Addition of MWDMA/UDMA modes to MPC5200 ATA driver

index 1098276..0374322 100644
@@ -16,8 +16,8 @@
 
 struct bcom_ata_bd {
 	u32	status;
-	u32	dst_pa;
 	u32	src_pa;
+	u32	dst_pa;
 };
 
 extern struct bcom_task *

index c960a8b..dc2b143 100644
@@ -38,7 +38,7 @@ struct bcom_task {
 	unsigned int	flags;
 	int		irq;
 
-	struct bcom_bd	*bd;
+	void		*bd;
 	phys_addr_t	bd_pa;
 	void		**cookie;
 	unsigned short	index;

@@ -140,15 +140,29 @@ bcom_queue_full(struct bcom_task *tsk)
 }
 
 /**
+ * bcom_get_bd - Get a BD from the queue
+ * @tsk: The BestComm task structure
+ * index: Index of the BD to fetch
+ */
+static inline struct bcom_bd
+*bcom_get_bd(struct bcom_task *tsk, unsigned int index)
+{
+	return tsk->bd + index * tsk->bd_size;
+}
+
+/**
  * bcom_buffer_done - Checks if a BestComm 
  * @tsk: The BestComm task structure
  */
 static inline int
 bcom_buffer_done(struct bcom_task *tsk)
 {
+	struct bcom_bd *bd;
 	if (bcom_queue_empty(tsk))
 		return 0;
-	return !(tsk->bd[tsk->outdex].status & BCOM_BD_READY);
+
+	bd = bcom_get_bd(tsk, tsk->outdex);
+	return !(bd->status & BCOM_BD_READY);
 }
 
 /**

@@ -160,16 +174,21 @@ bcom_buffer_done(struct bcom_task *tsk)
 static inline struct bcom_bd *
 bcom_prepare_next_buffer(struct bcom_task *tsk)
 {
-	tsk->bd[tsk->index].status = 0;	/* cleanup last status */
-	return &tsk->bd[tsk->index];
+	struct bcom_bd *bd;
+
+	bd = bcom_get_bd(tsk, tsk->index);
+	bd->status = 0;	/* cleanup last status */
+	return bd;
 }
 
 static inline void
 bcom_submit_next_buffer(struct bcom_task *tsk, void *cookie)
 {
+	struct bcom_bd *bd = bcom_get_bd(tsk, tsk->index);
+
 	tsk->cookie[tsk->index] = cookie;
 	mb();	/* ensure the bd is really up-to-date */
-	tsk->bd[tsk->index].status |= BCOM_BD_READY;
+	bd->status |= BCOM_BD_READY;
 	tsk->index = _bcom_next_index(tsk);
 	if (tsk->flags & BCOM_FLAGS_ENABLE_TASK)
 		bcom_enable(tsk);

@@ -179,10 +198,12 @@ static inline void *
 bcom_retrieve_buffer(struct bcom_task *tsk, u32 *p_status, struct bcom_bd **p_bd)
 {
 	void *cookie = tsk->cookie[tsk->outdex];
+	struct bcom_bd *bd = bcom_get_bd(tsk, tsk->outdex);
+
 	if (p_status)
-		*p_status = tsk->bd[tsk->outdex].status;
+		*p_status = bd->status;
 	if (p_bd)
-		*p_bd = &tsk->bd[tsk->outdex];
+		*p_bd = bd;
 	tsk->outdex = _bcom_next_outdex(tsk);
 	return cookie;
 }

index 866a291..746f155 100644
@@ -198,8 +198,8 @@ struct bcom_task_header {
 #define BCOM_IPR_SCTMR_1	2
 #define BCOM_IPR_FEC_RX		6
 #define BCOM_IPR_FEC_TX		5
-#define BCOM_IPR_ATA_RX		4
-#define BCOM_IPR_ATA_TX		3
+#define BCOM_IPR_ATA_RX		7
+#define BCOM_IPR_ATA_TX		7
 #define BCOM_IPR_SCPCI_RX	2
 #define BCOM_IPR_SCPCI_TX	2
 #define BCOM_IPR_PSC3_RX	2

index 1f5258f..901c9f9 100644
@@ -61,6 +61,9 @@ bcom_ata_init(int queue_len, int maxbufsize)
 	struct bcom_ata_var *var;
 	struct bcom_ata_inc *inc;
 
+	/* Prefetch breaks ATA DMA.  Turn it off for ATA DMA */
+	bcom_disable_prefetch();
+
 	tsk = bcom_task_alloc(queue_len, sizeof(struct bcom_ata_bd), 0);
 	if (!tsk)
 		return NULL;

index 446c9ea..378ebd9 100644
@@ -279,7 +279,6 @@ bcom_engine_init(void)
 	int task;
 	phys_addr_t tdt_pa, ctx_pa, var_pa, fdt_pa;
 	unsigned int tdt_size, ctx_size, var_size, fdt_size;
-	u16 regval;
 
 	/* Allocate & clear SRAM zones for FDT, TDTs, contexts and vars/incs */
 	tdt_size = BCOM_MAX_TASKS * sizeof(struct bcom_tdt);

@@ -331,10 +330,8 @@ bcom_engine_init(void)
 	out_8(&bcom_eng->regs->ipr[BCOM_INITIATOR_ALWAYS], BCOM_IPR_ALWAYS);
 
 	/* Disable COMM Bus Prefetch on the original 5200; it's broken */
-	if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) == MPC5200_SVR) {
-		regval = in_be16(&bcom_eng->regs->PtdCntrl);
-		out_be16(&bcom_eng->regs->PtdCntrl,  regval | 1);
-	}
+	if ((mfspr(SPRN_SVR) & MPC5200_SVR_MASK) == MPC5200_SVR)
+		bcom_disable_prefetch();
 
 	/* Init lock */
 	spin_lock_init(&bcom_eng->lock);

index 746f155..eb0d1c8 100644
@@ -241,6 +241,22 @@ extern void bcom_set_initiator(int task, int initiator);
 
 #define TASK_ENABLE             0x8000
 
+/**
+ * bcom_disable_prefetch - Hook to disable bus prefetching
+ *
+ * ATA DMA and the original MPC5200 need this due to silicon bugs.  At the
+ * moment disabling prefetch is a one-way street.  There is no mechanism
+ * in place to turn prefetch back on after it has been disabled.  There is
+ * no reason it couldn't be done, it would just be more complex to implement.
+ */
+static inline void bcom_disable_prefetch(void)
+{
+	u16 regval;
+
+	regval = in_be16(&bcom_eng->regs->PtdCntrl);
+	out_be16(&bcom_eng->regs->PtdCntrl, regval | 1);
+};
+
 static inline void
 bcom_enable_task(int task)
 {

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