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>
This commit is contained in:
Dan Williams 2009-09-08 12:01:14 -07:00
parent 4fb9b9e8d5
commit bb32078630
2 changed files with 14 additions and 0 deletions

View File

@ -132,7 +132,14 @@ static int ioat1_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_scale = readb(device->reg_base + IOAT_XFERCAP_OFFSET);
xfercap_scale &= 0x1f; /* bits [4:0] valid */
xfercap = (xfercap_scale == 0 ? -1 : (1UL << xfercap_scale));
dev_dbg(dev, "%s: xfercap = %d\n", __func__, xfercap);

View File

@ -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);