[PATCH v11 3/7] PCI: endpoint: pci-ep-msi: Add MSI address/data pair mutable check

[Frank Li]

Some MSI controller change address/data pair when irq_set_affinity().
Current PCI endpoint can't support this type MSI controller. So add flag
MSI_FLAG_MSG_IMMUTABLE in include/linux/msi.h, set this flags in ARM GIC
ITS MSI controller and check it when allocate doorbell.

Signed-off-by: Frank Li <Frank.Li at nxp.com>
---
Change from v9 to v11
- new patch
---
 drivers/irqchip/irq-gic-v3-its-msi-parent.c | 1 +
 drivers/pci/endpoint/pci-ep-msi.c           | 8 ++++++++
 include/linux/msi.h                         | 2 ++
 3 files changed, 11 insertions(+)

diff --git a/drivers/irqchip/irq-gic-v3-its-msi-parent.c b/drivers/irqchip/irq-gic-v3-its-msi-parent.c
index 33e94cfc4d506..a34e9bf93f991 100644
--- a/drivers/irqchip/irq-gic-v3-its-msi-parent.c
+++ b/drivers/irqchip/irq-gic-v3-its-msi-parent.c
@@ -16,6 +16,7 @@
 
 #define ITS_MSI_FLAGS_SUPPORTED (MSI_GENERIC_FLAGS_MASK |	\
 				 MSI_FLAG_PCI_MSIX      |	\
+				 MSI_FLAG_MSG_IMMUTABLE |	\
 				 MSI_FLAG_MULTI_PCI_MSI)
 
 #ifdef CONFIG_PCI_MSI
diff --git a/drivers/pci/endpoint/pci-ep-msi.c b/drivers/pci/endpoint/pci-ep-msi.c
index b0a91fde202f3..1c157e0a81456 100644
--- a/drivers/pci/endpoint/pci-ep-msi.c
+++ b/drivers/pci/endpoint/pci-ep-msi.c
@@ -107,6 +107,14 @@ int pci_epf_alloc_doorbell(struct pci_epf *epf, u16 num_db)
 		return -EINVAL;
 	}
 
+	if (!dom->msi_parent_ops)
+		return -EINVAL;
+
+	if (!(dom->msi_parent_ops->supported_flags & MSI_FLAG_MSG_IMMUTABLE)) {
+		dev_err(dev, "Can't support mutable address/data pair MSI controller\n");
+		return -EINVAL;
+	}
+
 	dev_set_msi_domain(dev, dom);
 
 	msg = kcalloc(num_db, sizeof(struct pci_epf_doorbell_msg), GFP_KERNEL);
diff --git a/include/linux/msi.h b/include/linux/msi.h
index b10093c4d00ea..d95d979e4747a 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -556,6 +556,8 @@ enum {
 	MSI_FLAG_PCI_MSIX_ALLOC_DYN	= (1 << 20),
 	/* PCI MSIs cannot be steered separately to CPU cores */
 	MSI_FLAG_NO_AFFINITY		= (1 << 21),
+	/* Address and data pair is mutable when irq_set_affinity() */
+	MSI_FLAG_MSG_IMMUTABLE		= (1 << 22),
 };
 
 /**

-- 
2.34.1