From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: [PATCH 16/29] ioat: ignore reserved bits for chancnt and xfercap Date: Thu, 03 Sep 2009 19:31:51 -0700 Message-ID: <20090904023151.32667.13156.stgit@dwillia2-linux.ch.intel.com> References: <20090904022733.32667.77626.stgit@dwillia2-linux.ch.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: linux-raid@vger.kernel.org, netdev@vger.kernel.org, Maciej Sosnowski To: linux-kernel@vger.kernel.org Return-path: In-Reply-To: <20090904022733.32667.77626.stgit@dwillia2-linux.ch.intel.com> Sender: linux-raid-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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(+), 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);