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authorAlexander Gordeev <agordeev@redhat.com>2012-11-19 16:02:48 +0100
committerIngo Molnar <mingo@kernel.org>2013-01-24 17:25:13 +0100
commit5ca72c4f7c412c2002363218901eba5516c476b1 (patch)
treec87592b1249a5fa97e8e4cd62e1e72d9b6db389e /drivers/ata/libahci.c
parent08261d87f7d1b6253ab3223756625a5c74532293 (diff)
downloadlinux-5ca72c4f7c412c2002363218901eba5516c476b1.tar.bz2
AHCI: Support multiple MSIs
Take advantage of multiple MSIs implementation on x86 - on systems with IRQ remapping AHCI ports not only get assigned separate MSI vectors - but also separate IRQs. As result, interrupts generated by different ports could be serviced on different CPUs rather than on a single one. In cases when number of allocated MSIs is less than requested the Sharing Last MSI mode does not get used, no matter implemented in hardware or not. Instead, the driver assumes the advantage of multiple MSIs is negated and falls back to the single MSI mode as if MRSM bit was set (some Intel chips implement this strategy anyway - MRSM bit gets set even if the number of allocated MSIs exceeds the number of implemented ports). Signed-off-by: Alexander Gordeev <agordeev@redhat.com> Acked-by: Jeff Garzik <jgarzik@redhat.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/15bf7ee314dd55f21ec7d2a01c47613cd8190a7c.1353324359.git.agordeev@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'drivers/ata/libahci.c')
-rw-r--r--drivers/ata/libahci.c118
1 files changed, 112 insertions, 6 deletions
diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index 6cd7805e47ca..34c82167b962 100644
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1655,19 +1655,16 @@ static void ahci_error_intr(struct ata_port *ap, u32 irq_stat)
ata_port_abort(ap);
}
-static void ahci_port_intr(struct ata_port *ap)
+static void ahci_handle_port_interrupt(struct ata_port *ap,
+ void __iomem *port_mmio, 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;
int resetting = !!(ap->pflags & ATA_PFLAG_RESETTING);
- u32 status, qc_active = 0;
+ u32 qc_active = 0;
int rc;
- status = readl(port_mmio + PORT_IRQ_STAT);
- writel(status, port_mmio + PORT_IRQ_STAT);
-
/* ignore BAD_PMP while resetting */
if (unlikely(resetting))
status &= ~PORT_IRQ_BAD_PMP;
@@ -1743,6 +1740,107 @@ static void ahci_port_intr(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)
+{
+ 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;
+
+ spin_lock_irqsave(&ap->host->lock, flags);
+ status = pp->intr_status;
+ if (status)
+ pp->intr_status = 0;
+ spin_unlock_irqrestore(&ap->host->lock, flags);
+
+ spin_lock_bh(ap->lock);
+ ahci_handle_port_interrupt(ap, port_mmio, status);
+ spin_unlock_bh(ap->lock);
+
+ return IRQ_HANDLED;
+}
+EXPORT_SYMBOL_GPL(ahci_thread_fn);
+
+void ahci_hw_port_interrupt(struct ata_port *ap)
+{
+ void __iomem *port_mmio = ahci_port_base(ap);
+ struct ahci_port_priv *pp = ap->private_data;
+ u32 status;
+
+ status = readl(port_mmio + PORT_IRQ_STAT);
+ writel(status, port_mmio + PORT_IRQ_STAT);
+
+ pp->intr_status |= status;
+}
+
+irqreturn_t ahci_hw_interrupt(int irq, void *dev_instance)
+{
+ struct ata_port *ap_this = dev_instance;
+ struct ahci_port_priv *pp = ap_this->private_data;
+ struct ata_host *host = ap_this->host;
+ struct ahci_host_priv *hpriv = host->private_data;
+ void __iomem *mmio = hpriv->mmio;
+ unsigned int i;
+ u32 irq_stat, irq_masked;
+
+ VPRINTK("ENTER\n");
+
+ spin_lock(&host->lock);
+
+ irq_stat = readl(mmio + HOST_IRQ_STAT);
+
+ if (!irq_stat) {
+ u32 status = pp->intr_status;
+
+ spin_unlock(&host->lock);
+
+ VPRINTK("EXIT\n");
+
+ return status ? IRQ_WAKE_THREAD : IRQ_NONE;
+ }
+
+ irq_masked = irq_stat & hpriv->port_map;
+
+ 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_hw_port_interrupt(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);
+ }
+ }
+
+ writel(irq_stat, mmio + HOST_IRQ_STAT);
+
+ spin_unlock(&host->lock);
+
+ VPRINTK("EXIT\n");
+
+ return IRQ_WAKE_THREAD;
+}
+EXPORT_SYMBOL_GPL(ahci_hw_interrupt);
+
irqreturn_t ahci_interrupt(int irq, void *dev_instance)
{
struct ata_host *host = dev_instance;
@@ -2196,6 +2294,14 @@ 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;
+ }
+
ap->private_data = pp;
/* engage engines, captain */