ssb, b43, b43legacy, b44: Rewrite SSB DMA API

This is a rewrite of the DMA API for SSB devices.
This is needed, because the old (non-existing) "API" made too many bad
assumptions on the API of the host-bus (PCI).
This introduces an almost complete SSB-DMA-API that maps to the lowlevel
bus-API based on the bustype.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

2 files changed, 60 insertions, 17 deletions

diff --git a/drivers/ssb/Kconfig b/drivers/ssb/Kconfig
index cd845b8acd17..307b1f62d949 100644
--- a/drivers/ssb/Kconfig
+++ b/drivers/ssb/Kconfig
@@ -2,7 +2,7 @@ menu "Sonics Silicon Backplane"
 
 config SSB_POSSIBLE
 	bool
-	depends on HAS_IOMEM
+	depends on HAS_IOMEM && HAS_DMA
 	default y
 
 config SSB
diff --git a/drivers/ssb/main.c b/drivers/ssb/main.c
index d184f2aea78d..d831a2beff39 100644
--- a/drivers/ssb/main.c
+++ b/drivers/ssb/main.c
@@ -462,18 +462,15 @@ static int ssb_devices_register(struct ssb_bus *bus)
 #ifdef CONFIG_SSB_PCIHOST
 			sdev->irq = bus->host_pci->irq;
 			dev->parent = &bus->host_pci->dev;
-			sdev->dma_dev = &bus->host_pci->dev;
 #endif
 			break;
 		case SSB_BUSTYPE_PCMCIA:
 #ifdef CONFIG_SSB_PCMCIAHOST
 			sdev->irq = bus->host_pcmcia->irq.AssignedIRQ;
 			dev->parent = &bus->host_pcmcia->dev;
-			sdev->dma_dev = &bus->host_pcmcia->dev;
 #endif
 			break;
 		case SSB_BUSTYPE_SSB:
-			sdev->dma_dev = dev;
 			break;
 		}
 
@@ -1156,36 +1153,82 @@ u32 ssb_dma_translation(struct ssb_device *dev)
 {
 	switch (dev->bus->bustype) {
 	case SSB_BUSTYPE_SSB:
-	case SSB_BUSTYPE_PCMCIA:
 		return 0;
 	case SSB_BUSTYPE_PCI:
 		return SSB_PCI_DMA;
+	default:
+		__ssb_dma_not_implemented(dev);
 	}
 	return 0;
 }
 EXPORT_SYMBOL(ssb_dma_translation);
 
-int ssb_dma_set_mask(struct ssb_device *ssb_dev, u64 mask)
+int ssb_dma_set_mask(struct ssb_device *dev, u64 mask)
 {
-	struct device *dma_dev = ssb_dev->dma_dev;
-	int err = 0;
+	int err;
 
-#ifdef CONFIG_SSB_PCIHOST
-	if (ssb_dev->bus->bustype == SSB_BUSTYPE_PCI) {
-		err = pci_set_dma_mask(ssb_dev->bus->host_pci, mask);
+	switch (dev->bus->bustype) {
+	case SSB_BUSTYPE_PCI:
+		err = pci_set_dma_mask(dev->bus->host_pci, mask);
 		if (err)
 			return err;
-		err = pci_set_consistent_dma_mask(ssb_dev->bus->host_pci, mask);
+		err = pci_set_consistent_dma_mask(dev->bus->host_pci, mask);
 		return err;
+	case SSB_BUSTYPE_SSB:
+		return dma_set_mask(dev->dev, mask);
+	default:
+		__ssb_dma_not_implemented(dev);
 	}
-#endif
-	dma_dev->coherent_dma_mask = mask;
-	dma_dev->dma_mask = &dma_dev->coherent_dma_mask;
-
-	return err;
+	return -ENOSYS;
 }
 EXPORT_SYMBOL(ssb_dma_set_mask);
 
+void * ssb_dma_alloc_consistent(struct ssb_device *dev, size_t size,
+				dma_addr_t *dma_handle, gfp_t gfp_flags)
+{
+	switch (dev->bus->bustype) {
+	case SSB_BUSTYPE_PCI:
+		if (gfp_flags & GFP_DMA) {
+			/* Workaround: The PCI API does not support passing
+			 * a GFP flag. */
+			return dma_alloc_coherent(&dev->bus->host_pci->dev,
+						  size, dma_handle, gfp_flags);
+		}
+		return pci_alloc_consistent(dev->bus->host_pci, size, dma_handle);
+	case SSB_BUSTYPE_SSB:
+		return dma_alloc_coherent(dev->dev, size, dma_handle, gfp_flags);
+	default:
+		__ssb_dma_not_implemented(dev);
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(ssb_dma_alloc_consistent);
+
+void ssb_dma_free_consistent(struct ssb_device *dev, size_t size,
+			     void *vaddr, dma_addr_t dma_handle,
+			     gfp_t gfp_flags)
+{
+	switch (dev->bus->bustype) {
+	case SSB_BUSTYPE_PCI:
+		if (gfp_flags & GFP_DMA) {
+			/* Workaround: The PCI API does not support passing
+			 * a GFP flag. */
+			dma_free_coherent(&dev->bus->host_pci->dev,
+					  size, vaddr, dma_handle);
+			return;
+		}
+		pci_free_consistent(dev->bus->host_pci, size,
+				    vaddr, dma_handle);
+		return;
+	case SSB_BUSTYPE_SSB:
+		dma_free_coherent(dev->dev, size, vaddr, dma_handle);
+		return;
+	default:
+		__ssb_dma_not_implemented(dev);
+	}
+}
+EXPORT_SYMBOL(ssb_dma_free_consistent);
+
 int ssb_bus_may_powerdown(struct ssb_bus *bus)
 {
 	struct ssb_chipcommon *cc;