[PATCH v4 07/22] arm: cache: keep range maintenance available at EFI runtime

The FF-A EFI runtime variable path uses a shared MM communication buffer
after ExitBootServices(). Before sending a request to the MM secure
partition the buffer range must be flushed, and after the response the
same range must be invalidated.

Keep flush_dcache_range() and invalidate_dcache_range() available from
EFI runtime code on arm64, together with the underlying assembly range
helpers, so the FF-A runtime transport can maintain the shared buffer
without using whole-cache operations after ExitBootServices().

Reviewed-by: Simon Glass <[email protected]>
Signed-off-by: Harsimran Singh Tungal <[email protected]>
---
 arch/arm/cpu/armv8/cache.S    |  8 ++++++++
 arch/arm/cpu/armv8/cache_v8.c | 13 +++++++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/arch/arm/cpu/armv8/cache.S b/arch/arm/cpu/armv8/cache.S
index c9e46859b4f..916558fe477 100644
--- a/arch/arm/cpu/armv8/cache.S
+++ b/arch/arm/cpu/armv8/cache.S
@@ -169,7 +169,11 @@ ENDPROC(__asm_flush_l3_dcache)
  * x0: start address
  * x1: end address
  */
+#ifdef CONFIG_EFI_LOADER
+.pushsection .text.efi_runtime.__asm_flush_dcache_range, "ax"
+#else
 .pushsection .text.__asm_flush_dcache_range, "ax"
+#endif
 ENTRY(__asm_flush_dcache_range)
 	mrs	x3, ctr_el0
 	ubfx	x3, x3, #16, #4
@@ -195,7 +199,11 @@ ENDPROC(__asm_flush_dcache_range)
  * x0: start address
  * x1: end address
  */
+#ifdef CONFIG_EFI_LOADER
+.pushsection .text.efi_runtime.__asm_invalidate_dcache_range, "ax"
+#else
 .pushsection .text.__asm_invalidate_dcache_range, "ax"
+#endif
 ENTRY(__asm_invalidate_dcache_range)
 	mrs	x3, ctr_el0
 	ubfx	x3, x3, #16, #4
diff --git a/arch/arm/cpu/armv8/cache_v8.c b/arch/arm/cpu/armv8/cache_v8.c
index 7c0e3f6d055..d150da4778e 100644
--- a/arch/arm/cpu/armv8/cache_v8.c
+++ b/arch/arm/cpu/armv8/cache_v8.c
@@ -8,6 +8,7 @@
  */
 
 #include <cpu_func.h>
+#include <efi_loader.h>
 #include <hang.h>
 #include <log.h>
 #include <asm/cache.h>
@@ -855,7 +856,8 @@ inline void flush_dcache_all(void)
 /*
  * Invalidates range in all levels of D-cache/unified cache
  */
-void invalidate_dcache_range(unsigned long start, unsigned long stop)
+void __efi_runtime invalidate_dcache_range(unsigned long start,
+					   unsigned long stop)
 {
 	__asm_invalidate_dcache_range(start, stop);
 }
@@ -863,16 +865,19 @@ void invalidate_dcache_range(unsigned long start, unsigned long stop)
 /*
  * Flush range(clean & invalidate) from all levels of D-cache/unified cache
  */
-void flush_dcache_range(unsigned long start, unsigned long stop)
+void __efi_runtime flush_dcache_range(unsigned long start,
+				      unsigned long stop)
 {
 	__asm_flush_dcache_range(start, stop);
 }
 #else
-void invalidate_dcache_range(unsigned long start, unsigned long stop)
+void __efi_runtime invalidate_dcache_range(unsigned long start,
+					   unsigned long stop)
 {
 }
 
-void flush_dcache_range(unsigned long start, unsigned long stop)
+void __efi_runtime flush_dcache_range(unsigned long start,
+				      unsigned long stop)
 {
 }
 #endif /* CONFIG_SYS_DISABLE_DCACHE_OPS */
-- 
2.34.1