drivers/char/drm/drm_pci.c

   1 /* drm_pci.h -- PCI DMA memory management wrappers for DRM -*- linux-c -*- */
   2 /**
   3  * \file drm_pci.c
   4  * \brief Functions and ioctls to manage PCI memory
   5  *
   6  * \warning These interfaces aren't stable yet.
   7  *
   8  * \todo Implement the remaining ioctl's for the PCI pools.
   9  * \todo The wrappers here are so thin that they would be better off inlined..
  10  *
  11  * \author José Fonseca <jrfonseca@tungstengraphics.com>
  12  * \author Leif Delgass <ldelgass@retinalburn.net>
  13  */
  14
  15 /*
  16  * Copyright 2003 José Fonseca.
  17  * Copyright 2003 Leif Delgass.
  18  * All Rights Reserved.
  19  *
  20  * Permission is hereby granted, free of charge, to any person obtaining a
  21  * copy of this software and associated documentation files (the "Software"),
  22  * to deal in the Software without restriction, including without limitation
  23  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  24  * and/or sell copies of the Software, and to permit persons to whom the
  25  * Software is furnished to do so, subject to the following conditions:
  26  *
  27  * The above copyright notice and this permission notice (including the next
  28  * paragraph) shall be included in all copies or substantial portions of the
  29  * Software.
  30  *
  31  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  32  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  33  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  34  * AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  35  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  36  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  37  */
  38
  39 #include <linux/pci.h>
  40 #include <linux/dma-mapping.h>
  41 #include "drmP.h"
  42
  43 /**********************************************************************/
  44 /** \name PCI memory */
  45 /*@{*/
  46
  47 /**
  48  * \brief Allocate a PCI consistent memory block, for DMA.
  49  */
  50 drm_dma_handle_t *drm_pci_alloc(struct drm_device * dev, size_t size, size_t align,
  51                                 dma_addr_t maxaddr)
  52 {
  53         drm_dma_handle_t *dmah;
  54 #if 1
  55         unsigned long addr;
  56         size_t sz;
  57 #endif
  58 #ifdef DRM_DEBUG_MEMORY
  59         int area = DRM_MEM_DMA;
  60
  61         spin_lock(&drm_mem_lock);
  62         if ((drm_ram_used >> PAGE_SHIFT)
  63             > (DRM_RAM_PERCENT * drm_ram_available) / 100) {
  64                 spin_unlock(&drm_mem_lock);
  65                 return 0;
  66         }
  67         spin_unlock(&drm_mem_lock);
  68 #endif
  69
  70         /* pci_alloc_consistent only guarantees alignment to the smallest
  71          * PAGE_SIZE order which is greater than or equal to the requested size.
  72          * Return NULL here for now to make sure nobody tries for larger alignment
  73          */
  74         if (align > size)
  75                 return NULL;
  76
  77         if (pci_set_dma_mask(dev->pdev, maxaddr) != 0) {
  78                 DRM_ERROR("Setting pci dma mask failed\n");
  79                 return NULL;
  80         }
  81
  82         dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
  83         if (!dmah)
  84                 return NULL;
  85
  86         dmah->size = size;
  87         dmah->vaddr = dma_alloc_coherent(&dev->pdev->dev, size, &dmah->busaddr, GFP_KERNEL | __GFP_COMP);
  88
  89 #ifdef DRM_DEBUG_MEMORY
  90         if (dmah->vaddr == NULL) {
  91                 spin_lock(&drm_mem_lock);
  92                 ++drm_mem_stats[area].fail_count;
  93                 spin_unlock(&drm_mem_lock);
  94                 kfree(dmah);
  95                 return NULL;
  96         }
  97
  98         spin_lock(&drm_mem_lock);
  99         ++drm_mem_stats[area].succeed_count;
 100         drm_mem_stats[area].bytes_allocated += size;
 101         drm_ram_used += size;
 102         spin_unlock(&drm_mem_lock);
 103 #else
 104         if (dmah->vaddr == NULL) {
 105                 kfree(dmah);
 106                 return NULL;
 107         }
 108 #endif
 109
 110         memset(dmah->vaddr, 0, size);
 111
 112         /* XXX - Is virt_to_page() legal for consistent mem? */
 113         /* Reserve */
 114         for (addr = (unsigned long)dmah->vaddr, sz = size;
 115              sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
 116                 SetPageReserved(virt_to_page(addr));
 117         }
 118
 119         return dmah;
 120 }
 121
 122 EXPORT_SYMBOL(drm_pci_alloc);
 123
 124 /**
 125  * \brief Free a PCI consistent memory block without freeing its descriptor.
 126  *
 127  * This function is for internal use in the Linux-specific DRM core code.
 128  */
 129 void __drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
 130 {
 131 #if 1
 132         unsigned long addr;
 133         size_t sz;
 134 #endif
 135 #ifdef DRM_DEBUG_MEMORY
 136         int area = DRM_MEM_DMA;
 137         int alloc_count;
 138         int free_count;
 139 #endif
 140
 141         if (!dmah->vaddr) {
 142 #ifdef DRM_DEBUG_MEMORY
 143                 DRM_MEM_ERROR(area, "Attempt to free address 0\n");
 144 #endif
 145         } else {
 146                 /* XXX - Is virt_to_page() legal for consistent mem? */
 147                 /* Unreserve */
 148                 for (addr = (unsigned long)dmah->vaddr, sz = dmah->size;
 149                      sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
 150                         ClearPageReserved(virt_to_page(addr));
 151                 }
 152                 dma_free_coherent(&dev->pdev->dev, dmah->size, dmah->vaddr,
 153                                   dmah->busaddr);
 154         }
 155
 156 #ifdef DRM_DEBUG_MEMORY
 157         spin_lock(&drm_mem_lock);
 158         free_count = ++drm_mem_stats[area].free_count;
 159         alloc_count = drm_mem_stats[area].succeed_count;
 160         drm_mem_stats[area].bytes_freed += size;
 161         drm_ram_used -= size;
 162         spin_unlock(&drm_mem_lock);
 163         if (free_count > alloc_count) {
 164                 DRM_MEM_ERROR(area,
 165                               "Excess frees: %d frees, %d allocs\n",
 166                               free_count, alloc_count);
 167         }
 168 #endif
 169
 170 }
 171
 172 /**
 173  * \brief Free a PCI consistent memory block
 174  */
 175 void drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
 176 {
 177         __drm_pci_free(dev, dmah);
 178         kfree(dmah);
 179 }
 180
 181 EXPORT_SYMBOL(drm_pci_free);
 182
 183 /*@}*/