[PATCH 16/29] ioat: ignore reserved bits for chancnt and xfercap
From: Dan Williams <hidden>
Date: 2009-09-04 02:32:04
Also in:
linux-raid, lkml
Subsystem:
dma generic offload engine subsystem, intel i/oat dma driver, the rest · Maintainers:
Vinod Koul, Dave Jiang, Linus Torvalds
Don't trust that the reserved bits are always zero, also sanity check the returned value. Signed-off-by: Maciej Sosnowski <redacted> Signed-off-by: Dan Williams <redacted> --- drivers/dma/ioat/dma.c | 7 +++++++ drivers/dma/ioat/dma_v2.c | 7 +++++++ 2 files changed, 14 insertions(+), 0 deletions(-)
diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index 08417ad..5173ba9 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c@@ -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);
diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c
index 9bd3d14..589bbc3 100644
--- a/drivers/dma/ioat/dma_v2.c
+++ b/drivers/dma/ioat/dma_v2.c@@ -360,7 +360,14 @@ 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);