drivers/gpu/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/slab.h>
  41 #include <linux/dma-mapping.h>
  42 #include "drmP.h"
  43
  44 /**********************************************************************/
  45 /** \name PCI memory */
  46 /*@{*/
  47
  48 /**
  49  * \brief Allocate a PCI consistent memory block, for DMA.
  50  */
  51 drm_dma_handle_t *drm_pci_alloc(struct drm_device * dev, size_t size, size_t align)
  52 {
  53         drm_dma_handle_t *dmah;
  54 #if 1
  55         unsigned long addr;
  56         size_t sz;
  57 #endif
  58
  59         /* pci_alloc_consistent only guarantees alignment to the smallest
  60          * PAGE_SIZE order which is greater than or equal to the requested size.
  61          * Return NULL here for now to make sure nobody tries for larger alignment
  62          */
  63         if (align > size)
  64                 return NULL;
  65
  66         dmah = kmalloc(sizeof(drm_dma_handle_t), GFP_KERNEL);
  67         if (!dmah)
  68                 return NULL;
  69
  70         dmah->size = size;
  71         dmah->vaddr = dma_alloc_coherent(&dev->pdev->dev, size, &dmah->busaddr, GFP_KERNEL | __GFP_COMP);
  72
  73         if (dmah->vaddr == NULL) {
  74                 kfree(dmah);
  75                 return NULL;
  76         }
  77
  78         memset(dmah->vaddr, 0, size);
  79
  80         /* XXX - Is virt_to_page() legal for consistent mem? */
  81         /* Reserve */
  82         for (addr = (unsigned long)dmah->vaddr, sz = size;
  83              sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
  84                 SetPageReserved(virt_to_page(addr));
  85         }
  86
  87         return dmah;
  88 }
  89
  90 EXPORT_SYMBOL(drm_pci_alloc);
  91
  92 /**
  93  * \brief Free a PCI consistent memory block without freeing its descriptor.
  94  *
  95  * This function is for internal use in the Linux-specific DRM core code.
  96  */
  97 void __drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
  98 {
  99 #if 1
 100         unsigned long addr;
 101         size_t sz;
 102 #endif
 103
 104         if (dmah->vaddr) {
 105                 /* XXX - Is virt_to_page() legal for consistent mem? */
 106                 /* Unreserve */
 107                 for (addr = (unsigned long)dmah->vaddr, sz = dmah->size;
 108                      sz > 0; addr += PAGE_SIZE, sz -= PAGE_SIZE) {
 109                         ClearPageReserved(virt_to_page(addr));
 110                 }
 111                 dma_free_coherent(&dev->pdev->dev, dmah->size, dmah->vaddr,
 112                                   dmah->busaddr);
 113         }
 114 }
 115
 116 /**
 117  * \brief Free a PCI consistent memory block
 118  */
 119 void drm_pci_free(struct drm_device * dev, drm_dma_handle_t * dmah)
 120 {
 121         __drm_pci_free(dev, dmah);
 122         kfree(dmah);
 123 }
 124
 125 EXPORT_SYMBOL(drm_pci_free);
 126
 127 /*@}*/