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 <drm/drmP.h> 15 #include <drm/drm.h> 16 #include <drm/gma_drm.h> 17 #include <drm/drm_vma_manager.h> 18 #include "psb_drv.h" 19 20 void psb_gem_free_object(struct drm_gem_object *obj) 21 { 22 struct gtt_range *gtt = container_of(obj, struct gtt_range, gem); 23 24 /* Remove the list map if one is present */ 25 drm_gem_free_mmap_offset(obj); 26 drm_gem_object_release(obj); 27 28 /* This must occur last as it frees up the memory of the GEM object */ 29 psb_gtt_free_range(obj->dev, gtt); 30 } 31 32 int psb_gem_get_aperture(struct drm_device *dev, void *data, 33 struct drm_file *file) 34 { 35 return -EINVAL; 36 } 37 38 /** 39 * psb_gem_create - create a mappable object 40 * @file: the DRM file of the client 41 * @dev: our device 42 * @size: the size requested 43 * @handlep: returned handle (opaque number) 44 * 45 * Create a GEM object, fill in the boilerplate and attach a handle to 46 * it so that userspace can speak about it. This does the core work 47 * for the various methods that do/will create GEM objects for things 48 */ 49 int psb_gem_create(struct drm_file *file, struct drm_device *dev, u64 size, 50 u32 *handlep, int stolen, u32 align) 51 { 52 struct gtt_range *r; 53 int ret; 54 u32 handle; 55 56 size = roundup(size, PAGE_SIZE); 57 58 /* Allocate our object - for now a direct gtt range which is not 59 stolen memory backed */ 60 r = psb_gtt_alloc_range(dev, size, "gem", 0, PAGE_SIZE); 61 if (r == NULL) { 62 dev_err(dev->dev, "no memory for %lld byte GEM object\n", size); 63 return -ENOSPC; 64 } 65 /* Initialize the extra goodies GEM needs to do all the hard work */ 66 if (drm_gem_object_init(dev, &r->gem, size) != 0) { 67 psb_gtt_free_range(dev, r); 68 /* GEM doesn't give an error code so use -ENOMEM */ 69 dev_err(dev->dev, "GEM init failed for %lld\n", size); 70 return -ENOMEM; 71 } 72 /* Limit the object to 32bit mappings */ 73 mapping_set_gfp_mask(r->gem.filp->f_mapping, GFP_KERNEL | __GFP_DMA32); 74 /* Give the object a handle so we can carry it more easily */ 75 ret = drm_gem_handle_create(file, &r->gem, &handle); 76 if (ret) { 77 dev_err(dev->dev, "GEM handle failed for %p, %lld\n", 78 &r->gem, size); 79 drm_gem_object_release(&r->gem); 80 psb_gtt_free_range(dev, r); 81 return ret; 82 } 83 /* We have the initial and handle reference but need only one now */ 84 drm_gem_object_put_unlocked(&r->gem); 85 *handlep = handle; 86 return 0; 87 } 88 89 /** 90 * psb_gem_dumb_create - create a dumb buffer 91 * @drm_file: our client file 92 * @dev: our device 93 * @args: the requested arguments copied from userspace 94 * 95 * Allocate a buffer suitable for use for a frame buffer of the 96 * form described by user space. Give userspace a handle by which 97 * to reference it. 98 */ 99 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev, 100 struct drm_mode_create_dumb *args) 101 { 102 args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64); 103 args->size = args->pitch * args->height; 104 return psb_gem_create(file, dev, args->size, &args->handle, 0, 105 PAGE_SIZE); 106 } 107 108 /** 109 * psb_gem_fault - pagefault handler for GEM objects 110 * @vma: the VMA of the GEM object 111 * @vmf: fault detail 112 * 113 * Invoked when a fault occurs on an mmap of a GEM managed area. GEM 114 * does most of the work for us including the actual map/unmap calls 115 * but we need to do the actual page work. 116 * 117 * This code eventually needs to handle faulting objects in and out 118 * of the GTT and repacking it when we run out of space. We can put 119 * that off for now and for our simple uses 120 * 121 * The VMA was set up by GEM. In doing so it also ensured that the 122 * vma->vm_private_data points to the GEM object that is backing this 123 * mapping. 124 */ 125 vm_fault_t psb_gem_fault(struct vm_fault *vmf) 126 { 127 struct vm_area_struct *vma = vmf->vma; 128 struct drm_gem_object *obj; 129 struct gtt_range *r; 130 int err; 131 vm_fault_t ret; 132 unsigned long pfn; 133 pgoff_t page_offset; 134 struct drm_device *dev; 135 struct drm_psb_private *dev_priv; 136 137 obj = vma->vm_private_data; /* GEM object */ 138 dev = obj->dev; 139 dev_priv = dev->dev_private; 140 141 r = container_of(obj, struct gtt_range, gem); /* Get the gtt range */ 142 143 /* Make sure we don't parallel update on a fault, nor move or remove 144 something from beneath our feet */ 145 mutex_lock(&dev_priv->mmap_mutex); 146 147 /* For now the mmap pins the object and it stays pinned. As things 148 stand that will do us no harm */ 149 if (r->mmapping == 0) { 150 err = psb_gtt_pin(r); 151 if (err < 0) { 152 dev_err(dev->dev, "gma500: pin failed: %d\n", err); 153 ret = vmf_error(err); 154 goto fail; 155 } 156 r->mmapping = 1; 157 } 158 159 /* Page relative to the VMA start - we must calculate this ourselves 160 because vmf->pgoff is the fake GEM offset */ 161 page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT; 162 163 /* CPU view of the page, don't go via the GART for CPU writes */ 164 if (r->stolen) 165 pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT; 166 else 167 pfn = page_to_pfn(r->pages[page_offset]); 168 ret = vmf_insert_pfn(vma, vmf->address, pfn); 169 fail: 170 mutex_unlock(&dev_priv->mmap_mutex); 171 172 return ret; 173 } 174