ide: switch to DMA-mapping API part #2

Follow-up to commit 5c05ff68b9a9b40a9be949497e0aa980185565cf
("ide: switch to DMA-mapping API"):

* pci_{alloc,free}_consistent() -> dma_{alloc,free}_coherent()
  in ide_{allocate,release}_dma_engine().

* Add ->prd_max_nents and ->prd_ent_size fields to ide_hwif_t
  (+ set default values in ide_allocate_dma_engine()).

* Make ide_{allocate,release}_dma_engine() available also
  for CONFIG_BLK_DEV_IDEDMA_SFF=n.  Then convert au1xxx-ide.c,
  scc_pata.c and sgiioc4.c to use them.

* Add missing ->init_dma method to scc_pata.

This patch also fixes:
- ->dmatable_cpu leak for au1xxx-ide
- too early realease of ->dmatable_cpu for scc_pata
- wrong amount of ->dmatable_cpu memory being freed for sgiioc4

While at it:
- remove superfluous ->dma_base check from ide_unregister()
- return -ENOMEM on error in ide_release_dma_engine()
- beautify error message in ide_release_dma_engine()

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-dma.c

@@ -844,36 +844,43 @@ void ide_dma_timeout(ide_drive_t *drive)
 }
 EXPORT_SYMBOL_GPL(ide_dma_timeout);
 
-#ifdef CONFIG_BLK_DEV_IDEDMA_SFF
 void ide_release_dma_engine(ide_hwif_t *hwif)
 {
 	if (hwif->dmatable_cpu) {
-		struct pci_dev *pdev = to_pci_dev(hwif->dev);
+		int prd_size = hwif->prd_max_nents * hwif->prd_ent_size;
 
-		pci_free_consistent(pdev, PRD_ENTRIES * PRD_BYTES,
-				    hwif->dmatable_cpu, hwif->dmatable_dma);
+		dma_free_coherent(hwif->dev, prd_size,
+				  hwif->dmatable_cpu, hwif->dmatable_dma);
 		hwif->dmatable_cpu = NULL;
 	}
 }
+EXPORT_SYMBOL_GPL(ide_release_dma_engine);
 
 int ide_allocate_dma_engine(ide_hwif_t *hwif)
 {
-	struct pci_dev *pdev = to_pci_dev(hwif->dev);
+	int prd_size;
 
-	hwif->dmatable_cpu = pci_alloc_consistent(pdev,
-						  PRD_ENTRIES * PRD_BYTES,
-						  &hwif->dmatable_dma);
+	if (hwif->prd_max_nents == 0)
+		hwif->prd_max_nents = PRD_ENTRIES;
+	if (hwif->prd_ent_size == 0)
+		hwif->prd_ent_size = PRD_BYTES;
 
-	if (hwif->dmatable_cpu)
-		return 0;
+	prd_size = hwif->prd_max_nents * hwif->prd_ent_size;
 
-	printk(KERN_ERR "%s: -- Error, unable to allocate DMA table.\n",
+	hwif->dmatable_cpu = dma_alloc_coherent(hwif->dev, prd_size,
+						&hwif->dmatable_dma,
+						GFP_ATOMIC);
+	if (hwif->dmatable_cpu == NULL) {
+		printk(KERN_ERR "%s: unable to allocate PRD table\n",
 			hwif->name);
+		return -ENOMEM;
+	}
 
-	return 1;
+	return 0;
 }
 EXPORT_SYMBOL_GPL(ide_allocate_dma_engine);
 
+#ifdef CONFIG_BLK_DEV_IDEDMA_SFF
 const struct ide_dma_ops sff_dma_ops = {
 	.dma_host_set		= ide_dma_host_set,
 	.dma_setup		= ide_dma_setup,

drivers/ide/ide.c

@@ -227,8 +227,7 @@ void ide_unregister(ide_hwif_t *hwif)
 	kfree(hwif->sg_table);
 	unregister_blkdev(hwif->major, hwif->name);
 
-	if (hwif->dma_base)
-		ide_release_dma_engine(hwif);
+	ide_release_dma_engine(hwif);
 
 	mutex_unlock(&ide_cfg_mtx);
 }

drivers/ide/mips/au1xxx-ide.c

@@ -427,10 +427,9 @@ static int auide_ddma_init(ide_hwif_t *hwif, const struct ide_port_info *d)
 							     NUM_DESCRIPTORS);
 	auide->rx_desc_head = (void*)au1xxx_dbdma_ring_alloc(auide->rx_chan,
 							     NUM_DESCRIPTORS);
- 
-	hwif->dmatable_cpu = dma_alloc_coherent(hwif->dev,
-						PRD_ENTRIES * PRD_BYTES,        /* 1 Page */
-						&hwif->dmatable_dma, GFP_KERNEL);
+
+	/* FIXME: check return value */
+	(void)ide_allocate_dma_engine(hwif);
 	
 	au1xxx_dbdma_start( auide->tx_chan );
 	au1xxx_dbdma_start( auide->rx_chan );

drivers/ide/pci/scc_pata.c

@@ -821,6 +821,12 @@ static void __devinit init_iops_scc(ide_hwif_t *hwif)
 	init_mmio_iops_scc(hwif);
 }
 
+static int __devinit scc_init_dma(ide_hwif_t *hwif,
+				  const struct ide_port_info *d)
+{
+	return ide_allocate_dma_engine(hwif);
+}
+
 static u8 scc_cable_detect(ide_hwif_t *hwif)
 {
 	return ATA_CBL_PATA80;
@@ -885,6 +891,7 @@ static const struct ide_dma_ops scc_dma_ops = {
   {							\
       .name		= name_str,			\
       .init_iops	= init_iops_scc,		\
+      .init_dma		= scc_init_dma,			\
       .init_hwif	= init_hwif_scc,		\
       .tp_ops		= &scc_tp_ops,		\
       .port_ops		= &scc_port_ops,		\
@@ -922,13 +929,6 @@ static void __devexit scc_remove(struct pci_dev *dev)
 {
 	struct scc_ports *ports = pci_get_drvdata(dev);
 	struct ide_host *host = ports->host;
-	ide_hwif_t *hwif = host->ports[0];
-
-	if (hwif->dmatable_cpu) {
-		pci_free_consistent(dev, PRD_ENTRIES * PRD_BYTES,
-				    hwif->dmatable_cpu, hwif->dmatable_dma);
-		hwif->dmatable_cpu = NULL;
-	}
 
 	ide_host_remove(host);
 

drivers/ide/pci/sgiioc4.c

@@ -357,14 +357,13 @@ ide_dma_sgiioc4(ide_hwif_t *hwif, const struct ide_port_info *d)
 	}
 	hwif->dma_base = (unsigned long) virt_dma_base;
 
-	hwif->dmatable_cpu = pci_alloc_consistent(dev,
-					  IOC4_PRD_ENTRIES * IOC4_PRD_BYTES,
-					  &hwif->dmatable_dma);
+	hwif->sg_max_nents = IOC4_PRD_ENTRIES;
 
-	if (!hwif->dmatable_cpu)
-		goto dma_pci_alloc_failure;
+	hwif->prd_max_nents = IOC4_PRD_ENTRIES;
+	hwif->prd_ent_size = IOC4_PRD_BYTES;
 
-	hwif->sg_max_nents = IOC4_PRD_ENTRIES;
+	if (ide_allocate_dma_engine(hwif))
+		goto dma_pci_alloc_failure;
 
 	pad = pci_alloc_consistent(dev, IOC4_IDE_CACHELINE_SIZE,
 				   (dma_addr_t *)&hwif->extra_base);
@@ -373,8 +372,8 @@ ide_dma_sgiioc4(ide_hwif_t *hwif, const struct ide_port_info *d)
 		return 0;
 	}
 
-	pci_free_consistent(dev, IOC4_PRD_ENTRIES * IOC4_PRD_BYTES,
-			    hwif->dmatable_cpu, hwif->dmatable_dma);
+	ide_release_dma_engine(hwif);
+
 	printk(KERN_ERR "%s(%s) -- ERROR: Unable to allocate DMA maps\n",
 	       __func__, hwif->name);
 	printk(KERN_INFO "%s: changing from DMA to PIO mode", hwif->name);

include/linux/ide.h

@@ -788,6 +788,12 @@ typedef struct hwif_s {
 	unsigned int	*dmatable_cpu;
 	/* dma physical region descriptor table (dma view) */
 	dma_addr_t	dmatable_dma;
+
+	/* maximum number of PRD table entries */
+	int prd_max_nents;
+	/* PRD entry size in bytes */
+	int prd_ent_size;
+
 	/* Scatter-gather list used to build the above */
 	struct scatterlist *sg_table;
 	int sg_max_nents;		/* Maximum number of entries in it */
@@ -1423,14 +1429,14 @@ int ide_set_dma(ide_drive_t *);
 void ide_check_dma_crc(ide_drive_t *);
 ide_startstop_t ide_dma_intr(ide_drive_t *);
 
+int ide_allocate_dma_engine(ide_hwif_t *);
+void ide_release_dma_engine(ide_hwif_t *);
+
 int ide_build_sglist(ide_drive_t *, struct request *);
 void ide_destroy_dmatable(ide_drive_t *);
 
 #ifdef CONFIG_BLK_DEV_IDEDMA_SFF
 extern int ide_build_dmatable(ide_drive_t *, struct request *);
-int ide_allocate_dma_engine(ide_hwif_t *);
-void ide_release_dma_engine(ide_hwif_t *);
-
 void ide_dma_host_set(ide_drive_t *, int);
 extern int ide_dma_setup(ide_drive_t *);
 void ide_dma_exec_cmd(ide_drive_t *, u8);
@@ -1453,11 +1459,8 @@ static inline void ide_dma_on(ide_drive_t *drive) { ; }
 static inline void ide_dma_verbose(ide_drive_t *drive) { ; }
 static inline int ide_set_dma(ide_drive_t *drive) { return 1; }
 static inline void ide_check_dma_crc(ide_drive_t *drive) { ; }
-#endif /* CONFIG_BLK_DEV_IDEDMA */
-
-#ifndef CONFIG_BLK_DEV_IDEDMA_SFF
 static inline void ide_release_dma_engine(ide_hwif_t *hwif) { ; }
-#endif
+#endif /* CONFIG_BLK_DEV_IDEDMA */
 
 #ifdef CONFIG_BLK_DEV_IDEACPI
 extern int ide_acpi_exec_tfs(ide_drive_t *drive);