Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761111AbYGKBD1 (ORCPT ); Thu, 10 Jul 2008 21:03:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759373AbYGKBCm (ORCPT ); Thu, 10 Jul 2008 21:02:42 -0400 Received: from mail.tor.primus.ca ([216.254.136.21]:43098 "EHLO mail-08.primus.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758013AbYGKBCg (ORCPT ); Thu, 10 Jul 2008 21:02:36 -0400 From: Matthew Wilcox To: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Cc: grundler@parisc-linux.org, mingo@elte.hu, tglx@linutronix.de, jgarzik@pobox.com, linux-ide@vger.kernel.org, suresh.b.siddha@intel.com, benh@kernel.crashing.org, jbarnes@virtuousgeek.org, rdunlap@xenotime.net, mtk.manpages@gmail.com, Matthew Wilcox , Matthew Wilcox Subject: [PATCH] AHCI: Request multiple MSIs Date: Thu, 10 Jul 2008 21:00:01 -0400 Message-Id: <1215738002-4961-4-git-send-email-matthew@wil.cx> X-Mailer: git-send-email 1.5.5.4 In-Reply-To: <20080711005719.GO14894@parisc-linux.org> References: <20080711005719.GO14894@parisc-linux.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4847 Lines: 183 AHCI controllers can support up to 16 interrupts, one per port. This saves us a readl() in the interrupt path to determine which port has generated the interrupt. Signed-off-by: Matthew Wilcox --- drivers/ata/ahci.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++-- 1 files changed, 122 insertions(+), 5 deletions(-) diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 5e6468a..12562fc 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -102,6 +102,7 @@ enum { /* HOST_CTL bits */ HOST_RESET = (1 << 0), /* reset controller; self-clear */ HOST_IRQ_EN = (1 << 1), /* global IRQ enable */ + HOST_MSI_RSM = (1 << 2), /* Revert to Single Message */ HOST_AHCI_EN = (1 << 31), /* AHCI enabled */ /* HOST_CAP bits */ @@ -1771,6 +1772,15 @@ static void ahci_port_intr(struct ata_port *ap) } } +static irqreturn_t ahci_msi_interrupt(int irq, void *dev_instance) +{ + struct ata_port *ap = dev_instance; + spin_lock(&ap->host->lock); + ahci_port_intr(ap); + spin_unlock(&ap->host->lock); + return IRQ_HANDLED; +} + static irqreturn_t ahci_interrupt(int irq, void *dev_instance) { struct ata_host *host = dev_instance; @@ -2220,6 +2230,107 @@ static void ahci_p5wdh_workaround(struct ata_host *host) } } +static int ahci_request_irqs(struct pci_dev *pdev, struct ata_host *host, + int n_irqs) +{ + int i, rc; + + if (n_irqs > host->n_ports) { + n_irqs = host->n_ports; + } else if (n_irqs < host->n_ports || n_irqs == 1) { + n_irqs--; + rc = devm_request_irq(host->dev, pdev->irq + n_irqs, + ahci_interrupt, + IRQF_SHARED | (n_irqs ? IRQF_DISABLED : 0), + dev_driver_string(host->dev), host); + if (rc) + return rc; + } + + for (i = 0; i < n_irqs; i++) { + rc = devm_request_irq(host->dev, pdev->irq + i, + ahci_msi_interrupt, IRQF_DISABLED, + dev_driver_string(host->dev), host->ports[i]); + if (rc) + goto free_irqs; + } + + return 0; + + free_irqs: + if (n_irqs < host->n_ports) + devm_free_irq(host->dev, pdev->irq + n_irqs, host); + while (i >= 0) + devm_free_irq(host->dev, pdev->irq + i, host->ports[i]); + return rc; +} + +static int ahci_setup_irq_block(struct pci_dev *pdev, struct ata_host *host, + int n_irqs) +{ + int rc; + + rc = pci_enable_msi_block(pdev, n_irqs); + if (rc) + return rc; + if (n_irqs > 1) { + void __iomem *mmio = host->iomap[AHCI_PCI_BAR]; + u32 host_ctl = readl(mmio + HOST_CTL); + if (host_ctl & HOST_MSI_RSM) + goto try_different; + } + + rc = ahci_request_irqs(pdev, host, n_irqs); + if (!rc) + return 0; + + try_different: + pci_disable_msi(pdev); + pci_intx(pdev, 1); + return (n_irqs == 1) ? rc : 1; +} + +static int ahci_setup_irqs(struct pci_dev *pdev, struct ata_host *host) +{ + struct ahci_host_priv *hpriv = host->private_data; + int n_irqs, pos, rc; + u16 control; + + if (hpriv->flags & AHCI_HFLAG_NO_MSI) + goto no_msi; + + /* + * We only need one interrupt per port (plus one for CCC which + * isn't supported yet), but some AHCI controllers refuse to use + * multiple MSIs unless they get the maximum number of interrupts + */ + + rc = ahci_setup_irq_block(pdev, host, host->n_ports); + if (rc == 0) + return 0; + if (rc < 0) + goto no_msi; + + /* Find out how many it might want */ + pos = pci_find_capability(pdev, PCI_CAP_ID_MSI); + pci_read_config_word(pdev, pos + PCI_MSI_FLAGS, &control); + n_irqs = 1 << ((control & PCI_MSI_FLAGS_QMASK) >> 1); + + for (;;) { + rc = ahci_setup_irq_block(pdev, host, n_irqs); + if (rc == 0) + return 0; + if (rc < 0) + goto no_msi; + n_irqs = rc; + } + + return 0; + + no_msi: + return ahci_request_irqs(pdev, host, 1); +} + static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) { static int printed_version; @@ -2278,9 +2389,6 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) (pdev->revision == 0xa1 || pdev->revision == 0xa2)) hpriv->flags |= AHCI_HFLAG_NO_MSI; - if ((hpriv->flags & AHCI_HFLAG_NO_MSI) || pci_enable_msi(pdev)) - pci_intx(pdev, 1); - /* save initial config */ ahci_save_initial_config(pdev, hpriv); @@ -2335,8 +2443,17 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) ahci_print_info(host); pci_set_master(pdev); - return ata_host_activate(host, pdev->irq, ahci_interrupt, IRQF_SHARED, - &ahci_sht); + + rc = ata_host_start(host); + if (rc) + return rc; + + rc = ahci_setup_irqs(pdev, host); + if (rc) + return rc; + + rc = ata_host_register(host, &ahci_sht); + return rc; } static int __init ahci_init(void) -- 1.5.5.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/