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| author | Herbert Xu <herbert@gondor.apana.org.au> | 2015-06-01 16:22:03 +0800 |
|---|---|---|
| committer | Herbert Xu <herbert@gondor.apana.org.au> | 2015-06-03 10:51:25 +0800 |
| commit | 160544075f2a4028209721723a51f16add7b08b9 (patch) | |
| tree | 06a0f03134acaf222ed0b23a47d2a1e40cdd7808 /crypto/scatterwalk.c | |
| parent | b7c89d9e2fef1c9f4c9d8bacf0c1459e30561289 (diff) | |
| download | linux-stable-160544075f2a4028209721723a51f16add7b08b9.tar.gz linux-stable-160544075f2a4028209721723a51f16add7b08b9.tar.bz2 linux-stable-160544075f2a4028209721723a51f16add7b08b9.zip | |
crypto: scatterwalk - Hide PageSlab call to optimise away flush_dcache_page
On architectures where flush_dcache_page is not needed, we will
end up generating all the code up to the PageSlab call. This is
because PageSlab operates on a volatile pointer and thus cannot
be optimised away.
This patch works around this by checking whether flush_dcache_page
is needed before we call PageSlab which then allows PageSlab to be
compiled awy.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/scatterwalk.c')
| -rw-r--r-- | crypto/scatterwalk.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/crypto/scatterwalk.c b/crypto/scatterwalk.c index 2ef9cbbc5dbf..ea5815c5e128 100644 --- a/crypto/scatterwalk.c +++ b/crypto/scatterwalk.c @@ -54,7 +54,11 @@ static void scatterwalk_pagedone(struct scatter_walk *walk, int out, struct page *page; page = sg_page(walk->sg) + ((walk->offset - 1) >> PAGE_SHIFT); - if (!PageSlab(page)) + /* Test ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE first as + * PageSlab cannot be optimised away per se due to + * use of volatile pointer. + */ + if (ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE && !PageSlab(page)) flush_dcache_page(page); } |