This patch is for a problem we observed on an ARC770D and MMUv3
implementation.
The problem was although __flush_dcache_page() returns there were some
cacheline
entries that didn't flush to DDR. In our case updating ARC_REG_DC_PTAG
register
on each cacheline iteration with updated physical address helped flushing
cacheline entries to DDR.
This patch is open for your considerations.
Signed-off-by: Barbaros Tokaoglu <btokao...@airspan.com>
---
arch/arc/mm/cache.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index 8aa1231..d0875a8 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -251,13 +251,6 @@ void __cache_line_loop_v3(phys_addr_t paddr,
unsigned long vaddr,
num_lines = DIV_ROUND_UP(sz, L1_CACHE_BYTES);
/*
- * MMUv3, cache ops require paddr in PTAG reg
- * if V-P const for loop, PTAG can be written once outside loop
- */
- if (full_page)
- write_aux_reg(aux_tag, paddr);
-
- /*
* This is technically for MMU v4, using the MMU v3 programming
model
* Special work for HS38 aliasing I-cache configuration with PAE40
* - upper 8 bits of paddr need to be written into PTAG_HI
@@ -268,10 +261,8 @@ void __cache_line_loop_v3(phys_addr_t paddr,
unsigned long vaddr,
write_aux_reg(ARC_REG_IC_PTAG_HI, (u64)paddr >> 32);
while (num_lines-- > 0) {
- if (!full_page) {
- write_aux_reg(aux_tag, paddr);
- paddr += L1_CACHE_BYTES;
- }
+ write_aux_reg(aux_tag, paddr);
+ paddr += L1_CACHE_BYTES;
write_aux_reg(aux_cmd, vaddr);
vaddr += L1_CACHE_BYTES;
--
2.7.4
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