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authorDan Williams <dan.j.williams@intel.com>2009-09-08 12:01:14 -0700
committerDan Williams <dan.j.williams@intel.com>2009-09-08 17:30:24 -0700
commitbb3207863014c7310593146f11fbc6573eab43c8 (patch)
treed54da64e459d28969cdd9250cadaaa581cbae43d /drivers/dma/ioat/dma_v2.c
parent4fb9b9e8d55880523db550043dfb204696dd0422 (diff)
ioat: ignore reserved bits for chancnt and xfercap
Don't trust that the reserved bits are always zero, also sanity check the returned value. Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dma/ioat/dma_v2.c')
-rw-r--r--drivers/dma/ioat/dma_v2.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c
index ca113424934..137cf879265 100644
--- a/drivers/dma/ioat/dma_v2.c
+++ b/drivers/dma/ioat/dma_v2.c
@@ -359,7 +359,14 @@ static int ioat2_enumerate_channels(struct ioatdma_device *device)
INIT_LIST_HEAD(&dma->channels);
dma->chancnt = readb(device->reg_base + IOAT_CHANCNT_OFFSET);
+ dma->chancnt &= 0x1f; /* bits [4:0] valid */
+ if (dma->chancnt > ARRAY_SIZE(device->idx)) {
+ dev_warn(dev, "(%d) exceeds max supported channels (%zu)\n",
+ dma->chancnt, ARRAY_SIZE(device->idx));
+ dma->chancnt = ARRAY_SIZE(device->idx);
+ }
xfercap_log = readb(device->reg_base + IOAT_XFERCAP_OFFSET);
+ xfercap_log &= 0x1f; /* bits [4:0] valid */
if (xfercap_log == 0)
return 0;
dev_dbg(dev, "%s: xfercap = %d\n", __func__, 1 << xfercap_log);