aboutsummaryrefslogtreecommitdiff
path: root/drivers/resctrl
AgeCommit message (Collapse)AuthorFilesLines
2026-04-20Merge tag 'arm64-upstream' of ↵Linus Torvalds1-2/+10
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull more arm64 updates from Catalin Marinas: "The main 'feature' is a workaround for C1-Pro erratum 4193714 requiring IPIs during TLB maintenance if a process is running in user space with SME enabled. The hardware acknowledges the DVMSync messages before completing in-flight SME accesses, with security implications. The workaround makes use of the mm_cpumask() to track the cores that need interrupting (arm64 hasn't used this mask before). The rest are fixes for MPAM, CCA and generated header that turned up during the merging window or shortly before. Summary: Core features: - Add workaround for C1-Pro erratum 4193714 - early CME (SME unit) DVMSync acknowledgement. The fix consists of sending IPIs on TLB maintenance to those CPUs running in user space with SME enabled - Include kernel-hwcap.h in list of generated files (missed in a recent commit generating the KERNEL_HWCAP_* macros) CCA: - Fix RSI_INCOMPLETE error check in arm-cca-guest MPAM: - Fix an unmount->remount problem with the CDP emulation, uninitialised variable and checker warnings" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm_mpam: resctrl: Make resctrl_mon_ctx_waiters static arm_mpam: resctrl: Fix the check for no monitor components found arm_mpam: resctrl: Fix MBA CDP alloc_capable handling on unmount virt: arm-cca-guest: fix error check for RSI_INCOMPLETE arm64/hwcap: Include kernel-hwcap.h in list of generated files arm64: errata: Work around early CME DVMSync acknowledgement arm64: cputype: Add C1-Pro definitions arm64: tlb: Pass the corresponding mm to __tlbi_sync_s1ish() arm64: tlb: Introduce __tlbi_sync_s1ish_{kernel,batch}() for TLB maintenance
2026-04-17arm_mpam: resctrl: Make resctrl_mon_ctx_waiters staticBen Horgan1-1/+1
resctrl_mon_ctx_waiters is not used outside of this file, so make it static. This fixes the sparse warning: drivers/resctrl/mpam_resctrl.c:25:1: warning: symbol 'resctrl_mon_ctx_waiters' was not declared. Should it be static? Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202603281842.c2K96tJA-lkp@intel.com/ Fixes: 2a3c79c61539 ("arm_mpam: resctrl: Allow resctrl to allocate monitors") Signed-off-by: Ben Horgan <ben.horgan@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-04-17arm_mpam: resctrl: Fix the check for no monitor components foundBen Horgan1-1/+1
Dan Carpenter reports that, in mpam_resctrl_alloc_domain(), any_mon_comp is used in an 'if' condition when it may be uninitialized. Initialize it to NULL so that the check behaves correctly when no monitor components are found. Reported-by: Dan Carpenter <error27@gmail.com> Fixes: 264c285999fc ("arm_mpam: resctrl: Add monitor initialisation and domain boilerplate") Signed-off-by: Ben Horgan <ben.horgan@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-04-17arm_mpam: resctrl: Fix MBA CDP alloc_capable handling on unmountZeng Heng1-0/+8
The code to set MBA's alloc_capable to true appears to be trying to restore alloc_capable on unmount. This can never work because resctrl_arch_set_cdp_enabled() is never invoked with RDT_RESOURCE_MBA as the rid parameter. Consequently, mpam_resctrl_controls[RDT_RESOURCE_MBA].cdp_enabled always remains false. The alloc_capable setting in resctrl_arch_set_cdp_enabled() is to re-enable MBA if the caller opts in to separate control values using CDP for this resource. This doesn't happen today. Add a comment to describe this. However a bug remains where MBA allocation is permanently disabled after the mount with CDP option. Remounting without CDP cannot restore the MBA partition capability. Add a check to re-enable MBA when CDP is disabled, which happens on unmount. Fixes: 6789fb99282c ("arm_mpam: resctrl: Add CDP emulation") Signed-off-by: Zeng Heng <zengheng4@huawei.com> [ morse: Added comment for existing code, added hunk to fix this bug from Ben H ] Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-04-14Merge tag 'arm64-upstream' of ↵Linus Torvalds6-45/+2395
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 updates from Catalin Marinas: "The biggest changes are MPAM enablement in drivers/resctrl and new PMU support under drivers/perf. On the core side, FEAT_LSUI lets futex atomic operations with EL0 permissions, avoiding PAN toggling. The rest is mostly TLB invalidation refactoring, further generic entry work, sysreg updates and a few fixes. Core features: - Add support for FEAT_LSUI, allowing futex atomic operations without toggling Privileged Access Never (PAN) - Further refactor the arm64 exception handling code towards the generic entry infrastructure - Optimise __READ_ONCE() with CONFIG_LTO=y and allow alias analysis through it Memory management: - Refactor the arm64 TLB invalidation API and implementation for better control over barrier placement and level-hinted invalidation - Enable batched TLB flushes during memory hot-unplug - Fix rodata=full block mapping support for realm guests (when BBML2_NOABORT is available) Perf and PMU: - Add support for a whole bunch of system PMUs featured in NVIDIA's Tegra410 SoC (cspmu extensions for the fabric and PCIe, new drivers for CPU/C2C memory latency PMUs) - Clean up iomem resource handling in the Arm CMN driver - Fix signedness handling of AA64DFR0.{PMUVer,PerfMon} MPAM (Memory Partitioning And Monitoring): - Add architecture context-switch and hiding of the feature from KVM - Add interface to allow MPAM to be exposed to user-space using resctrl - Add errata workaround for some existing platforms - Add documentation for using MPAM and what shape of platforms can use resctrl Miscellaneous: - Check DAIF (and PMR, where relevant) at task-switch time - Skip TFSR_EL1 checks and barriers in synchronous MTE tag check mode (only relevant to asynchronous or asymmetric tag check modes) - Remove a duplicate allocation in the kexec code - Remove redundant save/restore of SCS SP on entry to/from EL0 - Generate the KERNEL_HWCAP_ definitions from the arm64 hwcap descriptions - Add kselftest coverage for cmpbr_sigill() - Update sysreg definitions" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (109 commits) arm64: rsi: use linear-map alias for realm config buffer arm64: Kconfig: fix duplicate word in CMDLINE help text arm64: mte: Skip TFSR_EL1 checks and barriers in synchronous tag check mode arm64/sysreg: Update ID_AA64SMFR0_EL1 description to DDI0601 2025-12 arm64/sysreg: Update ID_AA64ZFR0_EL1 description to DDI0601 2025-12 arm64/sysreg: Update ID_AA64FPFR0_EL1 description to DDI0601 2025-12 arm64/sysreg: Update ID_AA64ISAR2_EL1 description to DDI0601 2025-12 arm64/sysreg: Update ID_AA64ISAR0_EL1 description to DDI0601 2025-12 arm64/hwcap: Generate the KERNEL_HWCAP_ definitions for the hwcaps arm64: kexec: Remove duplicate allocation for trans_pgd ACPI: AGDI: fix missing newline in error message arm64: Check DAIF (and PMR) at task-switch time arm64: entry: Use split preemption logic arm64: entry: Use irqentry_{enter_from,exit_to}_kernel_mode() arm64: entry: Consistently prefix arm64-specific wrappers arm64: entry: Don't preempt with SError or Debug masked entry: Split preemption from irqentry_exit_to_kernel_mode() entry: Split kernel mode logic from irqentry_{enter,exit}() entry: Move irqentry_enter() prototype later entry: Remove local_irq_{enable,disable}_exit_to_user() ...
2026-03-27arm_mpam: Quirk CMN-650's CSU NRDY behaviourJames Morse2-0/+18
CMN-650 is afflicted with an erratum where the CSU NRDY bit never clears. This tells us the monitor never finishes scanning the cache. The erratum document says to wait the maximum time, then ignore the field. Add a flag to indicate whether this is the final attempt to read the counter, and when this quirk is applied, ignore the NRDY field. This means accesses to this counter will always retry, even if the counter was previously programmed to the same values. The counter value is not expected to be stable, it drifts up and down with each allocation and eviction. The CSU register provides the value for a point in time. Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: Add workaround for T241-MPAM-6Shanker Donthineni2-2/+25
The registers MSMON_MBWU_L and MSMON_MBWU return the number of requests rather than the number of bytes transferred. Bandwidth resource monitoring is performed at the last level cache, where each request arrive in 64Byte granularity. The current implementation returns the number of transactions received at the last level cache but does not provide the value in bytes. Scaling by 64 gives an accurate byte count to match the MPAM specification for the MSMON_MBWU and MSMON_MBWU_L registers. This patch fixes the issue by reporting the actual number of bytes instead of the number of transactions from __ris_msmon_read(). Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: Add workaround for T241-MPAM-4Shanker Donthineni2-3/+53
In the T241 implementation of memory-bandwidth partitioning, in the absence of contention for bandwidth, the minimum bandwidth setting can affect the amount of achieved bandwidth. Specifically, the achieved bandwidth in the absence of contention can settle to any value between the values of MPAMCFG_MBW_MIN and MPAMCFG_MBW_MAX. Also, if MPAMCFG_MBW_MIN is set zero (below 0.78125%), once a core enters a throttled state, it will never leave that state. The first issue is not a concern if the MPAM software allows to program MPAMCFG_MBW_MIN through the sysfs interface. This patch ensures program MBW_MIN=1 (0.78125%) whenever MPAMCFG_MBW_MIN=0 is programmed. In the scenario where the resctrl doesn't support the MBW_MIN interface via sysfs, to achieve bandwidth closer to MBW_MAX in the absence of contention, software should configure a relatively narrow gap between MBW_MIN and MBW_MAX. The recommendation is to use a 5% gap to mitigate the problem. Clear the feature MBW_MIN feature from the class to ensure we don't accidentally change behaviour when resctrl adds support for a MBW_MIN interface. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghuay@nvidia.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: Add workaround for T241-MPAM-1Shanker Donthineni2-0/+97
The MPAM bandwidth partitioning controls will not be correctly configured, and hardware will retain default configuration register values, meaning generally that bandwidth will remain unprovisioned. To address the issue, follow the below steps after updating the MBW_MIN and/or MBW_MAX registers. - Perform 64b reads from all 12 bridge MPAM shadow registers at offsets (0x360048 + slice*0x10000 + partid*8). These registers are read-only. - Continue iterating until all 12 shadow register values match in a loop. pr_warn_once if the values fail to match within the loop count 1000. - Perform 64b writes with the value 0x0 to the two spare registers at offsets 0x1b0000 and 0x1c0000. In the hardware, writes to the MPAMCFG_MBW_MAX MPAMCFG_MBW_MIN registers are transformed into broadcast writes to the 12 shadow registers. The final two writes to the spare registers cause a final rank of downstream micro-architectural MPAM registers to be updated from the shadow copies. The intervening loop to read the 12 shadow registers helps avoid a race condition where writes to the spare registers occur before all shadow registers have been updated. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: Add quirk frameworkShanker Donthineni2-0/+57
The MPAM specification includes the MPAMF_IIDR, which serves to uniquely identify the MSC implementation through a combination of implementer details, product ID, variant, and revision. Certain hardware issues/errata can be resolved using software workarounds. Introduce a quirk framework to allow workarounds to be enabled based on the MPAMF_IIDR value. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Co-developed-by: James Morse <james.morse@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Call resctrl_init() on platforms that can support resctrlJames Morse3-5/+94
Now that MPAM links against resctrl, call resctrl_init() to register the filesystem and setup resctrl's structures. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm64: mpam: Select ARCH_HAS_CPU_RESCTRLJames Morse2-1/+8
Enough MPAM support is present to enable ARCH_HAS_CPU_RESCTRL. Let it rip^Wlink! ARCH_HAS_CPU_RESCTRL indicates resctrl can be enabled. It is enabled by the arch code simply because it has 'arch' in its name. This removes ARM_CPU_RESCTRL as a mimic of X86_CPU_RESCTRL. While here, move the ACPI dependency to the driver's Kconfig file. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Add empty definitions for assorted resctrl functionsJames Morse1-0/+65
A few resctrl features and hooks need to be provided, but aren't needed or supported on MPAM platforms. resctrl has individual hooks to separately enable and disable the closid/partid and rmid/pmg context switching code. For MPAM this is all the same thing, as the value in struct task_struct is used to cache the value that should be written to hardware. arm64's context switching code is enabled once MPAM is usable, but doesn't touch the hardware unless the value has changed. For now event configuration is not supported, and can be turned off by returning 'false' from resctrl_arch_is_evt_configurable(). The new io_alloc feature is not supported either, always return false from the enable helper to indicate and fail the enable. Add this, and empty definitions for the other hooks. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Update the rmid reallocation limitJames Morse1-0/+39
resctrl's limbo code needs to be told when the data left in a cache is small enough for the partid+pmg value to be re-allocated. x86 uses the cache size divided by the number of rmid users the cache may have. Do the same, but for the smallest cache, and with the number of partid-and-pmg users. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Add resctrl_arch_rmid_read()James Morse1-0/+82
resctrl uses resctrl_arch_rmid_read() to read counters. CDP emulation means the counter may need reading in three different ways. The helpers behind the resctrl_arch_ functions will be re-used for the ABMC equivalent functions. Add the rounding helper for checking monitor values while we're here. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Allow resctrl to allocate monitorsJames Morse2-1/+80
When resctrl wants to read a domain's 'QOS_L3_OCCUP', it needs to allocate a monitor on the corresponding resource. Monitors are allocated by class instead of component. Add helpers to allocate a CSU monitor. These helper return an out of range value for MBM counters. Allocating a montitor context is expected to block until hardware resources become available. This only makes sense for QOS_L3_OCCUP as unallocated MBM counters are losing data. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Add support for csu countersJames Morse1-0/+83
resctrl exposes a counter via a file named llc_occupancy. This isn't really a counter as its value goes up and down, this is a snapshot of the cache storage usage monitor. Add some picking code which will only find an L3. The resctrl counter file is called llc_occupancy but we don't check it is the last one as it is already identified as L3. Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Dave Martin <dave.martin@arm.com> Signed-off-by: Dave Martin <dave.martin@arm.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Add monitor initialisation and domain boilerplateBen Horgan2-11/+235
Add the boilerplate that tells resctrl about the mpam monitors that are available. resctrl expects all (non-telemetry) monitors to be on the L3 and so advertise them there and invent an L3 resctrl resource if required. The L3 cache itself has to exist as the cache ids are used as the domain ids. Bring the resctrl monitor domains online and offline based on the cpus they contain. Support for specific monitor types is left to later. Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Add kunit test for control format conversionsDave Martin2-0/+319
resctrl specifies the format of the control schemes, and these don't match the hardware. Some of the conversions are a bit hairy - add some kunit tests. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> [morse: squashed enough of Dave's fixes in here that it's his patch now!] Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Add support for 'MB' resourceJames Morse1-1/+280
resctrl supports 'MB', as a percentage throttling of traffic from the L3. This is the control that mba_sc uses, so ideally the class chosen should be as close as possible to the counters used for mbm_total. If there is a single L3, it's the last cache, and the topology of the memory matches then the traffic at the memory controller will be equivalent to that at egress of the L3. If these conditions are met allow the memory class to back MB. MB's percentage control should be backed either with the fixed point fraction MBW_MAX or bandwidth portion bitmaps. The bandwidth portion bitmaps is not used as its tricky to pick which bits to use to avoid contention, and may be possible to expose this as something other than a percentage in the future. Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Wait for cacheinfo to be readyBen Horgan1-0/+19
In order to calculate the rmid realloc threshold the size of the cache needs to be known. Cache domains will also be named after the cache id. So that this information can be extracted from cacheinfo we need to wait for it to be ready. The cacheinfo information is populated in device_initcall() so we wait for that. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Add rmid index helpersBen Horgan1-0/+16
Because MPAM's pmg aren't identical to RDT's rmid, resctrl handles some data structures by index. This allows x86 to map indexes to RMID, and MPAM to map them to partid-and-pmg. Add the helpers to do this. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Suggested-by: James Morse <james.morse@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Convert to/from MPAMs fixed-point formatsDave Martin2-0/+58
MPAM uses a fixed-point formats for some hardware controls. Resctrl provides the bandwidth controls as a percentage. Add helpers to convert between these. Ensure bwa_wd is at most 16 to make it clear higher values have no meaning. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Dave Martin <Dave.Martin@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Hide CDP emulation behind CONFIG_EXPERTBen Horgan1-0/+12
When CDP is not enabled, the 'rmid_entry's in the limbo list, rmid_busy_llc, map directly to a (PARTID,PMG) pair and when CDP is enabled the mapping is to two different pairs. As the limbo list is reused between mounts and CDP disabled on unmount this can lead to stale mapping and the limbo handler will then make monitor reads with potentially out of range PARTID. This may then cause an MPAM error interrupt and the driver will disable MPAM. No problems are expected if you just mount the resctrl file system once with CDP enabled and never unmount it. Hide CDP emulation behind CONFIG_EXPERT to protect the unwary. Signed-off-by: Ben Horgan <ben.horgan@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: James Morse <james.morse@arm.com> Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Add CDP emulationJames Morse2-0/+123
Intel RDT's CDP feature allows the cache to use a different control value depending on whether the accesses was for instruction fetch or a data access. MPAM's equivalent feature is the other way up: the CPU assigns a different partid label to traffic depending on whether it was instruction fetch or a data access, which causes the cache to use a different control value based solely on the partid. MPAM can emulate CDP, with the side effect that the alternative partid is seen by all MSC, it can't be enabled per-MSC. Add the resctrl hooks to turn this on or off. Add the helpers that match a closid against a task, which need to be aware that the value written to hardware is not the same as the one resctrl is using. Update the 'arm64_mpam_global_default' variable the arch code uses during context switch to know when the per-cpu value should be used instead. Also, update these per-cpu values and sync the resulting mpam partid/pmg configuration to hardware. resctrl can enable CDP for L2 caches, L3 caches or both. When it is enabled by one and not the other MPAM globally enabled CDP but hides the effect on the other cache resource. This hiding is possible as CPOR is the only supported cache control and that uses a resource bitmap; two partids with the same bitmap act as one. Awkwardly, the MB controls don't implement CDP and CDP can't be hidden as the memory bandwidth control is a maximum per partid which can't be modelled with more partids. If the total maximum is used for both the data and instruction partids then then the maximum may be exceeded and if it is split in two then the one using more bandwidth will hit a lower limit. Hence, hide the MB controls completely if CDP is enabled for any resource. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: Amit Singh Tomar <amitsinght@marvell.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Add plumbing against arm64 task and cpu hooksJames Morse1-0/+58
arm64 provides helpers for changing a task's and a cpu's mpam partid/pmg values. These are used to back a number of resctrl_arch_ functions. Connect them up. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Implement helpers to update configurationJames Morse1-0/+70
resctrl has two helpers for updating the configuration. resctrl_arch_update_one() updates a single value, and is used by the software-controller to apply feedback to the bandwidth controls, it has to be called on one of the CPUs in the resctrl:domain. resctrl_arch_update_domains() copies multiple staged configurations, it can be called from anywhere. Both helpers should update any changes to the underlying hardware. Implement resctrl_arch_update_domains() to use resctrl_arch_update_one(). Neither need to be called on a specific CPU as the mpam driver will send IPIs as needed. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Add resctrl_arch_get_config()James Morse1-0/+43
Implement resctrl_arch_get_config() by testing the live configuration for a CPOR bitmap. For any other configuration type return the default. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Implement resctrl_arch_reset_all_ctrls()James Morse3-1/+17
We already have a helper for resetting an mpam class and component. Hook it up to resctrl_arch_reset_all_ctrls() and the domain offline path. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Pick the caches we will use as resctrl resourcesJames Morse1-2/+89
Systems with MPAM support may have a variety of control types at any point of their system layout. We can only expose certain types of control, and only if they exist at particular locations. Start with the well-known caches. These have to be depth 2 or 3 and support MPAM's cache portion bitmap controls, with a number of portions fewer than resctrl's limit. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: resctrl: Add boilerplate cpuhp and domain allocationJames Morse4-0/+358
resctrl has its own data structures to describe its resources. We can't use these directly as we play tricks with the 'MBA' resource, picking the MPAM controls or monitors that best apply. We may export the same component as both L3 and MBA. Add mpam_resctrl_res[] as the array of class->resctrl mappings we are exporting, and add the cpuhp hooks that allocated and free the resctrl domain structures. Only the mpam control feature are considered here and monitor support will be added later. While we're here, plumb in a few other obvious things. CONFIG_ARM_CPU_RESCTRL is used to allow this code to be built even though it can't yet be linked against resctrl. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm64: mpam: Drop the CONFIG_EXPERT restrictionBen Horgan1-1/+1
In anticipation of MPAM being useful remove the CONFIG_EXPERT restriction. This was done to prevent the driver being enabled before the user-space interface was wired up. Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: James Morse <james.morse@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> [ morse: Added second paragraph ] Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm64: mpam: Context switch the MPAM registersJames Morse2-4/+2
MPAM allows traffic in the SoC to be labeled by the OS, these labels are used to apply policy in caches and bandwidth regulators, and to monitor traffic in the SoC. The label is made up of a PARTID and PMG value. The x86 equivalent calls these CLOSID and RMID, but they don't map precisely. MPAM has two CPU system registers that is used to hold the PARTID and PMG values that traffic generated at each exception level will use. These can be set per-task by the resctrl file system. (resctrl is the defacto interface for controlling this stuff). Add a helper to switch this. struct task_struct's separate CLOSID and RMID fields are insufficient to implement resctrl using MPAM, as resctrl can change the PARTID (CLOSID) and PMG (sort of like the RMID) separately. On x86, the rmid is an independent number, so a race that writes a mismatched closid and rmid into hardware is benign. On arm64, the pmg bits extend the partid. (i.e. partid-5 has a pmg-0 that is not the same as partid-6's pmg-0). In this case, mismatching the values will 'dirty' a pmg value that resctrl believes is clean, and is not tracking with its 'limbo' code. To avoid this, the partid and pmg are always read and written as a pair. This requires a new u64 field. In struct task_struct there are two u32, rmid and closid for the x86 case, but as we can't use them here do something else. Add this new field, mpam_partid_pmg, to struct thread_info to avoid adding more architecture specific code to struct task_struct. Always use READ_ONCE()/WRITE_ONCE() when accessing this field. Resctrl allows a per-cpu 'default' value to be set, this overrides the values when scheduling a task in the default control-group, which has PARTID 0. The way 'code data prioritisation' gets emulated means the register value for the default group needs to be a variable. The current system register value is kept in a per-cpu variable to avoid writing to the system register if the value isn't going to change. Writes to this register may reset the hardware state for regulating bandwidth. Finally, there is no reason to context switch these registers unless there is a driver changing the values in struct task_struct. Hide the whole thing behind a static key. This also allows the driver to disable MPAM in response to errors reported by hardware. Move the existing static key to belong to the arch code, as in the future the MPAM driver may become a loadable module. All this should depend on whether there is an MPAM driver, hide it behind CONFIG_ARM64_MPAM. Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Zeng Heng <zengheng4@huawei.com> Tested-by: Punit Agrawal <punit.agrawal@oss.qualcomm.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> CC: Amit Singh Tomar <amitsinght@marvell.com> Reviewed-by: Zeng Heng <zengheng4@huawei.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Co-developed-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: Ben Horgan <ben.horgan@arm.com> Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: Reset when feature configuration bit unsetBen Horgan2-32/+12
To indicate that the configuration, of the controls used by resctrl, in a RIS need resetting to driver defaults the reset flags in mpam_config are set. However, these flags are only ever set temporarily at RIS scope in mpam_reset_ris() and hence mpam_cpu_online() will never reset these controls to default. As the hardware reset is unknown this leads to unknown configuration when the control values haven't been configured away from the defaults. Use the policy that an unset feature configuration bit means reset. In this way the mpam_config in the component can encode that it should be in reset state and mpam_reprogram_msc() will reset controls as needed. Fixes: 09b89d2a72f3 ("arm_mpam: Allow configuration to be applied and restored during cpu online") Signed-off-by: Ben Horgan <ben.horgan@arm.com> Reviewed-by: Gavin Shan <gshan@redhat.com> Reviewed-by: James Morse <james.morse@arm.com> Tested-by: Gavin Shan <gshan@redhat.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Tested-by: Jesse Chick <jessechick@os.amperecomputing.com> [ morse: Removed unused reset flags from config structure ] Signed-off-by: James Morse <james.morse@arm.com>
2026-03-27arm_mpam: Ensure in_reset_state is false after applying configurationZeng Heng1-0/+1
The per-RIS flag, in_reset_state, indicates whether or not the MSC registers are in reset state, and allows avoiding resetting when they are already in reset state. However, when mpam_apply_config() updates the configuration it doesn't update the in_reset_state flag and so even after the configuration update in_reset_state can be true and mpam_reset_ris() will skip the actual register restoration on subsequent resets. Once resctrl has a MPAM backend it will use resctrl_arch_reset_all_ctrls() to reset the MSC configuration on unmount and, if the in_reset_state flag is bogusly true, fail to reset the MSC configuration. The resulting non-reset MSC configuration can lead to persistent performance restrictions even after resctrl is unmounted. Fix by clearing in_reset_state to false immediately after successful configuration application, ensuring that the next reset operation properly restores MSC register defaults. Fixes: 09b89d2a72f3 ("arm_mpam: Allow configuration to be applied and restored during cpu online") Signed-off-by: Zeng Heng <zengheng4@huawei.com> Acked-by: Ben Horgan <ben.horgan@arm.com> [Horgan: rewrite commit message to not be specific to resctrl unmount] Signed-off-b