Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6.git] / drivers / gpu / drm / vmwgfx / vmwgfx_gmr.c
1 /**************************************************************************
2  *
3  * Copyright © 2009 VMware, Inc., Palo Alto, CA., USA
4  * All Rights Reserved.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sub license, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
25  *
26  **************************************************************************/
27
28 #include "vmwgfx_drv.h"
29 #include "drmP.h"
30 #include "ttm/ttm_bo_driver.h"
31
32 /**
33  * FIXME: Adjust to the ttm lowmem / highmem storage to minimize
34  * the number of used descriptors.
35  */
36
37 static int vmw_gmr_build_descriptors(struct list_head *desc_pages,
38                                      struct page *pages[],
39                                      unsigned long num_pages)
40 {
41         struct page *page, *next;
42         struct svga_guest_mem_descriptor *page_virtual = NULL;
43         struct svga_guest_mem_descriptor *desc_virtual = NULL;
44         unsigned int desc_per_page;
45         unsigned long prev_pfn;
46         unsigned long pfn;
47         int ret;
48
49         desc_per_page = PAGE_SIZE /
50             sizeof(struct svga_guest_mem_descriptor) - 1;
51
52         while (likely(num_pages != 0)) {
53                 page = alloc_page(__GFP_HIGHMEM);
54                 if (unlikely(page == NULL)) {
55                         ret = -ENOMEM;
56                         goto out_err;
57                 }
58
59                 list_add_tail(&page->lru, desc_pages);
60
61                 /*
62                  * Point previous page terminating descriptor to this
63                  * page before unmapping it.
64                  */
65
66                 if (likely(page_virtual != NULL)) {
67                         desc_virtual->ppn = page_to_pfn(page);
68                         kunmap_atomic(page_virtual, KM_USER0);
69                 }
70
71                 page_virtual = kmap_atomic(page, KM_USER0);
72                 desc_virtual = page_virtual - 1;
73                 prev_pfn = ~(0UL);
74
75                 while (likely(num_pages != 0)) {
76                         pfn = page_to_pfn(*pages);
77
78                         if (pfn != prev_pfn + 1) {
79
80                                 if (desc_virtual - page_virtual ==
81                                     desc_per_page - 1)
82                                         break;
83
84                                 (++desc_virtual)->ppn = cpu_to_le32(pfn);
85                                 desc_virtual->num_pages = cpu_to_le32(1);
86                         } else {
87                                 uint32_t tmp =
88                                     le32_to_cpu(desc_virtual->num_pages);
89                                 desc_virtual->num_pages = cpu_to_le32(tmp + 1);
90                         }
91                         prev_pfn = pfn;
92                         --num_pages;
93                         ++pages;
94                 }
95
96                 (++desc_virtual)->ppn = cpu_to_le32(0);
97                 desc_virtual->num_pages = cpu_to_le32(0);
98         }
99
100         if (likely(page_virtual != NULL))
101                 kunmap_atomic(page_virtual, KM_USER0);
102
103         return 0;
104 out_err:
105         list_for_each_entry_safe(page, next, desc_pages, lru) {
106                 list_del_init(&page->lru);
107                 __free_page(page);
108         }
109         return ret;
110 }
111
112 static inline void vmw_gmr_free_descriptors(struct list_head *desc_pages)
113 {
114         struct page *page, *next;
115
116         list_for_each_entry_safe(page, next, desc_pages, lru) {
117                 list_del_init(&page->lru);
118                 __free_page(page);
119         }
120 }
121
122 static void vmw_gmr_fire_descriptors(struct vmw_private *dev_priv,
123                                      int gmr_id, struct list_head *desc_pages)
124 {
125         struct page *page;
126
127         if (unlikely(list_empty(desc_pages)))
128                 return;
129
130         page = list_entry(desc_pages->next, struct page, lru);
131
132         mutex_lock(&dev_priv->hw_mutex);
133
134         vmw_write(dev_priv, SVGA_REG_GMR_ID, gmr_id);
135         wmb();
136         vmw_write(dev_priv, SVGA_REG_GMR_DESCRIPTOR, page_to_pfn(page));
137         mb();
138
139         mutex_unlock(&dev_priv->hw_mutex);
140
141 }
142
143 /**
144  * FIXME: Adjust to the ttm lowmem / highmem storage to minimize
145  * the number of used descriptors.
146  */
147
148 static unsigned long vmw_gmr_count_descriptors(struct page *pages[],
149                                                unsigned long num_pages)
150 {
151         unsigned long prev_pfn = ~(0UL);
152         unsigned long pfn;
153         unsigned long descriptors = 0;
154
155         while (num_pages--) {
156                 pfn = page_to_pfn(*pages++);
157                 if (prev_pfn + 1 != pfn)
158                         ++descriptors;
159                 prev_pfn = pfn;
160         }
161
162         return descriptors;
163 }
164
165 int vmw_gmr_bind(struct vmw_private *dev_priv,
166                  struct ttm_buffer_object *bo)
167 {
168         struct ttm_tt *ttm = bo->ttm;
169         unsigned long descriptors;
170         int ret;
171         uint32_t id;
172         struct list_head desc_pages;
173
174         if (!(dev_priv->capabilities & SVGA_CAP_GMR))
175                 return -EINVAL;
176
177         ret = ttm_tt_populate(ttm);
178         if (unlikely(ret != 0))
179                 return ret;
180
181         descriptors = vmw_gmr_count_descriptors(ttm->pages, ttm->num_pages);
182         if (unlikely(descriptors > dev_priv->max_gmr_descriptors))
183                 return -EINVAL;
184
185         INIT_LIST_HEAD(&desc_pages);
186         ret = vmw_gmr_build_descriptors(&desc_pages, ttm->pages,
187                                         ttm->num_pages);
188         if (unlikely(ret != 0))
189                 return ret;
190
191         ret = vmw_gmr_id_alloc(dev_priv, &id);
192         if (unlikely(ret != 0))
193                 goto out_no_id;
194
195         vmw_gmr_fire_descriptors(dev_priv, id, &desc_pages);
196         vmw_gmr_free_descriptors(&desc_pages);
197         vmw_dmabuf_set_gmr(bo, id);
198         return 0;
199
200 out_no_id:
201         vmw_gmr_free_descriptors(&desc_pages);
202         return ret;
203 }
204
205 void vmw_gmr_unbind(struct vmw_private *dev_priv, int gmr_id)
206 {
207         mutex_lock(&dev_priv->hw_mutex);
208         vmw_write(dev_priv, SVGA_REG_GMR_ID, gmr_id);
209         wmb();
210         vmw_write(dev_priv, SVGA_REG_GMR_DESCRIPTOR, 0);
211         mb();
212         mutex_unlock(&dev_priv->hw_mutex);
213 }