PCI MSI: msi_desc->dev is always initialised

By passing the pci_dev into alloc_msi_entry() we can be sure that
the ->dev entry is always assigned and so we don't need to check it.
Also, we used kzalloc() so we don't need to initialise ->irq to 0.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index b3db438..a658c0f 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -110,7 +110,7 @@ static void msix_flush_writes(struct irq_desc *desc)
        struct msi_desc *entry;
 
        entry = get_irq_desc_msi(desc);
-       BUG_ON(!entry || !entry->dev);
+       BUG_ON(!entry);
        if (entry->msi_attrib.is_msix) {
                int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
                        PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET;
@@ -132,7 +132,7 @@ static int msi_set_mask_bits(struct irq_desc *desc, u32 mask, u32 flag)
        struct msi_desc *entry;
 
        entry = get_irq_desc_msi(desc);
-       BUG_ON(!entry || !entry->dev);
+       BUG_ON(!entry);
        if (entry->msi_attrib.is_msix) {
                int offset = entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
                        PCI_MSIX_ENTRY_VECTOR_CTRL_OFFSET;
@@ -248,19 +248,16 @@ void unmask_msi_irq(unsigned int irq)
 
 static int msi_free_irqs(struct pci_dev* dev);
 
-static struct msi_desc* alloc_msi_entry(void)
+static struct msi_desc *alloc_msi_entry(struct pci_dev *dev)
 {
-       struct msi_desc *entry;
-
-       entry = kzalloc(sizeof(struct msi_desc), GFP_KERNEL);
-       if (!entry)
+       struct msi_desc *desc = kzalloc(sizeof(*desc), GFP_KERNEL);
+       if (!desc)
                return NULL;
 
-       INIT_LIST_HEAD(&entry->list);
-       entry->irq = 0;
-       entry->dev = NULL;
+       INIT_LIST_HEAD(&desc->list);
+       desc->dev = dev;
 
-       return entry;
+       return desc;
 }
 
 static void pci_intx_for_msi(struct pci_dev *dev, int enable)
@@ -351,7 +348,7 @@ static int msi_capability_init(struct pci_dev *dev)
        pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
        pci_read_config_word(dev, msi_control_reg(pos), &control);
        /* MSI Entry Initialization */
-       entry = alloc_msi_entry();
+       entry = alloc_msi_entry(dev);
        if (!entry)
                return -ENOMEM;
 
@@ -362,7 +359,6 @@ static int msi_capability_init(struct pci_dev *dev)
        entry->msi_attrib.masked = 1;
        entry->msi_attrib.default_irq = dev->irq;       /* Save IOAPIC IRQ */
        entry->msi_attrib.pos = pos;
-       entry->dev = dev;
        if (entry->msi_attrib.maskbit) {
                unsigned int base, maskbits, temp;
 
@@ -432,7 +428,7 @@ static int msix_capability_init(struct pci_dev *dev,
 
        /* MSI-X Table Initialization */
        for (i = 0; i < nvec; i++) {
-               entry = alloc_msi_entry();
+               entry = alloc_msi_entry(dev);
                if (!entry)
                        break;
 
@@ -444,7 +440,6 @@ static int msix_capability_init(struct pci_dev *dev,
                entry->msi_attrib.masked = 1;
                entry->msi_attrib.default_irq = dev->irq;
                entry->msi_attrib.pos = pos;
-               entry->dev = dev;
                entry->mask_base = base;
 
                list_add_tail(&entry->list, &dev->msi_list);
@@ -581,7 +576,7 @@ void pci_msi_shutdown(struct pci_dev* dev)
                struct irq_desc *desc = irq_to_desc(dev->irq);
                msi_set_mask_bits(desc, mask, ~mask);
        }
-       if (!entry->dev || entry->msi_attrib.is_msix)
+       if (entry->msi_attrib.is_msix)
                return;
 
        /* Restore dev->irq to its default pin-assertion irq */
@@ -598,7 +593,7 @@ void pci_disable_msi(struct pci_dev* dev)
        pci_msi_shutdown(dev);
 
        entry = list_entry(dev->msi_list.next, struct msi_desc, list);
-       if (!entry->dev || entry->msi_attrib.is_msix)
+       if (entry->msi_attrib.is_msix)
                return;
 
        msi_free_irqs(dev);