Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757731Ab3CFLWM (ORCPT ); Wed, 6 Mar 2013 06:22:12 -0500 Received: from mx1.redhat.com ([209.132.183.28]:10941 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757389Ab3CFLWG (ORCPT ); Wed, 6 Mar 2013 06:22:06 -0500 Date: Wed, 6 Mar 2013 12:26:47 +0100 From: Alexander Gordeev To: Jeff Garzik Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org Subject: [PATCH RFC 1/1] AHCI: Optimize interrupt processing Message-ID: <7aaa7f37e742bf57e3043be865774b8a1f033d86.1362568800.git.agordeev@redhat.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11983 Lines: 373 Split interrupt service routine into hardware context handler and threaded context handler. That allows to protect ports with individual locks rather than with a single host-wide lock, which results in better parallelism. Signed-off-by: Alexander Gordeev --- drivers/ata/acard-ahci.c | 8 ++--- drivers/ata/ahci.c | 54 ++++++++++++++++++------------- drivers/ata/ahci.h | 10 +++-- drivers/ata/ahci_platform.c | 3 +- drivers/ata/libahci.c | 74 +++++++++++++++++++++++++------------------ 5 files changed, 85 insertions(+), 64 deletions(-) diff --git a/drivers/ata/acard-ahci.c b/drivers/ata/acard-ahci.c index 4e94ba2..e429225 100644 --- a/drivers/ata/acard-ahci.c +++ b/drivers/ata/acard-ahci.c @@ -409,7 +409,7 @@ static int acard_ahci_init_one(struct pci_dev *pdev, const struct pci_device_id struct device *dev = &pdev->dev; struct ahci_host_priv *hpriv; struct ata_host *host; - int n_ports, i, rc; + int n_ports, n_msis, i, rc; VPRINTK("ENTER\n"); @@ -436,8 +436,7 @@ static int acard_ahci_init_one(struct pci_dev *pdev, const struct pci_device_id return -ENOMEM; hpriv->flags |= (unsigned long)pi.private_data; - if (!(hpriv->flags & AHCI_HFLAG_NO_MSI)) - pci_enable_msi(pdev); + n_msis = ahci_init_interrupts(pdev, hpriv); hpriv->mmio = pcim_iomap_table(pdev)[AHCI_PCI_BAR]; @@ -499,8 +498,7 @@ static int acard_ahci_init_one(struct pci_dev *pdev, const struct pci_device_id acard_ahci_pci_print_info(host); pci_set_master(pdev); - return ata_host_activate(host, pdev->irq, ahci_interrupt, IRQF_SHARED, - &acard_ahci_sht); + return ahci_host_activate(host, pdev->irq, n_msis, &acard_ahci_sht); } module_pci_driver(acard_ahci_pci_driver); diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c index 29ed8a8..7ab3173 100644 --- a/drivers/ata/ahci.c +++ b/drivers/ata/ahci.c @@ -1080,14 +1080,14 @@ int ahci_init_interrupts(struct pci_dev *pdev, struct ahci_host_priv *hpriv) pci_intx(pdev, 1); return 0; } +EXPORT_SYMBOL_GPL(ahci_init_interrupts); /** * ahci_host_activate - start AHCI host, request IRQs and register it * @host: target ATA host * @irq: base IRQ number to request * @n_msis: number of MSIs allocated for this host - * @irq_handler: irq_handler used when requesting IRQs - * @irq_flags: irq_flags used when requesting IRQs + * @sht: scsi_host_template to use when registering the host * * Similar to ata_host_activate, but requests IRQs according to AHCI-1.1 * when multiple MSIs were allocated. That is one MSI per port, starting @@ -1099,43 +1099,59 @@ int ahci_init_interrupts(struct pci_dev *pdev, struct ahci_host_priv *hpriv) * RETURNS: * 0 on success, -errno otherwise. */ -int ahci_host_activate(struct ata_host *host, int irq, unsigned int n_msis) +int ahci_host_activate(struct ata_host *host, int irq, unsigned int n_msis, + struct scsi_host_template *sht) { int i, rc; - - /* Sharing Last Message among several ports is not supported */ - if (n_msis < host->n_ports) - return -EINVAL; + unsigned int n_irqs; rc = ata_host_start(host); if (rc) return rc; - for (i = 0; i < host->n_ports; i++) { - rc = devm_request_threaded_irq(host->dev, - irq + i, ahci_hw_interrupt, ahci_thread_fn, IRQF_SHARED, - dev_driver_string(host->dev), host->ports[i]); + n_irqs = min(host->n_ports, n_msis); + n_irqs = max(n_irqs, 1u); + + if (n_irqs > 1) { + /* Sharing Last Message among several ports is not supported */ + if (n_irqs < host->n_ports) + return -EINVAL; + + for (i = 0; i < n_irqs; i++) { + rc = devm_request_threaded_irq(host->dev, irq + i, + ahci_multi_irqs_intr, ahci_port_thread_fn, + IRQF_SHARED, dev_driver_string(host->dev), + host->ports[i]); + if (rc) + goto out_free_irqs; + } + } else { + rc = devm_request_threaded_irq(host->dev, irq, + ahci_single_irq_intr, ahci_thread_fn, IRQF_SHARED, + dev_driver_string(host->dev), host); if (rc) - goto out_free_irqs; + goto out; } - for (i = 0; i < host->n_ports; i++) + for (i = 0; i < n_irqs; i++) ata_port_desc(host->ports[i], "irq %d", irq + i); - rc = ata_host_register(host, &ahci_sht); + rc = ata_host_register(host, sht); if (rc) goto out_free_all_irqs; return 0; out_free_all_irqs: - i = host->n_ports; + i = n_irqs; out_free_irqs: for (i--; i >= 0; i--) devm_free_irq(host->dev, irq + i, host->ports[i]); +out: return rc; } +EXPORT_SYMBOL_GPL(ahci_host_activate); static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) { @@ -1233,8 +1249,6 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) hpriv->mmio = pcim_iomap_table(pdev)[ahci_pci_bar]; n_msis = ahci_init_interrupts(pdev, hpriv); - if (n_msis > 1) - hpriv->flags |= AHCI_HFLAG_MULTI_MSI; /* save initial config */ ahci_pci_save_initial_config(pdev, hpriv); @@ -1332,11 +1346,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) pci_set_master(pdev); - if (hpriv->flags & AHCI_HFLAG_MULTI_MSI) - return ahci_host_activate(host, pdev->irq, n_msis); - - return ata_host_activate(host, pdev->irq, ahci_interrupt, IRQF_SHARED, - &ahci_sht); + return ahci_host_activate(host, pdev->irq, n_msis, &ahci_sht); } module_pci_driver(ahci_pci_driver); diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h index 3ed76cc..0172bbd 100644 --- a/drivers/ata/ahci.h +++ b/drivers/ata/ahci.h @@ -216,7 +216,6 @@ enum { AHCI_HFLAG_DELAY_ENGINE = (1 << 15), /* do not start engine on port start (wait until error-handling stage) */ - AHCI_HFLAG_MULTI_MSI = (1 << 16), /* multiple PCI MSIs */ /* ap->flags bits */ @@ -345,11 +344,14 @@ int ahci_port_resume(struct ata_port *ap); void ahci_set_em_messages(struct ahci_host_priv *hpriv, struct ata_port_info *pi); int ahci_reset_em(struct ata_host *host); -irqreturn_t ahci_interrupt(int irq, void *dev_instance); -irqreturn_t ahci_hw_interrupt(int irq, void *dev_instance); +irqreturn_t ahci_single_irq_intr(int irq, void *dev_instance); +irqreturn_t ahci_multi_irqs_intr(int irq, void *dev_instance); irqreturn_t ahci_thread_fn(int irq, void *dev_instance); +irqreturn_t ahci_port_thread_fn(int irq, void *dev_instance); void ahci_print_info(struct ata_host *host, const char *scc_s); -int ahci_host_activate(struct ata_host *host, int irq, unsigned int n_msis); +int ahci_host_activate(struct ata_host *host, int irq, unsigned int n_msis, + struct scsi_host_template *sht); +int ahci_init_interrupts(struct pci_dev *pdev, struct ahci_host_priv *hpriv); static inline void __iomem *__ahci_port_base(struct ata_host *host, unsigned int port_no) diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c index 09728e0..9c1f485 100644 --- a/drivers/ata/ahci_platform.c +++ b/drivers/ata/ahci_platform.c @@ -188,8 +188,7 @@ static int __init ahci_probe(struct platform_device *pdev) ahci_init_controller(host); ahci_print_info(host, "platform"); - rc = ata_host_activate(host, irq, ahci_interrupt, IRQF_SHARED, - &ahci_platform_sht); + rc = ahci_host_activate(host, irq, 0, &ahci_platform_sht); if (rc) goto err0; diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c index 3b54e84..6b8977c 100644 --- a/drivers/ata/libahci.c +++ b/drivers/ata/libahci.c @@ -1639,9 +1639,9 @@ static void ahci_error_intr(struct ata_port *ap, u32 irq_stat) ata_port_abort(ap); } -static void ahci_handle_port_interrupt(struct ata_port *ap, - void __iomem *port_mmio, u32 status) +static void ahci_handle_port_interrupt(struct ata_port *ap, u32 status) { + void __iomem *port_mmio = ahci_port_base(ap); struct ata_eh_info *ehi = &ap->link.eh_info; struct ahci_port_priv *pp = ap->private_data; struct ahci_host_priv *hpriv = ap->host->private_data; @@ -1724,22 +1724,10 @@ static void ahci_handle_port_interrupt(struct ata_port *ap, } } -void ahci_port_intr(struct ata_port *ap) -{ - void __iomem *port_mmio = ahci_port_base(ap); - u32 status; - - status = readl(port_mmio + PORT_IRQ_STAT); - writel(status, port_mmio + PORT_IRQ_STAT); - - ahci_handle_port_interrupt(ap, port_mmio, status); -} - -irqreturn_t ahci_thread_fn(int irq, void *dev_instance) +irqreturn_t ahci_port_thread_fn(int irq, void *dev_instance) { struct ata_port *ap = dev_instance; struct ahci_port_priv *pp = ap->private_data; - void __iomem *port_mmio = ahci_port_base(ap); unsigned long flags; u32 status; @@ -1750,14 +1738,43 @@ irqreturn_t ahci_thread_fn(int irq, void *dev_instance) spin_unlock_irqrestore(&ap->host->lock, flags); spin_lock_bh(ap->lock); - ahci_handle_port_interrupt(ap, port_mmio, status); + ahci_handle_port_interrupt(ap, status); spin_unlock_bh(ap->lock); return IRQ_HANDLED; } +EXPORT_SYMBOL_GPL(ahci_port_thread_fn); + +irqreturn_t ahci_thread_fn(int irq, void *dev_instance) +{ + struct ata_host *host = dev_instance; + struct ahci_host_priv *hpriv = host->private_data; + u32 irq_masked = hpriv->port_map; + unsigned int i; + + for (i = 0; i < host->n_ports; i++) { + struct ata_port *ap; + + if (!(irq_masked & (1 << i))) + continue; + + ap = host->ports[i]; + if (ap) { + ahci_port_thread_fn(irq, ap); + VPRINTK("port %u\n", i); + } else { + VPRINTK("port %u (no irq)\n", i); + if (ata_ratelimit()) + dev_warn(host->dev, + "interrupt on disabled port %u\n", i); + } + } + + return IRQ_HANDLED; +} EXPORT_SYMBOL_GPL(ahci_thread_fn); -void ahci_hw_port_interrupt(struct ata_port *ap) +void ahci_update_intr_status(struct ata_port *ap) { void __iomem *port_mmio = ahci_port_base(ap); struct ahci_port_priv *pp = ap->private_data; @@ -1769,7 +1786,7 @@ void ahci_hw_port_interrupt(struct ata_port *ap) pp->intr_status |= status; } -irqreturn_t ahci_hw_interrupt(int irq, void *dev_instance) +irqreturn_t ahci_multi_irqs_intr(int irq, void *dev_instance) { struct ata_port *ap_this = dev_instance; struct ahci_port_priv *pp = ap_this->private_data; @@ -1805,7 +1822,7 @@ irqreturn_t ahci_hw_interrupt(int irq, void *dev_instance) ap = host->ports[i]; if (ap) { - ahci_hw_port_interrupt(ap); + ahci_update_intr_status(ap); VPRINTK("port %u\n", i); } else { VPRINTK("port %u (no irq)\n", i); @@ -1823,9 +1840,9 @@ irqreturn_t ahci_hw_interrupt(int irq, void *dev_instance) return IRQ_WAKE_THREAD; } -EXPORT_SYMBOL_GPL(ahci_hw_interrupt); +EXPORT_SYMBOL_GPL(ahci_multi_irqs_intr); -irqreturn_t ahci_interrupt(int irq, void *dev_instance) +irqreturn_t ahci_single_irq_intr(int irq, void *dev_instance) { struct ata_host *host = dev_instance; struct ahci_host_priv *hpriv; @@ -1855,7 +1872,7 @@ irqreturn_t ahci_interrupt(int irq, void *dev_instance) ap = host->ports[i]; if (ap) { - ahci_port_intr(ap); + ahci_update_intr_status(ap); VPRINTK("port %u\n", i); } else { VPRINTK("port %u (no irq)\n", i); @@ -1882,9 +1899,9 @@ irqreturn_t ahci_interrupt(int irq, void *dev_instance) VPRINTK("EXIT\n"); - return IRQ_RETVAL(handled); + return handled ? IRQ_WAKE_THREAD : IRQ_NONE; } -EXPORT_SYMBOL_GPL(ahci_interrupt); +EXPORT_SYMBOL_GPL(ahci_single_irq_intr); static unsigned int ahci_qc_issue(struct ata_queued_cmd *qc) { @@ -2203,13 +2220,8 @@ static int ahci_port_start(struct ata_port *ap) */ pp->intr_mask = DEF_PORT_IRQ; - /* - * Switch to per-port locking in case each port has its own MSI vector. - */ - if ((hpriv->flags & AHCI_HFLAG_MULTI_MSI)) { - spin_lock_init(&pp->lock); - ap->lock = &pp->lock; - } + spin_lock_init(&pp->lock); + ap->lock = &pp->lock; ap->private_data = pp; -- 1.7.7.6 -- Regards, Alexander Gordeev agordeev@redhat.com -- 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/