sh: Fix up single page flushing to use PAGE_SIZE.

Presently The SH-4 cache flushing code uses flush_cache_4096() for most
of the real flushing work, which breaks down to a fixed 4096 unroll and
increment. Not only is this sub-optimal for larger page sizes, it's also
uncovered a bug in sh4_flush_dcache_page() when large page sizes are used
and we have no cache aliases -- resulting in only a part of the page's
D-cache lines being written back.

Signed-off-by: Valentin Sitdikov <valentin.sitdikov@siemens.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 10 insertions, 12 deletions

diff --git a/arch/sh/mm/cache-sh4.c b/arch/sh/mm/cache-sh4.c
index a98c7d8984fa..519e2d16cd06 100644
--- a/arch/sh/mm/cache-sh4.c
+++ b/arch/sh/mm/cache-sh4.c
@@ -26,7 +26,7 @@
 #define MAX_DCACHE_PAGES        64      /* XXX: Tune for ways */
 #define MAX_ICACHE_PAGES        32
 
-static void __flush_cache_4096(unsigned long addr, unsigned long phys,
+static void __flush_cache_one(unsigned long addr, unsigned long phys,
                                unsigned long exec_offset);
 
 /*
@@ -89,8 +89,7 @@ static void __uses_jump_to_uncached sh4_flush_icache_range(void *args)
         local_irq_restore(flags);
 }
 
-static inline void flush_cache_4096(unsigned long start,
-                                    unsigned long phys)
+static inline void flush_cache_one(unsigned long start, unsigned long phys)
 {
         unsigned long flags, exec_offset = 0;
 
@@ -103,8 +102,7 @@ static inline void flush_cache_4096(unsigned long start,
                 exec_offset = 0x20000000;
 
         local_irq_save(flags);
-        __flush_cache_4096(start | SH_CACHE_ASSOC,
-                           P1SEGADDR(phys), exec_offset);
+        __flush_cache_one(start | SH_CACHE_ASSOC, P1SEGADDR(phys), exec_offset);
         local_irq_restore(flags);
 }
 
@@ -129,8 +127,8 @@ static void sh4_flush_dcache_page(void *arg)
 
                 /* Loop all the D-cache */
                 n = boot_cpu_data.dcache.n_aliases;
-                for (i = 0; i < n; i++, addr += 4096)
-                        flush_cache_4096(addr, phys);
+                for (i = 0; i < n; i++, addr += PAGE_SIZE)
+                        flush_cache_one(addr, phys);
         }
 
         wmb();
@@ -318,11 +316,11 @@ static void sh4_flush_cache_page(void *args)
         /* We only need to flush D-cache when we have alias */
         if ((address^phys) & alias_mask) {
                 /* Loop 4K of the D-cache */
-                flush_cache_4096(
+                flush_cache_one(
                         CACHE_OC_ADDRESS_ARRAY | (address & alias_mask),
                         phys);
                 /* Loop another 4K of the D-cache */
-                flush_cache_4096(
+                flush_cache_one(
                         CACHE_OC_ADDRESS_ARRAY | (phys & alias_mask),
                         phys);
         }
@@ -337,7 +335,7 @@ static void sh4_flush_cache_page(void *args)
                  * kernel has never executed the code through its identity
                  * translation.
                  */
-                flush_cache_4096(
+                flush_cache_one(
                         CACHE_IC_ADDRESS_ARRAY | (address & alias_mask),
                         phys);
         }
@@ -393,7 +391,7 @@ static void sh4_flush_cache_range(void *args)
 }
 
 /**
- * __flush_cache_4096
+ * __flush_cache_one
  *
  * @addr:  address in memory mapped cache array
  * @phys:  P1 address to flush (has to match tags if addr has 'A' bit
@@ -406,7 +404,7 @@ static void sh4_flush_cache_range(void *args)
  * operation (purge/write-back) is selected by the lower 2 bits of
  * 'phys'.
  */
-static void __flush_cache_4096(unsigned long addr, unsigned long phys,
+static void __flush_cache_one(unsigned long addr, unsigned long phys,
                                unsigned long exec_offset)
 {
         int way_count;