summaryrefslogtreecommitdiff
path: root/arch/arm64/kernel/cpu_errata.c
AgeCommit message (Collapse)Author
2018-03-27arm64: cpufeature: Avoid warnings due to unused symbolsWill Deacon
An allnoconfig build complains about unused symbols due to functions that are called via conditional cpufeature and cpu_errata table entries. Annotate these as __maybe_unused if they are likely to be generic, or predicate their compilation on the same option as the table entry if they are specific to a given alternative. Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-26arm64: capabilities: Handle shared entriesSuzuki K Poulose
Some capabilities have different criteria for detection and associated actions based on the matching criteria, even though they all share the same capability bit. So far we have used multiple entries with the same capability bit to handle this. This is prone to errors, as the cpu_enable is invoked for each entry, irrespective of whether the detection rule applies to the CPU or not. And also this complicates other helpers, e.g, __this_cpu_has_cap. This patch adds a wrapper entry to cover all the possible variations of a capability by maintaining list of matches + cpu_enable callbacks. To avoid complicating the prototypes for the "matches()", we use arm64_cpu_capabilities maintain the list and we ignore all the other fields except the matches & cpu_enable. This ensures : 1) The capabilitiy is set when at least one of the entry detects 2) Action is only taken for the entries that "matches". This avoids explicit checks in the cpu_enable() take some action. The only constraint here is that, all the entries should have the same "type" (i.e, scope and conflict rules). If a cpu_enable() method is associated with multiple matches for a single capability, care should be taken that either the match criteria are mutually exclusive, or that the method is robust against being called multiple times. This also reverts the changes introduced by commit 67948af41f2e6818ed ("arm64: capabilities: Handle duplicate entries for a capability"). Cc: Robin Murphy <robin.murphy@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>
2018-03-26arm64: capabilities: Add support for checks based on a list of MIDRsSuzuki K Poulose
Add helpers for detecting an errata on list of midr ranges of affected CPUs, with the same work around. Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.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>
2018-03-26arm64: Add helpers for checking CPU MIDR against a rangeSuzuki K Poulose
Add helpers for checking if the given CPU midr falls in a range of variants/revisions for a given model. Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.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>
2018-03-26arm64: capabilities: Clean up midr range helpersSuzuki K Poulose
We are about to introduce generic MIDR range helpers. Clean up the existing helpers in erratum handling, preparing them to use generic version. Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.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>
2018-03-26arm64: capabilities: Add flags to handle the conflicts on late CPUSuzuki K Poulose
When a CPU is brought up, it is checked against the caps that are known to be enabled on the system (via verify_local_cpu_capabilities()). Based on the state of the capability on the CPU vs. that of System we could have the following combinations of conflict. x-----------------------------x | Type | System | Late CPU | |-----------------------------| | a | y | n | |-----------------------------| | b | n | y | x-----------------------------x Case (a) is not permitted for caps which are system features, which the system expects all the CPUs to have (e.g VHE). While (a) is ignored for all errata work arounds. However, there could be exceptions to the plain filtering approach. e.g, KPTI is an optional feature for a late CPU as long as the system already enables it. Case (b) is not permitted for errata work arounds that cannot be activated after the kernel has finished booting.And we ignore (b) for features. Here, yet again, KPTI is an exception, where if a late CPU needs KPTI we are too late to enable it (because we change the allocation of ASIDs etc). Add two different flags to indicate how the conflict should be handled. ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU - CPUs may have the capability ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU - CPUs may not have the cappability. Now that we have the flags to describe the behavior of the errata and the features, as we treat them, define types for ERRATUM and FEATURE. 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>
2018-03-26arm64: capabilities: Prepare for fine grained capabilitiesSuzuki K Poulose
We use arm64_cpu_capabilities to represent CPU ELF HWCAPs exposed to the userspace and the CPU hwcaps used by the kernel, which include cpu features and CPU errata work arounds. Capabilities have some properties that decide how they should be treated : 1) Detection, i.e scope : A cap could be "detected" either : - if it is present on at least one CPU (SCOPE_LOCAL_CPU) Or - if it is present on all the CPUs (SCOPE_SYSTEM) 2) When is it enabled ? - A cap is treated as "enabled" when the system takes some action based on whether the capability is detected or not. e.g, setting some control register, patching the kernel code. Right now, we treat all caps are enabled at boot-time, after all the CPUs are brought up by the kernel. But there are certain caps, which are enabled early during the boot (e.g, VHE, GIC_CPUIF for NMI) and kernel starts using them, even before the secondary CPUs are brought up. We would need a way to describe this for each capability. 3) Conflict on a late CPU - When a CPU is brought up, it is checked against the caps that are known to be enabled on the system (via verify_local_cpu_capabilities()). Based on the state of the capability on the CPU vs. that of System we could have the following combinations of conflict. x-----------------------------x | Type | System | Late CPU | ------------------------------| | a | y | n | ------------------------------| | b | n | y | x-----------------------------x Case (a) is not permitted for caps which are system features, which the system expects all the CPUs to have (e.g VHE). While (a) is ignored for all errata work arounds. However, there could be exceptions to the plain filtering approach. e.g, KPTI is an optional feature for a late CPU as long as the system already enables it. Case (b) is not permitted for errata work arounds which requires some work around, which cannot be delayed. And we ignore (b) for features. Here, yet again, KPTI is an exception, where if a late CPU needs KPTI we are too late to enable it (because we change the allocation of ASIDs etc). So this calls for a lot more fine grained behavior for each capability. And if we define all the attributes to control their behavior properly, we may be able to use a single table for the CPU hwcaps (which cover errata and features, not the ELF HWCAPs). This is a prepartory step to get there. More bits would be added for the properties listed above. We are going to use a bit-mask to encode all the properties of a capabilities. This patch encodes the "SCOPE" of the capability. As such there is no change in how the capabilities are treated. 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>
2018-03-26arm64: capabilities: Move errata processing codeSuzuki K Poulose
We have errata work around processing code in cpu_errata.c, which calls back into helpers defined in cpufeature.c. Now that we are going to make the handling of capabilities generic, by adding the information to each capability, move the errata work around specific processing code. No functional changes. Cc: Will Deacon <will.deacon@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andre Przywara <andre.przywara@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>
2018-03-26arm64: capabilities: Update prototype for enable call backDave Martin
We issue the enable() call back for all CPU hwcaps capabilities available on the system, on all the CPUs. So far we have ignored the argument passed to the call back, which had a prototype to accept a "void *" for use with on_each_cpu() and later with stop_machine(). However, with commit 0a0d111d40fd1 ("arm64: cpufeature: Pass capability structure to ->enable callback"), there are some users of the argument who wants the matching capability struct pointer where there are multiple matching criteria for a single capability. Clean up the declaration of the call back to make it clear. 1) Renamed to cpu_enable(), to imply taking necessary actions on the called CPU for the entry. 2) Pass const pointer to the capability, to allow the call back to check the entry. (e.,g to check if any action is needed on the CPU) 3) We don't care about the result of the call back, turning this to a void. Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: James Morse <james.morse@arm.com> Acked-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Dave Martin <dave.martin@arm.com> [suzuki: convert more users, rename call back and drop results] Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-19arm64: KVM: Use SMCCC_ARCH_WORKAROUND_1 for Falkor BP hardeningShanker Donthineni
The function SMCCC_ARCH_WORKAROUND_1 was introduced as part of SMC V1.1 Calling Convention to mitigate CVE-2017-5715. This patch uses the standard call SMCCC_ARCH_WORKAROUND_1 for Falkor chips instead of Silicon provider service ID 0xC2001700. Cc: <stable@vger.kernel.org> # 4.14+ Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19arm64: Enable ARM64_HARDEN_EL2_VECTORS on Cortex-A57 and A72Marc Zyngier
Cortex-A57 and A72 are vulnerable to the so-called "variant 3a" of Meltdown, where an attacker can speculatively obtain the value of a privileged system register. By enabling ARM64_HARDEN_EL2_VECTORS on these CPUs, obtaining VBAR_EL2 is not disclosing the hypervisor mappings anymore. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19arm64: Make BP hardening slot counter availableMarc Zyngier
We're about to need to allocate hardening slots from other parts of the kernel (in order to support ARM64_HARDEN_EL2_VECTORS). Turn the counter into an atomic_t and make it available to the rest of the kernel. Also add BP_HARDEN_EL2_SLOTS as the number of slots instead of the hardcoded 4... Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-09arm64: Relax ARM_SMCCC_ARCH_WORKAROUND_1 discoveryMarc Zyngier
A recent update to the ARM SMCCC ARCH_WORKAROUND_1 specification allows firmware to return a non zero, positive value to describe that although the mitigation is implemented at the higher exception level, the CPU on which the call is made is not affected. Let's relax the check on the return value from ARCH_WORKAROUND_1 so that we only error out if the returned value is negative. Fixes: b092201e0020 ("arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support") Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-03-09arm64/kernel: enable A53 erratum #8434319 handling at runtimeArd Biesheuvel
Omit patching of ADRP instruction at module load time if the current CPUs are not susceptible to the erratum. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: Drop duplicate initialisation of .def_scope field] Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-03-09arm64/errata: add REVIDR handling to frameworkArd Biesheuvel
In some cases, core variants that are affected by a certain erratum also exist in versions that have the erratum fixed, and this fact is recorded in a dedicated bit in system register REVIDR_EL1. Since the architecture does not require that a certain bit retains its meaning across different variants of the same model, each such REVIDR bit is tightly coupled to a certain revision/variant value, and so we need a list of revidr_mask/midr pairs to carry this information. So add the struct member and the associated macros and handling to allow REVIDR fixes to be taken into account. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-02-12arm64: Add missing Falkor part number for branch predictor hardeningShanker Donthineni
References to CPU part number MIDR_QCOM_FALKOR were dropped from the mailing list patch due to mainline/arm64 branch dependency. So this patch adds the missing part number. Fixes: ec82b567a74f ("arm64: Implement branch predictor hardening for Falkor") Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-06arm64: Kill PSCI_GET_VERSION as a variant-2 workaroundMarc Zyngier
Now that we've standardised on SMCCC v1.1 to perform the branch prediction invalidation, let's drop the previous band-aid. If vendors haven't updated their firmware to do SMCCC 1.1, they haven't updated PSCI either, so we don't loose anything. Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-06arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening supportMarc Zyngier
Add the detection and runtime code for ARM_SMCCC_ARCH_WORKAROUND_1. It is lovely. Really. Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-23arm64: Branch predictor hardening for Cavium ThunderX2Jayachandran C
Use PSCI based mitigation for speculative execution attacks targeting the branch predictor. We use the same mechanism as the one used for Cortex-A CPUs, we expect the PSCI version call to have a side effect of clearing the BTBs. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jayachandran C <jnair@caviumnetworks.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-23arm64: Run enable method for errata work arounds on late CPUsSuzuki K Poulose
When a CPU is brought up after we have finalised the system wide capabilities (i.e, features and errata), we make sure the new CPU doesn't need a new errata work around which has not been detected already. However we don't run enable() method on the new CPU for the errata work arounds already detected. This could cause the new CPU running without potential work arounds. It is upto the "enable()" method to decide if this CPU should do something about the errata. Fixes: commit 6a6efbb45b7d95c84 ("arm64: Verify CPU errata work arounds on hotplugged CPU") Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Dave Martin <dave.martin@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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>
2018-01-08arm64: Implement branch predictor hardening for FalkorShanker Donthineni
Falkor is susceptible to branch predictor aliasing and can theoretically be attacked by malicious code. This patch implements a mitigation for these attacks, preventing any malicious entries from affecting other victim contexts. Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org> [will: fix label name when !CONFIG_KVM and remove references to MIDR_FALKOR] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-08arm64: Implement branch predictor hardening for affected Cortex-A CPUsWill Deacon
Cortex-A57, A72, A73 and A75 are susceptible to branch predictor aliasing and can theoretically be attacked by malicious code. This patch implements a PSCI-based mitigation for these CPUs when available. The call into firmware will invalidate the branch predictor state, preventing any malicious entries from affecting other victim contexts. Co-developed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-01-08arm64: Add skeleton to harden the branch predictor against aliasing attacksWill Deacon
Aliasing attacks against CPU branch predictors can allow an attacker to redirect speculative control flow on some CPUs and potentially divulge information from one context to another. This patch adds initial skeleton code behind a new Kconfig option to enable implementation-specific mitigations against these attacks for CPUs that are affected. Co-developed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@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>
2017-04-07arm64: 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>
2017-04-07arm64: cpu_errata: Allow an erratum to be match for all revisions of a coreMarc Zyngier
Some minor erratum may not be fixed in further revisions of a core, leading to a situation where the workaround needs to be updated each time an updated core is released. Introduce a MIDR_ALL_VERSIONS match helper that will work for all versions of that MIDR, once and for all. Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-02-10arm64: Work around Falkor erratum 1003Christopher Covington
The Qualcomm Datacenter Technologies Falkor v1 CPU may allocate TLB entries using an incorrect ASID when TTBRx_EL1 is being updated. When the erratum is triggered, page table entries using the new translation table base address (BADDR) will be allocated into the TLB using the old ASID. All circumstances leading to the incorrect ASID being cached in the TLB arise when software writes TTBRx_EL1[ASID] and TTBRx_EL1[BADDR], a memory operation is in the process of performing a translation using the specific TTBRx_EL1 being written, and the memory operation uses a translation table descriptor designated as non-global. EL2 and EL3 code changing the EL1&0 ASID is not subject to this erratum because hardware is prohibited from performing translations from an out-of-context translation regime. Consider the following pseudo code. write new BADDR and ASID values to TTBRx_EL1 Replacing the above sequence with the one below will ensure that no TLB entries with an incorrect ASID are used by software. write reserved value to TTBRx_EL1[ASID] ISB write new value to TTBRx_EL1[BADDR] ISB write new value to TTBRx_EL1[ASID] ISB When the above sequence is used, page table entries using the new BADDR value may still be incorrectly allocated into the TLB using the reserved ASID. Yet this will not reduce functionality, since TLB entries incorrectly tagged with the reserved ASID will never be hit by a later instruction. Based on work by Shanker Donthineni <shankerd@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Christopher Covington <cov@codeaurora.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-02-01arm64: Work around Falkor erratum 1009Christopher Covington
During a TLB invalidate sequence targeting the inner shareable domain, Falkor may prematurely complete the DSB before all loads and stores using the old translation are observed. Instruction fetches are not subject to the conditions of this erratum. If the original code sequence includes multiple TLB invalidate instructions followed by a single DSB, onle one of the TLB instructions needs to be repeated to work around this erratum. While the erratum only applies to cases in which the TLBI specifies the inner-shareable domain (*IS form of TLBI) and the DSB is ISH form or stronger (OSH, SYS), this changes applies the workaround overabundantly-- to local TLBI, DSB NSH sequences as well--for simplicity. Based on work by Shanker Donthineni <shankerd@codeaurora.org> Signed-off-by: Christopher Covington <cov@codeaurora.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-01-13arm64: errata: Provide macro for major and minor cpu revisionsRobert Richter
Definition of cpu ranges are hard to read if the cpu variant is not zero. Provide MIDR_CPU_VAR_REV() macro to describe the full hardware revision of a cpu including variant and (minor) revision. Signed-off-by: Robert Richter <rrichter@cavium.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: 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>
2016-07-27Merge tag 'arm64-upstream' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: - Kexec support for arm64 - Kprobes support - Expose MIDR_EL1 and REVIDR_EL1 CPU identification registers to sysfs - Trapping of user space cache maintenance operations and emulation in the kernel (CPU errata workaround) - Clean-up of the early page tables creation (kernel linear mapping, EFI run-time maps) to avoid splitting larger blocks (e.g. pmds) into smaller ones (e.g. ptes) - VDSO support for CLOCK_MONOTONIC_RAW in clock_gettime() - ARCH_HAS_KCOV enabled for arm64 - Optimise IP checksum helpers - SWIOTLB optimisation to only allocate/initialise the buffer if the available RAM is beyond the 32-bit mask - Properly handle the "nosmp" command line argument - Fix for the initialisation of the CPU debug state during early boot - vdso-offsets.h build dependency workaround - Build fix when RANDOMIZE_BASE is enabled with MODULES off * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (64 commits) arm64: arm: Fix-up the removal of the arm64 regs_query_register_name() prototype arm64: Only select ARM64_MODULE_PLTS if MODULES=y arm64: mm: run pgtable_page_ctor() on non-swapper translation table pages arm64: mm: make create_mapping_late() non-allocating arm64: Honor nosmp kernel command line option arm64: Fix incorrect per-cpu usage for boot CPU arm64: kprobes: Add KASAN instrumentation around stack accesses arm64: kprobes: Cleanup jprobe_return arm64: kprobes: Fix overflow when saving stack arm64: kprobes: WARN if attempting to step with PSTATE.D=1 arm64: debug: remove unused local_dbg_{enable, disable} macros arm64: debug: remove redundant spsr manipulation arm64: debug: unmask PSTATE.D earlier arm64: localise Image objcopy flags arm64: ptrace: remove extra define for CPSR's E bit kprobes: Add arm64 case in kprobe example module arm64: Add kernel return probes support (kretprobes) arm64: Add trampoline code for kretprobes arm64: kprobes instruction simulation support arm64: Treat all entry code as non-kprobe-able ...
2016-07-07arm64: Enable workaround for Cavium erratum 27456 on thunderx-81xxGanapatrao Kulkarni
Cavium erratum 27456 commit 104a0c02e8b1 ("arm64: Add workaround for Cavium erratum 27456") is applicable for thunderx-81xx pass1.0 SoC as well. Adding code to enable to 81xx. Signed-off-by: Ganapatrao Kulkarni <gkulkarni@cavium.com> Reviewed-by: Andrew Pinski <apinski@cavium.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-07-01arm64: trap userspace "dc cvau" cache operation on errata-affected coreAndre Przywara
The ARM errata 819472, 826319, 827319 and 824069 for affected Cortex-A53 cores demand to promote "dc cvau" instructions to "dc civac". Since we allow userspace to also emit those instructions, we should make sure that "dc cvau" gets promoted there too. So lets grasp the nettle here and actually trap every userland cache maintenance instruction once we detect at least one affected core in the system. We then emulate the instruction by executing it on behalf of userland, promoting "dc cvau" to "dc civac" on the way and injecting access fault back into userspace. Signed-off-by: Andre Przywara <andre.przywara@arm.com> [catalin.marinas@arm.com: s/set_segfault/arm64_notify_segfault/] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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: 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>
2016-02-26arm64: 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>
2016-02-16arm64: 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>
2015-11-24arm64: 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: 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>
2015-09-29irqchip/gicv3: Workaround for Cavium ThunderX erratum 23154Robert Richter
This patch implements Cavium ThunderX erratum 23154. The gicv3 of ThunderX requires a modified version for reading the IAR status to ensure data synchronization. Since this is in the fast-path and called with each interrupt, runtime patching is used using jump label patching for smallest overhead (no-op). This is the same technique as used for tracepoints. Signed-off-by: Robert Richter <rrichter@cavium.com> Reviewed-by: Marc Zygnier <marc.zyngier@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Tirumalesh Chalamarla <tchalamarla@cavium.com> Cc: linux-arm-kernel@lists.infradead.org Cc: Jason Cooper <jason@lakedaemon.net> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/1442869119-1814-3-git-send-email-rric@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-04-01arm64: fix midr range for Cortex-A57 erratum 832075Bo Yan
Register MIDR_EL1 is masked to get variant and revision fields, then compared against midr_range_min and midr_range_max when checking whether CPU is affected by any particular erratum. However, variant and revision fields in MIDR_EL1 are separated by 16 bits, so the min and max of midr range should be constructed accordingly, otherwise the patch will not be applied when variant field is non-0. Cc: stable@vger.kernel.org # 3.19+ Acked-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Paul Walmsley <paul@pwsan.com> Signed-off-by: Bo Yan <byan@nvidia.com> [will: use MIDR_VARIANT_SHIFT to construct upper bound] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-04-01arm64: errata: add workaround for cortex-a53 erratum #845719Will Deacon
When running a compat (AArch32) userspace on Cortex-A53, a load at EL0 from a virtual address that matches the bottom 32 bits of the virtual address used by a recent load at (AArch64) EL1 might return incorrect data. This patch works around the issue by writing to the contextidr_el1 register on the exception return path when returning to a 32-bit task. This workaround is patched in at runtime based on the MIDR value of the processor. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-03-30arm64: Extract feature parsing code from cpu_errata.cMarc Zyngier
As we detect more architectural features at runtime, it makes sense to reuse the existing framework whilst avoiding to call a feature an erratum... This patch extract the core capability parsing, moves it into a new file (cpufeature.c), and let the CPU errata detection code use it. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-25arm64: alternatives: fix pr_fmt string for consistencyWill Deacon
Consistently use the plural form for alternatives pr_fmt strings. Signed-off-by: Will Deacon <will.deacon@arm.com>
2014-11-25arm64: protect alternatives workarounds with Kconfig optionsAndre Przywara
Not all of the errata we have workarounds for apply necessarily to all SoCs, so people compiling a kernel for one very specific SoC may not need to patch the kernel. Introduce a new submenu in the "Platform selection" menu to allow people to turn off certain bugs if they are not affected. By default all of them are enabled. Normal users or distribution kernels shouldn't bother to deselect any bugs here, since the alternatives framework will take care of patching them in only if needed. Signed-off-by: Andre Przywara <andre.przywara@arm.com> [will: moved kconfig menu under `Kernel Features'] Signed-off-by: Will Deacon <will.deacon@arm.com>