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| author | Maciej Sosnowski | 2009-02-26 11:04:23 +0100 |
|---|---|---|
| committer | Dan Williams | 2009-03-05 00:04:39 +0100 |
| commit | 49bc46360d68156ce82b2b1a12badb80078453a0 (patch) | |
| tree | df7f187e26e3443384074376f52e47e516cf1bca /drivers/dma/ioat_dca.c | |
| parent | dmaengine: update kerneldoc (diff) | |
| download | kernel-qcow2-linux-49bc46360d68156ce82b2b1a12badb80078453a0.tar.gz kernel-qcow2-linux-49bc46360d68156ce82b2b1a12badb80078453a0.tar.xz kernel-qcow2-linux-49bc46360d68156ce82b2b1a12badb80078453a0.zip | |
I/OAT: add verification for proper APICID_TAG_MAP setting by BIOS
BIOS versions for systems with I/OAT ver.2 have been found
which fail to program APICID_TAG_MAP for DCA.
The ioatdma driver should recognize incorrectly set APICID_TAG_MAP
and disable DCA in that case.
Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/dma/ioat_dca.c')
| -rw-r--r-- | drivers/dma/ioat_dca.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/drivers/dma/ioat_dca.c b/drivers/dma/ioat_dca.c index 6cf622da0286..78705ca7d36a 100644 --- a/drivers/dma/ioat_dca.c +++ b/drivers/dma/ioat_dca.c @@ -49,6 +49,23 @@ #define DCA_TAG_MAP_MASK 0xDF +/* expected tag map bytes for I/OAT ver.2 */ +#define DCA2_TAG_MAP_BYTE0 0x80 +#define DCA2_TAG_MAP_BYTE1 0x0 +#define DCA2_TAG_MAP_BYTE2 0x81 +#define DCA2_TAG_MAP_BYTE3 0x82 +#define DCA2_TAG_MAP_BYTE4 0x82 + +/* verify if tag map matches expected values */ +static inline int dca2_tag_map_valid(u8 *tag_map) +{ + return ((tag_map[0] == DCA2_TAG_MAP_BYTE0) && + (tag_map[1] == DCA2_TAG_MAP_BYTE1) && + (tag_map[2] == DCA2_TAG_MAP_BYTE2) && + (tag_map[3] == DCA2_TAG_MAP_BYTE3) && + (tag_map[4] == DCA2_TAG_MAP_BYTE4)); +} + /* * "Legacy" DCA systems do not implement the DCA register set in the * I/OAT device. Software needs direct support for their tag mappings. @@ -452,6 +469,13 @@ struct dca_provider *ioat2_dca_init(struct pci_dev *pdev, void __iomem *iobase) ioatdca->tag_map[i] = 0; } + if (!dca2_tag_map_valid(ioatdca->tag_map)) { + dev_err(&pdev->dev, "APICID_TAG_MAP set incorrectly by BIOS, " + "disabling DCA\n"); + free_dca_provider(dca); + return NULL; + } + err = register_dca_provider(dca, &pdev->dev); if (err) { free_dca_provider(dca); |