sata_mv add basic port multiplier support

Add basic port-multiplier support to sata_mv.
This works in Command-based-switching mode for Gen-II chipsets,
and in FIS-based-switching mode for Gen-IIe chipsets.

Error handling remains at the primary port level for now
(works okay, but not great).  This will get fixed in a subsequent
patch series for IRQ/EH handling fixes.  There are also some
known NCQ/PMP errata to be dealt with in the near future,
once we have this basic PMP support in place.

Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 89 insertions, 4 deletions

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index 6a7420546609..b822b8a40c65 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -40,7 +40,7 @@
 
   5) Investigate problems with PCI Message Signalled Interrupts (MSI).
 
-  6) Add port multiplier support (intermediate)
+  6) Cache frequently-accessed registers in mv_port_priv to reduce overhead.
 
   7) Fix/reenable hot plug/unplug (should happen as a side-effect of (2) above).
 
@@ -528,6 +528,12 @@ static int mv_stop_edma(struct ata_port *ap);
 static int mv_stop_edma_engine(void __iomem *port_mmio);
 static void mv_edma_cfg(struct ata_port *ap, int want_ncq);
 
+static void mv_pmp_select(struct ata_port *ap, int pmp);
+static int mv_pmp_hardreset(struct ata_link *link, unsigned int *class,
+                                unsigned long deadline);
+static int  mv_softreset(struct ata_link *link, unsigned int *class,
+                                unsigned long deadline);
+
 /* .sg_tablesize is (MV_MAX_SG_CT / 2) in the structures below
  * because we have to allow room for worst case splitting of
  * PRDs for 64K boundaries in mv_fill_sg().
@@ -566,14 +572,20 @@ static struct ata_port_operations mv5_ops = {
 
 static struct ata_port_operations mv6_ops = {
         .inherits               = &mv5_ops,
-        .qc_defer               = ata_std_qc_defer,
+        .qc_defer               = sata_pmp_qc_defer_cmd_switch,
         .dev_config             = mv6_dev_config,
         .scr_read               = mv_scr_read,
         .scr_write              = mv_scr_write,
+
+        .pmp_hardreset          = mv_pmp_hardreset,
+        .pmp_softreset          = mv_softreset,
+        .softreset              = mv_softreset,
+        .error_handler          = sata_pmp_error_handler,
 };
 
 static struct ata_port_operations mv_iie_ops = {
         .inherits               = &mv6_ops,
+        .qc_defer               = ata_std_qc_defer, /* FIS-based switching */
         .dev_config             = ATA_OP_NULL,
         .qc_prep                = mv_qc_prep_iie,
 };
@@ -599,6 +611,7 @@ static const struct ata_port_info mv_port_info[] = {
         },
         {  /* chip_604x */
                 .flags          = MV_COMMON_FLAGS | MV_6XXX_FLAGS |
+                                  ATA_FLAG_PMP | ATA_FLAG_ACPI_SATA |
                                   ATA_FLAG_NCQ,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .udma_mask      = ATA_UDMA6,
@@ -606,6 +619,7 @@ static const struct ata_port_info mv_port_info[] = {
         },
         {  /* chip_608x */
                 .flags          = MV_COMMON_FLAGS | MV_6XXX_FLAGS |
+                                  ATA_FLAG_PMP | ATA_FLAG_ACPI_SATA |
                                   ATA_FLAG_NCQ | MV_FLAG_DUAL_HC,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .udma_mask      = ATA_UDMA6,
@@ -613,6 +627,7 @@ static const struct ata_port_info mv_port_info[] = {
         },
         {  /* chip_6042 */
                 .flags          = MV_COMMON_FLAGS | MV_6XXX_FLAGS |
+                                  ATA_FLAG_PMP | ATA_FLAG_ACPI_SATA |
                                   ATA_FLAG_NCQ,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .udma_mask      = ATA_UDMA6,
@@ -620,6 +635,7 @@ static const struct ata_port_info mv_port_info[] = {
         },
         {  /* chip_7042 */
                 .flags          = MV_COMMON_FLAGS | MV_6XXX_FLAGS |
+                                  ATA_FLAG_PMP | ATA_FLAG_ACPI_SATA |
                                   ATA_FLAG_NCQ,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .udma_mask      = ATA_UDMA6,
@@ -627,6 +643,7 @@ static const struct ata_port_info mv_port_info[] = {
         },
         {  /* chip_soc */
                 .flags          = MV_COMMON_FLAGS | MV_6XXX_FLAGS |
+                                  ATA_FLAG_PMP | ATA_FLAG_ACPI_SATA |
                                   ATA_FLAG_NCQ | MV_FLAG_SOC,
                 .pio_mask       = 0x1f, /* pio0-4 */
                 .udma_mask      = ATA_UDMA6,
@@ -1006,12 +1023,42 @@ static int mv_scr_write(struct ata_port *ap, unsigned int sc_reg_in, u32 val)
 static void mv6_dev_config(struct ata_device *adev)
 {
         /*
+         * Deal with Gen-II ("mv6") hardware quirks/restrictions:
+         *
+         * Gen-II does not support NCQ over a port multiplier
+         *  (no FIS-based switching).
+         *
          * We don't have hob_nsect when doing NCQ commands on Gen-II.
          * See mv_qc_prep() for more info.
          */
-        if (adev->flags & ATA_DFLAG_NCQ)
-                if (adev->max_sectors > ATA_MAX_SECTORS)
+        if (adev->flags & ATA_DFLAG_NCQ) {
+                if (sata_pmp_attached(adev->link->ap))
+                        adev->flags &= ~ATA_DFLAG_NCQ;
+                else if (adev->max_sectors > ATA_MAX_SECTORS)
                         adev->max_sectors = ATA_MAX_SECTORS;
+        }
+}
+
+static void mv_config_fbs(void __iomem *port_mmio, int enable_fbs)
+{
+        u32 old_fcfg, new_fcfg, old_ltmode, new_ltmode;
+        /*
+         * Various bit settings required for operation
+         * in FIS-based switching (fbs) mode on GenIIe:
+         */
+        old_fcfg   = readl(port_mmio + FIS_CFG_OFS);
+        old_ltmode = readl(port_mmio + LTMODE_OFS);
+        if (enable_fbs) {
+                new_fcfg   = old_fcfg   |  FIS_CFG_SINGLE_SYNC;
+                new_ltmode = old_ltmode |  LTMODE_BIT8;
+        } else { /* disable fbs */
+                new_fcfg   = old_fcfg   & ~FIS_CFG_SINGLE_SYNC;
+                new_ltmode = old_ltmode & ~LTMODE_BIT8;
+        }
+        if (new_fcfg != old_fcfg)
+                writelfl(new_fcfg, port_mmio + FIS_CFG_OFS);
+        if (new_ltmode != old_ltmode)
+                writelfl(new_ltmode, port_mmio + LTMODE_OFS);
 }
 
 static void mv_edma_cfg(struct ata_port *ap, int want_ncq)
@@ -1035,6 +1082,13 @@ static void mv_edma_cfg(struct ata_port *ap, int want_ncq)
                 cfg |= (1 << 22);       /* enab 4-entry host queue cache */
                 cfg |= (1 << 18);       /* enab early completion */
                 cfg |= (1 << 17);       /* enab cut-through (dis stor&forwrd) */
+
+                if (want_ncq && sata_pmp_attached(ap)) {
+                        cfg |= EDMA_CFG_EDMA_FBS; /* FIS-based switching */
+                        mv_config_fbs(port_mmio, 1);
+                } else {
+                        mv_config_fbs(port_mmio, 0);
+                }
         }
 
         if (want_ncq) {
@@ -1240,6 +1294,7 @@ static void mv_qc_prep(struct ata_queued_cmd *qc)
                 flags |= CRQB_FLAG_READ;
         WARN_ON(MV_MAX_Q_DEPTH <= qc->tag);
         flags |= qc->tag << CRQB_TAG_SHIFT;
+        flags |= (qc->dev->link->pmp & 0xf) << CRQB_PMP_SHIFT;
 
         /* get current queue index from software */
         in_index = pp->req_idx & MV_MAX_Q_DEPTH_MASK;
@@ -1331,6 +1386,7 @@ static void mv_qc_prep_iie(struct ata_queued_cmd *qc)
         WARN_ON(MV_MAX_Q_DEPTH <= qc->tag);
         flags |= qc->tag << CRQB_TAG_SHIFT;
         flags |= qc->tag << CRQB_HOSTQ_SHIFT;
+        flags |= (qc->dev->link->pmp & 0xf) << CRQB_PMP_SHIFT;
 
         /* get current queue index from software */
         in_index = pp->req_idx & MV_MAX_Q_DEPTH_MASK;
@@ -1394,6 +1450,7 @@ static unsigned int mv_qc_issue(struct ata_queued_cmd *qc)
                  * shadow block, etc registers.
                  */
                 mv_stop_edma(ap);
+                mv_pmp_select(ap, qc->dev->link->pmp);
                 return ata_sff_qc_issue(qc);
         }
 
@@ -2289,6 +2346,34 @@ static void mv_reset_channel(struct mv_host_priv *hpriv, void __iomem *mmio,
                 mdelay(1);
 }
 
+static void mv_pmp_select(struct ata_port *ap, int pmp)
+{
+        if (sata_pmp_supported(ap)) {
+                void __iomem *port_mmio = mv_ap_base(ap);
+                u32 reg = readl(port_mmio + SATA_IFCTL_OFS);
+                int old = reg & 0xf;
+
+                if (old != pmp) {
+                        reg = (reg & ~0xf) | pmp;
+                        writelfl(reg, port_mmio + SATA_IFCTL_OFS);
+                }
+        }
+}
+
+static int mv_pmp_hardreset(struct ata_link *link, unsigned int *class,
+                                unsigned long deadline)
+{
+        mv_pmp_select(link->ap, sata_srst_pmp(link));
+        return sata_std_hardreset(link, class, deadline);
+}
+
+static int mv_softreset(struct ata_link *link, unsigned int *class,
+                                unsigned long deadline)
+{
+        mv_pmp_select(link->ap, sata_srst_pmp(link));
+        return ata_sff_softreset(link, class, deadline);
+}
+
 static int mv_hardreset(struct ata_link *link, unsigned int *class,
                         unsigned long deadline)
 {