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authorHelge Deller <deller@gmx.de>2014-01-31 21:33:17 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-02-06 11:08:17 -0800
commit64a0099626b2ab6403433ef25e458c4d553a81a1 (patch)
tree853ef652965d1df5404edbf593d9b887d17287c2 /arch
parent50920a1dd85602169df04e38248fa582d523c039 (diff)
parisc: fix cache-flushing
commit 57737c49dd72c96cfbcd4f66559f3ffc399aeb4f upstream. This commit: f8dae00684d678afa13041ef170cecfd1297ed40: parisc: Ensure full cache coherency for kmap/kunmap caused negative caching side-effects, e.g. hanging processes with expect and too many inequivalent alias messages from flush_dcache_page() on Debian 5 systems. This patch now partly reverts it and has been in production use on our debian buildd makeservers since a week without any major problems. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: John David Anglin <dave.anglin@bell.net> Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/parisc/include/asm/cacheflush.h2
-rw-r--r--arch/parisc/include/asm/page.h3
-rw-r--r--arch/parisc/kernel/cache.c14
3 files changed, 16 insertions, 3 deletions
diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index 2f9b751878b..de65f66ea64 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -132,7 +132,6 @@ void mark_rodata_ro(void);
static inline void *kmap(struct page *page)
{
might_sleep();
- flush_dcache_page(page);
return page_address(page);
}
@@ -144,7 +143,6 @@ static inline void kunmap(struct page *page)
static inline void *kmap_atomic(struct page *page)
{
pagefault_disable();
- flush_dcache_page(page);
return page_address(page);
}
diff --git a/arch/parisc/include/asm/page.h b/arch/parisc/include/asm/page.h
index c53fc63149e..637fe031aa8 100644
--- a/arch/parisc/include/asm/page.h
+++ b/arch/parisc/include/asm/page.h
@@ -29,7 +29,8 @@ struct page;
void clear_page_asm(void *page);
void copy_page_asm(void *to, void *from);
#define clear_user_page(vto, vaddr, page) clear_page_asm(vto)
-#define copy_user_page(vto, vfrom, vaddr, page) copy_page_asm(vto, vfrom)
+void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
+ struct page *pg);
/* #define CONFIG_PARISC_TMPALIAS */
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index a72545554a3..ac87a40502e 100644
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -388,6 +388,20 @@ void flush_kernel_dcache_page_addr(void *addr)
}
EXPORT_SYMBOL(flush_kernel_dcache_page_addr);
+void copy_user_page(void *vto, void *vfrom, unsigned long vaddr,
+ struct page *pg)
+{
+ /* Copy using kernel mapping. No coherency is needed (all in
+ kunmap) for the `to' page. However, the `from' page needs to
+ be flushed through a mapping equivalent to the user mapping
+ before it can be accessed through the kernel mapping. */
+ preempt_disable();
+ flush_dcache_page_asm(__pa(vfrom), vaddr);
+ preempt_enable();
+ copy_page_asm(vto, vfrom);
+}
+EXPORT_SYMBOL(copy_user_page);
+
void purge_tlb_entries(struct mm_struct *mm, unsigned long addr)
{
unsigned long flags;