xref: /linux/drivers/gpu/drm/xe/xe_sysctrl_mailbox.c (revision 6505114e82e7541414b176b5da4a3c015a1214ea)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2026 Intel Corporation
4  */
5 
6 #include <linux/bitfield.h>
7 #include <linux/cleanup.h>
8 #include <linux/minmax.h>
9 #include <linux/slab.h>
10 #include <linux/string.h>
11 
12 #include "regs/xe_sysctrl_regs.h"
13 #include "xe_device.h"
14 #include "xe_mmio.h"
15 #include "xe_pm.h"
16 #include "xe_printk.h"
17 #include "xe_sysctrl.h"
18 #include "xe_sysctrl_mailbox.h"
19 #include "xe_sysctrl_mailbox_types.h"
20 
21 struct xe_sysctrl_mailbox_msg_hdr {
22 	__le32 data;
23 } __packed;
24 
25 #define XE_SYSCTRL_HDR_GROUP_ID(hdr) \
26 	FIELD_GET(SYSCTRL_HDR_GROUP_ID_MASK, le32_to_cpu((hdr)->data))
27 
28 #define XE_SYSCTRL_HDR_COMMAND(hdr) \
29 	FIELD_GET(SYSCTRL_HDR_COMMAND_MASK, le32_to_cpu((hdr)->data))
30 
31 #define XE_SYSCTRL_HDR_IS_RESPONSE(hdr) \
32 	FIELD_GET(SYSCTRL_HDR_IS_RESPONSE, le32_to_cpu((hdr)->data))
33 
34 #define XE_SYSCTRL_HDR_RESULT(hdr) \
35 	FIELD_GET(SYSCTRL_HDR_RESULT_MASK, le32_to_cpu((hdr)->data))
36 
37 static bool sysctrl_wait_bit_clear(struct xe_sysctrl *sc, u32 bit_mask,
38 				   unsigned int timeout_ms)
39 {
40 	int ret;
41 
42 	ret = xe_mmio_wait32_not(sc->mmio, SYSCTRL_MB_CTRL, bit_mask, bit_mask,
43 				 timeout_ms * 1000, NULL, false);
44 
45 	return ret == 0;
46 }
47 
48 static bool sysctrl_wait_bit_set(struct xe_sysctrl *sc, u32 bit_mask,
49 				 unsigned int timeout_ms)
50 {
51 	int ret;
52 
53 	ret = xe_mmio_wait32(sc->mmio, SYSCTRL_MB_CTRL, bit_mask, bit_mask,
54 			     timeout_ms * 1000, NULL, false);
55 
56 	return ret == 0;
57 }
58 
59 static int sysctrl_write_frame(struct xe_sysctrl *sc, const void *frame,
60 			       size_t len)
61 {
62 	static const struct xe_reg regs[] = {
63 		SYSCTRL_MB_DATA0, SYSCTRL_MB_DATA1, SYSCTRL_MB_DATA2, SYSCTRL_MB_DATA3
64 	};
65 	struct xe_device *xe = sc_to_xe(sc);
66 	u32 val[XE_SYSCTRL_MB_FRAME_SIZE / sizeof(u32)] = {0};
67 	u32 dw = DIV_ROUND_UP(len, sizeof(u32));
68 	u32 i;
69 
70 	xe_assert(xe, len > 0 && len <= XE_SYSCTRL_MB_FRAME_SIZE);
71 
72 	memcpy(val, frame, len);
73 
74 	for (i = 0; i < dw; i++)
75 		xe_mmio_write32(sc->mmio, regs[i], val[i]);
76 
77 	return 0;
78 }
79 
80 static int sysctrl_read_frame(struct xe_sysctrl *sc, void *frame,
81 			      size_t len)
82 {
83 	static const struct xe_reg regs[] = {
84 		SYSCTRL_MB_DATA0, SYSCTRL_MB_DATA1, SYSCTRL_MB_DATA2, SYSCTRL_MB_DATA3
85 	};
86 	struct xe_device *xe = sc_to_xe(sc);
87 	u32 val[XE_SYSCTRL_MB_FRAME_SIZE / sizeof(u32)] = {0};
88 	u32 dw = DIV_ROUND_UP(len, sizeof(u32));
89 	u32 i;
90 
91 	xe_assert(xe, len > 0 && len <= XE_SYSCTRL_MB_FRAME_SIZE);
92 
93 	for (i = 0; i < dw; i++)
94 		val[i] = xe_mmio_read32(sc->mmio, regs[i]);
95 
96 	memcpy(frame, val, len);
97 
98 	return 0;
99 }
100 
101 static void sysctrl_clear_response(struct xe_sysctrl *sc)
102 {
103 	xe_mmio_rmw32(sc->mmio, SYSCTRL_MB_CTRL, SYSCTRL_MB_CTRL_RUN_BUSY_OUT, 0);
104 }
105 
106 static int sysctrl_prepare_command(struct xe_device *xe,
107 				   u8 group_id, u8 command,
108 				   const void *data_in, size_t data_in_len,
109 				   u8 **mbox_cmd, size_t *cmd_size)
110 {
111 	struct xe_sysctrl_mailbox_msg_hdr *hdr;
112 	size_t size;
113 	u8 *buffer;
114 
115 	xe_assert(xe, command <= SYSCTRL_HDR_COMMAND_MAX);
116 
117 	if (data_in_len > XE_SYSCTRL_MB_MAX_MESSAGE_SIZE - sizeof(*hdr)) {
118 		xe_err(xe, "sysctrl: Input data too large: %zu bytes\n", data_in_len);
119 		return -EINVAL;
120 	}
121 
122 	size = sizeof(*hdr) + data_in_len;
123 
124 	buffer = kmalloc(size, GFP_KERNEL);
125 	if (!buffer)
126 		return -ENOMEM;
127 
128 	hdr = (struct xe_sysctrl_mailbox_msg_hdr *)buffer;
129 	hdr->data = cpu_to_le32(FIELD_PREP(SYSCTRL_HDR_GROUP_ID_MASK, group_id) |
130 				     FIELD_PREP(SYSCTRL_HDR_COMMAND_MASK, command));
131 
132 	if (data_in && data_in_len)
133 		memcpy(buffer + sizeof(*hdr), data_in, data_in_len);
134 
135 	*mbox_cmd = buffer;
136 	*cmd_size = size;
137 
138 	return 0;
139 }
140 
141 static int sysctrl_send_frames(struct xe_sysctrl *sc,
142 			       const u8 *mbox_cmd,
143 			       size_t cmd_size, unsigned int timeout_ms)
144 {
145 	struct xe_device *xe = sc_to_xe(sc);
146 	u32 ctrl_reg, total_frames, frame;
147 	size_t bytes_sent, frame_size;
148 
149 	total_frames = DIV_ROUND_UP(cmd_size, XE_SYSCTRL_MB_FRAME_SIZE);
150 
151 	if (!sysctrl_wait_bit_clear(sc, SYSCTRL_MB_CTRL_RUN_BUSY, timeout_ms)) {
152 		xe_err(xe, "sysctrl: Mailbox busy\n");
153 		return -EBUSY;
154 	}
155 
156 	sc->phase_bit ^= 1;
157 	bytes_sent = 0;
158 
159 	for (frame = 0; frame < total_frames; frame++) {
160 		frame_size = min_t(size_t, cmd_size - bytes_sent, XE_SYSCTRL_MB_FRAME_SIZE);
161 
162 		if (sysctrl_write_frame(sc, mbox_cmd + bytes_sent, frame_size)) {
163 			xe_err(xe, "sysctrl: Failed to write frame %u\n", frame);
164 			sc->phase_bit = 0;
165 			return -EIO;
166 		}
167 
168 		ctrl_reg = SYSCTRL_MB_CTRL_RUN_BUSY |
169 			   REG_FIELD_PREP(SYSCTRL_FRAME_CURRENT_MASK, frame) |
170 			   REG_FIELD_PREP(SYSCTRL_FRAME_TOTAL_MASK, total_frames - 1) |
171 			   SYSCTRL_MB_CTRL_CMD |
172 			   (sc->phase_bit ? SYSCTRL_FRAME_PHASE : 0);
173 
174 		xe_mmio_write32(sc->mmio, SYSCTRL_MB_CTRL, ctrl_reg);
175 
176 		if (!sysctrl_wait_bit_clear(sc, SYSCTRL_MB_CTRL_RUN_BUSY, timeout_ms)) {
177 			xe_err(xe, "sysctrl: Frame %u acknowledgment timeout\n", frame);
178 			sc->phase_bit = 0;
179 			return -ETIMEDOUT;
180 		}
181 
182 		bytes_sent += frame_size;
183 	}
184 
185 	return 0;
186 }
187 
188 static int sysctrl_process_frame(struct xe_sysctrl *sc, void *out,
189 				 size_t frame_size, unsigned int timeout_ms,
190 				 bool *done)
191 {
192 	u32 curr_frame, total_frames, ctrl_reg;
193 	struct xe_device *xe = sc_to_xe(sc);
194 	int ret;
195 
196 	if (!sysctrl_wait_bit_set(sc, SYSCTRL_MB_CTRL_RUN_BUSY_OUT, timeout_ms)) {
197 		xe_err(xe, "sysctrl: Response frame timeout\n");
198 		return -ETIMEDOUT;
199 	}
200 
201 	ctrl_reg = xe_mmio_read32(sc->mmio, SYSCTRL_MB_CTRL);
202 	total_frames = FIELD_GET(SYSCTRL_FRAME_TOTAL_MASK, ctrl_reg);
203 	curr_frame = FIELD_GET(SYSCTRL_FRAME_CURRENT_MASK, ctrl_reg);
204 
205 	ret = sysctrl_read_frame(sc, out, frame_size);
206 	if (ret)
207 		return ret;
208 
209 	sysctrl_clear_response(sc);
210 
211 	if (curr_frame == total_frames)
212 		*done = true;
213 
214 	return 0;
215 }
216 
217 static int sysctrl_receive_frames(struct xe_sysctrl *sc,
218 				  const struct xe_sysctrl_mailbox_msg_hdr *req,
219 				  void *data_out, size_t data_out_len,
220 				  size_t *rdata_len, unsigned int timeout_ms)
221 {
222 	struct xe_sysctrl_mailbox_msg_hdr *hdr;
223 	struct xe_device *xe = sc_to_xe(sc);
224 	size_t remain = sizeof(*hdr) + data_out_len;
225 	u8 *buffer __free(kfree) = kzalloc(remain, GFP_KERNEL);
226 	size_t frame_size;
227 	bool done = false;
228 	int ret = 0;
229 	u8 *out;
230 
231 	if (!buffer)
232 		return -ENOMEM;
233 
234 	out = buffer;
235 	while (!done && remain) {
236 		frame_size = min_t(size_t, remain, XE_SYSCTRL_MB_FRAME_SIZE);
237 
238 		ret = sysctrl_process_frame(sc, out, frame_size, timeout_ms,
239 					    &done);
240 		if (ret)
241 			return ret;
242 
243 		remain -= frame_size;
244 		out += frame_size;
245 	}
246 
247 	hdr = (struct xe_sysctrl_mailbox_msg_hdr *)buffer;
248 
249 	if (!XE_SYSCTRL_HDR_IS_RESPONSE(hdr) ||
250 	    XE_SYSCTRL_HDR_GROUP_ID(hdr) != XE_SYSCTRL_HDR_GROUP_ID(req) ||
251 	    XE_SYSCTRL_HDR_COMMAND(hdr) != XE_SYSCTRL_HDR_COMMAND(req)) {
252 		xe_err(xe, "sysctrl: Response header mismatch\n");
253 		return -EPROTO;
254 	}
255 
256 	if (XE_SYSCTRL_HDR_RESULT(hdr) != 0) {
257 		xe_err(xe, "sysctrl: Firmware error: 0x%02lx\n",
258 		       XE_SYSCTRL_HDR_RESULT(hdr));
259 		return -EIO;
260 	}
261 
262 	memcpy(data_out, hdr + 1, data_out_len);
263 	*rdata_len = out - buffer - sizeof(*hdr);
264 
265 	return 0;
266 }
267 
268 static int sysctrl_send_command(struct xe_sysctrl *sc,
269 				const u8 *mbox_cmd, size_t cmd_size,
270 				void *data_out, size_t data_out_len,
271 				size_t *rdata_len, unsigned int timeout_ms)
272 {
273 	const struct xe_sysctrl_mailbox_msg_hdr *hdr;
274 	size_t received;
275 	int ret;
276 
277 	ret = sysctrl_send_frames(sc, mbox_cmd, cmd_size, timeout_ms);
278 	if (ret)
279 		return ret;
280 
281 	if (!data_out || !rdata_len)
282 		return 0;
283 
284 	hdr = (const struct xe_sysctrl_mailbox_msg_hdr *)mbox_cmd;
285 
286 	ret = sysctrl_receive_frames(sc, hdr, data_out, data_out_len,
287 				     &received, timeout_ms);
288 	if (ret)
289 		return ret;
290 
291 	*rdata_len = received;
292 
293 	return 0;
294 }
295 
296 /**
297  * xe_sysctrl_mailbox_init - Initialize System Controller mailbox interface
298  * @sc: System controller structure
299  *
300  * Initialize system controller mailbox interface for communication.
301  */
302 void xe_sysctrl_mailbox_init(struct xe_sysctrl *sc)
303 {
304 	u32 ctrl_reg;
305 
306 	ctrl_reg = xe_mmio_read32(sc->mmio, SYSCTRL_MB_CTRL);
307 	sc->phase_bit = (ctrl_reg & SYSCTRL_FRAME_PHASE) ? 1 : 0;
308 }
309 
310 /**
311  * xe_sysctrl_send_command() - Send mailbox command to System Controller
312  * @sc: System Controller instance
313  * @cmd: Command descriptor containing request header and payload buffers
314  * @rdata_len: Pointer to store actual response data length
315  *
316  * Sends a mailbox command to System Controller firmware using
317  * System Controller mailbox and waits for a response.
318  *
319  * Request payload is provided via @cmd->data_in and @cmd->data_in_len.
320  * If a response is expected, @cmd->data_out must point to a buffer of
321  * size @cmd->data_out_len supplied by caller.
322  *
323  * On success, @rdata_len is updated with number of valid response bytes
324  * returned by firmware, bounded by @cmd->data_out_len.
325  *
326  * Return: 0 on success, or negative errno on failure.
327  */
328 int xe_sysctrl_send_command(struct xe_sysctrl *sc,
329 			    struct xe_sysctrl_mailbox_command *cmd,
330 			    size_t *rdata_len)
331 {
332 	struct xe_device *xe = sc_to_xe(sc);
333 	u8 group_id, command_code;
334 	u8 *mbox_cmd = NULL;
335 	size_t cmd_size = 0;
336 	int ret;
337 
338 	guard(xe_pm_runtime_noresume)(xe);
339 
340 	if (!xe->info.has_sysctrl)
341 		return -ENODEV;
342 
343 	xe_assert(xe, cmd->data_in || cmd->data_out);
344 	xe_assert(xe, !cmd->data_in || cmd->data_in_len);
345 	xe_assert(xe, !cmd->data_out || cmd->data_out_len);
346 
347 	group_id = XE_SYSCTRL_APP_HDR_GROUP_ID(&cmd->header);
348 	command_code = XE_SYSCTRL_APP_HDR_COMMAND(&cmd->header);
349 
350 	might_sleep();
351 
352 	ret = sysctrl_prepare_command(xe, group_id, command_code,
353 				      cmd->data_in, cmd->data_in_len,
354 				      &mbox_cmd, &cmd_size);
355 	if (ret) {
356 		xe_err(xe, "sysctrl: Failed to prepare command: %pe\n", ERR_PTR(ret));
357 		return ret;
358 	}
359 
360 	guard(mutex)(&sc->cmd_lock);
361 
362 	ret = sysctrl_send_command(sc, mbox_cmd, cmd_size,
363 				   cmd->data_out, cmd->data_out_len, rdata_len,
364 				   XE_SYSCTRL_MB_DEFAULT_TIMEOUT_MS);
365 	if (ret)
366 		xe_err(xe, "sysctrl: Mailbox command failed: %pe\n", ERR_PTR(ret));
367 
368 	kfree(mbox_cmd);
369 
370 	return ret;
371 }
372