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2017-03-10arm64: use const cap for system_uses_ttbr0_pan()Mark Rutland
Since commit 4b65a5db362783ab ("arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1"), system_uses_ttbr0_pan() has used cpus_have_cap() to determine whether PAN is present. Since commit a4023f682739439b ("arm64: Add hypervisor safe helper for checking constant capabilities"), which was introduced around the same time, cpus_have_cap() doesn't try to use a static key, and must always perform a load, test, and consitional branch (likely a tbnz for the latter two). Elsewhere, we moved to using cpus_have_const_cap(), which can use a static key (i.e. a non-conditional branch), which is patched at runtime when the feature is detected. This patch makes system_uses_ttbr0_pan() use cpus_have_const_cap(). The static key is likely a win for hot-paths like the uacccess primitives, and this makes our usage consistent regardless. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-02-24arm64/cpufeature: check correct field width when updating sys_valMark Rutland
When we're updating a register's sys_val, we use arm64_ftr_value() to find the new field value. We use cpuid_feature_extract_field() to find the new value, but this implicitly assumes a 4-bit field, so we may extract more bits than we mean to for fields like CTR_EL0.L1ip. This affects update_cpu_ftr_reg(), where we may extract erroneous values for ftr_cur and ftr_new. Depending on the additional bits extracted in either case, we may erroneously detect that the value is mismatched, and we'll try to compute a new safe value. Dependent on these extra bits and feature type, arm64_ftr_safe_value() may pessimistically select the always-safe value, or may erroneously choose either the extracted cur or new value as the safe option. The extra bits will subsequently be masked out in arm64_ftr_set_value(), so we may choose a higher value, yet write back a lower one. Fix this by passing the width down explicitly in arm64_ftr_value(), so we always extract the correct amount. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-10arm64: cpufeature: Track user visible fieldsSuzuki K Poulose
Track the user visible fields of a CPU feature register. This will be used for exposing the value to the userspace. All the user visible fields of a feature register will be passed on as it is, while the others would be filled with their respective safe value. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-10arm64: cpufeature: Document the rules of safe value for featuresSuzuki K Poulose
Document the rules for choosing the safe value for different types of features. Cc: Dave Martin <dave.martin@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-12-13Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - struct thread_info moved off-stack (also touching include/linux/thread_info.h and include/linux/restart_block.h) - cpus_have_cap() reworked to avoid __builtin_constant_p() for static key use (also touching drivers/irqchip/irq-gic-v3.c) - uprobes support (currently only for native 64-bit tasks) - Emulation of kernel Privileged Access Never (PAN) using TTBR0_EL1 switching to a reserved page table - CPU capacity information passing via DT or sysfs (used by the scheduler) - support for systems without FP/SIMD (IOW, kernel avoids touching these registers; there is no soft-float ABI, nor kernel emulation for AArch64 FP/SIMD) - handling of hardware watchpoint with unaligned addresses, varied lengths and offsets from base - use of the page table contiguous hint for kernel mappings - hugetlb fixes for sizes involving the contiguous hint - remove unnecessary I-cache invalidation in flush_cache_range() - CNTHCTL_EL2 access fix for CPUs with VHE support (ARMv8.1) - boot-time checks for writable+executable kernel mappings - simplify asm/opcodes.h and avoid including the 32-bit ARM counterpart and make the arm64 kernel headers self-consistent (Xen headers patch merged separately) - Workaround for broken .inst support in certain binutils versions * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (60 commits) arm64: Disable PAN on uaccess_enable() arm64: Work around broken .inst when defective gas is detected arm64: Add detection code for broken .inst support in binutils arm64: Remove reference to asm/opcodes.h arm64: Get rid of asm/opcodes.h arm64: smp: Prevent raw_smp_processor_id() recursion arm64: head.S: Fix CNTHCTL_EL2 access on VHE system arm64: Remove I-cache invalidation from flush_cache_range() arm64: Enable HIBERNATION in defconfig arm64: Enable CONFIG_ARM64_SW_TTBR0_PAN arm64: xen: Enable user access before a privcmd hvc call arm64: Handle faults caused by inadvertent user access with PAN enabled arm64: Disable TTBR0_EL1 during normal kernel execution arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1 arm64: Factor out TTBR0_EL1 post-update workaround into a specific asm macro arm64: Factor out PAN enabling/disabling into separate uaccess_* macros arm64: Update the synchronous external abort fault description selftests: arm64: add test for unaligned/inexact watchpoint handling arm64: Allow hw watchpoint of length 3,5,6 and 7 arm64: hw_breakpoint: Handle inexact watchpoint addresses ...
2016-11-21arm64: Introduce uaccess_{disable,enable} functionality based on TTBR0_EL1Catalin Marinas
This patch adds the uaccess macros/functions to disable access to user space by setting TTBR0_EL1 to a reserved zeroed page. Since the value written to TTBR0_EL1 must be a physical address, for simplicity this patch introduces a reserved_ttbr0 page at a constant offset from swapper_pg_dir. The uaccess_disable code uses the ttbr1_el1 value adjusted by the reserved_ttbr0 offset. Enabling access to user is done by restoring TTBR0_EL1 with the value from the struct thread_info ttbr0 variable. Interrupts must be disabled during the uaccess_ttbr0_enable code to ensure the atomicity of the thread_info.ttbr0 read and TTBR0_EL1 write. This patch also moves the get_thread_info asm macro from entry.S to assembler.h for reuse in the uaccess_ttbr0_* macros. Cc: Will Deacon <will.deacon@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-11-16arm64: Support systems without FP/ASIMDSuzuki K Poulose
The arm64 kernel assumes that FP/ASIMD units are always present and accesses the FP/ASIMD specific registers unconditionally. This could cause problems when they are absent. This patch adds the support for kernel handling systems without FP/ASIMD by skipping the register access within the kernel. For kvm, we trap the accesses to FP/ASIMD and inject an undefined instruction exception to the VM. The callers of the exported kernel_neon_begin_partial() should make sure that the FP/ASIMD is supported. Cc: Will Deacon <will.deacon@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> [catalin.marinas@arm.com: add comment on the ARM64_HAS_NO_FPSIMD conflict and the new location] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-11-16arm64: Add hypervisor safe helper for checking constant capabilitiesSuzuki K Poulose
The hypervisor may not have full access to the kernel data structures and hence cannot safely use cpus_have_cap() helper for checking the system capability. Add a safe helper for hypervisors to check a constant system capability, which *doesn't* fall back to checking the bitmap maintained by the kernel. With this, make the cpus_have_cap() only check the bitmask and force constant cap checks to use the new API for quicker checks. Cc: Robert Ritcher <rritcher@cavium.com> Cc: Tirumalesh Chalamarla <tchalamarla@cavium.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-11-05arm64: Fix circular include of asm/lse.h through linux/jump_label.hCatalin Marinas
Commit efd9e03facd0 ("arm64: Use static keys for CPU features") introduced support for static keys in asm/cpufeature.h, including linux/jump_label.h. When CC_HAVE_ASM_GOTO is not defined, this causes a circular dependency via linux/atomic.h, asm/lse.h and asm/cpufeature.h. This patch moves the capability macros out out of asm/cpufeature.h into a separate asm/cpucaps.h and modifies some of the #includes accordingly. Fixes: efd9e03facd0 ("arm64: Use static keys for CPU features") Reported-by: Artem Savkov <asavkov@redhat.com> Tested-by: Artem Savkov <asavkov@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-10-20arm64: cpufeature: Schedule enable() calls instead of calling them via IPIJames Morse
The enable() call for a cpufeature/errata is called using on_each_cpu(). This issues a cross-call IPI to get the work done. Implicitly, this stashes the running PSTATE in SPSR when the CPU receives the IPI, and restores it when we return. This means an enable() call can never modify PSTATE. To allow PAN to do this, change the on_each_cpu() call to use stop_machine(). This schedules the work on each CPU which allows us to modify PSTATE. This involves changing the protype of all the enable() functions. enable_cpu_capabilities() is called during boot and enables the feature on all online CPUs. This path now uses stop_machine(). CPU features for hotplug'd CPUs are enabled by verify_local_cpu_features() which only acts on the local CPU, and can already modify the running PSTATE as it is called from secondary_start_kernel(). Reported-by: Tony Thompson <anthony.thompson@arm.com> Reported-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: Work around systems with mismatched cache line sizesSuzuki K Poulose
Systems with differing CPU i-cache/d-cache line sizes can cause problems with the cache management by software when the execution is migrated from one to another. Usually, the application reads the cache size on a CPU and then uses that length to perform cache operations. However, if it gets migrated to another CPU with a smaller cache line size, things could go completely wrong. To prevent such cases, always use the smallest cache line size among the CPUs. The kernel CPU feature infrastructure already keeps track of the safe value for all CPUID registers including CTR. This patch works around the problem by : For kernel, dynamically patch the kernel to read the cache size from the system wide copy of CTR_EL0. For applications, trap read accesses to CTR_EL0 (by clearing the SCTLR.UCT) and emulate the mrs instruction to return the system wide safe value of CTR_EL0. For faster access (i.e, avoiding to lookup the system wide value of CTR_EL0 via read_system_reg), we keep track of the pointer to table entry for CTR_EL0 in the CPU feature infrastructure. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: Rearrange CPU errata workaround checksSuzuki K Poulose
Right now we run through the work around checks on a CPU from __cpuinfo_store_cpu. There are some problems with that: 1) We initialise the system wide CPU feature registers only after the Boot CPU updates its cpuinfo. Now, if a work around depends on the variance of a CPU ID feature (e.g, check for Cache Line size mismatch), we have no way of performing it cleanly for the boot CPU. 2) It is out of place, invoked from __cpuinfo_store_cpu() in cpuinfo.c. It is not an obvious place for that. This patch rearranges the CPU specific capability(aka work around) checks. 1) At the moment we use verify_local_cpu_capabilities() to check if a new CPU has all the system advertised features. Use this for the secondary CPUs to perform the work around check. For that we rename verify_local_cpu_capabilities() => check_local_cpu_capabilities() which: If the system wide capabilities haven't been initialised (i.e, the CPU is activated at the boot), update the system wide detected work arounds. Otherwise (i.e a CPU hotplugged in later) verify that this CPU conforms to the system wide capabilities. 2) Boot CPU updates the work arounds from smp_prepare_boot_cpu() after we have initialised the system wide CPU feature values. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: Use consistent naming for errata handlingSuzuki K Poulose
This is a cosmetic change to rename the functions dealing with the errata work arounds to be more consistent with their naming. 1) check_local_cpu_errata() => update_cpu_errata_workarounds() check_local_cpu_errata() actually updates the system's errata work arounds. So rename it to reflect the same. 2) verify_local_cpu_errata() => verify_local_cpu_errata_workarounds() Use errata_workarounds instead of _errata. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: Set the safe value for L1 icache policySuzuki K Poulose
Right now we use 0 as the safe value for CTR_EL0:L1Ip, which is not defined at the moment. The safer value for the L1Ip should be the weakest of the policies, which happens to be AIVIVT. While at it, fix the comment about safe_val. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-07arm64: Use static keys for CPU featuresCatalin Marinas
This patch adds static keys transparently for all the cpu_hwcaps features by implementing an array of default-false static keys and enabling them when detected. The cpus_have_cap() check uses the static keys if the feature being checked is a constant, otherwise the compiler generates the bitmap test. Because of the early call to static_branch_enable() via check_local_cpu_errata() -> update_cpu_capabilities(), the jump labels are initialised in cpuinfo_store_boot_cpu(). Cc: Will Deacon <will.deacon@arm.com> Cc: Suzuki K. Poulose <Suzuki.Poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-31arm64: cpufeature: expose arm64_ftr_reg struct for CTR_EL0Ard Biesheuvel
Expose the arm64_ftr_reg struct covering CTR_EL0 outside of cpufeature.o so that other code can refer to it directly (i.e., without performing the binary search) Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-31arm64: cpufeature: constify arm64_ftr_regs arrayArd Biesheuvel
Constify the arm64_ftr_regs array, by moving the mutable arm64_ftr_reg fields out of the array itself. This also streamlines the bsearch, since the entire array can be covered by fewer cachelines. Moving the payload out of the array also allows us to have special explicitly defined struct instance in case other code needs to refer to it directly. Note that this replaces the runtime sorting of the array with a runtime BUG() check whether the array is sorted correctly in the code. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-31arm64: cpufeature: constify arm64_ftr_bits structuresArd Biesheuvel
The arm64_ftr_bits structures are never modified, so make them read-only. Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-08-02Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: - ARM: GICv3 ITS emulation and various fixes. Removal of the old VGIC implementation. - s390: support for trapping software breakpoints, nested virtualization (vSIE), the STHYI opcode, initial extensions for CPU model support. - MIPS: support for MIPS64 hosts (32-bit guests only) and lots of cleanups, preliminary to this and the upcoming support for hardware virtualization extensions. - x86: support for execute-only mappings in nested EPT; reduced vmexit latency for TSC deadline timer (by about 30%) on Intel hosts; support for more than 255 vCPUs. - PPC: bugfixes. * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (302 commits) KVM: PPC: Introduce KVM_CAP_PPC_HTM MIPS: Select HAVE_KVM for MIPS64_R{2,6} MIPS: KVM: Reset CP0_PageMask during host TLB flush MIPS: KVM: Fix ptr->int cast via KVM_GUEST_KSEGX() MIPS: KVM: Sign extend MFC0/RDHWR results MIPS: KVM: Fix 64-bit big endian dynamic translation MIPS: KVM: Fail if ebase doesn't fit in CP0_EBase MIPS: KVM: Use 64-bit CP0_EBase when appropriate MIPS: KVM: Set CP0_Status.KX on MIPS64 MIPS: KVM: Make entry code MIPS64 friendly MIPS: KVM: Use kmap instead of CKSEG0ADDR() MIPS: KVM: Use virt_to_phys() to get commpage PFN MIPS: Fix definition of KSEGX() for 64-bit KVM: VMX: Add VMCS to CPU's loaded VMCSs before VMPTRLD kvm: x86: nVMX: maintain internal copy of current VMCS KVM: PPC: Book3S HV: Save/restore TM state in H_CEDE KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures KVM: arm64: vgic-its: Simplify MAPI error handling KVM: arm64: vgic-its: Make vgic_its_cmd_handle_mapi similar to other handlers KVM: arm64: vgic-its: Turn device_id validation into generic ID validation ...
2016-07-03arm64: Add ARM64_HYP_OFFSET_LOW capabilityMarc Zyngier
As we need to indicate to the rest of the kernel which region of the HYP VA space is safe to use, add a capability that will indicate that KVM should use the [VA_BITS-2:0] range. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-07-01arm64: errata: Calling enable functions for CPU errata tooAndre Przywara
Currently we call the (optional) enable function for CPU _features_ only. As CPU _errata_ descriptions share the same data structure and having an enable function is useful for errata as well (for instance to set bits in SCTLR), lets call it when enumerating erratas too. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-04-25arm64: Verify CPU errata work arounds on hotplugged CPUSuzuki K Poulose
CPU Errata work arounds are detected and applied to the kernel code at boot time and the data is then freed up. If a new hotplugged CPU requires a work around which was not applied at boot time, there is nothing we can do but simply fail the booting. Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-25arm64: Allow a capability to be checked on a single CPUMarc Zyngier
Now that the capabilities are only available once all the CPUs have booted, we're unable to check for a particular feature in any subsystem that gets initialized before then. In order to support this, introduce a local_cpu_has_cap() function that tests for the presence of a given capability independently of the whole framework. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> [ Added preemptible() check ] Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> [will: remove duplicate initialisation of caps in this_cpu_has_cap] Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-25arm64: cpufeature: Add scope for capability checkSuzuki K Poulose
Add scope parameter to the arm64_cpu_capabilities::matches(), so that this can be reused for checking the capability on a given CPU vs the system wide. The system uses the default scope associated with the capability for initialising the CPU_HWCAPs and ELF_HWCAPs. Cc: James Morse <james.morse@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Will Deacon <will.deacon@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-20arm64: cpufeature: Track 32bit EL0 supportSuzuki K Poulose
Add cpu_hwcap bit for keeping track of the support for 32bit EL0. Tested-by: Yury Norov <ynorov@caviumnetworks.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-20arm64: Add helpers for detecting AArch32 support at EL0Suzuki K Poulose
Adds a helper to extract the support for AArch32 at EL0 Tested-by: Yury Norov <ynorov@caviumnetworks.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-03-17Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "Here are the main arm64 updates for 4.6. There are some relatively intrusive changes to support KASLR, the reworking of the kernel virtual memory layout and initial page table creation. Summary: - Initial page table creation reworked to avoid breaking large block mappings (huge pages) into smaller ones. The ARM architecture requires break-before-make in such cases to avoid TLB conflicts but that's not always possible on live page tables - Kernel virtual memory layout: the kernel image is no longer linked to the bottom of the linear mapping (PAGE_OFFSET) but at the bottom of the vmalloc space, allowing the kernel to be loaded (nearly) anywhere in physical RAM - Kernel ASLR: position independent kernel Image and modules being randomly mapped in the vmalloc space with the randomness is provided by UEFI (efi_get_random_bytes() patches merged via the arm64 tree, acked by Matt Fleming) - Implement relative exception tables for arm64, required by KASLR (initial code for ARCH_HAS_RELATIVE_EXTABLE added to lib/extable.c but actual x86 conversion to deferred to 4.7 because of the merge dependencies) - Support for the User Access Override feature of ARMv8.2: this allows uaccess functions (get_user etc.) to be implemented using LDTR/STTR instructions. Such instructions, when run by the kernel, perform unprivileged accesses adding an extra level of protection. The set_fs() macro is used to "upgrade" such instruction to privileged accesses via the UAO bit - Half-precision floating point support (part of ARMv8.2) - Optimisations for CPUs with or without a hardware prefetcher (using run-time code patching) - copy_page performance improvement to deal with 128 bytes at a time - Sanity checks on the CPU capabilities (via CPUID) to prevent incompatible secondary CPUs from being brought up (e.g. weird big.LITTLE configurations) - valid_user_regs() reworked for better sanity check of the sigcontext information (restored pstate information) - ACPI parking protocol implementation - CONFIG_DEBUG_RODATA enabled by default - VDSO code marked as read-only - DEBUG_PAGEALLOC support - ARCH_HAS_UBSAN_SANITIZE_ALL enabled - Erratum workaround Cavium ThunderX SoC - set_pte_at() fix for PROT_NONE mappings - Code clean-ups" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (99 commits) arm64: kasan: Fix zero shadow mapping overriding kernel image shadow arm64: kasan: Use actual memory node when populating the kernel image shadow arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission arm64: Fix misspellings in comments. arm64: efi: add missing frame pointer assignment arm64: make mrs_s prefixing implicit in read_cpuid arm64: enable CONFIG_DEBUG_RODATA by default arm64: Rework valid_user_regs arm64: mm: check at build time that PAGE_OFFSET divides the VA space evenly arm64: KVM: Move kvm_call_hyp back to its original localtion arm64: mm: treat memstart_addr as a signed quantity arm64: mm: list kernel sections in order arm64: lse: deal with clobbered IP registers after branch via PLT arm64: mm: dump: Use VA_START directly instead of private LOWEST_ADDR arm64: kconfig: add submenu for 8.2 architectural features arm64: kernel: acpi: fix ioremap in ACPI parking protocol cpu_postboot arm64: Add support for Half precision floating point arm64: Remove fixmap include fragility arm64: Add workaround for Cavium erratum 27456 arm64: mm: Mark .rodata as RO ...
2016-03-04arm64: make mrs_s prefixing implicit in read_cpuidMark Rutland
Commit 0f54b14e76f5302a ("arm64: cpufeature: Change read_cpuid() to use sysreg's mrs_s macro") changed read_cpuid to require a SYS_ prefix on register names, to allow manual assembly of registers unknown by the toolchain, using tables in sysreg.h. This interacts poorly with commit 42b55734030c1f72 ("efi/arm64: Check for h/w support before booting a >4 KB granular kernel"), which is curretly queued via the tip tree, and uses read_cpuid without a SYS_ prefix. Due to this, a build of next-20160304 fails if EFI and 64K pages are selected. To avoid this issue when trees are merged, move the required SYS_ prefixing into read_cpuid, and revert all of the updated callsites to pass plain register names. This effectively reverts the bulk of commit 0f54b14e76f5302a. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-29arm64: Add ARM64_HAS_VIRT_HOST_EXTN featureMarc Zyngier
Add a new ARM64_HAS_VIRT_HOST_EXTN features to indicate that the CPU has the ARMv8.1 VHE capability. This will be used to trigger kernel patching in KVM. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-26arm64: Add workaround for Cavium erratum 27456Andrew Pinski
On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI instructions may cause the icache to become corrupted if it contains data for a non-current ASID. This patch implements the workaround (which invalidates the local icache when switching the mm) by using code patching. Signed-off-by: Andrew Pinski <apinski@cavium.com> Signed-off-by: David Daney <david.daney@cavium.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25arm64: Rename cpuid_feature field extract routinesSuzuki K Poulose
Now that we have a clear understanding of the sign of a feature, rename the routines to reflect the sign, so that it is not misused. The cpuid_feature_extract_field() now accepts a 'sign' parameter. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25arm64: capabilities: Handle sign of the feature bitSuzuki K Poulose
Use the appropriate accessor for the feature bit by keeping track of the sign of the feature Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-25arm64: Enable CPU capability verification unconditionallySuzuki K Poulose
We verify the capabilities of the secondary CPUs only when hotplug is enabled. The boot time activated CPUs do not go through the verification by checking whether the system wide capabilities were initialised or not. This patch removes the capability check dependency on CONFIG_HOTPLUG_CPU, to make sure that all the secondary CPUs go through the check. The boot time activated CPUs will still skip the system wide capability check. The plan is to hook in a check for CPU features used by the kernel at early boot up, based on the Boot CPU values. Cc: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: kernel: Don't toggle PAN on systems with UAOJames Morse
If a CPU supports both Privileged Access Never (PAN) and User Access Override (UAO), we don't need to disable/re-enable PAN round all copy_to_user() like calls. UAO alternatives cause these calls to use the 'unprivileged' load/store instructions, which are overridden to be the privileged kind when fs==KERNEL_DS. This patch changes the copy_to_user() calls to have their PAN toggling depend on a new composite 'feature' ARM64_ALT_PAN_NOT_UAO. If both features are detected, PAN will be enabled, but the copy_to_user() alternatives will not be applied. This means PAN will be enabled all the time for these functions. If only PAN is detected, the toggling will be enabled as normal. This will save the time taken to disable/re-enable PAN, and allow us to catch copy_to_user() accesses that occur with fs==KERNEL_DS. Futex and swp-emulation code continue to hang their PAN toggling code on ARM64_HAS_PAN. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: kernel: Add support for User Access OverrideJames Morse
'User Access Override' is a new ARMv8.2 feature which allows the unprivileged load and store instructions to be overridden to behave in the normal way. This patch converts {get,put}_user() and friends to use ldtr*/sttr* instructions - so that they can only access EL0 memory, then enables UAO when fs==KERNEL_DS so that these functions can access kernel memory. This allows user space's read/write permissions to be checked against the page tables, instead of testing addr<USER_DS, then using the kernel's read/write permissions. Signed-off-by: James Morse <james.morse@arm.com> [catalin.marinas@arm.com: move uao_thread_switch() above dsb()] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-18arm64: cpufeature: Change read_cpuid() to use sysreg's mrs_s macroJames Morse
Older assemblers may not have support for newer feature registers. To get round this, sysreg.h provides a 'mrs_s' macro that takes a register encoding and generates the raw instruction. Change read_cpuid() to use mrs_s in all cases so that new registers don't have to be a special case. Including sysreg.h means we need to move the include and definition of read_cpuid() after the #ifndef __ASSEMBLY__ to avoid syntax errors in vmlinux.lds. 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>
2016-02-16arm64: prefetch: add alternative pattern for CPUs without a prefetcherWill Deacon
Most CPUs have a hardware prefetcher which generally performs better without explicit prefetch instructions issued by software, however some CPUs (e.g. Cavium ThunderX) rely solely on explicit prefetch instructions. This patch adds an alternative pattern (ARM64_HAS_NO_HW_PREFETCH) to allow our library code to make use of explicit prefetch instructions during things like copy routines only when the CPU does not have the capability to perform the prefetching itself. Signed-off-by: Will Deacon <will.deacon@arm.com> Tested-by: Andrew Pinski <apinski@cavium.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-27Merge tag 'arm64-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Catalin Marinas: - Build fix when !CONFIG_UID16 (the patch is touching generic files but it only affects arm64 builds; submitted by Arnd Bergmann) - EFI fixes to deal with early_memremap() returning NULL and correctly mapping run-time regions - Fix CPUID register extraction of unsigned fields (not to be sign-extended) - ASID allocator fix to deal with long-running tasks over multiple generation roll-overs - Revert support for marking page ranges as contiguous PTEs (it leads to TLB conflicts and requires additional non-trivial kernel changes) - Proper early_alloc() failure check - Disable KASan for 48-bit VA and 16KB page configuration (the pgd is larger than the KASan shadow memory) - Update the fault_info table (original descriptions based on early engineering spec) * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: efi: fix initcall return values arm64: efi: deal with NULL return value of early_memremap() arm64: debug: Treat the BRPs/WRPs as unsigned arm64: cpufeature: Track unsigned fields arm64: cpufeature: Add helpers for extracting unsigned values Revert "arm64: Mark kernel page ranges contiguous" arm64: mm: keep reserved ASIDs in sync with mm after multiple rollovers arm64: KASAN depends on !(ARM64_16K_PAGES && ARM64_VA_BITS_48) arm64: efi: correctly map runtime regions arm64: mm: fix fault_info table xFSC decoding arm64: fix building without CONFIG_UID16 arm64: early_alloc: Fix check for allocation failure
2015-11-26arm64: cpufeature: Track unsigned fieldsSuzuki K. Poulose
Some of the feature bits have unsigned values and need to be treated accordingly to avoid errors. Adds the property to the feature bits and use the appropriate field extract helpers. Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-26arm64: cpufeature: Add helpers for extracting unsigned valuesSuzuki K. Poulose
The cpuid_feature_extract_field() extracts the feature value as a signed integer. This could be problematic for features whose values are unsigned. e.g, ID_AA64DFR0_EL1:BRPs. Add an unsigned variant for the unsigned fields. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-24arm64: KVM: Add workaround for Cortex-A57 erratum 834220Marc Zyngier
Cortex-A57 parts up to r1p2 can misreport Stage 2 translation faults when a Stage 1 permission fault or device alignment fault should have been reported. This patch implements the workaround (which is to validate that the Stage-1 translation actually succeeds) by using code patching. Cc: stable@vger.kernel.org Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-04Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - "genirq: Introduce generic irq migration for cpu hotunplugged" patch merged from tip/irq/for-arm to allow the arm64-specific part to be upstreamed via the arm64 tree - CPU feature detection reworked to cope with heterogeneous systems where CPUs may not have exactly the same features. The features reported by the kernel via internal data structures or ELF_HWCAP are delayed until all the CPUs are up (and before user space starts) - Support for 16KB pages, with the additional bonus of a 36-bit VA space, though the latter only depending on EXPERT - Implement native {relaxed, acquire, release} atomics for arm64 - New ASID allocation algorithm which avoids IPI on roll-over, together with TLB invalidation optimisations (using local vs global where feasible) - KASan support for arm64 - EFI_STUB clean-up and isolation for the kernel proper (required by KASan) - copy_{to,from,in}_user optimisations (sharing the memcpy template) - perf: moving arm64 to the arm32/64 shared PMU framework - L1_CACHE_BYTES increased to 128 to accommodate Cavium hardware - Support for the contiguous PTE hint on kernel mapping (16 consecutive entries may be able to use a single TLB entry) - Generic CONFIG_HZ now used on arm64 - defconfig updates * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (91 commits) arm64/efi: fix libstub build under CONFIG_MODVERSIONS ARM64: Enable multi-core scheduler support by default arm64/efi: move arm64 specific stub C code to libstub arm64: page-align sections for DEBUG_RODATA arm64: Fix build with CONFIG_ZONE_DMA=n arm64: Fix compat register mappings arm64: Increase the max granular size arm64: remove bogus TASK_SIZE_64 check arm64: make Timer Interrupt Frequency selectable arm64/mm: use PAGE_ALIGNED instead of IS_ALIGNED arm64: cachetype: fix definitions of ICACHEF_* flags arm64: cpufeature: declare enable_cpu_capabilities as static genirq: Make the cpuhotplug migration code less noisy arm64: Constify hwcap name string arrays arm64/kvm: Make use of the system wide safe values arm64/debug: Make use of the system wide safe value arm64: Move FP/ASIMD hwcap handling to common code arm64/HWCAP: Use system wide safe values arm64/capabilities: Make use of system wide safe value arm64: Delay cpu feature capability checks ...
2015-10-21arm64/HWCAP: Use system wide safe valuesSuzuki K. Poulose
Extend struct arm64_cpu_capabilities to handle the HWCAP detection and make use of the system wide value of the feature registers for a reliable set of HWCAPs. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Tested-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21arm64/capabilities: Make use of system wide safe valueSuzuki K. Poulose
Now that we can reliably read the system wide safe value for a feature register, use that to compute the system capability. This patch also replaces the 'feature-register-specific' methods with a generic routine to check the capability. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Tested-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21arm64: Delay cpu feature capability checksSuzuki K. Poulose
At the moment we run through the arm64_features capability list for each CPU and set the capability if one of the CPU supports it. This could be problematic in a heterogeneous system with differing capabilities. Delay the CPU feature checks until all the enabled CPUs are up(i.e, smp_cpus_done(), so that we can make better decisions based on the overall system capability. Once we decide and advertise the capabilities the alternatives can be applied. From this state, we cannot roll back a feature to disabled based on the values from a new hotplugged CPU, due to the runtime patching and other reasons. So, for all new CPUs, we need to make sure that they have the established system capabilities. Failing which, we bring the CPU down, preventing it from turning online. Once the capabilities are decided, any new CPU booting up goes through verification to ensure that it has all the enabled capabilities and also invokes the respective enable() method on the CPU. The CPU errata checks are not delayed and is still executed per-CPU to detect the respective capabilities. If we ever come across a non-errata capability that needs to be checked on each-CPU, we could introduce them via a new capability table(or introduce a flag), which can be processed per CPU. The next patch will make the feature checks use the system wide safe value of a feature register. NOTE: The enable() methods associated with the capability is scheduled on all the CPUs (which is the only use case at the moment). If we need a different type of 'enable()' which only needs to be run once on any CPU, we should be able to handle that when needed. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Tested-by: Dave Martin <Dave.Martin@arm.com> [catalin.marinas@arm.com: static variable and coding style fixes] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21arm64: Refactor check_cpu_capabilitiesSuzuki K. Poulose
check_cpu_capabilities runs through a given list of caps and checks if the system has the cap, updates the system capability bitmap and also runs any enable() methods associated with them. All of this is not quite obvious from the name 'check'. This patch splits the check_cpu_capabilities into two parts : 1) update_cpu_capabilities => Runs through the given list and updates the system wide capability map. 2) enable_cpu_capabilities => Runs through the given list and invokes enable() (if any) for the caps enabled on the system. Cc: Andre Przywara <andre.przywara@arm.com> Cc: Will Deacon <will.deacon@arm.com> Suggested-by: Catalin Marinas <catalin.marinsa@arm.com> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Tested-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21arm64: Cleanup mixed endian support detectionSuzuki K. Poulose
Make use of the system wide safe register to decide the support for mixed endian. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Tested-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21arm64: Read system wide CPUID valueSuzuki K. Poulose
Add an API for reading the safe CPUID value across the system from the new infrastructure. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Tested-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21arm64: Keep track of CPU feature registersSuzuki K. Poulose
This patch adds an infrastructure to keep track of the CPU feature registers on the system. For each register, the infrastructure keeps track of the system wide safe value of the feature bits. Also, tracks the which fields of a register should be matched strictly across all the CPUs on the system for the SANITY check infrastructure. The feature bits are classified into following 3 types depending on the implication of the possible values. This information is used to decide the safe value for a feature. LOWER_SAFE - The smaller value is safer HIGHER_SAFE - The bigger value is safer EXACT - We can't decide between the two, so a predefined safe_value is used. This infrastructure will be later used to make better decisions for: - Kernel features (e.g, KVM, Debug) - SANITY Check - CPU capability - ELF HWCAP - Exposing CPU Feature register to userspace. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Tested-by: Dave Martin <Dave.Martin@arm.com> [catalin.marinas@arm.com: whitespace fix] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-10-21arm64: Handle width of a cpuid featureSuzuki K. Poulose
Introduce a helper to extract cpuid feature for any given width. Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Tested-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>