genirq/msi: Add cpumask allocation to alloc_msi_entry

For irq spreading want to store affinity masks in the msi_entry. Add the
infrastructure for it.

We allocate an array of cpumasks with an array size of the number of used
vectors in the entry, so we can hand in the information per linux interrupt
later.

As we hand in the number of used vectors, we assign them right
away. Convert all the call sites.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: axboe@fb.com
Cc: keith.busch@intel.com
Cc: agordeev@redhat.com
Cc: linux-block@vger.kernel.org
Cc: Christoph Hellwig <hch@lst.de>
Link: http://lkml.kernel.org/r/1473862739-15032-2-git-send-email-hch@lst.de

drivers/base/platform-msi.c

@@ -142,13 +142,12 @@ static int platform_msi_alloc_descs_with_irq(struct device *dev, int virq,
 	}
 
 	for (i = 0; i < nvec; i++) {
-		desc = alloc_msi_entry(dev);
+		desc = alloc_msi_entry(dev, 1, NULL);
 		if (!desc)
 			break;
 
 		desc->platform.msi_priv_data = data;
 		desc->platform.msi_index = base + i;
-		desc->nvec_used = 1;
 		desc->irq = virq ? virq + i : 0;
 
 		list_add_tail(&desc->list, dev_to_msi_list(dev));

drivers/pci/msi.c

@@ -555,7 +555,7 @@ static struct msi_desc *msi_setup_entry(struct pci_dev *dev, int nvec)
 	struct msi_desc *entry;
 
 	/* MSI Entry Initialization */
-	entry = alloc_msi_entry(&dev->dev);
+	entry = alloc_msi_entry(&dev->dev, nvec, NULL);
 	if (!entry)
 		return NULL;
 
@@ -568,7 +568,6 @@ static struct msi_desc *msi_setup_entry(struct pci_dev *dev, int nvec)
 	entry->msi_attrib.default_irq	= dev->irq;	/* Save IOAPIC IRQ */
 	entry->msi_attrib.multi_cap	= (control & PCI_MSI_FLAGS_QMASK) >> 1;
 	entry->msi_attrib.multiple	= ilog2(__roundup_pow_of_two(nvec));
-	entry->nvec_used		= nvec;
 	entry->affinity			= dev->irq_affinity;
 
 	if (control & PCI_MSI_FLAGS_64BIT)
@@ -693,7 +692,7 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
 			mask = cpumask_of(cpu);
 		}
 
-		entry = alloc_msi_entry(&dev->dev);
+		entry = alloc_msi_entry(&dev->dev, 1, NULL);
 		if (!entry) {
 			if (!i)
 				iounmap(base);
@@ -711,7 +710,6 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
 			entry->msi_attrib.entry_nr = i;
 		entry->msi_attrib.default_irq	= dev->irq;
 		entry->mask_base		= base;
-		entry->nvec_used		= 1;
 		entry->affinity			= mask;
 
 		list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));

drivers/staging/fsl-mc/bus/mc-msi.c

@@ -213,7 +213,7 @@ static int fsl_mc_msi_alloc_descs(struct device *dev, unsigned int irq_count)
 	struct msi_desc *msi_desc;
 
 	for (i = 0; i < irq_count; i++) {
-		msi_desc = alloc_msi_entry(dev);
+		msi_desc = alloc_msi_entry(dev, 1, NULL);
 		if (!msi_desc) {
 			dev_err(dev, "Failed to allocate msi entry\n");
 			error = -ENOMEM;
@@ -221,7 +221,6 @@ static int fsl_mc_msi_alloc_descs(struct device *dev, unsigned int irq_count)
 		}
 
 		msi_desc->fsl_mc.msi_index = i;
-		msi_desc->nvec_used = 1;
 		INIT_LIST_HEAD(&msi_desc->list);
 		list_add_tail(&msi_desc->list, dev_to_msi_list(dev));
 	}

include/linux/msi.h

@@ -68,7 +68,7 @@ struct msi_desc {
 	unsigned int			nvec_used;
 	struct device			*dev;
 	struct msi_msg			msg;
-	const struct cpumask		*affinity;
+	struct cpumask			*affinity;
 
 	union {
 		/* PCI MSI/X specific data */
@@ -123,7 +123,8 @@ static inline void *msi_desc_to_pci_sysdata(struct msi_desc *desc)
 }
 #endif /* CONFIG_PCI_MSI */
 
-struct msi_desc *alloc_msi_entry(struct device *dev);
+struct msi_desc *alloc_msi_entry(struct device *dev, int nvec,
+				 const struct cpumask *affinity);
 void free_msi_entry(struct msi_desc *entry);
 void __pci_read_msi_msg(struct msi_desc *entry, struct msi_msg *msg);
 void __pci_write_msi_msg(struct msi_desc *entry, struct msi_msg *msg);

kernel/irq/msi.c

@@ -18,20 +18,42 @@
 /* Temparory solution for building, will be removed later */
 #include <linux/pci.h>
 
-struct msi_desc *alloc_msi_entry(struct device *dev)
+/**
+ * alloc_msi_entry - Allocate an initialize msi_entry
+ * @dev:	Pointer to the device for which this is allocated
+ * @nvec:	The number of vectors used in this entry
+ * @affinity:	Optional pointer to an affinity mask array size of @nvec
+ *
+ * If @affinity is not NULL then a an affinity array[@nvec] is allocated
+ * and the affinity masks from @affinity are copied.
+ */
+struct msi_desc *
+alloc_msi_entry(struct device *dev, int nvec, const struct cpumask *affinity)
 {
-	struct msi_desc *desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+	struct msi_desc *desc;
+
+	desc = kzalloc(sizeof(*desc), GFP_KERNEL);
 	if (!desc)
 		return NULL;
 
 	INIT_LIST_HEAD(&desc->list);
 	desc->dev = dev;
+	desc->nvec_used = nvec;
+	if (affinity) {
+		desc->affinity = kmemdup(affinity,
+			nvec * sizeof(*desc->affinity), GFP_KERNEL);
+		if (!desc->affinity) {
+			kfree(desc);
+			return NULL;
+		}
+	}
 
 	return desc;
 }
 
 void free_msi_entry(struct msi_desc *entry)
 {
+	kfree(entry->affinity);
 	kfree(entry);
 }