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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 "psb_drv.h"
30 
psb_gem_init_object(struct drm_gem_object * obj)31 int psb_gem_init_object(struct drm_gem_object *obj)
32 {
33 	return -EINVAL;
34 }
35 
psb_gem_free_object(struct drm_gem_object * obj)36 void psb_gem_free_object(struct drm_gem_object *obj)
37 {
38 	struct gtt_range *gtt = container_of(obj, struct gtt_range, gem);
39 
40 	/* Remove the list map if one is present */
41 	if (obj->map_list.map)
42 		drm_gem_free_mmap_offset(obj);
43 	drm_gem_object_release(obj);
44 
45 	/* This must occur last as it frees up the memory of the GEM object */
46 	psb_gtt_free_range(obj->dev, gtt);
47 }
48 
psb_gem_get_aperture(struct drm_device * dev,void * data,struct drm_file * file)49 int psb_gem_get_aperture(struct drm_device *dev, void *data,
50 				struct drm_file *file)
51 {
52 	return -EINVAL;
53 }
54 
55 /**
56  *	psb_gem_dumb_map_gtt	-	buffer mapping for dumb interface
57  *	@file: our drm client file
58  *	@dev: drm device
59  *	@handle: GEM handle to the object (from dumb_create)
60  *
61  *	Do the necessary setup to allow the mapping of the frame buffer
62  *	into user memory. We don't have to do much here at the moment.
63  */
psb_gem_dumb_map_gtt(struct drm_file * file,struct drm_device * dev,uint32_t handle,uint64_t * offset)64 int psb_gem_dumb_map_gtt(struct drm_file *file, struct drm_device *dev,
65 			 uint32_t handle, uint64_t *offset)
66 {
67 	int ret = 0;
68 	struct drm_gem_object *obj;
69 
70 	if (!(dev->driver->driver_features & DRIVER_GEM))
71 		return -ENODEV;
72 
73 	mutex_lock(&dev->struct_mutex);
74 
75 	/* GEM does all our handle to object mapping */
76 	obj = drm_gem_object_lookup(dev, file, handle);
77 	if (obj == NULL) {
78 		ret = -ENOENT;
79 		goto unlock;
80 	}
81 	/* What validation is needed here ? */
82 
83 	/* Make it mmapable */
84 	if (!obj->map_list.map) {
85 		ret = drm_gem_create_mmap_offset(obj);
86 		if (ret)
87 			goto out;
88 	}
89 	/* GEM should really work out the hash offsets for us */
90 	*offset = (u64)obj->map_list.hash.key << PAGE_SHIFT;
91 out:
92 	drm_gem_object_unreference(obj);
93 unlock:
94 	mutex_unlock(&dev->struct_mutex);
95 	return ret;
96 }
97 
98 /**
99  *	psb_gem_create		-	create a mappable object
100  *	@file: the DRM file of the client
101  *	@dev: our device
102  *	@size: the size requested
103  *	@handlep: returned handle (opaque number)
104  *
105  *	Create a GEM object, fill in the boilerplate and attach a handle to
106  *	it so that userspace can speak about it. This does the core work
107  *	for the various methods that do/will create GEM objects for things
108  */
psb_gem_create(struct drm_file * file,struct drm_device * dev,uint64_t size,uint32_t * handlep)109 static int psb_gem_create(struct drm_file *file,
110 	struct drm_device *dev, uint64_t size, uint32_t *handlep)
111 {
112 	struct gtt_range *r;
113 	int ret;
114 	u32 handle;
115 
116 	size = roundup(size, PAGE_SIZE);
117 
118 	/* Allocate our object - for now a direct gtt range which is not
119 	   stolen memory backed */
120 	r = psb_gtt_alloc_range(dev, size, "gem", 0);
121 	if (r == NULL) {
122 		dev_err(dev->dev, "no memory for %lld byte GEM object\n", size);
123 		return -ENOSPC;
124 	}
125 	/* Initialize the extra goodies GEM needs to do all the hard work */
126 	if (drm_gem_object_init(dev, &r->gem, size) != 0) {
127 		psb_gtt_free_range(dev, r);
128 		/* GEM doesn't give an error code so use -ENOMEM */
129 		dev_err(dev->dev, "GEM init failed for %lld\n", size);
130 		return -ENOMEM;
131 	}
132 	/* Limit the object to 32bit mappings */
133 	mapping_set_gfp_mask(r->gem.filp->f_mapping, GFP_KERNEL | __GFP_DMA32);
134 	/* Give the object a handle so we can carry it more easily */
135 	ret = drm_gem_handle_create(file, &r->gem, &handle);
136 	if (ret) {
137 		dev_err(dev->dev, "GEM handle failed for %p, %lld\n",
138 							&r->gem, size);
139 		drm_gem_object_release(&r->gem);
140 		psb_gtt_free_range(dev, r);
141 		return ret;
142 	}
143 	/* We have the initial and handle reference but need only one now */
144 	drm_gem_object_unreference(&r->gem);
145 	*handlep = handle;
146 	return 0;
147 }
148 
149 /**
150  *	psb_gem_dumb_create	-	create a dumb buffer
151  *	@drm_file: our client file
152  *	@dev: our device
153  *	@args: the requested arguments copied from userspace
154  *
155  *	Allocate a buffer suitable for use for a frame buffer of the
156  *	form described by user space. Give userspace a handle by which
157  *	to reference it.
158  */
psb_gem_dumb_create(struct drm_file * file,struct drm_device * dev,struct drm_mode_create_dumb * args)159 int psb_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
160 			struct drm_mode_create_dumb *args)
161 {
162 	args->pitch = ALIGN(args->width * ((args->bpp + 7) / 8), 64);
163 	args->size = args->pitch * args->height;
164 	return psb_gem_create(file, dev, args->size, &args->handle);
165 }
166 
167 /**
168  *	psb_gem_dumb_destroy	-	destroy a dumb buffer
169  *	@file: client file
170  *	@dev: our DRM device
171  *	@handle: the object handle
172  *
173  *	Destroy a handle that was created via psb_gem_dumb_create, at least
174  *	we hope it was created that way. i915 seems to assume the caller
175  *	does the checking but that might be worth review ! FIXME
176  */
psb_gem_dumb_destroy(struct drm_file * file,struct drm_device * dev,uint32_t handle)177 int psb_gem_dumb_destroy(struct drm_file *file, struct drm_device *dev,
178 			uint32_t handle)
179 {
180 	/* No special work needed, drop the reference and see what falls out */
181 	return drm_gem_handle_delete(file, handle);
182 }
183 
184 /**
185  *	psb_gem_fault		-	pagefault handler for GEM objects
186  *	@vma: the VMA of the GEM object
187  *	@vmf: fault detail
188  *
189  *	Invoked when a fault occurs on an mmap of a GEM managed area. GEM
190  *	does most of the work for us including the actual map/unmap calls
191  *	but we need to do the actual page work.
192  *
193  *	This code eventually needs to handle faulting objects in and out
194  *	of the GTT and repacking it when we run out of space. We can put
195  *	that off for now and for our simple uses
196  *
197  *	The VMA was set up by GEM. In doing so it also ensured that the
198  *	vma->vm_private_data points to the GEM object that is backing this
199  *	mapping.
200  */
psb_gem_fault(struct vm_area_struct * vma,struct vm_fault * vmf)201 int psb_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
202 {
203 	struct drm_gem_object *obj;
204 	struct gtt_range *r;
205 	int ret;
206 	unsigned long pfn;
207 	pgoff_t page_offset;
208 	struct drm_device *dev;
209 	struct drm_psb_private *dev_priv;
210 
211 	obj = vma->vm_private_data;	/* GEM object */
212 	dev = obj->dev;
213 	dev_priv = dev->dev_private;
214 
215 	r = container_of(obj, struct gtt_range, gem);	/* Get the gtt range */
216 
217 	/* Make sure we don't parallel update on a fault, nor move or remove
218 	   something from beneath our feet */
219 	mutex_lock(&dev->struct_mutex);
220 
221 	/* For now the mmap pins the object and it stays pinned. As things
222 	   stand that will do us no harm */
223 	if (r->mmapping == 0) {
224 		ret = psb_gtt_pin(r);
225 		if (ret < 0) {
226 			dev_err(dev->dev, "gma500: pin failed: %d\n", ret);
227 			goto fail;
228 		}
229 		r->mmapping = 1;
230 	}
231 
232 	/* Page relative to the VMA start - we must calculate this ourselves
233 	   because vmf->pgoff is the fake GEM offset */
234 	page_offset = ((unsigned long) vmf->virtual_address - vma->vm_start)
235 				>> PAGE_SHIFT;
236 
237 	/* CPU view of the page, don't go via the GART for CPU writes */
238 	if (r->stolen)
239 		pfn = (dev_priv->stolen_base + r->offset) >> PAGE_SHIFT;
240 	else
241 		pfn = page_to_pfn(r->pages[page_offset]);
242 	ret = vm_insert_pfn(vma, (unsigned long)vmf->virtual_address, pfn);
243 
244 fail:
245 	mutex_unlock(&dev->struct_mutex);
246 	switch (ret) {
247 	case 0:
248 	case -ERESTARTSYS:
249 	case -EINTR:
250 		return VM_FAULT_NOPAGE;
251 	case -ENOMEM:
252 		return VM_FAULT_OOM;
253 	default:
254 		return VM_FAULT_SIGBUS;
255 	}
256 }
257 
psb_gem_create_stolen(struct drm_file * file,struct drm_device * dev,int size,u32 * handle)258 static int psb_gem_create_stolen(struct drm_file *file, struct drm_device *dev,
259 						int size, u32 *handle)
260 {
261 	struct gtt_range *gtt = psb_gtt_alloc_range(dev, size, "gem", 1);
262 	if (gtt == NULL)
263 		return -ENOMEM;
264 	if (drm_gem_private_object_init(dev, &gtt->gem, size) != 0)
265 		goto free_gtt;
266 	if (drm_gem_handle_create(file, &gtt->gem, handle) == 0)
267 		return 0;
268 free_gtt:
269 	psb_gtt_free_range(dev, gtt);
270 	return -ENOMEM;
271 }
272 
273 /*
274  *	GEM interfaces for our specific client
275  */
psb_gem_create_ioctl(struct drm_device * dev,void * data,struct drm_file * file)276 int psb_gem_create_ioctl(struct drm_device *dev, void *data,
277 					struct drm_file *file)
278 {
279 	struct drm_psb_gem_create *args = data;
280 	int ret;
281 	if (args->flags & GMA_GEM_CREATE_STOLEN) {
282 		ret = psb_gem_create_stolen(file, dev, args->size,
283 							&args->handle);
284 		if (ret == 0)
285 			return 0;
286 		/* Fall throguh */
287 		args->flags &= ~GMA_GEM_CREATE_STOLEN;
288 	}
289 	return psb_gem_create(file, dev, args->size, &args->handle);
290 }
291 
psb_gem_mmap_ioctl(struct drm_device * dev,void * data,struct drm_file * file)292 int psb_gem_mmap_ioctl(struct drm_device *dev, void *data,
293 					struct drm_file *file)
294 {
295 	struct drm_psb_gem_mmap *args = data;
296 	return dev->driver->dumb_map_offset(file, dev,
297 						args->handle, &args->offset);
298 }
299 
300