[libata] Call flush_dcache_page after PIO data transfers in libata-sff.c

flush_dcache_page() must be called after (!ATA_TFLAG_WRITE) the
data copying to avoid D-cache aliasing with user space or I-D cache
coherency issues (when reading data from an ATA device using PIO,
the kernel dirties the D-cache but there is no flush_dcache_page()
required on Harvard architectures).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 741065c9da6700245a2ddb70f19908e3589f85c1..730ef3c384ca190818857c89ab044006dccfe75d 100644 (file)
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -893,6 +893,9 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
                                       do_write);
        }
 
+       if (!do_write)
+               flush_dcache_page(page);
+
        qc->curbytes += qc->sect_size;
        qc->cursg_ofs += qc->sect_size;