[libata promise] fix another ugly bug

For the SX4, only one Host DMA (local DIMM) engine is on the hardware,
while there is an ATA engine for each SATA port.  This means that
Host DMA transactions must be queued.  When previously fixing this problem
(the driver had previously assumed an HDMA engine per port), I stored
the HDMA packet queue in a per-port data structure.

This was incorrect:  this patch changes it to correctly use a
per-host data structure, not a per-port structure.

drivers/scsi/sata_promise.c

@@ -35,7 +35,7 @@
 #include <asm/io.h>
 
 #define DRV_NAME	"sata_promise"
-#define DRV_VERSION	"0.88"
+#define DRV_VERSION	"0.89"
 
 
 enum {
@@ -123,6 +123,10 @@ struct pdc_port_priv {
 	u8			dimm_buf[(ATA_PRD_SZ * ATA_MAX_PRD) + 512];
 	u8			*pkt;
 	dma_addr_t		pkt_dma;
+};
+
+struct pdc_host_priv {
+	void			*dimm_mmio;
 
 	unsigned int		doing_hdma;
 	unsigned int		hdma_prod;
@@ -291,10 +295,11 @@ 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;
+	struct pdc_host_priv *hpriv = host_set->private_data;
+	void *dimm_mmio = hpriv->dimm_mmio;
 
-	assert(mmio != NULL);
-	iounmap(mmio);
+	iounmap(dimm_mmio);
+	kfree(hpriv);
 }
 
 static int pdc_port_start(struct ata_port *ap)
@@ -646,7 +651,8 @@ static void pdc20621_fill_sg(struct ata_queued_cmd *qc)
 	struct ata_port *ap = qc->ap;
 	struct pdc_port_priv *pp = ap->private_data;
 	void *mmio = ap->host_set->mmio_base;
-	void *dimm_mmio = ap->host_set->private_data;
+	struct pdc_host_priv *hpriv = ap->host_set->private_data;
+	void *dimm_mmio = hpriv->dimm_mmio;
 	unsigned int portno = ap->port_no;
 	unsigned int i, last, idx, total_len = 0, sgt_len;
 	u32 *buf = (u32 *) &pp->dimm_buf[PDC_DIMM_HEADER_SZ];
@@ -723,7 +729,7 @@ static void pdc20621_push_hdma(struct ata_queued_cmd *qc,
 				u32 pkt_ofs)
 {
 	struct ata_port *ap = qc->ap;
-	struct pdc_port_priv *pp = ap->private_data;
+	struct pdc_host_priv *pp = ap->host_set->private_data;
 	unsigned int idx = pp->hdma_prod & PDC_HDMA_Q_MASK;
 
 	if (!pp->doing_hdma) {
@@ -741,7 +747,7 @@ static void pdc20621_push_hdma(struct ata_queued_cmd *qc,
 static void pdc20621_pop_hdma(struct ata_queued_cmd *qc)
 {
 	struct ata_port *ap = qc->ap;
-	struct pdc_port_priv *pp = ap->private_data;
+	struct pdc_host_priv *pp = ap->host_set->private_data;
 	unsigned int idx = pp->hdma_cons & PDC_HDMA_Q_MASK;
 
 	/* if nothing on queue, we're done */
@@ -760,7 +766,8 @@ static void pdc20621_dump_hdma(struct ata_queued_cmd *qc)
 {
 	struct ata_port *ap = qc->ap;
 	unsigned int port_no = ap->port_no;
-	void *dimm_mmio = ap->host_set->private_data;
+	struct pdc_host_priv *hpriv = ap->host_set->private_data;
+	void *dimm_mmio = hpriv->dimm_mmio;
 
 	dimm_mmio += (port_no * PDC_DIMM_WINDOW_STEP);
 	dimm_mmio += PDC_DIMM_HOST_PKT;
@@ -1172,7 +1179,8 @@ static void pdc20621_get_from_dimm(struct ata_probe_ent *pe, void *psource,
 	u8 page_mask;
 	long dist;
 	void *mmio = pe->mmio_base;
-	void *dimm_mmio = pe->private_data;
+	struct pdc_host_priv *hpriv = pe->private_data;
+	void *dimm_mmio = hpriv->dimm_mmio;
 
 	/* hard-code chip #0 */
 	mmio += PDC_CHIP0_OFS;
@@ -1227,7 +1235,8 @@ static void pdc20621_put_to_dimm(struct ata_probe_ent *pe, void *psource,
 	u8 page_mask;
 	long dist;
 	void *mmio = pe->mmio_base;
-	void *dimm_mmio = pe->private_data;
+	struct pdc_host_priv *hpriv = pe->private_data;
+	void *dimm_mmio = hpriv->dimm_mmio;
 
 	/* hard-code chip #0 */   
 	mmio += PDC_CHIP0_OFS;
@@ -1594,6 +1603,7 @@ static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *
 	struct ata_probe_ent *probe_ent = NULL;
 	unsigned long base;
 	void *mmio_base, *dimm_mmio = NULL;
+	struct pdc_host_priv *hpriv = NULL;
 	unsigned int board_idx = (unsigned int) ent->driver_data;
 	unsigned int have_20621 = (board_idx == board_20621);
 	int rc;
@@ -1636,12 +1646,22 @@ static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *
 	base = (unsigned long) mmio_base;
 
 	if (have_20621) {
+		hpriv = kmalloc(sizeof(*hpriv), GFP_KERNEL);
+		if (!hpriv) {
+			rc = -ENOMEM;
+			goto err_out_iounmap;
+		}
+		memset(hpriv, 0, sizeof(*hpriv));
+
 		dimm_mmio = ioremap(pci_resource_start(pdev, 4),
 				    pci_resource_len(pdev, 4));
 		if (!dimm_mmio) {
+			kfree(hpriv);
 			rc = -ENOMEM;
 			goto err_out_iounmap;
 		}
+
+		hpriv->dimm_mmio = dimm_mmio;
 	}
 
 	probe_ent->sht		= pdc_port_info[board_idx].sht;
@@ -1655,7 +1675,7 @@ static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *
 	probe_ent->mmio_base = mmio_base;
 
 	if (have_20621) {
-		probe_ent->private_data = dimm_mmio;
+		probe_ent->private_data = hpriv;
 		base += PDC_CHIP0_OFS;
 	}
 
@@ -1696,7 +1716,7 @@ static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *
 		/* initialize local dimm */
 		if (pdc20621_dimm_init(probe_ent)) {
 			rc = -ENOMEM;
-			goto err_out_iounmap;
+			goto err_out_iounmap_dimm;
 		}
 		pdc_20621_init(probe_ent);
 	} else
@@ -1708,6 +1728,9 @@ static int pdc_sata_init_one (struct pci_dev *pdev, const struct pci_device_id *
 
 	return 0;
 
+err_out_iounmap_dimm:		/* only get to this label if 20621 */
+	kfree(hpriv);
+	iounmap(dimm_mmio);
 err_out_iounmap:
 	iounmap(mmio_base);
 err_out_free_ent: