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2026-05-23openrisc: Fix jump_label smp syncingStafford Horne
The original commit 8c30b0018f9d ("openrisc: Add jump label support") copies from arm64 and does not properly consider how icache invalidation on remote cores works in OpenRISC. On OpenRISC remote icaches need to be invalidated otherwise static key's may remain state after updating. Fix SMP cache syncing by: 1. Properly invalidate remote core icaches on SMP systems by using icache_all_inv. The old code uses kick_all_cpus_sync() which runs a no-op IPI function call on remote CPU's which does execute a lot of code and flushes many cache lines in the process, but does not flush all and it's not correct on OpenRISC. 2. For architectures that do not have WRITETHROUGH caches be sure to flush the dcache after patching. To test this I first reproduced the issue using a custom test module [0]. The test confirmed that some icache lines maintained stale static_key code sequences after calling static_branch_enable(). After this patch there are no longer jump_label coherency issues. [0] https://github.com/stffrdhrn/or1k-utils/tree/master/tests/smp_static_key_test Cc: stable@vger.kernel.org # depends on openrisc: Add icache_all_inv Fixes: 8c30b0018f9d ("openrisc: Add jump label support") Signed-off-by: Stafford Horne <shorne@gmail.com>
2025-09-11openrisc: Add text patching API supportchenmiao
Add text patching api's to use in subsequent jump_label implementation. We use a new fixmap FIX_TEXT_POKE0 entry to temporarily override MMU mappings to allow read only text pages to be written to. Previously, __set_fix was marked with __init as it was only used during the EARLYCON stage. Now that TEXT_POKE mappings require post-init usage (e.g., FIX_TEXT_POKE0), keeping __init would cause runtime bugs whenset_fixmap accesses invalid memory. Thus, we remove the __init flag to ensure __set_fix remains valid beyond initialization. A new function patch_insn_write is exposed to allow single instruction patching. Link: https://lore.kernel.org/openrisc/aJIC8o1WmVHol9RY@antec/T/#t Signed-off-by: chenmiao <chenmiao.ku@gmail.com> Signed-off-by: Stafford Horne <shorne@gmail.com>