libata-pmp-prep: implement sata_async_notification()

AN serves multiple purposes.  For ATAPI, it's used for media change
notification.  For PMP, for downstream PHY status change notification.
Implement sata_async_notification() which demultiplexes AN.

To avoid unnecessary port events, ATAPI AN is not enabled if PMP is
attached but SNTF is not available.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Kriten Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index cf3404467cebecafb55724d07470b5019956d703..9f3c591c7214090f2cc4b5f17b921dd7de48f6c4 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1356,27 +1356,17 @@ static void ahci_port_intr(struct ata_port *ap)
        }
 
        if (status & PORT_IRQ_SDB_FIS) {
-               /*
-                * if this is an ATAPI device with AN turned on,
-                * then we should interrogate the device to
-                * determine the cause of the interrupt
-                *
-                * for AN - this we should check the SDB FIS
-                * and find the I and N bits set
+               /* If the 'N' bit in word 0 of the FIS is set, we just
+                * received asynchronous notification.  Tell libata
+                * about it.  Note that as the SDB FIS itself is
+                * accessible, SNotification can be emulated by the
+                * driver but don't bother for the time being.
                 */
                const __le32 *f = pp->rx_fis + RX_FIS_SDB;
                u32 f0 = le32_to_cpu(f[0]);
 
-               /* check the 'N' bit in word 0 of the FIS */
-               if (f0 & (1 << 15)) {
-                       int port_addr = ((f0 & 0x00000f00) >> 8);
-                       struct ata_device *adev;
-                       if (port_addr < ATA_MAX_DEVICES) {
-                               adev = &ap->link.device[port_addr];
-                               if (adev->flags & ATA_DFLAG_AN)
-                                       ata_scsi_media_change_notify(adev);
-                       }
-               }
+               if (f0 & (1 << 15))
+                       sata_async_notification(ap);
        }
 
        if (ap->link.sactive)

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 376dbd80cc93ae2611fe6fc378ce20f42a922462..8b08e7bdd24d59727bf3d7e3a94266a27e22e0d5 100644 (file)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -2016,6 +2016,7 @@ int ata_dev_configure(struct ata_device *dev)
        else if (dev->class == ATA_DEV_ATAPI) {
                const char *cdb_intr_string = "";
                const char *atapi_an_string = "";
+               u32 sntf;
 
                rc = atapi_cdb_len(id);
                if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
@@ -2027,11 +2028,14 @@ int ata_dev_configure(struct ata_device *dev)
                }
                dev->cdb_len = (unsigned int) rc;
 
-               /*
-                * check to see if this ATAPI device supports
-                * Asynchronous Notification
+               /* Enable ATAPI AN if both the host and device have
+                * the support.  If PMP is attached, SNTF is required
+                * to enable ATAPI AN to discern between PHY status
+                * changed notifications and ATAPI ANs.
                 */
-               if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id)) {
+               if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) &&
+                   (!ap->nr_pmp_links ||
+                    sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf) == 0)) {
                        unsigned int err_mask;
 
                        /* issue SET feature command to turn this on */
@@ -7248,6 +7252,7 @@ EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
 EXPORT_SYMBOL_GPL(ata_link_abort);
 EXPORT_SYMBOL_GPL(ata_port_abort);
 EXPORT_SYMBOL_GPL(ata_port_freeze);
+EXPORT_SYMBOL_GPL(sata_async_notification);
 EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
 EXPORT_SYMBOL_GPL(ata_eh_thaw_port);
 EXPORT_SYMBOL_GPL(ata_eh_qc_complete);

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 3c31e10caf21e16bee5ee942fe5a1b5725c8bc38..60186f8ac3a133ca6f3bdd38f317538295247b5b 100644 (file)
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -904,6 +904,79 @@ int ata_port_freeze(struct ata_port *ap)
        return nr_aborted;
 }
 
+/**
+ *     sata_async_notification - SATA async notification handler
+ *     @ap: ATA port where async notification is received
+ *
+ *     Handler to be called when async notification via SDB FIS is
+ *     received.  This function schedules EH if necessary.
+ *
+ *     LOCKING:
+ *     spin_lock_irqsave(host lock)
+ *
+ *     RETURNS:
+ *     1 if EH is scheduled, 0 otherwise.
+ */
+int sata_async_notification(struct ata_port *ap)
+{
+       u32 sntf;
+       int rc;
+
+       if (!(ap->flags & ATA_FLAG_AN))
+               return 0;
+
+       rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
+       if (rc == 0)
+               sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
+
+       if (!ap->nr_pmp_links || rc) {
+               /* PMP is not attached or SNTF is not available */
+               if (!ap->nr_pmp_links) {
+                       /* PMP is not attached.  Check whether ATAPI
+                        * AN is configured.  If so, notify media
+                        * change.
+                        */
+                       struct ata_device *dev = ap->link.device;
+
+                       if ((dev->class == ATA_DEV_ATAPI) &&
+                           (dev->flags & ATA_DFLAG_AN))
+                               ata_scsi_media_change_notify(dev);
+                       return 0;
+               } else {
+                       /* PMP is attached but SNTF is not available.
+                        * ATAPI async media change notification is
+                        * not used.  The PMP must be reporting PHY
+                        * status change, schedule EH.
+                        */
+                       ata_port_schedule_eh(ap);
+                       return 1;
+               }
+       } else {
+               /* PMP is attached and SNTF is available */
+               struct ata_link *link;
+
+               /* check and notify ATAPI AN */
+               ata_port_for_each_link(link, ap) {
+                       if (!(sntf & (1 << link->pmp)))
+                               continue;
+
+                       if ((link->device->class == ATA_DEV_ATAPI) &&
+                           (link->device->flags & ATA_DFLAG_AN))
+                               ata_scsi_media_change_notify(link->device);
+               }
+
+               /* If PMP is reporting that PHY status of some
+                * downstream ports has changed, schedule EH.
+                */
+               if (sntf & (1 << SATA_PMP_CTRL_PORT)) {
+                       ata_port_schedule_eh(ap);
+                       return 1;
+               }
+
+               return 0;
+       }
+}
+
 /**
  *     ata_eh_freeze_port - EH helper to freeze port
  *     @ap: ATA port to freeze

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 451f79c6fbace42bf8f015b309cbe1728b2036a2..df2e05738f3b3806238e10d5cc78bdb222270217 100644 (file)
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -3244,7 +3244,6 @@ void ata_scsi_media_change_notify(struct ata_device *dev)
                scsi_device_event_notify(dev->sdev, SDEV_MEDIA_CHANGE);
 #endif
 }
-EXPORT_SYMBOL_GPL(ata_scsi_media_change_notify);
 
 /**
  *     ata_scsi_hotplug - SCSI part of hotplug

diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 0f3e355fdfd7c761db441577cdb45e2aa02857ec..ebe22982e80ccf54b383d24523a4d7a4fb7bf1e9 100644 (file)
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -119,6 +119,7 @@ extern int ata_scsi_add_hosts(struct ata_host *host,
                              struct scsi_host_template *sht);
 extern void ata_scsi_scan_host(struct ata_port *ap, int sync);
 extern int ata_scsi_offline_dev(struct ata_device *dev);
+extern void ata_scsi_media_change_notify(struct ata_device *dev);
 extern void ata_scsi_hotplug(struct work_struct *work);
 extern unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf,
                               unsigned int buflen);

diff --git a/drivers/ata/sata_sil24.c b/drivers/ata/sata_sil24.c
index 9acfce43bde49aa43faaca4af394d709d1b3ea18..b4f81eb8bbbe586fb2f8d65cb462b875e400c9f6 100644 (file)
--- a/drivers/ata/sata_sil24.c
+++ b/drivers/ata/sata_sil24.c
@@ -821,11 +821,8 @@ static void sil24_error_intr(struct ata_port *ap)
        ata_ehi_push_desc(ehi, "irq_stat 0x%08x", irq_stat);
 
        if (irq_stat & PORT_IRQ_SDB_NOTIFY) {
-               struct ata_device *dev = ap->link.device;
-
                ata_ehi_push_desc(ehi, "SDB notify");
-               if (dev->flags & ATA_DFLAG_AN)
-                       ata_scsi_media_change_notify(dev);
+               sata_async_notification(ap);
        }
 
        if (irq_stat & (PORT_IRQ_PHYRDY_CHG | PORT_IRQ_DEV_XCHG)) {

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 56b218771114ab7ea562bbb581641e8bc0f92468..cd9c2a28136a407dfe77ecce0967141954c96151 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -139,7 +139,7 @@ enum {
        ATA_DFLAG_FLUSH_EXT     = (1 << 4), /* do FLUSH_EXT instead of FLUSH */
        ATA_DFLAG_ACPI_PENDING  = (1 << 5), /* ACPI resume action pending */
        ATA_DFLAG_ACPI_FAILED   = (1 << 6), /* ACPI on devcfg has failed */
-       ATA_DFLAG_AN            = (1 << 7), /* device supports AN */
+       ATA_DFLAG_AN            = (1 << 7), /* AN configured */
        ATA_DFLAG_CFG_MASK      = (1 << 12) - 1,
 
        ATA_DFLAG_PIO           = (1 << 12), /* device limited to PIO mode */
@@ -787,7 +787,6 @@ extern void ata_host_init(struct ata_host *, struct device *,
 extern int ata_scsi_detect(struct scsi_host_template *sht);
 extern int ata_scsi_ioctl(struct scsi_device *dev, int cmd, void __user *arg);
 extern int ata_scsi_queuecmd(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *));
-extern void ata_scsi_media_change_notify(struct ata_device *atadev);
 extern void ata_sas_port_destroy(struct ata_port *);
 extern struct ata_port *ata_sas_port_alloc(struct ata_host *,
                                           struct ata_port_info *, struct Scsi_Host *);
@@ -953,6 +952,7 @@ extern void ata_port_schedule_eh(struct ata_port *ap);
 extern int ata_link_abort(struct ata_link *link);
 extern int ata_port_abort(struct ata_port *ap);
 extern int ata_port_freeze(struct ata_port *ap);
+extern int sata_async_notification(struct ata_port *ap);
 
 extern void ata_eh_freeze_port(struct ata_port *ap);
 extern void ata_eh_thaw_port(struct ata_port *ap);