arch/powerpc/kernel/pci_iommu.c

   1 /*
   2  * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
   3  *
   4  * Rewrite, cleanup, new allocation schemes:
   5  * Copyright (C) 2004 Olof Johansson, IBM Corporation
   6  *
   7  * Dynamic DMA mapping support, platform-independent parts.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  22  */
  23
  24
  25 #include <linux/init.h>
  26 #include <linux/types.h>
  27 #include <linux/slab.h>
  28 #include <linux/mm.h>
  29 #include <linux/spinlock.h>
  30 #include <linux/string.h>
  31 #include <linux/pci.h>
  32 #include <linux/dma-mapping.h>
  33 #include <asm/io.h>
  34 #include <asm/prom.h>
  35 #include <asm/iommu.h>
  36 #include <asm/pci-bridge.h>
  37 #include <asm/machdep.h>
  38 #include <asm/ppc-pci.h>
  39
  40 /*
  41  * We can use ->sysdata directly and avoid the extra work in
  42  * pci_device_to_OF_node since ->sysdata will have been initialised
  43  * in the iommu init code for all devices.
  44  */
  45 #define PCI_GET_DN(dev) ((struct device_node *)((dev)->sysdata))
  46
  47 static inline struct iommu_table *devnode_table(struct device *dev)
  48 {
  49         struct pci_dev *pdev;
  50
  51         if (!dev) {
  52                 pdev = ppc64_isabridge_dev;
  53                 if (!pdev)
  54                         return NULL;
  55         } else
  56                 pdev = to_pci_dev(dev);
  57
  58         return PCI_DN(PCI_GET_DN(pdev))->iommu_table;
  59 }
  60
  61
  62 /* Allocates a contiguous real buffer and creates mappings over it.
  63  * Returns the virtual address of the buffer and sets dma_handle
  64  * to the dma address (mapping) of the first page.
  65  */
  66 static void *pci_iommu_alloc_coherent(struct device *hwdev, size_t size,
  67                            dma_addr_t *dma_handle, gfp_t flag)
  68 {
  69         return iommu_alloc_coherent(devnode_table(hwdev), size, dma_handle,
  70                         flag);
  71 }
  72
  73 static void pci_iommu_free_coherent(struct device *hwdev, size_t size,
  74                          void *vaddr, dma_addr_t dma_handle)
  75 {
  76         iommu_free_coherent(devnode_table(hwdev), size, vaddr, dma_handle);
  77 }
  78
  79 /* Creates TCEs for a user provided buffer.  The user buffer must be
  80  * contiguous real kernel storage (not vmalloc).  The address of the buffer
  81  * passed here is the kernel (virtual) address of the buffer.  The buffer
  82  * need not be page aligned, the dma_addr_t returned will point to the same
  83  * byte within the page as vaddr.
  84  */
  85 static dma_addr_t pci_iommu_map_single(struct device *hwdev, void *vaddr,
  86                 size_t size, enum dma_data_direction direction)
  87 {
  88         return iommu_map_single(devnode_table(hwdev), vaddr, size, direction);
  89 }
  90
  91
  92 static void pci_iommu_unmap_single(struct device *hwdev, dma_addr_t dma_handle,
  93                 size_t size, enum dma_data_direction direction)
  94 {
  95         iommu_unmap_single(devnode_table(hwdev), dma_handle, size, direction);
  96 }
  97
  98
  99 static int pci_iommu_map_sg(struct device *pdev, struct scatterlist *sglist,
 100                 int nelems, enum dma_data_direction direction)
 101 {
 102         return iommu_map_sg(pdev, devnode_table(pdev), sglist,
 103                         nelems, direction);
 104 }
 105
 106 static void pci_iommu_unmap_sg(struct device *pdev, struct scatterlist *sglist,
 107                 int nelems, enum dma_data_direction direction)
 108 {
 109         iommu_unmap_sg(devnode_table(pdev), sglist, nelems, direction);
 110 }
 111
 112 /* We support DMA to/from any memory page via the iommu */
 113 static int pci_iommu_dma_supported(struct device *dev, u64 mask)
 114 {
 115         return 1;
 116 }
 117
 118 void pci_iommu_init(void)
 119 {
 120         pci_dma_ops.alloc_coherent = pci_iommu_alloc_coherent;
 121         pci_dma_ops.free_coherent = pci_iommu_free_coherent;
 122         pci_dma_ops.map_single = pci_iommu_map_single;
 123         pci_dma_ops.unmap_single = pci_iommu_unmap_single;
 124         pci_dma_ops.map_sg = pci_iommu_map_sg;
 125         pci_dma_ops.unmap_sg = pci_iommu_unmap_sg;
 126         pci_dma_ops.dma_supported = pci_iommu_dma_supported;
 127 }