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
psb_gem_free_object(struct drm_gem_object * obj)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
psb_gem_get_aperture(struct drm_device * dev,void * data,struct drm_file * file)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 */
psb_gem_create(struct drm_file * file,struct drm_device * dev,u64 size,u32 * handlep,int stolen,u32 align)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_put_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 */
psb_gem_dumb_create(struct drm_file * file,struct drm_device * dev,struct drm_mode_create_dumb * args)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 */
psb_gem_fault(struct vm_fault * vmf)137 vm_fault_t 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 err;
143 vm_fault_t ret;
144 unsigned long pfn;
145 pgoff_t page_offset;
146 struct drm_device *dev;
147 struct drm_psb_private *dev_priv;
148
149 obj = vma->vm_private_data; /* GEM object */
150 dev = obj->dev;
151 dev_priv = dev->dev_private;
152
153 r = container_of(obj, struct gtt_range, gem); /* Get the gtt range */
154
155 /* Make sure we don't parallel update on a fault, nor move or remove
156 something from beneath our feet */
157 mutex_lock(&dev_priv->mmap_mutex);
158
159 /* For now the mmap pins the object and it stays pinned. As things
160 stand that will do us no harm */
161 if (r->mmapping == 0) {
162 err = psb_gtt_pin(r);
163 if (err < 0) {
164 dev_err(dev->dev, "gma500: pin failed: %d\n", err);
165 ret = vmf_error(err);
166 goto fail;
167 }
168 r->mmapping = 1;
169 }
170
171 /* Page relative to the VMA start - we must calculate this ourselves
172 because vmf->pgoff is the fake GEM offset */
173 page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
174
175 /* CPU view of the page, don't go via the GART for CPU writes */
176 if (r->stolen)
177 pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT;
178 else
179 pfn = page_to_pfn(r->pages[page_offset]);
180 ret = vmf_insert_pfn(vma, vmf->address, pfn);
181 fail:
182 mutex_unlock(&dev_priv->mmap_mutex);
183
184 return ret;
185 }
186
