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author | Helge Deller <deller@gmx.de> | 2014-01-31 20:33:17 (GMT) |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-02-06 19:22:21 (GMT) |
commit | 62137ca3bf39188bf19a7ceade570ba4bec6761c (patch) | |
tree | 1e4ab1cd8791a5534097a375517a37625e0e580f /arch/parisc/kernel | |
parent | afb6162fa801161e5842a700aa1432e5921f6794 (diff) | |
download | linux-fsl-qoriq-62137ca3bf39188bf19a7ceade570ba4bec6761c.tar.xz |
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/parisc/kernel')
-rw-r--r-- | arch/parisc/kernel/cache.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c index a725455..ac87a40 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; |