PCI/MSI: Simplify PCI MSI code by initializing msi_desc.nvec_used earlier

Simplify PCI MSI code by initializing msi_desc.nvec_used and
msi_desc.msi_attrib.multiple when creating MSI descriptors.

Also remove redundant checks in IRQ remapping drivers, PCI MSI core
already guarantees these.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Yingjoe Chen <yingjoe.chen@mediatek.com>
Cc: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
index 74a1767c89b512fa09ef2698b918211451c8e8de..2c3f5ad010987d77ddda7b271fb847360cd4bc42 100644 (file)
--- a/drivers/iommu/irq_remapping.c
+++ b/drivers/iommu/irq_remapping.c
@@ -56,19 +56,13 @@ static int do_setup_msi_irqs(struct pci_dev *dev, int nvec)
        unsigned int irq;
        struct msi_desc *msidesc;
 
-       WARN_ON(!list_is_singular(&dev->msi_list));
        msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
-       WARN_ON(msidesc->irq);
-       WARN_ON(msidesc->msi_attrib.multiple);
-       WARN_ON(msidesc->nvec_used);
 
        irq = irq_alloc_hwirqs(nvec, dev_to_node(&dev->dev));
        if (irq == 0)
                return -ENOSPC;
 
        nvec_pow2 = __roundup_pow_of_two(nvec);
-       msidesc->nvec_used = nvec;
-       msidesc->msi_attrib.multiple = ilog2(nvec_pow2);
        for (sub_handle = 0; sub_handle < nvec; sub_handle++) {
                if (!sub_handle) {
                        index = msi_alloc_remapped_irq(dev, irq, nvec_pow2);
@@ -96,8 +90,6 @@ error:
         * IRQs from tearing down again in default_teardown_msi_irqs()
         */
        msidesc->irq = 0;
-       msidesc->nvec_used = 0;
-       msidesc->msi_attrib.multiple = 0;
 
        return ret;
 }

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index f1eb873eeaa6fdb9bdf376f3d864b9b3920883e4..df0170b8da730fae89afec4fbb87cdf0d6d5732e 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -101,19 +101,13 @@ int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
  */
 void default_teardown_msi_irqs(struct pci_dev *dev)
 {
+       int i;
        struct msi_desc *entry;
 
-       list_for_each_entry(entry, &dev->msi_list, list) {
-               int i, nvec;
-               if (entry->irq == 0)
-                       continue;
-               if (entry->nvec_used)
-                       nvec = entry->nvec_used;
-               else
-                       nvec = 1 << entry->msi_attrib.multiple;
-               for (i = 0; i < nvec; i++)
-                       arch_teardown_msi_irq(entry->irq + i);
-       }
+       list_for_each_entry(entry, &dev->msi_list, list)
+               if (entry->irq)
+                       for (i = 0; i < entry->nvec_used; i++)
+                               arch_teardown_msi_irq(entry->irq + i);
 }
 
 void __weak arch_teardown_msi_irqs(struct pci_dev *dev)
@@ -363,19 +357,12 @@ static void free_msi_irqs(struct pci_dev *dev)
        struct msi_desc *entry, *tmp;
        struct attribute **msi_attrs;
        struct device_attribute *dev_attr;
-       int count = 0;
+       int i, count = 0;
 
-       list_for_each_entry(entry, &dev->msi_list, list) {
-               int i, nvec;
-               if (!entry->irq)
-                       continue;
-               if (entry->nvec_used)
-                       nvec = entry->nvec_used;
-               else
-                       nvec = 1 << entry->msi_attrib.multiple;
-               for (i = 0; i < nvec; i++)
-                       BUG_ON(irq_has_action(entry->irq + i));
-       }
+       list_for_each_entry(entry, &dev->msi_list, list)
+               if (entry->irq)
+                       for (i = 0; i < entry->nvec_used; i++)
+                               BUG_ON(irq_has_action(entry->irq + i));
 
        arch_teardown_msi_irqs(dev);
 
@@ -566,7 +553,7 @@ error_attrs:
        return ret;
 }
 
-static struct msi_desc *msi_setup_entry(struct pci_dev *dev)
+static struct msi_desc *msi_setup_entry(struct pci_dev *dev, int nvec)
 {
        u16 control;
        struct msi_desc *entry;
@@ -584,6 +571,8 @@ static struct msi_desc *msi_setup_entry(struct pci_dev *dev)
        entry->msi_attrib.maskbit       = !!(control & PCI_MSI_FLAGS_MASKBIT);
        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;
 
        if (control & PCI_MSI_FLAGS_64BIT)
                entry->mask_pos = dev->msi_cap + PCI_MSI_MASK_64;
@@ -616,7 +605,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec)
 
        msi_set_enable(dev, 0); /* Disable MSI during set up */
 
-       entry = msi_setup_entry(dev);
+       entry = msi_setup_entry(dev, nvec);
        if (!entry)
                return -ENOMEM;
 
@@ -687,6 +676,7 @@ static int msix_setup_entries(struct pci_dev *dev, void __iomem *base,
                entry->msi_attrib.entry_nr      = entries[i].entry;
                entry->msi_attrib.default_irq   = dev->irq;
                entry->mask_base                = base;
+               entry->nvec_used                = 1;
 
                list_add_tail(&entry->list, &dev->msi_list);
        }