From bb3207863014c7310593146f11fbc6573eab43c8 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 8 Sep 2009 12:01:14 -0700 Subject: [PATCH] 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 Signed-off-by: Dan Williams --- drivers/dma/ioat/dma.c | 7 +++++++ drivers/dma/ioat/dma_v2.c | 7 +++++++ 2 files changed, 14 insertions(+) diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c index 08417ad4edca..5173ba97ba31 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 ca1134249341..137cf879265f 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); -- 2.39.2