1 /* 2 * psb GEM interface 3 * 4 * Copyright (c) 2011, Intel Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 * You should have received a copy of the GNU General Public License along with 16 * this program; if not, write to the Free Software Foundation, Inc., 17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Authors: Alan Cox 20 * 21 * TODO: 22 * - we need to work out if the MMU is relevant (eg for 23 * accelerated operations on a GEM object) 24 */ 25 26 #include <drm/drmP.h> 27 #include <drm/drm.h> 28 #include <drm/gma_drm.h> 29 #include <drm/drm_vma_manager.h> 30 #include "psb_drv.h" 31 32 void psb_gem_free_object(struct drm_gem_object *obj) 33 { 34 struct gtt_range *gtt = container_of(obj, struct gtt_range, gem); 35 36 /* Remove the list map if one is present */ 37 drm_gem_free_mmap_offset(obj); 38 drm_gem_object_release(obj); 39 40 /* This must occur last as it frees up the memory of the GEM object */ 41 psb_gtt_free_range(obj->dev, gtt); 42 } 43 44 int psb_gem_get_aperture(struct drm_device *dev, void *data, 45 struct drm_file *file) 46 { 47 return -EINVAL; 48 } 49 50 /** 51 * psb_gem_dumb_map_gtt - buffer mapping for dumb interface 52 * @file: our drm client file 53 * @dev: drm device 54 * @handle: GEM handle to the object (from dumb_create) 55 * 56 * Do the necessary setup to allow the mapping of the frame buffer 57 * into user memory. We don't have to do much here at the moment. 58 */ 59 int psb_gem_dumb_map_gtt(struct drm_file *file, struct drm_device *dev, 60 uint32_t handle, uint64_t *offset) 61 { 62 int ret = 0; 63 struct drm_gem_object *obj; 64 65 /* GEM does all our handle to object mapping */ 66 obj = drm_gem_object_lookup(file, handle); 67 if (obj == NULL) 68 return -ENOENT; 69 70 /* Make it mmapable */ 71 ret = drm_gem_create_mmap_offset(obj); 72 if (ret) 73 goto out; 74 *offset = drm_vma_node_offset_addr(&obj->vma_node); 75 out: 76 drm_gem_object_unreference_unlocked(obj); 77 return ret; 78 } 79 80 /** 81 * psb_gem_create - create a mappable object 82 * @file: the DRM file of the client 83 * @dev: our device 84 * @size: the size requested 85 * @handlep: returned handle (opaque number) 86 * 87 * Create a GEM object, fill in the boilerplate and attach a handle to 88 * it so that userspace can speak about it. This does the core work 89 * for the various methods that do/will create GEM objects for things 90 */ 91 int psb_gem_create(struct drm_file *file, struct drm_device *dev, u64 size, 92 u32 *handlep, int stolen, u32 align) 93 { 94 struct gtt_range *r; 95 int ret; 96 u32 handle; 97 98 size = roundup(size, PAGE_SIZE); 99 100 /* Allocate our object - for now a direct gtt range which is not 101 stolen memory backed */ 102 r = psb_gtt_alloc_range(dev, size, "gem", 0, PAGE_SIZE); 103 if (r == NULL) { 104 dev_err(dev->dev, "no memory for %lld byte GEM object\n", size); 105 return -ENOSPC; 106 } 107 /* Initialize the extra goodies GEM needs to do all the hard work */ 108 if (drm_gem_object_init(dev, &r->gem, size) != 0) { 109 psb_gtt_free_range(dev, r); 110 /* GEM doesn't give an error code so use -ENOMEM */ 111 dev_err(dev->dev, "GEM init failed for %lld\n", size); 112 return -ENOMEM; 113 } 114 /* Limit the object to 32bit mappings */ 115 mapping_set_gfp_mask(r->gem.filp->f_mapping, GFP_KERNEL | __GFP_DMA32); 116 /* Give the object a handle so we can carry it more easily */ 117 ret = drm_gem_handle_create(file, &r->gem, &handle); 118 if (ret) { 119 dev_err(dev->dev, "GEM handle failed for %p, %lld\n", 120 &r->gem, size); 121 drm_gem_object_release(&r->gem); 122 psb_gtt_free_range(dev, r); 123 return ret; 124 } 125 /* We have the initial and handle reference but need only one now */ 126 drm_gem_object_unreference_unlocked(&r->gem); 127 *handlep = handle; 128 return 0; 129 } 130 131 /** 132 * psb_gem_dumb_create - create a dumb buffer 133 * @drm_file: our client file 134 * @dev: our device 135 * @args: the requested arguments copied from userspace 136 * 137 * Allocate a buffer suitable for use for a frame buffer of the 138 * form described by user space. Give userspace a handle by which 139 * to reference it. 140 */ 141 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev, 142 struct drm_mode_create_dumb *args) 143 { 144 args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64); 145 args->size = args->pitch * args->height; 146 return psb_gem_create(file, dev, args->size, &args->handle, 0, 147 PAGE_SIZE); 148 } 149 150 /** 151 * psb_gem_fault - pagefault handler for GEM objects 152 * @vma: the VMA of the GEM object 153 * @vmf: fault detail 154 * 155 * Invoked when a fault occurs on an mmap of a GEM managed area. GEM 156 * does most of the work for us including the actual map/unmap calls 157 * but we need to do the actual page work. 158 * 159 * This code eventually needs to handle faulting objects in and out 160 * of the GTT and repacking it when we run out of space. We can put 161 * that off for now and for our simple uses 162 * 163 * The VMA was set up by GEM. In doing so it also ensured that the 164 * vma->vm_private_data points to the GEM object that is backing this 165 * mapping. 166 */ 167 int psb_gem_fault(struct vm_fault *vmf) 168 { 169 struct vm_area_struct *vma = vmf->vma; 170 struct drm_gem_object *obj; 171 struct gtt_range *r; 172 int ret; 173 unsigned long pfn; 174 pgoff_t page_offset; 175 struct drm_device *dev; 176 struct drm_psb_private *dev_priv; 177 178 obj = vma->vm_private_data; /* GEM object */ 179 dev = obj->dev; 180 dev_priv = dev->dev_private; 181 182 r = container_of(obj, struct gtt_range, gem); /* Get the gtt range */ 183 184 /* Make sure we don't parallel update on a fault, nor move or remove 185 something from beneath our feet */ 186 mutex_lock(&dev_priv->mmap_mutex); 187 188 /* For now the mmap pins the object and it stays pinned. As things 189 stand that will do us no harm */ 190 if (r->mmapping == 0) { 191 ret = psb_gtt_pin(r); 192 if (ret < 0) { 193 dev_err(dev->dev, "gma500: pin failed: %d\n", ret); 194 goto fail; 195 } 196 r->mmapping = 1; 197 } 198 199 /* Page relative to the VMA start - we must calculate this ourselves 200 because vmf->pgoff is the fake GEM offset */ 201 page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT; 202 203 /* CPU view of the page, don't go via the GART for CPU writes */ 204 if (r->stolen) 205 pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT; 206 else 207 pfn = page_to_pfn(r->pages[page_offset]); 208 ret = vm_insert_pfn(vma, vmf->address, pfn); 209 210 fail: 211 mutex_unlock(&dev_priv->mmap_mutex); 212 switch (ret) { 213 case 0: 214 case -ERESTARTSYS: 215 case -EINTR: 216 return VM_FAULT_NOPAGE; 217 case -ENOMEM: 218 return VM_FAULT_OOM; 219 default: 220 return VM_FAULT_SIGBUS; 221 } 222 } 223