linux.git/drivers/resctrl, branch master

arm_mpam: guard MBWU state before adding it to garbage

2026-07-16T13:46:27Z

__destroy_component_cfg() adds each RIS mbwu_state object to the MPAM garbage list when destroying component configuration. However, mbwu_state is allocated per RIS and only for RISes with MBWU monitors. A component can therefore have comp->cfg allocated while some RISes still have ris->mbwu_state set to NULL. Passing a NULL mbwu_state to add_to_garbage() dereferences the NULL pointer inside the macro. Skip RISes that do not have an mbwu_state object before adding them to the garbage list. Fixes: 41e8a14950e1 ("arm_mpam: Track bandwidth counter state for power management") Signed-off-by: Guangshuo Li Reviewed-by: Ben Horgan Signed-off-by: Will Deacon

arm_mpam: Fix MPAMCFG_MBW_PBM register setting

2026-07-16T13:45:47Z

MPAMCFG_MBW_PBM is written from cfg if cfg has the MBW partition feature. It is reset when cfg does not have the MBW partition feature. But the register handling is reversed. This may cause an incorrect register setting. For example, during an MPAM reset, reset_cfg is empty (no MBW partition feature set), and cfg->mbw_pbm is 0. Instead of resetting MPAMCFG_MBW_PBM to all 1's, the current logic will set it to cfg->mbw_pbm, which is 0. Fix the issue by swapping the if/else branches. Fixes: a1cb6577f575 ("arm_mpam: Reset when feature configuration bit unset") Reported-by: Matt Ochs Signed-off-by: Fenghua Yu Reviewed-by: Gavin Shan Reviewed-by: Ben Horgan Signed-off-by: Will Deacon

arm_mpam: Fix software reset values of MPAMCFG_PRI

2026-07-16T13:44:12Z

Priority partitioning is not supported other than to set the per-PARTID defaults in MPAMCFG_PRI, INTPRI and DSPRI, to the highest priority. When 0 is the lowest priority, all ones is the highest priority. However, these values are calculated with an extra higher bit set. Luckily, there is still no chance of setting functional bits incorrectly. When the priority widths are maximal, this is ensured as the fields have width 16 and a u16 holds the value for each field. When the widths are smaller, the higher order bits beyond the advertised widths, MPAMF_PRI_IDR.DSPRI_WD and MPAMF_PRI_IDR.INTPRI_WD, in the priority fields INTPRI and DSPRI are not used to calculate the priority. It is not specified whether these higher order bits are RAZ/WI or Res0 and so it is desirable not to set them to avoid the chance of misleading reads. Correct the priority reset values. Fixes: 880df85d8673 ("arm_mpam: Probe and reset the rest of the features") Signed-off-by: Ben Horgan Signed-off-by: Will Deacon

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

2026-06-15T23:48:04Z

Pull arm64 updates from Will Deacon: "It feels like the new world of AI tooling has slowed us down a little on the feature side when compared to the fixes side. The extra rounds of Sashiko review have also pushed a few things out until next time. Still, there's some good foundational stuff here for the fpsimd code and hardening work towards removing the predictable linear alias of the kernel image. CPU errata handling: - Extend CnP disabling workaround to HiSilicon HIP09 hardware. - Work around eternally broken broadcast TLB invalidation on more CPUs. - Documentation and code cleanups. CPU features: - Add new hwcaps for the 2025 dpISA extensions. Floating point / SVE / SME: - Significant cleanup to the low-level state management code in the core architecture code and KVM. - Use correct register widths during SVE/SME save/restore assembly. - Expose SVE/SME save/restore memory accesses to sanitisers. Memory management: - Preparatory work for unmapping the kernel data and bss sections from the linear map. Miscellaneous: - Inline DAIF manipulation helpers so they can be used safely from non-instrumentable code. - Fix handling of the 'nosmp' cmdline option to avoid marking secondary cores as "possible". MPAM: - Add support for v0.1 of the MPAM architecture. Perf: - Update HiSilicon PMU MAINTAINERS entry. - Fix event encodings for the DVM node in the CMN driver. Selftests: - Extend sigframe tests to cover POE context. - Add coverage for the newly added 2025 dpISA hwcaps. System registers: - Add new registers and ESR encodings for the HDBSS feature. Plus minor fixes and cleanups across the board" * tag 'arm64-upstream' of gitolite.kernel.org:pub/scm/linux/kernel/git/arm64/linux: (73 commits) arm64: errata: Mitigate TLBI errata on Microsoft Azure Cobalt 100 CPU arm64: errata: Mitigate TLBI errata on NVIDIA Olympus CPU arm64: errata: Mitigate TLBI errata on various Arm CPUs arm64: cputype: Add C1-Premium definitions arm64: cputype: Add C1-Ultra definitions Revert "arm64: mm: Unmap kernel data/bss entirely from the linear map" Revert "arm64: mm: Defer remap of linear alias of data/bss" arm64: arch_timer: reuse arch_timer_read_cnt{p,v}ct_el0() helpers arm64/mm: Rename ptdesc_t arm64: mm: Defer remap of linear alias of data/bss KVM: arm64: Omit tag sync on stage-2 mappings of the zero page arm64: Avoid double evaluation of __ptep_get() kasan: Move generic KASAN page tables out of BSS too arm64: Rename page table BSS section to .bss..pgtbl arm64: patching: replace min_t with min in __text_poke perf/arm-cmn: Fix DVM node events arm64: fpsimd: Remove arm64: fpsimd: Move SME save/restore inline arm64: fpsimd: Move sve_flush_live() inline arm64: fpsimd: Move SVE save/restore inline ...

arm_mpam: Update architecture version check for MPAM MSC

2026-05-19T12:04:28Z

In addition to updating the CPU MPAM version check, the MPAM MSC version check also need to be updated. mpam_msc_check_aidr() is added to check the MSC AIDR register, ensuring that both the major and minor version numbers fall within the supported range of the MPAM architecture version. Signed-off-by: Zeng Heng [ morse: changed mpam_msc_check_aidr() to accept versions like v1.2 ] Signed-off-by: James Morse Reviewed-by: Ben Horgan Signed-off-by: Will Deacon

arm_mpam: Check whether the config array is allocated before destroying it

2026-05-14T08:52:05Z

__destroy_component_cfg() is called to free the configuration array. It uses the embedded 'garbage' structure, which means the array has to be allocated. If __destroy_component_cfg() is called from mpam_disable() before the configuration was ever allocated, then a NULL pointer is dereferenced. Check for this case and return early if the configuration is not allocated. __destroy_component_cfg() also frees the mbwu_state as this is allocated by __allocate_component_cfg(). As the mbwu_state is allocated after comp->cfg is set, and is also under mpam_list_lock, only the first pointer needs checking. Fixes: 3bd04fe7d807 ("arm_mpam: Extend reset logic to allow devices to be reset any time") Cc: Signed-off-by: James Morse Reviewed-by: Ben Horgan Signed-off-by: Catalin Marinas

arm_mpam: Fix false positive assert failure during mpam_disable()

2026-05-14T08:52:00Z

mpam_assert_partid_sizes_fixed() is used to document that the caller doesn't expect the discovered PARTID size to change while it is walking a list sized by PARTID. Typically the MSC state is not written to until all the MSC have been discovered and this value is set. However, if discovering the MSC fails and schedules mpam_disable(), then the MSC state is written to reset it. In this case the discovered PARTID size may be become smaller - but only PARTID 0 will be used once resctrl_exit() has been called. Skip the WARN_ON_ONCE() if mpam_disable_reason has been set. Fixes: 3bd04fe7d807 ("arm_mpam: Extend reset logic to allow devices to be reset any time") Cc: Signed-off-by: James Morse Reviewed-by: Ben Horgan Signed-off-by: Catalin Marinas

arm_mpam: Improve check for whether or not NRDY is hardware managed

2026-05-14T08:51:55Z

mpam_ris_hw_probe_csu_nrdy() sets and clears MSMON_CSU.NRDY and checks whether it's configuration sticks. However, hardware isn't given a chance to disagree. Based on rule LRTGP, in MPAM specification IHI0099 version B.b, the hardware will set NRDY if it needs time to establish a count after a configuration change. Enable the monitor so that NRDY becomes relevant and change the configuration after clearing NRDY to try and coax the hardware into setting it. Fixes: 8c90dc68a5de ("arm_mpam: Probe the hardware features resctrl supports") Cc: Signed-off-by: Ben Horgan Reviewed-by: James Morse Signed-off-by: Catalin Marinas

arm_mpam: Pretend that NRDY is always hardware managed

2026-05-14T08:51:50Z

Rule ZTXDS of the MPAM specification, IHI009 version B.b, states: "If a monitor does not support automatic updates of NRDY, software can use that bit for any purpose." As software is not reliably informed whether or not the monitor supports automatic updates of NRDY always assume that hardware may manage NRDY but don't rely on it. When NRDY is truly untouched by hardware then, as it is written to 0 on configuration, it will always read 0. At probe it's checked if MSMON_CSU.NRDY and MSMON_MBWU.NRDY are hardware managed but not MSMON_MBWU_L.NDRY. Specialize the checking for hardware managed NRDY to CSU counters as this is the only case where hardware management makes sense. Continue to inform the user if MSMON_CSU.NRDY appears to be hardware managed but the firmware doesn't provide the associated time limit for the automatic clearing of NRDY. Remove the NRDY feature flags as they are now unused. Fixes: 8c90dc68a5de ("arm_mpam: Probe the hardware features resctrl supports") Cc: Signed-off-by: Ben Horgan Reviewed-by: James Morse Signed-off-by: Catalin Marinas

arm_mpam: Fix monitor instance selection when checking for hardware NRDY

2026-05-14T08:51:41Z

In _mpam_ris_hw_probe_hw_nrdy() a new register value to select the first monitor and relevant RIS is prepared in mon_sel. However, it is written to the monitor value register, e.g. MSMON_CSU, rather than MSMON_CFG_MON_SEL. As MSMON_CFG_MON_SEL is a 32 bit register update the type of mon_sel to u32. Write mon_sel to the intended register, MSMON_CFG_MON_SEL. Fixes: 8c90dc68a5de ("arm_mpam: Probe the hardware features resctrl supports") Cc: Signed-off-by: Ben Horgan Reviewed-by: James Morse Signed-off-by: Catalin Marinas