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authorDave Jiang <dave.jiang@intel.com>2016-03-10 16:18:40 -0700
committerVinod Koul <vinod.koul@intel.com>2016-03-11 07:55:08 +0530
commitc997e30e7f65f00832abc5d92f7fd3d6ca325402 (patch)
treefc26ea33c4176b5fe81af07a8e4ff8f8e6171dfd /drivers/dma
parentdd4645ebb7d100bb04ba38ec58b499cbe95322fa (diff)
downloadlinux-c997e30e7f65f00832abc5d92f7fd3d6ca325402.tar.bz2
dmaengine: IOATDMA: revise channel reset workaround on CB3.3 platforms
Previously we unloaded the interrupts and reloaded in order to work around a channel reset bug that cleared the MSIX table. This approach just isn't practical when a reset needs to happen in the error handler that just happens to be running in interrupt context (bottom half). It looks like we can work around the hardware issue by just storing a shadow copy of the MSIX table and restore it after reset. Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/ioat/dma.c50
-rw-r--r--drivers/dma/ioat/dma.h5
2 files changed, 19 insertions, 36 deletions
diff --git a/drivers/dma/ioat/dma.c b/drivers/dma/ioat/dma.c
index 14ae9a0994fd..5428746f03fb 100644
--- a/drivers/dma/ioat/dma.c
+++ b/drivers/dma/ioat/dma.c
@@ -804,40 +804,6 @@ ioat_tx_status(struct dma_chan *c, dma_cookie_t cookie,
return dma_cookie_status(c, cookie, txstate);
}
-static int ioat_irq_reinit(struct ioatdma_device *ioat_dma)
-{
- struct pci_dev *pdev = ioat_dma->pdev;
- int irq = pdev->irq, i;
-
- if (!is_bwd_ioat(pdev))
- return 0;
-
- switch (ioat_dma->irq_mode) {
- case IOAT_MSIX:
- for (i = 0; i < ioat_dma->dma_dev.chancnt; i++) {
- struct msix_entry *msix = &ioat_dma->msix_entries[i];
- struct ioatdma_chan *ioat_chan;
-
- ioat_chan = ioat_chan_by_index(ioat_dma, i);
- devm_free_irq(&pdev->dev, msix->vector, ioat_chan);
- }
-
- pci_disable_msix(pdev);
- break;
- case IOAT_MSI:
- pci_disable_msi(pdev);
- /* fall through */
- case IOAT_INTX:
- devm_free_irq(&pdev->dev, irq, ioat_dma);
- break;
- default:
- return 0;
- }
- ioat_dma->irq_mode = IOAT_NOIRQ;
-
- return ioat_dma_setup_interrupts(ioat_dma);
-}
-
int ioat_reset_hw(struct ioatdma_chan *ioat_chan)
{
/* throw away whatever the channel was doing and get it
@@ -877,9 +843,21 @@ int ioat_reset_hw(struct ioatdma_chan *ioat_chan)
}
}
+ if (is_bwd_ioat(pdev) && (ioat_dma->irq_mode == IOAT_MSIX)) {
+ ioat_dma->msixtba0 = readq(ioat_dma->reg_base + 0x1000);
+ ioat_dma->msixdata0 = readq(ioat_dma->reg_base + 0x1008);
+ ioat_dma->msixpba = readq(ioat_dma->reg_base + 0x1800);
+ }
+
+
err = ioat_reset_sync(ioat_chan, msecs_to_jiffies(200));
- if (!err)
- err = ioat_irq_reinit(ioat_dma);
+ if (!err) {
+ if (is_bwd_ioat(pdev) && (ioat_dma->irq_mode == IOAT_MSIX)) {
+ writeq(ioat_dma->msixtba0, ioat_dma->reg_base + 0x1000);
+ writeq(ioat_dma->msixdata0, ioat_dma->reg_base + 0x1008);
+ writeq(ioat_dma->msixpba, ioat_dma->reg_base + 0x1800);
+ }
+ }
if (err)
dev_err(&pdev->dev, "Failed to reset: %d\n", err);
diff --git a/drivers/dma/ioat/dma.h b/drivers/dma/ioat/dma.h
index 57a9b83db455..a9bc1a15b0d1 100644
--- a/drivers/dma/ioat/dma.h
+++ b/drivers/dma/ioat/dma.h
@@ -86,6 +86,11 @@ struct ioatdma_device {
struct dca_provider *dca;
enum ioat_irq_mode irq_mode;
u32 cap;
+
+ /* shadow version for CB3.3 chan reset errata workaround */
+ u64 msixtba0;
+ u64 msixdata0;
+ u32 msixpba;
};
struct ioat_descs {