1 /*	$NetBSD: ttm_tt.h,v 1.7 2021/12/19 12:29:16 riastradh Exp $	*/
2 
3 /**************************************************************************
4  *
5  * Copyright (c) 2006-2009 Vmware, Inc., Palo Alto, CA., USA
6  * All Rights Reserved.
7  *
8  * Permission is hereby granted, free of charge, to any person obtaining a
9  * copy of this software and associated documentation files (the
10  * "Software"), to deal in the Software without restriction, including
11  * without limitation the rights to use, copy, modify, merge, publish,
12  * distribute, sub license, and/or sell copies of the Software, and to
13  * permit persons to whom the Software is furnished to do so, subject to
14  * the following conditions:
15  *
16  * The above copyright notice and this permission notice (including the
17  * next paragraph) shall be included in all copies or substantial portions
18  * of the Software.
19  *
20  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
21  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
23  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
24  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
25  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
26  * USE OR OTHER DEALINGS IN THE SOFTWARE.
27  *
28  **************************************************************************/
29 #ifndef _TTM_TT_H_
30 #define _TTM_TT_H_
31 
32 #include <linux/types.h>
33 
34 struct ttm_tt;
35 struct ttm_mem_reg;
36 struct ttm_buffer_object;
37 struct ttm_operation_ctx;
38 
39 #define TTM_PAGE_FLAG_WRITE           (1 << 3)
40 #define TTM_PAGE_FLAG_SWAPPED         (1 << 4)
41 #define TTM_PAGE_FLAG_PERSISTENT_SWAP (1 << 5)
42 #define TTM_PAGE_FLAG_ZERO_ALLOC      (1 << 6)
43 #define TTM_PAGE_FLAG_DMA32           (1 << 7)
44 #define TTM_PAGE_FLAG_SG              (1 << 8)
45 #define TTM_PAGE_FLAG_NO_RETRY	      (1 << 9)
46 
47 enum ttm_caching_state {
48 	tt_uncached,
49 	tt_wc,
50 	tt_cached
51 };
52 
53 struct ttm_backend_func {
54 	/**
55 	 * struct ttm_backend_func member bind
56 	 *
57 	 * @ttm: Pointer to a struct ttm_tt.
58 	 * @bo_mem: Pointer to a struct ttm_mem_reg describing the
59 	 * memory type and location for binding.
60 	 *
61 	 * Bind the backend pages into the aperture in the location
62 	 * indicated by @bo_mem. This function should be able to handle
63 	 * differences between aperture and system page sizes.
64 	 */
65 	int (*bind) (struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem);
66 
67 	/**
68 	 * struct ttm_backend_func member unbind
69 	 *
70 	 * @ttm: Pointer to a struct ttm_tt.
71 	 *
72 	 * Unbind previously bound backend pages. This function should be
73 	 * able to handle differences between aperture and system page sizes.
74 	 */
75 	int (*unbind) (struct ttm_tt *ttm);
76 
77 	/**
78 	 * struct ttm_backend_func member destroy
79 	 *
80 	 * @ttm: Pointer to a struct ttm_tt.
81 	 *
82 	 * Destroy the backend. This will be call back from ttm_tt_destroy so
83 	 * don't call ttm_tt_destroy from the callback or infinite loop.
84 	 */
85 	void (*destroy) (struct ttm_tt *ttm);
86 };
87 
88 /**
89  * struct ttm_tt
90  *
91  * @bdev: Pointer to a struct ttm_bo_device.
92  * @func: Pointer to a struct ttm_backend_func that describes
93  * the backend methods.
94  * pointer.
95  * @pages: Array of pages backing the data.
96  * @num_pages: Number of pages in the page array.
97  * @bdev: Pointer to the current struct ttm_bo_device.
98  * @be: Pointer to the ttm backend.
99  * @swap_storage: Pointer to shmem struct file for swap storage.
100  * @caching_state: The current caching state of the pages.
101  * @state: The current binding state of the pages.
102  *
103  * This is a structure holding the pages, caching- and aperture binding
104  * status for a buffer object that isn't backed by fixed (VRAM / AGP)
105  * memory.
106  */
107 struct ttm_tt {
108 	struct ttm_bo_device *bdev;
109 	const struct ttm_backend_func *func;
110 	struct page **pages;
111 	uint32_t page_flags;
112 	unsigned long num_pages;
113 	struct sg_table *sg; /* for SG objects via dma-buf */
114 #ifdef __NetBSD__
115 	struct uvm_object *swap_storage;
116 #else
117 	struct file *swap_storage;
118 #endif
119 	enum ttm_caching_state caching_state;
120 	enum {
121 		tt_bound,
122 		tt_unbound,
123 		tt_unpopulated,
124 	} state;
125 };
126 
127 /**
128  * struct ttm_dma_tt
129  *
130  * @ttm: Base ttm_tt struct.
131  * @dma_address: The DMA (bus) addresses of the pages
132  * @pages_list: used by some page allocation backend
133  *
134  * This is a structure holding the pages, caching- and aperture binding
135  * status for a buffer object that isn't backed by fixed (VRAM / AGP)
136  * memory.
137  */
138 struct ttm_dma_tt {
139 	struct ttm_tt ttm;
140 #ifdef __NetBSD__
141 	bus_dmamap_t dma_address;
142 #else
143 	dma_addr_t *dma_address;
144 #endif
145 	struct list_head pages_list;
146 };
147 
148 /**
149  * ttm_tt_create
150  *
151  * @bo: pointer to a struct ttm_buffer_object
152  * @zero_alloc: true if allocated pages needs to be zeroed
153  *
154  * Make sure we have a TTM structure allocated for the given BO.
155  * No pages are actually allocated.
156  */
157 int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc);
158 
159 /**
160  * ttm_tt_init
161  *
162  * @ttm: The struct ttm_tt.
163  * @bo: The buffer object we create the ttm for.
164  * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
165  *
166  * Create a struct ttm_tt to back data with system memory pages.
167  * No pages are actually allocated.
168  * Returns:
169  * NULL: Out of memory.
170  */
171 int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,
172 		uint32_t page_flags);
173 int ttm_dma_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_buffer_object *bo,
174 		    uint32_t page_flags);
175 int ttm_sg_tt_init(struct ttm_dma_tt *ttm_dma, struct ttm_buffer_object *bo,
176 		   uint32_t page_flags);
177 
178 /**
179  * ttm_tt_fini
180  *
181  * @ttm: the ttm_tt structure.
182  *
183  * Free memory of ttm_tt structure
184  */
185 void ttm_tt_fini(struct ttm_tt *ttm);
186 void ttm_dma_tt_fini(struct ttm_dma_tt *ttm_dma);
187 
188 /**
189  * ttm_ttm_bind:
190  *
191  * @ttm: The struct ttm_tt containing backing pages.
192  * @bo_mem: The struct ttm_mem_reg identifying the binding location.
193  *
194  * Bind the pages of @ttm to an aperture location identified by @bo_mem
195  */
196 int ttm_tt_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem,
197 		struct ttm_operation_ctx *ctx);
198 
199 /**
200  * ttm_ttm_destroy:
201  *
202  * @ttm: The struct ttm_tt.
203  *
204  * Unbind, unpopulate and destroy common struct ttm_tt.
205  */
206 void ttm_tt_destroy(struct ttm_tt *ttm);
207 
208 /**
209  * ttm_ttm_unbind:
210  *
211  * @ttm: The struct ttm_tt.
212  *
213  * Unbind a struct ttm_tt.
214  */
215 void ttm_tt_unbind(struct ttm_tt *ttm);
216 
217 #ifdef __NetBSD__
218 /**
219  * ttm_tt_wire
220  *
221  * @ttm The struct ttm_tt.
222  *
223  * Wire the pages of a ttm_tt, allocating pages for it if necessary.
224  */
225 extern int ttm_tt_wire(struct ttm_tt *ttm);
226 
227 /**
228  * ttm_tt_unwire
229  *
230  * @ttm The struct ttm_tt.
231  *
232  * Unwire the pages of a ttm_tt.
233  */
234 extern void ttm_tt_unwire(struct ttm_tt *ttm);
235 #else
236 /**
237  * ttm_tt_swapin:
238  *
239  * @ttm: The struct ttm_tt.
240  *
241  * Swap in a previously swap out ttm_tt.
242  */
243 int ttm_tt_swapin(struct ttm_tt *ttm);
244 #endif
245 
246 /**
247  * ttm_tt_set_placement_caching:
248  *
249  * @ttm A struct ttm_tt the backing pages of which will change caching policy.
250  * @placement: Flag indicating the desired caching policy.
251  *
252  * This function will change caching policy of any default kernel mappings of
253  * the pages backing @ttm. If changing from cached to uncached or
254  * write-combined,
255  * all CPU caches will first be flushed to make sure the data of the pages
256  * hit RAM. This function may be very costly as it involves global TLB
257  * and cache flushes and potential page splitting / combining.
258  */
259 int ttm_tt_set_placement_caching(struct ttm_tt *ttm, uint32_t placement);
260 int ttm_tt_swapout(struct ttm_tt *ttm, struct file *persistent_swap_storage);
261 
262 /**
263  * ttm_tt_populate - allocate pages for a ttm
264  *
265  * @ttm: Pointer to the ttm_tt structure
266  *
267  * Calls the driver method to allocate pages for a ttm
268  */
269 int ttm_tt_populate(struct ttm_tt *ttm, struct ttm_operation_ctx *ctx);
270 
271 /**
272  * ttm_tt_unpopulate - free pages from a ttm
273  *
274  * @ttm: Pointer to the ttm_tt structure
275  *
276  * Calls the driver method to free all pages from a ttm
277  */
278 void ttm_tt_unpopulate(struct ttm_tt *ttm);
279 
280 #if IS_ENABLED(CONFIG_AGP)
281 #include <linux/agp_backend.h>
282 
283 /**
284  * ttm_agp_tt_create
285  *
286  * @bo: Buffer object we allocate the ttm for.
287  * @bridge: The agp bridge this device is sitting on.
288  * @page_flags: Page flags as identified by TTM_PAGE_FLAG_XX flags.
289  *
290  *
291  * Create a TTM backend that uses the indicated AGP bridge as an aperture
292  * for TT memory. This function uses the linux agpgart interface to
293  * bind and unbind memory backing a ttm_tt.
294  */
295 struct ttm_tt *ttm_agp_tt_create(struct ttm_buffer_object *bo,
296 				 struct agp_bridge_data *bridge,
297 				 uint32_t page_flags);
298 int ttm_agp_tt_populate(struct ttm_tt *ttm, struct ttm_operation_ctx *ctx);
299 void ttm_agp_tt_unpopulate(struct ttm_tt *ttm);
300 #endif
301 
302 #endif
303