From 7bd007e480672c99d8656c7b7b12ef0549432c37 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 4 Oct 2006 02:16:31 -0700 Subject: [PATCH] [PATCH] genirq: msi: simplify msi enable and disable The problem. Because the disable routines leave the msi interrupts in all sorts of half enabled states the enable routines become impossible to implement correctly, and almost impossible to understand. Simplifing this allows me to simply kill the buggy reroute_msix_table, and generally makes the code more maintainable. Signed-off-by: Eric W. Biederman Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Benjamin Herrenschmidt Cc: Rajesh Shah Cc: Andi Kleen Cc: "Protasevich, Natalie" Cc: "Luck, Tony" Cc: Rajesh Shah Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/pci/msi.c | 122 +++++++----------------------------------------------- 1 file changed, 16 insertions(+), 106 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 27a0574..75d1c0d 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -933,7 +933,6 @@ int pci_msi_supported(struct pci_dev * dev) int pci_enable_msi(struct pci_dev* dev) { int pos, temp, status; - u16 control; if (pci_msi_supported(dev) < 0) return -EINVAL; @@ -948,27 +947,8 @@ int pci_enable_msi(struct pci_dev* dev) if (!pos) return -EINVAL; - if (!msi_lookup_vector(dev, PCI_CAP_ID_MSI)) { - /* Lookup Sucess */ - unsigned long flags; + WARN_ON(!msi_lookup_vector(dev, PCI_CAP_ID_MSI)); - pci_read_config_word(dev, msi_control_reg(pos), &control); - if (control & PCI_MSI_FLAGS_ENABLE) - return 0; /* Already in MSI mode */ - spin_lock_irqsave(&msi_lock, flags); - if (!vector_irq[dev->irq]) { - msi_desc[dev->irq]->msi_attrib.state = 0; - vector_irq[dev->irq] = -1; - nr_released_vectors--; - spin_unlock_irqrestore(&msi_lock, flags); - status = msi_register_init(dev, msi_desc[dev->irq]); - if (status == 0) - enable_msi_mode(dev, pos, PCI_CAP_ID_MSI); - return status; - } - spin_unlock_irqrestore(&msi_lock, flags); - dev->irq = temp; - } /* Check whether driver already requested for MSI-X vectors */ pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); if (pos > 0 && !msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) { @@ -1010,6 +990,8 @@ void pci_disable_msi(struct pci_dev* dev) if (!(control & PCI_MSI_FLAGS_ENABLE)) return; + disable_msi_mode(dev, pos, PCI_CAP_ID_MSI); + spin_lock_irqsave(&msi_lock, flags); entry = msi_desc[dev->irq]; if (!entry || !entry->dev || entry->msi_attrib.type != PCI_CAP_ID_MSI) { @@ -1023,14 +1005,12 @@ void pci_disable_msi(struct pci_dev* dev) pci_name(dev), dev->irq); BUG_ON(entry->msi_attrib.state > 0); } else { - vector_irq[dev->irq] = 0; /* free it */ - nr_released_vectors++; default_vector = entry->msi_attrib.default_vector; spin_unlock_irqrestore(&msi_lock, flags); + msi_free_vector(dev, dev->irq, 0); + /* Restore dev->irq to its default pin-assertion vector */ dev->irq = default_vector; - disable_msi_mode(dev, pci_find_capability(dev, PCI_CAP_ID_MSI), - PCI_CAP_ID_MSI); } } @@ -1078,57 +1058,6 @@ static int msi_free_vector(struct pci_dev* dev, int vector, int reassign) return 0; } -static int reroute_msix_table(int head, struct msix_entry *entries, int *nvec) -{ - int vector = head, tail = 0; - int i, j = 0, nr_entries = 0; - void __iomem *base; - unsigned long flags; - - spin_lock_irqsave(&msi_lock, flags); - while (head != tail) { - nr_entries++; - tail = msi_desc[vector]->link.tail; - if (entries[0].entry == msi_desc[vector]->msi_attrib.entry_nr) - j = vector; - vector = tail; - } - if (*nvec > nr_entries) { - spin_unlock_irqrestore(&msi_lock, flags); - *nvec = nr_entries; - return -EINVAL; - } - vector = ((j > 0) ? j : head); - for (i = 0; i < *nvec; i++) { - j = msi_desc[vector]->msi_attrib.entry_nr; - msi_desc[vector]->msi_attrib.state = 0; /* Mark it not active */ - vector_irq[vector] = -1; /* Mark it busy */ - nr_released_vectors--; - entries[i].vector = vector; - if (j != (entries + i)->entry) { - base = msi_desc[vector]->mask_base; - msi_desc[vector]->msi_attrib.entry_nr = - (entries + i)->entry; - writel( readl(base + j * PCI_MSIX_ENTRY_SIZE + - PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET), base + - (entries + i)->entry * PCI_MSIX_ENTRY_SIZE + - PCI_MSIX_ENTRY_LOWER_ADDR_OFFSET); - writel( readl(base + j * PCI_MSIX_ENTRY_SIZE + - PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET), base + - (entries + i)->entry * PCI_MSIX_ENTRY_SIZE + - PCI_MSIX_ENTRY_UPPER_ADDR_OFFSET); - writel( (readl(base + j * PCI_MSIX_ENTRY_SIZE + - PCI_MSIX_ENTRY_DATA_OFFSET) & 0xff00) | vector, - base + (entries+i)->entry*PCI_MSIX_ENTRY_SIZE + - PCI_MSIX_ENTRY_DATA_OFFSET); - } - vector = msi_desc[vector]->link.tail; - } - spin_unlock_irqrestore(&msi_lock, flags); - - return 0; -} - /** * pci_enable_msix - configure device's MSI-X capability structure * @dev: pointer to the pci_dev data structure of MSI-X device function @@ -1163,9 +1092,6 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) return -EINVAL; pci_read_config_word(dev, msi_control_reg(pos), &control); - if (control & PCI_MSIX_FLAGS_ENABLE) - return -EINVAL; /* Already in MSI-X mode */ - nr_entries = multi_msix_capable(control); if (nvec > nr_entries) return -EINVAL; @@ -1180,19 +1106,8 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) } } temp = dev->irq; - if (!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) { - /* Lookup Sucess */ - nr_entries = nvec; - /* Reroute MSI-X table */ - if (reroute_msix_table(dev->irq, entries, &nr_entries)) { - /* #requested > #previous-assigned */ - dev->irq = temp; - return nr_entries; - } - dev->irq = temp; - enable_msi_mode(dev, pos, PCI_CAP_ID_MSIX); - return 0; - } + WARN_ON(!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)); + /* Check whether driver already requested for MSI vector */ if (pci_find_capability(dev, PCI_CAP_ID_MSI) > 0 && !msi_lookup_vector(dev, PCI_CAP_ID_MSI)) { @@ -1251,37 +1166,32 @@ void pci_disable_msix(struct pci_dev* dev) if (!(control & PCI_MSIX_FLAGS_ENABLE)) return; + disable_msi_mode(dev, pos, PCI_CAP_ID_MSIX); + temp = dev->irq; if (!msi_lookup_vector(dev, PCI_CAP_ID_MSIX)) { int state, vector, head, tail = 0, warning = 0; unsigned long flags; vector = head = dev->irq; - spin_lock_irqsave(&msi_lock, flags); + dev->irq = temp; /* Restore pin IRQ */ while (head != tail) { + spin_lock_irqsave(&msi_lock, flags); state = msi_desc[vector]->msi_attrib.state; + tail = msi_desc[vector]->link.tail; + spin_unlock_irqrestore(&msi_lock, flags); if (state) warning = 1; - else { - vector_irq[vector] = 0; /* free it */ - nr_released_vectors++; - } - tail = msi_desc[vector]->link.tail; + else if (vector != head) /* Release MSI-X vector */ + msi_free_vector(dev, vector, 0); vector = tail; } - spin_unlock_irqrestore(&msi_lock, flags); + msi_free_vector(dev, vector, 0); if (warning) { - dev->irq = temp; printk(KERN_WARNING "PCI: %s: pci_disable_msix() called without " "free_irq() on all MSI-X vectors\n", pci_name(dev)); BUG_ON(warning > 0); - } else { - dev->irq = temp; - disable_msi_mode(dev, - pci_find_capability(dev, PCI_CAP_ID_MSIX), - PCI_CAP_ID_MSIX); - } } } -- 2.7.4