History log of /linux/arch/arm64/kernel/mpam.c (Results 1 – 6 of 6)
Revision Date Author Comments
# c43267e6 14-Apr-2026 Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'arm64-upstream' of 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

Merge tag 'arm64-upstream' of 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()
...

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# 480a9e57 10-Apr-2026 Catalin Marinas <catalin.marinas@arm.com>

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-fixe

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

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# 37fe0f98 13-Mar-2026 Ben Horgan <ben.horgan@arm.com>

arm64: mpam: Initialise and context switch the MPAMSM_EL1 register

The MPAMSM_EL1 sets the MPAM labels, PMG and PARTID, for loads and stores
generated by a shared SMCU. Disable the traps so the kern

arm64: mpam: Initialise and context switch the MPAMSM_EL1 register

The MPAMSM_EL1 sets the MPAM labels, PMG and PARTID, for loads and stores
generated by a shared SMCU. Disable the traps so the kernel can use it and
set it to the same configuration as the per-EL cpu MPAM configuration.

If an SMCU is not shared with other cpus then it is implementation
defined whether the configuration from MPAMSM_EL1 is used or that from
the appropriate MPAMy_ELx. As we set the same, PMG_D and PARTID_D,
configuration for MPAM0_EL1, MPAM1_EL1 and MPAMSM_EL1 the resulting
configuration is the same regardless.

The range of valid configurations for the PARTID and PMG in MPAMSM_EL1 is
not currently specified in Arm Architectural Reference Manual but the
architect has confirmed that it is intended to be the same as that for the
cpu configuration in the MPAMy_ELx registers.

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>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-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>

show more ...


# 735dad99 13-Mar-2026 James Morse <james.morse@arm.com>

arm64: mpam: Add cpu_pm notifier to restore MPAM sysregs

The MPAM system registers will be lost if the CPU is reset during PSCI's
CPU_SUSPEND.

Add a PM notifier to restore them.

mpam_thread_switch

arm64: mpam: Add cpu_pm notifier to restore MPAM sysregs

The MPAM system registers will be lost if the CPU is reset during PSCI's
CPU_SUSPEND.

Add a PM notifier to restore them.

mpam_thread_switch(current) can't be used as this won't make any changes if
the in-memory copy says the register already has the correct value. In
reality the system register is UNKNOWN out of reset.

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>
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>

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# 831a7f16 13-Mar-2026 James Morse <james.morse@arm.com>

arm64: mpam: Advertise the CPUs MPAM limits to the driver

Requesters need to populate the MPAM fields for any traffic they send on
the interconnect. For the CPUs these values are taken from the
corr

arm64: mpam: Advertise the CPUs MPAM limits to the driver

Requesters need to populate the MPAM fields for any traffic they send on
the interconnect. For the CPUs these values are taken from the
corresponding MPAMy_ELx register. Each requester may have a limit on the
largest PARTID or PMG value that can be used. The MPAM driver has to
determine the system-wide minimum supported PARTID and PMG values.

To do this, the driver needs to be told what each requestor's limit is.

CPUs are special, but this infrastructure is also needed for the SMMU and
GIC ITS. Call the helper to tell the MPAM driver what the CPUs can do.

The return value can be ignored by the arch code as it runs well before the
MPAM driver starts probing.

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: Catalin Marinas <catalin.marinas@arm.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>
[ morse: requestor->requester as argued by ispell ]
Signed-off-by: James Morse <james.morse@arm.com>

show more ...


# 8e06d04f 13-Mar-2026 James Morse <james.morse@arm.com>

arm64: mpam: Context switch the MPAM registers

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
traffi

arm64: mpam: Context switch the MPAM registers

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>

show more ...