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2025-03-25x86/cacheinfo: Relocate CPUID leaf 0x4 cache_type mappingAhmed S. Darwish
The cache_type_map[] array is used to map Intel leaf 0x4 cache_type values to their corresponding types at <linux/cacheinfo.h>. Move that array's definition after the actual CPUID leaf 0x4 structures, instead of having it in the middle of AMD leaf 0x4 emulation code. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-28-darwi@linutronix.de
2025-03-25x86/cacheinfo: Extract out cache self-snoop checksAhmed S. Darwish
The logic of not doing a cache flush if the CPU declares cache self snooping support is repeated across the x86/cacheinfo code. Extract it into its own function. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-27-darwi@linutronix.de
2025-03-25x86/cacheinfo: Extract out cache level topology ID calculationAhmed S. Darwish
For Intel CPUID leaf 0x4 parsing, refactor the cache level topology ID calculation code into its own method instead of repeating the same logic twice for L2 and L3. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-26-darwi@linutronix.de
2025-03-25x86/cacheinfo: Separate Intel CPUID leaf 0x4 handlingAhmed S. Darwish
init_intel_cacheinfo() was overly complex. It parsed leaf 0x4 data, leaf 0x2 data, and performed post-processing, all within one function. Parent commit moved leaf 0x2 parsing and the post-processing logic into their own functions. Continue the refactoring by extracting leaf 0x4 parsing into its own function. Initialize local L2/L3 topology ID variables to BAD_APICID by default, thus ensuring they can be used unconditionally. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-25-darwi@linutronix.de
2025-03-25x86/cacheinfo: Separate CPUID leaf 0x2 handling and post-processing logicAhmed S. Darwish
The logic of init_intel_cacheinfo() is quite convoluted: it mixes leaf 0x4 parsing, leaf 0x2 parsing, plus some post-processing, in a single place. Begin simplifying its logic by extracting the leaf 0x2 parsing code, and the post-processing logic, into their own functions. While at it, rework the SMT LLC topology ID comment for clarity. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-24-darwi@linutronix.de
2025-03-25x86/cpu: Use consolidated CPUID leaf 0x2 descriptor tableAhmed S. Darwish
CPUID leaf 0x2 output is a stream of one-byte descriptors, each implying certain details about the CPU's cache and TLB entries. At previous commits, the mapping tables for such descriptors were merged into one consolidated table. The mapping was also transformed into a hash lookup instead of a loop-based lookup for each descriptor. Use the new consolidated table and its hash-based lookup through the for_each_leaf_0x2_tlb_entry() accessor. Remove the TLB-specific mapping, intel_tlb_table[], as it is now no longer used. Remove the <cpuid/types.h> macro, for_each_leaf_0x2_desc(), since the converted code was its last user. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-23-darwi@linutronix.de
2025-03-25x86/cacheinfo: Use consolidated CPUID leaf 0x2 descriptor tableAhmed S. Darwish
CPUID leaf 0x2 output is a stream of one-byte descriptors, each implying certain details about the CPU's cache and TLB entries. At previous commits, the mapping tables for such descriptors were merged into one consolidated table. The mapping was also transformed into a hash lookup instead of a loop-based lookup for each descriptor. Use the new consolidated table and its hash-based lookup through the for_each_leaf_0x2_tlb_entry() accessor. Remove the old cache-specific mapping, cache_table[], as it is no longer used. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-22-darwi@linutronix.de
2025-03-25x86/cpu: Consolidate CPUID leaf 0x2 tablesThomas Gleixner
CPUID leaf 0x2 describes TLBs and caches. So there are two tables with the respective descriptor constants in intel.c and cacheinfo.c. The tables occupy almost 600 byte and require a loop based lookup for each variant. Combining them into one table occupies exactly 1k rodata and allows to get rid of the loop based lookup by just using the descriptor byte provided by CPUID leaf 0x2 as index into the table, which simplifies the code and reduces text size. The conversion of the intel.c and cacheinfo.c code is done separately. [ darwi: Actually define struct leaf_0x2_table. Tab-align all of cpuid_0x2_table[] mapping entries. Define needed SZ_* macros at <linux/sizes.h> instead (merged commit.) Use CACHE_L1_{INST,DATA} as names for L1 cache descriptor types. Set descriptor 0x63 type as TLB_DATA_1G_2M_4M and explain why. Use enums for cache and TLB descriptor types (parent commits.) Start enum types at 1 since type 0 is reserved for unknown descriptors. Ensure that cache and TLB enum type values do not intersect. Add leaf 0x2 table accessor for_each_leaf_0x2_entry() + documentation. ] Co-developed-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-21-darwi@linutronix.de
2025-03-25x86/cpu: Use enums for TLB descriptor typesAhmed S. Darwish
The leaf 0x2 one-byte TLB descriptor types: TLB_INST_4K TLB_INST_4M TLB_INST_2M_4M ... are just discriminators to be used within the intel_tlb_table[] mapping. Their specific values are irrelevant. Use enums for such types. Make the enum packed and static assert that its values remain within a single byte so that the intel_tlb_table[] size do not go out of hand. Use a __CHECKER__ guard for the static_assert(sizeof(enum) == 1) line as sparse ignores the __packed annotation on enums. This is similar to: fe3944fb245a ("fs: Move enum rw_hint into a new header file") for the core SCSI code. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/Z9rsTirs9lLfEPD9@lx-t490 Link: https://lore.kernel.org/r/20250324133324.23458-20-darwi@linutronix.de
2025-03-25x86/cacheinfo: Use enums for cache descriptor typesAhmed S. Darwish
The leaf 0x2 one-byte cache descriptor types: CACHE_L1_INST CACHE_L1_DATA CACHE_L2 CACHE_L3 are just discriminators to be used within the cache_table[] mapping. Their specific values are irrelevant. Use enums for such types. Make the enum packed and static assert that its values remain within a single byte so that the cache_table[] array size do not go out of hand. Use a __CHECKER__ guard for the static_assert(sizeof(enum) == 1) line as sparse ignores the __packed annotation on enums. This is similar to: fe3944fb245a ("fs: Move enum rw_hint into a new header file") for the core SCSI code. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/Z9rsTirs9lLfEPD9@lx-t490 Link: https://lore.kernel.org/r/20250324133324.23458-19-darwi@linutronix.de
2025-03-25x86/cacheinfo: Clarify type markers for CPUID leaf 0x2 cache descriptorsAhmed S. Darwish
CPUID leaf 0x2 output is a stream of one-byte descriptors, each implying certain details about the CPU's cache and TLB entries. Two separate tables exist for interpreting these descriptors: one for TLBs at intel.c and one for caches at cacheinfo.c. These mapping tables will be merged in further commits, among other improvements to their model. In preparation for this, use more descriptive type names for the leaf 0x2 descriptors associated with cpu caches. Namely: LVL_1_INST => CACHE_L1_INST LVL_1_DATA => CACHE_L1_DATA LVL_2 => CACHE_L2 LVL_3 => CACHE_L3 After the TLB and cache descriptors mapping tables are merged, this will make it clear that such descriptors correspond to cpu caches. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-18-darwi@linutronix.de
2025-03-25x86/cacheinfo: Rename 'struct _cpuid4_info_regs' to 'struct _cpuid4_info'Ahmed S. Darwish
Parent commits decoupled amd_northbridge from _cpuid4_info_regs, moved AMD L3 northbridge cache_disable_0/1 sysfs code to its own file, and splitted AMD vs. Intel leaf 0x4 handling into: amd_fill_cpuid4_info() intel_fill_cpuid4_info() fill_cpuid4_info() After doing all that, the "_cpuid4_info_regs" name becomes a mouthful. It is also not totally accurate, as the structure holds cpuid4 derived information like cache node ID and size -- not just regs. Rename struct _cpuid4_info_regs to _cpuid4_info. That new name also better matches the AMD/Intel leaf 0x4 functions mentioned above. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-17-darwi@linutronix.de
2025-03-25x86/cacheinfo: Separate Intel and AMD CPUID leaf 0x4 code pathsAhmed S. Darwish
The CPUID leaf 0x4 parsing code at cpuid4_cache_lookup_regs() is ugly and convoluted. It is tangled with multiple nested conditions to handle: * AMD with TOPEXT, or Hygon CPUs via leaf 0x8000001d * Legacy AMD fallback via leaf 0x4 emulation * Intel CPUs via the actual CPUID leaf 0x4 Moreover, AMD L3 northbridge initialization is also awkwardly placed alongside the CPUID calls of the first two scenarios above. Refactor all of that as follows: * Update AMD's leaf 0x4 emulation comment to represent current state * Clearly label the AMD leaf 0x4 emulation function as a fallback * Split AMD/Hygon and Intel code paths into separate functions * Move AMD L3 northbridge initialization out of CPUID leaf 0x4 code, and into populate_cache_leaves() where it belongs. There, ci_info_init() can directly store the initialized object in the private pointer of the <linux/cacheinfo.h> API. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-16-darwi@linutronix.de
2025-03-25x86/cacheinfo: Use sysfs_emit() for sysfs attributes show()Ahmed S. Darwish
Per Documentation/filesystems/sysfs.rst, a sysfs attribute's show() method should only use sysfs_emit() or sysfs_emit_at() when returning values to user space. Use sysfs_emit() for the AMD L3 cache sysfs attributes cache_disable_0, cache_disable_1, and subcaches. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-15-darwi@linutronix.de
2025-03-25x86/cacheinfo: Move AMD cache_disable_0/1 handling to separate fileAhmed S. Darwish
Parent commit decoupled amd_northbridge out of _cpuid4_info_regs, where it was merely "parked" there until ci_info_init() can store it in the private pointer of the <linux/cacheinfo.h> API. Given that decoupling, move the AMD-specific L3 cache_disable_0/1 sysfs code from the generic (and already extremely convoluted) x86/cacheinfo code into its own file. Compile the file only if CONFIG_AMD_NB and CONFIG_SYSFS are both enabled, which mirrors the existing logic. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-14-darwi@linutronix.de
2025-03-25x86/cacheinfo: Separate amd_northbridge from _cpuid4_info_regsAhmed S. Darwish
'struct _cpuid4_info_regs' is meant to hold the CPUID leaf 0x4 output registers (EAX, EBX, and ECX), as well as derived information such as the cache node ID and size. It also contains a reference to amd_northbridge, which is there only to be "parked" until ci_info_init() can store it in the priv pointer of the <linux/cacheinfo.h> API. That priv pointer is then used by AMD-specific L3 cache_disable_0/1 sysfs attributes. Decouple amd_northbridge from _cpuid4_info_regs and pass it explicitly through the functions at x86/cacheinfo. Doing so clarifies when amd_northbridge is actually needed (AMD-only code) and when it is not (Intel-specific code). It also prepares for moving the AMD-specific L3 cache_disable_0/1 sysfs code into its own file in next commit. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-13-darwi@linutronix.de
2025-03-25x86/cacheinfo: Consolidate AMD/Hygon leaf 0x8000001d callsAhmed S. Darwish
While gathering CPU cache info, CPUID leaf 0x8000001d is invoked in two separate if blocks: one for Hygon CPUs and one for AMDs with topology extensions. After each invocation, amd_init_l3_cache() is called. Merge the two if blocks into a single condition, thus removing the duplicated code. Future commits will expand these if blocks, so combining them now is both cleaner and more maintainable. Note, while at it, remove a useless "better error?" comment that was within the same function since the 2005 commit e2cac78935ff ("[PATCH] x86_64: When running cpuid4 need to run on the correct CPU"). Note, as previously done at commit aec28d852ed2 ("x86/cpuid: Standardize on u32 in <asm/cpuid/api.h>"), standardize on using 'u32' and 'u8' types. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-12-darwi@linutronix.de
2025-03-25x86/cacheinfo: Standardize _cpuid4_info_regs instance namingAhmed S. Darwish
The cacheinfo code frequently uses the output registers from CPUID leaf 0x4. Such registers are cached in 'struct _cpuid4_info_regs', augmented with related information, and are then passed across functions. The naming of these _cpuid4_info_regs instances is confusing at best. Some instances are called "this_leaf", which is vague as "this" lacks context and "leaf" is overly generic given that other CPUID leaves are also processed within cacheinfo. Other _cpuid4_info_regs instances are just called "base", adding further ambiguity. Standardize on id4 for all instances. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-11-darwi@linutronix.de
2025-03-25x86/cacheinfo: Align ci_info_init() assignment expressionsAhmed S. Darwish
The ci_info_init() function initializes 10 members of a 'struct cacheinfo' instance using passed data from CPUID leaf 0x4. Such assignment expressions are difficult to read in their current form. Align them for clarity. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-10-darwi@linutronix.de
2025-03-25x86/cacheinfo: Constify _cpuid4_info_regs instancesAhmed S. Darwish
_cpuid4_info_regs instances are passed through a large number of functions at cacheinfo.c. For clarity, constify the instance parameters where _cpuid4_info_regs is only read from. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-9-darwi@linutronix.de
2025-03-25x86/cacheinfo: Use proper name for cacheinfo instancesThomas Gleixner
The cacheinfo structure defined at <include/linux/cacheinfo.h> is a generic cache info object representation. Calling its instances at x86 cacheinfo.c "leaf" confuses it with a CPUID leaf -- especially that multiple CPUID calls are already sprinkled across that file. Most of such instances also have a redundant "this_" prefix. Rename all of the cacheinfo "this_leaf" instances to just "ci". [ darwi: Move into separate commit and write commit log ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-8-darwi@linutronix.de
2025-03-25x86/cacheinfo: Properly name amd_cpuid4()'s first parameterThomas Gleixner
amd_cpuid4()'s first parameter, "leaf", is not a CPUID leaf as the name implies. Rather, it's an index emulating CPUID(4)'s subleaf semantics; i.e. an ID for the cache object currently enumerated. Rename that parameter to "index". Apply minor coding style fixes to the rest of the function as well. [ darwi: Move into a separate commit and write commit log. Use "index" instead of "subleaf" for amd_cpuid4() first param, as that's the name typically used at the whole of cacheinfo.c. ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-7-darwi@linutronix.de
2025-03-25x86/cacheinfo: Refactor CPUID leaf 0x2 cache descriptor lookupThomas Gleixner
Extract the cache descriptor lookup logic out of the leaf 0x2 parsing code and into a dedicated function. This disentangles such lookup from the deeply nested leaf 0x2 parsing loop. Remove the cache table termination entry, as it is no longer needed after the ARRAY_SIZE()-based lookup. [ darwi: Move refactoring logic into this separate commit + commit log. Remove the cache table termination entry. ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-6-darwi@linutronix.de
2025-03-25x86/cacheinfo: Use CPUID leaf 0x2 parsing helpersAhmed S. Darwish
Parent commit introduced CPUID leaf 0x2 parsing helpers at <asm/cpuid/leaf_0x2_api.h>. The new API allows sharing leaf 0x2's output validation and iteration logic across both intel.c and cacheinfo.c. Convert cacheinfo.c to that new API. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-5-darwi@linutronix.de
2025-03-25x86/cpu: Introduce and use CPUID leaf 0x2 parsing helpersAhmed S. Darwish
Introduce CPUID leaf 0x2 parsing helpers at <asm/cpuid/leaf_0x2_api.h>. This allows sharing the leaf 0x2's output validation and iteration logic across both x86/cpu intel.c and cacheinfo.c. Start by converting intel.c to the new API. Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-4-darwi@linutronix.de
2025-03-25x86/cacheinfo: Remove CPUID leaf 0x2 parsing loopAhmed S. Darwish
Leaf 0x2 output includes a "query count" byte where it was supposed to specify the number of repeated CPUID leaf 0x2 subleaf 0 queries needed to extract all of the CPU's cache and TLB descriptors. Per current Intel manuals, all CPUs supporting this leaf "will always" return an iteration count of 1. Remove the leaf 0x2 query loop and just query the hardware once. Note, as previously done at commit aec28d852ed2 ("x86/cpuid: Standardize on u32 in <asm/cpuid/api.h>"), standardize on using 'u32' and 'u8' types. Suggested-by: Ingo Molnar <mingo@kernel.org> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-3-darwi@linutronix.de
2025-03-25x86/cpu: Remove CPUID leaf 0x2 parsing loopAhmed S. Darwish
Leaf 0x2 output includes a "query count" byte where it was supposed to specify the number of repeated CPUID leaf 0x2 subleaf 0 queries needed to extract all of the CPU's cache and TLB descriptors. Per current Intel manuals, all CPUs supporting this leaf "will always" return an iteration count of 1. Remove the leaf 0x2 query loop and just query the hardware once. Note, as previously done in: aec28d852ed2 ("x86/cpuid: Standardize on u32 in <asm/cpuid/api.h>") standardize on using 'u32' and 'u8' types. Suggested-by: Ingo Molnar <mingo@kernel.org> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250324133324.23458-2-darwi@linutronix.de
2025-03-25x86/split_lock: Simplify reenablingMaksim Davydov
When split_lock_mitigate is disabled, each CPU needs its own delayed_work structure. They are used to reenable split lock detection after its disabling. But delayed_work structure must be correctly initialized after its allocation. Current implementation uses deferred initialization that makes the split lock handler code unclear. The code can be simplified a bit if the initialization is moved to the appropriate initcall. sld_setup() is called before setup_per_cpu_areas(), thus it can't be used for this purpose, so introduce an independent initcall for the initialization. [ mingo: Simplified the 'work' assignment line a bit more. ] Signed-off-by: Maksim Davydov <davydov-max@yandex-team.ru> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250325085807.171885-1-davydov-max@yandex-team.ru
2025-03-25x86/fpu: Update the outdated comment above fpstate_init_user()Chao Gao
fpu_init_fpstate_user() was removed in: commit 582b01b6ab27 ("x86/fpu: Remove old KVM FPU interface"). Update that comment to accurately reflect the current state regarding its callers. Signed-off-by: Chao Gao <chao.gao@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250324131931.2097905-1-chao.gao@intel.com
2025-03-25x86/early_printk: Add support for MMIO-based UARTsDenis Mukhin
During the bring-up of an x86 board, the kernel was crashing before reaching the platform's console driver because of a bug in the firmware, leaving no trace of the boot progress. The only available method to debug the kernel boot process was via the platform's MMIO-based UART, as the board lacked an I/O port-based UART, PCI UART, or functional video output. Then it turned out that earlyprintk= does not have a knob to configure the MMIO-mapped UART. Extend the early printk facility to support platform MMIO-based UARTs on x86 systems, enabling debugging during the system bring-up phase. The command line syntax to enable platform MMIO-based UART is: earlyprintk=mmio,membase[,{nocfg|baudrate}][,keep] Note, the change does not integrate MMIO-based UART support to: arch/x86/boot/early_serial_console.c Also, update kernel parameters documentation with the new syntax and add the missing 'nocfg' setting to the PCI serial cards description. Signed-off-by: Denis Mukhin <dmukhin@ford.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250324-earlyprintk-v3-1-aee7421dc469@ford.com
2025-03-25x86/dumpstack: Fix inaccurate unwinding from exception stacks due to ↵Jann Horn
misplaced assignment Commit: 2e4be0d011f2 ("x86/show_trace_log_lvl: Ensure stack pointer is aligned, again") was intended to ensure alignment of the stack pointer; but it also moved the initialization of the "stack" variable down into the loop header. This was likely intended as a no-op cleanup, since the commit message does not mention it; however, this caused a behavioral change because the value of "regs" is different between the two places. Originally, get_stack_pointer() used the regs provided by the caller; after that commit, get_stack_pointer() instead uses the regs at the top of the stack frame the unwinder is looking at. Often, there are no such regs at all, and "regs" is NULL, causing get_stack_pointer() to fall back to the task's current stack pointer, which is not what we want here, but probably happens to mostly work. Other times, the original regs will point to another regs frame - in that case, the linear guess unwind logic in show_trace_log_lvl() will start unwinding too far up the stack, causing the first frame found by the proper unwinder to never be visited, resulting in a stack trace consisting purely of guess lines. Fix it by moving the "stack = " assignment back where it belongs. Fixes: 2e4be0d011f2 ("x86/show_trace_log_lvl: Ensure stack pointer is aligned, again") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250325-2025-03-unwind-fixes-v1-2-acd774364768@google.com
2025-03-24Merge tag 'x86-cleanups-2025-03-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 cleanups from Ingo Molnar: "Miscellaneous x86 cleanups by Arnd Bergmann, Charles Han, Mirsad Todorovac, Randy Dunlap, Thorsten Blum and Zhang Kunbo" * tag 'x86-cleanups-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/coco: Replace 'static const cc_mask' with the newly introduced cc_get_mask() function x86/delay: Fix inconsistent whitespace selftests/x86/syscall: Fix coccinelle WARNING recommending the use of ARRAY_SIZE() x86/platform: Fix missing declaration of 'x86_apple_machine' x86/irq: Fix missing declaration of 'io_apic_irqs' x86/usercopy: Fix kernel-doc func param name in clean_cache_range()'s description x86/apic: Use str_disabled_enabled() helper in print_ipi_mode()
2025-03-24Merge tag 'x86-fpu-2025-03-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86/fpu updates from Ingo Molnar: - Improve crypto performance by making kernel-mode FPU reliably usable in softirqs ((Eric Biggers) - Fully optimize out WARN_ON_FPU() (Eric Biggers) - Initial steps to support Support Intel APX (Advanced Performance Extensions) (Chang S. Bae) - Fix KASAN for arch_dup_task_struct() (Benjamin Berg) - Refine and simplify the FPU magic number check during signal return (Chang S. Bae) - Fix inconsistencies in guest FPU xfeatures (Chao Gao, Stanislav Spassov) - selftests/x86/xstate: Introduce common code for testing extended states (Chang S. Bae) - Misc fixes and cleanups (Borislav Petkov, Colin Ian King, Uros Bizjak) * tag 'x86-fpu-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu/xstate: Fix inconsistencies in guest FPU xfeatures x86/fpu: Clarify the "xa" symbolic name used in the XSTATE* macros x86/fpu: Use XSAVE{,OPT,C,S} and XRSTOR{,S} mnemonics in xstate.h x86/fpu: Improve crypto performance by making kernel-mode FPU reliably usable in softirqs x86/fpu/xstate: Simplify print_xstate_features() x86/fpu: Refine and simplify the magic number check during signal return selftests/x86/xstate: Fix spelling mistake "hader" -> "header" x86/fpu: Avoid copying dynamic FP state from init_task in arch_dup_task_struct() vmlinux.lds.h: Remove entry to place init_task onto init_stack selftests/x86/avx: Add AVX tests selftests/x86/xstate: Clarify supported xstates selftests/x86/xstate: Consolidate test invocations into a single entry selftests/x86/xstate: Introduce signal ABI test selftests/x86/xstate: Refactor ptrace ABI test selftests/x86/xstate: Refactor context switching test selftests/x86/xstate: Enumerate and name xstate components selftests/x86/xstate: Refactor XSAVE helpers for general use selftests/x86: Consolidate redundant signal helper functions x86/fpu: Fix guest FPU state buffer allocation size x86/fpu: Fully optimize out WARN_ON_FPU()
2025-03-24Merge tag 'x86-boot-2025-03-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 boot code updates from Ingo Molnar: - Memblock setup and other early boot code cleanups (Mike Rapoport) - Export e820_table_kexec[] to sysfs (Dave Young) - Baby steps of adding relocate_kernel() debugging support (David Woodhouse) - Replace open-coded parity calculation with parity8() (Kuan-Wei Chiu) - Move the LA57 trampoline to separate source file (Ard Biesheuvel) - Misc micro-optimizations (Uros Bizjak) - Drop obsolete E820_TYPE_RESERVED_KERN and related code (Mike Rapoport) * tag 'x86-boot-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/kexec: Add relocate_kernel() debugging support: Load a GDT x86/boot: Move the LA57 trampoline to separate source file x86/boot: Do not test if AC and ID eflags are changeable on x86_64 x86/bootflag: Replace open-coded parity calculation with parity8() x86/bootflag: Micro-optimize sbf_write() x86/boot: Add missing has_cpuflag() prototype x86/kexec: Export e820_table_kexec[] to sysfs x86/boot: Change some static bootflag functions to bool x86/e820: Drop obsolete E820_TYPE_RESERVED_KERN and related code x86/boot: Split parsing of boot_params into the parse_boot_params() helper function x86/boot: Split kernel resources setup into the setup_kernel_resources() helper function x86/boot: Move setting of memblock parameters to e820__memblock_setup()
2025-03-24Merge tag 'x86-core-2025-03-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core x86 updates from Ingo Molnar: "x86 CPU features support: - Generate the <asm/cpufeaturemasks.h> header based on build config (H. Peter Anvin, Xin Li) - x86 CPUID parsing updates and fixes (Ahmed S. Darwish) - Introduce the 'setcpuid=' boot parameter (Brendan Jackman) - Enable modifying CPU bug flags with '{clear,set}puid=' (Brendan Jackman) - Utilize CPU-type for CPU matching (Pawan Gupta) - Warn about unmet CPU feature dependencies (Sohil Mehta) - Prepare for new Intel Family numbers (Sohil Mehta) Percpu code: - Standardize & reorganize the x86 percpu layout and related cleanups (Brian Gerst) - Convert the stackprotector canary to a regular percpu variable (Brian Gerst) - Add a percpu subsection for cache hot data (Brian Gerst) - Unify __pcpu_op{1,2}_N() macros to __pcpu_op_N() (Uros Bizjak) - Construct __percpu_seg_override from __percpu_seg (Uros Bizjak) MM: - Add support for broadcast TLB invalidation using AMD's INVLPGB instruction (Rik van Riel) - Rework ROX cache to avoid writable copy (Mike Rapoport) - PAT: restore large ROX pages after fragmentation (Kirill A. Shutemov, Mike Rapoport) - Make memremap(MEMREMAP_WB) map memory as encrypted by default (Kirill A. Shutemov) - Robustify page table initialization (Kirill A. Shutemov) - Fix flush_tlb_range() when used for zapping normal PMDs (Jann Horn) - Clear _PAGE_DIRTY for kernel mappings when we clear _PAGE_RW (Matthew Wilcox) KASLR: - x86/kaslr: Reduce KASLR entropy on most x86 systems, to support PCI BAR space beyond the 10TiB region (CONFIG_PCI_P2PDMA=y) (Balbir Singh) CPU bugs: - Implement FineIBT-BHI mitigation (Peter Zijlstra) - speculation: Simplify and make CALL_NOSPEC consistent (Pawan Gupta) - speculation: Add a conditional CS prefix to CALL_NOSPEC (Pawan Gupta) - RFDS: Exclude P-only parts from the RFDS affected list (Pawan Gupta) System calls: - Break up entry/common.c (Brian Gerst) - Move sysctls into arch/x86 (Joel Granados) Intel LAM support updates: (Maciej Wieczor-Retman) - selftests/lam: Move cpu_has_la57() to use cpuinfo flag - selftests/lam: Skip test if LAM is disabled - selftests/lam: Test get_user() LAM pointer handling AMD SMN access updates: - Add SMN offsets to exclusive region access (Mario Limonciello) - Add support for debugfs access to SMN registers (Mario Limonciello) - Have HSMP use SMN through AMD_NODE (Yazen Ghannam) Power management updates: (Patryk Wlazlyn) - Allow calling mwait_play_dead with an arbitrary hint - ACPI/processor_idle: Add FFH state handling - intel_idle: Provide the default enter_dead() handler - Eliminate mwait_play_dead_cpuid_hint() Build system: - Raise the minimum GCC version to 8.1 (Brian Gerst) - Raise the minimum LLVM version to 15.0.0 (Nathan Chancellor) Kconfig: (Arnd Bergmann) - Add cmpxchg8b support back to Geode CPUs - Drop 32-bit "bigsmp" machine support - Rework CONFIG_GENERIC_CPU compiler flags - Drop configuration options for early 64-bit CPUs - Remove CONFIG_HIGHMEM64G support - Drop CONFIG_SWIOTLB for PAE - Drop support for CONFIG_HIGHPTE - Document CONFIG_X86_INTEL_MID as 64-bit-only - Remove old STA2x11 support - Only allow CONFIG_EISA for 32-bit Headers: - Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI and non-UAPI headers (Thomas Huth) Assembly code & machine code patching: - x86/alternatives: Simplify alternative_call() interface (Josh Poimboeuf) - x86/alternatives: Simplify callthunk patching (Peter Zijlstra) - KVM: VMX: Use named operands in inline asm (Josh Poimboeuf) - x86/hyperv: Use named operands in inline asm (Josh Poimboeuf) - x86/traps: Cleanup and robustify decode_bug() (Peter Zijlstra) - x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h> (Uros Bizjak) - Use named operands in inline asm (Uros Bizjak) - Improve performance by using asm_inline() for atomic locking instructions (Uros Bizjak) Earlyprintk: - Harden early_serial (Peter Zijlstra) NMI handler: - Add an emergency handler in nmi_desc & use it in nmi_shootdown_cpus() (Waiman Long) Miscellaneous fixes and cleanups: - by Ahmed S. Darwish, Andy Shevchenko, Ard Biesheuvel, Artem Bityutskiy, Borislav Petkov, Brendan Jackman, Brian Gerst, Dan Carpenter, Dr. David Alan Gilbert, H. Peter Anvin, Ingo Molnar, Josh Poimboeuf, Kevin Brodsky, Mike Rapoport, Lukas Bulwahn, Maciej Wieczor-Retman, Max Grobecker, Patryk Wlazlyn, Pawan Gupta, Peter Zijlstra, Philip Redkin, Qasim Ijaz, Rik van Riel, Thomas Gleixner, Thorsten Blum, Tom Lendacky, Tony Luck, Uros Bizjak, Vitaly Kuznetsov, Xin Li, liuye" * tag 'x86-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (211 commits) zstd: Increase DYNAMIC_BMI2 GCC version cutoff from 4.8 to 11.0 to work around compiler segfault x86/asm: Make asm export of __ref_stack_chk_guard unconditional x86/mm: Only do broadcast flush from reclaim if pages were unmapped perf/x86/intel, x86/cpu: Replace Pentium 4 model checks with VFM ones perf/x86/intel, x86/cpu: Simplify Intel PMU initialization x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in non-UAPI headers x86/headers: Replace __ASSEMBLY__ with __ASSEMBLER__ in UAPI headers x86/locking/atomic: Improve performance by using asm_inline() for atomic locking instructions x86/asm: Use asm_inline() instead of asm() in clwb() x86/asm: Use CLFLUSHOPT and CLWB mnemonics in <asm/special_insns.h> x86/hweight: Use asm_inline() instead of asm() x86/hweight: Use ASM_CALL_CONSTRAINT in inline asm() x86/hweight: Use named operands in inline asm() x86/stackprotector/64: Only export __ref_stack_chk_guard on CONFIG_SMP x86/head/64: Avoid Clang < 17 stack protector in startup code x86/kexec: Merge x86_32 and x86_64 code using macros from <asm/asm.h> x86/runtime-const: Add the RUNTIME_CONST_PTR assembly macro x86/cpu/intel: Limit the non-architectural constant_tsc model checks x86/mm/pat: Replace Intel x86_model checks with VFM ones x86/cpu/intel: Fix fast string initialization for extended Families ...
2025-03-24Merge tag 'perf-core-2025-03-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull performance events updates from Ingo Molnar: "Core: - Move perf_event sysctls into kernel/events/ (Joel Granados) - Use POLLHUP for pinned events in error (Namhyung Kim) - Avoid the read if the count is already updated (Peter Zijlstra) - Allow the EPOLLRDNORM flag for poll (Tao Chen) - locking/percpu-rwsem: Add guard support [ NOTE: this got (mis-)merged into the perf tree due to related work ] (Peter Zijlstra) perf_pmu_unregister() related improvements: (Peter Zijlstra) - Simplify the perf_event_alloc() error path - Simplify the perf_pmu_register() error path - Simplify perf_pmu_register() - Simplify perf_init_event() - Simplify perf_event_alloc() - Merge struct pmu::pmu_disable_count into struct perf_cpu_pmu_context::pmu_disable_count - Add this_cpc() helper - Introduce perf_free_addr_filters() - Robustify perf_event_free_bpf_prog() - Simplify the perf_mmap() control flow - Further simplify perf_mmap() - Remove retry loop from perf_mmap() - Lift event->mmap_mutex in perf_mmap() - Detach 'struct perf_cpu_pmu_context' and 'struct pmu' lifetimes - Fix perf_mmap() failure path Uprobes: - Harden x86 uretprobe syscall trampoline check (Jiri Olsa) - Remove redundant spinlock in uprobe_deny_signal() (Liao Chang) - Remove the spinlock within handle_singlestep() (Liao Chang) x86 Intel PMU enhancements: - Support PEBS counters snapshotting (Kan Liang) - Fix intel_pmu_read_event() (Kan Liang) - Extend per event callchain limit to branch stack (Kan Liang) - Fix system-wide LBR profiling (Kan Liang) - Allocate bts_ctx only if necessary (Li RongQing) - Apply static call for drain_pebs (Peter Zijlstra) x86 AMD PMU enhancements: (Ravi Bangoria) - Remove pointless sample period check - Fix ->config to sample period calculation for OP PMU - Fix perf_ibs_op.cnt_mask for CurCnt - Don't allow freq mode event creation through ->config interface - Add PMU specific minimum period - Add ->check_period() callback - Ceil sample_period to min_period - Add support for OP Load Latency Filtering - Update DTLB/PageSize decode logic Hardware breakpoints: - Return EOPNOTSUPP for unsupported breakpoint type (Saket Kumar Bhaskar) Hardlockup detector improvements: (Li Huafei) - perf_event memory leak - Warn if watchdog_ev is leaked Fixes and cleanups: - Misc fixes and cleanups (Andy Shevchenko, Kan Liang, Peter Zijlstra, Ravi Bangoria, Thorsten Blum, XieLudan)" * tag 'perf-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (55 commits) perf: Fix __percpu annotation perf: Clean up pmu specific data perf/x86: Remove swap_task_ctx() perf/x86/lbr: Fix shorter LBRs call stacks for the system-wide mode perf: Supply task information to sched_task() perf: attach/detach PMU specific data locking/percpu-rwsem: Add guard support perf: Save PMU specific data in task_struct perf: Extend per event callchain limit to branch stack perf/ring_buffer: Allow the EPOLLRDNORM flag for poll perf/core: Use POLLHUP for pinned events in error perf/core: Use sysfs_emit() instead of scnprintf() perf/core: Remove optional 'size' arguments from strscpy() calls perf/x86/intel/bts: Check if bts_ctx is allocated when calling BTS functions uprobes/x86: Harden uretprobe syscall trampoline check watchdog/hardlockup/perf: Warn if watchdog_ev is leaked watchdog/hardlockup/perf: Fix perf_event memory leak perf/x86: Annotate struct bts_buffer::buf with __counted_by() perf/core: Clean up perf_try_init_event() perf/core: Fix perf_mmap() failure path ...
2025-03-24Merge tag 'sched-core-2025-03-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Core & fair scheduler changes: - Cancel the slice protection of the idle entity (Zihan Zhou) - Reduce the default slice to avoid tasks getting an extra tick (Zihan Zhou) - Force propagating min_slice of cfs_rq when {en,de}queue tasks (Tianchen Ding) - Refactor can_migrate_task() to elimate looping (I Hsin Cheng) - Add unlikey branch hints to several system calls (Colin Ian King) - Optimize current_clr_polling() on certain architectures (Yujun Dong) Deadline scheduler: (Juri Lelli) - Remove redundant dl_clear_root_domain call - Move dl_rebuild_rd_accounting to cpuset.h Uclamp: - Use the uclamp_is_used() helper instead of open-coding it (Xuewen Yan) - Optimize sched_uclamp_used static key enabling (Xuewen Yan) Scheduler topology support: (Juri Lelli) - Ignore special tasks when rebuilding domains - Add wrappers for sched_domains_mutex - Generalize unique visiting of root domains - Rebuild root domain accounting after every update - Remove partition_and_rebuild_sched_domains - Stop exposing partition_sched_domains_locked RSEQ: (Michael Jeanson) - Update kernel fields in lockstep with CONFIG_DEBUG_RSEQ=y - Fix segfault on registration when rseq_cs is non-zero - selftests: Add rseq syscall errors test - selftests: Ensure the rseq ABI TLS is actually 1024 bytes Membarriers: - Fix redundant load of membarrier_state (Nysal Jan K.A.) Scheduler debugging: - Introduce and use preempt_model_str() (Sebastian Andrzej Siewior) - Make CONFIG_SCHED_DEBUG unconditional (Ingo Molnar) Fixes and cleanups: - Always save/restore x86 TSC sched_clock() on suspend/resume (Guilherme G. Piccoli) - Misc fixes and cleanups (Thorsten Blum, Juri Lelli, Sebastian Andrzej Siewior)" * tag 'sched-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (40 commits) cpuidle, sched: Use smp_mb__after_atomic() in current_clr_polling() sched/debug: Remove CONFIG_SCHED_DEBUG sched/debug: Remove CONFIG_SCHED_DEBUG from self-test config files sched/debug, Documentation: Remove (most) CONFIG_SCHED_DEBUG references from documentation sched/debug: Make CONFIG_SCHED_DEBUG functionality unconditional sched/debug: Make 'const_debug' tunables unconditional __read_mostly sched/debug: Change SCHED_WARN_ON() to WARN_ON_ONCE() rseq/selftests: Fix namespace collision with rseq UAPI header include/{topology,cpuset}: Move dl_rebuild_rd_accounting to cpuset.h sched/topology: Stop exposing partition_sched_domains_locked cgroup/cpuset: Remove partition_and_rebuild_sched_domains sched/topology: Remove redundant dl_clear_root_domain call sched/deadline: Rebuild root domain accounting after every update sched/deadline: Generalize unique visiting of root domains sched/topology: Wrappers for sched_domains_mutex sched/deadline: Ignore special tasks when rebuilding domains tracing: Use preempt_model_str() xtensa: Rely on generic printing of preemption model x86: Rely on generic printing of preemption model s390: Rely on generic printing of preemption model ...
2025-03-24Merge tag 'objtool-core-2025-03-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Ingo Molnar: - The biggest change is the new option to automatically fail the build on objtool warnings: CONFIG_OBJTOOL_WERROR. While there are no currently known unfixed false positives left, such an expansion in the severity of objtool warnings inevitably creates a risk of build failures, so it's disabled by default and depends on !COMPILE_TEST, so it shouldn't be enabled on allyesconfig/allmodconfig builds and won't be forced on people who just accept build-time defaults in 'make oldconfig'. While the option is strongly recommended, only people who enable it explicitly should see it. (Josh Poimboeuf) - Disable branch profiling in noinstr code with a broad brush that includes all of arch/x86/ and kernel/sched/. (Josh Poimboeuf) - Create backup object files on objtool errors and print exact objtool arguments to make failure analysis easier (Josh Poimboeuf) - Improve noreturn handling (Josh Poimboeuf) - Improve rodata handling (Tiezhu Yang) - Support jump tables, switch tables and goto tables on LoongArch (Tiezhu Yang) - Misc cleanups and fixes (Josh Poimboeuf, David Engraf, Ingo Molnar) * tag 'objtool-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) tracing: Disable branch profiling in noinstr code objtool: Use O_CREAT with explicit mode mask objtool: Add CONFIG_OBJTOOL_WERROR objtool: Create backup on error and print args objtool: Change "warning:" to "error:" for --Werror objtool: Add --Werror option objtool: Add --output option objtool: Upgrade "Linked object detected" warning to error objtool: Consolidate option validation objtool: Remove --unret dependency on --rethunk objtool: Increase per-function WARN_FUNC() rate limit objtool: Update documentation objtool: Improve __noreturn annotation warning objtool: Fix error handling inconsistencies in check() x86/traps: Make exc_double_fault() consistently noreturn LoongArch: Enable jump table for objtool objtool/LoongArch: Add support for goto table objtool/LoongArch: Add support for switch table objtool: Handle PC relative relocation type objtool: Handle different entry size of rodata ...
2025-03-24Merge tag 'locking-core-2025-03-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "Locking primitives: - Micro-optimize percpu_{,try_}cmpxchg{64,128}_op() and {,try_}cmpxchg{64,128} on x86 (Uros Bizjak) - mutexes: extend debug checks in mutex_lock() (Yunhui Cui) - Misc cleanups (Uros Bizjak) Lockdep: - Fix might_fault() lockdep check of current->mm->mmap_lock (Peter Zijlstra) - Don't disable interrupts on RT in disable_irq_nosync_lockdep.*() (Sebastian Andrzej Siewior) - Disable KASAN instrumentation of lockdep.c (Waiman Long) - Add kasan_check_byte() check in lock_acquire() (Waiman Long) - Misc cleanups (Sebastian Andrzej Siewior) Rust runtime integration: - Use Pin for all LockClassKey usages (Mitchell Levy) - sync: Add accessor for the lock behind a given guard (Alice Ryhl) - sync: condvar: Add wait_interruptible_freezable() (Alice Ryhl) - sync: lock: Add an example for Guard:: Lock_ref() (Boqun Feng) Split-lock detection feature (x86): - Fix warning mode with disabled mitigation mode (Maksim Davydov) Locking events: - Add locking events for rtmutex slow paths (Waiman Long) - Add locking events for lockdep (Waiman Long)" * tag 'locking-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Remove disable_irq_lockdep() lockdep: Don't disable interrupts on RT in disable_irq_nosync_lockdep.*() rust: lockdep: Use Pin for all LockClassKey usages rust: sync: condvar: Add wait_interruptible_freezable() rust: sync: lock: Add an example for Guard:: Lock_ref() rust: sync: Add accessor for the lock behind a given guard locking/lockdep: Add kasan_check_byte() check in lock_acquire() locking/lockdep: Disable KASAN instrumentation of lockdep.c locking/lock_events: Add locking events for lockdep locking/lock_events: Add locking events for rtmutex slow paths x86/split_lock: Fix the delayed detection logic lockdep/mm: Fix might_fault() lockdep check of current->mm->mmap_lock x86/locking: Remove semicolon from "lock" prefix locking/mutex: Add MUTEX_WARN_ON() into fast path x86/locking: Use asm_inline for {,try_}cmpxchg{64,128} emulations x86/locking: Use ALT_OUTPUT_SP() for percpu_{,try_}cmpxchg{64,128}_op()
2025-03-24Merge branch 'pm-cpufreq'Rafael J. Wysocki
Merge cpufreq updates for 6.15-rc1: - Manage sysfs attributes and boost frequencies efficiently from cpufreq core to reduce boilerplate code from drivers (Viresh Kumar). - Minor cleanups to cpufreq drivers (Aaron Kling, Benjamin Schneider, Dhananjay Ugwekar, Imran Shaik, and zuoqian). - Migrate some cpufreq drivers to using for_each_present_cpu() (Jacky Bai). - cpufreq-qcom-hw DT binding fixes (Krzysztof Kozlowski). - Use str_enable_disable() helper in cpufreq_online() (Lifeng Zheng). - Optimize the amd-pstate driver to avoid cases where call paths end up calling the same writes multiple times and needlessly caching variables through code reorganization, locking overhaul and tracing adjustments (Mario Limonciello, Dhananjay Ugwekar). - Make it possible to avoid enabling capacity-aware scheduling (CAS) in the intel_pstate driver and relocate a check for out-of-band (OOB) platform handling in it to make it detect OOB before checking HWP availability (Rafael Wysocki). - Fix dbs_update() to avoid inadvertent conversions of negative integer values to unsigned int which causes CPU frequency selection to be inaccurate in some cases when the "conservative" cpufreq governor is in use (Jie Zhan). * pm-cpufreq: (91 commits) dt-bindings: cpufreq: cpufreq-qcom-hw: Narrow properties on SDX75, SA8775p and SM8650 dt-bindings: cpufreq: cpufreq-qcom-hw: Drop redundant minItems:1 dt-bindings: cpufreq: cpufreq-qcom-hw: Add missing constraint for interrupt-names dt-bindings: cpufreq: cpufreq-qcom-hw: Add QCS8300 compatible cpufreq: Init cpufreq only for present CPUs cpufreq: tegra186: Share policy per cluster cpufreq/amd-pstate: Drop actions in amd_pstate_epp_cpu_offline() cpufreq/amd-pstate: Stop caching EPP cpufreq/amd-pstate: Rework CPPC enabling cpufreq/amd-pstate: Drop debug statements for policy setting cpufreq/amd-pstate: Update cppc_req_cached for shared mem EPP writes cpufreq/amd-pstate: Move all EPP tracing into *_update_perf and *_set_epp functions cpufreq/amd-pstate: Cache CPPC request in shared mem case too cpufreq/amd-pstate: Replace all AMD_CPPC_* macros with masks cpufreq/amd-pstate-ut: Adjust variable scope cpufreq/amd-pstate-ut: Run on all of the correct CPUs cpufreq/amd-pstate-ut: Drop SUCCESS and FAIL enums cpufreq/amd-pstate-ut: Allow lowest nonlinear and lowest to be the same cpufreq/amd-pstate-ut: Use _free macro to free put policy cpufreq/amd-pstate: Drop `cppc_cap1_cached` ...
2025-03-24Merge branches 'acpi-x86', 'acpi-platform-profile', 'acpi-apei' and 'acpi-misc'Rafael J. Wysocki
Merge an ACPI CPPC update, ACPI platform-profile driver updates, an ACPI APEI update and a MAINTAINERS update related to ACPI for 6.15-rc1: - Add a missing header file include to the x86 arch CPPC code (Mario Limonciello). - Rework the sysfs attributes implementation in the ACPI platform-profile driver and improve the unregistration code in it (Nathan Chancellor, Kurt Borja). - Prevent the ACPI HED driver from being built as a module and change its initcall level to subsys_initcall to avoid initialization ordering issues related to it (Xiaofei Tan). - Update a maintainer email address in the ACPI PMIC entry in MAINTAINERS (Mika Westerberg). * acpi-x86: x86/ACPI: CPPC: Add missing include * acpi-platform-profile: ACPI: platform_profile: Improve platform_profile_unregister() ACPI: platform-profile: Fix CFI violation when accessing sysfs files * acpi-apei: ACPI: HED: Always initialize before evged * acpi-misc: MAINTAINERS: Use my kernel.org address for ACPI PMIC work
2025-03-22tracing: Disable branch profiling in noinstr codeJosh Poimboeuf
CONFIG_TRACE_BRANCH_PROFILING inserts a call to ftrace_likely_update() for each use of likely() or unlikely(). That breaks noinstr rules if the affected function is annotated as noinstr. Disable branch profiling for files with noinstr functions. In addition to some individual files, this also includes the entire arch/x86 subtree, as well as the kernel/entry, drivers/cpuidle, and drivers/idle directories, all of which are noinstr-heavy. Due to the nature of how sched binaries are built by combining multiple .c files into one, branch profiling is disabled more broadly across the sched code than would otherwise be needed. This fixes many warnings like the following: vmlinux.o: warning: objtool: do_syscall_64+0x40: call to ftrace_likely_update() leaves .noinstr.text section vmlinux.o: warning: objtool: __rdgsbase_inactive+0x33: call to ftrace_likely_update() leaves .noinstr.text section vmlinux.o: warning: objtool: handle_bug.isra.0+0x198: call to ftrace_likely_update() leaves .noinstr.text section ... Reported-by: Ingo Molnar <mingo@kernel.org> Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/fb94fc9303d48a5ed370498f54500cc4c338eb6d.1742586676.git.jpoimboe@kernel.org
2025-03-20x86: hyperv: Add mshv_handler() irq handler and setup functionNuno Das Neves
Add mshv_handler() to process messages related to managing guest partitions such as intercepts, doorbells, and scheduling messages. In a (non-nested) root partition, the same interrupt vector is shared between the vmbus and mshv_root drivers. Introduce a stub for mshv_handler() and call it in sysvec_hyperv_callback alongside vmbus_handler(). Even though both handlers will be called for every Hyper-V interrupt, the messages for each driver are delivered to different offsets within the SYNIC message page, so they won't step on each other. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-9-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-9-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20Drivers: hv: Export some functions for use by root partition moduleNuno Das Neves
hv_get_hypervisor_version(), hv_call_deposit_pages(), and hv_call_create_vp(), are all needed in-module with CONFIG_MSHV_ROOT=m. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Stanislav Kinsburskii <skinsburskii@microsoft.linux.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Link: https://lore.kernel.org/r/1741980536-3865-7-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-7-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-20x86/mshyperv: Add support for extended Hyper-V featuresStanislav Kinsburskii
Extend the "ms_hyperv_info" structure to include a new field, "ext_features", for capturing extended Hyper-V features. Update the "ms_hyperv_init_platform" function to retrieve these features using the cpuid instruction and include them in the informational output. Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com> Reviewed-by: Roman Kisel <romank@linux.microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/1741980536-3865-3-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <1741980536-3865-3-git-send-email-nunodasneves@linux.microsoft.com>
2025-03-19x86/cpu/intel: Limit the non-architectural constant_tsc model checksSohil Mehta
X86_FEATURE_CONSTANT_TSC is a Linux-defined, synthesized feature flag. It is used across several vendors. Intel CPUs will set the feature when the architectural CPUID.80000007.EDX[1] bit is set. There are also some Intel CPUs that have the X86_FEATURE_CONSTANT_TSC behavior but don't enumerate it with the architectural bit. Those currently have a model range check. Today, virtually all of the CPUs that have the CPUID bit *also* match the "model >= 0x0e" check. This is confusing. Instead of an open-ended check, pick some models (INTEL_IVYBRIDGE and P4_WILLAMETTE) as the end of goofy CPUs that should enumerate the bit but don't. These models are relatively arbitrary but conservative pick for this. This makes it obvious that later CPUs (like Family 18+) no longer need to synthesize X86_FEATURE_CONSTANT_TSC. Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20250219184133.816753-14-sohil.mehta@intel.com
2025-03-19x86/cpu/intel: Fix fast string initialization for extended FamiliesSohil Mehta
X86_FEATURE_REP_GOOD is a linux defined feature flag to track whether fast string operations should be used for copy_page(). It is also used as a second alternative for clear_page() if enhanced fast string operations (ERMS) are not available. X86_FEATURE_ERMS is an Intel-specific hardware-defined feature flag that tracks hardware support for Enhanced Fast strings. It is used to track whether Fast strings should be used for similar memory copy and memory clearing operations. On top of these, there is a FAST_STRING enable bit in the IA32_MISC_ENABLE MSR. It is typically controlled by the BIOS to provide a hint to the hardware and the OS on whether fast string operations are preferred. Commit: 161ec53c702c ("x86, mem, intel: Initialize Enhanced REP MOVSB/STOSB") introduced a mechanism to honor the BIOS preference for fast string operations and clear the above feature flags if needed. Unfortunately, the current initialization code for Intel to set and clear these bits is confusing at best and likely incorrect. X86_FEATURE_REP_GOOD is cleared in early_init_intel() if MISC_ENABLE.FAST_STRING is 0. But it gets set later on unconditionally for all Family 6 processors in init_intel(). This not only overrides the BIOS preference but also contradicts the earlier check. Fix this by combining the related checks and always relying on the BIOS provided preference for fast string operations. This simplification makes sure the upcoming Intel Family 18 and 19 models are covered as well. Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Juergen Gross <jgross@suse.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250219184133.816753-12-sohil.mehta@intel.com
2025-03-19x86/smpboot: Fix INIT delay assignment for extended Intel FamiliesSohil Mehta
Some old crusty CPUs need an extra delay that slows down booting. See the comment above 'init_udelay' for details. Newer CPUs don't need the delay. Right now, for Intel, Family 6 and only Family 6 skips the delay. That leaves out both the Family 15 (Pentium 4s) and brand new Family 18/19 models. The omission of Family 15 (Pentium 4s) seems like an oversight and 18/19 do not need the delay. Skip the delay on all Intel processors Family 6 and beyond. Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250219184133.816753-11-sohil.mehta@intel.com
2025-03-19x86/smpboot: Remove confusing quirk usage in INIT delaySohil Mehta
Very old multiprocessor systems required a 10 msec delay between asserting and de-asserting INIT but modern processors do not require this delay. Over time the usage of the "quirk" wording while setting the INIT delay has become misleading. The code comments suggest that modern processors need to be quirked, which clears the default init_udelay of 10 msec, while legacy processors don't need the quirk and continue to use the default init_udelay. With a lot more modern processors, the wording should be inverted if at all needed. Instead, simplify the comments and the code by getting rid of "quirk" usage altogether and clarifying the following: - Old legacy processors -> Set the "legacy" 10 msec delay - Modern processors -> Do not set any delay No functional change. Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250219184133.816753-10-sohil.mehta@intel.com
2025-03-19x86/acpi/cstate: Improve Intel Family model checksSohil Mehta
Update the Intel Family checks to consistently use Family 15 instead of Family 0xF. Also, get rid of one of last usages of x86_model by using the new VFM checks. Update the incorrect comment since the check has changed since the initial commit: ee1ca48fae7e ("ACPI: Disable ARB_DISABLE on platforms where it is not needed") The two changes were: - 3e2ada5867b7 ("ACPI: fix Compaq Evo N800c (Pentium 4m) boot hang regression") removed the P4 - Family 15. - 03a05ed11529 ("ACPI: Use the ARB_DISABLE for the CPU which model id is less than 0x0f.") got rid of CORE_YONAH - Family 6, model E. Signed-off-by: Sohil Mehta <sohil.mehta@intel.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Link: https://lore.kernel.org/r/20250219184133.816753-9-sohil.mehta@intel.com