sata_mv: introduce support for ATAPI devices

Add ATAPI support to sata_mv, using sff DMA for GEN_II chipsets,
and plain old PIO for GEN_IIE.

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

1 files changed, 186 insertions, 4 deletions

diff --git a/drivers/ata/sata_mv.c b/drivers/ata/sata_mv.c
index 9c8ea2c1116d..6f8a49bc4521 100644
--- a/drivers/ata/sata_mv.c
+++ b/drivers/ata/sata_mv.c
@@ -31,8 +31,6 @@
  *
  * --> Complete a full errata audit for all chipsets to identify others.
  *
- * --> ATAPI support (Marvell claims the 60xx/70xx chips can do it).
- *
  * --> Develop a low-power-consumption strategy, and implement it.
  *
  * --> [Experiment, low priority] Investigate interrupt coalescing.
@@ -68,7 +66,7 @@
 #include <linux/libata.h>
 
 #define DRV_NAME        "sata_mv"
-#define DRV_VERSION     "1.25"
+#define DRV_VERSION     "1.26"
 
 enum {
         /* BAR's are enumerated in terms of pci_resource_start() terms */
@@ -126,7 +124,7 @@ enum {
 
         MV_GEN_II_FLAGS         = MV_COMMON_FLAGS | MV_FLAG_IRQ_COALESCE |
                                   ATA_FLAG_PMP | ATA_FLAG_ACPI_SATA |
-                                  ATA_FLAG_NCQ | ATA_FLAG_NO_ATAPI,
+                                  ATA_FLAG_NCQ,
 
         MV_GEN_IIE_FLAGS        = MV_GEN_II_FLAGS | ATA_FLAG_AN,
 
@@ -348,6 +346,12 @@ enum {
 
         EDMA_HALTCOND_OFS       = 0x60,         /* GenIIe halt conditions */
 
+
+        BMDMA_CMD_OFS           = 0x224,        /* bmdma command register */
+        BMDMA_STATUS_OFS        = 0x228,        /* bmdma status register */
+        BMDMA_PRD_LOW_OFS       = 0x22c,        /* bmdma PRD addr 31:0 */
+        BMDMA_PRD_HIGH_OFS      = 0x230,        /* bmdma PRD addr 63:32 */
+
         /* Host private flags (hp_flags) */
         MV_HP_FLAG_MSI          = (1 << 0),
         MV_HP_ERRATA_50XXB0     = (1 << 1),
@@ -547,6 +551,15 @@ static void mv_pmp_error_handler(struct ata_port *ap);
 static void mv_process_crpb_entries(struct ata_port *ap,
                                         struct mv_port_priv *pp);
 
+static unsigned long mv_mode_filter(struct ata_device *dev,
+                                    unsigned long xfer_mask);
+static void mv_sff_irq_clear(struct ata_port *ap);
+static int mv_check_atapi_dma(struct ata_queued_cmd *qc);
+static void mv_bmdma_setup(struct ata_queued_cmd *qc);
+static void mv_bmdma_start(struct ata_queued_cmd *qc);
+static void mv_bmdma_stop(struct ata_queued_cmd *qc);
+static u8   mv_bmdma_status(struct ata_port *ap);
+
 /* .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().
@@ -594,6 +607,14 @@ static struct ata_port_operations mv6_ops = {
         .pmp_softreset          = mv_softreset,
         .softreset              = mv_softreset,
         .error_handler          = mv_pmp_error_handler,
+
+        .sff_irq_clear          = mv_sff_irq_clear,
+        .check_atapi_dma        = mv_check_atapi_dma,
+        .bmdma_setup            = mv_bmdma_setup,
+        .bmdma_start            = mv_bmdma_start,
+        .bmdma_stop             = mv_bmdma_stop,
+        .bmdma_status           = mv_bmdma_status,
+        .mode_filter            = mv_mode_filter,
 };
 
 static struct ata_port_operations mv_iie_ops = {
@@ -1393,6 +1414,167 @@ static void mv_crqb_pack_cmd(__le16 *cmdw, u8 data, u8 addr, unsigned last)
 }
 
 /**
+ *      mv_mode_filter - Allow ATAPI DMA only on GenII chips.
+ *      @dev: device whose xfer modes are being configured.
+ *
+ *      Only the GenII hardware can use DMA with ATAPI drives.
+ */
+static unsigned long mv_mode_filter(struct ata_device *adev,
+                                    unsigned long xfer_mask)
+{
+        if (adev->class == ATA_DEV_ATAPI) {
+                struct mv_host_priv *hpriv = adev->link->ap->host->private_data;
+                if (!IS_GEN_II(hpriv)) {
+                        xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
+                        ata_dev_printk(adev, KERN_INFO,
+                                "ATAPI DMA not supported on this chipset\n");
+                }
+        }
+        return xfer_mask;
+}
+
+/**
+ *      mv_sff_irq_clear - Clear hardware interrupt after DMA.
+ *      @ap: Port associated with this ATA transaction.
+ *
+ *      We need this only for ATAPI bmdma transactions,
+ *      as otherwise we experience spurious interrupts
+ *      after libata-sff handles the bmdma interrupts.
+ */
+static void mv_sff_irq_clear(struct ata_port *ap)
+{
+        mv_clear_and_enable_port_irqs(ap, mv_ap_base(ap), ERR_IRQ);
+}
+
+/**
+ *      mv_check_atapi_dma - Filter ATAPI cmds which are unsuitable for DMA.
+ *      @qc: queued command to check for chipset/DMA compatibility.
+ *
+ *      The bmdma engines cannot handle speculative data sizes
+ *      (bytecount under/over flow).  So only allow DMA for
+ *      data transfer commands with known data sizes.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ */
+static int mv_check_atapi_dma(struct ata_queued_cmd *qc)
+{
+        struct scsi_cmnd *scmd = qc->scsicmd;
+
+        if (scmd) {
+                switch (scmd->cmnd[0]) {
+                case READ_6:
+                case READ_10:
+                case READ_12:
+                case WRITE_6:
+                case WRITE_10:
+                case WRITE_12:
+                case GPCMD_READ_CD:
+                case GPCMD_SEND_DVD_STRUCTURE:
+                case GPCMD_SEND_CUE_SHEET:
+                        return 0; /* DMA is safe */
+                }
+        }
+        return -EOPNOTSUPP; /* use PIO instead */
+}
+
+/**
+ *      mv_bmdma_setup - Set up BMDMA transaction
+ *      @qc: queued command to prepare DMA for.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ */
+static void mv_bmdma_setup(struct ata_queued_cmd *qc)
+{
+        struct ata_port *ap = qc->ap;
+        void __iomem *port_mmio = mv_ap_base(ap);
+        struct mv_port_priv *pp = ap->private_data;
+
+        mv_fill_sg(qc);
+
+        /* clear all DMA cmd bits */
+        writel(0, port_mmio + BMDMA_CMD_OFS);
+
+        /* load PRD table addr. */
+        writel((pp->sg_tbl_dma[qc->tag] >> 16) >> 16,
+                port_mmio + BMDMA_PRD_HIGH_OFS);
+        writelfl(pp->sg_tbl_dma[qc->tag],
+                port_mmio + BMDMA_PRD_LOW_OFS);
+
+        /* issue r/w command */
+        ap->ops->sff_exec_command(ap, &qc->tf);
+}
+
+/**
+ *      mv_bmdma_start - Start a BMDMA transaction
+ *      @qc: queued command to start DMA on.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ */
+static void mv_bmdma_start(struct ata_queued_cmd *qc)
+{
+        struct ata_port *ap = qc->ap;
+        void __iomem *port_mmio = mv_ap_base(ap);
+        unsigned int rw = (qc->tf.flags & ATA_TFLAG_WRITE);
+        u32 cmd = (rw ? 0 : ATA_DMA_WR) | ATA_DMA_START;
+
+        /* start host DMA transaction */
+        writelfl(cmd, port_mmio + BMDMA_CMD_OFS);
+}
+
+/**
+ *      mv_bmdma_stop - Stop BMDMA transfer
+ *      @qc: queued command to stop DMA on.
+ *
+ *      Clears the ATA_DMA_START flag in the bmdma control register
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ */
+static void mv_bmdma_stop(struct ata_queued_cmd *qc)
+{
+        struct ata_port *ap = qc->ap;
+        void __iomem *port_mmio = mv_ap_base(ap);
+        u32 cmd;
+
+        /* clear start/stop bit */
+        cmd = readl(port_mmio + BMDMA_CMD_OFS);
+        cmd &= ~ATA_DMA_START;
+        writelfl(cmd, port_mmio + BMDMA_CMD_OFS);
+
+        /* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
+        ata_sff_dma_pause(ap);
+}
+
+/**
+ *      mv_bmdma_status - Read BMDMA status
+ *      @ap: port for which to retrieve DMA status.
+ *
+ *      Read and return equivalent of the sff BMDMA status register.
+ *
+ *      LOCKING:
+ *      Inherited from caller.
+ */
+static u8 mv_bmdma_status(struct ata_port *ap)
+{
+        void __iomem *port_mmio = mv_ap_base(ap);
+        u32 reg, status;
+
+        /*
+         * Other bits are valid only if ATA_DMA_ACTIVE==0,
+         * and the ATA_DMA_INTR bit doesn't exist.
+         */
+        reg = readl(port_mmio + BMDMA_STATUS_OFS);
+        if (reg & ATA_DMA_ACTIVE)
+                status = ATA_DMA_ACTIVE;
+        else
+                status = (reg & ATA_DMA_ERR) | ATA_DMA_INTR;
+        return status;
+}
+
+/**
  *      mv_qc_prep - Host specific command preparation.
  *      @qc: queued command to prepare
  *