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authorVineet Gupta <vgupta@synopsys.com>2013-05-09 20:24:51 +0400
committerVineet Gupta <vgupta@synopsys.com>2013-05-09 20:29:46 +0400
commit4102b53392d6397d80b6e09b516517efacf7ea77 (patch)
treeb79aa87af1b3a1ff39b4a00b889cb806dfe32ae7 /arch/arc/include/asm/tlb.h
parent6ec18a81b22ab2b40df8424f2b5fc6be20ccad87 (diff)
downloadlinux-4102b53392d6397d80b6e09b516517efacf7ea77.tar.xz
ARC: [mm] Aliasing VIPT dcache support 2/4
This is the meat of the series which prevents any dcache alias creation by always keeping the U and K mapping of a page congruent. If a mapping already exists, and other tries to access the page, prev one is flushed to physical page (wback+inv) Essentially flush_dcache_page()/copy_user_highpage() create K-mapping of a page, but try to defer flushing, unless U-mapping exist. When page is actually mapped to userspace, update_mmu_cache() flushes the K-mapping (in certain cases this can be optimised out) Additonally flush_cache_mm(), flush_cache_range(), flush_cache_page() handle the puring of stale userspace mappings on exit/munmap... flush_anon_page() handles the existing U-mapping for anon page before kernel reads it via the GUP path. Note that while not complete, this is enough to boot a simple dynamically linked Busybox based rootfs Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Diffstat (limited to 'arch/arc/include/asm/tlb.h')
-rw-r--r--arch/arc/include/asm/tlb.h11
1 files changed, 9 insertions, 2 deletions
diff --git a/arch/arc/include/asm/tlb.h b/arch/arc/include/asm/tlb.h
index fe91719866a5..85b6df839bd7 100644
--- a/arch/arc/include/asm/tlb.h
+++ b/arch/arc/include/asm/tlb.h
@@ -30,13 +30,20 @@ do { \
/*
* This pair is called at time of munmap/exit to flush cache and TLB entries
* for mappings being torn down.
- * 1) cache-flush part -implemented via tlb_start_vma( ) can be NOP (for now)
- * as we don't support aliasing configs in our VIPT D$.
+ * 1) cache-flush part -implemented via tlb_start_vma( ) for VIPT aliasing D$
* 2) tlb-flush part - implemted via tlb_end_vma( ) flushes the TLB range
*
* Note, read http://lkml.org/lkml/2004/1/15/6
*/
+#ifndef CONFIG_ARC_CACHE_VIPT_ALIASING
#define tlb_start_vma(tlb, vma)
+#else
+#define tlb_start_vma(tlb, vma) \
+do { \
+ if (!tlb->fullmm) \
+ flush_cache_range(vma, vma->vm_start, vma->vm_end); \
+} while(0)
+#endif
#define tlb_end_vma(tlb, vma) \
do { \