1// SPDX-License-Identifier: GPL-2.0-only OR MIT
2/* Copyright (c) 2023 Imagination Technologies Ltd. */
3
4#include "pvr_device.h"
5#include "pvr_fw.h"
6#include "pvr_fw_startstop.h"
7#include "pvr_power.h"
8#include "pvr_queue.h"
9#include "pvr_rogue_fwif.h"
10
11#include <drm/drm_drv.h>
12#include <drm/drm_managed.h>
13#include <linux/clk.h>
14#include <linux/interrupt.h>
15#include <linux/mutex.h>
16#include <linux/platform_device.h>
17#include <linux/pm_runtime.h>
18#include <linux/timer.h>
19#include <linux/types.h>
20#include <linux/workqueue.h>
21
22#define POWER_SYNC_TIMEOUT_US (1000000) /* 1s */
23
24#define WATCHDOG_TIME_MS (500)
25
26/**
27 * pvr_device_lost() - Mark GPU device as lost
28 * @pvr_dev: Target PowerVR device.
29 *
30 * This will cause the DRM device to be unplugged.
31 */
32void
33pvr_device_lost(struct pvr_device *pvr_dev)
34{
35	if (!pvr_dev->lost) {
36		pvr_dev->lost = true;
37		drm_dev_unplug(from_pvr_device(pvr_dev));
38	}
39}
40
41static int
42pvr_power_send_command(struct pvr_device *pvr_dev, struct rogue_fwif_kccb_cmd *pow_cmd)
43{
44	struct pvr_fw_device *fw_dev = &pvr_dev->fw_dev;
45	u32 slot_nr;
46	u32 value;
47	int err;
48
49	WRITE_ONCE(*fw_dev->power_sync, 0);
50
51	err = pvr_kccb_send_cmd_powered(pvr_dev, pow_cmd, &slot_nr);
52	if (err)
53		return err;
54
55	/* Wait for FW to acknowledge. */
56	return readl_poll_timeout(pvr_dev->fw_dev.power_sync, value, value != 0, 100,
57				  POWER_SYNC_TIMEOUT_US);
58}
59
60static int
61pvr_power_request_idle(struct pvr_device *pvr_dev)
62{
63	struct rogue_fwif_kccb_cmd pow_cmd;
64
65	/* Send FORCED_IDLE request to FW. */
66	pow_cmd.cmd_type = ROGUE_FWIF_KCCB_CMD_POW;
67	pow_cmd.cmd_data.pow_data.pow_type = ROGUE_FWIF_POW_FORCED_IDLE_REQ;
68	pow_cmd.cmd_data.pow_data.power_req_data.pow_request_type = ROGUE_FWIF_POWER_FORCE_IDLE;
69
70	return pvr_power_send_command(pvr_dev, &pow_cmd);
71}
72
73static int
74pvr_power_request_pwr_off(struct pvr_device *pvr_dev)
75{
76	struct rogue_fwif_kccb_cmd pow_cmd;
77
78	/* Send POW_OFF request to firmware. */
79	pow_cmd.cmd_type = ROGUE_FWIF_KCCB_CMD_POW;
80	pow_cmd.cmd_data.pow_data.pow_type = ROGUE_FWIF_POW_OFF_REQ;
81	pow_cmd.cmd_data.pow_data.power_req_data.forced = true;
82
83	return pvr_power_send_command(pvr_dev, &pow_cmd);
84}
85
86static int
87pvr_power_fw_disable(struct pvr_device *pvr_dev, bool hard_reset)
88{
89	if (!hard_reset) {
90		int err;
91
92		cancel_delayed_work_sync(&pvr_dev->watchdog.work);
93
94		err = pvr_power_request_idle(pvr_dev);
95		if (err)
96			return err;
97
98		err = pvr_power_request_pwr_off(pvr_dev);
99		if (err)
100			return err;
101	}
102
103	return pvr_fw_stop(pvr_dev);
104}
105
106static int
107pvr_power_fw_enable(struct pvr_device *pvr_dev)
108{
109	int err;
110
111	err = pvr_fw_start(pvr_dev);
112	if (err)
113		return err;
114
115	err = pvr_wait_for_fw_boot(pvr_dev);
116	if (err) {
117		drm_err(from_pvr_device(pvr_dev), "Firmware failed to boot\n");
118		pvr_fw_stop(pvr_dev);
119		return err;
120	}
121
122	queue_delayed_work(pvr_dev->sched_wq, &pvr_dev->watchdog.work,
123			   msecs_to_jiffies(WATCHDOG_TIME_MS));
124
125	return 0;
126}
127
128bool
129pvr_power_is_idle(struct pvr_device *pvr_dev)
130{
131	/*
132	 * FW power state can be out of date if a KCCB command has been submitted but the FW hasn't
133	 * started processing it yet. So also check the KCCB status.
134	 */
135	enum rogue_fwif_pow_state pow_state = READ_ONCE(pvr_dev->fw_dev.fwif_sysdata->pow_state);
136	bool kccb_idle = pvr_kccb_is_idle(pvr_dev);
137
138	return (pow_state == ROGUE_FWIF_POW_IDLE) && kccb_idle;
139}
140
141static bool
142pvr_watchdog_kccb_stalled(struct pvr_device *pvr_dev)
143{
144	/* Check KCCB commands are progressing. */
145	u32 kccb_cmds_executed = pvr_dev->fw_dev.fwif_osdata->kccb_cmds_executed;
146	bool kccb_is_idle = pvr_kccb_is_idle(pvr_dev);
147
148	if (pvr_dev->watchdog.old_kccb_cmds_executed == kccb_cmds_executed && !kccb_is_idle) {
149		pvr_dev->watchdog.kccb_stall_count++;
150
151		/*
152		 * If we have commands pending with no progress for 2 consecutive polls then
153		 * consider KCCB command processing stalled.
154		 */
155		if (pvr_dev->watchdog.kccb_stall_count == 2) {
156			pvr_dev->watchdog.kccb_stall_count = 0;
157			return true;
158		}
159	} else if (pvr_dev->watchdog.old_kccb_cmds_executed == kccb_cmds_executed) {
160		bool has_active_contexts;
161
162		mutex_lock(&pvr_dev->queues.lock);
163		has_active_contexts = list_empty(&pvr_dev->queues.active);
164		mutex_unlock(&pvr_dev->queues.lock);
165
166		if (has_active_contexts) {
167			/* Send a HEALTH_CHECK command so we can verify FW is still alive. */
168			struct rogue_fwif_kccb_cmd health_check_cmd;
169
170			health_check_cmd.cmd_type = ROGUE_FWIF_KCCB_CMD_HEALTH_CHECK;
171
172			pvr_kccb_send_cmd_powered(pvr_dev, &health_check_cmd, NULL);
173		}
174	} else {
175		pvr_dev->watchdog.old_kccb_cmds_executed = kccb_cmds_executed;
176		pvr_dev->watchdog.kccb_stall_count = 0;
177	}
178
179	return false;
180}
181
182static void
183pvr_watchdog_worker(struct work_struct *work)
184{
185	struct pvr_device *pvr_dev = container_of(work, struct pvr_device,
186						  watchdog.work.work);
187	bool stalled;
188
189	if (pvr_dev->lost)
190		return;
191
192	if (pm_runtime_get_if_in_use(from_pvr_device(pvr_dev)->dev) <= 0)
193		goto out_requeue;
194
195	if (!pvr_dev->fw_dev.booted)
196		goto out_pm_runtime_put;
197
198	stalled = pvr_watchdog_kccb_stalled(pvr_dev);
199
200	if (stalled) {
201		drm_err(from_pvr_device(pvr_dev), "FW stalled, trying hard reset");
202
203		pvr_power_reset(pvr_dev, true);
204		/* Device may be lost at this point. */
205	}
206
207out_pm_runtime_put:
208	pm_runtime_put(from_pvr_device(pvr_dev)->dev);
209
210out_requeue:
211	if (!pvr_dev->lost) {
212		queue_delayed_work(pvr_dev->sched_wq, &pvr_dev->watchdog.work,
213				   msecs_to_jiffies(WATCHDOG_TIME_MS));
214	}
215}
216
217/**
218 * pvr_watchdog_init() - Initialise watchdog for device
219 * @pvr_dev: Target PowerVR device.
220 *
221 * Returns:
222 *  * 0 on success, or
223 *  * -%ENOMEM on out of memory.
224 */
225int
226pvr_watchdog_init(struct pvr_device *pvr_dev)
227{
228	INIT_DELAYED_WORK(&pvr_dev->watchdog.work, pvr_watchdog_worker);
229
230	return 0;
231}
232
233int
234pvr_power_device_suspend(struct device *dev)
235{
236	struct platform_device *plat_dev = to_platform_device(dev);
237	struct drm_device *drm_dev = platform_get_drvdata(plat_dev);
238	struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
239	int err = 0;
240	int idx;
241
242	if (!drm_dev_enter(drm_dev, &idx))
243		return -EIO;
244
245	if (pvr_dev->fw_dev.booted) {
246		err = pvr_power_fw_disable(pvr_dev, false);
247		if (err)
248			goto err_drm_dev_exit;
249	}
250
251	clk_disable_unprepare(pvr_dev->mem_clk);
252	clk_disable_unprepare(pvr_dev->sys_clk);
253	clk_disable_unprepare(pvr_dev->core_clk);
254
255err_drm_dev_exit:
256	drm_dev_exit(idx);
257
258	return err;
259}
260
261int
262pvr_power_device_resume(struct device *dev)
263{
264	struct platform_device *plat_dev = to_platform_device(dev);
265	struct drm_device *drm_dev = platform_get_drvdata(plat_dev);
266	struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
267	int idx;
268	int err;
269
270	if (!drm_dev_enter(drm_dev, &idx))
271		return -EIO;
272
273	err = clk_prepare_enable(pvr_dev->core_clk);
274	if (err)
275		goto err_drm_dev_exit;
276
277	err = clk_prepare_enable(pvr_dev->sys_clk);
278	if (err)
279		goto err_core_clk_disable;
280
281	err = clk_prepare_enable(pvr_dev->mem_clk);
282	if (err)
283		goto err_sys_clk_disable;
284
285	if (pvr_dev->fw_dev.booted) {
286		err = pvr_power_fw_enable(pvr_dev);
287		if (err)
288			goto err_mem_clk_disable;
289	}
290
291	drm_dev_exit(idx);
292
293	return 0;
294
295err_mem_clk_disable:
296	clk_disable_unprepare(pvr_dev->mem_clk);
297
298err_sys_clk_disable:
299	clk_disable_unprepare(pvr_dev->sys_clk);
300
301err_core_clk_disable:
302	clk_disable_unprepare(pvr_dev->core_clk);
303
304err_drm_dev_exit:
305	drm_dev_exit(idx);
306
307	return err;
308}
309
310int
311pvr_power_device_idle(struct device *dev)
312{
313	struct platform_device *plat_dev = to_platform_device(dev);
314	struct drm_device *drm_dev = platform_get_drvdata(plat_dev);
315	struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
316
317	return pvr_power_is_idle(pvr_dev) ? 0 : -EBUSY;
318}
319
320/**
321 * pvr_power_reset() - Reset the GPU
322 * @pvr_dev: Device pointer
323 * @hard_reset: %true for hard reset, %false for soft reset
324 *
325 * If @hard_reset is %false and the FW processor fails to respond during the reset process, this
326 * function will attempt a hard reset.
327 *
328 * If a hard reset fails then the GPU device is reported as lost.
329 *
330 * Returns:
331 *  * 0 on success, or
332 *  * Any error code returned by pvr_power_get, pvr_power_fw_disable or pvr_power_fw_enable().
333 */
334int
335pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
336{
337	bool queues_disabled = false;
338	int err;
339
340	/*
341	 * Take a power reference during the reset. This should prevent any interference with the
342	 * power state during reset.
343	 */
344	WARN_ON(pvr_power_get(pvr_dev));
345
346	down_write(&pvr_dev->reset_sem);
347
348	if (pvr_dev->lost) {
349		err = -EIO;
350		goto err_up_write;
351	}
352
353	/* Disable IRQs for the duration of the reset. */
354	disable_irq(pvr_dev->irq);
355
356	do {
357		if (hard_reset) {
358			pvr_queue_device_pre_reset(pvr_dev);
359			queues_disabled = true;
360		}
361
362		err = pvr_power_fw_disable(pvr_dev, hard_reset);
363		if (!err) {
364			if (hard_reset) {
365				pvr_dev->fw_dev.booted = false;
366				WARN_ON(pm_runtime_force_suspend(from_pvr_device(pvr_dev)->dev));
367
368				err = pvr_fw_hard_reset(pvr_dev);
369				if (err)
370					goto err_device_lost;
371
372				err = pm_runtime_force_resume(from_pvr_device(pvr_dev)->dev);
373				pvr_dev->fw_dev.booted = true;
374				if (err)
375					goto err_device_lost;
376			} else {
377				/* Clear the FW faulted flags. */
378				pvr_dev->fw_dev.fwif_sysdata->hwr_state_flags &=
379					~(ROGUE_FWIF_HWR_FW_FAULT |
380					  ROGUE_FWIF_HWR_RESTART_REQUESTED);
381			}
382
383			pvr_fw_irq_clear(pvr_dev);
384
385			err = pvr_power_fw_enable(pvr_dev);
386		}
387
388		if (err && hard_reset)
389			goto err_device_lost;
390
391		if (err && !hard_reset) {
392			drm_err(from_pvr_device(pvr_dev), "FW stalled, trying hard reset");
393			hard_reset = true;
394		}
395	} while (err);
396
397	if (queues_disabled)
398		pvr_queue_device_post_reset(pvr_dev);
399
400	enable_irq(pvr_dev->irq);
401
402	up_write(&pvr_dev->reset_sem);
403
404	pvr_power_put(pvr_dev);
405
406	return 0;
407
408err_device_lost:
409	drm_err(from_pvr_device(pvr_dev), "GPU device lost");
410	pvr_device_lost(pvr_dev);
411
412	/* Leave IRQs disabled if the device is lost. */
413
414	if (queues_disabled)
415		pvr_queue_device_post_reset(pvr_dev);
416
417err_up_write:
418	up_write(&pvr_dev->reset_sem);
419
420	pvr_power_put(pvr_dev);
421
422	return err;
423}
424
425/**
426 * pvr_watchdog_fini() - Shutdown watchdog for device
427 * @pvr_dev: Target PowerVR device.
428 */
429void
430pvr_watchdog_fini(struct pvr_device *pvr_dev)
431{
432	cancel_delayed_work_sync(&pvr_dev->watchdog.work);
433}
434