1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * psb GEM interface 4 * 5 * Copyright (c) 2011, Intel Corporation. 6 * 7 * Authors: Alan Cox 8 * 9 * TODO: 10 * - we need to work out if the MMU is relevant (eg for 11 * accelerated operations on a GEM object) 12 */ 13 14 #include <linux/pagemap.h> 15 16 #include <asm/set_memory.h> 17 18 #include <drm/drm.h> 19 #include <drm/drm_vma_manager.h> 20 21 #include "gem.h" 22 #include "psb_drv.h" 23 24 int psb_gem_pin(struct psb_gem_object *pobj) 25 { 26 struct drm_gem_object *obj = &pobj->base; 27 struct drm_device *dev = obj->dev; 28 struct drm_psb_private *dev_priv = to_drm_psb_private(dev); 29 u32 gpu_base = dev_priv->gtt.gatt_start; 30 struct page **pages; 31 unsigned int npages; 32 int ret; 33 34 mutex_lock(&dev_priv->gtt_mutex); 35 36 if (pobj->in_gart || pobj->stolen) 37 goto out; /* already mapped */ 38 39 pages = drm_gem_get_pages(obj); 40 if (IS_ERR(pages)) { 41 ret = PTR_ERR(pages); 42 goto err_mutex_unlock; 43 } 44 45 npages = obj->size / PAGE_SIZE; 46 47 set_pages_array_wc(pages, npages); 48 49 psb_gtt_insert_pages(dev_priv, &pobj->resource, pages); 50 psb_mmu_insert_pages(psb_mmu_get_default_pd(dev_priv->mmu), pages, 51 (gpu_base + pobj->offset), npages, 0, 0, 52 PSB_MMU_CACHED_MEMORY); 53 54 pobj->npage = npages; 55 pobj->pages = pages; 56 57 out: 58 ++pobj->in_gart; 59 mutex_unlock(&dev_priv->gtt_mutex); 60 61 return 0; 62 63 err_mutex_unlock: 64 mutex_unlock(&dev_priv->gtt_mutex); 65 return ret; 66 } 67 68 void psb_gem_unpin(struct psb_gem_object *pobj) 69 { 70 struct drm_gem_object *obj = &pobj->base; 71 struct drm_device *dev = obj->dev; 72 struct drm_psb_private *dev_priv = to_drm_psb_private(dev); 73 u32 gpu_base = dev_priv->gtt.gatt_start; 74 75 mutex_lock(&dev_priv->gtt_mutex); 76 77 WARN_ON(!pobj->in_gart); 78 79 --pobj->in_gart; 80 81 if (pobj->in_gart || pobj->stolen) 82 goto out; 83 84 psb_mmu_remove_pages(psb_mmu_get_default_pd(dev_priv->mmu), 85 (gpu_base + pobj->offset), pobj->npage, 0, 0); 86 psb_gtt_remove_pages(dev_priv, &pobj->resource); 87 88 /* Reset caching flags */ 89 set_pages_array_wb(pobj->pages, pobj->npage); 90 91 drm_gem_put_pages(obj, pobj->pages, true, false); 92 pobj->pages = NULL; 93 pobj->npage = 0; 94 95 out: 96 mutex_unlock(&dev_priv->gtt_mutex); 97 } 98 99 static vm_fault_t psb_gem_fault(struct vm_fault *vmf); 100 101 static void psb_gem_free_object(struct drm_gem_object *obj) 102 { 103 struct psb_gem_object *pobj = to_psb_gem_object(obj); 104 105 drm_gem_object_release(obj); 106 107 /* Undo the mmap pin if we are destroying the object */ 108 if (pobj->mmapping) 109 psb_gem_unpin(pobj); 110 111 WARN_ON(pobj->in_gart && !pobj->stolen); 112 113 release_resource(&pobj->resource); 114 kfree(pobj); 115 } 116 117 static const struct vm_operations_struct psb_gem_vm_ops = { 118 .fault = psb_gem_fault, 119 .open = drm_gem_vm_open, 120 .close = drm_gem_vm_close, 121 }; 122 123 static const struct drm_gem_object_funcs psb_gem_object_funcs = { 124 .free = psb_gem_free_object, 125 .vm_ops = &psb_gem_vm_ops, 126 }; 127 128 struct psb_gem_object * 129 psb_gem_create(struct drm_device *dev, u64 size, const char *name, bool stolen, u32 align) 130 { 131 struct drm_psb_private *dev_priv = to_drm_psb_private(dev); 132 struct psb_gem_object *pobj; 133 struct drm_gem_object *obj; 134 int ret; 135 136 size = roundup(size, PAGE_SIZE); 137 138 pobj = kzalloc(sizeof(*pobj), GFP_KERNEL); 139 if (!pobj) 140 return ERR_PTR(-ENOMEM); 141 obj = &pobj->base; 142 143 /* GTT resource */ 144 145 ret = psb_gtt_allocate_resource(dev_priv, &pobj->resource, name, size, align, stolen, 146 &pobj->offset); 147 if (ret) 148 goto err_kfree; 149 150 if (stolen) { 151 pobj->stolen = true; 152 pobj->in_gart = 1; 153 } 154 155 /* GEM object */ 156 157 obj->funcs = &psb_gem_object_funcs; 158 159 if (stolen) { 160 drm_gem_private_object_init(dev, obj, size); 161 } else { 162 ret = drm_gem_object_init(dev, obj, size); 163 if (ret) 164 goto err_release_resource; 165 166 /* Limit the object to 32-bit mappings */ 167 mapping_set_gfp_mask(obj->filp->f_mapping, GFP_KERNEL | __GFP_DMA32); 168 } 169 170 return pobj; 171 172 err_release_resource: 173 release_resource(&pobj->resource); 174 err_kfree: 175 kfree(pobj); 176 return ERR_PTR(ret); 177 } 178 179 /** 180 * psb_gem_dumb_create - create a dumb buffer 181 * @file: our client file 182 * @dev: our device 183 * @args: the requested arguments copied from userspace 184 * 185 * Allocate a buffer suitable for use for a frame buffer of the 186 * form described by user space. Give userspace a handle by which 187 * to reference it. 188 */ 189 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev, 190 struct drm_mode_create_dumb *args) 191 { 192 size_t pitch, size; 193 struct psb_gem_object *pobj; 194 struct drm_gem_object *obj; 195 u32 handle; 196 int ret; 197 198 pitch = args->width * DIV_ROUND_UP(args->bpp, 8); 199 pitch = ALIGN(pitch, 64); 200 201 size = pitch * args->height; 202 size = roundup(size, PAGE_SIZE); 203 if (!size) 204 return -EINVAL; 205 206 pobj = psb_gem_create(dev, size, "gem", false, PAGE_SIZE); 207 if (IS_ERR(pobj)) 208 return PTR_ERR(pobj); 209 obj = &pobj->base; 210 211 ret = drm_gem_handle_create(file, obj, &handle); 212 if (ret) 213 goto err_drm_gem_object_put; 214 215 drm_gem_object_put(obj); 216 217 args->pitch = pitch; 218 args->size = size; 219 args->handle = handle; 220 221 return 0; 222 223 err_drm_gem_object_put: 224 drm_gem_object_put(obj); 225 return ret; 226 } 227 228 /** 229 * psb_gem_fault - pagefault handler for GEM objects 230 * @vmf: fault detail 231 * 232 * Invoked when a fault occurs on an mmap of a GEM managed area. GEM 233 * does most of the work for us including the actual map/unmap calls 234 * but we need to do the actual page work. 235 * 236 * This code eventually needs to handle faulting objects in and out 237 * of the GTT and repacking it when we run out of space. We can put 238 * that off for now and for our simple uses 239 * 240 * The VMA was set up by GEM. In doing so it also ensured that the 241 * vma->vm_private_data points to the GEM object that is backing this 242 * mapping. 243 */ 244 static vm_fault_t psb_gem_fault(struct vm_fault *vmf) 245 { 246 struct vm_area_struct *vma = vmf->vma; 247 struct drm_gem_object *obj; 248 struct psb_gem_object *pobj; 249 int err; 250 vm_fault_t ret; 251 unsigned long pfn; 252 pgoff_t page_offset; 253 struct drm_device *dev; 254 struct drm_psb_private *dev_priv; 255 256 obj = vma->vm_private_data; /* GEM object */ 257 dev = obj->dev; 258 dev_priv = to_drm_psb_private(dev); 259 260 pobj = to_psb_gem_object(obj); 261 262 /* Make sure we don't parallel update on a fault, nor move or remove 263 something from beneath our feet */ 264 mutex_lock(&dev_priv->mmap_mutex); 265 266 /* For now the mmap pins the object and it stays pinned. As things 267 stand that will do us no harm */ 268 if (pobj->mmapping == 0) { 269 err = psb_gem_pin(pobj); 270 if (err < 0) { 271 dev_err(dev->dev, "gma500: pin failed: %d\n", err); 272 ret = vmf_error(err); 273 goto fail; 274 } 275 pobj->mmapping = 1; 276 } 277 278 /* Page relative to the VMA start - we must calculate this ourselves 279 because vmf->pgoff is the fake GEM offset */ 280 page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT; 281 282 /* CPU view of the page, don't go via the GART for CPU writes */ 283 if (pobj->stolen) 284 pfn = (dev_priv->stolen_base + pobj->offset) >> PAGE_SHIFT; 285 else 286 pfn = page_to_pfn(pobj->pages[page_offset]); 287 ret = vmf_insert_pfn(vma, vmf->address, pfn); 288 fail: 289 mutex_unlock(&dev_priv->mmap_mutex); 290 291 return ret; 292 } 293