From 9c8313343c83c0ca731ceb8d2a4ab1e022ed9c94 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Wed, 18 Apr 2007 19:39:21 +1000 Subject: [PATCH] MSI: Give archs the option to allocate all MSI/Xs at once. This patch introduces an optional function, arch_setup_msi_irqs(), (note the plural) which gives an arch the opportunity to do per-device setup for MSI/X and then allocate all the requested MSI/Xs at once. If that's not required by the arch, the default version simply calls arch_setup_msi_irq() for each MSI irq required. arch_setup_msi_irqs() is passed a pdev, attached to the pdev is a list of msi_descs with irq == 0, it is up to the arch to connect these up to an irq (via set_irq_msi()) or return an error. For convenience the number of vectors and the type are passed also. All msi_descs with irq != 0 are considered allocated, and the arch teardown routine will be called on them when necessary. The existing semantics of pci_enable_msix() are that if the requested number of irqs can not be allocated, the maximum number that _could_ be allocated is returned. To support that, we define that in case of an error from arch_setup_msi_irqs(), the number of msi_descs with irq != 0 are considered allocated, and are counted toward the "max that could be allocated". Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- drivers/pci/msi.c | 63 +++++++++++++++++++++++++++++++-------------- include/linux/msi.h | 1 + 2 files changed, 45 insertions(+), 19 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 88362f1bd9..c71e8e4c71 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -334,13 +334,15 @@ static int msi_capability_init(struct pci_dev *dev) msi_mask_bits_reg(pos, is_64bit_address(control)), maskbits); } + list_add(&entry->list, &dev->msi_list); + /* Configure MSI capability structure */ - ret = arch_setup_msi_irq(dev, entry); + ret = arch_setup_msi_irqs(dev, 1, PCI_CAP_ID_MSI); if (ret) { + list_del(&entry->list); kfree(entry); return ret; } - list_add(&entry->list, &dev->msi_list); /* Set MSI enabled bits */ pci_intx(dev, 0); /* disable intx */ @@ -365,7 +367,7 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries, int nvec) { struct msi_desc *entry; - int irq, pos, i, j, nr_entries, ret; + int pos, i, j, nr_entries, ret; unsigned long phys_addr; u32 table_offset; u16 control; @@ -404,30 +406,33 @@ static int msix_capability_init(struct pci_dev *dev, entry->dev = dev; entry->mask_base = base; - /* Configure MSI-X capability structure */ - ret = arch_setup_msi_irq(dev, entry); - if (ret) { - kfree(entry); - break; - } - entries[i].vector = entry->irq; list_add(&entry->list, &dev->msi_list); } - if (i != nvec) { - int avail = i - 1; - i--; - for (; i >= 0; i--) { - irq = (entries + i)->vector; - msi_free_irq(dev, irq); - (entries + i)->vector = 0; + + ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSIX); + if (ret) { + int avail = 0; + list_for_each_entry(entry, &dev->msi_list, list) { + if (entry->irq != 0) { + avail++; + msi_free_irq(dev, entry->irq); + } } + /* If we had some success report the number of irqs * we succeeded in setting up. */ - if (avail <= 0) - avail = -EBUSY; + if (avail == 0) + avail = ret; return avail; } + + i = 0; + list_for_each_entry(entry, &dev->msi_list, list) { + entries[i].vector = entry->irq; + set_irq_msi(entry->irq, entry); + i++; + } /* Set MSI-X enabled bits */ pci_intx(dev, 0); /* disable intx */ msix_set_enable(dev, 1); @@ -694,3 +699,23 @@ arch_msi_check_device(struct pci_dev* dev, int nvec, int type) return 0; } +int __attribute__ ((weak)) +arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *entry) +{ + return 0; +} + +int __attribute__ ((weak)) +arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type) +{ + struct msi_desc *entry; + int ret; + + list_for_each_entry(entry, &dev->msi_list, list) { + ret = arch_setup_msi_irq(dev, entry); + if (ret) + return ret; + } + + return 0; +} diff --git a/include/linux/msi.h b/include/linux/msi.h index 931e013f1d..494627ae02 100644 --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -41,6 +41,7 @@ struct msi_desc { */ int arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc); void arch_teardown_msi_irq(unsigned int irq); +extern int arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type); extern int arch_msi_check_device(struct pci_dev* dev, int nvec, int type); -- 2.39.5