[PATCH 25/31] frv: handle page-less SG entries

Christoph Hellwig hch at lst.de
Wed Aug 12 17:05:44 AEST 2015

Only call kmap_atomic_primary when the SG entry is mapped into
kernel virtual space.

XXX: the code already looks odd due to the lack of pairing between
kmap_atomic_primary and kunmap_atomic_primary.  Does it work either
before or after this patch?

Signed-off-by: Christoph Hellwig <hch at lst.de>
 arch/frv/mb93090-mb00/pci-dma.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/frv/mb93090-mb00/pci-dma.c b/arch/frv/mb93090-mb00/pci-dma.c
index 4d1f01d..77b3a1c 100644
--- a/arch/frv/mb93090-mb00/pci-dma.c
+++ b/arch/frv/mb93090-mb00/pci-dma.c
@@ -63,6 +63,9 @@ int dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
 	dampr2 = __get_DAMPR(2);
 	for_each_sg(sglist, sg, nents, i) {
+		if (!sg_has_page(sg))
+			continue;
 		vaddr = kmap_atomic_primary(sg_page(sg));
 		frv_dcache_writeback((unsigned long) vaddr,

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