[PATCH RFC 04/17] arm64: make clean_dcache_range_nopatch() visible

Russell King (Oracle) rmk+kernel at armlinux.org.uk
Tue May 30 07:04:50 PDT 2023


When we hook into the kernel text patching code, we will need to call
clean_dcache_range_nopatch() to ensure that the patching of the
replicated kernel text is properly visible to other CPUs. Make this
function available to the replication code.

Signed-off-by: Russell King (Oracle) <rmk+kernel at armlinux.org.uk>
---
 arch/arm64/include/asm/cacheflush.h | 2 ++
 arch/arm64/kernel/alternative.c     | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/cacheflush.h b/arch/arm64/include/asm/cacheflush.h
index 37185e978aeb..ac9ad56d5212 100644
--- a/arch/arm64/include/asm/cacheflush.h
+++ b/arch/arm64/include/asm/cacheflush.h
@@ -104,6 +104,8 @@ static inline void flush_icache_range(unsigned long start, unsigned long end)
 }
 #define flush_icache_range flush_icache_range
 
+void clean_dcache_range_nopatch(u64 start, u64 end);
+
 /*
  * Copy user data from/to a page which is mapped into a different
  * processes address space.  Really, we want to allow our "user
diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c
index d32d4ed5519b..df9a73458a85 100644
--- a/arch/arm64/kernel/alternative.c
+++ b/arch/arm64/kernel/alternative.c
@@ -121,7 +121,7 @@ static noinstr void patch_alternative(struct alt_instr *alt,
  * accidentally call into the cache.S code, which is patched by us at
  * runtime.
  */
-static void clean_dcache_range_nopatch(u64 start, u64 end)
+void clean_dcache_range_nopatch(u64 start, u64 end)
 {
 	u64 cur, d_size, ctr_el0;
 
-- 
2.30.2




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