sata_mv pci features

Some of the GenIIe EDMA optimizations should not be used
for non-PCI (SOC) devices, and nor for certain configurations
of conventional PCI (non PCI-X, PCIe) buses.

Logic taken/simplified from that in the Marvell proprietary driver.

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

1 files changed, 36 insertions, 3 deletions

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index 4eabb737a48d..10ef9683f048 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -361,6 +361,7 @@ enum {
         MV_HP_GEN_II            = (1 << 7),     /* Generation II: 60xx */
         MV_HP_GEN_IIE           = (1 << 8),     /* Generation IIE: 6042/7042 */
         MV_HP_PCIE              = (1 << 9),     /* PCIe bus/regs: 7042 */
+        MV_HP_CUT_THROUGH       = (1 << 10),    /* can use EDMA cut-through */
 
         /* Port private flags (pp_flags) */
         MV_PP_FLAG_EDMA_EN      = (1 << 0),     /* is EDMA engine enabled? */
@@ -1110,8 +1111,10 @@ static void mv_edma_cfg(struct ata_port *ap, int want_ncq)
         else if (IS_GEN_IIE(hpriv)) {
                 cfg |= (1 << 23);       /* do not mask PM field in rx'd FIS */
                 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 (HAS_PCI(ap->host))
+                        cfg |= (1 << 18);       /* enab early completion */
+                if (hpriv->hp_flags & MV_HP_CUT_THROUGH)
+                        cfg |= (1 << 17); /* enab cut-thru (dis stor&forwrd) */
 
                 if (want_ncq && sata_pmp_attached(ap)) {
                         cfg |= EDMA_CFG_EDMA_FBS; /* FIS-based switching */
@@ -2496,6 +2499,34 @@ static void mv_port_init(struct ata_ioports *port,  void __iomem *port_mmio)
                 readl(port_mmio + EDMA_ERR_IRQ_MASK_OFS));
 }
 
+static unsigned int mv_in_pcix_mode(struct ata_host *host)
+{
+        struct mv_host_priv *hpriv = host->private_data;
+        void __iomem *mmio = hpriv->base;
+        u32 reg;
+
+        if (!HAS_PCI(host) || !IS_PCIE(hpriv))
+                return 0;       /* not PCI-X capable */
+        reg = readl(mmio + MV_PCI_MODE_OFS);
+        if ((reg & MV_PCI_MODE_MASK) == 0)
+                return 0;       /* conventional PCI mode */
+        return 1;       /* chip is in PCI-X mode */
+}
+
+static int mv_pci_cut_through_okay(struct ata_host *host)
+{
+        struct mv_host_priv *hpriv = host->private_data;
+        void __iomem *mmio = hpriv->base;
+        u32 reg;
+
+        if (!mv_in_pcix_mode(host)) {
+                reg = readl(mmio + PCI_COMMAND_OFS);
+                if (reg & PCI_COMMAND_MRDTRIG)
+                        return 0; /* not okay */
+        }
+        return 1; /* okay */
+}
+
 static int mv_chip_id(struct ata_host *host, unsigned int board_idx)
 {
         struct pci_dev *pdev = to_pci_dev(host->dev);
@@ -2563,7 +2594,7 @@ static int mv_chip_id(struct ata_host *host, unsigned int board_idx)
                 break;
 
         case chip_7042:
-                hp_flags |= MV_HP_PCIE;
+                hp_flags |= MV_HP_PCIE | MV_HP_CUT_THROUGH;
                 if (pdev->vendor == PCI_VENDOR_ID_TTI &&
                     (pdev->device == 0x2300 || pdev->device == 0x2310))
                 {
@@ -2597,6 +2628,8 @@ static int mv_chip_id(struct ata_host *host, unsigned int board_idx)
         case chip_6042:
                 hpriv->ops = &mv6xxx_ops;
                 hp_flags |= MV_HP_GEN_IIE;
+                if (board_idx == chip_6042 && mv_pci_cut_through_okay(host))
+                        hp_flags |= MV_HP_CUT_THROUGH;
 
                 switch (pdev->revision) {
                 case 0x0: