Merge branch 'alpm' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev

* 'alpm' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  [libata] AHCI: add hw link power management support
  [libata] Link power management infrastructure

1 files changed, 155 insertions, 2 deletions

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index c8ab947cf359..ed9b407e42d4 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -49,6 +49,9 @@
 #define DRV_NAME        "ahci"
 #define DRV_VERSION     "3.0"
 
+static int ahci_enable_alpm(struct ata_port *ap,
+                enum link_pm policy);
+static void ahci_disable_alpm(struct ata_port *ap);
 
 enum {
         AHCI_PCI_BAR            = 5,
@@ -99,6 +102,7 @@ enum {
         HOST_CAP_SSC            = (1 << 14), /* Slumber capable */
         HOST_CAP_PMP            = (1 << 17), /* Port Multiplier support */
         HOST_CAP_CLO            = (1 << 24), /* Command List Override support */
+        HOST_CAP_ALPM           = (1 << 26), /* Aggressive Link PM support */
         HOST_CAP_SSS            = (1 << 27), /* Staggered Spin-up */
         HOST_CAP_SNTF           = (1 << 29), /* SNotification register */
         HOST_CAP_NCQ            = (1 << 30), /* Native Command Queueing */
@@ -155,6 +159,8 @@ enum {
                                   PORT_IRQ_PIOS_FIS | PORT_IRQ_D2H_REG_FIS,
 
         /* PORT_CMD bits */
+        PORT_CMD_ASP            = (1 << 27), /* Aggressive Slumber/Partial */
+        PORT_CMD_ALPE           = (1 << 26), /* Aggressive Link PM enable */
         PORT_CMD_ATAPI          = (1 << 24), /* Device is ATAPI */
         PORT_CMD_PMP            = (1 << 17), /* PMP attached */
         PORT_CMD_LIST_ON        = (1 << 15), /* cmd list DMA engine running */
@@ -178,13 +184,14 @@ enum {
         AHCI_HFLAG_MV_PATA              = (1 << 4), /* PATA port */
         AHCI_HFLAG_NO_MSI               = (1 << 5), /* no PCI MSI */
         AHCI_HFLAG_NO_PMP               = (1 << 6), /* no PMP */
+        AHCI_HFLAG_NO_HOTPLUG           = (1 << 7), /* ignore PxSERR.DIAG.N */
 
         /* ap->flags bits */
-        AHCI_FLAG_NO_HOTPLUG            = (1 << 24), /* ignore PxSERR.DIAG.N */
 
         AHCI_FLAG_COMMON                = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
                                           ATA_FLAG_MMIO | ATA_FLAG_PIO_DMA |
-                                          ATA_FLAG_ACPI_SATA | ATA_FLAG_AN,
+                                          ATA_FLAG_ACPI_SATA | ATA_FLAG_AN |
+                                          ATA_FLAG_IPM,
         AHCI_LFLAG_COMMON               = ATA_LFLAG_SKIP_D2H_BSY,
 };
 
@@ -254,6 +261,11 @@ static int ahci_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg);
 static int ahci_pci_device_resume(struct pci_dev *pdev);
 #endif
 
+static struct class_device_attribute *ahci_shost_attrs[] = {
+        &class_device_attr_link_power_management_policy,
+        NULL
+};
+
 static struct scsi_host_template ahci_sht = {
         .module                 = THIS_MODULE,
         .name                   = DRV_NAME,
@@ -271,6 +283,7 @@ static struct scsi_host_template ahci_sht = {
         .slave_configure        = ata_scsi_slave_config,
         .slave_destroy          = ata_scsi_slave_destroy,
         .bios_param             = ata_std_bios_param,
+        .shost_attrs            = ahci_shost_attrs,
 };
 
 static const struct ata_port_operations ahci_ops = {
@@ -302,6 +315,8 @@ static const struct ata_port_operations ahci_ops = {
         .port_suspend           = ahci_port_suspend,
         .port_resume            = ahci_port_resume,
 #endif
+        .enable_pm              = ahci_enable_alpm,
+        .disable_pm             = ahci_disable_alpm,
 
         .port_start             = ahci_port_start,
         .port_stop              = ahci_port_stop,
@@ -836,6 +851,130 @@ static void ahci_power_up(struct ata_port *ap)
         writel(cmd | PORT_CMD_ICC_ACTIVE, port_mmio + PORT_CMD);
 }
 
+static void ahci_disable_alpm(struct ata_port *ap)
+{
+        struct ahci_host_priv *hpriv = ap->host->private_data;
+        void __iomem *port_mmio = ahci_port_base(ap);
+        u32 cmd;
+        struct ahci_port_priv *pp = ap->private_data;
+
+        /* IPM bits should be disabled by libata-core */
+        /* get the existing command bits */
+        cmd = readl(port_mmio + PORT_CMD);
+
+        /* disable ALPM and ASP */
+        cmd &= ~PORT_CMD_ASP;
+        cmd &= ~PORT_CMD_ALPE;
+
+        /* force the interface back to active */
+        cmd |= PORT_CMD_ICC_ACTIVE;
+
+        /* write out new cmd value */
+        writel(cmd, port_mmio + PORT_CMD);
+        cmd = readl(port_mmio + PORT_CMD);
+
+        /* wait 10ms to be sure we've come out of any low power state */
+        msleep(10);
+
+        /* clear out any PhyRdy stuff from interrupt status */
+        writel(PORT_IRQ_PHYRDY, port_mmio + PORT_IRQ_STAT);
+
+        /* go ahead and clean out PhyRdy Change from Serror too */
+        ahci_scr_write(ap, SCR_ERROR, ((1 << 16) | (1 << 18)));
+
+        /*
+         * Clear flag to indicate that we should ignore all PhyRdy
+         * state changes
+         */
+        hpriv->flags &= ~AHCI_HFLAG_NO_HOTPLUG;
+
+        /*
+         * Enable interrupts on Phy Ready.
+         */
+        pp->intr_mask |= PORT_IRQ_PHYRDY;
+        writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+
+        /*
+         * don't change the link pm policy - we can be called
+         * just to turn of link pm temporarily
+         */
+}
+
+static int ahci_enable_alpm(struct ata_port *ap,
+        enum link_pm policy)
+{
+        struct ahci_host_priv *hpriv = ap->host->private_data;
+        void __iomem *port_mmio = ahci_port_base(ap);
+        u32 cmd;
+        struct ahci_port_priv *pp = ap->private_data;
+        u32 asp;
+
+        /* Make sure the host is capable of link power management */
+        if (!(hpriv->cap & HOST_CAP_ALPM))
+                return -EINVAL;
+
+        switch (policy) {
+        case MAX_PERFORMANCE:
+        case NOT_AVAILABLE:
+                /*
+                 * if we came here with NOT_AVAILABLE,
+                 * it just means this is the first time we
+                 * have tried to enable - default to max performance,
+                 * and let the user go to lower power modes on request.
+                 */
+                ahci_disable_alpm(ap);
+                return 0;
+        case MIN_POWER:
+                /* configure HBA to enter SLUMBER */
+                asp = PORT_CMD_ASP;
+                break;
+        case MEDIUM_POWER:
+                /* configure HBA to enter PARTIAL */
+                asp = 0;
+                break;
+        default:
+                return -EINVAL;
+        }
+
+        /*
+         * Disable interrupts on Phy Ready. This keeps us from
+         * getting woken up due to spurious phy ready interrupts
+         * TBD - Hot plug should be done via polling now, is
+         * that even supported?
+         */
+        pp->intr_mask &= ~PORT_IRQ_PHYRDY;
+        writel(pp->intr_mask, port_mmio + PORT_IRQ_MASK);
+
+        /*
+         * Set a flag to indicate that we should ignore all PhyRdy
+         * state changes since these can happen now whenever we
+         * change link state
+         */
+        hpriv->flags |= AHCI_HFLAG_NO_HOTPLUG;
+
+        /* get the existing command bits */
+        cmd = readl(port_mmio + PORT_CMD);
+
+        /*
+         * Set ASP based on Policy
+         */
+        cmd |= asp;
+
+        /*
+         * Setting this bit will instruct the HBA to aggressively
+         * enter a lower power link state when it's appropriate and
+         * based on the value set above for ASP
+         */
+        cmd |= PORT_CMD_ALPE;
+
+        /* write out new cmd value */
+        writel(cmd, port_mmio + PORT_CMD);
+        cmd = readl(port_mmio + PORT_CMD);
+
+        /* IPM bits should be set by libata-core */
+        return 0;
+}
+
 #ifdef CONFIG_PM
 static void ahci_power_down(struct ata_port *ap)
 {
@@ -1504,6 +1643,17 @@ static void ahci_port_intr(struct ata_port *ap)
         if (unlikely(resetting))
                 status &= ~PORT_IRQ_BAD_PMP;
 
+        /* If we are getting PhyRdy, this is
+         * just a power state change, we should
+         * clear out this, plus the PhyRdy/Comm
+         * Wake bits from Serror
+         */
+        if ((hpriv->flags & AHCI_HFLAG_NO_HOTPLUG) &&
+                (status & PORT_IRQ_PHYRDY)) {
+                status &= ~PORT_IRQ_PHYRDY;
+                ahci_scr_write(ap, SCR_ERROR, ((1 << 16) | (1 << 18)));
+        }
+
         if (unlikely(status & PORT_IRQ_ERROR)) {
                 ahci_error_intr(ap, status);
                 return;
@@ -2151,6 +2301,9 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
                 ata_port_pbar_desc(ap, AHCI_PCI_BAR,
                                    0x100 + ap->port_no * 0x80, "port");
 
+                /* set initial link pm policy */
+                ap->pm_policy = NOT_AVAILABLE;
+
                 /* standard SATA port setup */
                 if (hpriv->port_map & (1 << i))
                         ap->ioaddr.cmd_addr = port_mmio;