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 Jose Fonseca <jrfonseca@tungstengraphics.com>
  12  * \author Leif Delgass <ldelgass@retinalburn.net>
  13  */
  14
  15 /*
  16  * Copyright 2003 Jos�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 "drmP.h"
  41
  42 /**********************************************************************/
  43 /** \name PCI memory */
  44 /*@{*/
  45
  46 /**
  47  * \brief Allocate a PCI consistent memory block, for DMA.
  48  */
  49 drm_dma_handle_t *drm_pci_alloc(drm_device_t * dev, size_t size, size_t align,
  50                                 dma_addr_t maxaddr)
  51 {
  52         drm_dma_handle_t *dmah;
  53 #ifdef DRM_DEBUG_MEMORY
  54         int area = DRM_MEM_DMA;
  55
  56         spin_lock(&drm_mem_lock);
  57         if ((drm_ram_used >> PAGE_SHIFT)
  58             > (DRM_RAM_PERCENT * drm_ram_available) / 100) {
  59                 spin_unlock(&drm_mem_lock);
  60                 return 0;
  61         }
  62         spin_unlock(&drm_mem_lock);
  63 #endif
  64
  65         /* pci_alloc_consistent only guarantees alignment to the smallest
  66          * PAGE_SIZE order which is greater than or equal to the requested size.
  67          * Return NULL here for now to make sure nobody tries for larger alignment
  68          */
  69         if (align > size)
  70                 return NULL;
  71
  72         if (pci_set_dma_mask(dev->pdev, maxaddr) != 0) {
  73                 DRM_ERROR("Setting pci dma mask failed\n");
  74                 return NULL;
  75         }
  76
  77         dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
  78         if (!dmah)
  79                 return NULL;
  80
  81         dmah->size = size;
  82         dmah->vaddr = pci_alloc_consistent(dev->pdev, size, &dmah->busaddr);
  83
  84 #ifdef DRM_DEBUG_MEMORY
  85         if (dmah->vaddr == NULL) {
  86                 spin_lock(&drm_mem_lock);
  87                 ++drm_mem_stats[area].fail_count;
  88                 spin_unlock(&drm_mem_lock);
  89                 kfree(dmah);
  90                 return NULL;
  91         }
  92
  93         spin_lock(&drm_mem_lock);
  94         ++drm_mem_stats[area].succeed_count;
  95         drm_mem_stats[area].bytes_allocated += size;
  96         drm_ram_used += size;
  97         spin_unlock(&drm_mem_lock);
  98 #else
  99         if (dmah->vaddr == NULL) {
 100                 kfree(dmah);
 101                 return NULL;
 102         }
 103 #endif
 104
 105         memset(dmah->vaddr, 0, size);
 106
 107         return dmah;
 108 }
 109 EXPORT_SYMBOL(drm_pci_alloc);
 110
 111 /**
 112  * \brief Free a PCI consistent memory block with freeing its descriptor.
 113  *
 114  * This function is for internal use in the Linux-specific DRM core code.
 115  */
 116 void
 117 __drm_pci_free(drm_device_t * dev, drm_dma_handle_t *dmah)
 118 {
 119 #ifdef DRM_DEBUG_MEMORY
 120         int area = DRM_MEM_DMA;
 121         int alloc_count;
 122         int free_count;
 123 #endif
 124
 125         if (!dmah->vaddr) {
 126 #ifdef DRM_DEBUG_MEMORY
 127                 DRM_MEM_ERROR(area, "Attempt to free address 0\n");
 128 #endif
 129         } else {
 130                 pci_free_consistent(dev->pdev, dmah->size, dmah->vaddr,
 131                                     dmah->busaddr);
 132         }
 133
 134 #ifdef DRM_DEBUG_MEMORY
 135         spin_lock(&drm_mem_lock);
 136         free_count = ++drm_mem_stats[area].free_count;
 137         alloc_count = drm_mem_stats[area].succeed_count;
 138         drm_mem_stats[area].bytes_freed += size;
 139         drm_ram_used -= size;
 140         spin_unlock(&drm_mem_lock);
 141         if (free_count > alloc_count) {
 142                 DRM_MEM_ERROR(area,
 143                               "Excess frees: %d frees, %d allocs\n",
 144                               free_count, alloc_count);
 145         }
 146 #endif
 147
 148 }
 149
 150 /**
 151  * \brief Free a PCI consistent memory block
 152  */
 153 void
 154 drm_pci_free(drm_device_t *dev, drm_dma_handle_t *dmah)
 155 {
 156         __drm_pci_free(dev, dmah);
 157         kfree(dmah);
 158 }
 159 EXPORT_SYMBOL(drm_pci_free);
 160
 161 /*@}*/