Support for cbo.zero in userspace - Support for CBOs on ACPI-based systems - A handful of improvements for the T-Head cache flushing ops - Support for software shadow call stacks - Various cleanups and fixes * tag 'riscv-for-linus-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (31 commits) RISC-V: hwprobe: Fix vDSO SIGSEGV riscv: configs: defconfig: Enable configs required for RZ/Five SoC riscv: errata: prefix T-Head mnemonics with th. riscv: put interrupt entries into .irqentry.text riscv: mm: Update the comment of CONFIG_PAGE_OFFSET riscv: Using TOOLCHAIN_HAS_ZIHINTPAUSE marco replace zihintpause riscv/mm: Fix the comment for swap pte format RISC-V: clarify the QEMU workaround in ISA parser riscv: correct pt_level name via pgtable_l5/4_enabled RISC-V: Provide pgtable_l5_enabled on rv32 clocksource: timer-riscv: Increase rating of clock_event_device for Sstc clocksource: timer-riscv: Don't enable/disable timer interrupt lkdtm: Fix CFI_BACKWARD on RISC-V riscv: Use separate IRQ shadow call stacks riscv: Implement Shadow Call Stack riscv: Move global pointer loading to a macro riscv: Deduplicate IRQ stack switching riscv: VMAP_STACK overflow detection thread-safe RISC-V: cacheflush: Initialize CBO variables on ACPI systems RISC-V: ACPI: RHCT: Add function to get CBO block sizes ...
2023-10-10docs: move riscv under archCosta Shulyupin
and fix all in-tree references. Architecture-specific documentation is being moved into Documentation/arch/ as a way of cleaning up the top-level documentation directory and making the docs hierarchy more closely match the source hierarchy. Signed-off-by: Costa Shulyupin <costa.shul@redhat.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20230930185354.3034118-1-costa.shul@redhat.com
2023-09-21RISC-V: hwprobe: Expose Zicboz extension and its block sizeAndrew Jones
Expose Zicboz through hwprobe and also provide a key to extract its respective block size. Opportunistically add a macro and apply it to current extensions in order to avoid duplicating code. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Evan Green <evan@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20230918131518.56803-11-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-19Merge patch series "RISC-V: Export Zba, Zbb to usermode via hwprobe"Palmer Dabbelt
Evan Green <evan@rivosinc.com> says: This change detects the presence of Zba, Zbb, and Zbs extensions and exports them per-hart to userspace via the hwprobe mechanism. Glibc can then use these in setting up hwcaps-based library search paths. There's a little bit of extra housekeeping here: the first change adds Zba and Zbs to the set of extensions the kernel recognizes, and the second change starts tracking ISA features per-hart (in addition to the ANDed mask of features across all harts which the kernel uses to make decisions). Now that we track the ISA information per-hart, we could even fix up /proc/cpuinfo to accurately report extension per-hart, though I've left that out of this series for now. * b4-shazam-merge: RISC-V: hwprobe: Expose Zba, Zbb, and Zbs RISC-V: Track ISA extensions per hart RISC-V: Add Zba, Zbs extension probing Link: https://lore.kernel.org/r/20230509182504.2997252-1-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-19RISC-V: hwprobe: Expose Zba, Zbb, and ZbsEvan Green
Add two new bits to the IMA_EXT_0 key for ZBA, ZBB, and ZBS extensions. These are accurately reported per CPU. Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Link: https://lore.kernel.org/r/20230509182504.2997252-4-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-06-08riscv: hwprobe: Add support for probing V in RISCV_HWPROBE_KEY_IMA_EXT_0Andy Chiu
Probing kernel support for Vector extension is available now. This only add detection for V only. Extenions like Zvfh, Zk are not in this scope. Signed-off-by: Andy Chiu <andy.chiu@sifive.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Evan Green <evan@rivosinc.com> Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com> Link: https://lore.kernel.org/r/20230605110724.21391-4-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18RISC-V: hwprobe: Support probing of misaligned access performanceEvan Green
This allows userspace to select various routines to use based on the performance of misaligned access on the target hardware. Rather than adding DT bindings, this change taps into the alternatives mechanism used to probe CPU errata. Add a new function pointer alongside the vendor-specific errata_patch_func() that probes for desirable errata (otherwise known as "features"). Unlike the errata_patch_func(), this function is called on each CPU as it comes up, so it can save feature information per-CPU. The T-head C906 has fast unaligned access, both as defined by GCC [1], and in performing a basic benchmark, which determined that byte copies are >50% slower than a misaligned word copy of the same data size (source for this test at [2]): bytecopy size f000 count 50000 offset 0 took 31664899 us wordcopy size f000 count 50000 offset 0 took 5180919 us wordcopy size f000 count 50000 offset 1 took 13416949 us [1] https://github.com/gcc-mirror/gcc/blob/master/gcc/config/riscv/riscv.cc#L353 [2] https://pastebin.com/EPXvDHSW Co-developed-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com> Link: https://lore.kernel.org/r/20230407231103.2622178-5-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18RISC-V: hwprobe: Add support for RISCV_HWPROBE_BASE_BEHAVIOR_IMAEvan Green
We have an implicit set of base behaviors that userspace depends on, which are mostly defined in various ISA specifications. Co-developed-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com> Link: https://lore.kernel.org/r/20230407231103.2622178-4-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-04-18RISC-V: Add a syscall for HW probingEvan Green
We don't have enough space for these all in ELF_HWCAP{,2} and there's no system call that quite does this, so let's just provide an arch-specific one to probe for hardware capabilities. This currently just provides m{arch,imp,vendor}id, but with the key-value pairs we can pass more in the future. Co-developed-by: Palmer Dabbelt <palmer@rivosinc.com> Signed-off-by: Evan Green <evan@rivosinc.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Tested-by: Heiko Stuebner <heiko.stuebner@vrull.eu> Reviewed-by: Paul Walmsley <paul.walmsley@sifive.com> Link: https://lore.kernel.org/r/20230407231103.2622178-3-evan@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>