[PATCH V4 1/3] driver core: mark device as irq affinity managed if any irq is managed

Ming Lei
2021-07-15T12:09:08Z

irq vector allocation with managed affinity may be used by driver, and
blk-mq needs this info because managed irq will be shutdown when all
CPUs in the affinity mask are offline.

The info of using managed irq is often produced by drivers(pci subsystem,
platform device, ...), and it is consumed by blk-mq, so different subsystems
are involved in this info flow

Address this issue by adding one field of .irq_affinity_managed into
'struct device'.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
drivers/base/platform.c | 7 +++++++
drivers/pci/msi.c | 3 +++
include/linux/device.h | 1 +
3 files changed, 11 insertions(+)

diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 8640578f45e9..d28cb91d5cf9 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -388,6 +388,13 @@ int devm_platform_get_irqs_affinity(struct platform_device *dev,
ptr->irq[i], ret);
goto err_free_desc;
}
+
+ /*
+ * mark the device as irq affinity managed if any irq affinity
+ * descriptor is managed
+ */
+ if (desc[i].is_managed)
+ dev->dev.irq_affinity_managed = true;
}

devres_add(&dev->dev, ptr);
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 3d6db20d1b2b..7ddec90b711d 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1197,6 +1197,7 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
if (flags & PCI_IRQ_AFFINITY) {
if (!affd)
affd = &msi_default_affd;
+ dev->dev.irq_affinity_managed = true;
} else {
if (WARN_ON(affd))
affd = NULL;
@@ -1215,6 +1216,8 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
return nvecs;
}

+ dev->dev.irq_affinity_managed = false;
+
/* use legacy IRQ if allowed */
if (flags & PCI_IRQ_LEGACY) {
if (min_vecs == 1 && dev->irq) {
diff --git a/include/linux/device.h b/include/linux/device.h
index 59940f1744c1..9ec6e671279e 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -569,6 +569,7 @@ struct device {
#ifdef CONFIG_DMA_OPS_BYPASS
bool dma_ops_bypass : 1;
#endif
+ bool irq_affinity_managed : 1;
};

/**
--
2.31.1