Commit Graph

1427986 Commits

Author SHA1 Message Date
Catalin Marinas
818f644ec6 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
2026-04-20 13:11:50 +01:00
Ben Horgan
4d5bbbafc1 arm_mpam: resctrl: Make resctrl_mon_ctx_waiters static
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: 2a3c79c615 ("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>
2026-04-17 17:48:07 +01:00
Ben Horgan
67c0a487ef arm_mpam: resctrl: Fix the check for no monitor components found
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: 264c285999 ("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>
2026-04-17 17:48:07 +01:00
Zeng Heng
f758340da5 arm_mpam: resctrl: Fix MBA CDP alloc_capable handling on unmount
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: 6789fb9928 ("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>
2026-04-17 17:43:57 +01:00
Sami Mujawar
e534e9d13d virt: arm-cca-guest: fix error check for RSI_INCOMPLETE
The RSI interface can return RSI_INCOMPLETE when a report spans
multiple granules. This is an expected condition and should not be
treated as a fatal error.

Currently, arm_cca_report_new() checks for `info.result != RSI_SUCCESS`
and bails out, which incorrectly flags RSI_INCOMPLETE as a failure.
Fix the check to only break out on results other than RSI_SUCCESS or
RSI_INCOMPLETE.

This ensures partial reports are handled correctly and avoids spurious
-ENXIO errors when generating attestation reports.

Fixes: 7999edc484 ("virt: arm-cca-guest: TSM_REPORT support for realms")
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reported-by: Jagdish Gediya <Jagdish.Gediya@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-14 16:26:08 +01:00
Mark Brown
680b961ebf arm64/hwcap: Include kernel-hwcap.h in list of generated files
When adding generation for the kernel internal constants for hwcaps the
generated file was not explicitly flagged as such in the build system,
causing it to be regenerated on each build. This wasn't obvious when the
series the change was included in was developed since it was all about
changes that trigger rebuilds anyway.

Fixes: abed23c3c4 ("arm64/hwcap: Generate the KERNEL_HWCAP_ definitions for the hwcaps")
Reported-by: Marek Vasut <marex@nabladev.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-14 16:23:40 +01:00
Catalin Marinas
480a9e57cc 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
2026-04-10 14:22:24 +01:00
Aneesh Kumar K.V (Arm)
34e563947c arm64: rsi: use linear-map alias for realm config buffer
rsi_get_realm_config() passes its argument to virt_to_phys(), but
&config is a kernel image address and not a linear-map alias.
On arm64 this triggers the below warning:

 virt_to_phys used for non-linear address: (____ptrval____) (config+0x0/0x1000)
 WARNING: arch/arm64/mm/physaddr.c:15 at __virt_to_phys+0x50/0x70, CPU#0: swapper/0
 Modules linked in:
 .....
 Hardware name: linux,dummy-virt (DT)
 pstate: 200000c5 (nzCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : __virt_to_phys+0x50/0x70
 lr : __virt_to_phys+0x4c/0x70
 .....
 ......
 Call trace:
  __virt_to_phys+0x50/0x70 (P)
  arm64_rsi_init+0xa0/0x1b8
  setup_arch+0x13c/0x1a0
  start_kernel+0x68/0x398
  __primary_switched+0x88/0x90

Pass lm_alias(&config) instead so the RSI call uses the linear-map
alias of the same buffer and avoids the boot-time warning.

Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-10 11:52:04 +01:00
Michael Ugrin
74b63934ab arm64: Kconfig: fix duplicate word in CMDLINE help text
Remove duplicate 'the' in the CMDLINE config help text.

Signed-off-by: Michael Ugrin <mugrinphoto@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-10 11:16:24 +01:00
Muhammad Usama Anjum
249bf97331 arm64: mte: Skip TFSR_EL1 checks and barriers in synchronous tag check mode
With KASAN_HW_TAGS (MTE) in synchronous mode, tag check faults are
reported as immediate Data Abort exceptions. The TFSR_EL1.TF1 bit is
never set since faults never go through the asynchronous path.
Therefore, reading TFSR_EL1 and executing data and instruction barriers
on kernel entry, exit, context switch and suspend is unnecessary
overhead.

As with the check_mte_async_tcf and clear_mte_async_tcf paths for
TFSRE0_EL1, extend the same optimisation to kernel entry/exit, context
switch and suspend.

All mte kselftests pass. The kunit before and after the patch show same
results.

A selection of test_vmalloc benchmarks running on a arm64 machine.
v6.19 is the baseline. (>0 is faster, <0 is slower, (R)/(I) =
statistically significant Regression/Improvement). Based on significance
and ignoring the noise, the benchmarks improved.

* 77 result classes were considered, with 9 wins, 0 losses and 68 ties

Results of fastpath [1] on v6.19 vs this patch:

+----------------------------+----------------------------------------------------------+------------+
| Benchmark                  | Result Class                                             |   barriers |
+============================+==========================================================+============+
| micromm/fork               | fork: p:1, d:10 (seconds)                                |  (I) 2.75% |
|                            | fork: p:512, d:10 (seconds)                              |      0.96% |
+----------------------------+----------------------------------------------------------+------------+
| micromm/munmap             | munmap: p:1, d:10 (seconds)                              |     -1.78% |
|                            | munmap: p:512, d:10 (seconds)                            |      5.02% |
+----------------------------+----------------------------------------------------------+------------+
| micromm/vmalloc            | fix_align_alloc_test: p:1, h:0, l:500000 (usec)          |     -0.56% |
|                            | fix_size_alloc_test: p:1, h:0, l:500000 (usec)           |      0.70% |
|                            | fix_size_alloc_test: p:4, h:0, l:500000 (usec)           |      1.18% |
|                            | fix_size_alloc_test: p:16, h:0, l:500000 (usec)          |     -5.01% |
|                            | fix_size_alloc_test: p:16, h:1, l:500000 (usec)          |     13.81% |
|                            | fix_size_alloc_test: p:64, h:0, l:100000 (usec)          |      6.51% |
|                            | fix_size_alloc_test: p:64, h:1, l:100000 (usec)          |     32.87% |
|                            | fix_size_alloc_test: p:256, h:0, l:100000 (usec)         |      4.17% |
|                            | fix_size_alloc_test: p:256, h:1, l:100000 (usec)         |      8.40% |
|                            | fix_size_alloc_test: p:512, h:0, l:100000 (usec)         |     -0.48% |
|                            | fix_size_alloc_test: p:512, h:1, l:100000 (usec)         |     -0.74% |
|                            | full_fit_alloc_test: p:1, h:0, l:500000 (usec)           |      0.53% |
|                            | kvfree_rcu_1_arg_vmalloc_test: p:1, h:0, l:500000 (usec) |     -2.81% |
|                            | kvfree_rcu_2_arg_vmalloc_test: p:1, h:0, l:500000 (usec) |     -2.06% |
|                            | long_busy_list_alloc_test: p:1, h:0, l:500000 (usec)     |     -0.56% |
|                            | pcpu_alloc_test: p:1, h:0, l:500000 (usec)               |     -0.41% |
|                            | random_size_align_alloc_test: p:1, h:0, l:500000 (usec)  |      0.89% |
|                            | random_size_alloc_test: p:1, h:0, l:500000 (usec)        |      1.71% |
|                            | vm_map_ram_test: p:1, h:0, l:500000 (usec)               |      0.83% |
+----------------------------+----------------------------------------------------------+------------+
| schbench/thread-contention | -m 16 -t 1 -r 10 -s 1000, avg_rps (req/sec)              |      0.05% |
|                            | -m 16 -t 1 -r 10 -s 1000, req_latency_p99 (usec)         |      0.60% |
|                            | -m 16 -t 1 -r 10 -s 1000, wakeup_latency_p99 (usec)      |      0.00% |
|                            | -m 16 -t 4 -r 10 -s 1000, avg_rps (req/sec)              |     -0.34% |
|                            | -m 16 -t 4 -r 10 -s 1000, req_latency_p99 (usec)         |     -0.58% |
|                            | -m 16 -t 4 -r 10 -s 1000, wakeup_latency_p99 (usec)      |      9.09% |
|                            | -m 16 -t 16 -r 10 -s 1000, avg_rps (req/sec)             |     -0.74% |
|                            | -m 16 -t 16 -r 10 -s 1000, req_latency_p99 (usec)        |     -1.40% |
|                            | -m 16 -t 16 -r 10 -s 1000, wakeup_latency_p99 (usec)     |      0.00% |
|                            | -m 16 -t 64 -r 10 -s 1000, avg_rps (req/sec)             |     -0.78% |
|                            | -m 16 -t 64 -r 10 -s 1000, req_latency_p99 (usec)        |     -0.11% |
|                            | -m 16 -t 64 -r 10 -s 1000, wakeup_latency_p99 (usec)     |      0.11% |
|                            | -m 16 -t 256 -r 10 -s 1000, avg_rps (req/sec)            |      2.64% |
|                            | -m 16 -t 256 -r 10 -s 1000, req_latency_p99 (usec)       |      3.15% |
|                            | -m 16 -t 256 -r 10 -s 1000, wakeup_latency_p99 (usec)    |     17.54% |
|                            | -m 32 -t 1 -r 10 -s 1000, avg_rps (req/sec)              |     -1.22% |
|                            | -m 32 -t 1 -r 10 -s 1000, req_latency_p99 (usec)         |      0.85% |
|                            | -m 32 -t 1 -r 10 -s 1000, wakeup_latency_p99 (usec)      |      0.00% |
|                            | -m 32 -t 4 -r 10 -s 1000, avg_rps (req/sec)              |     -0.34% |
|                            | -m 32 -t 4 -r 10 -s 1000, req_latency_p99 (usec)         |      1.05% |
|                            | -m 32 -t 4 -r 10 -s 1000, wakeup_latency_p99 (usec)      |      0.00% |
|                            | -m 32 -t 16 -r 10 -s 1000, avg_rps (req/sec)             |     -0.41% |
|                            | -m 32 -t 16 -r 10 -s 1000, req_latency_p99 (usec)        |      0.58% |
|                            | -m 32 -t 16 -r 10 -s 1000, wakeup_latency_p99 (usec)     |      2.13% |
|                            | -m 32 -t 64 -r 10 -s 1000, avg_rps (req/sec)             |      0.67% |
|                            | -m 32 -t 64 -r 10 -s 1000, req_latency_p99 (usec)        |      2.07% |
|                            | -m 32 -t 64 -r 10 -s 1000, wakeup_latency_p99 (usec)     |     -1.28% |
|                            | -m 32 -t 256 -r 10 -s 1000, avg_rps (req/sec)            |      1.01% |
|                            | -m 32 -t 256 -r 10 -s 1000, req_latency_p99 (usec)       |      0.69% |
|                            | -m 32 -t 256 -r 10 -s 1000, wakeup_latency_p99 (usec)    |     13.12% |
|                            | -m 64 -t 1 -r 10 -s 1000, avg_rps (req/sec)              |     -0.25% |
|                            | -m 64 -t 1 -r 10 -s 1000, req_latency_p99 (usec)         |     -0.48% |
|                            | -m 64 -t 1 -r 10 -s 1000, wakeup_latency_p99 (usec)      |     10.53% |
|                            | -m 64 -t 4 -r 10 -s 1000, avg_rps (req/sec)              |     -0.06% |
|                            | -m 64 -t 4 -r 10 -s 1000, req_latency_p99 (usec)         |      0.00% |
|                            | -m 64 -t 4 -r 10 -s 1000, wakeup_latency_p99 (usec)      |      0.00% |
|                            | -m 64 -t 16 -r 10 -s 1000, avg_rps (req/sec)             |     -0.36% |
|                            | -m 64 -t 16 -r 10 -s 1000, req_latency_p99 (usec)        |      0.52% |
|                            | -m 64 -t 16 -r 10 -s 1000, wakeup_latency_p99 (usec)     |      0.11% |
|                            | -m 64 -t 64 -r 10 -s 1000, avg_rps (req/sec)             |      0.52% |
|                            | -m 64 -t 64 -r 10 -s 1000, req_latency_p99 (usec)        |      3.53% |
|                            | -m 64 -t 64 -r 10 -s 1000, wakeup_latency_p99 (usec)     |     -0.10% |
|                            | -m 64 -t 256 -r 10 -s 1000, avg_rps (req/sec)            |      2.53% |
|                            | -m 64 -t 256 -r 10 -s 1000, req_latency_p99 (usec)       |      1.82% |
|                            | -m 64 -t 256 -r 10 -s 1000, wakeup_latency_p99 (usec)    |     -5.80% |
+----------------------------+----------------------------------------------------------+------------+
| syscall/getpid             | mean (ns)                                                | (I) 15.98% |
|                            | p99 (ns)                                                 | (I) 11.11% |
|                            | p99.9 (ns)                                               | (I) 16.13% |
+----------------------------+----------------------------------------------------------+------------+
| syscall/getppid            | mean (ns)                                                | (I) 14.82% |
|                            | p99 (ns)                                                 | (I) 17.86% |
|                            | p99.9 (ns)                                               |  (I) 9.09% |
+----------------------------+----------------------------------------------------------+------------+
| syscall/invalid            | mean (ns)                                                | (I) 17.78% |
|                            | p99 (ns)                                                 | (I) 11.11% |
|                            | p99.9 (ns)                                               |     13.33% |
+----------------------------+----------------------------------------------------------+------------+

[1] https://gitlab.arm.com/tooling/fastpath

Signed-off-by: Muhammad Usama Anjum <usama.anjum@arm.com>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Yeoreum Yun <yeoreum.yun@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-09 18:56:22 +01:00
Mark Brown
306736fd51 arm64/sysreg: Update ID_AA64SMFR0_EL1 description to DDI0601 2025-12
The 2025 extensions add FEAT_SME2P3, including LUT6.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-09 16:50:55 +01:00
Mark Brown
bf56250f34 arm64/sysreg: Update ID_AA64ZFR0_EL1 description to DDI0601 2025-12
The 2025 extensions add FEAT_SVE2P3 and FEAT_SVE_B16MM.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-09 16:50:55 +01:00
Mark Brown
d74576b51b arm64/sysreg: Update ID_AA64FPFR0_EL1 description to DDI0601 2025-12
The 2025 extensions add FEAT_F16MM and adjust some of the RES0 bits to be
RAZ instead as a placeholder for future extensions.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-09 16:50:55 +01:00
Mark Brown
bb5e1e5405 arm64/sysreg: Update ID_AA64ISAR2_EL1 description to DDI0601 2025-12
The 2025 extensions update the LUT field for new instructions added by
SVE and SME 2.3, there is no separate FEAT_ feature for these.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-09 16:50:55 +01:00
Mark Brown
b964aa8d68 arm64/sysreg: Update ID_AA64ISAR0_EL1 description to DDI0601 2025-12
The 2025 extensions add FEAT_F16F32DOT and FEAT_F16F32MM.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-09 16:50:55 +01:00
Mark Brown
abed23c3c4 arm64/hwcap: Generate the KERNEL_HWCAP_ definitions for the hwcaps
Currently for each hwcap we define both the HWCAPn_NAME definition which is
exposed to userspace and a kernel internal KERNEL_HWCAP_NAME definition
which we use internally. This is tedious and repetitive, instead use a
script to generate the KERNEL_HWCAP_ definitions from the UAPI definitions.

No functional changes intended.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-09 16:50:23 +01:00
Wang Wensheng
ee020bf6f1 arm64: kexec: Remove duplicate allocation for trans_pgd
trans_pgd would be allocated in trans_pgd_create_copy(), so remove the
duplicate allocation before calling trans_pgd_create_copy().

Fixes: 3744b5280e ("arm64: kexec: install a copy of the linear-map")
Signed-off-by: Wang Wensheng <wsw9603@163.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-08 17:49:08 +01:00
Haoyu Lu
b178330b67 ACPI: AGDI: fix missing newline in error message
Add the missing trailing newline to the dev_err() message
printed when SDEI event registration fails.

This keeps the error output as a properly terminated log line.

Fixes: a2a591fb76 ("ACPI: AGDI: Add driver for Arm Generic Diagnostic Dump and Reset device")
Reviewed-by: Ilkka Koskinen <ilkka@os.amperecomputing.com>
Signed-off-by: Haoyu Lu <hechushiguitu666@gmail.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-08 17:45:06 +01:00
Mark Rutland
8d13386c76 arm64: Check DAIF (and PMR) at task-switch time
When __switch_to() switches from a 'prev' task to a 'next' task, various
pieces of CPU state are expected to have specific values, such that
these do not need to be saved/restored. If any of these hold an
unexpected value when switching away from the prev task, they could lead
to surprising behaviour in the context of the next task, and it would be
difficult to determine where they were configured to their unexpected
value.

Add some checks for DAIF and PMR at task-switch time so that we can
detect such issues.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Will Deacon <will@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-08 17:40:04 +01:00
Mark Rutland
ae654112ea arm64: entry: Use split preemption logic
The generic irqentry code now provides
irqentry_exit_to_kernel_mode_preempt() and
irqentry_exit_to_kernel_mode_after_preempt(), which can be used
where architectures have different state requirements for involuntary
preemption and exception return, as is the case on arm64.

Use the new functions on arm64, aligning our exit to kernel mode logic
with the style of our exit to user mode logic. This removes the need for
the recently-added bodge in arch_irqentry_exit_need_resched(), and
allows preemption to occur when returning from any exception taken from
kernel mode, which is nicer for RT.

In an ideal world, we'd remove arch_irqentry_exit_need_resched(), and
fold the conditionality directly into the architecture-specific entry
code. That way all the logic necessary to avoid preempting from a
pseudo-NMI could be constrained specifically to the EL1 IRQ/FIQ paths,
avoiding redundant work for other exceptions, and making the flow a bit
clearer. At present it looks like that would require a larger
refactoring (e.g. for the PREEMPT_DYNAMIC logic), and so I've left that
as-is for now.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-08 17:40:04 +01:00
Mark Rutland
a07b7b2142 arm64: entry: Use irqentry_{enter_from,exit_to}_kernel_mode()
The generic irqentry code now provides irqentry_enter_from_kernel_mode()
and irqentry_exit_to_kernel_mode(), which can be used when an exception
is known to be taken from kernel mode. These can be inlined into
architecture-specific entry code, and avoid redundant work to test
whether the exception was taken from user mode.

Use these in arm64_enter_from_kernel_mode() and
arm64_exit_to_kernel_mode(), which are only used for exceptions known to
be taken from kernel mode. This will remove a small amount of redundant
work, and will permit further changes to arm64_exit_to_kernel_mode() in
subsequent patches.

There should be no funcitonal change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-08 17:40:04 +01:00
Mark Rutland
6879ef1302 arm64: entry: Consistently prefix arm64-specific wrappers
For historical reasons, arm64's entry code has arm64-specific functions
named enter_from_kernel_mode() and exit_to_kernel_mode(), which are
wrappers for similarly-named functions from the generic irqentry code.
Other arm64-specific wrappers have an 'arm64_' prefix to clearly
distinguish them from their generic counterparts, e.g.
arm64_enter_from_user_mode() and arm64_exit_to_user_mode().

For consistency and clarity, add an 'arm64_' prefix to these functions.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-08 17:40:04 +01:00
Mark Rutland
2371bd83b3 arm64: entry: Don't preempt with SError or Debug masked
On arm64, involuntary kernel preemption has been subtly broken since the
move to the generic irqentry code. When preemption occurs, the new task
may run with SError and Debug exceptions masked unexpectedly, leading to
a loss of RAS events, breakpoints, watchpoints, and single-step
exceptions.

Prior to moving to the generic irqentry code, involuntary preemption of
kernel mode would only occur when returning from regular interrupts, in
a state where interrupts were masked and all other arm64-specific
exceptions (SError, Debug, and pseudo-NMI) were unmasked. This is the
only state in which it is valid to switch tasks.

As part of moving to the generic irqentry code, the involuntary
preemption logic was moved such that involuntary preemption could occur
when returning from any (non-NMI) exception. As most exception handlers
mask all arm64-specific exceptions before this point, preemption could
occur in a state where arm64-specific exceptions were masked. This is
not a valid state to switch tasks, and resulted in the loss of
exceptions described above.

As a temporary bodge, avoid the loss of exceptions by avoiding
involuntary preemption when SError and/or Debug exceptions are masked.
Practically speaking this means that involuntary preemption will only
occur when returning from regular interrupts, as was the case before
moving to the generic irqentry code.

Fixes: 99eb057ccd ("arm64: entry: Move arm64_preempt_schedule_irq() into __exit_to_kernel_mode()")
Reported-by: Ada Couprie Diaz <ada.coupriediaz@arm.com>
Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Jinjie Ruan <ruanjinjie@huawei.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-08 17:40:04 +01:00
Mark Rutland
041aa7a853 entry: Split preemption from irqentry_exit_to_kernel_mode()
Some architecture-specific work needs to be performed between the state
management for exception entry/exit and the "real" work to handle the
exception. For example, arm64 needs to manipulate a number of exception
masking bits, with different exceptions requiring different masking.

Generally this can all be hidden in the architecture code, but for arm64
the current structure of irqentry_exit_to_kernel_mode() makes this
particularly difficult to handle in a way that is correct, maintainable,
and efficient.

The gory details are described in the thread surrounding:

  https://lore.kernel.org/lkml/acPAzdtjK5w-rNqC@J2N7QTR9R3/

The summary is:

* Currently, irqentry_exit_to_kernel_mode() handles both involuntary
  preemption AND state management necessary for exception return.

* When scheduling (including involuntary preemption), arm64 needs to
  have all arm64-specific exceptions unmasked, though regular interrupts
  must be masked.

* Prior to the state management for exception return, arm64 needs to
  mask a number of arm64-specific exceptions, and perform some work with
  these exceptions masked (with RCU watching, etc).

While in theory it is possible to handle this with a new arch_*() hook
called somewhere under irqentry_exit_to_kernel_mode(), this is fragile
and complicated, and doesn't match the flow used for exception return to
user mode, which has a separate 'prepare' step (where preemption can
occur) prior to the state management.

To solve this, refactor irqentry_exit_to_kernel_mode() to match the
style of {irqentry,syscall}_exit_to_user_mode(), moving preemption logic
into a new irqentry_exit_to_kernel_mode_preempt() function, and moving
state management in a new irqentry_exit_to_kernel_mode_after_preempt()
function. The existing irqentry_exit_to_kernel_mode() is left as a
caller of both of these, avoiding the need to modify existing callers.

There should be no functional change as a result of this change.

[ tglx: Updated kernel doc ]

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260407131650.3813777-6-mark.rutland@arm.com
2026-04-08 11:43:32 +02:00
Mark Rutland
c5538d0141 entry: Split kernel mode logic from irqentry_{enter,exit}()
The generic irqentry code has entry/exit functions specifically for
exceptions taken from user mode, but doesn't have entry/exit functions
specifically for exceptions taken from kernel mode.

It would be helpful to have separate entry/exit functions specifically
for exceptions taken from kernel mode. This would make the structure of
the entry code more consistent, and would make it easier for
architectures to manage logic specific to exceptions taken from kernel
mode.

Move the logic specific to kernel mode out of irqentry_enter() and
irqentry_exit() into new irqentry_enter_from_kernel_mode() and
irqentry_exit_to_kernel_mode() functions. These are marked
__always_inline and placed in irq-entry-common.h, as with
irqentry_enter_from_user_mode() and irqentry_exit_to_user_mode(), so
that they can be inlined into architecture-specific wrappers. The
existing out-of-line irqentry_enter() and irqentry_exit() functions
retained as callers of the new functions.

The lockdep assertion from irqentry_exit() is moved into
irqentry_exit_to_user_mode() and irqentry_exit_to_kernel_mode(). This
was previously missing from irqentry_exit_to_user_mode() when called
directly, and any new lockdep assertion failure relating from this
change is a latent bug.

Aside from the lockdep change noted above, there should be no functional
change as a result of this change.

[ tglx: Updated kernel doc ]

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260407131650.3813777-5-mark.rutland@arm.com
2026-04-08 11:43:32 +02:00
Mark Rutland
eb1b51afde entry: Move irqentry_enter() prototype later
Subsequent patches will rework the irqentry_*() functions. The end
result (and the intermediate diffs) will be much clearer if the
prototype for the irqentry_enter() function is moved later, immediately
before the prototype of the irqentry_exit() function.

Move the prototype later.

This is purely a move; there should be no functional change as a result
of this change.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260407131650.3813777-4-mark.rutland@arm.com
2026-04-08 11:43:31 +02:00
Mark Rutland
22f66e7ef4 entry: Remove local_irq_{enable,disable}_exit_to_user()
local_irq_enable_exit_to_user() and local_irq_disable_exit_to_user() are
never overridden by architecture code, and are always equivalent to
local_irq_enable() and local_irq_disable().

These functions were added on the assumption that arm64 would override
them to manage 'DAIF' exception masking, as described by Thomas Gleixner
in these threads:

  https://lore.kernel.org/all/20190919150809.340471236@linutronix.de/
  https://lore.kernel.org/all/alpine.DEB.2.21.1910240119090.1852@nanos.tec.linutronix.de/

In practice arm64 did not need to override either. Prior to moving to
the generic irqentry code, arm64's management of DAIF was reworked in
commit:

  97d935faac ("arm64: Unmask Debug + SError in do_notify_resume()")

Since that commit, arm64 only masks interrupts during the 'prepare' step
when returning to user mode, and masks other DAIF exceptions later.
Within arm64_exit_to_user_mode(), the arm64 entry code is as follows:

	local_irq_disable();
	exit_to_user_mode_prepare_legacy(regs);
	local_daif_mask();
	mte_check_tfsr_exit();
	exit_to_user_mode();

Remove the unnecessary local_irq_enable_exit_to_user() and
local_irq_disable_exit_to_user() functions.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260407131650.3813777-3-mark.rutland@arm.com
2026-04-08 11:43:31 +02:00
Mark Rutland
1f0d117cd6 entry: Fix stale comment for irqentry_enter()
The kerneldoc comment for irqentry_enter() refers to idtentry_exit(),
which is an accidental holdover from the x86 entry code that the generic
irqentry code was based on.

Correct this to refer to irqentry_exit().

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Jinjie Ruan <ruanjinjie@huawei.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260407131650.3813777-2-mark.rutland@arm.com
2026-04-08 11:43:31 +02:00
Mark Brown
85b6f920a8 arm64/sysreg: Update SMIDR_EL1 to DDI0601 2025-06
Update the definition of SMIDR_EL1 in the sysreg definition to reflect the
information in DD0601 2025-06. This includes somewhat more generic ways of
describing the sharing of SMCUs, more information on supported priorities
and provides additional resolution for describing affinity groups.

Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-02 21:48:21 +01:00
Ryan Roberts
1d37713fa8 arm64: mm: Remove pmd_sect() and pud_sect()
The semantics of pXd_leaf() are very similar to pXd_sect(). The only
difference is that pXd_sect() only considers it a section if PTE_VALID
is set, whereas pXd_leaf() permits both "valid" and "present-invalid"
types.

Using pXd_sect() has caused issues now that large leaf entries can be
present-invalid since commit a166563e7e ("arm64: mm: support large
block mapping when rodata=full"), so let's just remove the API and
standardize on pXd_leaf().

There are a few callsites of the form pXd_leaf(READ_ONCE(*pXdp)). This
was previously fine for the pXd_sect() macro because it only evaluated
its argument once. But pXd_leaf() evaluates its argument multiple times.
So let's avoid unintended side effects by reimplementing pXd_leaf() as
an inline function.

Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-02 20:49:16 +01:00
Ryan Roberts
15bfba1ad7 arm64: mm: Handle invalid large leaf mappings correctly
It has been possible for a long time to mark ptes in the linear map as
invalid. This is done for secretmem, kfence, realm dma memory un/share,
and others, by simply clearing the PTE_VALID bit. But until commit
a166563e7e ("arm64: mm: support large block mapping when
rodata=full") large leaf mappings were never made invalid in this way.

It turns out various parts of the code base are not equipped to handle
invalid large leaf mappings (in the way they are currently encoded) and
I've observed a kernel panic while booting a realm guest on a
BBML2_NOABORT system as a result:

[   15.432706] software IO TLB: Memory encryption is active and system is using DMA bounce buffers
[   15.476896] Unable to handle kernel paging request at virtual address ffff000019600000
[   15.513762] Mem abort info:
[   15.527245]   ESR = 0x0000000096000046
[   15.548553]   EC = 0x25: DABT (current EL), IL = 32 bits
[   15.572146]   SET = 0, FnV = 0
[   15.592141]   EA = 0, S1PTW = 0
[   15.612694]   FSC = 0x06: level 2 translation fault
[   15.640644] Data abort info:
[   15.661983]   ISV = 0, ISS = 0x00000046, ISS2 = 0x00000000
[   15.694875]   CM = 0, WnR = 1, TnD = 0, TagAccess = 0
[   15.723740]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[   15.755776] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000081f3f000
[   15.800410] [ffff000019600000] pgd=0000000000000000, p4d=180000009ffff403, pud=180000009fffe403, pmd=00e8000199600704
[   15.855046] Internal error: Oops: 0000000096000046 [#1]  SMP
[   15.886394] Modules linked in:
[   15.900029] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 7.0.0-rc4-dirty #4 PREEMPT
[   15.935258] Hardware name: linux,dummy-virt (DT)
[   15.955612] pstate: 21400005 (nzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--)
[   15.986009] pc : __pi_memcpy_generic+0x128/0x22c
[   16.006163] lr : swiotlb_bounce+0xf4/0x158
[   16.024145] sp : ffff80008000b8f0
[   16.038896] x29: ffff80008000b8f0 x28: 0000000000000000 x27: 0000000000000000
[   16.069953] x26: ffffb3976d261ba8 x25: 0000000000000000 x24: ffff000019600000
[   16.100876] x23: 0000000000000001 x22: ffff0000043430d0 x21: 0000000000007ff0
[   16.131946] x20: 0000000084570010 x19: 0000000000000000 x18: ffff00001ffe3fcc
[   16.163073] x17: 0000000000000000 x16: 00000000003fffff x15: 646e612065766974
[   16.194131] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000
[   16.225059] x11: 0000000000000000 x10: 0000000000000010 x9 : 0000000000000018
[   16.256113] x8 : 0000000000000018 x7 : 0000000000000000 x6 : 0000000000000000
[   16.287203] x5 : ffff000019607ff0 x4 : ffff000004578000 x3 : ffff000019600000
[   16.318145] x2 : 0000000000007ff0 x1 : ffff000004570010 x0 : ffff000019600000
[   16.349071] Call trace:
[   16.360143]  __pi_memcpy_generic+0x128/0x22c (P)
[   16.380310]  swiotlb_tbl_map_single+0x154/0x2b4
[   16.400282]  swiotlb_map+0x5c/0x228
[   16.415984]  dma_map_phys+0x244/0x2b8
[   16.432199]  dma_map_page_attrs+0x44/0x58
[   16.449782]  virtqueue_map_page_attrs+0x38/0x44
[   16.469596]  virtqueue_map_single_attrs+0xc0/0x130
[   16.490509]  virtnet_rq_alloc.isra.0+0xa4/0x1fc
[   16.510355]  try_fill_recv+0x2a4/0x584
[   16.526989]  virtnet_open+0xd4/0x238
[   16.542775]  __dev_open+0x110/0x24c
[   16.558280]  __dev_change_flags+0x194/0x20c
[   16.576879]  netif_change_flags+0x24/0x6c
[   16.594489]  dev_change_flags+0x48/0x7c
[   16.611462]  ip_auto_config+0x258/0x1114
[   16.628727]  do_one_initcall+0x80/0x1c8
[   16.645590]  kernel_init_freeable+0x208/0x2f0
[   16.664917]  kernel_init+0x24/0x1e0
[   16.680295]  ret_from_fork+0x10/0x20
[   16.696369] Code: 927cec03 cb0e0021 8b0e0042 a9411c26 (a900340c)
[   16.723106] ---[ end trace 0000000000000000 ]---
[   16.752866] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[   16.792556] Kernel Offset: 0x3396ea200000 from 0xffff800080000000
[   16.818966] PHYS_OFFSET: 0xfff1000080000000
[   16.837237] CPU features: 0x0000000,00060005,13e38581,957e772f
[   16.862904] Memory Limit: none
[   16.876526] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---

This panic occurs because the swiotlb memory was previously shared to
the host (__set_memory_enc_dec()), which involves transitioning the
(large) leaf mappings to invalid, sharing to the host, then marking the
mappings valid again. But pageattr_p[mu]d_entry() would only update the
entry if it is a section mapping, since otherwise it concluded it must
be a table entry so shouldn't be modified. But p[mu]d_sect() only
returns true if the entry is valid. So the result was that the large
leaf entry was made invalid in the first pass then ignored in the second
pass. It remains invalid until the above code tries to access it and
blows up.

The simple fix would be to update pageattr_pmd_entry() to use
!pmd_table() instead of pmd_sect(). That would solve this problem.

But the ptdump code also suffers from a similar issue. It checks
pmd_leaf() and doesn't call into the arch-specific note_page() machinery
if it returns false. As a result of this, ptdump wasn't even able to
show the invalid large leaf mappings; it looked like they were valid
which made this super fun to debug. the ptdump code is core-mm and
pmd_table() is arm64-specific so we can't use the same trick to solve
that.

But we already support the concept of "present-invalid" for user space
entries. And even better, pmd_leaf() will return true for a leaf mapping
that is marked present-invalid. So let's just use that encoding for
present-invalid kernel mappings too. Then we can use pmd_leaf() where we
previously used pmd_sect() and everything is magically fixed.

Additionally, from inspection kernel_page_present() was broken in a
similar way, so I'm also updating that to use pmd_leaf().

The transitional page tables component was also similarly broken; it
creates a copy of the kernel page tables, making RO leaf mappings RW in
the process. It also makes invalid (but-not-none) pte mappings valid.
But it was not doing this for large leaf mappings. This could have
resulted in crashes at kexec- or hibernate-time. This code is fixed to
flip "present-invalid" mappings back to "present-valid" at all levels.

Finally, I have hardened split_pmd()/split_pud() so that if it is passed
a "present-invalid" leaf, it will maintain that property in the split
leaves, since I wasn't able to convince myself that it would only ever
be called for "present-valid" leaves.

Fixes: a166563e7e ("arm64: mm: support large block mapping when rodata=full")
Cc: stable@vger.kernel.org
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-02 20:49:16 +01:00
Ryan Roberts
f12b435de2 arm64: mm: Fix rodata=full block mapping support for realm guests
Commit a166563e7e ("arm64: mm: support large block mapping when
rodata=full") enabled the linear map to be mapped by block/cont while
still allowing granular permission changes on BBML2_NOABORT systems by
lazily splitting the live mappings. This mechanism was intended to be
usable by realm guests since they need to dynamically share dma buffers
with the host by "decrypting" them - which for Arm CCA, means marking
them as shared in the page tables.

However, it turns out that the mechanism was failing for realm guests
because realms need to share their dma buffers (via
__set_memory_enc_dec()) much earlier during boot than
split_kernel_leaf_mapping() was able to handle. The report linked below
showed that GIC's ITS was one such user. But during the investigation I
found other callsites that could not meet the
split_kernel_leaf_mapping() constraints.

The problem is that we block map the linear map based on the boot CPU
supporting BBML2_NOABORT, then check that all the other CPUs support it
too when finalizing the caps. If they don't, then we stop_machine() and
split to ptes. For safety, split_kernel_leaf_mapping() previously
wouldn't permit splitting until after the caps were finalized. That
ensured that if any secondary cpus were running that didn't support
BBML2_NOABORT, we wouldn't risk breaking them.

I've fix this problem by reducing the black-out window where we refuse
to split; there are now 2 windows. The first is from T0 until the page
allocator is inititialized. Splitting allocates memory for the page
allocator so it must be in use. The second covers the period between
starting to online the secondary cpus until the system caps are
finalized (this is a very small window).

All of the problematic callers are calling __set_memory_enc_dec() before
the secondary cpus come online, so this solves the problem. However, one
of these callers, swiotlb_update_mem_attributes(), was trying to split
before the page allocator was initialized. So I have moved this call
from arch_mm_preinit() to mem_init(), which solves the ordering issue.

I've added warnings and return an error if any attempt is made to split
in the black-out windows.

Note there are other issues which prevent booting all the way to user
space, which will be fixed in subsequent patches.

Reported-by: Jinjiang Tu <tujinjiang@huawei.com>
Closes: https://lore.kernel.org/all/0b2a4ae5-fc51-4d77-b177-b2e9db74f11d@huawei.com/
Fixes: a166563e7e ("arm64: mm: support large block mapping when rodata=full")
Cc: stable@vger.kernel.org
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-02 20:49:16 +01:00
Kevin Brodsky
5e0deb0a6b arm64: mm: Use generic enum pgtable_level
enum pgtable_type was introduced for arm64 by commit c64f46ee13
("arm64: mm: use enum to identify pgtable level instead of
*_SHIFT"). In the meantime, the generic enum pgtable_level got
introduced by commit b22cc9a9c7 ("mm/rmap: convert "enum
rmap_level" to "enum pgtable_level"").

Let's switch to the generic enum pgtable_level. The only difference
is that it also includes PGD level; __pgd_pgtable_alloc() isn't
expected to create PGD tables so we add a VM_WARN_ON() for that
case.

Suggested-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-01 18:20:12 +01:00
Anshuman Khandual
95a58852b0 arm64/mm: Reject memory removal that splits a kernel leaf mapping
Linear and vmemmap mappings that get torn down during a memory hot remove
operation might contain leaf level entries on any page table level. If the
requested memory range's linear or vmemmap mappings falls within such leaf
entries, new mappings need to be created for the remaining memory mapped on
the leaf entry earlier, following standard break before make aka BBM rules.
But kernel cannot tolerate BBM and hence remapping to fine grained leaves
would not be possible on systems without BBML2_NOABORT.

Currently memory hot remove operation does not perform such restructuring,
and so removing memory ranges that could split a kernel leaf level mapping
need to be rejected.

While memory_hotplug.c does appear to permit hot removing arbitrary ranges
of memory, the higher layers that drive memory_hotplug (e.g. ACPI, virtio,
...) all appear to treat memory as fixed size devices. So it is impossible
to hot unplug a different amount than was previously hot plugged, and hence
we should never see a rejection in practice, but adding the check makes us
robust against a future change.

Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/all/aWZYXhrT6D2M-7-N@willie-the-truck/
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Suggested-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-01 18:04:54 +01:00
Anshuman Khandual
48478b9f79 arm64/mm: Enable batched TLB flush in unmap_hotplug_range()
During a memory hot remove operation, both linear and vmemmap mappings for
the memory range being removed, get unmapped via unmap_hotplug_range() but
mapped pages get freed only for vmemmap mapping. This is just a sequential
operation where each table entry gets cleared, followed by a leaf specific
TLB flush, and then followed by memory free operation when applicable.

This approach was simple and uniform both for vmemmap and linear mappings.
But linear mapping might contain CONT marked block memory where it becomes
necessary to first clear out all entire in the range before a TLB flush.
This is as per the architecture requirement. Hence batch all TLB flushes
during the table tear down walk and finally do it in unmap_hotplug_range().

Prior to this fix, it was hypothetically possible for a speculative access
to a higher address in the contiguous block to fill the TLB with shattered
entries for the entire contiguous range after a lower address had already
been cleared and invalidated. Due to the table entries being shattered, the
subsequent TLB invalidation for the higher address would not then clear the
TLB entries for the lower address, meaning stale TLB entries could persist.

Besides it also helps in improving the performance via TLBI range operation
along with reduced synchronization instructions. The time spent executing
unmap_hotplug_range() improved 97% measured over a 2GB memory hot removal
in KVM guest.

This scheme is not applicable during vmemmap mapping tear down where memory
needs to be freed and hence a TLB flush is required after clearing out page
table entry.

Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Closes: https://lore.kernel.org/all/aWZYXhrT6D2M-7-N@willie-the-truck/
Fixes: bbd6ec605c ("arm64/mm: Enable memory hot remove")
Cc: stable@vger.kernel.org
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-04-01 18:04:54 +01:00
Yeoreum Yun
e223258ed8 arm64: armv8_deprecated: Disable swp emulation when FEAT_LSUI present
The purpose of supporting LSUI is to eliminate PAN toggling. CPUs that
support LSUI are unlikely to support a 32-bit runtime. Rather than
emulating the SWP instruction using LSUI instructions in order to remove
PAN toggling, simply disable SWP emulation.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
[catalin.marinas@arm.com: some tweaks to the in-code comment]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-03-27 17:29:10 +00:00
Ben Horgan
4ce0a2ccc0 arm64: mpam: Add initial MPAM documentation
MPAM (Memory Partitioning and Monitoring) is now exposed to user-space via
resctrl. Add some documentation so the user knows what features to expect.

Reviewed-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.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>
2026-03-27 15:32:52 +00:00
James Morse
aeb8595a5f arm_mpam: Quirk CMN-650's CSU NRDY behaviour
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>
2026-03-27 15:32:42 +00:00
Shanker Donthineni
dc48eb1ff2 arm_mpam: Add workaround for T241-MPAM-6
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>
2026-03-27 15:32:41 +00:00
Shanker Donthineni
a7efe23ed6 arm_mpam: Add workaround for T241-MPAM-4
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>
2026-03-27 15:32:41 +00:00
Shanker Donthineni
70e81fbedc arm_mpam: Add workaround for T241-MPAM-1
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>
2026-03-27 15:32:41 +00:00
Shanker Donthineni
fa7745218c arm_mpam: Add quirk framework
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>
2026-03-27 15:32:27 +00:00
James Morse
fb481ec086 arm_mpam: resctrl: Call resctrl_init() on platforms that can support resctrl
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>
2026-03-27 15:32:19 +00:00
James Morse
4aab135bda arm64: mpam: Select ARCH_HAS_CPU_RESCTRL
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>
2026-03-27 15:32:11 +00:00
James Morse
efc775eadc arm_mpam: resctrl: Add empty definitions for assorted resctrl functions
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>
2026-03-27 15:32:04 +00:00
James Morse
49b04e4018 arm_mpam: resctrl: Update the rmid reallocation limit
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>
2026-03-27 15:31:57 +00:00
James Morse
fb56b29932 arm_mpam: resctrl: Add resctrl_arch_rmid_read()
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>
2026-03-27 15:31:50 +00:00
James Morse
2a3c79c615 arm_mpam: resctrl: Allow resctrl to allocate monitors
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>
2026-03-27 15:31:38 +00:00
James Morse
1458c4f053 arm_mpam: resctrl: Add support for csu counters
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>
2026-03-27 15:31:23 +00:00
Ben Horgan
264c285999 arm_mpam: resctrl: Add monitor initialisation and domain boilerplate
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>
2026-03-27 15:31:10 +00:00