summaryrefslogtreecommitdiffstats
path: root/arch/riscv/kernel/cpufeature.c
AgeCommit message (Collapse)AuthorFilesLines
2022-12-09RISC-V: Ensure Zicbom has a valid block sizeAndrew Jones1-0/+13
When a DT puts zicbom in the isa string, but does not provide a block size, ALT_CMO_OP() will attempt to do cache operations on address zero since the start address will be ANDed with zero. We can't simply BUG() in riscv_init_cbom_blocksize() when we fail to find a block size because the failure will happen before logging works, leaving users to scratch their heads as to why the boot hung. Instead, ensure Zicbom is disabled and output an error which will hopefully alert people that the DT needs to be fixed. While at it, add a check that the block size is a power-of-2 too. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Link: https://lore.kernel.org/r/20221129143447.49714-4-ajones@ventanamicro.com [Palmer: base on 5c20a3a9df19 ("RISC-V: Fix compilation without RISCV_ISA_ZICBOM"] Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-09RISC-V: Introduce riscv_isa_extension_checkAndrew Jones1-3/+11
Currently any isa extension found in the isa string is set in the isa bitmap. An isa extension set in the bitmap indicates that the extension is present and may be used (a.k.a is enabled). However, when an extension cannot be used due to missing dependencies or errata it should not be added to the bitmap. Introduce a function where additional checks may be placed in order to determine if an extension should be enabled or not. Note, the checks may simply indicate an issue with the DT, but, since extensions may be used in early boot, it's not always possible to simply produce an error at the point the issue is determined. It's best to keep the extension disabled and produce an error. No functional change intended, as the function is only introduced and always returns true. A later patch will provide checks for an isa extension. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Link: https://lore.kernel.org/r/20221129143447.49714-3-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-12-09RISC-V: Improve use of isa2hwcap[]Andrew Jones1-9/+11
Improve isa2hwcap[] by removing it from static storage, as riscv_fill_hwcap() is only called once, and by reducing its size from 256 bytes to 26. The latter improvement is possible because isa2hwcap[] will never be indexed with capital letters and we can precompute the offsets from 'a'. No functional change intended. Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Heiko Stuebner <heiko@sntech.de> Link: https://lore.kernel.org/r/20221129143447.49714-2-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-10-14Merge tag 'riscv-for-linus-6.1-mw2' of ↵Linus Torvalds1-23/+16
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull more RISC-V updates from Palmer Dabbelt: - DT updates for the PolarFire SOC - a fix to correct the handling of write-only mappings - m{vetndor,arcd,imp}id is now in /proc/cpuinfo - the SiFive L2 cache controller support has been refactored to also support L3 caches - misc fixes, cleanups and improvements throughout the tree * tag 'riscv-for-linus-6.1-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits) MAINTAINERS: add RISC-V's patchwork RISC-V: Make port I/O string accessors actually work riscv: enable software resend of irqs RISC-V: Re-enable counter access from userspace riscv: vdso: fix NULL deference in vdso_join_timens() when vfork riscv: Add cache information in AUX vector soc: sifive: ccache: define the macro for the register shifts soc: sifive: ccache: use pr_fmt() to remove CCACHE: prefixes soc: sifive: ccache: reduce printing on init soc: sifive: ccache: determine the cache level from dts soc: sifive: ccache: Rename SiFive L2 cache to Composable cache. dt-bindings: sifive-ccache: change Sifive L2 cache to Composable cache riscv: check for kernel config option in t-head memory types errata riscv: use BIT() marco for cpufeature probing riscv: use BIT() macros in t-head errata init riscv: drop some idefs from CMO initialization riscv: cleanup svpbmt cpufeature probing riscv: Pass -mno-relax only on lld < 15.0.0 RISC-V: Avoid dereferening NULL regs in die() dt-bindings: riscv: add new riscv,isa strings for emulators ...
2022-10-13Merge patch series "Some style cleanups for recent extension additions"Palmer Dabbelt1-23/+16
Heiko Stuebner <heiko@sntech.de> says: As noted by some people, some parts of the recently added extensions (svpbmt, zicbom) + t-head errata could use some styling upgrades. So this series provides these. changes in v2: - add patch also converting cpufeature probe to BIT() - update commit message in patch1 (Conor) Heiko Stuebner (5): riscv: cleanup svpbmt cpufeature probing riscv: drop some idefs from CMO initialization riscv: use BIT() macros in t-head errata init riscv: use BIT() marco for cpufeature probing riscv: check for kernel config option in t-head memory types errata arch/riscv/errata/thead/errata.c | 14 ++++++----- arch/riscv/include/asm/cacheflush.h | 2 ++ arch/riscv/kernel/cpufeature.c | 39 ++++++++++++----------------- 3 files changed, 26 insertions(+), 29 deletions(-) Link: https://lore.kernel.org/r/20220905111027.2463297-1-heiko@sntech.de * b4-shazam-merge: riscv: check for kernel config option in t-head memory types errata riscv: use BIT() marco for cpufeature probing riscv: use BIT() macros in t-head errata init riscv: drop some idefs from CMO initialization riscv: cleanup svpbmt cpufeature probing Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-10-13riscv: use BIT() marco for cpufeature probingHeiko Stuebner1-2/+2
Using the appropriate BIT macro makes the code better readable. Suggested-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20220905111027.2463297-5-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-10-13riscv: drop some idefs from CMO initializationHeiko Stuebner1-13/+9
Wrapping things in #ifdefs makes the code harder to read while we also have IS_ENABLED() macros to do this in regular code and the extension detection is not _that_ runtime critical. So define a stub for riscv_noncoherent_supported() in the non-CONFIG_RISCV_DMA_NONCOHERENT case and move the code to us IS_ENABLED. Suggested-by: Conor Dooley <conor.dooley@microchip.com> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20220905111027.2463297-3-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-10-13riscv: cleanup svpbmt cpufeature probingHeiko Stuebner1-8/+5
For better readability (and compile time coverage) use IS_ENABLED instead of ifdef and drop the new unneeded switch statement. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Guo Ren <guoren@kernel.org> Reviewed-by: Conor Dooley <conor.dooley@microchip.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Link: https://lore.kernel.org/r/20220905111027.2463297-2-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-10-02RISC-V: Probe Svinval extension form ISA stringMayuresh Chitale1-0/+1
Just like other ISA extensions, we allow callers/users to detect the presence of Svinval extension from ISA string. Signed-off-by: Mayuresh Chitale <mchitale@ventanamicro.com> Signed-off-by: Anup Patel <apatel@ventanamicro.com> Reviewed-by: Andrew Jones <ajones@ventanamicro.com> Signed-off-by: Anup Patel <anup@brainfault.org>
2022-08-16riscv: Ensure isa-ext static keys are writableAndrew Jones1-1/+1
riscv_isa_ext_keys[] is an array of static keys used in the unified ISA extension framework. The keys added to this array may be used anywhere, including in modules. Ensure the keys remain writable by placing them in the data section. The need to change riscv_isa_ext_keys[]'s section was found when the kvm module started failing to load. Commit 8eb060e10185 ("arch/riscv: add Zihintpause support") adds a static branch check for a newly added isa-ext key to cpu_relax(), which kvm uses. Fixes: c360cbec3511 ("riscv: introduce unified static key mechanism for ISA extensions") Signed-off-by: Andrew Jones <ajones@ventanamicro.com> Cc: stable@vger.kernel.org Reported-by: Ron Economos <re@w6rz.net> Reported-by: Anup Patel <apatel@ventanamicro.com> Reported-by: Conor Dooley <conor.dooley@microchip.com> Tested-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20220816163058.3004536-1-ajones@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-08-11RISC-V: Add Sstc extension supportPalmer Dabbelt1-0/+1
This series implements Sstc extension support which was ratified recently. Before the Sstc extension, an SBI call is necessary to generate timer interrupts as only M-mode have access to the timecompare registers. Thus, there is significant latency to generate timer interrupts at kernel. For virtualized enviornments, its even worse as the KVM handles the SBI call and uses a software timer to emulate the timecomapre register. Sstc extension solves both these problems by defining a stimecmp/vstimecmp at supervisor (host/guest) level. It allows kernel to program a timer and recieve interrupt without supervisor execution enviornment (M-mode/HS mode) intervention. * palmer/riscv-sstc: RISC-V: Prefer sstc extension if available RISC-V: Enable sstc extension parsing from DT RISC-V: Add SSTC extension CSR details
2022-08-11RISC-V: Enable sstc extension parsing from DTAtish Patra1-0/+1
The ISA extension framework now allows parsing any multi-letter ISA extension. Enable that for sstc extension. Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20220722165047.519994-3-atishp@rivosinc.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-08-11arch/riscv: add Zihintpause supportDao Lu1-0/+1
Implement support for the ZiHintPause extension. The PAUSE instruction is a HINT that indicates the current hart’s rate of instruction retirement should be temporarily reduced or paused. Reviewed-by: Heiko Stuebner <heiko@sntech.de> Tested-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Dao Lu <daolu@rivosinc.com> [Palmer: Some minor merge conflicts.] Link: https://lore.kernel.org/all/20220620201530.3929352-1-daolu@rivosinc.com/ Link: https://lore.kernel.org/all/20220811053356.17375-1-palmer@rivosinc.com/ Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-08-10riscv: implement Zicbom-based CMO instructions + the t-head variantPalmer Dabbelt1-0/+24
This series is based on the alternatives changes done in my svpbmt series and thus also depends on Atish's isa-extension parsing series. It implements using the cache-management instructions from the Zicbom- extension to handle cache flush, etc actions on platforms needing them. SoCs using cpu cores from T-Head like the Allwinne D1 implement a different set of cache instructions. But while they are different, instructions they provide the same functionality, so a variant can easly hook into the existing alternatives mechanism on those. [Palmer: Some minor fixups, including a RISCV_ISA_ZICBOM dependency on MMU that's probably not strictly necessary. The Zicbom support will trip up sparse for users that have new toolchains, I just sent a patch.] Link: https://lore.kernel.org/all/20220706231536.2041855-1-heiko@sntech.de/ Link: https://lore.kernel.org/linux-sparse/20220811033138.20676-1-palmer@rivosinc.com/T/#u * palmer/riscv-zicbom: riscv: implement cache-management errata for T-Head SoCs riscv: Add support for non-coherent devices using zicbom extension dt-bindings: riscv: document cbom-block-size of: also handle dma-noncoherent in of_dma_is_coherent()
2022-07-28riscv: Add support for non-coherent devices using zicbom extensionHeiko Stuebner1-0/+24
The Zicbom ISA-extension was ratified in november 2021 and introduces instructions for dcache invalidate, clean and flush operations. Implement cache management operations for non-coherent devices based on them. Of course not all cores will support this, so implement an alternative-based mechanism that replaces empty instructions with ones done around Zicbom instructions. As discussed in previous versions, assume the platform being coherent by default so that non-coherent devices need to get marked accordingly by firmware. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220706231536.2041855-4-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-07-19RISC-V: Support for 64bit hartid on RV64 platformsPalmer Dabbelt1-2/+4
The hartid can be a 64bit value on RV64 platforms. This series updates the code so that 64bit hartid can be supported on RV64 platforms. * 'riscv-64bit_hartid' of git://git.kernel.org/pub/scm/linux/kernel/git/palmer/linux.git: riscv/efi_stub: Add 64bit boot-hartid support on RV64 riscv: cpu: Add 64bit hartid support on RV64 riscv: smp: Add 64bit hartid support on RV64 riscv: spinwait: Fix hartid variable type riscv: cpu_ops_sbi: Add 64bit hartid support on RV64
2022-07-19riscv: cpu: Add 64bit hartid support on RV64Sunil V L1-2/+4
The hartid can be a 64bit value on RV64 platforms. Add support for 64bit hartid in riscv_of_processor_hartid() and update its callers. Signed-off-by: Sunil V L <sunilvl@ventanamicro.com> Reviewed-by: Atish Patra <atishp@rivosinc.com> Link: https://lore.kernel.org/r/20220527051743.2829940-5-sunilvl@ventanamicro.com Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-06-16RISC-V: Some Svpbmt fixes and cleanupsPalmer Dabbelt1-26/+11
Some additionals comments and notes from autobuilders received after the series got applied, warranted some changes. * 'riscv-svpbmt' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/palmer/linux: riscv: remove usage of function-pointers from cpufeatures and t-head errata riscv: make patch-function pointer more generic in cpu_manufacturer_info struct riscv: Improve description for RISCV_ISA_SVPBMT Kconfig symbol riscv: drop cpufeature_apply_feature tracking variable riscv: fix dependency for t-head errata
2022-06-16riscv: remove usage of function-pointers from cpufeatures and t-head errataHeiko Stuebner1-22/+10
Having a list of alternatives to check with a per-entry function pointer to a check function is nice style-wise. But in case of early-alternatives it can clash with the non-relocated kernel and the function pointer in the list pointing to a completely wrong location. This isn't an issue with one or two list entries, as in that case the compiler seems to unroll the loop and even usage of the list structure and then only does relative jumps into the check functions based on this. When adding a third entry to either list though, the issue that was hiding there from the beginning is triggered resulting a jump to a memory address that isn't part of the kernel at all. The list of features/erratas only contained an unused name and the pointer to the check function, so an easy solution for the problem is to just unroll the loop in code, dismantle the whole list structure and just call the relevant check functions one by one ourself. For the T-Head errata this includes moving the stage-check inside the check functions. The issue is only relevant for things that might be called for early- alternatives (T-Head and possible future main extensions), so the SiFive erratas were not affected from the beginning, as they got an early return for early-alternatives in the original patchset. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Tested-by: Samuel Holland <samuel@sholland.org> Link: https://lore.kernel.org/r/20220526205646.258337-6-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-06-16riscv: drop cpufeature_apply_feature tracking variableHeiko Stuebner1-4/+1
The variable was tracking which feature patches got applied but that information was never actually used - and thus resulted in a warning as well. Drop the variable. Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Guo Ren <guoren@kernel.org> Link: https://lore.kernel.org/r/20220526205646.258337-2-heiko@sntech.de Fixes: ff689fd21cb1 ("riscv: add RISC-V Svpbmt extension support") Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-06-16riscv: switch has_fpu() to the unified static key mechanismJisheng Zhang1-7/+0
This is to use the unified static key mechanism instead of putting static key related here and there. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20220522153543.2656-3-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-06-16riscv: introduce unified static key mechanism for ISA extensionsJisheng Zhang1-0/+7
Currently, riscv has several extensions which may not be supported on all riscv platforms, for example, FPU and so on. To support unified kernel Image style, we need to check whether the feature is supported or not. If the check sits at hot code path, then performance will be impacted a lot. static key can be used to solve the issue. In the past, FPU support has been converted to use static key mechanism. I believe we will have similar cases in the future. This patch tries to add an unified mechanism to use static keys for some ISA extensions by implementing an array of default-false static keys and enabling them when detected. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Reviewed-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Link: https://lore.kernel.org/r/20220522153543.2656-2-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-06-04Merge tag 'bitmap-for-5.19-rc1' of https://github.com/norov/linuxLinus Torvalds1-4/+3
Pull bitmap updates from Yury Norov: - bitmap: optimize bitmap_weight() usage, from me - lib/bitmap.c make bitmap_print_bitmask_to_buf parseable, from Mauro Carvalho Chehab - include/linux/find: Fix documentation, from Anna-Maria Behnsen - bitmap: fix conversion from/to fix-sized arrays, from me - bitmap: Fix return values to be unsigned, from Kees Cook It has been in linux-next for at least a week with no problems. * tag 'bitmap-for-5.19-rc1' of https://github.com/norov/linux: (31 commits) nodemask: Fix return values to be unsigned bitmap: Fix return values to be unsigned KVM: x86: hyper-v: replace bitmap_weight() with hweight64() KVM: x86: hyper-v: fix type of valid_bank_mask ia64: cleanup remove_siblinginfo() drm/amd/pm: use bitmap_{from,to}_arr32 where appropriate KVM: s390: replace bitmap_copy with bitmap_{from,to}_arr64 where appropriate lib/bitmap: add test for bitmap_{from,to}_arr64 lib: add bitmap_{from,to}_arr64 lib/bitmap: extend comment for bitmap_(from,to)_arr32() include/linux/find: Fix documentation lib/bitmap.c make bitmap_print_bitmask_to_buf parseable MAINTAINERS: add cpumask and nodemask files to BITMAP_API arch/x86: replace nodes_weight with nodes_empty where appropriate mm/vmstat: replace cpumask_weight with cpumask_empty where appropriate clocksource: replace cpumask_weight with cpumask_empty in clocksource.c genirq/affinity: replace cpumask_weight with cpumask_empty where appropriate irq: mips: replace cpumask_weight with cpumask_empty where appropriate drm/i915/pmu: replace cpumask_weight with cpumask_empty where appropriate arch/x86: replace cpumask_weight with cpumask_empty where appropriate ...
2022-06-03risc-v: replace bitmap_weight with bitmap_empty in riscv_fill_hwcap()Yury Norov1-4/+3
bitmap_empty() is better than bitmap_weight() because it may return earlier, and improves on readability. CC: Albert Ou <aou@eecs.berkeley.edu> CC: Anup Patel <anup@brainfault.org> CC: Atish Patra <atishp@atishpatra.org> CC: Jisheng Zhang <jszhang@kernel.org> CC: Palmer Dabbelt <palmer@dabbelt.com> CC: Paul Walmsley <paul.walmsley@sifive.com> CC: Tsukasa OI <research_trasio@irq.a4lg.com> CC: linux-riscv@lists.infradead.org CC: linux-kernel@vger.kernel.org Signed-off-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Anup Patel <anup@brainfault.org>
2022-05-11riscv: add memory-type errata for T-HeadHeiko Stuebner1-1/+6
Some current cpus based on T-Head cores implement memory-types way different than described in the svpbmt spec even going so far as using PTE bits marked as reserved. Add the T-Head vendor-id and necessary errata code to replace the affected instructions. Signed-off-by: Heiko Stuebner <heiko@sntech.de> Tested-by: Samuel Holland <samuel@sholland.org> Link: https://lore.kernel.org/r/20220511192921.2223629-13-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-05-11riscv: add RISC-V Svpbmt extension supportHeiko Stuebner1-1/+74
Svpbmt (the S should be capitalized) is the "Supervisor-mode: page-based memory types" extension that specifies attributes for cacheability, idempotency and ordering. The relevant settings are done in special bits in PTEs: Here is the svpbmt PTE format: | 63 | 62-61 | 60-8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 N MT RSW D A G U X W R V ^ Of the Reserved bits [63:54] in a leaf PTE, the high bit is already allocated (as the N bit), so bits [62:61] are used as the MT (aka MemType) field. This field specifies one of three memory types that are close equivalents (or equivalent in effect) to the three main x86 and ARMv8 memory types - as shown in the following table. RISC-V Encoding & MemType RISC-V Description ---------- ------------------------------------------------ 00 - PMA Normal Cacheable, No change to implied PMA memory type 01 - NC Non-cacheable, idempotent, weakly-ordered Main Memory 10 - IO Non-cacheable, non-idempotent, strongly-ordered I/O memory 11 - Rsvd Reserved for future standard use As the extension will not be present on all implementations, implement a method to handle cpufeatures via alternatives to not incur runtime penalties on cpu variants not supporting specific extensions and patch relevant code parts at runtime. Co-developed-by: Wei Fu <wefu@redhat.com> Signed-off-by: Wei Fu <wefu@redhat.com> Co-developed-by: Liu Shaohua <liush@allwinnertech.com> Signed-off-by: Liu Shaohua <liush@allwinnertech.com> Co-developed-by: Guo Ren <guoren@kernel.org> Signed-off-by: Guo Ren <guoren@kernel.org> [moved to use the alternatives mechanism] Signed-off-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Philipp Tomsich <philipp.tomsich@vrull.eu> Link: https://lore.kernel.org/r/20220511192921.2223629-10-heiko@sntech.de Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-21RISC-V: Add sscofpmf extension supportAtish Patra1-0/+2
The sscofpmf extension allows counter overflow and filtering for programmable counters. Enable the perf driver to handle the overflow interrupt. The overflow interrupt is a hart local interrupt. Thus, per cpu overflow interrupts are setup as a child under the root INTC irq domain. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-17RISC-V: Do no continue isa string parsing without correct XLENAtish Patra1-0/+5
The isa string should begin with either rv64 or rv32. Otherwise, it is an incorrect isa string. Currently, the string parsing continues even if it doesnot begin with current XLEN. Fix this by checking if it found "rv64" or "rv32" in the beginning. Tested-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-17RISC-V: Implement multi-letter ISA extension probing frameworkAtish Patra1-6/+16
Multi-letter extensions can be probed using exising riscv_isa_extension_available API now. It doesn't support versioning right now as there is no use case for it. Individual extension specific implementation will be added during each extension support. Tested-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Atish Patra <atishp@rivosinc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-17RISC-V: Extract multi-letter extension names from "riscv, isa"Tsukasa OI1-8/+27
Currently, there is no usage for version numbers in extensions as any ratified non base ISA extension will always at v1.0. Extract the extension names in place for future parsing. Tested-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Tsukasa OI <research_trasio@irq.a4lg.com> [Improved commit text and comments] Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-17RISC-V: Minimal parser for "riscv, isa" stringsTsukasa OI1-11/+61
Current hart ISA ("riscv,isa") parser don't correctly parse: 1. Multi-letter extensions 2. Version numbers All ISA extensions ratified recently has multi-letter extensions (except 'H'). The current "riscv,isa" parser that is easily confused by multi-letter extensions and "p" in version numbers can be a huge problem for adding new extensions through the device tree. Leaving it would create incompatible hacks and would make "riscv,isa" value unreliable. This commit implements minimal parser for "riscv,isa" strings. With this, we can safely ignore multi-letter extensions and version numbers. [Improved commit text and fixed a bug around 's' in base extension] Signed-off-by: Atish Patra <atishp@rivosinc.com> [Fixed workaround for QEMU] Signed-off-by: Tsukasa OI <research_trasio@irq.a4lg.com> Tested-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Anup Patel <anup@brainfault.org> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2022-03-17RISC-V: Correctly print supported extensionsTsukasa OI1-3/+5
This commit replaces BITS_PER_LONG with number of alphabet letters. Current ISA pretty-printing code expects extension 'a' (bit 0) through 'z' (bit 25). Although bit 26 and higher is not currently used (thus never cause an issue in practice), it will be an annoying problem if we start to use those in the future. This commit disables printing high bits for now. Reviewed-by: Anup Patel <anup@brainfault.org> Tested-by: Heiko Stuebner <heiko@sntech.de> Signed-off-by: Tsukasa OI <research_trasio@irq.a4lg.com> Signed-off-by: Atish Patra <atishp@rivosinc.com> Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2021-05-29riscv: Add __init section marker to some functions againJisheng Zhang1-1/+1
These functions are not needed after booting, so mark them as __init to move them to the __init section. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2021-05-25riscv: Turn has_fpu into a static key if FPU=yJisheng Zhang1-2/+2
The has_fpu check sits at hot code path: switch_to(). Currently, has_fpu is a bool variable if FPU=y, switch_to() checks it each time, we can optimize out this check by turning the has_fpu into a static key. Signed-off-by: Jisheng Zhang <jszhang@kernel.org> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2020-05-04RISC-V: Add bitmap reprensenting ISA features common across CPUsAnup Patel1-3/+80
This patch adds riscv_isa bitmap which represents Host ISA features common across all Host CPUs. The riscv_isa is not same as elf_hwcap because elf_hwcap will only have ISA features relevant for user-space apps whereas riscv_isa will have ISA features relevant to both kernel and user-space apps. One of the use-case for riscv_isa bitmap is in KVM hypervisor where we will use it to do following operations: 1. Check whether hypervisor extension is available 2. Find ISA features that need to be virtualized (e.g. floating point support, vector extension, etc.) Signed-off-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Alexander Graf <graf@amazon.com> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
2019-10-28riscv: add missing header file includesPaul Walmsley1-0/+1
sparse identifies several missing prototypes caused by missing preprocessor include directives: arch/riscv/kernel/cpufeature.c:16:6: warning: symbol 'has_fpu' was not declared. Should it be static? arch/riscv/kernel/process.c:26:6: warning: symbol 'arch_cpu_idle' was not declared. Should it be static? arch/riscv/kernel/reset.c:15:6: warning: symbol 'pm_power_off' was not declared. Should it be static? arch/riscv/kernel/syscall_table.c:15:6: warning: symbol 'sys_call_table' was not declared. Should it be static? arch/riscv/kernel/traps.c:149:13: warning: symbol 'trap_init' was not declared. Should it be static? arch/riscv/kernel/vdso.c:54:5: warning: symbol 'arch_setup_additional_pages' was not declared. Should it be static? arch/riscv/kernel/smp.c:64:6: warning: symbol 'arch_match_cpu_phys_id' was not declared. Should it be static? arch/riscv/kernel/module-sections.c:89:5: warning: symbol 'module_frob_arch_sections' was not declared. Should it be static? arch/riscv/mm/context.c:42:6: warning: symbol 'switch_mm' was not declared. Should it be static? Fix by including the appropriate header files in the appropriate source files. This patch should have no functional impact. Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234Thomas Gleixner1-12/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not see http www gnu org licenses extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-03-04RISC-V: Assign hwcap as per comman capabilities.Atish Patra1-19/+22
Currently, we set hwcap based on first valid hart from DT. This may not be correct always as that hart might not be current booting cpu or may have a different capability. Set hwcap as the capabilities supported by all possible harts with "okay" status. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Johan Hovold <johan@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11riscv: use for_each_of_cpu_node iteratorJohan Hovold1-2/+3
Use the new for_each_of_cpu_node() helper to iterate over cpu nodes instead of open coding. Note that this will allow matching also on the node name instead of the (for FDT) deprecated device_type property. Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2019-02-11riscv: add missing newlines to printk messagesJohan Hovold1-4/+4
Add missing newline characters to printk messages. Also replace two pr_warning with the shorter pr_warn, and fix up the tense of one error message while at it. Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-12-21RISC-V: Fix of_node_* refcountAtish Patra1-0/+2
Fix of_node* refcount at various places by using of_node_put. Signed-off-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-31RISC-V: properly determine hardware capsAndreas Schwab1-3/+5
On the Hifive-U platform, cpu 0 is a masked cpu with less capabilities than the other cpus. Ignore it for the purpose of determining the hardware capabilities of the system. Signed-off-by: Andreas Schwab <schwab@suse.de> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22riscv: Add support to no-FPU systemsPalmer Dabbelt1-0/+8
This patchset adds an option, CONFIG_FPU, to enable/disable floating- point support within the kernel. The kernel's new behavior will be as follows: * with CONFIG_FPU=y All FPU codes are reserved. If no FPU is found during booting, a global flag will be set, and those functions will be bypassed with condition check to that flag. * with CONFIG_FPU=n No floating-point instructions in kernel and all related settings are excluded. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22RISC-V: Mask out the F extension on systems without DPalmer Dabbelt1-0/+7
The RISC-V Linux port doesn't support systems that have the F extension but don't have the D extension -- we actually don't support systems without D either, but Alan's patch set is rectifying that soon. For now I think we can leave this in a semi-broken state and just wait for Alan's patch set to get merged for proper non-FPU support -- the patch set is starting to look good, so doing something in-between doesn't seem like it's worth the work. I don't think it's worth fretting about support for systems with F but not D for now: our glibc ABIs are IMAC and IMAFDC so they probably won't end up being popular. We can always extend this in the future. CC: Alan Kao <alankao@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2018-10-22Auto-detect whether a FPU existsAlan Kao1-0/+8
We expect that a kernel with CONFIG_FPU=y can still support no-FPU machines. To do so, the kernel should first examine the existence of a FPU, then do nothing if a FPU does exist; otherwise, it should disable/bypass all FPU-related functions. In this patch, a new global variable, has_fpu, is created and determined when parsing the hardware capability from device tree during booting. This variable is used in those FPU-related functions. Signed-off-by: Alan Kao <alankao@andestech.com> Cc: Greentime Hu <greentime@andestech.com> Cc: Vincent Chen <vincentc@andestech.com> Cc: Zong Li <zong@andestech.com> Cc: Nick Hu <nickhu@andestech.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2017-09-26RISC-V: User-facing APIPalmer Dabbelt1-0/+61
This patch contains code that is in some way visible to the user: including via system calls, the VDSO, module loading and signal handling. It also contains some generic code that is ABI visible. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>