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authorDave Jiang <dave.jiang@intel.com>2021-04-20 12:00:34 -0700
committerVinod Koul <vkoul@kernel.org>2021-04-23 23:08:45 +0530
commita16104617d212d4b482568847b25172972b87e60 (patch)
treee553dc21a2522574c21ade3563e6950b20d009e6 /drivers/dma
parent53b2ee7f637c4f1fa2f50dbdb210088e30c11d2b (diff)
downloadlinux-a16104617d212d4b482568847b25172972b87e60.tar.bz2
dmaengine: idxd: remove MSIX masking for interrupt handlers
Remove interrupt masking and just let the hard irq handler keep firing for new events. This is less of a performance impact vs the MMIO readback inside the pci_msi_{mask,unmas}_irq(). Especially with a loaded system those flushes can be stuck behind large amounts of MMIO writes to flush. When guest kernel is running on top of VFIO mdev, mask/unmask causes a vmexit each time and is not desirable. Suggested-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Link: https://lore.kernel.org/r/161894523436.3210025.1834640110556139277.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/idxd/idxd.h1
-rw-r--r--drivers/dma/idxd/init.c4
-rw-r--r--drivers/dma/idxd/irq.c12
3 files changed, 2 insertions, 15 deletions
diff --git a/drivers/dma/idxd/idxd.h b/drivers/dma/idxd/idxd.h
index 87330b6940fa..97c96ca6ab70 100644
--- a/drivers/dma/idxd/idxd.h
+++ b/drivers/dma/idxd/idxd.h
@@ -377,7 +377,6 @@ void idxd_wqs_quiesce(struct idxd_device *idxd);
/* device interrupt control */
void idxd_msix_perm_setup(struct idxd_device *idxd);
void idxd_msix_perm_clear(struct idxd_device *idxd);
-irqreturn_t idxd_irq_handler(int vec, void *data);
irqreturn_t idxd_misc_thread(int vec, void *data);
irqreturn_t idxd_wq_thread(int irq, void *data);
void idxd_mask_error_interrupts(struct idxd_device *idxd);
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index 64dab4de217e..8003f8a25fff 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -102,7 +102,7 @@ static int idxd_setup_interrupts(struct idxd_device *idxd)
}
irq_entry = &idxd->irq_entries[0];
- rc = request_threaded_irq(irq_entry->vector, idxd_irq_handler, idxd_misc_thread,
+ rc = request_threaded_irq(irq_entry->vector, NULL, idxd_misc_thread,
0, "idxd-misc", irq_entry);
if (rc < 0) {
dev_err(dev, "Failed to allocate misc interrupt.\n");
@@ -119,7 +119,7 @@ static int idxd_setup_interrupts(struct idxd_device *idxd)
init_llist_head(&idxd->irq_entries[i].pending_llist);
INIT_LIST_HEAD(&idxd->irq_entries[i].work_list);
- rc = request_threaded_irq(irq_entry->vector, idxd_irq_handler,
+ rc = request_threaded_irq(irq_entry->vector, NULL,
idxd_wq_thread, 0, "idxd-portal", irq_entry);
if (rc < 0) {
dev_err(dev, "Failed to allocate irq %d.\n", irq_entry->vector);
diff --git a/drivers/dma/idxd/irq.c b/drivers/dma/idxd/irq.c
index 43eea5c9cbd4..afee571e0194 100644
--- a/drivers/dma/idxd/irq.c
+++ b/drivers/dma/idxd/irq.c
@@ -102,15 +102,6 @@ static int idxd_device_schedule_fault_process(struct idxd_device *idxd,
return 0;
}
-irqreturn_t idxd_irq_handler(int vec, void *data)
-{
- struct idxd_irq_entry *irq_entry = data;
- struct idxd_device *idxd = irq_entry->idxd;
-
- idxd_mask_msix_vector(idxd, irq_entry->id);
- return IRQ_WAKE_THREAD;
-}
-
static int process_misc_interrupts(struct idxd_device *idxd, u32 cause)
{
struct device *dev = &idxd->pdev->dev;
@@ -237,7 +228,6 @@ irqreturn_t idxd_misc_thread(int vec, void *data)
iowrite32(cause, idxd->reg_base + IDXD_INTCAUSE_OFFSET);
}
- idxd_unmask_msix_vector(idxd, irq_entry->id);
return IRQ_HANDLED;
}
@@ -394,8 +384,6 @@ irqreturn_t idxd_wq_thread(int irq, void *data)
int processed;
processed = idxd_desc_process(irq_entry);
- idxd_unmask_msix_vector(irq_entry->idxd, irq_entry->id);
-
if (processed == 0)
return IRQ_NONE;