kernel/linux.git/arch/arm64/include, branch v6.12.94

arm64: cputype: Add C1-Premium definitions

2026-06-19T11:42:38+00:00

commit d28413bfc5a255957241f1df5d7fd0c2cd74fe18 upstream. Add cputype definitions for C1-Premium. These will be used for errata detection in subsequent patches. These values can be found in the C1-Premium TRM: https://developer.arm.com/documentation/109416/0100/ ... in section A.5.1 ("MIDR_EL1, Main ID Register"). Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Will Deacon [Mark: backport to v6.12.y] Signed-off-by: Mark Rutland Signed-off-by: Greg Kroah-Hartman

arm64: cputype: Add C1-Ultra definitions

2026-06-19T11:42:38+00:00

commit 60349e64a6c65f9f0aa118af711b3c7e137f07ff upstream. Add cputype definitions for C1-Ultra. These will be used for errata detection in subsequent patches. These values can be found in the C1-Ultra TRM: https://developer.arm.com/documentation/108014/0100/ ... in section A.5.1 ("MIDR_EL1, Main ID Register"). Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Will Deacon [Mark: backport to v6.12.y] Signed-off-by: Mark Rutland Signed-off-by: Greg Kroah-Hartman

arm64: cputype: Add NVIDIA Olympus definitions

2026-06-19T11:42:38+00:00

commit e185c8a0d84236d14af61faff8147c953a878a77 upstream. Add cpu part and model macro definitions for NVIDIA Olympus core. Signed-off-by: Shanker Donthineni Signed-off-by: Will Deacon [Mark: backport to v6.12.y] Signed-off-by: Mark Rutland Signed-off-by: Greg Kroah-Hartman

arm64: tlb: Optimize ARM64_WORKAROUND_REPEAT_TLBI

2026-06-19T11:42:23+00:00

commit a8f78680ee6bf795086384e8aea159a52814f827 upstream. The ARM64_WORKAROUND_REPEAT_TLBI workaround is used to mitigate several errata where broadcast TLBI;DSB sequences don't provide all the architecturally required synchronization. The workaround performs more work than necessary, and can have significant overhead. This patch optimizes the workaround, as explained below. The workaround was originally added for Qualcomm Falkor erratum 1009 in commit: d9ff80f83ecb ("arm64: Work around Falkor erratum 1009") As noted in the message for that commit, the workaround is applied even in cases where it is not strictly necessary. The workaround was later reused without changes for: * Arm Cortex-A76 erratum #1286807 SDEN v33: https://developer.arm.com/documentation/SDEN-885749/33-0/ * Arm Cortex-A55 erratum #2441007 SDEN v16: https://developer.arm.com/documentation/SDEN-859338/1600/ * Arm Cortex-A510 erratum #2441009 SDEN v19: https://developer.arm.com/documentation/SDEN-1873351/1900/ The important details to note are as follows: 1. All relevant errata only affect the ordering and/or completion of memory accesses which have been translated by an invalidated TLB entry. The actual invalidation of TLB entries is unaffected. 2. The existing workaround is applied to both broadcast and local TLB invalidation, whereas for all relevant errata it is only necessary to apply a workaround for broadcast invalidation. 3. The existing workaround replaces every TLBI with a TLBI;DSB;TLBI sequence, whereas for all relevant errata it is only necessary to execute a single additional TLBI;DSB sequence after any number of TLBIs are completed by a DSB. For example, for a sequence of batched TLBIs: TLBI [, ] TLBI [, ] TLBI [, ] DSB ISH ... the existing workaround will expand this to: TLBI [, ] DSB ISH // additional TLBI [, ] // additional TLBI [, ] DSB ISH // additional TLBI [, ] // additional TLBI [, ] DSB ISH // additional TLBI [, ] // additional DSB ISH ... whereas it is sufficient to have: TLBI [, ] TLBI [, ] TLBI [, ] DSB ISH TLBI [, ] // additional DSB ISH // additional Using a single additional TBLI and DSB at the end of the sequence can have significantly lower overhead as each DSB which completes a TLBI must synchronize with other PEs in the system, with potential performance effects both locally and system-wide. 4. The existing workaround repeats each specific TLBI operation, whereas for all relevant errata it is sufficient for the additional TLBI to use *any* operation which will be broadcast, regardless of which translation regime or stage of translation the operation applies to. For example, for a single TLBI: TLBI ALLE2IS DSB ISH ... the existing workaround will expand this to: TLBI ALLE2IS DSB ISH TLBI ALLE2IS // additional DSB ISH // additional ... whereas it is sufficient to have: TLBI ALLE2IS DSB ISH TLBI VALE1IS, XZR // additional DSB ISH // additional As the additional TLBI doesn't have to match a specific earlier TLBI, the additional TLBI can be implemented in separate code, with no memory of the earlier TLBIs. The additional TLBI can also use a cheaper TLBI operation. 5. The existing workaround is applied to both Stage-1 and Stage-2 TLB invalidation, whereas for all relevant errata it is only necessary to apply a workaround for Stage-1 invalidation. Architecturally, TLBI operations which invalidate only Stage-2 information (e.g. IPAS2E1IS) are not required to invalidate TLB entries which combine information from Stage-1 and Stage-2 translation table entries, and consequently may not complete memory accesses translated by those combined entries. In these cases, completion of memory accesses is only guaranteed after subsequent invalidation of Stage-1 information (e.g. VMALLE1IS). Taking the above points into account, this patch reworks the workaround logic to reduce overhead: * New __tlbi_sync_s1ish() and __tlbi_sync_s1ish_hyp() functions are added and used in place of any dsb(ish) which is used to complete broadcast Stage-1 TLB maintenance. When the ARM64_WORKAROUND_REPEAT_TLBI workaround is enabled, these helpers will execute an additional TLBI;DSB sequence. For consistency, it might make sense to add __tlbi_sync_*() helpers for local and stage 2 maintenance. For now I've left those with open-coded dsb() to keep the diff small. * The duplication of TLBIs in __TLBI_0() and __TLBI_1() is removed. This is no longer needed as the necessary synchronization will happen in __tlbi_sync_s1ish() or __tlbi_sync_s1ish_hyp(). * The additional TLBI operation is chosen to have minimal impact: - __tlbi_sync_s1ish() uses "TLBI VALE1IS, XZR". This is only used at EL1 or at EL2 with {E2H,TGE}=={1,1}, where it will target an unused entry for the reserved ASID in the kernel's own translation regime, and have no adverse affect. - __tlbi_sync_s1ish_hyp() uses "TLBI VALE2IS, XZR". This is only used in hyp code, where it will target an unused entry in the hyp code's TTBR0 mapping, and should have no adverse effect. * As __TLBI_0() and __TLBI_1() no longer replace each TLBI with a TLBI;DSB;TLBI sequence, batching TLBIs is worthwhile, and there's no need for arch_tlbbatch_should_defer() to consider ARM64_WORKAROUND_REPEAT_TLBI. When building defconfig with GCC 15.1.0, compared to v6.19-rc1, this patch saves ~1KiB of text, makes the vmlinux ~42KiB smaller, and makes the resulting Image 64KiB smaller: | [mark@lakrids:~/src/linux]% size vmlinux-* | text data bss dec hex filename | 21179831 19660919 708216 41548966 279fca6 vmlinux-after | 21181075 19660903 708216 41550194 27a0172 vmlinux-before | [mark@lakrids:~/src/linux]% ls -l vmlinux-* | -rwxr-xr-x 1 mark mark 157771472 Feb 4 12:05 vmlinux-after | -rwxr-xr-x 1 mark mark 157815432 Feb 4 12:05 vmlinux-before | [mark@lakrids:~/src/linux]% ls -l Image-* | -rw-r--r-- 1 mark mark 41007616 Feb 4 12:05 Image-after | -rw-r--r-- 1 mark mark 41073152 Feb 4 12:05 Image-before Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Marc Zyngier Cc: Oliver Upton Cc: Ryan Roberts Cc: Will Deacon Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman [Mark: Backport to v6.12.y] Signed-off-by: Mark Rutland Signed-off-by: Sasha Levin

arm64: tlb: Allow XZR argument to TLBI ops

2026-06-19T11:42:23+00:00

commit bfd9c931d19aa59fb8371d557774fa169b15db9a upstream. The TLBI instruction accepts XZR as a register argument, and for TLBI operations with a register argument, there is no functional difference between using XZR or another GPR which contains zeroes. Operations without a register argument are encoded as if XZR were used. Allow the __TLBI_1() macro to use XZR when a register argument is all zeroes. Today this only results in a trivial code saving in __do_compat_cache_op()'s workaround for Neoverse-N1 erratum #1542419. In subsequent patches this pattern will be used more generally. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Marc Zyngier Cc: Oliver Upton Cc: Ryan Roberts Cc: Will Deacon Signed-off-by: Will Deacon Signed-off-by: Catalin Marinas Signed-off-by: Greg Kroah-Hartman [Mark: Backport to v6.12.y] Signed-off-by: Mark Rutland Signed-off-by: Sasha Levin

arm64: tlb: Flush walk cache when unsharing PMD tables

2026-06-09T10:26:03+00:00

[ Upstream commit c2ff4764e03e7a8d758352f4aceb8fe1be6ac971 ] When huge_pmd_unshare() is called to unshare a PMD table, the tlb_unshare_pmd_ptdesc() function sets tlb->unshared_tables=true but the aarch64 tlb_flush() only checked tlb->freed_tables to determine whether to use TLBF_NONE (vae1is, invalidates walk cache) or TLBF_NOWALKCACHE (vale1is, leaf-only). This caused the stale PMD page table entry to remain in the walk cache after unshare, potentially leading to incorrect page table walks. Fix by including unshared_tables in the check, so that when unsharing tables, TLBF_NONE is used and the walk cache is properly invalidated. Here is the detailed distinction between vae1is and vale1is: | Instruction Combination | Actual Invalidation Scope | | ------------------------ | --------------------------------------------------| | `VAE1IS` + TTL=`0` | All entries at all levels (full invalidation) | | `VAE1IS` + TTL=`2` (L2) | Non-leaf at Level 0/1 + leaf at Level 2 | | `VALE1IS` + TTL=`0` | Leaf entries at all levels (non-leaf not cleared) | | `VALE1IS` + TTL=`2` (L2) | Leaf entry at Level 2 only | Signed-off-by: Zeng Heng Fixes: 8ce720d5bd91 ("mm/hugetlb: fix excessive IPI broadcasts when unsharing PMD tables using mmu_gather") Cc: Signed-off-by: Catalin Marinas Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ring-buffer: Flush and stop persistent ring buffer on panic

2026-06-09T10:26:03+00:00

[ Upstream commit a494d3c8d5392bcdff83c2a593df0c160ff9f322 ] On real hardware, panic and machine reboot may not flush hardware cache to memory. This means the persistent ring buffer, which relies on a coherent state of memory, may not have its events written to the buffer and they may be lost. Moreover, there may be inconsistency with the counters which are used for validation of the integrity of the persistent ring buffer which may cause all data to be discarded. To avoid this issue, stop recording of the ring buffer on panic and flush the cache of the ring buffer's memory. Fixes: e645535a954a ("tracing: Add option to use memmapped memory for trace boot instance") Cc: stable@vger.kernel.org Cc: Will Deacon Cc: Mathieu Desnoyers Cc: Ian Rogers Link: https://patch.msgid.link/177751969602.2136606.12031934362587643488.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) Acked-by: Catalin Marinas Acked-by: Geert Uytterhoeven Signed-off-by: Steven Rostedt Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

arm64: io: Extract user memory type in ioremap_prot()

2026-06-09T10:25:47+00:00

[ Upstream commit 8f098037139b294050053123ab2bc0f819d08932 ] The only caller of ioremap_prot() outside of the generic ioremap() implementation is generic_access_phys(), which passes a 'pgprot_t' value determined from the user mapping of the target 'pfn' being accessed by the kernel. On arm64, the 'pgprot_t' contains all of the non-address bits from the pte, including the permission controls, and so we end up returning a new user mapping from ioremap_prot() which faults when accessed from the kernel on systems with PAN: | Unable to handle kernel read from unreadable memory at virtual address ffff80008ea89000 | ... | Call trace: | __memcpy_fromio+0x80/0xf8 | generic_access_phys+0x20c/0x2b8 | __access_remote_vm+0x46c/0x5b8 | access_remote_vm+0x18/0x30 | environ_read+0x238/0x3e8 | vfs_read+0xe4/0x2b0 | ksys_read+0xcc/0x178 | __arm64_sys_read+0x4c/0x68 Extract only the memory type from the user 'pgprot_t' in ioremap_prot() and assert that we're being passed a user mapping, to protect us against any changes in future that may require additional handling. To avoid falsely flagging users of ioremap(), provide our own ioremap() macro which simply wraps __ioremap_prot(). Cc: Zeng Heng Cc: Jinjiang Tu Cc: Catalin Marinas Fixes: 893dea9ccd08 ("arm64: Add HAVE_IOREMAP_PROT support") Reported-by: Jinjiang Tu Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon [ Modified ioremap_prot() parameter, using "unsigned long user_prot" instead of "pgprot_t user_prot" to fix conflict with generic header ] Signed-off-by: Xiangyu Chen Signed-off-by: Sasha Levin

arm64: io: Rename ioremap_prot() to __ioremap_prot()

2026-06-09T10:25:47+00:00

commit f6bf47ab32e0863df50f5501d207dcdddb7fc507 upstream. Rename our ioremap_prot() implementation to __ioremap_prot() and convert all arch-internal callers over to the new function. ioremap_prot() remains as a #define to __ioremap_prot() for generic_access_phys() and will be subsequently extended to handle user permissions in 'prot'. Cc: Zeng Heng Cc: Jinjiang Tu Cc: Catalin Marinas Reviewed-by: Catalin Marinas Signed-off-by: Will Deacon Signed-off-by: Xiangyu Chen Signed-off-by: Sasha Levin

arm64: debug: remove debug exception registration infrastructure

2026-06-09T10:25:37+00:00

[ Upstream commit a8b8cce9d96d65dfe3d89abf02033151f8b7d670 ] Now that debug exceptions are handled individually and without the need for dynamic registration, remove the unused registration infrastructure. This removes the external caller for `debug_exception_enter()` and `debug_exception_exit()`. Make them static again and remove them from the header. Remove `early_brk64()` as it has been made redundant by (arm64: debug: split brk64 exception entry) and is not used anymore. Note : in `early_brk64()` `bug_brk_handler()` is called unconditionally as a fall-through, but now `call_break_hook()` only calls it if the immediate matches. This does not change the behaviour in early boot, as if `bug_brk_handler()` was called on a non-BUG immediate it would return DBG_HOOK_ERROR anyway, which `call_break_hook()` will do if no immediate matches. Remove `trap_init()`, as it would be empty and a weak definition already exists in `init/main.c`. Signed-off-by: Ada Couprie Diaz Tested-by: Luis Claudio R. Goncalves Reviewed-by: Will Deacon Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20250707114109.35672-14-ada.coupriediaz@arm.com Signed-off-by: Will Deacon Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Ada Couprie Diaz Signed-off-by: Sasha Levin