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 <drm/drm.h> 17 #include <drm/drm_vma_manager.h> 18 19 #include "psb_drv.h" 20 21 void psb_gem_free_object(struct drm_gem_object *obj) 22 { 23 struct gtt_range *gtt = container_of(obj, struct gtt_range, gem); 24 25 /* Remove the list map if one is present */ 26 drm_gem_free_mmap_offset(obj); 27 drm_gem_object_release(obj); 28 29 /* This must occur last as it frees up the memory of the GEM object */ 30 psb_gtt_free_range(obj->dev, gtt); 31 } 32 33 int psb_gem_get_aperture(struct drm_device *dev, void *data, 34 struct drm_file *file) 35 { 36 return -EINVAL; 37 } 38 39 /** 40 * psb_gem_create - create a mappable object 41 * @file: the DRM file of the client 42 * @dev: our device 43 * @size: the size requested 44 * @handlep: returned handle (opaque number) 45 * 46 * Create a GEM object, fill in the boilerplate and attach a handle to 47 * it so that userspace can speak about it. This does the core work 48 * for the various methods that do/will create GEM objects for things 49 */ 50 int psb_gem_create(struct drm_file *file, struct drm_device *dev, u64 size, 51 u32 *handlep, int stolen, u32 align) 52 { 53 struct gtt_range *r; 54 int ret; 55 u32 handle; 56 57 size = roundup(size, PAGE_SIZE); 58 59 /* Allocate our object - for now a direct gtt range which is not 60 stolen memory backed */ 61 r = psb_gtt_alloc_range(dev, size, "gem", 0, PAGE_SIZE); 62 if (r == NULL) { 63 dev_err(dev->dev, "no memory for %lld byte GEM object\n", size); 64 return -ENOSPC; 65 } 66 /* Initialize the extra goodies GEM needs to do all the hard work */ 67 if (drm_gem_object_init(dev, &r->gem, size) != 0) { 68 psb_gtt_free_range(dev, r); 69 /* GEM doesn't give an error code so use -ENOMEM */ 70 dev_err(dev->dev, "GEM init failed for %lld\n", size); 71 return -ENOMEM; 72 } 73 /* Limit the object to 32bit mappings */ 74 mapping_set_gfp_mask(r->gem.filp->f_mapping, GFP_KERNEL | __GFP_DMA32); 75 /* Give the object a handle so we can carry it more easily */ 76 ret = drm_gem_handle_create(file, &r->gem, &handle); 77 if (ret) { 78 dev_err(dev->dev, "GEM handle failed for %p, %lld\n", 79 &r->gem, size); 80 drm_gem_object_release(&r->gem); 81 psb_gtt_free_range(dev, r); 82 return ret; 83 } 84 /* We have the initial and handle reference but need only one now */ 85 drm_gem_object_put(&r->gem); 86 *handlep = handle; 87 return 0; 88 } 89 90 /** 91 * psb_gem_dumb_create - create a dumb buffer 92 * @drm_file: our client file 93 * @dev: our device 94 * @args: the requested arguments copied from userspace 95 * 96 * Allocate a buffer suitable for use for a frame buffer of the 97 * form described by user space. Give userspace a handle by which 98 * to reference it. 99 */ 100 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev, 101 struct drm_mode_create_dumb *args) 102 { 103 args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64); 104 args->size = args->pitch * args->height; 105 return psb_gem_create(file, dev, args->size, &args->handle, 0, 106 PAGE_SIZE); 107 } 108 109 /** 110 * psb_gem_fault - pagefault handler for GEM objects 111 * @vma: the VMA of the GEM object 112 * @vmf: fault detail 113 * 114 * Invoked when a fault occurs on an mmap of a GEM managed area. GEM 115 * does most of the work for us including the actual map/unmap calls 116 * but we need to do the actual page work. 117 * 118 * This code eventually needs to handle faulting objects in and out 119 * of the GTT and repacking it when we run out of space. We can put 120 * that off for now and for our simple uses 121 * 122 * The VMA was set up by GEM. In doing so it also ensured that the 123 * vma->vm_private_data points to the GEM object that is backing this 124 * mapping. 125 */ 126 vm_fault_t psb_gem_fault(struct vm_fault *vmf) 127 { 128 struct vm_area_struct *vma = vmf->vma; 129 struct drm_gem_object *obj; 130 struct gtt_range *r; 131 int err; 132 vm_fault_t ret; 133 unsigned long pfn; 134 pgoff_t page_offset; 135 struct drm_device *dev; 136 struct drm_psb_private *dev_priv; 137 138 obj = vma->vm_private_data; /* GEM object */ 139 dev = obj->dev; 140 dev_priv = dev->dev_private; 141 142 r = container_of(obj, struct gtt_range, gem); /* Get the gtt range */ 143 144 /* Make sure we don't parallel update on a fault, nor move or remove 145 something from beneath our feet */ 146 mutex_lock(&dev_priv->mmap_mutex); 147 148 /* For now the mmap pins the object and it stays pinned. As things 149 stand that will do us no harm */ 150 if (r->mmapping == 0) { 151 err = psb_gtt_pin(r); 152 if (err < 0) { 153 dev_err(dev->dev, "gma500: pin failed: %d\n", err); 154 ret = vmf_error(err); 155 goto fail; 156 } 157 r->mmapping = 1; 158 } 159 160 /* Page relative to the VMA start - we must calculate this ourselves 161 because vmf->pgoff is the fake GEM offset */ 162 page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT; 163 164 /* CPU view of the page, don't go via the GART for CPU writes */ 165 if (r->stolen) 166 pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT; 167 else 168 pfn = page_to_pfn(r->pages[page_offset]); 169 ret = vmf_insert_pfn(vma, vmf->address, pfn); 170 fail: 171 mutex_unlock(&dev_priv->mmap_mutex); 172 173 return ret; 174 } 175