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authorLinus Torvalds <torvalds@linux-foundation.org>2013-06-19 06:19:46 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2013-06-19 06:19:46 -1000
commit262fd6ff408dd6b89831a8ea14c2abd59452cfdd (patch)
tree66c19e216f04946d8b14bea270189fc67fa8b0d8 /arch/arm/mm/flush.c
parent17858ca65eef148d335ffd4cfc09228a1c1cbfb5 (diff)
parent19ab428f4b7988ef3ac727c680efc193ef53ce14 (diff)
Merge branch 'fixes' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM fixes from Russell King: "The larger changes this time are - "ARM: 7755/1: handle user space mapped pages in flush_kernel_dcache_page" which fixes more data corruption problems with O_DIRECT - "ARM: 7759/1: decouple CPU offlining from reboot/shutdown" which gets us back to working shutdown/reboot on SMP platforms - "ARM: 7752/1: errata: LoUIS bit field in CLIDR register is incorrect" which fixes a shutdown regression found in v3.10 on Versatile Express platforms. The remainder are the quite small, maybe one or two line changes" * 'fixes' of git://git.linaro.org/people/rmk/linux-arm: ARM: 7759/1: decouple CPU offlining from reboot/shutdown ARM: 7756/1: zImage/virt: remove hyp-stub.S during distclean ARM: 7755/1: handle user space mapped pages in flush_kernel_dcache_page ARM: 7754/1: Fix the CPU ID and the mask associated to the PJ4B ARM: 7753/1: map_init_section flushes incorrect pmd ARM: 7752/1: errata: LoUIS bit field in CLIDR register is incorrect
Diffstat (limited to 'arch/arm/mm/flush.c')
-rw-r--r--arch/arm/mm/flush.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/arm/mm/flush.c b/arch/arm/mm/flush.c
index 0d473cce501..32aa5861119 100644
--- a/arch/arm/mm/flush.c
+++ b/arch/arm/mm/flush.c
@@ -301,6 +301,39 @@ void flush_dcache_page(struct page *page)
EXPORT_SYMBOL(flush_dcache_page);
/*
+ * Ensure cache coherency for the kernel mapping of this page. We can
+ * assume that the page is pinned via kmap.
+ *
+ * If the page only exists in the page cache and there are no user
+ * space mappings, this is a no-op since the page was already marked
+ * dirty at creation. Otherwise, we need to flush the dirty kernel
+ * cache lines directly.
+ */
+void flush_kernel_dcache_page(struct page *page)
+{
+ if (cache_is_vivt() || cache_is_vipt_aliasing()) {
+ struct address_space *mapping;
+
+ mapping = page_mapping(page);
+
+ if (!mapping || mapping_mapped(mapping)) {
+ void *addr;
+
+ addr = page_address(page);
+ /*
+ * kmap_atomic() doesn't set the page virtual
+ * address for highmem pages, and
+ * kunmap_atomic() takes care of cache
+ * flushing already.
+ */
+ if (!IS_ENABLED(CONFIG_HIGHMEM) || addr)
+ __cpuc_flush_dcache_area(addr, PAGE_SIZE);
+ }
+ }
+}
+EXPORT_SYMBOL(flush_kernel_dcache_page);
+
+/*
* Flush an anonymous page so that users of get_user_pages()
* can safely access the data. The expected sequence is:
*