xref: /linux/drivers/gpu/drm/xe/xe_guc_id_mgr.c (revision 4b132aacb0768ac1e652cf517097ea6f237214b9)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2024 Intel Corporation
4  */
5 
6 #include <linux/bitmap.h>
7 #include <linux/mutex.h>
8 
9 #include <drm/drm_managed.h>
10 
11 #include "xe_assert.h"
12 #include "xe_gt_printk.h"
13 #include "xe_guc.h"
14 #include "xe_guc_id_mgr.h"
15 #include "xe_guc_types.h"
16 
17 static struct xe_guc *idm_to_guc(struct xe_guc_id_mgr *idm)
18 {
19 	return container_of(idm, struct xe_guc, submission_state.idm);
20 }
21 
22 static struct xe_gt *idm_to_gt(struct xe_guc_id_mgr *idm)
23 {
24 	return guc_to_gt(idm_to_guc(idm));
25 }
26 
27 static struct xe_device *idm_to_xe(struct xe_guc_id_mgr *idm)
28 {
29 	return gt_to_xe(idm_to_gt(idm));
30 }
31 
32 #define idm_assert(idm, cond)		xe_gt_assert(idm_to_gt(idm), cond)
33 #define idm_mutex(idm)			(&idm_to_guc(idm)->submission_state.lock)
34 
35 static void idm_print_locked(struct xe_guc_id_mgr *idm, struct drm_printer *p, int indent);
36 
37 static void __fini_idm(struct drm_device *drm, void *arg)
38 {
39 	struct xe_guc_id_mgr *idm = arg;
40 
41 	mutex_lock(idm_mutex(idm));
42 
43 	if (IS_ENABLED(CONFIG_DRM_XE_DEBUG)) {
44 		unsigned int weight = bitmap_weight(idm->bitmap, idm->total);
45 
46 		if (weight) {
47 			struct drm_printer p = xe_gt_info_printer(idm_to_gt(idm));
48 
49 			xe_gt_err(idm_to_gt(idm), "GUC ID manager unclean (%u/%u)\n",
50 				  weight, idm->total);
51 			idm_print_locked(idm, &p, 1);
52 		}
53 	}
54 
55 	bitmap_free(idm->bitmap);
56 	idm->bitmap = NULL;
57 	idm->total = 0;
58 	idm->used = 0;
59 
60 	mutex_unlock(idm_mutex(idm));
61 }
62 
63 /**
64  * xe_guc_id_mgr_init() - Initialize GuC context ID Manager.
65  * @idm: the &xe_guc_id_mgr to initialize
66  * @limit: number of IDs to manage
67  *
68  * The bare-metal or PF driver can pass ~0 as &limit to indicate that all
69  * context IDs supported by the GuC firmware are available for use.
70  *
71  * Only VF drivers will have to provide explicit number of context IDs
72  * that they can use.
73  *
74  * Return: 0 on success or a negative error code on failure.
75  */
76 int xe_guc_id_mgr_init(struct xe_guc_id_mgr *idm, unsigned int limit)
77 {
78 	int ret;
79 
80 	idm_assert(idm, !idm->bitmap);
81 	idm_assert(idm, !idm->total);
82 	idm_assert(idm, !idm->used);
83 
84 	if (limit == ~0)
85 		limit = GUC_ID_MAX;
86 	else if (limit > GUC_ID_MAX)
87 		return -ERANGE;
88 	else if (!limit)
89 		return -EINVAL;
90 
91 	idm->bitmap = bitmap_zalloc(limit, GFP_KERNEL);
92 	if (!idm->bitmap)
93 		return -ENOMEM;
94 	idm->total = limit;
95 
96 	ret = drmm_add_action_or_reset(&idm_to_xe(idm)->drm, __fini_idm, idm);
97 	if (ret)
98 		return ret;
99 
100 	xe_gt_info(idm_to_gt(idm), "using %u GUC ID%s\n",
101 		   idm->total, str_plural(idm->total));
102 	return 0;
103 }
104 
105 static unsigned int find_last_zero_area(unsigned long *bitmap,
106 					unsigned int total,
107 					unsigned int count)
108 {
109 	unsigned int found = total;
110 	unsigned int rs, re, range;
111 
112 	for_each_clear_bitrange(rs, re, bitmap, total) {
113 		range = re - rs;
114 		if (range < count)
115 			continue;
116 		found = rs + (range - count);
117 	}
118 	return found;
119 }
120 
121 static int idm_reserve_chunk_locked(struct xe_guc_id_mgr *idm,
122 				    unsigned int count, unsigned int retain)
123 {
124 	int id;
125 
126 	idm_assert(idm, count);
127 	lockdep_assert_held(idm_mutex(idm));
128 
129 	if (!idm->total)
130 		return -ENODATA;
131 
132 	if (retain) {
133 		/*
134 		 * For IDs reservations (used on PF for VFs) we want to make
135 		 * sure there will be at least 'retain' available for the PF
136 		 */
137 		if (idm->used + count + retain > idm->total)
138 			return -EDQUOT;
139 		/*
140 		 * ... and we want to reserve highest IDs close to the end.
141 		 */
142 		id = find_last_zero_area(idm->bitmap, idm->total, count);
143 	} else {
144 		/*
145 		 * For regular IDs reservations (used by submission code)
146 		 * we start searching from the lower range of IDs.
147 		 */
148 		id = bitmap_find_next_zero_area(idm->bitmap, idm->total, 0, count, 0);
149 	}
150 	if (id >= idm->total)
151 		return -ENOSPC;
152 
153 	bitmap_set(idm->bitmap, id, count);
154 	idm->used += count;
155 
156 	return id;
157 }
158 
159 static void idm_release_chunk_locked(struct xe_guc_id_mgr *idm,
160 				     unsigned int start, unsigned int count)
161 {
162 	idm_assert(idm, count);
163 	idm_assert(idm, count <= idm->used);
164 	idm_assert(idm, start < idm->total);
165 	idm_assert(idm, start + count - 1 < idm->total);
166 	lockdep_assert_held(idm_mutex(idm));
167 
168 	if (IS_ENABLED(CONFIG_DRM_XE_DEBUG)) {
169 		unsigned int n;
170 
171 		for (n = 0; n < count; n++)
172 			idm_assert(idm, test_bit(start + n, idm->bitmap));
173 	}
174 	bitmap_clear(idm->bitmap, start, count);
175 	idm->used -= count;
176 }
177 
178 /**
179  * xe_guc_id_mgr_reserve_locked() - Reserve one or more GuC context IDs.
180  * @idm: the &xe_guc_id_mgr
181  * @count: number of IDs to allocate (can't be 0)
182  *
183  * This function is dedicated for the use by the GuC submission code,
184  * where submission lock is already taken.
185  *
186  * Return: ID of allocated GuC context or a negative error code on failure.
187  */
188 int xe_guc_id_mgr_reserve_locked(struct xe_guc_id_mgr *idm, unsigned int count)
189 {
190 	return idm_reserve_chunk_locked(idm, count, 0);
191 }
192 
193 /**
194  * xe_guc_id_mgr_release_locked() - Release one or more GuC context IDs.
195  * @idm: the &xe_guc_id_mgr
196  * @id: the GuC context ID to release
197  * @count: number of IDs to release (can't be 0)
198  *
199  * This function is dedicated for the use by the GuC submission code,
200  * where submission lock is already taken.
201  */
202 void xe_guc_id_mgr_release_locked(struct xe_guc_id_mgr *idm, unsigned int id,
203 				  unsigned int count)
204 {
205 	return idm_release_chunk_locked(idm, id, count);
206 }
207 
208 /**
209  * xe_guc_id_mgr_reserve() - Reserve a range of GuC context IDs.
210  * @idm: the &xe_guc_id_mgr
211  * @count: number of GuC context IDs to reserve (can't be 0)
212  * @retain: number of GuC context IDs to keep available (can't be 0)
213  *
214  * This function is dedicated for the use by the PF driver which expects that
215  * reserved range of IDs will be contiguous and that there will be at least
216  * &retain IDs still available for the PF after this reservation.
217  *
218  * Return: starting ID of the allocated GuC context ID range or
219  *         a negative error code on failure.
220  */
221 int xe_guc_id_mgr_reserve(struct xe_guc_id_mgr *idm,
222 			  unsigned int count, unsigned int retain)
223 {
224 	int ret;
225 
226 	idm_assert(idm, count);
227 	idm_assert(idm, retain);
228 
229 	mutex_lock(idm_mutex(idm));
230 	ret = idm_reserve_chunk_locked(idm, count, retain);
231 	mutex_unlock(idm_mutex(idm));
232 
233 	return ret;
234 }
235 
236 /**
237  * xe_guc_id_mgr_release() - Release a range of GuC context IDs.
238  * @idm: the &xe_guc_id_mgr
239  * @start: the starting ID of GuC context range to release
240  * @count: number of GuC context IDs to release
241  */
242 void xe_guc_id_mgr_release(struct xe_guc_id_mgr *idm,
243 			   unsigned int start, unsigned int count)
244 {
245 	mutex_lock(idm_mutex(idm));
246 	idm_release_chunk_locked(idm, start, count);
247 	mutex_unlock(idm_mutex(idm));
248 }
249 
250 static void idm_print_locked(struct xe_guc_id_mgr *idm, struct drm_printer *p, int indent)
251 {
252 	unsigned int rs, re;
253 
254 	lockdep_assert_held(idm_mutex(idm));
255 
256 	drm_printf_indent(p, indent, "total %u\n", idm->total);
257 	if (!idm->bitmap)
258 		return;
259 
260 	drm_printf_indent(p, indent, "used %u\n", idm->used);
261 	for_each_set_bitrange(rs, re, idm->bitmap, idm->total)
262 		drm_printf_indent(p, indent, "range %u..%u (%u)\n", rs, re - 1, re - rs);
263 }
264 
265 /**
266  * xe_guc_id_mgr_print() - Print status of GuC ID Manager.
267  * @idm: the &xe_guc_id_mgr to print
268  * @p: the &drm_printer to print to
269  * @indent: tab indentation level
270  */
271 void xe_guc_id_mgr_print(struct xe_guc_id_mgr *idm, struct drm_printer *p, int indent)
272 {
273 	mutex_lock(idm_mutex(idm));
274 	idm_print_locked(idm, p, indent);
275 	mutex_unlock(idm_mutex(idm));
276 }
277 
278 #if IS_BUILTIN(CONFIG_DRM_XE_KUNIT_TEST)
279 #include "tests/xe_guc_id_mgr_test.c"
280 #endif
281