arm64: Implement pmem API support

Add a clean-to-point-of-persistence cache maintenance helper, and wire
up the basic architectural support for the pmem driver based on it.

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[catalin.marinas@arm.com: move arch_*_pmem() functions to arch/arm64/mm/flush.c]
[catalin.marinas@arm.com: change dmb(sy) to dmb(osh)]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
index ed47fbbb4b05..7f1dbe962cf5 100644
--- a/arch/arm64/mm/cache.S
+++ b/arch/arm64/mm/cache.S
@@ -172,6 +172,20 @@ ENDPIPROC(__clean_dcache_area_poc)
 ENDPROC(__dma_clean_area)
 
 /*
+ *      __clean_dcache_area_pop(kaddr, size)
+ *
+ *      Ensure that any D-cache lines for the interval [kaddr, kaddr+size)
+ *      are cleaned to the PoP.
+ *
+ *      - kaddr   - kernel address
+ *      - size    - size in question
+ */
+ENTRY(__clean_dcache_area_pop)
+        dcache_by_line_op cvap, sy, x0, x1, x2, x3
+        ret
+ENDPIPROC(__clean_dcache_area_pop)
+
+/*
  *      __dma_flush_area(start, size)
  *
  *      clean & invalidate D / U line