4.9-stable patches

[thirdparty/kernel/stable-queue.git] / releases / 2.6.32.9 / call-flush_dcache_page-after-pio-data-transfers-in-libata-sff.c.patch

From 2d68b7fe55d9e19a8a868224ed0dfd6526568521 Mon Sep 17 00:00:00 2001
From: Catalin Marinas <catalin.marinas@arm.com>
Date: Thu, 4 Feb 2010 01:04:50 -0500
Subject: [libata] Call flush_dcache_page after PIO data transfers in libata-sff.c

From: Catalin Marinas <catalin.marinas@arm.com>

commit 2d68b7fe55d9e19a8a868224ed0dfd6526568521 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 drivers/ata/libata-sff.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -893,6 +893,9 @@ static void ata_pio_sector(struct ata_qu
 				       do_write);
 	}
 
+	if (!do_write)
+		flush_dcache_page(page);
+
 	qc->curbytes += qc->sect_size;
 	qc->cursg_ofs += qc->sect_size;