xref: /linux/drivers/gpu/drm/vmwgfx/vmwgfx_gmrid_manager.c (revision 765532c8aaac624b5f8687af6d319c6a1138a257)
1 /**************************************************************************
2  *
3  * Copyright (c) 2007-2010 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  * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
29  */
30 
31 #include "vmwgfx_drv.h"
32 #include "ttm/ttm_module.h"
33 #include "ttm/ttm_bo_driver.h"
34 #include "ttm/ttm_placement.h"
35 #include <linux/idr.h>
36 #include <linux/spinlock.h>
37 #include <linux/kernel.h>
38 
39 struct vmwgfx_gmrid_man {
40 	spinlock_t lock;
41 	struct ida gmr_ida;
42 	uint32_t max_gmr_ids;
43 };
44 
45 static int vmw_gmrid_man_get_node(struct ttm_mem_type_manager *man,
46 				  struct ttm_buffer_object *bo,
47 				  struct ttm_placement *placement,
48 				  struct ttm_mem_reg *mem)
49 {
50 	struct vmwgfx_gmrid_man *gman =
51 		(struct vmwgfx_gmrid_man *)man->priv;
52 	int ret;
53 	int id;
54 
55 	mem->mm_node = NULL;
56 
57 	do {
58 		if (unlikely(ida_pre_get(&gman->gmr_ida, GFP_KERNEL) == 0))
59 			return -ENOMEM;
60 
61 		spin_lock(&gman->lock);
62 		ret = ida_get_new(&gman->gmr_ida, &id);
63 
64 		if (unlikely(ret == 0 && id >= gman->max_gmr_ids)) {
65 			ida_remove(&gman->gmr_ida, id);
66 			spin_unlock(&gman->lock);
67 			return 0;
68 		}
69 
70 		spin_unlock(&gman->lock);
71 
72 	} while (ret == -EAGAIN);
73 
74 	if (likely(ret == 0)) {
75 		mem->mm_node = gman;
76 		mem->start = id;
77 	}
78 
79 	return ret;
80 }
81 
82 static void vmw_gmrid_man_put_node(struct ttm_mem_type_manager *man,
83 				   struct ttm_mem_reg *mem)
84 {
85 	struct vmwgfx_gmrid_man *gman =
86 		(struct vmwgfx_gmrid_man *)man->priv;
87 
88 	if (mem->mm_node) {
89 		spin_lock(&gman->lock);
90 		ida_remove(&gman->gmr_ida, mem->start);
91 		spin_unlock(&gman->lock);
92 		mem->mm_node = NULL;
93 	}
94 }
95 
96 static int vmw_gmrid_man_init(struct ttm_mem_type_manager *man,
97 			      unsigned long p_size)
98 {
99 	struct vmwgfx_gmrid_man *gman =
100 		kzalloc(sizeof(*gman), GFP_KERNEL);
101 
102 	if (unlikely(gman == NULL))
103 		return -ENOMEM;
104 
105 	spin_lock_init(&gman->lock);
106 	ida_init(&gman->gmr_ida);
107 	gman->max_gmr_ids = p_size;
108 	man->priv = (void *) gman;
109 	return 0;
110 }
111 
112 static int vmw_gmrid_man_takedown(struct ttm_mem_type_manager *man)
113 {
114 	struct vmwgfx_gmrid_man *gman =
115 		(struct vmwgfx_gmrid_man *)man->priv;
116 
117 	if (gman) {
118 		ida_destroy(&gman->gmr_ida);
119 		kfree(gman);
120 	}
121 	return 0;
122 }
123 
124 static void vmw_gmrid_man_debug(struct ttm_mem_type_manager *man,
125 				const char *prefix)
126 {
127 	printk(KERN_INFO "%s: No debug info available for the GMR "
128 	       "id manager.\n", prefix);
129 }
130 
131 const struct ttm_mem_type_manager_func vmw_gmrid_manager_func = {
132 	vmw_gmrid_man_init,
133 	vmw_gmrid_man_takedown,
134 	vmw_gmrid_man_get_node,
135 	vmw_gmrid_man_put_node,
136 	vmw_gmrid_man_debug
137 };
138