[libata] fill in a lot more Promise PDC20621 support

drivers/scsi/sata_promise.c

@@ -41,6 +41,7 @@ enum {
 	PDC_PRD_TBL		= 0x44,	/* Direct command DMA table addr */
 
 	PDC_PKT_SUBMIT		= 0x40, /* Command packet pointer addr */
+	PDC_HDMA_PKT_SUBMIT	= 0x100, /* Host DMA packet pointer addr */
 	PDC_INT_SEQMASK		= 0x40,	/* Mask of asserted SEQ INTs */
 	PDC_TBG_MODE		= 0x41,	/* TBG mode */
 	PDC_FLASH_CTL		= 0x44, /* Flash control register */
@@ -50,6 +51,12 @@ enum {
 	PDC_20621_SEQCTL	= 0x400,
 	PDC_20621_SEQMASK	= 0x480,
 
+	/* chosen, not constant, values; we design our own DIMM mem map */
+	PDC_20621_DIMM_WINDOW	= 0x0C,	/* page# for 32K DIMM window */
+	PDC_20621_DIMM_BASE	= 0x00200000,
+	PDC_20621_HOST_PRD	= 64,
+	PDC_20621_ATA_PRD	= 72,
+
 	PDC_CHIP0_OFS		= 0xC0000, /* offset of chip #0 */
 
 	board_2037x		= 0,	/* FastTrak S150 TX2plus */
@@ -61,6 +68,8 @@ enum {
 
 
 struct pdc_port_priv {
+	u8			prd_buf[ATA_PRD_SZ * ATA_MAX_PRD];
+	u8			pkt_buf[256];
 	u8			*pkt;
 	dma_addr_t		pkt_dma;
 };
@@ -74,14 +83,20 @@ static void pdc_sata_set_udmamode (struct ata_port *ap, struct ata_device *adev,
 			      unsigned int udma);
 static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *ent);
 static void pdc_dma_start(struct ata_queued_cmd *qc);
+static void pdc20621_dma_start(struct ata_queued_cmd *qc);
 static irqreturn_t pdc_interrupt (int irq, void *dev_instance, struct pt_regs *regs);
+static irqreturn_t pdc20621_interrupt (int irq, void *dev_instance, struct pt_regs *regs);
 static void pdc_eng_timeout(struct ata_port *ap);
 static void pdc_20621_phy_reset (struct ata_port *ap);
 static int pdc_port_start(struct ata_port *ap);
 static void pdc_port_stop(struct ata_port *ap);
 static void pdc_fill_sg(struct ata_queued_cmd *qc);
+static void pdc20621_fill_sg(struct ata_queued_cmd *qc);
 static void pdc_tf_load_mmio(struct ata_port *ap, struct ata_taskfile *tf);
 static void pdc_exec_command_mmio(struct ata_port *ap, struct ata_taskfile *tf);
+static void pdc20621_host_stop(struct ata_host_set *host_set);
+static inline void pdc_dma_complete (struct ata_port *ap,
+                                     struct ata_queued_cmd *qc);
 
 
 static Scsi_Host_Template pdc_sata_sht = {
@@ -131,12 +146,13 @@ static struct ata_port_operations pdc_20621_ops = {
 	.exec_command		= pdc_exec_command_mmio,
 	.phy_reset		= pdc_20621_phy_reset,
 	.phy_config		= pata_phy_config,	/* not a typo */
-	.bmdma_start            = pdc_dma_start,
-	.fill_sg		= pdc_fill_sg,
+	.bmdma_start            = pdc20621_dma_start,
+	.fill_sg		= pdc20621_fill_sg,
 	.eng_timeout		= pdc_eng_timeout,
-	.irq_handler		= pdc_interrupt,
+	.irq_handler		= pdc20621_interrupt,
 	.port_start		= pdc_port_start,
 	.port_stop		= pdc_port_stop,
+	.host_stop		= pdc20621_host_stop,
 };
 
 static struct ata_port_info pdc_port_info[] = {
@@ -182,10 +198,8 @@ static struct pci_device_id pdc_sata_pci_tbl[] = {
 	  board_20319 },
 	{ PCI_VENDOR_ID_PROMISE, 0x3319, PCI_ANY_ID, PCI_ANY_ID, 0, 0,
 	  board_20319 },
-#if 0 /* broken currently */
 	{ PCI_VENDOR_ID_PROMISE, 0x6622, PCI_ANY_ID, PCI_ANY_ID, 0, 0,
 	  board_20621 },
-#endif
 	{ }	/* terminate list */
 };
 
@@ -198,6 +212,14 @@ static struct pci_driver pdc_sata_pci_driver = {
 };
 
 
+static void pdc20621_host_stop(struct ata_host_set *host_set)
+{
+	void *mmio = host_set->private_data;
+
+	assert(mmio != NULL);
+	iounmap(mmio);
+}
+
 static int pdc_port_start(struct ata_port *ap)
 {
 	struct pci_dev *pdev = ap->host_set->pdev;
@@ -284,6 +306,7 @@ static void pdc_sata_set_udmamode (struct ata_port *ap, struct ata_device *adev,
 enum pdc_packet_bits {
 	PDC_PKT_READ		= (1 << 2),
 	PDC_PKT_NODATA		= (1 << 3),
+	PDC20621_PKT_READ	= (1 << 4),
 
 	PDC_PKT_SIZEMASK	= (1 << 7) | (1 << 6) | (1 << 5),
 	PDC_PKT_CLEAR_BSY	= (1 << 4),
@@ -293,8 +316,9 @@ enum pdc_packet_bits {
 	PDC_REG_DEVCTL		= (1 << 3) | (1 << 2) | (1 << 1),
 };
 
-static inline void pdc_pkt_header(struct ata_taskfile *tf, dma_addr_t sg_table,
-				  unsigned int devno, u8 *buf)
+static inline unsigned int pdc_pkt_header(struct ata_taskfile *tf,
+					  dma_addr_t sg_table,
+					  unsigned int devno, u8 *buf)
 {
 	u8 dev_reg;
 	u32 *buf32 = (u32 *) buf;
@@ -335,9 +359,11 @@ static inline void pdc_pkt_header(struct ata_taskfile *tf, dma_addr_t sg_table,
 	/* device control register */
 	buf[14] = (1 << 5) | PDC_REG_DEVCTL;
 	buf[15] = tf->ctl;
+
+	return 16; 	/* offset of next byte */
 }
 
-static inline void pdc_pkt_footer(struct ata_taskfile *tf, u8 *buf,
+static inline unsigned int pdc_pkt_footer(struct ata_taskfile *tf, u8 *buf,
 				  unsigned int i)
 {
 	if (tf->flags & ATA_TFLAG_DEVICE) {
@@ -348,19 +374,14 @@ static inline void pdc_pkt_footer(struct ata_taskfile *tf, u8 *buf,
 	/* and finally the command itself; also includes end-of-pkt marker */
 	buf[i++] = (1 << 5) | PDC_LAST_REG | ATA_REG_CMD;
 	buf[i++] = tf->command;
+
+	return i;
 }
 
-static void pdc_prep_lba28(struct ata_taskfile *tf, dma_addr_t sg_table,
-			   unsigned int devno, u8 *buf)
+static inline unsigned int pdc_prep_lba28(struct ata_taskfile *tf, u8 *buf, unsigned int i)
 {
-	unsigned int i;
-
-	pdc_pkt_header(tf, sg_table, devno, buf);
-
 	/* the "(1 << 5)" should be read "(count << 5)" */
 
-	i = 16;
-
 	/* ATA command block registers */
 	buf[i++] = (1 << 5) | ATA_REG_FEATURE;
 	buf[i++] = tf->feature;
@@ -377,20 +398,13 @@ static void pdc_prep_lba28(struct ata_taskfile *tf, dma_addr_t sg_table,
 	buf[i++] = (1 << 5) | ATA_REG_LBAH;
 	buf[i++] = tf->lbah;
 
-	pdc_pkt_footer(tf, buf, i);
+	return i;
 }
 
-static void pdc_prep_lba48(struct ata_taskfile *tf, dma_addr_t sg_table,
-			   unsigned int devno, u8 *buf)
+static inline unsigned int pdc_prep_lba48(struct ata_taskfile *tf, u8 *buf, unsigned int i)
 {
-	unsigned int i;
-
-	pdc_pkt_header(tf, sg_table, devno, buf);
-
 	/* the "(2 << 5)" should be read "(count << 5)" */
 
-	i = 16;
-
 	/* ATA command block registers */
 	buf[i++] = (2 << 5) | ATA_REG_FEATURE;
 	buf[i++] = tf->hob_feature;
@@ -412,41 +426,299 @@ static void pdc_prep_lba48(struct ata_taskfile *tf, dma_addr_t sg_table,
 	buf[i++] = tf->hob_lbah;
 	buf[i++] = tf->lbah;
 
-	pdc_pkt_footer(tf, buf, i);
+	return i;
 }
 
-static void pdc_fill_sg(struct ata_queued_cmd *qc)
+static inline unsigned int pdc20621_pkt_header(struct ata_taskfile *tf,
+					  unsigned int portno,
+					  unsigned int devno,
+					  u8 *buf,
+					  unsigned int total_len)
 {
-	struct pdc_port_priv *pp = qc->ap->private_data;
+	u8 dev_reg;
+	u32 *buf32 = (u32 *) buf;
+	unsigned int ofs, i = 0;
+
+	/*
+	 * Set up Host DMA packet
+	 */
+	if (tf->protocol == ATA_PROT_DMA_READ)
+		buf[i++] = PDC20621_PKT_READ;
+	else
+		buf[i++] = 0;
+	buf[i++] = 0;			/* reserved */
+	buf[i++] = portno + 1 + 4;	/* seq. id */
+	buf[i++] = 0xff;			/* delay seq. id */
+	buf32[i / 4] = cpu_to_le32(PDC_20621_DIMM_BASE + (4 * 1024) +
+			       (2 * 1024 * portno));
+	i += 4;
+	buf32[i / 4] = cpu_to_le32(PDC_20621_DIMM_BASE + (portno * 1024) +
+			       PDC_20621_HOST_PRD);
+	i += 4;
+	buf32[i / 4] = 0;
+	i += 4;
+
+	ofs = PDC_20621_HOST_PRD / 4;
+	buf32[ofs] = cpu_to_le32(PDC_20621_DIMM_BASE + (32 * 1024) +
+		    (256 * 1024 * portno));
+	buf32[ofs + 1] = cpu_to_le32(total_len | ATA_PRD_EOT);
+
+	/*
+	 * Set up ATA packet
+	 */
+	if (tf->protocol == ATA_PROT_DMA_READ)
+		buf[i++] = PDC_PKT_READ;
+	else if (tf->protocol == ATA_PROT_NODATA)
+		buf[i++] = PDC_PKT_NODATA;
+	else
+		buf[i++] = 0;
+	buf[i++] = 0;			/* reserved */
+	buf[i++] = portno + 1;		/* seq. id */
+	buf[i++] = 0xff;		/* delay seq. id */
+	buf32[i / 4] = cpu_to_le32(PDC_20621_DIMM_BASE + (portno * 1024) +
+			       PDC_20621_ATA_PRD);
+	i += 4;
+	buf32[i / 4] = 0;			/* no next-packet */
+	i += 4;
+
+	ofs = PDC_20621_ATA_PRD / 4;
+	buf32[ofs] = cpu_to_le32(PDC_20621_DIMM_BASE + (32 * 1024) +
+		    (256 * 1024 * portno));
+	buf32[ofs + 1] = cpu_to_le32(total_len | ATA_PRD_EOT);
+
+	if (devno == 0)
+		dev_reg = ATA_DEVICE_OBS;
+	else
+		dev_reg = ATA_DEVICE_OBS | ATA_DEV1;
+
+	/* select device */
+	buf[i++] = (1 << 5) | PDC_PKT_CLEAR_BSY | ATA_REG_DEVICE;
+	buf[i++] = dev_reg;
+
+	/* device control register */
+	buf[i++] = (1 << 5) | PDC_REG_DEVCTL;
+	buf[i++] = tf->ctl;
+
+	return i; 	/* offset of next byte */
+}
+
+static void pdc20621_fill_sg(struct ata_queued_cmd *qc)
+{
+	struct scatterlist *sg = qc->sg;
+	struct ata_port *ap = qc->ap;
+	struct pdc_port_priv *pp = ap->private_data;
+	void *dimm_mmio = ap->host_set->private_data;
+	unsigned int portno = ap->port_no;
+	unsigned int i, last, idx, total_len = 0;
+	u32 *buf = (u32 *) &pp->prd_buf;
+
+	/*
+	 * Build S/G table
+	 */
+	last = qc->n_elem;
+	idx = 0;
+	for (i = 0; i < last; i++) {
+		buf[idx++] = cpu_to_le32(sg[i].dma_address);
+		buf[idx++] = cpu_to_le32(sg[i].length);
+		total_len += sg[i].length;
+	}
+	idx--;
+	buf[idx] |= cpu_to_le32(ATA_PRD_EOT);
+
+	/*
+	 * Build ATA, host DMA packets
+	 */
+	i = pdc20621_pkt_header(&qc->tf, portno, qc->dev->devno,
+				&pp->pkt_buf[0], total_len);
 
-	ata_fill_sg(qc);
 	if (qc->tf.flags & ATA_TFLAG_LBA48)
-		pdc_prep_lba48(&qc->tf, qc->ap->prd_dma,
-			       qc->dev->devno, pp->pkt);
+		i = pdc_prep_lba48(&qc->tf, &pp->pkt_buf[0], i);
 	else
-		pdc_prep_lba28(&qc->tf, qc->ap->prd_dma,
-			       qc->dev->devno, pp->pkt);
+		i = pdc_prep_lba28(&qc->tf, &pp->pkt_buf[0], i);
+
+	i = pdc_pkt_footer(&qc->tf, &pp->pkt_buf[0], i);
+
+	/* copy two packets and three S/G tables to DIMM MMIO window */
+	memcpy_toio(dimm_mmio + (portno * 1024), &pp->pkt_buf, i);
+	memcpy_toio(dimm_mmio + (4 * 1024) +  (2 * 1024 * portno),
+		    buf, idx * 4);
+}
+
+static void pdc20621_dma_start(struct ata_queued_cmd *qc)
+{
+	struct ata_port *ap = qc->ap;
+	struct ata_host_set *host_set = ap->host_set;
+	unsigned int port_no = ap->port_no;
+	void *mmio = host_set->mmio_base;
+	unsigned int rw = (qc->flags & ATA_QCFLAG_WRITE);
+	u8 seq = (u8) (port_no + 1);
+	u32 pkt_addr;
+	unsigned int doing_hdma = 0;
+
+	/* hard-code chip #0 */
+	mmio += PDC_CHIP0_OFS;
+
+	VPRINTK("ENTER, ap %p, mmio %p\n", ap, mmio);
+
+	/* if writing, we (1) DMA to DIMM, then (2) do ATA command */
+	if (rw) {
+		doing_hdma = 1;
+		seq += 4;
+		pkt_addr = PDC_20621_DIMM_BASE + (4 * port_no);
+	}
+
+	/* if reading, we (1) do ATA command, then (2) DMA from DIMM */
+	else {
+		pkt_addr = PDC_20621_DIMM_BASE + (4 * port_no) + 16;
+	}
+
+	wmb();			/* flush PRD, pkt writes */
+	writel(0x00000001, mmio + PDC_20621_SEQCTL + (seq * 4));
+	if (doing_hdma)
+		writel(pkt_addr, mmio + PDC_HDMA_PKT_SUBMIT);
+	else
+		writel(pkt_addr, (void *) ap->ioaddr.cmd_addr + PDC_PKT_SUBMIT);
+}
+
+static inline unsigned int pdc20621_host_intr( struct ata_port *ap,
+                                          struct ata_queued_cmd *qc,
+					  unsigned int doing_hdma,
+					  void *mmio)
+{
+	unsigned int port_no = ap->port_no;
+	u8 status;
+	unsigned int handled = 0;
+
+	switch (qc->tf.protocol) {
+	case ATA_PROT_DMA_READ:
+		/* step two - DMA from DIMM to host */
+		if (doing_hdma)
+			pdc_dma_complete(ap, qc);
+
+		/* step one - exec ATA command */
+		else {
+			u32 pkt_addr = PDC_20621_DIMM_BASE + (4 * port_no);
+			u8 seq = (u8) (port_no + 1 + 4);
+
+			/* submit hdma pkt */
+			writel(0x00000001, mmio + PDC_20621_SEQCTL + (seq * 4));
+			writel(pkt_addr, mmio + PDC_HDMA_PKT_SUBMIT);
+		}
+		handled = 1;
+		break;
+
+	case ATA_PROT_DMA_WRITE:
+		/* step one - DMA from host to DIMM */
+		if (doing_hdma) {
+			u32 pkt_addr = PDC_20621_DIMM_BASE + (4 * port_no) + 16;
+			u8 seq = (u8) (port_no + 1);
+
+			/* submit ata pkt */
+			writel(0x00000001, mmio + PDC_20621_SEQCTL + (seq * 4));
+			writel(pkt_addr, (void *)
+			       ap->ioaddr.cmd_addr + PDC_PKT_SUBMIT);
+		/* step two - execute ATA command */
+		} else
+			pdc_dma_complete(ap, qc);
+		handled = 1;
+		break;
+
+	case ATA_PROT_NODATA:   /* command completion, but no data xfer */
+		status = ata_busy_wait(ap, ATA_BUSY | ATA_DRQ, 1000);
+		DPRINTK("BUS_NODATA (drv_stat 0x%X)\n", status);
+		ata_qc_complete(qc, status, 0);
+		handled = 1;
+		break;
+
+        default:
+                ap->stats.idle_irq++;
+                break;
+        }
+
+        return handled;
 }
 
-static inline void __pdc_dma_complete (struct ata_port *ap,
-                                       struct ata_queued_cmd *qc)
+static irqreturn_t pdc20621_interrupt (int irq, void *dev_instance, struct pt_regs *regs)
 {
-	void *dmactl = (void *) ap->ioaddr.cmd_addr + PDC_CTLSTAT;
-	u32 val;
+	struct ata_host_set *host_set = dev_instance;
+	struct ata_port *ap;
+	u32 mask = 0;
+	unsigned int i, tmp, port_no;
+	unsigned int handled = 0;
+	void *mmio_base;
+
+	VPRINTK("ENTER\n");
+
+	if (!host_set || !host_set->mmio_base) {
+		VPRINTK("QUICK EXIT\n");
+		return IRQ_NONE;
+	}
+
+	mmio_base = host_set->mmio_base;
+
+	/* reading should also clear interrupts */
+	mmio_base += PDC_CHIP0_OFS;
+	mask = readl(mmio_base + PDC_20621_SEQMASK);
+
+	if (mask == 0xffffffff) {
+		VPRINTK("QUICK EXIT 2\n");
+		return IRQ_NONE;
+	}
+	mask &= 0xf;		/* only 16 tags possible */
+	if (!mask) {
+		VPRINTK("QUICK EXIT 3\n");
+		return IRQ_NONE;
+	}
+
+        spin_lock_irq(&host_set->lock);
+
+        for (i = 1; i < 9; i++) {
+		VPRINTK("port %u\n", port_no);
+		port_no = i - 1;
+		if (port_no > 3)
+			port_no -= 4;
+		if (port_no >= host_set->n_ports)
+			ap = NULL;
+		else
+			ap = host_set->ports[port_no];
+		tmp = mask & (1 << i);
+		if (tmp && ap && (!(ap->flags & ATA_FLAG_PORT_DISABLED))) {
+			struct ata_queued_cmd *qc;
+
+			qc = ata_qc_from_tag(ap, ap->active_tag);
+			if (qc && ((qc->flags & ATA_QCFLAG_POLL) == 0))
+				handled += pdc20621_host_intr(ap, qc, (i > 4),
+							      mmio_base);
+		}
+	}
 
-	/* clear DMA start/stop bit (bit 7) */
-	val = readl(dmactl);
-	writel(val & ~(1 << 7), dmactl);
+        spin_unlock_irq(&host_set->lock);
+
+	VPRINTK("EXIT\n");
 
-	/* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
-	ata_altstatus(ap);              /* dummy read */
+	return IRQ_RETVAL(handled);
+}
+
+static void pdc_fill_sg(struct ata_queued_cmd *qc)
+{
+	struct pdc_port_priv *pp = qc->ap->private_data;
+	unsigned int i;
+
+	ata_fill_sg(qc);
+
+	i = pdc_pkt_header(&qc->tf, qc->ap->prd_dma,  qc->dev->devno, pp->pkt);
+
+	if (qc->tf.flags & ATA_TFLAG_LBA48)
+		i = pdc_prep_lba48(&qc->tf, pp->pkt, i);
+	else
+		i = pdc_prep_lba28(&qc->tf, pp->pkt, i);
+
+	pdc_pkt_footer(&qc->tf, pp->pkt, i);
 }
 
 static inline void pdc_dma_complete (struct ata_port *ap,
                                      struct ata_queued_cmd *qc)
 {
-	__pdc_dma_complete(ap, qc);
-
 	/* get drive status; clear intr; complete txn */
 	ata_qc_complete(ata_qc_from_tag(ap, ap->active_tag),
 			ata_wait_idle(ap), 0);
@@ -470,7 +742,6 @@ static void pdc_eng_timeout(struct ata_port *ap)
 	case ATA_PROT_DMA_READ:
 	case ATA_PROT_DMA_WRITE:
 		printk(KERN_ERR "ata%u: DMA timeout\n", ap->id);
-		__pdc_dma_complete(ap, qc);
 		ata_qc_complete(ata_qc_from_tag(ap, ap->active_tag),
 			        ata_wait_idle(ap) | ATA_ERR, 0);
 		break;
@@ -532,7 +803,7 @@ static irqreturn_t pdc_interrupt (int irq, void *dev_instance, struct pt_regs *r
 	struct ata_port *ap;
 	u32 mask = 0;
 	unsigned int i, tmp;
-	unsigned int handled = 0, have_20621 = 0;
+	unsigned int handled = 0;
 	void *mmio_base;
 
 	VPRINTK("ENTER\n");
@@ -544,21 +815,8 @@ static irqreturn_t pdc_interrupt (int irq, void *dev_instance, struct pt_regs *r
 
 	mmio_base = host_set->mmio_base;
 
-	for (i = 0; i < host_set->n_ports; i++) {
-		ap = host_set->ports[i];
-		if (ap && (ap->flags & PDC_FLAG_20621)) {
-			have_20621 = 1;
-			break;
-		}
-	}
-
 	/* reading should also clear interrupts */
-	if (have_20621) {
-		mmio_base += PDC_CHIP0_OFS;
-		mask = readl(mmio_base + PDC_20621_SEQMASK);
-	} else {
-		mask = readl(mmio_base + PDC_INT_SEQMASK);
-	}
+	mask = readl(mmio_base + PDC_INT_SEQMASK);
 
 	if (mask == 0xffffffff) {
 		VPRINTK("QUICK EXIT 2\n");
@@ -596,20 +854,12 @@ static void pdc_dma_start(struct ata_queued_cmd *qc)
 {
 	struct ata_port *ap = qc->ap;
 	struct pdc_port_priv *pp = ap->private_data;
-	struct ata_host_set *host_set = ap->host_set;
 	unsigned int port_no = ap->port_no;
-	void *mmio = host_set->mmio_base;
 	u8 seq = (u8) (port_no + 1);
 
-	if (ap->flags & PDC_FLAG_20621)
-		mmio += PDC_CHIP0_OFS;
+	VPRINTK("ENTER, ap %p\n", ap);
 
-	VPRINTK("ENTER, ap %p, mmio %p\n", ap, mmio);
-
-	if (ap->flags & PDC_FLAG_20621)
-		writel(0x00000001, mmio + PDC_20621_SEQCTL + (seq * 4));
-	else
-		writel(0x00000001, mmio + (seq * 4));
+	writel(0x00000001, ap->host_set->mmio_base + (seq * 4));
 
 	pp->pkt[2] = seq;
 	wmb();			/* flush PRD, pkt writes */
@@ -648,6 +898,14 @@ static void pdc_sata_setup_port(struct ata_ioports *port, unsigned long base)
 
 static void pdc_20621_init(struct ata_probe_ent *pe)
 {
+	u32 tmp;
+	void *mmio = pe->mmio_base;
+
+	mmio += PDC_CHIP0_OFS;
+
+	tmp = readl(mmio + PDC_20621_DIMM_WINDOW) & 0xffff0000;
+	tmp |= 0x40;	/* page 40h; arbitrarily selected */
+	writel(tmp, mmio + PDC_20621_DIMM_WINDOW);
 }
 
 static void pdc_host_init(unsigned int chip_id, struct ata_probe_ent *pe)
@@ -691,8 +949,9 @@ static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *
 	static int printed_version;
 	struct ata_probe_ent *probe_ent = NULL;
 	unsigned long base;
-	void *mmio_base;
+	void *mmio_base, *dimm_mmio = NULL;
 	unsigned int board_idx = (unsigned int) ent->driver_data;
+	unsigned int have_20621 = (board_idx == board_20621);
 	int rc;
 
 	if (!printed_version++)
@@ -732,6 +991,15 @@ static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *
 	}
 	base = (unsigned long) mmio_base;
 
+	if (have_20621) {
+		dimm_mmio = ioremap(pci_resource_start(pdev, 4),
+				    pci_resource_len(pdev, 4));
+		if (!dimm_mmio) {
+			rc = -ENOMEM;
+			goto err_out_iounmap;
+		}
+	}
+
 	probe_ent->sht		= pdc_port_info[board_idx].sht;
 	probe_ent->host_flags	= pdc_port_info[board_idx].host_flags;
 	probe_ent->pio_mask	= pdc_port_info[board_idx].pio_mask;
@@ -742,8 +1010,10 @@ static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *
        	probe_ent->irq_flags = SA_SHIRQ;
 	probe_ent->mmio_base = mmio_base;
 
-	if (board_idx == board_20621)
+	if (have_20621) {
+		probe_ent->private_data = dimm_mmio;
 		base += PDC_CHIP0_OFS;
+	}
 
 	pdc_sata_setup_port(&probe_ent->port[0], base + 0x200);
 	probe_ent->port[0].scr_addr = base + 0x400;
@@ -774,15 +1044,10 @@ static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *
 	pci_set_master(pdev);
 
 	/* initialize adapter */
-	switch (board_idx) {
-	case board_20621:
+	if (have_20621)
 		pdc_20621_init(probe_ent);
-		break;
-
-	default:
+	else
 		pdc_host_init(board_idx, probe_ent);
-		break;
-	}
 
 	/* FIXME: check ata_device_add return value */
 	ata_device_add(probe_ent);
@@ -790,6 +1055,8 @@ static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *
 
 	return 0;
 
+err_out_iounmap:
+	iounmap(mmio_base);
 err_out_free_ent:
 	kfree(probe_ent);
 err_out_regions:
@@ -800,7 +1067,6 @@ static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *
 }
 
 
-
 static int __init pdc_sata_init(void)
 {
 	int rc;