[PATCH] Alpha: generic dma mapping

From: Ivan Kokshaysky <ink@jurassic.park.msu.ru>

 - big functions moved out of line;
 - handle dev == NULL case, which apparently means the isa device.

As before, this is needed for Jensen. This also makes the isa sound
drivers working again with recent kernels.

arch/alpha/kernel/alpha_ksyms.c

@@ -18,6 +18,7 @@
 #include <linux/tty.h>
 #include <linux/mm.h>
 #include <linux/delay.h>
+#include <linux/dma-mapping.h>
 
 #include <asm/io.h>
 #include <asm/console.h>
@@ -136,7 +137,9 @@ EXPORT_SYMBOL(pci_dac_dma_supported);
 EXPORT_SYMBOL(pci_dac_page_to_dma);
 EXPORT_SYMBOL(pci_dac_dma_to_page);
 EXPORT_SYMBOL(pci_dac_dma_to_offset);
+EXPORT_SYMBOL(alpha_gendev_to_pci);
 #endif
+EXPORT_SYMBOL(dma_set_mask);
 
 EXPORT_SYMBOL(dump_thread);
 EXPORT_SYMBOL(dump_elf_thread);

arch/alpha/kernel/pci-noop.c

@@ -7,8 +7,10 @@
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/bootmem.h>
+#include <linux/mm.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
+#include <linux/dma-mapping.h>
 
 #include "proto.h"
 
@@ -101,41 +103,100 @@ sys_pciconfig_write(unsigned long bus, unsigned long dfn,
 	else
 		return -ENODEV;
 }
-/* stubs for the routines in pci_iommu.c */
+
+/* Stubs for the routines in pci_iommu.c: */
+
 void *
 pci_alloc_consistent(struct pci_dev *pdev, size_t size, dma_addr_t *dma_addrp)
 {
 	return NULL;
 }
+
 void
 pci_free_consistent(struct pci_dev *pdev, size_t size, void *cpu_addr,
 		    dma_addr_t dma_addr)
 {
 }
+
 dma_addr_t
 pci_map_single(struct pci_dev *pdev, void *cpu_addr, size_t size,
 	       int direction)
 {
 	return (dma_addr_t) 0;
 }
+
 void
 pci_unmap_single(struct pci_dev *pdev, dma_addr_t dma_addr, size_t size,
 		 int direction)
 {
 }
+
 int
 pci_map_sg(struct pci_dev *pdev, struct scatterlist *sg, int nents,
 	   int direction)
 {
 	return 0;
 }
+
 void
 pci_unmap_sg(struct pci_dev *pdev, struct scatterlist *sg, int nents,
 	     int direction)
 {
 }
+
 int
 pci_dma_supported(struct pci_dev *hwdev, dma_addr_t mask)
 {
 	return 0;
 }
+
+/* Generic DMA mapping functions: */
+
+void *
+dma_alloc_coherent(struct device *dev, size_t size,
+		   dma_addr_t *dma_handle, int gfp)
+{
+	void *ret;
+
+	if (!dev || *dev->dma_mask >= 0xffffffffUL)
+		gfp &= ~GFP_DMA;
+	ret = (void *)__get_free_pages(gfp, get_order(size));
+	if (ret) {
+		memset(ret, 0, size);
+		*dma_handle = virt_to_bus(ret);
+	}
+	return ret;
+}
+
+EXPORT_SYMBOL(dma_alloc_coherent);
+
+int
+dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+	   enum dma_data_direction direction)
+{
+	int i;
+
+	for (i = 0; i < nents; i++ ) {
+		void *va;
+
+		BUG_ON(!sg[i].page);
+		va = page_address(sg[i].page) + sg[i].offset;
+		sg_dma_address(sg + i) = (dma_addr_t)virt_to_bus(va);
+		sg_dma_len(sg + i) = sg[i].length;
+	}
+
+	return nents;
+}
+
+EXPORT_SYMBOL(dma_map_sg);
+
+int
+dma_set_mask(struct device *dev, u64 mask)
+{
+	if (!dev->dma_mask || !dma_supported(dev, mask))
+		return -EIO;
+
+	*dev->dma_mask = mask;
+
+	return 0;
+}

arch/alpha/kernel/pci_iommu.c

@@ -930,3 +930,42 @@ pci_dac_dma_to_offset(struct pci_dev *pdev, dma64_addr_t dma_addr)
 {
 	return (dma_addr & ~PAGE_MASK);
 }
+
+
+/* Helper for generic DMA-mapping functions. */
+
+struct pci_dev *
+alpha_gendev_to_pci(struct device *dev)
+{
+	if (dev && dev->bus == &pci_bus_type)
+		return to_pci_dev(dev);
+
+	/* Assume that non-PCI devices asking for DMA are either ISA or EISA,
+	   BUG() otherwise. */
+	BUG_ON(!isa_bridge);
+
+	/* Assume non-busmaster ISA DMA when dma_mask is not set (the ISA
+	   bridge is bus master then). */
+	if (!dev || !dev->dma_mask || !*dev->dma_mask)
+		return isa_bridge;
+
+	/* For EISA bus masters, return isa_bridge (it might have smaller
+	   dma_mask due to wiring limitations). */
+	if (*dev->dma_mask >= isa_bridge->dma_mask)
+		return isa_bridge;
+
+	/* This assumes ISA bus master with dma_mask 0xffffff. */
+	return NULL;
+}
+
+int
+dma_set_mask(struct device *dev, u64 mask)
+{
+	if (!dev->dma_mask ||
+	    !pci_dma_supported(alpha_gendev_to_pci(dev), mask))
+		return -EIO;
+
+	*dev->dma_mask = mask;
+
+	return 0;
+}

include/asm-alpha/cache.h

@@ -20,6 +20,6 @@
 
 #define L1_CACHE_ALIGN(x)  (((x)+(L1_CACHE_BYTES-1))&~(L1_CACHE_BYTES-1))
 #define SMP_CACHE_BYTES    L1_CACHE_BYTES
-#define L1_CACHE_SHIFT_MAX 6	/* largest L1 which this arch supports */
+#define L1_CACHE_SHIFT_MAX L1_CACHE_SHIFT
 
 #endif

include/asm-alpha/dma-mapping.h

-#include <asm-generic/dma-mapping.h>
+#ifndef _ALPHA_DMA_MAPPING_H
+#define _ALPHA_DMA_MAPPING_H
+
+#include <linux/config.h>
+
+#ifdef CONFIG_PCI
+
+#include <linux/pci.h>
+
+#define dma_map_single(dev, va, size, dir)		\
+		pci_map_single(alpha_gendev_to_pci(dev), va, size, dir)
+#define dma_unmap_single(dev, addr, size, dir)		\
+		pci_unmap_single(alpha_gendev_to_pci(dev), addr, size, dir)
+#define dma_alloc_coherent(dev, size, addr, gfp)	\
+		pci_alloc_consistent(alpha_gendev_to_pci(dev), size, addr)
+#define dma_free_coherent(dev, size, va, addr)		\
+		pci_free_consistent(alpha_gendev_to_pci(dev), size, va, addr)
+#define dma_map_page(dev, page, off, size, dir)		\
+		pci_map_single(alpha_gendev_to_pci(dev), page, off, size, dir)
+#define dma_unmap_page(dev, addr, size, dir)		\
+		pci_unmap_page(alpha_gendev_to_pci(dev), addr, size, dir)
+#define dma_map_sg(dev, sg, nents, dir)			\
+		pci_map_sg(alpha_gendev_to_pci(dev), sg, nents, dir)
+#define dma_unmap_sg(dev, sg, nents, dir)		\
+		pci_unmap_sg(alpha_gendev_to_pci(dev), sg, nents, dir)
+#define dma_supported(dev, mask)			\
+		pci_dma_supported(alpha_gendev_to_pci(dev), mask)
+
+#else	/* no PCI - no IOMMU. */
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+			 dma_addr_t *dma_handle, int gfp);
+int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+	       enum dma_data_direction direction);
+
+#define dma_free_coherent(dev, size, va, addr)		\
+		free_pages((unsigned long)va, get_order(size))
+#define dma_supported(dev, mask)		(mask < 0x00ffffffUL ? 0 : 1)
+#define dma_map_single(dev, va, size, dir)	virt_to_phys(va)
+#define dma_map_page(dev, page, off, size, dir)	(page_to_pa(page) + off)
+
+#define dma_unmap_single(dev, addr, size, dir)	do { } while (0)
+#define dma_unmap_page(dev, addr, size, dir)	do { } while (0)
+#define dma_unmap_sg(dev, sg, nents, dir)	do { } while (0)
+
+#endif	/* !CONFIG_PCI */
+
+#define dma_alloc_noncoherent(d, s, h, f)	dma_alloc_coherent(d, s, h, f)
+#define dma_free_noncoherent(d, s, v, h)	dma_free_coherent(d, s, v, h)
+#define dma_is_consistent(dev)			(1)
+
+int dma_set_mask(struct device *dev, u64 mask);
+
+#define dma_sync_single_for_cpu(dev, addr, size, dir)	  do { } while (0)
+#define dma_sync_single_for_device(dev, addr, size, dir)  do { } while (0)
+#define dma_sync_single_range(dev, addr, off, size, dir)  do { } while (0)
+#define dma_sync_sg_for_cpu(dev, sg, nents, dir)	  do { } while (0)
+#define dma_sync_sg_for_device(dev, sg, nents, dir)	  do { } while (0)
+#define dma_cache_sync(va, size, dir)			  do { } while (0)
+
+#define dma_get_cache_alignment()			  L1_CACHE_BYTES
+
+#endif	/* _ALPHA_DMA_MAPPING_H */

include/asm-alpha/pci.h

@@ -246,6 +246,8 @@ pcibios_add_platform_entries(struct pci_dev *dev)
 {
 }
 
+struct pci_dev *alpha_gendev_to_pci(struct device *dev);
+
 #endif /* __KERNEL__ */
 
 /* Values for the `which' argument to sys_pciconfig_iobase.  */