summaryrefslogtreecommitdiff
path: root/arch/arm64/kernel/fpsimd.c
AgeCommit message (Collapse)Author
2021-12-14arm64/fp: Add comments documenting the usage of state restore functionsMark Brown
Add comments to help people figure out when fpsimd_bind_state_to_cpu() and fpsimd_update_current_state() are used. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211207163250.1373542-1-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-12-14arm64/sve: Generalise vector length configuration prctl() for SMEMark Brown
In preparation for adding SME support update the bulk of the implementation for the vector length configuration prctl() calls to be independent of vector type. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211210184133.320748-3-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-12-14arm64/sve: Make sysctl interface for SVE reusable by SMEMark Brown
The vector length configuration for SME is very similar to that for SVE so in order to allow reuse refactor the SVE configuration so that it takes the vector type from the struct ctl_table. Since there's no dedicated space for this we repurpose the extra1 field to store the vector type, this is otherwise unused for integer sysctls. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211210184133.320748-2-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-11-22arm64/fpsimd: Document the use of TIF_FOREIGN_FPSTATE by KVMMarc Zyngier
The bit of documentation that talks about TIF_FOREIGN_FPSTATE does not mention the ungodly tricks that KVM plays with this flag. Try and document this for the posterity. Reviewed-by: Mark Brown <broonie@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-10-26arm64/sve: Fix warnings when SVE is disabledMark Brown
In configurations where SVE is disabled we define but never reference the functions for retrieving the default vector length, causing warnings. Fix this by move the ifdef up, marking get_default_vl() inline since it is referenced from code guarded by an IS_ENABLED() check, and do the same for the other accessors for consistency. Reported-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211022141635.2360415-3-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21arm64/sve: Track vector lengths for tasks in an arrayMark Brown
As for SVE we will track a per task SME vector length for tasks. Convert the existing storage for the vector length into an array and update fpsimd_flush_task() to initialise this in a function. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211019172247.3045838-10-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21arm64/sve: Explicitly load vector length when restoring SVE stateMark Brown
Currently when restoring the SVE state we supply the SVE vector length as an argument to sve_load_state() and the underlying macros. This becomes inconvenient with the addition of SME since we may need to restore any combination of SVE and SME vector lengths, and we already separately restore the vector length in the KVM code. We don't need to know the vector length during the actual register load since the SME load instructions can index into the data array for us. Refactor the interface so we explicitly set the vector length separately to restoring the SVE registers in preparation for adding SME support, no functional change should be involved. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211019172247.3045838-9-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21arm64/sve: Put system wide vector length information into structsMark Brown
With the introduction of SME we will have a second vector length in the system, enumerated and configured in a very similar fashion to the existing SVE vector length. While there are a few differences in how things are handled this is a relatively small portion of the overall code so in order to avoid code duplication we factor out We create two structs, one vl_info for the static hardware properties and one vl_config for the runtime configuration, with an array instantiated for each and update all the users to reference these. Some accessor functions are provided where helpful for readability, and the write to set the vector length is put into a function since the system register being updated needs to be chosen at compile time. This is a mostly mechanical replacement, further work will be required to actually make things generic, ensuring that we handle those places where there are differences properly. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211019172247.3045838-8-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21arm64/sve: Use accessor functions for vector lengths in thread_structMark Brown
In a system with SME there are parallel vector length controls for SVE and SME vectors which function in much the same way so it is desirable to share the code for handling them as much as possible. In order to prepare for doing this add a layer of accessor functions for the various VL related operations on tasks. Since almost all current interactions are actually via task->thread rather than directly with the thread_info the accessors use that. Accessors are provided for both generic and SVE specific usage, the generic accessors should be used for cases where register state is being manipulated since the registers are shared between streaming and regular SVE so we know that when SME support is implemented we will always have to be in the appropriate mode already and hence can generalise now. Since we are using task_struct and we don't want to cause widespread inclusion of sched.h the acessors are all out of line, it is hoped that none of the uses are in a sufficiently critical path for this to be an issue. Those that are most likely to present an issue are in the same translation unit so hopefully the compiler may be able to inline anyway. This is purely adding the layer of abstraction, additional work will be needed to support tasks using SME. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211019172247.3045838-7-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21arm64/sve: Rename find_supported_vector_length()Mark Brown
The function has SVE specific checks in it and it will be more trouble to add conditional code for SME than it is to simply rename it to be SVE specific. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211019172247.3045838-6-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21arm64/sve: Make access to FFR optionalMark Brown
SME introduces streaming SVE mode in which FFR is not present and the instructions for accessing it UNDEF. In preparation for handling this update the low level SVE state access functions to take a flag specifying if FFR should be handled. When saving the register state we store a zero for FFR to guard against uninitialized data being read. No behaviour change should be introduced by this patch. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211019172247.3045838-5-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21arm64/sve: Make sve_state_size() staticMark Brown
There are no users outside fpsimd.c so make sve_state_size() static. KVM open codes an equivalent. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211019172247.3045838-4-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-10-21arm64/fp: Reindent fpsimd_save()Mark Brown
Currently all the active code in fpsimd_save() is inside a check for TIF_FOREIGN_FPSTATE. Reduce the indentation level by changing to return from the function if TIF_FOREIGN_FPSTATE is set. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20211019172247.3045838-2-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-09-16arm64/sve: Use correct size when reinitialising SVE stateMark Brown
When we need a buffer for SVE register state we call sve_alloc() to make sure that one is there. In order to avoid repeated allocations and frees we keep the buffer around unless we change vector length and just memset() it to ensure a clean register state. The function that deals with this takes the task to operate on as an argument, however in the case where we do a memset() we initialise using the SVE state size for the current task rather than the task passed as an argument. This is only an issue in the case where we are setting the register state for a task via ptrace and the task being configured has a different vector length to the task tracing it. In the case where the buffer is larger in the traced process we will leak old state from the traced process to itself, in the case where the buffer is smaller in the traced process we will overflow the buffer and corrupt memory. Fixes: bc0ee4760364 ("arm64/sve: Core task context handling") Cc: <stable@vger.kernel.org> # 4.15.x Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210909165356.10675-1-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-24arm64/sve: Better handle failure to allocate SVE register storageMark Brown
Currently we "handle" failure to allocate the SVE register storage by doing a BUG_ON() and hoping for the best. This is obviously not great and the memory allocation failure will already be loud enough without the BUG_ON(). As the comment says it is a corner case but let's try to do a bit better, remove the BUG_ON() and add code to handle the failure in the callers. For the ptrace and signal code we can return -ENOMEM gracefully however we have no real error reporting path available to us for the SVE access trap so instead generate a SIGKILL if the allocation fails there. This at least means that we won't try to soldier on and end up trying to access the nonexistant state and while it's obviously not ideal for userspace SIGKILL doesn't allow any handling so minimises the ABI impact, making it easier to improve the interface later if we come up with a better idea. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210824153417.18371-1-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-08-02arm64/sve: Make fpsimd_bind_task_to_cpu() staticMark Brown
This function is not referenced outside fpsimd.c so can be static, making it that little bit easier to follow what is called from where. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210730165846.18558-1-broonie@kernel.org Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-05-26arm64/sve: Skip flushing Z registers with 128 bit vectorsMark Brown
When the SVE vector length is 128 bits then there are no bits in the Z registers which are not shared with the V registers so we can skip them when zeroing state not shared with FPSIMD, this results in a minor performance improvement. Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Link: https://lore.kernel.org/r/20210512151131.27877-4-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2021-04-15Merge branches 'for-next/misc', 'for-next/kselftest', 'for-next/xntable', ↵Catalin Marinas
'for-next/vdso', 'for-next/fiq', 'for-next/epan', 'for-next/kasan-vmalloc', 'for-next/fgt-boot-init', 'for-next/vhe-only' and 'for-next/neon-softirqs-disabled', remote-tracking branch 'arm64/for-next/perf' into for-next/core * for-next/misc: : Miscellaneous patches arm64/sve: Add compile time checks for SVE hooks in generic functions arm64/kernel/probes: Use BUG_ON instead of if condition followed by BUG. arm64/sve: Remove redundant system_supports_sve() tests arm64: mte: Remove unused mte_assign_mem_tag_range() arm64: Add __init section marker to some functions arm64/sve: Rework SVE access trap to convert state in registers docs: arm64: Fix a grammar error arm64: smp: Add missing prototype for some smp.c functions arm64: setup: name `tcr` register arm64: setup: name `mair` register arm64: stacktrace: Move start_backtrace() out of the header arm64: barrier: Remove spec_bar() macro arm64: entry: remove test_irqs_unmasked macro ARM64: enable GENERIC_FIND_FIRST_BIT arm64: defconfig: Use DEBUG_INFO_REDUCED * for-next/kselftest: : Various kselftests for arm64 kselftest: arm64: Add BTI tests kselftest/arm64: mte: Report filename on failing temp file creation kselftest/arm64: mte: Fix clang warning kselftest/arm64: mte: Makefile: Fix clang compilation kselftest/arm64: mte: Output warning about failing compiler kselftest/arm64: mte: Use cross-compiler if specified kselftest/arm64: mte: Fix MTE feature detection kselftest/arm64: mte: common: Fix write() warnings kselftest/arm64: mte: user_mem: Fix write() warning kselftest/arm64: mte: ksm_options: Fix fscanf warning kselftest/arm64: mte: Fix pthread linking kselftest/arm64: mte: Fix compilation with native compiler * for-next/xntable: : Add hierarchical XN permissions for all page tables arm64: mm: use XN table mapping attributes for user/kernel mappings arm64: mm: use XN table mapping attributes for the linear region arm64: mm: add missing P4D definitions and use them consistently * for-next/vdso: : Minor improvements to the compat vdso and sigpage arm64: compat: Poison the compat sigpage arm64: vdso: Avoid ISB after reading from cntvct_el0 arm64: compat: Allow signal page to be remapped arm64: vdso: Remove redundant calls to flush_dcache_page() arm64: vdso: Use GFP_KERNEL for allocating compat vdso and signal pages * for-next/fiq: : Support arm64 FIQ controller registration arm64: irq: allow FIQs to be handled arm64: Always keep DAIF.[IF] in sync arm64: entry: factor irq triage logic into macros arm64: irq: rework root IRQ handler registration arm64: don't use GENERIC_IRQ_MULTI_HANDLER genirq: Allow architectures to override set_handle_irq() fallback * for-next/epan: : Support for Enhanced PAN (execute-only permissions) arm64: Support execute-only permissions with Enhanced PAN * for-next/kasan-vmalloc: : Support CONFIG_KASAN_VMALLOC on arm64 arm64: Kconfig: select KASAN_VMALLOC if KANSAN_GENERIC is enabled arm64: kaslr: support randomized module area with KASAN_VMALLOC arm64: Kconfig: support CONFIG_KASAN_VMALLOC arm64: kasan: abstract _text and _end to KERNEL_START/END arm64: kasan: don't populate vmalloc area for CONFIG_KASAN_VMALLOC * for-next/fgt-boot-init: : Booting clarifications and fine grained traps setup arm64: Require that system registers at all visible ELs be initialized arm64: Disable fine grained traps on boot arm64: Document requirements for fine grained traps at boot * for-next/vhe-only: : Dealing with VHE-only CPUs (a.k.a. M1) arm64: Get rid of CONFIG_ARM64_VHE arm64: Cope with CPUs stuck in VHE mode arm64: cpufeature: Allow early filtering of feature override * arm64/for-next/perf: arm64: perf: Remove redundant initialization in perf_event.c perf/arm_pmu_platform: Clean up with dev_printk perf/arm_pmu_platform: Fix error handling perf/arm_pmu_platform: Use dev_err_probe() for IRQ errors docs: perf: Address some html build warnings docs: perf: Add new description on HiSilicon uncore PMU v2 drivers/perf: hisi: Add support for HiSilicon PA PMU driver drivers/perf: hisi: Add support for HiSilicon SLLC PMU driver drivers/perf: hisi: Update DDRC PMU for programmable counter drivers/perf: hisi: Add new functions for HHA PMU drivers/perf: hisi: Add new functions for L3C PMU drivers/perf: hisi: Add PMU version for uncore PMU drivers. drivers/perf: hisi: Refactor code for more uncore PMUs drivers/perf: hisi: Remove unnecessary check of counter index drivers/perf: Simplify the SMMUv3 PMU event attributes drivers/perf: convert sysfs sprintf family to sysfs_emit drivers/perf: convert sysfs scnprintf family to sysfs_emit_at() and sysfs_emit() drivers/perf: convert sysfs snprintf family to sysfs_emit * for-next/neon-softirqs-disabled: : Run kernel mode SIMD with softirqs disabled arm64: fpsimd: run kernel mode NEON with softirqs disabled arm64: assembler: introduce wxN aliases for wN registers arm64: assembler: remove conditional NEON yield macros
2021-04-15arm64/sve: Add compile time checks for SVE hooks in generic functionsMark Brown
The FPSIMD code was relying on IS_ENABLED() checks in system_suppors_sve() to cause the compiler to delete references to SVE functions in some places, add explicit IS_ENABLED() checks back. Fixes: ef9c5d09797d ("arm64/sve: Remove redundant system_supports_sve() tests") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210415121742.36628-1-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-13arm64/sve: Remove redundant system_supports_sve() testsMark Brown
Currently there are a number of places in the SVE code where we check both system_supports_sve() and TIF_SVE. This is a bit redundant given that we should never get into a situation where we have set TIF_SVE without having SVE support and it is not clear that silently ignoring a mistakenly set TIF_SVE flag is the most sensible error handling approach. For now let's just drop the system_supports_sve() checks since this will at least reduce overhead a little. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210412172320.3315-1-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-12arm64: fpsimd: run kernel mode NEON with softirqs disabledArd Biesheuvel
Kernel mode NEON can be used in task or softirq context, but only in a non-nesting manner, i.e., softirq context is only permitted if the interrupt was not taken at a point where the kernel was using the NEON in task context. This means all users of kernel mode NEON have to be aware of this limitation, and either need to provide scalar fallbacks that may be much slower (up to 20x for AES instructions) and potentially less safe, or use an asynchronous interface that defers processing to a later time when the NEON is guaranteed to be available. Given that grabbing and releasing the NEON is cheap, we can relax this restriction, by increasing the granularity of kernel mode NEON code, and always disabling softirq processing while the NEON is being used in task context. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210302090118.30666-4-ardb@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-04-08arm64/sve: Rework SVE access trap to convert state in registersMark Brown
When we enable SVE usage in userspace after taking a SVE access trap we need to ensure that the portions of the register state that are not shared with the FPSIMD registers are zeroed. Currently we do this by forcing the FPSIMD registers to be saved to the task struct and converting them there. This is wasteful in the common case where the task state is loaded into the registers and we will immediately return to userspace since we can initialise the SVE state directly in registers instead of accessing multiple copies of the register state in memory. Instead in that common case do the conversion in the registers and update the task metadata so that we can return to userspace without spilling the register state to memory unless there is some other reason to do so. Signed-off-by: Mark Brown <broonie@kernel.org> Link: https://lore.kernel.org/r/20210312190313.24598-1-broonie@kernel.org Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-10-15arm64: reject prctl(PR_PAC_RESET_KEYS) on compat tasksPeter Collingbourne
It doesn't make sense to issue prctl(PR_PAC_RESET_KEYS) on a compat task because the 32-bit instruction set does not offer PAuth instructions. For consistency with other 64-bit only prctls such as {SET,GET}_TAGGED_ADDR_CTRL, reject the prctl on compat tasks. Although this is a userspace-visible change, maybe it isn't too late to make this change given that the hardware isn't available yet and it's very unlikely that anyone has 32-bit software that actually depends on this succeeding. Signed-off-by: Peter Collingbourne <pcc@google.com> Link: https://linux-review.googlesource.com/id/Ie885a1ff84ab498cc9f62d6451e9f2cfd4b1d06a Link: https://lore.kernel.org/r/20201014052430.11630-1-pcc@google.com [will: Do the same for the SVE prctl()s] Signed-off-by: Will Deacon <will@kernel.org>
2020-10-02Merge branches 'for-next/acpi', 'for-next/boot', 'for-next/bpf', ↵Will Deacon
'for-next/cpuinfo', 'for-next/fpsimd', 'for-next/misc', 'for-next/mm', 'for-next/pci', 'for-next/perf', 'for-next/ptrauth', 'for-next/sdei', 'for-next/selftests', 'for-next/stacktrace', 'for-next/svm', 'for-next/topology', 'for-next/tpyos' and 'for-next/vdso' into for-next/core Remove unused functions and parameters from ACPI IORT code. (Zenghui Yu via Lorenzo Pieralisi) * for-next/acpi: ACPI/IORT: Remove the unused inline functions ACPI/IORT: Drop the unused @ops of iort_add_device_replay() Remove redundant code and fix documentation of caching behaviour for the HVC_SOFT_RESTART hypercall. (Pingfan Liu) * for-next/boot: Documentation/kvm/arm: improve description of HVC_SOFT_RESTART arm64/relocate_kernel: remove redundant code Improve reporting of unexpected kernel traps due to BPF JIT failure. (Will Deacon) * for-next/bpf: arm64: Improve diagnostics when trapping BRK with FAULT_BRK_IMM Improve robustness of user-visible HWCAP strings and their corresponding numerical constants. (Anshuman Khandual) * for-next/cpuinfo: arm64/cpuinfo: Define HWCAP name arrays per their actual bit definitions Cleanups to handling of SVE and FPSIMD register state in preparation for potential future optimisation of handling across syscalls. (Julien Grall) * for-next/fpsimd: arm64/sve: Implement a helper to load SVE registers from FPSIMD state arm64/sve: Implement a helper to flush SVE registers arm64/fpsimdmacros: Allow the macro "for" to be used in more cases arm64/fpsimdmacros: Introduce a macro to update ZCR_EL1.LEN arm64/signal: Update the comment in preserve_sve_context arm64/fpsimd: Update documentation of do_sve_acc Miscellaneous changes. (Tian Tao and others) * for-next/misc: arm64/mm: return cpu_all_mask when node is NUMA_NO_NODE arm64: mm: Fix missing-prototypes in pageattr.c arm64/fpsimd: Fix missing-prototypes in fpsimd.c arm64: hibernate: Remove unused including <linux/version.h> arm64/mm: Refactor {pgd, pud, pmd, pte}_ERROR() arm64: Remove the unused include statements arm64: get rid of TEXT_OFFSET arm64: traps: Add str of description to panic() in die() Memory management updates and cleanups. (Anshuman Khandual and others) * for-next/mm: arm64: dbm: Invalidate local TLB when setting TCR_EL1.HD arm64: mm: Make flush_tlb_fix_spurious_fault() a no-op arm64/mm: Unify CONT_PMD_SHIFT arm64/mm: Unify CONT_PTE_SHIFT arm64/mm: Remove CONT_RANGE_OFFSET arm64/mm: Enable THP migration arm64/mm: Change THP helpers to comply with generic MM semantics arm64/mm/ptdump: Add address markers for BPF regions Allow prefetchable PCI BARs to be exposed to userspace using normal non-cacheable mappings. (Clint Sbisa) * for-next/pci: arm64: Enable PCI write-combine resources under sysfs Perf/PMU driver updates. (Julien Thierry and others) * for-next/perf: perf: arm-cmn: Fix conversion specifiers for node type perf: arm-cmn: Fix unsigned comparison to less than zero arm_pmu: arm64: Use NMIs for PMU arm_pmu: Introduce pmu_irq_ops KVM: arm64: pmu: Make overflow handler NMI safe arm64: perf: Defer irq_work to IPI_IRQ_WORK arm64: perf: Remove PMU locking arm64: perf: Avoid PMXEV* indirection arm64: perf: Add missing ISB in armv8pmu_enable_counter() perf: Add Arm CMN-600 PMU driver perf: Add Arm CMN-600 DT binding arm64: perf: Add support caps under sysfs drivers/perf: thunderx2_pmu: Fix memory resource error handling drivers/perf: xgene_pmu: Fix uninitialized resource struct perf: arm_dsu: Support DSU ACPI devices arm64: perf: Remove unnecessary event_idx check drivers/perf: hisi: Add missing include of linux/module.h arm64: perf: Add general hardware LLC events for PMUv3 Support for the Armv8.3 Pointer Authentication enhancements. (By Amit Daniel Kachhap) * for-next/ptrauth: arm64: kprobe: clarify the comment of steppable hint instructions arm64: kprobe: disable probe of fault prone ptrauth instruction arm64: cpufeature: Modify address authentication cpufeature to exact arm64: ptrauth: Introduce Armv8.3 pointer authentication enhancements arm64: traps: Allow force_signal_inject to pass esr error code arm64: kprobe: add checks for ARMv8.3-PAuth combined instructions Tonnes of cleanup to the SDEI driver. (Gavin Shan) * for-next/sdei: firmware: arm_sdei: Remove _sdei_event_unregister() firmware: arm_sdei: Remove _sdei_event_register() firmware: arm_sdei: Introduce sdei_do_local_call() firmware: arm_sdei: Cleanup on cross call function firmware: arm_sdei: Remove while loop in sdei_event_unregister() firmware: arm_sdei: Remove while loop in sdei_event_register() firmware: arm_sdei: Remove redundant error message in sdei_probe() firmware: arm_sdei: Remove duplicate check in sdei_get_conduit() firmware: arm_sdei: Unregister driver on error in sdei_init() firmware: arm_sdei: Avoid nested statements in sdei_init() firmware: arm_sdei: Retrieve event number from event instance firmware: arm_sdei: Common block for failing path in sdei_event_create() firmware: arm_sdei: Remove sdei_is_err() Selftests for Pointer Authentication and FPSIMD/SVE context-switching. (Mark Brown and Boyan Karatotev) * for-next/selftests: selftests: arm64: Add build and documentation for FP tests selftests: arm64: Add wrapper scripts for stress tests selftests: arm64: Add utility to set SVE vector lengths selftests: arm64: Add stress tests for FPSMID and SVE context switching selftests: arm64: Add test for the SVE ptrace interface selftests: arm64: Test case for enumeration of SVE vector lengths kselftests/arm64: add PAuth tests for single threaded consistency and differently initialized keys kselftests/arm64: add PAuth test for whether exec() changes keys kselftests/arm64: add nop checks for PAuth tests kselftests/arm64: add a basic Pointer Authentication test Implementation of ARCH_STACKWALK for unwinding. (Mark Brown) * for-next/stacktrace: arm64: Move console stack display code to stacktrace.c arm64: stacktrace: Convert to ARCH_STACKWALK arm64: stacktrace: Make stack walk callback consistent with generic code stacktrace: Remove reliable argument from arch_stack_walk() callback Support for ASID pinning, which is required when sharing page-tables with the SMMU. (Jean-Philippe Brucker) * for-next/svm: arm64: cpufeature: Export symbol read_sanitised_ftr_reg() arm64: mm: Pin down ASIDs for sharing mm with devices Rely on firmware tables for establishing CPU topology. (Valentin Schneider) * for-next/topology: arm64: topology: Stop using MPIDR for topology information Spelling fixes. (Xiaoming Ni and Yanfei Xu) * for-next/tpyos: arm64/numa: Fix a typo in comment of arm64_numa_init arm64: fix some spelling mistakes in the comments by codespell vDSO cleanups. (Will Deacon) * for-next/vdso: arm64: vdso: Fix unusual formatting in *setup_additional_pages() arm64: vdso32: Remove a bunch of #ifdef CONFIG_COMPAT_VDSO guards
2020-09-21arm64/fpsimd: Update documentation of do_sve_accJulien Grall
fpsimd_restore_current_state() enables and disables the SVE access trap based on TIF_SVE, not task_fpsimd_load(). Update the documentation of do_sve_acc to reflect this behavior. Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/20200828181155.17745-2-broonie@kernel.org Signed-off-by: Will Deacon <will@kernel.org>
2020-09-18arm64/fpsimd: Fix missing-prototypes in fpsimd.cTian Tao
Fix the following warnings. arch/arm64/kernel/fpsimd.c:935:6: warning: no previous prototype for ‘do_sve_acc’ [-Wmissing-prototypes] arch/arm64/kernel/fpsimd.c:962:6: warning: no previous prototype for ‘do_fpsimd_acc’ [-Wmissing-prototypes] arch/arm64/kernel/fpsimd.c:971:6: warning: no previous prototype for ‘do_fpsimd_exc’ [-Wmissing-prototypes] arch/arm64/kernel/fpsimd.c:1266:6: warning: no previous prototype for ‘kernel_neon_begin’ [-Wmissing-prototypes] arch/arm64/kernel/fpsimd.c:1292:6: warning: no previous prototype for ‘kernel_neon_end’ [-Wmissing-prototypes] Signed-off-by: Tian Tao <tiantao6@hisilicon.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/1600157999-14802-1-git-send-email-tiantao6@hisilicon.com Signed-off-by: Will Deacon <will@kernel.org>
2020-09-14arm64: traps: Allow force_signal_inject to pass esr error codeAmit Daniel Kachhap
Some error signal need to pass proper ARM esr error code to userspace to better identify the cause of the signal. So the function force_signal_inject is extended to pass this as a parameter. The existing code is not affected by this change. Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/20200914083656.21428-3-amit.kachhap@arm.com Signed-off-by: Will Deacon <will@kernel.org>
2020-06-16arm64: sve: Fix build failure when ARM64_SVE=y and SYSCTL=nWill Deacon
When I squashed the 'allnoconfig' compiler warning about the set_sve_default_vl() function being defined but not used in commit 1e570f512cbd ("arm64/sve: Eliminate data races on sve_default_vl"), I accidentally broke the build for configs where ARM64_SVE is enabled, but SYSCTL is not. Fix this by only compiling the SVE sysctl support if both CONFIG_SVE=y and CONFIG_SYSCTL=y. Cc: Dave Martin <Dave.Martin@arm.com> Reported-by: Qian Cai <cai@lca.pw> Link: https://lore.kernel.org/r/20200616131808.GA1040@lca.pw Signed-off-by: Will Deacon <will@kernel.org>
2020-06-15arm64/sve: Eliminate data races on sve_default_vlDave Martin
sve_default_vl can be modified via the /proc/sys/abi/sve_default_vl sysctl concurrently with use, and modified concurrently by multiple threads. Adding a lock for this seems overkill, and I don't want to think any more than necessary, so just define wrappers using READ_ONCE()/ WRITE_ONCE(). This will avoid the possibility of torn accesses and repeated loads and stores. There's no evidence yet that this is going wrong in practice: this is just hygiene. For generic sysctl users, it would be better to build this kind of thing into the sysctl common code somehow. Reported-by: Will Deacon <will@kernel.org> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Link: https://lore.kernel.org/r/1591808590-20210-3-git-send-email-Dave.Martin@arm.com [will: move set_sve_default_vl() inside #ifdef to squash allnoconfig warning] Signed-off-by: Will Deacon <will@kernel.org>
2020-04-27sysctl: pass kernel pointers to ->proc_handlerChristoph Hellwig
Instead of having all the sysctl handlers deal with user pointers, which is rather hairy in terms of the BPF interaction, copy the input to and from userspace in common code. This also means that the strings are always NUL-terminated by the common code, making the API a little bit safer. As most handler just pass through the data to one of the common handlers a lot of the changes are mechnical. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-01-14arm64: nofpsmid: Handle TIF_FOREIGN_FPSTATE flag cleanlySuzuki K Poulose
We detect the absence of FP/SIMD after an incapable CPU is brought up, and by then we have kernel threads running already with TIF_FOREIGN_FPSTATE set which could be set for early userspace applications (e.g, modprobe triggered from initramfs) and init. This could cause the applications to loop forever in do_nofity_resume() as we never clear the TIF flag, once we now know that we don't support FP. Fix this by making sure that we clear the TIF_FOREIGN_FPSTATE flag for tasks which may have them set, as we would have done in the normal case, but avoiding touching the hardware state (since we don't support any). Also to make sure we handle the cases seemlessly we categorise the helper functions to two : 1) Helpers for common core code, which calls into take appropriate actions without knowing the current FPSIMD state of the CPU/task. e.g fpsimd_restore_current_state(), fpsimd_flush_task_state(), fpsimd_save_and_flush_cpu_state(). We bail out early for these functions, taking any appropriate actions (e.g, clearing the TIF flag) where necessary to hide the handling from core code. 2) Helpers used when the presence of FP/SIMD is apparent. i.e, save/restore the FP/SIMD register state, modify the CPU/task FP/SIMD state. e.g, fpsimd_save(), task_fpsimd_load() - save/restore task FP/SIMD registers fpsimd_bind_task_to_cpu() \ - Update the "state" metadata for CPU/task. fpsimd_bind_state_to_cpu() / fpsimd_update_current_state() - Update the fp/simd state for the current task from memory. These must not be called in the absence of FP/SIMD. Put in a WARNING to make sure they are not invoked in the absence of FP/SIMD. KVM also uses the TIF_FOREIGN_FPSTATE flag to manage the FP/SIMD state on the CPU. However, without FP/SIMD support we trap all accesses and inject undefined instruction. Thus we should never "load" guest state. Add a sanity check to make sure this is valid. Fixes: 82e0191a1aa11abf ("arm64: Support systems without FP/ASIMD") Cc: Will Deacon <will@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ardb@kernel.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-10-28arm64: Remove asmlinkage from updated functionsJames Morse
Now that the callers of these functions have moved into C, they no longer need the asmlinkage annotation. Remove it. Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-07-22arm64/sve: Fix a couple of magic numbers for the Z-reg countDave Martin
There are some hand-written instances of "32" to express the number of SVE Z-registers. Since this code was written a #define was added for this, so convert trivial instances of this magic number as appropriate. No functional change. Reviewed-by: Julien Grall <julien.grall@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-07-22arm64/sve: Factor out FPSIMD to SVE state conversionDave Martin
Currently we convert from FPSIMD to SVE register state in memory in two places. To ease future maintenance, let's consolidate this in one place. Reviewed-by: Julien Grall <julien.grall@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will@kernel.org>
2019-07-08Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - arm64 support for syscall emulation via PTRACE_SYSEMU{,_SINGLESTEP} - Wire up VM_FLUSH_RESET_PERMS for arm64, allowing the core code to manage the permissions of executable vmalloc regions more strictly - Slight performance improvement by keeping softirqs enabled while touching the FPSIMD/SVE state (kernel_neon_begin/end) - Expose a couple of ARMv8.5 features to user (HWCAP): CondM (new XAFLAG and AXFLAG instructions for floating point comparison flags manipulation) and FRINT (rounding floating point numbers to integers) - Re-instate ARM64_PSEUDO_NMI support which was previously marked as BROKEN due to some bugs (now fixed) - Improve parking of stopped CPUs and implement an arm64-specific panic_smp_self_stop() to avoid warning on not being able to stop secondary CPUs during panic - perf: enable the ARM Statistical Profiling Extensions (SPE) on ACPI platforms - perf: DDR performance monitor support for iMX8QXP - cache_line_size() can now be set from DT or ACPI/PPTT if provided to cope with a system cache info not exposed via the CPUID registers - Avoid warning on hardware cache line size greater than ARCH_DMA_MINALIGN if the system is fully coherent - arm64 do_page_fault() and hugetlb cleanups - Refactor set_pte_at() to avoid redundant READ_ONCE(*ptep) - Ignore ACPI 5.1 FADTs reported as 5.0 (infer from the 'arm_boot_flags' introduced in 5.1) - CONFIG_RANDOMIZE_BASE now enabled in defconfig - Allow the selection of ARM64_MODULE_PLTS, currently only done via RANDOMIZE_BASE (and an erratum workaround), allowing modules to spill over into the vmalloc area - Make ZONE_DMA32 configurable * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (54 commits) perf: arm_spe: Enable ACPI/Platform automatic module loading arm_pmu: acpi: spe: Add initial MADT/SPE probing ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens ACPI/PPTT: Modify node flag detection to find last IDENTICAL x86/entry: Simplify _TIF_SYSCALL_EMU handling arm64: rename dump_instr as dump_kernel_instr arm64/mm: Drop [PTE|PMD]_TYPE_FAULT arm64: Implement panic_smp_self_stop() arm64: Improve parking of stopped CPUs arm64: Expose FRINT capabilities to userspace arm64: Expose ARMv8.5 CondM capability to userspace arm64: defconfig: enable CONFIG_RANDOMIZE_BASE arm64: ARM64_MODULES_PLTS must depend on MODULES arm64: bpf: do not allocate executable memory arm64/kprobes: set VM_FLUSH_RESET_PERMS on kprobe instruction pages arm64/mm: wire up CONFIG_ARCH_HAS_SET_DIRECT_MAP arm64: module: create module allocations without exec permissions arm64: Allow user selection of ARM64_MODULE_PLTS acpi/arm64: ignore 5.1 FADTs that are reported as 5.0 arm64: Allow selecting Pseudo-NMI again ...
2019-06-19treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234Thomas Gleixner
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>
2019-06-13arm64/sve: Fix missing SVE/FPSIMD endianness conversionsDave Martin
The in-memory representation of SVE and FPSIMD registers is different: the FPSIMD V-registers are stored as single 128-bit host-endian values, whereas SVE registers are stored in an endianness-invariant byte order. This means that the two representations differ when running on a big-endian host. But we blindly copy data from one representation to another when converting between the two, resulting in the register contents being unintentionally byteswapped in certain situations. Currently this can be triggered by the first SVE instruction after a syscall, for example (though the potential trigger points may vary in future). So, fix the conversion functions fpsimd_to_sve(), sve_to_fpsimd() and sve_sync_from_fpsimd_zeropad() to swab where appropriate. There is no common swahl128() or swab128() that we could use here. Maybe it would be worth making this generic, but for now add a simple local hack. Since the byte order differences are exposed in ABI, also clarify the documentation. Cc: Alex Bennée <alex.bennee@linaro.org> Cc: Peter Maydell <peter.maydell@linaro.org> Cc: Alan Hayward <alan.hayward@arm.com> Cc: Julien Grall <julien.grall@arm.com> Fixes: bc0ee4760364 ("arm64/sve: Core task context handling") Fixes: 8cd969d28fd2 ("arm64/sve: Signal handling support") Fixes: 43d4da2c45b2 ("arm64/sve: ptrace and ELF coredump support") Signed-off-by: Dave Martin <Dave.Martin@arm.com> [will: Fix typos in comments and docs spotted by Julien] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-06-04arm64/fpsimd: Don't disable softirq when touching FPSIMD/SVE stateJulien Grall
When the kernel is compiled with CONFIG_KERNEL_MODE_NEON, some part of the kernel may be able to use FPSIMD/SVE. This is for instance the case for crypto code. Any use of FPSIMD/SVE in the kernel are clearly marked by using the function kernel_neon_{begin, end}. Furthermore, this can only be used when may_use_simd() returns true. The current implementation of may_use_simd() allows softirq to use FPSIMD/SVE unless it is currently in use (i.e kernel_neon_busy is true). When in use, softirqs usually fall back to a software method. At the moment, as a softirq may use FPSIMD/SVE, softirqs are disabled when touching the FPSIMD/SVE context. This has the drawback to disable all softirqs even if they are not using FPSIMD/SVE. Since a softirq is supposed to check may_use_simd() anyway before attempting to use FPSIMD/SVE, there is limited reason to keep softirq disabled when touching the FPSIMD/SVE context. Instead, we can simply disable preemption and mark the FPSIMD/SVE context as in use by setting CPU's fpsimd_context_busy flag. Two new helpers {get, put}_cpu_fpsimd_context are introduced to mark the area using FPSIMD/SVE context and they are used to replace local_bh_{disable, enable}. The functions kernel_neon_{begin, end} are also re-implemented to use the new helpers. Additionally, double-underscored versions of the helpers are provided to called when preemption is already disabled. These are only relevant on paths where irqs are disabled anyway, so they are not needed for correctness in the current code. Let's use them anyway though: this marks critical sections clearly and will help to avoid mistakes during future maintenance. The change has been benchmarked on Linux 5.1-rc4 with defconfig. On Juno2: * hackbench 100 process 1000 (10 times) * .7% quicker On ThunderX 2: * hackbench 1000 process 1000 (20 times) * 3.4% quicker Reviewed-by: Dave Martin <dave.martin@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-06-04arm64/fpsimd: Introduce fpsimd_save_and_flush_cpu_state() and use itJulien Grall
The only external user of fpsimd_save() and fpsimd_flush_cpu_state() is the KVM FPSIMD code. A following patch will introduce a mechanism to acquire owernship of the FPSIMD/SVE context for performing context management operations. Rather than having to export the new helpers to get/put the context, we can just introduce a new function to combine fpsimd_save() and fpsimd_flush_cpu_state(). This has also the advantage to remove any external call of fpsimd_save() and fpsimd_flush_cpu_state(), so they can be turned static. Lastly, the new function can also be used in the PM notifier. Reviewed-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-05-17Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "ARM: - support for SVE and Pointer Authentication in guests - PMU improvements POWER: - support for direct access to the POWER9 XIVE interrupt controller - memory and performance optimizations x86: - support for accessing memory not backed by struct page - fixes and refactoring Generic: - dirty page tracking improvements" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (155 commits) kvm: fix compilation on aarch64 Revert "KVM: nVMX: Expose RDPMC-exiting only when guest supports PMU" kvm: x86: Fix L1TF mitigation for shadow MMU KVM: nVMX: Disable intercept for FS/GS base MSRs in vmcs02 when possible KVM: PPC: Book3S: Remove useless checks in 'release' method of KVM device KVM: PPC: Book3S HV: XIVE: Fix spelling mistake "acessing" -> "accessing" KVM: PPC: Book3S HV: Make sure to load LPID for radix VCPUs kvm: nVMX: Set nested_run_pending in vmx_set_nested_state after checks complete tests: kvm: Add tests for KVM_SET_NESTED_STATE KVM: nVMX: KVM_SET_NESTED_STATE - Tear down old EVMCS state before setting new state tests: kvm: Add tests for KVM_CAP_MAX_VCPUS and KVM_CAP_MAX_CPU_ID tests: kvm: Add tests to .gitignore KVM: Introduce KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 KVM: Fix kvm_clear_dirty_log_protect off-by-(minus-)one KVM: Fix the bitmap range to copy during clear dirty KVM: arm64: Fix ptrauth ID register masking logic KVM: x86: use direct accessors for RIP and RSP KVM: VMX: Use accessors for GPRs outside of dedicated caching logic KVM: x86: Omit caching logic for always-available GPRs kvm, x86: Properly check whether a pfn is an MMIO or not ...
2019-04-18arm64/sve: Clarify vq map semanticsDave Martin
Currently the meanings of sve_vq_map and the ancillary helpers __bit_to_vq() and __vq_to_bit() are not clearly explained. This patch makes the explanatory comment clearer, and removes the duplicate comment from fpsimd.h. The WARN_ON() currently present in __bit_to_vq() confuses the intended use of this helper. Since these are low-level helpers not intended for general-purpose use anyway, it is better not to make guesses about how these functions will be used: rather, this patch removes the WARN_ON() and relies on callers to use the helpers sensibly. Suggested-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-16arm64: HWCAP: add support for AT_HWCAP2Andrew Murray
As we will exhaust the first 32 bits of AT_HWCAP let's start exposing AT_HWCAP2 to userspace to give us up to 64 caps. Whilst it's possible to use the remaining 32 bits of AT_HWCAP, we prefer to expand into AT_HWCAP2 in order to provide a consistent view to userspace between ILP32 and LP64. However internal to the kernel we prefer to continue to use the full space of elf_hwcap. To reduce complexity and allow for future expansion, we now represent hwcaps in the kernel as ordinals and use a KERNEL_HWCAP_ prefix. This allows us to support automatic feature based module loading for all our hwcaps. We introduce cpu_set_feature to set hwcaps which complements the existing cpu_have_feature helper. These helpers allow us to clean up existing direct uses of elf_hwcap and reduce any future effort required to move beyond 64 caps. For convenience we also introduce cpu_{have,set}_named_feature which makes use of the cpu_feature macro to allow providing a hwcap name without a {KERNEL_}HWCAP_ prefix. Signed-off-by: Andrew Murray <andrew.murray@arm.com> [will: use const_ilog2() and tweak documentation] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-03-29arm64/sve: In-kernel vector length availability query interfaceDave Martin
KVM will need to interrogate the set of SVE vector lengths available on the system. This patch exposes the relevant bits to the kernel, along with a sve_vq_available() helper to check whether a particular vector length is supported. __vq_to_bit() and __bit_to_vq() are not intended for use outside these functions: now that these are exposed outside fpsimd.c, they are prefixed with __ in order to provide an extra hint that they are not intended for general-purpose use. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-29arm64/sve: Enable SVE state tracking for non-task contextsDave Martin
The current FPSIMD/SVE context handling support for non-task (i.e., KVM vcpu) contexts does not take SVE into account. This means that only task contexts can safely use SVE at present. In preparation for enabling KVM guests to use SVE, it is necessary to keep track of SVE state for non-task contexts too. This patch adds the necessary support, removing assumptions from the context switch code about the location of the SVE context storage. When binding a vcpu context, its vector length is arbitrarily specified as SVE_VL_MIN for now. In any case, because TIF_SVE is presently cleared at vcpu context bind time, the specified vector length will not be used for anything yet. In later patches TIF_SVE will be set here as appropriate, and the appropriate maximum vector length for the vcpu will be passed when binding. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Julien Grall <julien.grall@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-29arm64/sve: Check SVE virtualisabilityDave Martin
Due to the way the effective SVE vector length is controlled and trapped at different exception levels, certain mismatches in the sets of vector lengths supported by different physical CPUs in the system may prevent straightforward virtualisation of SVE at parity with the host. This patch analyses the extent to which SVE can be virtualised safely without interfering with migration of vcpus between physical CPUs, and rejects late secondary CPUs that would erode the situation further. It is left up to KVM to decide what to do with this information. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-29arm64/sve: Clarify role of the VQ map maintenance functionsDave Martin
The roles of sve_init_vq_map(), sve_update_vq_map() and sve_verify_vq_map() are highly non-obvious to anyone who has not dug through cpufeatures.c in detail. Since the way these functions interact with each other is more important here than a full understanding of the cpufeatures code, this patch adds comments to make the functions' roles clearer. No functional change. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Reviewed-by: Julien Grall <julien.grall@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-29arm64: fpsimd: Always set TIF_FOREIGN_FPSTATE on task state flushDave Martin
This patch updates fpsimd_flush_task_state() to mirror the new semantics of fpsimd_flush_cpu_state() introduced by commit d8ad71fa38a9 ("arm64: fpsimd: Fix TIF_FOREIGN_FPSTATE after invalidating cpu regs"). Both functions now implicitly set TIF_FOREIGN_FPSTATE to indicate that the task's FPSIMD state is not loaded into the cpu. As a side-effect, fpsimd_flush_task_state() now sets TIF_FOREIGN_FPSTATE even for non-running tasks. In the case of non-running tasks this is not useful but also harmless, because the flag is live only while the corresponding task is running. This function is not called from fast paths, so special-casing this for the task == current case is not really worth it. Compiler barriers previously present in restore_sve_fpsimd_context() are pulled into fpsimd_flush_task_state() so that it can be safely called with preemption enabled if necessary. Explicit calls to set TIF_FOREIGN_FPSTATE that accompany fpsimd_flush_task_state() calls and are now redundant are removed as appropriate. fpsimd_flush_task_state() is used to get exclusive access to the representation of the task's state via task_struct, for the purpose of replacing the state. Thus, the call to this function should happen before manipulating fpsimd_state or sve_state etc. in task_struct. Anomalous cases are reordered appropriately in order to make the code more consistent, although there should be no functional difference since these cases are protected by local_bh_disable() anyway. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Julien Grall <julien.grall@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-09-27signal/arm64: Use send_sig_fault where appropriateEric W. Biederman
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-12arm64: move sve_user_{enable,disable} to <asm/fpsimd.h>Mark Rutland
In subsequent patches, we'll want to make use of sve_user_enable() and sve_user_disable() outside of kernel/fpsimd.c. Let's move these to <asm/fpsimd.h> where we can make use of them. To avoid ifdeffery in sequences like: if (system_supports_sve() && some_condition) sve_user_disable(); ... empty stubs are provided when support for SVE is not enabled. Note that system_supports_sve() contains as IS_ENABLED(CONFIG_ARM64_SVE), so the sve_user_disable() call should be optimized away entirely when CONFIG_ARM64_SVE is not selected. To ensure that this is the case, the stub definitions contain a BUILD_BUG(), as we do for other stubs for which calls should always be optimized away when the relevant config option is not selected. At the same time, the include list of <asm/fpsimd.h> is sorted while adding <asm/sysreg.h>. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Dave Martin <dave.martin@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-12arm64: kill change_cpacr()Mark Rutland
Now that we have sysreg_clear_set(), we can use this instead of change_cpacr(). Note that the order of the set and clear arguments differs between change_cpacr() and sysreg_clear_set(), so these are flipped as part of the conversion. Also, sve_user_enable() redundantly clears CPACR_EL1_ZEN_EL0EN before setting it; this is removed for clarity. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Dave Martin <dave.martin@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>