Changes in mpam_resctrl.c

13f24586a292e35c9cc71e649dc4e4ea1895c5e5 - Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Tue, 21 Apr 2026 01:46:22 +0200

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxPull 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 List of files: /linux/drivers/resctrl/mpam_resctrl.c

818f644ec6cbe00a3cddc767b6316e2f527ae865 - Merge branches 'for-next/misc' and 'for-next/mpam' into for-next/core

Mon, 20 Apr 2026 14:11:50 +0200

Merge branches 'for-next/misc' and 'for-next/mpam' into for-next/core* for-next/misc: : Miscellaneous cleanups/fixes virt: arm-cca-guest: fix error check for RSI_INCOMPLETE arm64/hwcap: Include kernel-hwcap.h in list of generated files* for-next/mpam: : Fix an unmount->remount problem with the CDP emulation, uninitialised : variable and checker warnings 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 List of files: /linux/drivers/resctrl/mpam_resctrl.c

4d5bbbafc170eb21474a37d844211fce6b0f3c51 - arm_mpam: resctrl: Make resctrl_mon_ctx_waiters static

Tue, 14 Apr 2026 15:27:58 +0200

arm_mpam: resctrl: Make resctrl_mon_ctx_waiters staticresctrl_mon_ctx_waiters is not used outside of this file, so make itstatic. 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 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 Reviewed-by: Gavin Shan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

67c0a487efa542cca9477ea84915db2e091f98d0 - arm_mpam: resctrl: Fix the check for no monitor components found

Tue, 14 Apr 2026 15:27:56 +0200

arm_mpam: resctrl: Fix the check for no monitor components foundDan Carpenter reports that, in mpam_resctrl_alloc_domain(), any_mon_comp isused in an 'if' condition when it may be uninitialized. Initialize it toNULL so that the check behaves correctly when no monitor components arefound.Reported-by: Dan Carpenter Fixes: 264c285999fc ("arm_mpam: resctrl: Add monitor initialisation and domain boilerplate")Signed-off-by: Ben Horgan Reviewed-by: Gavin Shan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

f758340da529ccb12531c3f83d5992e912f6c8d5 - arm_mpam: resctrl: Fix MBA CDP alloc_capable handling on unmount

Mon, 13 Apr 2026 11:00:41 +0200

arm_mpam: resctrl: Fix MBA CDP alloc_capable handling on unmountThe code to set MBA's alloc_capable to true appears to be trying torestore alloc_capable on unmount. This can never work becauseresctrl_arch_set_cdp_enabled() is never invoked with RDT_RESOURCE_MBAas 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 tore-enable MBA if the caller opts in to separate control values usingCDP for this resource. This doesn't happen today.Add a comment to describe this.However a bug remains where MBA allocation is permanently disabled afterthe mount with CDP option. Remounting without CDP cannot restore the MBApartition capability.Add a check to re-enable MBA when CDP is disabled, which happens onunmount.Fixes: 6789fb99282c ("arm_mpam: resctrl: Add CDP emulation")Signed-off-by: Zeng Heng [ morse: Added comment for existing code, added hunk to fix this bug from Ben H ]Reviewed-by: James Morse Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

c43267e6794a36013fd495a4d81bf7f748fe4615 - Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Wed, 15 Apr 2026 01:48:56 +0200

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxPull 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() ... List of files: /linux/drivers/resctrl/mpam_resctrl.c

480a9e57cceaf42db6ff874dbfe91de201935035 - Merge branches 'for-next/misc', 'for-next/tlbflush', 'for-next/ttbr-macros-cleanup', 'for-next/kselftest', 'for-next/feat_lsui', 'for-next/mpam', 'for-next/hotplug-batched-tlbi', 'for-next/bbml2-fixes', 'for-next/sysreg', 'for-next/generic-entry' and 'for-next/acpi', remote-tracking branches 'arm64/for-next/perf' and 'arm64/for-next/read-once' into for-next/core

Fri, 10 Apr 2026 15:22:24 +0200

Merge branches 'for-next/misc', 'for-next/tlbflush', 'for-next/ttbr-macros-cleanup', 'for-next/kselftest', 'for-next/feat_lsui', 'for-next/mpam', 'for-next/hotplug-batched-tlbi', 'for-next/bbml2-fixes', 'for-next/sysreg', 'for-next/generic-entry' and 'for-next/acpi', remote-tracking branches 'arm64/for-next/perf' and 'arm64/for-next/read-once' into for-next/core* arm64/for-next/perf: : Perf updates perf/arm-cmn: Fix resource_size_t printk specifier in arm_cmn_init_dtc() perf/arm-cmn: Fix incorrect error check for devm_ioremap() perf: add NVIDIA Tegra410 C2C PMU perf: add NVIDIA Tegra410 CPU Memory Latency PMU perf/arm_cspmu: nvidia: Add Tegra410 PCIE-TGT PMU perf/arm_cspmu: nvidia: Add Tegra410 PCIE PMU perf/arm_cspmu: Add arm_cspmu_acpi_dev_get perf/arm_cspmu: nvidia: Add Tegra410 UCF PMU perf/arm_cspmu: nvidia: Rename doc to Tegra241 perf/arm-cmn: Stop claiming entire iomem region arm64: cpufeature: Use pmuv3_implemented() function arm64: cpufeature: Make PMUVer and PerfMon unsigned KVM: arm64: Read PMUVer as unsigned* arm64/for-next/read-once: : Fixes for __READ_ONCE() with CONFIG_LTO=y arm64, compiler-context-analysis: Permit alias analysis through __READ_ONCE() with CONFIG_LTO=y arm64: Optimize __READ_ONCE() with CONFIG_LTO=y* for-next/misc: : Miscellaneous cleanups/fixes 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/hwcap: Generate the KERNEL_HWCAP_ definitions for the hwcaps arm64: kexec: Remove duplicate allocation for trans_pgd arm64: mm: Use generic enum pgtable_level arm64: scs: Remove redundant save/restore of SCS SP on entry to/from EL0 arm64: remove ARCH_INLINE_** for-next/tlbflush: : Refactor the arm64 TLB invalidation API and implementation arm64: mm: __ptep_set_access_flags must hint correct TTL arm64: mm: Provide level hint for flush_tlb_page() arm64: mm: Wrap flush_tlb_page() around __do_flush_tlb_range() arm64: mm: More flags for __flush_tlb_range() arm64: mm: Refactor __flush_tlb_range() to take flags arm64: mm: Refactor flush_tlb_page() to use __tlbi_level_asid() arm64: mm: Simplify __flush_tlb_range_limit_excess() arm64: mm: Simplify __TLBI_RANGE_NUM() macro arm64: mm: Re-implement the __flush_tlb_range_op macro in C arm64: mm: Inline __TLBI_VADDR_RANGE() into __tlbi_range() arm64: mm: Push __TLBI_VADDR() into __tlbi_level() arm64: mm: Implicitly invalidate user ASID based on TLBI operation arm64: mm: Introduce a C wrapper for by-range TLB invalidation arm64: mm: Re-implement the __tlbi_level macro as a C function* for-next/ttbr-macros-cleanup: : Cleanups of the TTBR1_* macros arm64/mm: Directly use TTBRx_EL1_CnP arm64/mm: Directly use TTBRx_EL1_ASID_MASK arm64/mm: Describe TTBR1_BADDR_4852_OFFSET* for-next/kselftest: : arm64 kselftest updates selftests/arm64: Implement cmpbr_sigill() to hwcap test* for-next/feat_lsui: : Futex support using FEAT_LSUI instructions to avoid toggling PAN arm64: armv8_deprecated: Disable swp emulation when FEAT_LSUI present arm64: Kconfig: Add support for LSUI KVM: arm64: Use CAST instruction for swapping guest descriptor arm64: futex: Support futex with FEAT_LSUI arm64: futex: Refactor futex atomic operation KVM: arm64: kselftest: set_id_regs: Add test for FEAT_LSUI KVM: arm64: Expose FEAT_LSUI to guests arm64: cpufeature: Add FEAT_LSUI* for-next/mpam: (40 commits) : Expose MPAM to user-space via resctrl: : - 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 workaoround for some existing platforms. : - Add documentation for using MPAM and what shape of platforms can use resctrl arm64: mpam: Add initial MPAM documentation arm_mpam: Quirk CMN-650's CSU NRDY behaviour arm_mpam: Add workaround for T241-MPAM-6 arm_mpam: Add workaround for T241-MPAM-4 arm_mpam: Add workaround for T241-MPAM-1 arm_mpam: Add quirk framework arm_mpam: resctrl: Call resctrl_init() on platforms that can support resctrl arm64: mpam: Select ARCH_HAS_CPU_RESCTRL arm_mpam: resctrl: Add empty definitions for assorted resctrl functions arm_mpam: resctrl: Update the rmid reallocation limit arm_mpam: resctrl: Add resctrl_arch_rmid_read() arm_mpam: resctrl: Allow resctrl to allocate monitors arm_mpam: resctrl: Add support for csu counters arm_mpam: resctrl: Add monitor initialisation and domain boilerplate arm_mpam: resctrl: Add kunit test for control format conversions arm_mpam: resctrl: Add support for 'MB' resource arm_mpam: resctrl: Wait for cacheinfo to be ready arm_mpam: resctrl: Add rmid index helpers arm_mpam: resctrl: Convert to/from MPAMs fixed-point formats arm_mpam: resctrl: Hide CDP emulation behind CONFIG_EXPERT ...* for-next/hotplug-batched-tlbi: : arm64/mm: Enable batched TLB flush in unmap_hotplug_range() arm64/mm: Reject memory removal that splits a kernel leaf mapping arm64/mm: Enable batched TLB flush in unmap_hotplug_range()* for-next/bbml2-fixes: : Fixes for realm guest and BBML2_NOABORT arm64: mm: Remove pmd_sect() and pud_sect() arm64: mm: Handle invalid large leaf mappings correctly arm64: mm: Fix rodata=full block mapping support for realm guests* for-next/sysreg: : arm64 sysreg updates 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/sysreg: Update SMIDR_EL1 to DDI0601 2025-06* for-next/generic-entry: : More arm64 refactoring towards using the generic entry code 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() entry: Fix stale comment for irqentry_enter()* for-next/acpi: : arm64 ACPI updates ACPI: AGDI: fix missing newline in error message List of files: /linux/drivers/resctrl/mpam_resctrl.c

fb481ec08699e9daf08ab839a79ab37b1bcca94d - arm_mpam: resctrl: Call resctrl_init() on platforms that can support resctrl

Fri, 13 Mar 2026 15:46:11 +0100

arm_mpam: resctrl: Call resctrl_init() on platforms that can support resctrlNow that MPAM links against resctrl, call resctrl_init() to register thefilesystem and setup resctrl's structures.Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Zeng Heng Tested-by: Punit Agrawal Tested-by: Jesse Chick Reviewed-by: Zeng Heng Reviewed-by: Shaopeng Tan Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Co-developed-by: Ben Horgan Signed-off-by: Ben Horgan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

efc775eadce2c6e0921c21d9c29a7b6686022281 - arm_mpam: resctrl: Add empty definitions for assorted resctrl functions

Fri, 13 Mar 2026 15:46:09 +0100

arm_mpam: resctrl: Add empty definitions for assorted resctrl functionsA few resctrl features and hooks need to be provided, but aren't needed orsupported on MPAM platforms.resctrl has individual hooks to separately enable and disable theclosid/partid and rmid/pmg context switching code. For MPAM this is all thesame thing, as the value in struct task_struct is used to cache the valuethat should be written to hardware. arm64's context switching code isenabled once MPAM is usable, but doesn't touch the hardware unless thevalue has changed.For now event configuration is not supported, and can be turned off byreturning 'false' from resctrl_arch_is_evt_configurable().The new io_alloc feature is not supported either, always return false fromthe enable helper to indicate and fail the enable.Add this, and empty definitions for the other hooks.Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Zeng Heng Tested-by: Punit Agrawal Tested-by: Jesse Chick Reviewed-by: Zeng Heng Reviewed-by: Shaopeng Tan Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Co-developed-by: Ben Horgan Signed-off-by: Ben Horgan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

49b04e401825431529e866470d8d2dcd8e9ef058 - arm_mpam: resctrl: Update the rmid reallocation limit

Fri, 13 Mar 2026 15:46:08 +0100

arm_mpam: resctrl: Update the rmid reallocation limitresctrl's limbo code needs to be told when the data left in a cache issmall enough for the partid+pmg value to be re-allocated.x86 uses the cache size divided by the number of rmid users the cache mayhave. Do the same, but for the smallest cache, and with the number ofpartid-and-pmg users.Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Zeng Heng Tested-by: Punit Agrawal Tested-by: Jesse Chick Reviewed-by: Zeng Heng Reviewed-by: Shaopeng Tan Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Co-developed-by: Ben Horgan Signed-off-by: Ben Horgan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

fb56b29932ca276df268806ad52ed80f40f99a6e - arm_mpam: resctrl: Add resctrl_arch_rmid_read()

Fri, 13 Mar 2026 15:46:07 +0100

arm_mpam: resctrl: Add resctrl_arch_rmid_read()resctrl uses resctrl_arch_rmid_read() to read counters. CDP emulation meansthe counter may need reading in three different ways.The helpers behind the resctrl_arch_ functions will be re-used for the ABMCequivalent functions.Add the rounding helper for checking monitor values while we're here.Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Zeng Heng Tested-by: Jesse Chick Reviewed-by: Shaopeng Tan Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Co-developed-by: Ben Horgan Signed-off-by: Ben Horgan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

2a3c79c61539779a09928893518c8286d7774b54 - arm_mpam: resctrl: Allow resctrl to allocate monitors

Fri, 13 Mar 2026 15:46:06 +0100

arm_mpam: resctrl: Allow resctrl to allocate monitorsWhen resctrl wants to read a domain's 'QOS_L3_OCCUP', it needs to allocatea monitor on the corresponding resource. Monitors are allocated by classinstead of component.Add helpers to allocate a CSU monitor. These helper return an out of rangevalue for MBM counters.Allocating a montitor context is expected to block until hardware resourcesbecome available. This only makes sense for QOS_L3_OCCUP as unallocated MBMcounters are losing data.Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Zeng Heng Tested-by: Punit Agrawal Tested-by: Jesse Chick Reviewed-by: Zeng Heng Reviewed-by: Shaopeng Tan Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Co-developed-by: Ben Horgan Signed-off-by: Ben Horgan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

1458c4f053355f88cc5d190ca02243d2c60fa010 - arm_mpam: resctrl: Add support for csu counters

Fri, 13 Mar 2026 15:46:05 +0100

arm_mpam: resctrl: Add support for csu countersresctrl exposes a counter via a file named llc_occupancy. This isn't reallya counter as its value goes up and down, this is a snapshot of the cachestorage usage monitor.Add some picking code which will only find an L3. The resctrl counterfile is called llc_occupancy but we don't check it is the last one asit is already identified as L3.Tested-by: Shaopeng Tan Tested-by: Zeng Heng Tested-by: Punit Agrawal Tested-by: Gavin Shan Tested-by: Jesse Chick Reviewed-by: Zeng Heng Reviewed-by: Shaopeng Tan Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Co-developed-by: Dave Martin Signed-off-by: Dave Martin Co-developed-by: Ben Horgan Signed-off-by: Ben Horgan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

264c285999fce128fc52743bce582468b26e9f65 - arm_mpam: resctrl: Add monitor initialisation and domain boilerplate

Fri, 13 Mar 2026 15:46:04 +0100

arm_mpam: resctrl: Add monitor initialisation and domain boilerplateAdd the boilerplate that tells resctrl about the mpam monitors that areavailable. resctrl expects all (non-telemetry) monitors to be on the L3 andso advertise them there and invent an L3 resctrl resource if required. TheL3 cache itself has to exist as the cache ids are used as the domainids.Bring the resctrl monitor domains online and offline based on the cpusthey contain.Support for specific monitor types is left to later.Tested-by: Punit Agrawal Reviewed-by: Zeng Heng Reviewed-by: Jonathan Cameron Signed-off-by: Ben Horgan Reviewed-by: Gavin Shan Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Jesse Chick Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

5dc8f73eaa5dfccb229b9a25c797720e6379f8e0 - arm_mpam: resctrl: Add kunit test for control format conversions

Fri, 13 Mar 2026 15:46:03 +0100

arm_mpam: resctrl: Add kunit test for control format conversionsresctrl specifies the format of the control schemes, and these don't matchthe hardware.Some of the conversions are a bit hairy - add some kunit tests.Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Zeng Heng Tested-by: Punit Agrawal Tested-by: Jesse Chick Reviewed-by: Zeng Heng Reviewed-by: Shaopeng Tan Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Signed-off-by: Dave Martin [morse: squashed enough of Dave's fixes in here that it's his patch now!]Signed-off-by: Ben Horgan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

36528c7681b8093f5f9270d2af7c4326d771f181 - arm_mpam: resctrl: Add support for 'MB' resource

Fri, 13 Mar 2026 15:46:02 +0100

arm_mpam: resctrl: Add support for 'MB' resourceresctrl supports 'MB', as a percentage throttling of traffic from theL3. This is the control that mba_sc uses, so ideally the class chosenshould be as close as possible to the counters used for mbm_total. If thereis a single L3, it's the last cache, and the topology of the memory matchesthen the traffic at the memory controller will be equivalent to that ategress of the L3. If these conditions are met allow the memory class toback MB.MB's percentage control should be backed either with the fixed pointfraction MBW_MAX or bandwidth portion bitmaps. The bandwidth portionbitmaps is not used as its tricky to pick which bits to use to avoidcontention, and may be possible to expose this as something other than apercentage in the future.Tested-by: Shaopeng Tan Tested-by: Zeng Heng Tested-by: Punit Agrawal Tested-by: Gavin Shan Tested-by: Jesse Chick Reviewed-by: Zeng Heng Reviewed-by: Shaopeng Tan Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Co-developed-by: Dave Martin Signed-off-by: Dave Martin Co-developed-by: Ben Horgan Signed-off-by: Ben Horgan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

1c1e2968a860c5af9fca67f1c0e88aab83ace0b3 - arm_mpam: resctrl: Wait for cacheinfo to be ready

Fri, 13 Mar 2026 15:46:01 +0100

arm_mpam: resctrl: Wait for cacheinfo to be readyIn order to calculate the rmid realloc threshold the size of the cacheneeds to be known. Cache domains will also be named after the cache id. Sothat this information can be extracted from cacheinfo we need to wait forit to be ready. The cacheinfo information is populated in device_initcall()so we wait for that.Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Zeng Heng Tested-by: Punit Agrawal Tested-by: Jesse Chick Reviewed-by: Zeng Heng Reviewed-by: Shaopeng Tan Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Signed-off-by: Ben Horgan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

3e9b35823aabcb85cc039960256426e50f1fd601 - arm_mpam: resctrl: Add rmid index helpers

Fri, 13 Mar 2026 15:46:00 +0100

arm_mpam: resctrl: Add rmid index helpersBecause MPAM's pmg aren't identical to RDT's rmid, resctrl handles somedata structures by index. This allows x86 to map indexes to RMID, and MPAMto map them to partid-and-pmg.Add the helpers to do this.Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Zeng Heng Tested-by: Punit Agrawal Tested-by: Jesse Chick Reviewed-by: Zeng Heng Reviewed-by: Shaopeng Tan Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Suggested-by: James Morse Signed-off-by: Ben Horgan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

80d147d293130ee3c8a395cbbea1813e26ab9a1b - arm_mpam: resctrl: Convert to/from MPAMs fixed-point formats

Fri, 13 Mar 2026 15:45:59 +0100

arm_mpam: resctrl: Convert to/from MPAMs fixed-point formatsMPAM uses a fixed-point formats for some hardware controls. Resctrlprovides the bandwidth controls as a percentage. Add helpers to convertbetween these.Ensure bwa_wd is at most 16 to make it clear higher values have no meaning.Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Peter Newman Tested-by: Zeng Heng Tested-by: Punit Agrawal Tested-by: Jesse Chick Reviewed-by: Zeng Heng Reviewed-by: Shaopeng Tan Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan Signed-off-by: Dave Martin Signed-off-by: Ben Horgan Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c

01a0021f6c39557037bfc41ede7230a0696677ff - arm_mpam: resctrl: Hide CDP emulation behind CONFIG_EXPERT

Fri, 13 Mar 2026 15:45:58 +0100

arm_mpam: resctrl: Hide CDP emulation behind CONFIG_EXPERTWhen 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 enabledthe mapping is to two different pairs. As the limbo list is reused betweenmounts and CDP disabled on unmount this can lead to stale mapping and thelimbo handler will then make monitor reads with potentially out of rangePARTID. This may then cause an MPAM error interrupt and the driver willdisable MPAM.No problems are expected if you just mount the resctrl file systemonce with CDP enabled and never unmount it. Hide CDP emulation behindCONFIG_EXPERT to protect the unwary.Signed-off-by: Ben Horgan Reviewed-by: Gavin Shan Reviewed-by: Zeng Heng Reviewed-by: James Morse Tested-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Jesse Chick Signed-off-by: James Morse List of files: /linux/drivers/resctrl/mpam_resctrl.c