[PATCH 13/31] sparc/ldc: handle page-less SG entries

From: Christoph Hellwig
Date: Wed Aug 12 2015 - 03:17:21 EST


Use

sg_phys(sg) & PAGE_MASK

instead of

page_to_pfn(sg_page(sg)) << PAGE_SHIFT

to get at the page-aligned physical address ofa SG entry, so that
we don't require a page backing for SG entries.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/sparc/kernel/ldc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/sparc/kernel/ldc.c b/arch/sparc/kernel/ldc.c
index 1ae5eb1..0a29974 100644
--- a/arch/sparc/kernel/ldc.c
+++ b/arch/sparc/kernel/ldc.c
@@ -2051,7 +2051,7 @@ static void fill_cookies(struct cookie_state *sp, unsigned long pa,

static int sg_count_one(struct scatterlist *sg)
{
- unsigned long base = page_to_pfn(sg_page(sg)) << PAGE_SHIFT;
+ unsigned long base = sg_phys(sg) & PAGE_MASK;
long len = sg->length;

if ((sg->offset | len) & (8UL - 1))
@@ -2114,7 +2114,7 @@ int ldc_map_sg(struct ldc_channel *lp,
state.nc = 0;

for_each_sg(sg, s, num_sg, i) {
- fill_cookies(&state, page_to_pfn(sg_page(s)) << PAGE_SHIFT,
+ fill_cookies(&state, sg_phys(s) & PAGE_MASK,
s->offset, s->length);
}

--
1.9.1

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