xref: /openbmc/linux/drivers/gpu/drm/omapdrm/tcm.h (revision bc05aa6e)
1 /*
2  * TILER container manager specification and support functions for TI
3  * TILER driver.
4  *
5  * Author: Lajos Molnar <molnar@ti.com>
6  *
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * * Redistributions of source code must retain the above copyright
14  *   notice, this list of conditions and the following disclaimer.
15  *
16  * * Redistributions in binary form must reproduce the above copyright
17  *   notice, this list of conditions and the following disclaimer in the
18  *   documentation and/or other materials provided with the distribution.
19  *
20  * * Neither the name of Texas Instruments Incorporated nor the names of
21  *   its contributors may be used to endorse or promote products derived
22  *   from this software without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
26  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
27  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
28  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
29  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
30  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
31  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
32  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
33  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
34  * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 #ifndef TCM_H
38 #define TCM_H
39 
40 struct tcm;
41 
42 /* point */
43 struct tcm_pt {
44 	u16 x;
45 	u16 y;
46 };
47 
48 /* 1d or 2d area */
49 struct tcm_area {
50 	bool is2d;		/* whether area is 1d or 2d */
51 	struct tcm    *tcm;	/* parent */
52 	struct tcm_pt  p0;
53 	struct tcm_pt  p1;
54 };
55 
56 struct tcm {
57 	u16 width, height;	/* container dimensions */
58 	int lut_id;		/* Lookup table identifier */
59 
60 	unsigned int y_offset;	/* offset to use for y coordinates */
61 
62 	spinlock_t lock;
63 	unsigned long *bitmap;
64 	size_t map_size;
65 
66 	/* function table */
67 	s32 (*reserve_2d)(struct tcm *tcm, u16 height, u16 width, u16 align,
68 			  int16_t offset, uint16_t slot_bytes,
69 			  struct tcm_area *area);
70 	s32 (*reserve_1d)(struct tcm *tcm, u32 slots, struct tcm_area *area);
71 	s32 (*free)(struct tcm *tcm, struct tcm_area *area);
72 	void (*deinit)(struct tcm *tcm);
73 };
74 
75 /*=============================================================================
76     BASIC TILER CONTAINER MANAGER INTERFACE
77 =============================================================================*/
78 
79 /*
80  * NOTE:
81  *
82  * Since some basic parameter checking is done outside the TCM algorithms,
83  * TCM implementation do NOT have to check the following:
84  *
85  *   area pointer is NULL
86  *   width and height fits within container
87  *   number of pages is more than the size of the container
88  *
89  */
90 
91 struct tcm *sita_init(u16 width, u16 height);
92 
93 
94 /**
95  * Deinitialize tiler container manager.
96  *
97  * @param tcm	Pointer to container manager.
98  *
99  * @return 0 on success, non-0 error value on error.  The call
100  *	   should free as much memory as possible and meaningful
101  *	   even on failure.  Some error codes: -ENODEV: invalid
102  *	   manager.
103  */
104 static inline void tcm_deinit(struct tcm *tcm)
105 {
106 	if (tcm)
107 		tcm->deinit(tcm);
108 }
109 
110 /**
111  * Reserves a 2D area in the container.
112  *
113  * @param tcm		Pointer to container manager.
114  * @param height	Height(in pages) of area to be reserved.
115  * @param width		Width(in pages) of area to be reserved.
116  * @param align		Alignment requirement for top-left corner of area. Not
117  *			all values may be supported by the container manager,
118  *			but it must support 0 (1), 32 and 64.
119  *			0 value is equivalent to 1.
120  * @param offset	Offset requirement, in bytes.  This is the offset
121  *			from a 4KiB aligned virtual address.
122  * @param slot_bytes	Width of slot in bytes
123  * @param area		Pointer to where the reserved area should be stored.
124  *
125  * @return 0 on success.  Non-0 error code on failure.  Also,
126  *	   the tcm field of the area will be set to NULL on
127  *	   failure.  Some error codes: -ENODEV: invalid manager,
128  *	   -EINVAL: invalid area, -ENOMEM: not enough space for
129  *	    allocation.
130  */
131 static inline s32 tcm_reserve_2d(struct tcm *tcm, u16 width, u16 height,
132 				u16 align, int16_t offset, uint16_t slot_bytes,
133 				struct tcm_area *area)
134 {
135 	/* perform rudimentary error checking */
136 	s32 res = tcm  == NULL ? -ENODEV :
137 		(area == NULL || width == 0 || height == 0 ||
138 		 /* align must be a 2 power */
139 		 (align & (align - 1))) ? -EINVAL :
140 		(height > tcm->height || width > tcm->width) ? -ENOMEM : 0;
141 
142 	if (!res) {
143 		area->is2d = true;
144 		res = tcm->reserve_2d(tcm, height, width, align, offset,
145 					slot_bytes, area);
146 		area->tcm = res ? NULL : tcm;
147 	}
148 
149 	return res;
150 }
151 
152 /**
153  * Reserves a 1D area in the container.
154  *
155  * @param tcm		Pointer to container manager.
156  * @param slots		Number of (contiguous) slots to reserve.
157  * @param area		Pointer to where the reserved area should be stored.
158  *
159  * @return 0 on success.  Non-0 error code on failure.  Also,
160  *	   the tcm field of the area will be set to NULL on
161  *	   failure.  Some error codes: -ENODEV: invalid manager,
162  *	   -EINVAL: invalid area, -ENOMEM: not enough space for
163  *	    allocation.
164  */
165 static inline s32 tcm_reserve_1d(struct tcm *tcm, u32 slots,
166 				 struct tcm_area *area)
167 {
168 	/* perform rudimentary error checking */
169 	s32 res = tcm  == NULL ? -ENODEV :
170 		(area == NULL || slots == 0) ? -EINVAL :
171 		slots > (tcm->width * (u32) tcm->height) ? -ENOMEM : 0;
172 
173 	if (!res) {
174 		area->is2d = false;
175 		res = tcm->reserve_1d(tcm, slots, area);
176 		area->tcm = res ? NULL : tcm;
177 	}
178 
179 	return res;
180 }
181 
182 /**
183  * Free a previously reserved area from the container.
184  *
185  * @param area	Pointer to area reserved by a prior call to
186  *		tcm_reserve_1d or tcm_reserve_2d call, whether
187  *		it was successful or not. (Note: all fields of
188  *		the structure must match.)
189  *
190  * @return 0 on success.  Non-0 error code on failure.  Also, the tcm
191  *	   field of the area is set to NULL on success to avoid subsequent
192  *	   freeing.  This call will succeed even if supplying
193  *	   the area from a failed reserved call.
194  */
195 static inline s32 tcm_free(struct tcm_area *area)
196 {
197 	s32 res = 0; /* free succeeds by default */
198 
199 	if (area && area->tcm) {
200 		res = area->tcm->free(area->tcm, area);
201 		if (res == 0)
202 			area->tcm = NULL;
203 	}
204 
205 	return res;
206 }
207 
208 /*=============================================================================
209     HELPER FUNCTION FOR ANY TILER CONTAINER MANAGER
210 =============================================================================*/
211 
212 /**
213  * This method slices off the topmost 2D slice from the parent area, and stores
214  * it in the 'slice' parameter.  The 'parent' parameter will get modified to
215  * contain the remaining portion of the area.  If the whole parent area can
216  * fit in a 2D slice, its tcm pointer is set to NULL to mark that it is no
217  * longer a valid area.
218  *
219  * @param parent	Pointer to a VALID parent area that will get modified
220  * @param slice		Pointer to the slice area that will get modified
221  */
222 static inline void tcm_slice(struct tcm_area *parent, struct tcm_area *slice)
223 {
224 	*slice = *parent;
225 
226 	/* check if we need to slice */
227 	if (slice->tcm && !slice->is2d &&
228 		slice->p0.y != slice->p1.y &&
229 		(slice->p0.x || (slice->p1.x != slice->tcm->width - 1))) {
230 		/* set end point of slice (start always remains) */
231 		slice->p1.x = slice->tcm->width - 1;
232 		slice->p1.y = (slice->p0.x) ? slice->p0.y : slice->p1.y - 1;
233 		/* adjust remaining area */
234 		parent->p0.x = 0;
235 		parent->p0.y = slice->p1.y + 1;
236 	} else {
237 		/* mark this as the last slice */
238 		parent->tcm = NULL;
239 	}
240 }
241 
242 /* Verify if a tcm area is logically valid */
243 static inline bool tcm_area_is_valid(struct tcm_area *area)
244 {
245 	return area && area->tcm &&
246 		/* coordinate bounds */
247 		area->p1.x < area->tcm->width &&
248 		area->p1.y < area->tcm->height &&
249 		area->p0.y <= area->p1.y &&
250 		/* 1D coordinate relationship + p0.x check */
251 		((!area->is2d &&
252 		  area->p0.x < area->tcm->width &&
253 		  area->p0.x + area->p0.y * area->tcm->width <=
254 		  area->p1.x + area->p1.y * area->tcm->width) ||
255 		 /* 2D coordinate relationship */
256 		 (area->is2d &&
257 		  area->p0.x <= area->p1.x));
258 }
259 
260 /* see if a coordinate is within an area */
261 static inline bool __tcm_is_in(struct tcm_pt *p, struct tcm_area *a)
262 {
263 	u16 i;
264 
265 	if (a->is2d) {
266 		return p->x >= a->p0.x && p->x <= a->p1.x &&
267 		       p->y >= a->p0.y && p->y <= a->p1.y;
268 	} else {
269 		i = p->x + p->y * a->tcm->width;
270 		return i >= a->p0.x + a->p0.y * a->tcm->width &&
271 		       i <= a->p1.x + a->p1.y * a->tcm->width;
272 	}
273 }
274 
275 /* calculate area width */
276 static inline u16 __tcm_area_width(struct tcm_area *area)
277 {
278 	return area->p1.x - area->p0.x + 1;
279 }
280 
281 /* calculate area height */
282 static inline u16 __tcm_area_height(struct tcm_area *area)
283 {
284 	return area->p1.y - area->p0.y + 1;
285 }
286 
287 /* calculate number of slots in an area */
288 static inline u16 __tcm_sizeof(struct tcm_area *area)
289 {
290 	return area->is2d ?
291 		__tcm_area_width(area) * __tcm_area_height(area) :
292 		(area->p1.x - area->p0.x + 1) + (area->p1.y - area->p0.y) *
293 							area->tcm->width;
294 }
295 #define tcm_sizeof(area) __tcm_sizeof(&(area))
296 #define tcm_awidth(area) __tcm_area_width(&(area))
297 #define tcm_aheight(area) __tcm_area_height(&(area))
298 #define tcm_is_in(pt, area) __tcm_is_in(&(pt), &(area))
299 
300 /* limit a 1D area to the first N pages */
301 static inline s32 tcm_1d_limit(struct tcm_area *a, u32 num_pg)
302 {
303 	if (__tcm_sizeof(a) < num_pg)
304 		return -ENOMEM;
305 	if (!num_pg)
306 		return -EINVAL;
307 
308 	a->p1.x = (a->p0.x + num_pg - 1) % a->tcm->width;
309 	a->p1.y = a->p0.y + ((a->p0.x + num_pg - 1) / a->tcm->width);
310 	return 0;
311 }
312 
313 /**
314  * Iterate through 2D slices of a valid area. Behaves
315  * syntactically as a for(;;) statement.
316  *
317  * @param var		Name of a local variable of type 'struct
318  *			tcm_area *' that will get modified to
319  *			contain each slice.
320  * @param area		Pointer to the VALID parent area. This
321  *			structure will not get modified
322  *			throughout the loop.
323  *
324  */
325 #define tcm_for_each_slice(var, area, safe) \
326 	for (safe = area, \
327 	     tcm_slice(&safe, &var); \
328 	     var.tcm; tcm_slice(&safe, &var))
329 
330 #endif
331