arch/ppc64/kernel/pci_iommu.c

   1 /*
   2  * arch/ppc64/kernel/pci_iommu.c
   3  * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
   4  *
   5  * Rewrite, cleanup, new allocation schemes:
   6  * Copyright (C) 2004 Olof Johansson, IBM Corporation
   7  *
   8  * Dynamic DMA mapping support, platform-independent parts.
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  23  */
  24
  25
  26 #include <linux/init.h>
  27 #include <linux/types.h>
  28 #include <linux/slab.h>
  29 #include <linux/mm.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/string.h>
  32 #include <linux/pci.h>
  33 #include <linux/dma-mapping.h>
  34 #include <asm/io.h>
  35 #include <asm/prom.h>
  36 #include <asm/iommu.h>
  37 #include <asm/pci-bridge.h>
  38 #include <asm/machdep.h>
  39 #include <asm/ppc-pci.h>
  40
  41 /*
  42  * We can use ->sysdata directly and avoid the extra work in
  43  * pci_device_to_OF_node since ->sysdata will have been initialised
  44  * in the iommu init code for all devices.
  45  */
  46 #define PCI_GET_DN(dev) ((struct device_node *)((dev)->sysdata))
  47
  48 static inline struct iommu_table *devnode_table(struct device *dev)
  49 {
  50         struct pci_dev *pdev;
  51
  52         if (!dev) {
  53                 pdev = ppc64_isabridge_dev;
  54                 if (!pdev)
  55                         return NULL;
  56         } else
  57                 pdev = to_pci_dev(dev);
  58
  59         return PCI_DN(PCI_GET_DN(pdev))->iommu_table;
  60 }
  61
  62
  63 /* Allocates a contiguous real buffer and creates mappings over it.
  64  * Returns the virtual address of the buffer and sets dma_handle
  65  * to the dma address (mapping) of the first page.
  66  */
  67 static void *pci_iommu_alloc_coherent(struct device *hwdev, size_t size,
  68                            dma_addr_t *dma_handle, gfp_t flag)
  69 {
  70         return iommu_alloc_coherent(devnode_table(hwdev), size, dma_handle,
  71                         flag);
  72 }
  73
  74 static void pci_iommu_free_coherent(struct device *hwdev, size_t size,
  75                          void *vaddr, dma_addr_t dma_handle)
  76 {
  77         iommu_free_coherent(devnode_table(hwdev), size, vaddr, dma_handle);
  78 }
  79
  80 /* Creates TCEs for a user provided buffer.  The user buffer must be
  81  * contiguous real kernel storage (not vmalloc).  The address of the buffer
  82  * passed here is the kernel (virtual) address of the buffer.  The buffer
  83  * need not be page aligned, the dma_addr_t returned will point to the same
  84  * byte within the page as vaddr.
  85  */
  86 static dma_addr_t pci_iommu_map_single(struct device *hwdev, void *vaddr,
  87                 size_t size, enum dma_data_direction direction)
  88 {
  89         return iommu_map_single(devnode_table(hwdev), vaddr, size, direction);
  90 }
  91
  92
  93 static void pci_iommu_unmap_single(struct device *hwdev, dma_addr_t dma_handle,
  94                 size_t size, enum dma_data_direction direction)
  95 {
  96         iommu_unmap_single(devnode_table(hwdev), dma_handle, size, direction);
  97 }
  98
  99
 100 static int pci_iommu_map_sg(struct device *pdev, struct scatterlist *sglist,
 101                 int nelems, enum dma_data_direction direction)
 102 {
 103         return iommu_map_sg(pdev, devnode_table(pdev), sglist,
 104                         nelems, direction);
 105 }
 106
 107 static void pci_iommu_unmap_sg(struct device *pdev, struct scatterlist *sglist,
 108                 int nelems, enum dma_data_direction direction)
 109 {
 110         iommu_unmap_sg(devnode_table(pdev), sglist, nelems, direction);
 111 }
 112
 113 /* We support DMA to/from any memory page via the iommu */
 114 static int pci_iommu_dma_supported(struct device *dev, u64 mask)
 115 {
 116         return 1;
 117 }
 118
 119 void pci_iommu_init(void)
 120 {
 121         pci_dma_ops.alloc_coherent = pci_iommu_alloc_coherent;
 122         pci_dma_ops.free_coherent = pci_iommu_free_coherent;
 123         pci_dma_ops.map_single = pci_iommu_map_single;
 124         pci_dma_ops.unmap_single = pci_iommu_unmap_single;
 125         pci_dma_ops.map_sg = pci_iommu_map_sg;
 126         pci_dma_ops.unmap_sg = pci_iommu_unmap_sg;
 127         pci_dma_ops.dma_supported = pci_iommu_dma_supported;
 128 }