[PATCH 5.13 007/175] dmaengine: idxd: fix setup sequence for MSIXPERM table

From: Greg Kroah-Hartman
Date: Tue Aug 10 2021 - 13:54:50 EST


From: Dave Jiang <dave.jiang@xxxxxxxxx>

[ Upstream commit d5c10e0fc8645342fe5c9796b00c84ab078cd713 ]

The MSIX permission table should be programmed BEFORE request_irq()
happens. This prevents any possibility of an interrupt happening before the
MSIX perm table is setup, however slight.

Fixes: 6df0e6c57dfc ("dmaengine: idxd: clear MSIX permission entry on shutdown")
Sign-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Link: https://lore.kernel.org/r/162456741222.1138073.1298447364671237896.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Vinod Koul <vkoul@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/dma/idxd/init.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 442d55c11a5f..4bc80eb6b9e7 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -102,6 +102,8 @@ static int idxd_setup_interrupts(struct idxd_device *idxd)
spin_lock_init(&idxd->irq_entries[i].list_lock);
}

+ idxd_msix_perm_setup(idxd);
+
irq_entry = &idxd->irq_entries[0];
rc = request_threaded_irq(irq_entry->vector, NULL, idxd_misc_thread,
0, "idxd-misc", irq_entry);
@@ -148,7 +150,6 @@ static int idxd_setup_interrupts(struct idxd_device *idxd)
}

idxd_unmask_error_interrupts(idxd);
- idxd_msix_perm_setup(idxd);
return 0;

err_wq_irqs:
@@ -162,6 +163,7 @@ static int idxd_setup_interrupts(struct idxd_device *idxd)
err_misc_irq:
/* Disable error interrupt generation */
idxd_mask_error_interrupts(idxd);
+ idxd_msix_perm_clear(idxd);
err_irq_entries:
pci_free_irq_vectors(pdev);
dev_err(dev, "No usable interrupts\n");
--
2.30.2