summaryrefslogtreecommitdiff
path: root/Documentation/arm64
AgeCommit message (Collapse)Author
2019-05-03Merge branch 'for-next/perf' of ↵Will Deacon
git://git.kernel.org/pub/scm/linux/kernel/git/will/linux into for-next/core
2019-05-01Merge branch 'for-next/timers' of ↵Will Deacon
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into for-next/core Conflicts: arch/arm64/Kconfig arch/arm64/include/asm/arch_timer.h
2019-04-30arm64: Apply ARM64_ERRATUM_1188873 to Neoverse-N1Marc Zyngier
Neoverse-N1 is also affected by ARM64_ERRATUM_1188873, so let's add it to the list of affected CPUs. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> [will: Update silicon-errata.txt] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-23arm64: Expose SVE2 features for userspaceDave Martin
This patch provides support for reporting the presence of SVE2 and its optional features to userspace. This will also enable visibility of SVE2 for guests, when KVM support for SVE-enabled guests is available. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-04-16arm64: Expose DC CVADP to userspaceAndrew Murray
ARMv8.5 builds upon the ARMv8.2 DC CVAP instruction by introducing a DC CVADP instruction which cleans the data cache to the point of deep persistence. Let's expose this support via the arm64 ELF hwcaps. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Will Deacon <will.deacon@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>
2019-04-04perf/smmuv3: Enable HiSilicon Erratum 162001800 quirkShameer Kolothum
HiSilicon erratum 162001800 describes the limitation of SMMUv3 PMCG implementation on HiSilicon Hip08 platforms. On these platforms, the PMCG event counter registers (SMMU_PMCG_EVCNTRn) are read only and as a result it is not possible to set the initial counter period value on event monitor start. To work around this, the current value of the counter is read and used for delta calculations. OEM information from ACPI header is used to identify the affected hardware platforms. Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com> Reviewed-by: Hanjun Guo <hanjun.guo@linaro.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> [will: update silicon-errata.txt and add reason string to acpi match] Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-03-10Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - Pseudo NMI support for arm64 using GICv3 interrupt priorities - uaccess macros clean-up (unsafe user accessors also merged but reverted, waiting for objtool support on arm64) - ptrace regsets for Pointer Authentication (ARMv8.3) key management - inX() ordering w.r.t. delay() on arm64 and riscv (acks in place by the riscv maintainers) - arm64/perf updates: PMU bindings converted to json-schema, unused variable and misleading comment removed - arm64/debug fixes to ensure checking of the triggering exception level and to avoid the propagation of the UNKNOWN FAR value into the si_code for debug signals - Workaround for Fujitsu A64FX erratum 010001 - lib/raid6 ARM NEON optimisations - NR_CPUS now defaults to 256 on arm64 - Minor clean-ups (documentation/comments, Kconfig warning, unused asm-offsets, clang warnings) - MAINTAINERS update for list information to the ARM64 ACPI entry * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (54 commits) arm64: mmu: drop paging_init comments arm64: debug: Ensure debug handlers check triggering exception level arm64: debug: Don't propagate UNKNOWN FAR into si_code for debug signals Revert "arm64: uaccess: Implement unsafe accessors" arm64: avoid clang warning about self-assignment arm64: Kconfig.platforms: fix warning unmet direct dependencies lib/raid6: arm: optimize away a mask operation in NEON recovery routine lib/raid6: use vdupq_n_u8 to avoid endianness warnings arm64: io: Hook up __io_par() for inX() ordering riscv: io: Update __io_[p]ar() macros to take an argument asm-generic/io: Pass result of I/O accessor to __io_[p]ar() arm64: Add workaround for Fujitsu A64FX erratum 010001 arm64: Rename get_thread_info() arm64: Remove documentation about TIF_USEDFPU arm64: irqflags: Fix clang build warnings arm64: Enable the support of pseudo-NMIs arm64: Skip irqflags tracing for NMI in IRQs disabled context arm64: Skip preemption when exiting an NMI arm64: Handle serror in NMI context irqchip/gic-v3: Allow interrupts to be set as pseudo-NMI ...
2019-02-28arm64: Add workaround for Fujitsu A64FX erratum 010001Zhang Lei
On the Fujitsu-A64FX cores ver(1.0, 1.1), memory access may cause an undefined fault (Data abort, DFSC=0b111111). This fault occurs under a specific hardware condition when a load/store instruction performs an address translation. Any load/store instruction, except non-fault access including Armv8 and SVE might cause this undefined fault. The TCR_ELx.NFD1 bit is used by the kernel when CONFIG_RANDOMIZE_BASE is enabled to mitigate timing attacks against KASLR where the kernel address space could be probed using the FFR and suppressed fault on SVE loads. Since this erratum causes spurious exceptions, which may corrupt the exception registers, we clear the TCR_ELx.NFDx=1 bits when booting on an affected CPU. Signed-off-by: Zhang Lei <zhang.lei@jp.fujitsu.com> [Generated MIDR value/mask for __cpu_setup(), removed spurious-fault handler and always disabled the NFDx bits on affected CPUs] Signed-off-by: James Morse <james.morse@arm.com> Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-02-23clocksource/drivers/arch_timer: Workaround for Allwinner A64 timer instabilitySamuel Holland
The Allwinner A64 SoC is known[1] to have an unstable architectural timer, which manifests itself most obviously in the time jumping forward a multiple of 95 years[2][3]. This coincides with 2^56 cycles at a timer frequency of 24 MHz, implying that the time went slightly backward (and this was interpreted by the kernel as it jumping forward and wrapping around past the epoch). Investigation revealed instability in the low bits of CNTVCT at the point a high bit rolls over. This leads to power-of-two cycle forward and backward jumps. (Testing shows that forward jumps are about twice as likely as backward jumps.) Since the counter value returns to normal after an indeterminate read, each "jump" really consists of both a forward and backward jump from the software perspective. Unless the kernel is trapping CNTVCT reads, a userspace program is able to read the register in a loop faster than it changes. A test program running on all 4 CPU cores that reported jumps larger than 100 ms was run for 13.6 hours and reported the following: Count | Event -------+--------------------------- 9940 | jumped backward 699ms 268 | jumped backward 1398ms 1 | jumped backward 2097ms 16020 | jumped forward 175ms 6443 | jumped forward 699ms 2976 | jumped forward 1398ms 9 | jumped forward 356516ms 9 | jumped forward 357215ms 4 | jumped forward 714430ms 1 | jumped forward 3578440ms This works out to a jump larger than 100 ms about every 5.5 seconds on each CPU core. The largest jump (almost an hour!) was the following sequence of reads: 0x0000007fffffffff → 0x00000093feffffff → 0x0000008000000000 Note that the middle bits don't necessarily all read as all zeroes or all ones during the anomalous behavior; however the low 10 bits checked by the function in this patch have never been observed with any other value. Also note that smaller jumps are much more common, with backward jumps of 2048 (2^11) cycles observed over 400 times per second on each core. (Of course, this is partially explained by lower bits rolling over more frequently.) Any one of these could have caused the 95 year time skip. Similar anomalies were observed while reading CNTPCT (after patching the kernel to allow reads from userspace). However, the CNTPCT jumps are much less frequent, and only small jumps were observed. The same program as before (except now reading CNTPCT) observed after 72 hours: Count | Event -------+--------------------------- 17 | jumped backward 699ms 52 | jumped forward 175ms 2831 | jumped forward 699ms 5 | jumped forward 1398ms Further investigation showed that the instability in CNTPCT/CNTVCT also affected the respective timer's TVAL register. The following values were observed immediately after writing CNVT_TVAL to 0x10000000: CNTVCT | CNTV_TVAL | CNTV_CVAL | CNTV_TVAL Error --------------------+------------+--------------------+----------------- 0x000000d4a2d8bfff | 0x10003fff | 0x000000d4b2d8bfff | +0x00004000 0x000000d4a2d94000 | 0x0fffffff | 0x000000d4b2d97fff | -0x00004000 0x000000d4a2d97fff | 0x10003fff | 0x000000d4b2d97fff | +0x00004000 0x000000d4a2d9c000 | 0x0fffffff | 0x000000d4b2d9ffff | -0x00004000 The pattern of errors in CNTV_TVAL seemed to depend on exactly which value was written to it. For example, after writing 0x10101010: CNTVCT | CNTV_TVAL | CNTV_CVAL | CNTV_TVAL Error --------------------+------------+--------------------+----------------- 0x000001ac3effffff | 0x1110100f | 0x000001ac4f10100f | +0x1000000 0x000001ac40000000 | 0x1010100f | 0x000001ac5110100f | -0x1000000 0x000001ac58ffffff | 0x1110100f | 0x000001ac6910100f | +0x1000000 0x000001ac66000000 | 0x1010100f | 0x000001ac7710100f | -0x1000000 0x000001ac6affffff | 0x1110100f | 0x000001ac7b10100f | +0x1000000 0x000001ac6e000000 | 0x1010100f | 0x000001ac7f10100f | -0x1000000 I was also twice able to reproduce the issue covered by Allwinner's workaround[4], that writing to TVAL sometimes fails, and both CVAL and TVAL are left with entirely bogus values. One was the following values: CNTVCT | CNTV_TVAL | CNTV_CVAL --------------------+------------+-------------------------------------- 0x000000d4a2d6014c | 0x8fbd5721 | 0x000000d132935fff (615s in the past) Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> ======================================================================== Because the CPU can read the CNTPCT/CNTVCT registers faster than they change, performing two reads of the register and comparing the high bits (like other workarounds) is not a workable solution. And because the timer can jump both forward and backward, no pair of reads can distinguish a good value from a bad one. The only way to guarantee a good value from consecutive reads would be to read _three_ times, and take the middle value only if the three values are 1) each unique and 2) increasing. This takes at minimum 3 counter cycles (125 ns), or more if an anomaly is detected. However, since there is a distinct pattern to the bad values, we can optimize the common case (1022/1024 of the time) to a single read by simply ignoring values that match the error pattern. This still takes no more than 3 cycles in the worst case, and requires much less code. As an additional safety check, we still limit the loop iteration to the number of max-frequency (1.2 GHz) CPU cycles in three 24 MHz counter periods. For the TVAL registers, the simple solution is to not use them. Instead, read or write the CVAL and calculate the TVAL value in software. Although the manufacturer is aware of at least part of the erratum[4], there is no official name for it. For now, use the kernel-internal name "UNKNOWN1". [1]: https://github.com/armbian/build/commit/a08cd6fe7ae9 [2]: https://forum.armbian.com/topic/3458-a64-datetime-clock-issue/ [3]: https://irclog.whitequark.org/linux-sunxi/2018-01-26 [4]: https://github.com/Allwinner-Homlet/H6-BSP4.9-linux/blob/master/drivers/clocksource/arm_arch_timer.c#L272 Acked-by: Maxime Ripard <maxime.ripard@bootlin.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Samuel Holland <samuel@sholland.org> Cc: stable@vger.kernel.org Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
2019-02-06irqchip/gic-v3: Detect if GIC can support pseudo-NMIsJulien Thierry
The values non secure EL1 needs to use for PMR and RPR registers depends on the value of SCR_EL3.FIQ. The values non secure EL1 sees from the distributor and redistributor depend on whether security is enabled for the GIC or not. To avoid having to deal with two sets of values for PMR masking/unmasking, only enable pseudo-NMIs when GIC has non-secure view of priorities. Also, add firmware requirements related to SCR_EL3. Signed-off-by: Julien Thierry <julien.thierry@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Cooper <jason@lakedaemon.net> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-02-01arm64: add ptrace regsets for ptrauth key managementKristina Martsenko
Add two new ptrace regsets, which can be used to request and change the pointer authentication keys of a thread. NT_ARM_PACA_KEYS gives access to the instruction/data address keys, and NT_ARM_PACG_KEYS to the generic authentication key. The keys are also part of the core dump file of the process. The regsets are only exposed if the kernel is compiled with CONFIG_CHECKPOINT_RESTORE=y, as the only intended use case is checkpointing and restoring processes that are using pointer authentication. (This can be changed later if there are other use cases.) Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-12-25Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 festive updates from Will Deacon: "In the end, we ended up with quite a lot more than I expected: - Support for ARMv8.3 Pointer Authentication in userspace (CRIU and kernel-side support to come later) - Support for per-thread stack canaries, pending an update to GCC that is currently undergoing review - Support for kexec_file_load(), which permits secure boot of a kexec payload but also happens to improve the performance of kexec dramatically because we can avoid the sucky purgatory code from userspace. Kdump will come later (requires updates to libfdt). - Optimisation of our dynamic CPU feature framework, so that all detected features are enabled via a single stop_machine() invocation - KPTI whitelisting of Cortex-A CPUs unaffected by Meltdown, so that they can benefit from global TLB entries when KASLR is not in use - 52-bit virtual addressing for userspace (kernel remains 48-bit) - Patch in LSE atomics for per-cpu atomic operations - Custom preempt.h implementation to avoid unconditional calls to preempt_schedule() from preempt_enable() - Support for the new 'SB' Speculation Barrier instruction - Vectorised implementation of XOR checksumming and CRC32 optimisations - Workaround for Cortex-A76 erratum #1165522 - Improved compatibility with Clang/LLD - Support for TX2 system PMUS for profiling the L3 cache and DMC - Reflect read-only permissions in the linear map by default - Ensure MMIO reads are ordered with subsequent calls to Xdelay() - Initial support for memory hotplug - Tweak the threshold when we invalidate the TLB by-ASID, so that mremap() performance is improved for ranges spanning multiple PMDs. - Minor refactoring and cleanups" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (125 commits) arm64: kaslr: print PHYS_OFFSET in dump_kernel_offset() arm64: sysreg: Use _BITUL() when defining register bits arm64: cpufeature: Rework ptr auth hwcaps using multi_entry_cap_matches arm64: cpufeature: Reduce number of pointer auth CPU caps from 6 to 4 arm64: docs: document pointer authentication arm64: ptr auth: Move per-thread keys from thread_info to thread_struct arm64: enable pointer authentication arm64: add prctl control for resetting ptrauth keys arm64: perf: strip PAC when unwinding userspace arm64: expose user PAC bit positions via ptrace arm64: add basic pointer authentication support arm64/cpufeature: detect pointer authentication arm64: Don't trap host pointer auth use to EL2 arm64/kvm: hide ptrauth from guests arm64/kvm: consistently handle host HCR_EL2 flags arm64: add pointer authentication register bits arm64: add comments about EC exception levels arm64: perf: Treat EXCLUDE_EL* bit definitions as unsigned arm64: kpti: Whitelist Cortex-A CPUs that don't implement the CSV3 field arm64: enable per-task stack canaries ...
2018-12-13arm64: docs: document pointer authenticationMark Rutland
Now that we've added code to support pointer authentication, add some documentation so that people can figure out if/how to use it. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Reviewed-by: Ramana Radhakrishnan <ramana.radhakrishnan@arm.com> Cc: Andrew Jones <drjones@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ramana Radhakrishnan <ramana.radhakrishnan@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-10arm64: Add configuration/documentation for Cortex-A76 erratum 1165522Marc Zyngier
Now that the infrastructure to handle erratum 1165522 is in place, let's make it a selectable option and add the required documentation. Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-11-29arm64: Add workaround for Cortex-A76 erratum 1286807Catalin Marinas
On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual address for a cacheable mapping of a location is being accessed by a core while another core is remapping the virtual address to a new physical page using the recommended break-before-make sequence, then under very rare circumstances TLBI+DSB completes before a read using the translation being invalidated has been observed by other observers. The workaround repeats the TLBI+DSB operation and is shared with the Qualcomm Falkor erratum 1009 Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-10Documentation/arm64: HugeTLB page implementationPunit Agrawal
Arm v8 architecture supports multiple page sizes - 4k, 16k and 64k. Based on the active page size, the Linux port supports corresponding hugepage sizes at PMD and PUD(4k only) levels. In addition, the architecture also supports caching larger sized ranges (composed of multiple entries) at the PTE and PMD level in the TLBs using the contiguous bit. The Linux port makes use of this architectural support to enable additional hugepage sizes. Describe the two different types of hugepages supported by the arm64 kernel and the hugepage sizes enabled by each. Acked-by: Randy Dunlap <rdunlap@infradead.org> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-10arm64: Add silicon-errata.txt entry for ARM erratum 1188873Marc Zyngier
Document that we actually work around ARM erratum 1188873 Fixes: 95b861a4a6d9 ("arm64: arch_timer: Add workaround for ARM erratum 1188873") Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01arm64: docs: Document SSBS HWCAPWill Deacon
We advertise the MRS/MSR instructions for toggling SSBS at EL0 using an HWCAP, so document it along with the others. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-10-01arm64: docs: Fix typos in ELF hwcapsGiacomo Travaglini
Fix some typos in our hwcap documentation, where we refer to the wrong ID register for some of the capabilities. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com> [will: fix amusing binary constants] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-08-29Documentation/arm64/sve: Couple of improvements and typosJulien Grall
- Fix mismatch between SVE registers (Z) and FPSIMD register (V) - Don't prefix the path for [3] with Linux to stay consistent with [1] and [2]. Signed-off-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-04-09Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm updates from Paolo Bonzini: "ARM: - VHE optimizations - EL2 address space randomization - speculative execution mitigations ("variant 3a", aka execution past invalid privilege register access) - bugfixes and cleanups PPC: - improvements for the radix page fault handler for HV KVM on POWER9 s390: - more kvm stat counters - virtio gpu plumbing - documentation - facilities improvements x86: - support for VMware magic I/O port and pseudo-PMCs - AMD pause loop exiting - support for AMD core performance extensions - support for synchronous register access - expose nVMX capabilities to userspace - support for Hyper-V signaling via eventfd - use Enlightened VMCS when running on Hyper-V - allow userspace to disable MWAIT/HLT/PAUSE vmexits - usual roundup of optimizations and nested virtualization bugfixes Generic: - API selftest infrastructure (though the only tests are for x86 as of now)" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (174 commits) kvm: x86: fix a prototype warning kvm: selftests: add sync_regs_test kvm: selftests: add API testing infrastructure kvm: x86: fix a compile warning KVM: X86: Add Force Emulation Prefix for "emulate the next instruction" KVM: X86: Introduce handle_ud() KVM: vmx: unify adjacent #ifdefs x86: kvm: hide the unused 'cpu' variable KVM: VMX: remove bogus WARN_ON in handle_ept_misconfig Revert "KVM: X86: Fix SMRAM accessing even if VM is shutdown" kvm: Add emulation for movups/movupd KVM: VMX: raise internal error for exception during invalid protected mode state KVM: nVMX: Optimization: Dont set KVM_REQ_EVENT when VMExit with nested_run_pending KVM: nVMX: Require immediate-exit when event reinjected to L2 and L1 event pending KVM: x86: Fix misleading comments on handling pending exceptions KVM: x86: Rename interrupt.pending to interrupt.injected KVM: VMX: No need to clear pending NMI/interrupt on inject realmode interrupt x86/kvm: use Enlightened VMCS when running on Hyper-V x86/hyper-v: detect nested features x86/hyper-v: define struct hv_enlightened_vmcs and clean field bits ...
2018-03-26arm64: Add work around for Arm Cortex-A55 Erratum 1024718Suzuki K Poulose
Some variants of the Arm Cortex-55 cores (r0p0, r0p1, r1p0) suffer from an erratum 1024718, which causes incorrect updates when DBM/AP bits in a page table entry is modified without a break-before-make sequence. The work around is to skip enabling the hardware DBM feature on the affected cores. The hardware Access Flag management features is not affected. There are some other cores suffering from this errata, which could be added to the midr_list to trigger the work around. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: ckadabi@codeaurora.org Reviewed-by: Dave Martin <dave.martin@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-19arm64: Expose Arm v8.4 featuresSuzuki K Poulose
Expose the new features introduced by Arm v8.4 extensions to Arm v8-A profile. These include : 1) Data indpendent timing of instructions. (DIT, exposed as HWCAP_DIT) 2) Unaligned atomic instructions and Single-copy atomicity of loads and stores. (AT, expose as HWCAP_USCAT) 3) LDAPR and STLR instructions with immediate offsets (extension to LRCPC, exposed as HWCAP_ILRCPC) 4) Flag manipulation instructions (TS, exposed as HWCAP_FLAGM). Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Dave Martin <dave.martin@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-19arm64: Documentation: cpu-feature-registers: Remove RES0 fieldsSuzuki K Poulose
Remove the invisible RES0 field entries from the table, listing fields in CPU ID feature registers, as : 1) We are only interested in the user visible fields. 2) The field description may not be up-to-date, as the field could be assigned a new meaning. 3) We already explain the rules of the fields which are not visible. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Dave Martin <dave.martin@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-19arm64: KVM: Allow mapping of vectors outside of the RAM regionMarc Zyngier
We're now ready to map our vectors in weird and wonderful locations. On enabling ARM64_HARDEN_EL2_VECTORS, a vector slot gets allocated if this hasn't been already done via ARM64_HARDEN_BRANCH_PREDICTOR and gets mapped outside of the normal RAM region, next to the idmap. That way, being able to obtain VBAR_EL2 doesn't reveal the mapping of the rest of the hypervisor code. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19arm64: Update the KVM memory map documentationMarc Zyngier
Update the documentation to reflect the new tricks we play on the EL2 mappings... 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>
2018-01-30Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "The main theme of this pull request is security covering variants 2 and 3 for arm64. I expect to send additional patches next week covering an improved firmware interface (requires firmware changes) for variant 2 and way for KPTI to be disabled on unaffected CPUs (Cavium's ThunderX doesn't work properly with KPTI enabled because of a hardware erratum). Summary: - Security mitigations: - variant 2: invalidate the branch predictor with a call to secure firmware - variant 3: implement KPTI for arm64 - 52-bit physical address support for arm64 (ARMv8.2) - arm64 support for RAS (firmware first only) and SDEI (software delegated exception interface; allows firmware to inject a RAS error into the OS) - perf support for the ARM DynamIQ Shared Unit PMU - CPUID and HWCAP bits updated for new floating point multiplication instructions in ARMv8.4 - remove some virtual memory layout printks during boot - fix initial page table creation to cope with larger than 32M kernel images when 16K pages are enabled" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (104 commits) arm64: Fix TTBR + PAN + 52-bit PA logic in cpu_do_switch_mm arm64: Turn on KPTI only on CPUs that need it arm64: Branch predictor hardening for Cavium ThunderX2 arm64: Run enable method for errata work arounds on late CPUs arm64: Move BP hardening to check_and_switch_context arm64: mm: ignore memory above supported physical address size arm64: kpti: Fix the interaction between ASID switching and software PAN KVM: arm64: Emulate RAS error registers and set HCR_EL2's TERR & TEA KVM: arm64: Handle RAS SErrors from EL2 on guest exit KVM: arm64: Handle RAS SErrors from EL1 on guest exit KVM: arm64: Save ESR_EL2 on guest SError KVM: arm64: Save/Restore guest DISR_EL1 KVM: arm64: Set an impdef ESR for Virtual-SError using VSESR_EL2. KVM: arm/arm64: mask/unmask daif around VHE guests arm64: kernel: Prepare for a DISR user arm64: Unconditionally enable IESB on exception entry/return for firmware-first arm64: kernel: Survive corrected RAS errors notified by SError arm64: cpufeature: Detect CPU RAS Extentions arm64: sysreg: Move to use definitions for all the SCTLR bits arm64: cpufeature: __this_cpu_has_cap() shouldn't stop early ...
2018-01-14arm64: cpu_errata: Add Kryo to Falkor 1003 errataStephen Boyd
The Kryo CPUs are also affected by the Falkor 1003 errata, so we need to do the same workaround on Kryo CPUs. The MIDR is slightly more complicated here, where the PART number is not always the same when looking at all the bits from 15 to 4. Drop the lower 8 bits and just look at the top 4 to see if it's '2' and then consider those as Kryo CPUs. This covers all the combinations without having to list them all out. Fixes: 38fd94b0275c ("arm64: Work around Falkor erratum 1003") Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-05arm64: v8.4: Support for new floating point multiplication instructionsDongjiu Geng
ARM v8.4 extensions add new neon instructions for performing a multiplication of each FP16 element of one vector with the corresponding FP16 element of a second vector, and to add or subtract this without an intermediate rounding to the corresponding FP32 element in a third vector. This patch detects this feature and let the userspace know about it via a HWCAP bit and MRS emulation. Cc: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Dongjiu Geng <gengdongjiu@huawei.com> Reviewed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-12-12arm64: Add software workaround for Falkor erratum 1041Shanker Donthineni
The ARM architecture defines the memory locations that are permitted to be accessed as the result of a speculative instruction fetch from an exception level for which all stages of translation are disabled. Specifically, the core is permitted to speculatively fetch from the 4KB region containing the current program counter 4K and next 4K. When translation is changed from enabled to disabled for the running exception level (SCTLR_ELn[M] changed from a value of 1 to 0), the Falkor core may errantly speculatively access memory locations outside of the 4KB region permitted by the architecture. The errant memory access may lead to one of the following unexpected behaviors. 1) A System Error Interrupt (SEI) being raised by the Falkor core due to the errant memory access attempting to access a region of memory that is protected by a slave-side memory protection unit. 2) Unpredictable device behavior due to a speculative read from device memory. This behavior may only occur if the instruction cache is disabled prior to or coincident with translation being changed from enabled to disabled. The conditions leading to this erratum will not occur when either of the following occur: 1) A higher exception level disables translation of a lower exception level (e.g. EL2 changing SCTLR_EL1[M] from a value of 1 to 0). 2) An exception level disabling its stage-1 translation if its stage-2 translation is enabled (e.g. EL1 changing SCTLR_EL1[M] from a value of 1 to 0 when HCR_EL2[VM] has a value of 1). To avoid the errant behavior, software must execute an ISB immediately prior to executing the MSR that will change SCTLR_ELn[M] from 1 to 0. Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-15Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Will Deacon: "The big highlight is support for the Scalable Vector Extension (SVE) which required extensive ABI work to ensure we don't break existing applications by blowing away their signal stack with the rather large new vector context (<= 2 kbit per vector register). There's further work to be done optimising things like exception return, but the ABI is solid now. Much of the line count comes from some new PMU drivers we have, but they're pretty self-contained and I suspect we'll have more of them in future. Plenty of acronym soup here: - initial support for the Scalable Vector Extension (SVE) - improved handling for SError interrupts (required to handle RAS events) - enable GCC support for 128-bit integer types - remove kernel text addresses from backtraces and register dumps - use of WFE to implement long delay()s - ACPI IORT updates from Lorenzo Pieralisi - perf PMU driver for the Statistical Profiling Extension (SPE) - perf PMU driver for Hisilicon's system PMUs - misc cleanups and non-critical fixes" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (97 commits) arm64: Make ARMV8_DEPRECATED depend on SYSCTL arm64: Implement __lshrti3 library function arm64: support __int128 on gcc 5+ arm64/sve: Add documentation arm64/sve: Detect SVE and activate runtime support arm64/sve: KVM: Hide SVE from CPU features exposed to guests arm64/sve: KVM: Treat guest SVE use as undefined instruction execution arm64/sve: KVM: Prevent guests from using SVE arm64/sve: Add sysctl to set the default vector length for new processes arm64/sve: Add prctl controls for userspace vector length management arm64/sve: ptrace and ELF coredump support arm64/sve: Preserve SVE registers around EFI runtime service calls arm64/sve: Preserve SVE registers around kernel-mode NEON use arm64/sve: Probe SVE capabilities and usable vector lengths arm64: cpufeature: Move sys_caps_initialised declarations arm64/sve: Backend logic for setting the vector length arm64/sve: Signal handling support arm64/sve: Support vector length resetting for new processes arm64/sve: Core task context handling arm64/sve: Low-level CPU setup ...
2017-11-03arm64/sve: Add documentationDave Martin
This patch adds basic documentation of the user/kernel interface provided by the for SVE. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Alan Hayward <alan.hayward@arm.com> Cc: Alex Bennée <alex.bennee@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Szabolcs Nagy <szabolcs.nagy@arm.com> Cc: linux-api@vger.kernel.org Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-11-03arm64/sve: Detect SVE and activate runtime supportDave Martin
This patch enables detection of hardware SVE support via the cpufeatures framework, and reports its presence to the kernel and userspace via the new ARM64_SVE cpucap and HWCAP_SVE hwcap respectively. Userspace can also detect SVE using ID_AA64PFR0_EL1, using the cpufeatures MRS emulation. When running on hardware that supports SVE, this enables runtime kernel support for SVE, and allows user tasks to execute SVE instructions and make of the of the SVE-specific user/kernel interface extensions implemented by this series. Signed-off-by: Dave Martin <Dave.Martin@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-19irqchip/gic-v3-its: Workaround HiSilicon Hip07 redistributor addressingMarc Zyngier
The ITSes on the Hip07 (as present in the Huawei D05) are broken when it comes to addressing the redistributors, and need to be explicitely told to address the VLPI page instead of the redistributor base address. So let's add yet another quirk, fixing up the target address in the command stream. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-10-11arm64: docs: describe ELF hwcapsMark Rutland
We don't document our ELF hwcaps, leaving developers to interpret them according to hearsay, guesswork, or (in exceptional cases) inspection of the current kernel code. This is less than optimal, and it would be far better if we had some definitive description of each of the ELF hwcaps that developers could refer to. This patch adds a document describing the (native) arm64 ELF hwcaps. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> [ Updated new hwcap entries in the document ] Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-11arm64: Expose support for optional ARMv8-A featuresSuzuki K Poulose
ARMv8-A adds a few optional features for ARMv8.2 and ARMv8.3. Expose them to the userspace via HWCAPs and mrs emulation. SHA2-512 - Instruction support for SHA512 Hash algorithm (e.g SHA512H, SHA512H2, SHA512U0, SHA512SU1) SHA3 - SHA3 crypto instructions (EOR3, RAX1, XAR, BCAX). SM3 - Instruction support for Chinese cryptography algorithm SM3 SM4 - Instruction support for Chinese cryptography algorithm SM4 DP - Dot Product instructions (UDOT, SDOT). Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Dave Martin <dave.martin@arm.com> Cc: Marc Zyngier <marc.zyngier@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>
2017-10-02arm64: fix documentation on kernel pages mappings to HYP VAYury Norov
The Documentation/arm64/memory.txt says: When using KVM, the hypervisor maps kernel pages in EL2, at a fixed offset from the kernel VA (top 24bits of the kernel VA set to zero): In fact, kernel addresses are transleted to HYP with kern_hyp_va macro, which has more options, and none of them assumes clearing of top 24bits of the kernel VA. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Yury Norov <ynorov@caviumnetworks.com> [will: removed gory details] Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-08-09arm64: Expose DC CVAP to userspaceRobin Murphy
The ARMv8.2-DCPoP feature introduces persistent memory support to the architecture, by defining a point of persistence in the memory hierarchy, and a corresponding cache maintenance operation, DC CVAP. Expose the support via HWCAP and MRS emulation. Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-07-12Merge tag 'iommu-updates-v4.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu Pull IOMMU updates from Joerg Roedel: "This update comes with: - Support for lockless operation in the ARM io-pgtable code. This is an important step to solve the scalability problems in the common dma-iommu code for ARM - Some Errata workarounds for ARM SMMU implemenations - Rewrite of the deferred IO/TLB flush code in the AMD IOMMU driver. The code suffered from very high flush rates, with the new implementation the flush rate is down to ~1% of what it was before - Support for amd_iommu=off when booting with kexec. The problem here was that the IOMMU driver bailed out early without disabling the iommu hardware, if it was enabled in the old kernel - The Rockchip IOMMU driver is now available on ARM64 - Align the return value of the iommu_ops->device_group call-backs to not miss error values - Preempt-disable optimizations in the Intel VT-d and common IOVA code to help Linux-RT - Various other small cleanups and fixes" * tag 'iommu-updates-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (60 commits) iommu/vt-d: Constify intel_dma_ops iommu: Warn once when device_group callback returns NULL iommu/omap: Return ERR_PTR in device_group call-back iommu: Return ERR_PTR() values from device_group call-backs iommu/s390: Use iommu_group_get_for_dev() in s390_iommu_add_device() iommu/vt-d: Don't disable preemption while accessing deferred_flush() iommu/iova: Don't disable preempt around this_cpu_ptr() iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126 iommu/arm-smmu-v3: Enable ACPI based HiSilicon CMD_PREFETCH quirk(erratum 161010701) iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74 ACPI/IORT: Fixup SMMUv3 resource size for Cavium ThunderX2 SMMUv3 model iommu/arm-smmu-v3, acpi: Add temporary Cavium SMMU-V3 IORT model number definitions iommu/io-pgtable-arm: Use dma_wmb() instead of wmb() when publishing table iommu/io-pgtable: depend on !GENERIC_ATOMIC64 when using COMPILE_TEST with LPAE iommu/arm-smmu-v3: Remove io-pgtable spinlock iommu/arm-smmu: Remove io-pgtable spinlock iommu/io-pgtable-arm-v7s: Support lockless operation iommu/io-pgtable-arm: Support lockless operation iommu/io-pgtable: Introduce explicit coherency iommu/io-pgtable-arm-v7s: Refactor split_blk_unmap ...
2017-06-23iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126Geetha Sowjanya
Cavium ThunderX2 SMMU doesn't support MSI and also doesn't have unique irq lines for gerror, eventq and cmdq-sync. New named irq "combined" is set as a errata workaround, which allows to share the irq line by register single irq handler for all the interrupts. Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Geetha sowjanya <gakula@caviumnetworks.com> [will: reworked irq equality checking and added SPI check] Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-23iommu/arm-smmu-v3: Enable ACPI based HiSilicon CMD_PREFETCH quirk(erratum ↵shameer
161010701) HiSilicon SMMUv3 on Hip06/Hip07 platforms doesn't support CMD_PREFETCH command. The dt based support for this quirk is already present in the driver(hisilicon,broken-prefetch-cmd). This adds ACPI support for the quirk using the IORT smmu model number. Signed-off-by: shameer <shameerali.kolothum.thodi@huawei.com> Signed-off-by: hanjun <guohanjun@huawei.com> [will: rewrote patch] Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-23iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74Linu Cherian
Cavium ThunderX2 SMMU implementation doesn't support page 1 register space and PAGE0_REGS_ONLY option is enabled as an errata workaround. This option when turned on, replaces all page 1 offsets used for EVTQ_PROD/CONS, PRIQ_PROD/CONS register access with page 0 offsets. SMMU resource size checks are now based on SMMU option PAGE0_REGS_ONLY, since resource size can be either 64k/128k. For this, arm_smmu_device_dt_probe/acpi_probe has been moved before platform_get_resource call, so that SMMU options are set beforehand. Signed-off-by: Linu Cherian <linu.cherian@cavium.com> Signed-off-by: Geetha Sowjanya <geethasowjanya.akula@cavium.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-06-15arm64: Add workaround for Cavium Thunder erratum 30115David Daney
Some Cavium Thunder CPUs suffer a problem where a KVM guest may inadvertently cause the host kernel to quit receiving interrupts. Use the Group-0/1 trapping in order to deal with it. [maz]: Adapted patch to the Group-0/1 trapping, reworked commit log Tested-by: Alexander Graf <agraf@suse.de> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: David Daney <david.daney@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-09arm64: documentation: document tagged pointer stack constraintsKristina Martsenko
Some kernel features don't currently work if a task puts a non-zero address tag in its stack pointer, frame pointer, or frame record entries (FP, LR). For example, with a tagged stack pointer, the kernel can't deliver signals to the process, and the task is killed instead. As another example, with a tagged frame pointer or frame records, perf fails to generate call graphs or resolve symbols. For now, just document these limitations, instead of finding and fixing everything that doesn't work, as it's not known if anyone needs to use tags in these places anyway. In addition, as requested by Dave Martin, generalize the limitations into a general kernel address tag policy, and refactor tagged-pointers.txt to include it. Fixes: d50240a5f6ce ("arm64: mm: permit use of tagged pointers at EL0") Cc: <stable@vger.kernel.org> # 3.12.x- Reviewed-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-04-07Merge tag 'arch-timer-errata-prereq' of ↵Catalin Marinas
git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into for-next/core Pre-requisites for the arch timer errata workarounds: - Allow checking of a CPU-local erratum - Add CNTVCT_EL0 trap handler - Define Cortex-A73 MIDR - Allow an erratum to be match for all revisions of a core - Add capability to advertise Cortex-A73 erratum 858921 * tag 'arch-timer-errata-prereq' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms: arm64: cpu_errata: Add capability to advertise Cortex-A73 erratum 858921 arm64: cpu_errata: Allow an erratum to be match for all revisions of a core arm64: Define Cortex-A73 MIDR arm64: Add CNTVCT_EL0 trap handler arm64: Allow checking of a CPU-local erratum
2017-04-07arm64: cpu_errata: Add capability to advertise Cortex-A73 erratum 858921Marc Zyngier
In order to work around Cortex-A73 erratum 858921 in a subsequent patch, add the required capability that advertise the erratum. As the configuration option it depends on is not present yet, this has no immediate effect. Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-03-20arm64: v8.3: Support for weaker release consistencySuzuki K Poulose
ARMv8.3 adds new instructions to support Release Consistent processor consistent (RCpc) model, which is weaker than the RCsc model. Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-03-20arm64: v8.3: Support for complex number instructionsSuzuki K Poulose
ARM v8.3 adds support for new instructions to aid floating-point multiplication and addition of complex numbers. Expose the support via HWCAP and MRS emulation Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-03-20arm64: v8.3: Support for Javascript conversion instructionSuzuki K Poulose
ARMv8.3 adds support for a new instruction to perform conversion from double precision floating point to integer to match the architected behaviour of the equivalent Javascript conversion. Expose the availability via HWCAP and MRS emulation. Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>