sys/dev/drm/drm_pci.c

   1 /*-
   2  * Copyright 2003 Eric Anholt.
   3  * All Rights Reserved.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  19  * AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  21  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 /**
  25  * \file drm_pci.h
  26  * \brief PCI consistent, DMA-accessible memory allocation.
  27  *
  28  * \author Eric Anholt <anholt@FreeBSD.org>
  29  */
  30
  31 #include "dev/drm/drmP.h"
  32
  33 /**********************************************************************/
  34 /** \name PCI memory */
  35 /*@{*/
  36
  37 static void
  38 drm_pci_busdma_callback(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
  39 {
  40         drm_dma_handle_t *dmah = arg;
  41
  42         if (error != 0)
  43                 return;
  44
  45         KASSERT(nsegs == 1, ("drm_pci_busdma_callback: bad dma segment count"));
  46         dmah->busaddr = segs[0].ds_addr;
  47 }
  48
  49 /**
  50  * \brief Allocate a physically contiguous DMA-accessible consistent
  51  * memory block.
  52  */
  53 drm_dma_handle_t *
  54 drm_pci_alloc(struct drm_device *dev, size_t size,
  55               size_t align, dma_addr_t maxaddr)
  56 {
  57         drm_dma_handle_t *dmah;
  58         int ret;
  59
  60         /* Need power-of-two alignment, so fail the allocation if it isn't. */
  61         if ((align & (align - 1)) != 0) {
  62                 DRM_ERROR("drm_pci_alloc with non-power-of-two alignment %d\n",
  63                     (int)align);
  64                 return NULL;
  65         }
  66
  67         dmah = malloc(sizeof(drm_dma_handle_t), DRM_MEM_DMA, M_ZERO | M_NOWAIT);
  68         if (dmah == NULL)
  69                 return NULL;
  70
  71 #if 0 /* HT XXX XXX XXX */
  72         /* Make sure we aren't holding locks here */
  73         mtx_assert(&dev->dev_lock, MA_NOTOWNED);
  74         if (mtx_owned(&dev->dev_lock))
  75             DRM_ERROR("called while holding dev_lock\n");
  76         mtx_assert(&dev->dma_lock, MA_NOTOWNED);
  77         if (mtx_owned(&dev->dma_lock))
  78             DRM_ERROR("called while holding dma_lock\n");
  79 #endif
  80
  81         ret = bus_dma_tag_create(NULL, align, 0, /* tag, align, boundary */
  82             maxaddr, BUS_SPACE_MAXADDR, /* lowaddr, highaddr */
  83             NULL, NULL, /* filtfunc, filtfuncargs */
  84             size, 1, size, /* maxsize, nsegs, maxsegsize */
  85             0, /* flags */
  86             &dmah->tag);
  87         if (ret != 0) {
  88                 free(dmah, DRM_MEM_DMA);
  89                 return NULL;
  90         }
  91
  92         /* XXX BUS_DMA_NOCACHE */
  93         ret = bus_dmamem_alloc(dmah->tag, &dmah->vaddr,
  94             BUS_DMA_WAITOK | BUS_DMA_ZERO, &dmah->map);
  95         if (ret != 0) {
  96                 bus_dma_tag_destroy(dmah->tag);
  97                 free(dmah, DRM_MEM_DMA);
  98                 return NULL;
  99         }
 100
 101         ret = bus_dmamap_load(dmah->tag, dmah->map, dmah->vaddr, size,
 102             drm_pci_busdma_callback, dmah, BUS_DMA_NOWAIT);
 103         if (ret != 0) {
 104                 bus_dmamem_free(dmah->tag, dmah->vaddr, dmah->map);
 105                 bus_dma_tag_destroy(dmah->tag);
 106                 free(dmah, DRM_MEM_DMA);
 107                 return NULL;
 108         }
 109
 110         return dmah;
 111 }
 112
 113 /**
 114  * \brief Free a DMA-accessible consistent memory block.
 115  */
 116 void
 117 drm_pci_free(struct drm_device *dev, drm_dma_handle_t *dmah)
 118 {
 119         if (dmah == NULL)
 120                 return;
 121
 122         bus_dmamem_free(dmah->tag, dmah->vaddr, dmah->map);
 123         bus_dma_tag_destroy(dmah->tag);
 124
 125         free(dmah, DRM_MEM_DMA);
 126 }
 127
 128 /*@}*/