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_create - create a mappable object 52 * @file: the DRM file of the client 53 * @dev: our device 54 * @size: the size requested 55 * @handlep: returned handle (opaque number) 56 * 57 * Create a GEM object, fill in the boilerplate and attach a handle to 58 * it so that userspace can speak about it. This does the core work 59 * for the various methods that do/will create GEM objects for things 60 */ 61 int psb_gem_create(struct drm_file *file, struct drm_device *dev, u64 size, 62 u32 *handlep, int stolen, u32 align) 63 { 64 struct gtt_range *r; 65 int ret; 66 u32 handle; 67 68 size = roundup(size, PAGE_SIZE); 69 70 /* Allocate our object - for now a direct gtt range which is not 71 stolen memory backed */ 72 r = psb_gtt_alloc_range(dev, size, "gem", 0, PAGE_SIZE); 73 if (r == NULL) { 74 dev_err(dev->dev, "no memory for %lld byte GEM object\n", size); 75 return -ENOSPC; 76 } 77 /* Initialize the extra goodies GEM needs to do all the hard work */ 78 if (drm_gem_object_init(dev, &r->gem, size) != 0) { 79 psb_gtt_free_range(dev, r); 80 /* GEM doesn't give an error code so use -ENOMEM */ 81 dev_err(dev->dev, "GEM init failed for %lld\n", size); 82 return -ENOMEM; 83 } 84 /* Limit the object to 32bit mappings */ 85 mapping_set_gfp_mask(r->gem.filp->f_mapping, GFP_KERNEL | __GFP_DMA32); 86 /* Give the object a handle so we can carry it more easily */ 87 ret = drm_gem_handle_create(file, &r->gem, &handle); 88 if (ret) { 89 dev_err(dev->dev, "GEM handle failed for %p, %lld\n", 90 &r->gem, size); 91 drm_gem_object_release(&r->gem); 92 psb_gtt_free_range(dev, r); 93 return ret; 94 } 95 /* We have the initial and handle reference but need only one now */ 96 drm_gem_object_unreference_unlocked(&r->gem); 97 *handlep = handle; 98 return 0; 99 } 100 101 /** 102 * psb_gem_dumb_create - create a dumb buffer 103 * @drm_file: our client file 104 * @dev: our device 105 * @args: the requested arguments copied from userspace 106 * 107 * Allocate a buffer suitable for use for a frame buffer of the 108 * form described by user space. Give userspace a handle by which 109 * to reference it. 110 */ 111 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev, 112 struct drm_mode_create_dumb *args) 113 { 114 args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64); 115 args->size = args->pitch * args->height; 116 return psb_gem_create(file, dev, args->size, &args->handle, 0, 117 PAGE_SIZE); 118 } 119 120 /** 121 * psb_gem_fault - pagefault handler for GEM objects 122 * @vma: the VMA of the GEM object 123 * @vmf: fault detail 124 * 125 * Invoked when a fault occurs on an mmap of a GEM managed area. GEM 126 * does most of the work for us including the actual map/unmap calls 127 * but we need to do the actual page work. 128 * 129 * This code eventually needs to handle faulting objects in and out 130 * of the GTT and repacking it when we run out of space. We can put 131 * that off for now and for our simple uses 132 * 133 * The VMA was set up by GEM. In doing so it also ensured that the 134 * vma->vm_private_data points to the GEM object that is backing this 135 * mapping. 136 */ 137 int psb_gem_fault(struct vm_fault *vmf) 138 { 139 struct vm_area_struct *vma = vmf->vma; 140 struct drm_gem_object *obj; 141 struct gtt_range *r; 142 int ret; 143 unsigned long pfn; 144 pgoff_t page_offset; 145 struct drm_device *dev; 146 struct drm_psb_private *dev_priv; 147 148 obj = vma->vm_private_data; /* GEM object */ 149 dev = obj->dev; 150 dev_priv = dev->dev_private; 151 152 r = container_of(obj, struct gtt_range, gem); /* Get the gtt range */ 153 154 /* Make sure we don't parallel update on a fault, nor move or remove 155 something from beneath our feet */ 156 mutex_lock(&dev_priv->mmap_mutex); 157 158 /* For now the mmap pins the object and it stays pinned. As things 159 stand that will do us no harm */ 160 if (r->mmapping == 0) { 161 ret = psb_gtt_pin(r); 162 if (ret < 0) { 163 dev_err(dev->dev, "gma500: pin failed: %d\n", ret); 164 goto fail; 165 } 166 r->mmapping = 1; 167 } 168 169 /* Page relative to the VMA start - we must calculate this ourselves 170 because vmf->pgoff is the fake GEM offset */ 171 page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT; 172 173 /* CPU view of the page, don't go via the GART for CPU writes */ 174 if (r->stolen) 175 pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT; 176 else 177 pfn = page_to_pfn(r->pages[page_offset]); 178 ret = vm_insert_pfn(vma, vmf->address, pfn); 179 180 fail: 181 mutex_unlock(&dev_priv->mmap_mutex); 182 switch (ret) { 183 case 0: 184 case -ERESTARTSYS: 185 case -EINTR: 186 return VM_FAULT_NOPAGE; 187 case -ENOMEM: 188 return VM_FAULT_OOM; 189 default: 190 return VM_FAULT_SIGBUS; 191 } 192 } 193