[PATCH] ARM: Add V6 aliasing cache flush
Add cache flushing support for aliased V6 caches to
flush_dcache_page.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index c6de48d..4085ed9 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -13,6 +13,29 @@
#include <asm/cacheflush.h>
#include <asm/system.h>
+#include <asm/tlbflush.h>
+
+#ifdef CONFIG_CPU_CACHE_VIPT
+#define ALIAS_FLUSH_START 0xffff4000
+
+#define TOP_PTE(x) pte_offset_kernel(top_pmd, x)
+
+static void flush_pfn_alias(unsigned long pfn, unsigned long vaddr)
+{
+ unsigned long to = ALIAS_FLUSH_START + (CACHE_COLOUR(vaddr) << PAGE_SHIFT);
+
+ set_pte(TOP_PTE(to), pfn_pte(pfn, PAGE_KERNEL));
+ flush_tlb_kernel_page(to);
+
+ asm( "mcrr p15, 0, %1, %0, c14\n"
+ " mcrr p15, 0, %1, %0, c5\n"
+ :
+ : "r" (to), "r" (to + PAGE_SIZE - L1_CACHE_BYTES)
+ : "cc");
+}
+#else
+#define flush_pfn_alias(pfn,vaddr) do { } while (0)
+#endif
static void __flush_dcache_page(struct address_space *mapping, struct page *page)
{
@@ -37,6 +60,18 @@
return;
/*
+ * This is a page cache page. If we have a VIPT cache, we
+ * only need to do one flush - which would be at the relevant
+ * userspace colour, which is congruent with page->index.
+ */
+ if (cache_is_vipt()) {
+ if (cache_is_vipt_aliasing())
+ flush_pfn_alias(page_to_pfn(page),
+ page->index << PAGE_CACHE_SHIFT);
+ return;
+ }
+
+ /*
* There are possible user space mappings of this page:
* - VIVT cache: we need to also write back and invalidate all user
* data in the current VM view associated with this page.
@@ -57,8 +92,6 @@
continue;
offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
flush_cache_page(mpnt, mpnt->vm_start + offset, page_to_pfn(page));
- if (cache_is_vipt())
- break;
}
flush_dcache_mmap_unlock(mapping);
}