On Tue, Nov 04, 2014 at 08:01:53PM +0800, Jiang Liu wrote:
PCI/MSI: Initialize msi_desc.nvec_used earlier to simplify code
> Simplify PCI MSI code by initializing msi_desc.nvec_used and
> msi_desc.msi_attrib.mutiple when create MSI descriptors.
multiple
when creating
> Also remove redundant checks in IRQ remapping drivers, PCI MSI core
> already guarattees these.
guarantees
> Signed-off-by: Jiang Liu <jiang....@linux.intel.com>
Acked-by: Bjorn Helgaas <bhelg...@google.com>
> ---
> drivers/iommu/irq_remapping.c | 8 --------
> drivers/pci/msi.c | 40 +++++++++++++++-------------------------
> 2 files changed, 15 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/iommu/irq_remapping.c b/drivers/iommu/irq_remapping.c
> index 176ff4372b7d..32fe5b1322d0 100644
> --- a/drivers/iommu/irq_remapping.c
> +++ b/drivers/iommu/irq_remapping.c
> @@ -69,19 +69,13 @@ 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);
> @@ -109,8 +103,6 @@ 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 fb2ccb536324..afe974600c7d 100644
> --- a/drivers/pci/msi.c
> +++ b/drivers/pci/msi.c
> @@ -85,19 +85,13 @@ 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)
> @@ -353,19 +347,12 @@ 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);
>
> @@ -556,7 +543,7 @@ 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;
> @@ -574,6 +561,8 @@ 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;
> @@ -606,7 +595,7 @@ 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;
>
> @@ -677,6 +666,7 @@ 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);
> }
> --
> 1.7.10.4
>
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