kernel/linux.git/drivers/resctrl, branch v7.0-rc7

arm_mpam: Force __iomem casts

2026-03-13T14:17:30+00:00

Code allocates standard kernel memory to pass to the MPAM, which expects __iomem. The code is safe, because __iomem accessors should work fine on kernel mapped memory, however leads to sparse warnings: test_mpam_devices.c:327:42: warning: incorrect type in initializer (different address spaces) test_mpam_devices.c:327:42: expected char [noderef] __iomem *buf test_mpam_devices.c:327:42: got void * test_mpam_devices.c:342:24: warning: cast removes address space '__iomem' of expression Cast the pointer to memory via __force to silence them. Signed-off-by: Krzysztof Kozlowski Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202512160133.eAzPdJv2-lkp@intel.com/ Acked-by: Ben Horgan Signed-off-by: James Morse Signed-off-by: Will Deacon

arm_mpam: Disable preemption when making accesses to fake MSC in kunit test

2026-03-13T14:17:30+00:00

Accesses to MSC must be made from a cpu that is affine to that MSC and the driver checks this in __mpam_write_reg() using smp_processor_id(). A fake in-memory MSC is used for testing. When using that, it doesn't matter which cpu we access it from but calling smp_processor_id() from a preemptible context gives warnings when running with CONFIG_DEBUG_PREEMPT. Add a test helper that wraps mpam_reset_msc_bitmap() with preemption disabled to ensure all (fake) MSC accesses are made with preemption disabled. Signed-off-by: Ben Horgan Reviewed-by: James Morse Signed-off-by: James Morse Signed-off-by: Will Deacon

arm_mpam: Fix null pointer dereference when restoring bandwidth counters

2026-03-13T14:17:30+00:00

When an MSC supporting memory bandwidth monitoring is brought offline and then online, mpam_restore_mbwu_state() calls __ris_msmon_read() via ipi to restore the configuration of the bandwidth counters. It doesn't care about the value read, mbwu_arg.val, and doesn't set it leading to a null pointer dereference when __ris_msmon_read() adds to it. This results in a kernel oops with a call trace such as: Call trace: __ris_msmon_read+0x19c/0x64c (P) mpam_restore_mbwu_state+0xa0/0xe8 smp_call_on_cpu_callback+0x1c/0x38 process_one_work+0x154/0x4b4 worker_thread+0x188/0x310 kthread+0x11c/0x130 ret_from_fork+0x10/0x20 Provide a local variable for val to avoid __ris_msmon_read() dereferencing a null pointer when adding to val. Fixes: 41e8a14950e1 ("arm_mpam: Track bandwidth counter state for power management") Signed-off-by: Ben Horgan Reviewed-by: James Morse Signed-off-by: James Morse Signed-off-by: Will Deacon

Convert remaining multi-line kmalloc_obj/flex GFP_KERNEL uses

2026-02-22T16:26:33+00:00

Conversion performed via this Coccinelle script: // SPDX-License-Identifier: GPL-2.0-only // Options: --include-headers-for-types --all-includes --include-headers --keep-comments virtual patch @gfp depends on patch && !(file in "tools") && !(file in "samples")@ identifier ALLOC = {kmalloc_obj,kmalloc_objs,kmalloc_flex, kzalloc_obj,kzalloc_objs,kzalloc_flex, kvmalloc_obj,kvmalloc_objs,kvmalloc_flex, kvzalloc_obj,kvzalloc_objs,kvzalloc_flex}; @@ ALLOC(... - , GFP_KERNEL ) $ make coccicheck MODE=patch COCCI=gfp.cocci Build and boot tested x86_64 with Fedora 42's GCC and Clang: Linux version 6.19.0+ (user@host) (gcc (GCC) 15.2.1 20260123 (Red Hat 15.2.1-7), GNU ld version 2.44-12.fc42) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Linux version 6.19.0+ (user@host) (clang version 20.1.8 (Fedora 20.1.8-4.fc42), LLD 20.1.8) #1 SMP PREEMPT_DYNAMIC 1970-01-01 Signed-off-by: Kees Cook Signed-off-by: Linus Torvalds

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

arm_mpam: Use non-atomic bitops when modifying feature bitmap

2026-01-16T12:04:20+00:00

In the test__props_mismatch() kunit test we rely on the struct mpam_props being packed to ensure memcmp doesn't consider packing. Making it packed reduces the alignment of the features bitmap and so breaks a requirement for the use of atomics. As we don't rely on the set/clear of these bits being atomic, just make them non-atomic. Reviewed-by: Jonathan Cameron Signed-off-by: Ben Horgan Fixes: 8c90dc68a5de ("arm_mpam: Probe the hardware features resctrl supports") Reviewed-by: Gavin Shan Tested-by: Shaopeng Tan Tested-by: Peter Newman Signed-off-by: Catalin Marinas

arm_mpam: Remove duplicate linux/srcu.h header

2026-01-16T12:04:20+00:00

./drivers/resctrl/mpam_internal.h: linux/srcu.h is included more than once. Reviewed-by: Jonathan Cameron Reported-by: Abaci Robot Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=27328 Signed-off-by: Jiapeng Chong Acked-by: James Morse [BH: Keep alphabetical order] Signed-off-by: Ben Horgan Reviewed-by: Gavin Shan Reviewed-by: Fenghua Yu Tested-by: Shaopeng Tan Tested-by: Peter Newman Signed-off-by: Catalin Marinas

arm_mpam: Stop using uninitialized variables in __ris_msmon_read()

2026-01-08T19:03:15+00:00

Dan has reported two uses of uninitialized variables in __ris_msmon_read(). If an unknown monitor type is encountered then the local variable, now, is used uninitialized. Fix this by returning early on error. If a non-mbwu monitor is being read then the local variable, overflow, is not initialized but still read. Initialize it to false as overflow is not relevant for csu monitors. Fixes: 823e7c3712c5 ("arm_mpam: Add mpam_msmon_read() to read monitor value") Fixes: 9e5afb7c3283 ("arm_mpam: Use long MBWU counters if supported") Reported-by: kernel test robot Reported-by: Dan Carpenter Closes: https://lore.kernel.org/r/202512091519.RBwiJcSq-lkp@intel.com/ Closes: https://lore.kernel.org/r/202512100547.N7QPYgfb-lkp@intel.com/ Signed-off-by: Ben Horgan Reviewed-by: Jonathan Cameron Signed-off-by: Catalin Marinas

arm_mpam: Add kunit tests for props_mismatch()

2025-11-19T18:34:24+00:00

When features are mismatched between MSC the way features are combined to the class determines whether resctrl can support this SoC. Add some tests to illustrate the sort of thing that is expected to work, and those that must be removed. Signed-off-by: James Morse Reviewed-by: Ben Horgan Reviewed-by: Fenghua Yu Reviewed-by: Gavin Shan Reviewed-by: Shaopeng Tan Tested-by: Fenghua Yu Tested-by: Carl Worth Tested-by: Gavin Shan Tested-by: Zeng Heng Tested-by: Shaopeng Tan Tested-by: Hanjun Guo Signed-off-by: Ben Horgan Signed-off-by: Catalin Marinas