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 page *pages[],
167 		 unsigned long num_pages,
168 		 int gmr_id)
169 {
170 	struct list_head desc_pages;
171 	int ret;
172 
173 	if (unlikely(!(dev_priv->capabilities & SVGA_CAP_GMR)))
174 		return -EINVAL;
175 
176 	if (vmw_gmr_count_descriptors(pages, num_pages) >
177 	    dev_priv->max_gmr_descriptors)
178 		return -EINVAL;
179 
180 	INIT_LIST_HEAD(&desc_pages);
181 
182 	ret = vmw_gmr_build_descriptors(&desc_pages, pages, num_pages);
183 	if (unlikely(ret != 0))
184 		return ret;
185 
186 	vmw_gmr_fire_descriptors(dev_priv, gmr_id, &desc_pages);
187 	vmw_gmr_free_descriptors(&desc_pages);
188 
189 	return 0;
190 }
191 
192 
193 void vmw_gmr_unbind(struct vmw_private *dev_priv, int gmr_id)
194 {
195 	mutex_lock(&dev_priv->hw_mutex);
196 	vmw_write(dev_priv, SVGA_REG_GMR_ID, gmr_id);
197 	wmb();
198 	vmw_write(dev_priv, SVGA_REG_GMR_DESCRIPTOR, 0);
199 	mb();
200 	mutex_unlock(&dev_priv->hw_mutex);
201 }
202