1 files changed, 433 insertions, 0 deletions
diff --git a/drivers/gpu/drm/imagination/pvr_power.c b/drivers/gpu/drm/imagination/pvr_power.c
new file mode 100644
index 000000000000..ba7816fd28ec
--- /dev/null
+++ b/drivers/gpu/drm/imagination/pvr_power.c
@@ -0,0 +1,433 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/* Copyright (c) 2023 Imagination Technologies Ltd. */
+
+#include "pvr_device.h"
+#include "pvr_fw.h"
+#include "pvr_fw_startstop.h"
+#include "pvr_power.h"
+#include "pvr_queue.h"
+#include "pvr_rogue_fwif.h"
+
+#include <drm/drm_drv.h>
+#include <drm/drm_managed.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/timer.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#define POWER_SYNC_TIMEOUT_US (1000000) /* 1s */
+
+#define WATCHDOG_TIME_MS (500)
+
+/**
+ * pvr_device_lost() - Mark GPU device as lost
+ * @pvr_dev: Target PowerVR device.
+ *
+ * This will cause the DRM device to be unplugged.
+ */
+void
+pvr_device_lost(struct pvr_device *pvr_dev)
+{
+	if (!pvr_dev->lost) {
+		pvr_dev->lost = true;
+		drm_dev_unplug(from_pvr_device(pvr_dev));
+	}
+}
+
+static int
+pvr_power_send_command(struct pvr_device *pvr_dev, struct rogue_fwif_kccb_cmd *pow_cmd)
+{
+	struct pvr_fw_device *fw_dev = &pvr_dev->fw_dev;
+	u32 slot_nr;
+	u32 value;
+	int err;
+
+	WRITE_ONCE(*fw_dev->power_sync, 0);
+
+	err = pvr_kccb_send_cmd_powered(pvr_dev, pow_cmd, &slot_nr);
+	if (err)
+		return err;
+
+	/* Wait for FW to acknowledge. */
+	return readl_poll_timeout(pvr_dev->fw_dev.power_sync, value, value != 0, 100,
+				  POWER_SYNC_TIMEOUT_US);
+}
+
+static int
+pvr_power_request_idle(struct pvr_device *pvr_dev)
+{
+	struct rogue_fwif_kccb_cmd pow_cmd;
+
+	/* Send FORCED_IDLE request to FW. */
+	pow_cmd.cmd_type = ROGUE_FWIF_KCCB_CMD_POW;
+	pow_cmd.cmd_data.pow_data.pow_type = ROGUE_FWIF_POW_FORCED_IDLE_REQ;
+	pow_cmd.cmd_data.pow_data.power_req_data.pow_request_type = ROGUE_FWIF_POWER_FORCE_IDLE;
+
+	return pvr_power_send_command(pvr_dev, &pow_cmd);
+}
+
+static int
+pvr_power_request_pwr_off(struct pvr_device *pvr_dev)
+{
+	struct rogue_fwif_kccb_cmd pow_cmd;
+
+	/* Send POW_OFF request to firmware. */
+	pow_cmd.cmd_type = ROGUE_FWIF_KCCB_CMD_POW;
+	pow_cmd.cmd_data.pow_data.pow_type = ROGUE_FWIF_POW_OFF_REQ;
+	pow_cmd.cmd_data.pow_data.power_req_data.forced = true;
+
+	return pvr_power_send_command(pvr_dev, &pow_cmd);
+}
+
+static int
+pvr_power_fw_disable(struct pvr_device *pvr_dev, bool hard_reset)
+{
+	if (!hard_reset) {
+		int err;
+
+		cancel_delayed_work_sync(&pvr_dev->watchdog.work);
+
+		err = pvr_power_request_idle(pvr_dev);
+		if (err)
+			return err;
+
+		err = pvr_power_request_pwr_off(pvr_dev);
+		if (err)
+			return err;
+	}
+
+	return pvr_fw_stop(pvr_dev);
+}
+
+static int
+pvr_power_fw_enable(struct pvr_device *pvr_dev)
+{
+	int err;
+
+	err = pvr_fw_start(pvr_dev);
+	if (err)
+		return err;
+
+	err = pvr_wait_for_fw_boot(pvr_dev);
+	if (err) {
+		drm_err(from_pvr_device(pvr_dev), "Firmware failed to boot\n");
+		pvr_fw_stop(pvr_dev);
+		return err;
+	}
+
+	queue_delayed_work(pvr_dev->sched_wq, &pvr_dev->watchdog.work,
+			   msecs_to_jiffies(WATCHDOG_TIME_MS));
+
+	return 0;
+}
+
+bool
+pvr_power_is_idle(struct pvr_device *pvr_dev)
+{
+	/*
+	 * FW power state can be out of date if a KCCB command has been submitted but the FW hasn't
+	 * started processing it yet. So also check the KCCB status.
+	 */
+	enum rogue_fwif_pow_state pow_state = READ_ONCE(pvr_dev->fw_dev.fwif_sysdata->pow_state);
+	bool kccb_idle = pvr_kccb_is_idle(pvr_dev);
+
+	return (pow_state == ROGUE_FWIF_POW_IDLE) && kccb_idle;
+}
+
+static bool
+pvr_watchdog_kccb_stalled(struct pvr_device *pvr_dev)
+{
+	/* Check KCCB commands are progressing. */
+	u32 kccb_cmds_executed = pvr_dev->fw_dev.fwif_osdata->kccb_cmds_executed;
+	bool kccb_is_idle = pvr_kccb_is_idle(pvr_dev);
+
+	if (pvr_dev->watchdog.old_kccb_cmds_executed == kccb_cmds_executed && !kccb_is_idle) {
+		pvr_dev->watchdog.kccb_stall_count++;
+
+		/*
+		 * If we have commands pending with no progress for 2 consecutive polls then
+		 * consider KCCB command processing stalled.
+		 */
+		if (pvr_dev->watchdog.kccb_stall_count == 2) {
+			pvr_dev->watchdog.kccb_stall_count = 0;
+			return true;
+		}
+	} else if (pvr_dev->watchdog.old_kccb_cmds_executed == kccb_cmds_executed) {
+		bool has_active_contexts;
+
+		mutex_lock(&pvr_dev->queues.lock);
+		has_active_contexts = list_empty(&pvr_dev->queues.active);
+		mutex_unlock(&pvr_dev->queues.lock);
+
+		if (has_active_contexts) {
+			/* Send a HEALTH_CHECK command so we can verify FW is still alive. */
+			struct rogue_fwif_kccb_cmd health_check_cmd;
+
+			health_check_cmd.cmd_type = ROGUE_FWIF_KCCB_CMD_HEALTH_CHECK;
+
+			pvr_kccb_send_cmd_powered(pvr_dev, &health_check_cmd, NULL);
+		}
+	} else {
+		pvr_dev->watchdog.old_kccb_cmds_executed = kccb_cmds_executed;
+		pvr_dev->watchdog.kccb_stall_count = 0;
+	}
+
+	return false;
+}
+
+static void
+pvr_watchdog_worker(struct work_struct *work)
+{
+	struct pvr_device *pvr_dev = container_of(work, struct pvr_device,
+						  watchdog.work.work);
+	bool stalled;
+
+	if (pvr_dev->lost)
+		return;
+
+	if (pm_runtime_get_if_in_use(from_pvr_device(pvr_dev)->dev) <= 0)
+		goto out_requeue;
+
+	if (!pvr_dev->fw_dev.booted)
+		goto out_pm_runtime_put;
+
+	stalled = pvr_watchdog_kccb_stalled(pvr_dev);
+
+	if (stalled) {
+		drm_err(from_pvr_device(pvr_dev), "FW stalled, trying hard reset");
+
+		pvr_power_reset(pvr_dev, true);
+		/* Device may be lost at this point. */
+	}
+
+out_pm_runtime_put:
+	pm_runtime_put(from_pvr_device(pvr_dev)->dev);
+
+out_requeue:
+	if (!pvr_dev->lost) {
+		queue_delayed_work(pvr_dev->sched_wq, &pvr_dev->watchdog.work,
+				   msecs_to_jiffies(WATCHDOG_TIME_MS));
+	}
+}
+
+/**
+ * pvr_watchdog_init() - Initialise watchdog for device
+ * @pvr_dev: Target PowerVR device.
+ *
+ * Returns:
+ *  * 0 on success, or
+ *  * -%ENOMEM on out of memory.
+ */
+int
+pvr_watchdog_init(struct pvr_device *pvr_dev)
+{
+	INIT_DELAYED_WORK(&pvr_dev->watchdog.work, pvr_watchdog_worker);
+
+	return 0;
+}
+
+int
+pvr_power_device_suspend(struct device *dev)
+{
+	struct platform_device *plat_dev = to_platform_device(dev);
+	struct drm_device *drm_dev = platform_get_drvdata(plat_dev);
+	struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
+	int err = 0;
+	int idx;
+
+	if (!drm_dev_enter(drm_dev, &idx))
+		return -EIO;
+
+	if (pvr_dev->fw_dev.booted) {
+		err = pvr_power_fw_disable(pvr_dev, false);
+		if (err)
+			goto err_drm_dev_exit;
+	}
+
+	clk_disable_unprepare(pvr_dev->mem_clk);
+	clk_disable_unprepare(pvr_dev->sys_clk);
+	clk_disable_unprepare(pvr_dev->core_clk);
+
+err_drm_dev_exit:
+	drm_dev_exit(idx);
+
+	return err;
+}
+
+int
+pvr_power_device_resume(struct device *dev)
+{
+	struct platform_device *plat_dev = to_platform_device(dev);
+	struct drm_device *drm_dev = platform_get_drvdata(plat_dev);
+	struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
+	int idx;
+	int err;
+
+	if (!drm_dev_enter(drm_dev, &idx))
+		return -EIO;
+
+	err = clk_prepare_enable(pvr_dev->core_clk);
+	if (err)
+		goto err_drm_dev_exit;
+
+	err = clk_prepare_enable(pvr_dev->sys_clk);
+	if (err)
+		goto err_core_clk_disable;
+
+	err = clk_prepare_enable(pvr_dev->mem_clk);
+	if (err)
+		goto err_sys_clk_disable;
+
+	if (pvr_dev->fw_dev.booted) {
+		err = pvr_power_fw_enable(pvr_dev);
+		if (err)
+			goto err_mem_clk_disable;
+	}
+
+	drm_dev_exit(idx);
+
+	return 0;
+
+err_mem_clk_disable:
+	clk_disable_unprepare(pvr_dev->mem_clk);
+
+err_sys_clk_disable:
+	clk_disable_unprepare(pvr_dev->sys_clk);
+
+err_core_clk_disable:
+	clk_disable_unprepare(pvr_dev->core_clk);
+
+err_drm_dev_exit:
+	drm_dev_exit(idx);
+
+	return err;
+}
+
+int
+pvr_power_device_idle(struct device *dev)
+{
+	struct platform_device *plat_dev = to_platform_device(dev);
+	struct drm_device *drm_dev = platform_get_drvdata(plat_dev);
+	struct pvr_device *pvr_dev = to_pvr_device(drm_dev);
+
+	return pvr_power_is_idle(pvr_dev) ? 0 : -EBUSY;
+}
+
+/**
+ * pvr_power_reset() - Reset the GPU
+ * @pvr_dev: Device pointer
+ * @hard_reset: %true for hard reset, %false for soft reset
+ *
+ * If @hard_reset is %false and the FW processor fails to respond during the reset process, this
+ * function will attempt a hard reset.
+ *
+ * If a hard reset fails then the GPU device is reported as lost.
+ *
+ * Returns:
+ *  * 0 on success, or
+ *  * Any error code returned by pvr_power_get, pvr_power_fw_disable or pvr_power_fw_enable().
+ */
+int
+pvr_power_reset(struct pvr_device *pvr_dev, bool hard_reset)
+{
+	bool queues_disabled = false;
+	int err;
+
+	/*
+	 * Take a power reference during the reset. This should prevent any interference with the
+	 * power state during reset.
+	 */
+	WARN_ON(pvr_power_get(pvr_dev));
+
+	down_write(&pvr_dev->reset_sem);
+
+	if (pvr_dev->lost) {
+		err = -EIO;
+		goto err_up_write;
+	}
+
+	/* Disable IRQs for the duration of the reset. */
+	disable_irq(pvr_dev->irq);
+
+	do {
+		if (hard_reset) {
+			pvr_queue_device_pre_reset(pvr_dev);
+			queues_disabled = true;
+		}
+
+		err = pvr_power_fw_disable(pvr_dev, hard_reset);
+		if (!err) {
+			if (hard_reset) {
+				pvr_dev->fw_dev.booted = false;
+				WARN_ON(pm_runtime_force_suspend(from_pvr_device(pvr_dev)->dev));
+
+				err = pvr_fw_hard_reset(pvr_dev);
+				if (err)
+					goto err_device_lost;
+
+				err = pm_runtime_force_resume(from_pvr_device(pvr_dev)->dev);
+				pvr_dev->fw_dev.booted = true;
+				if (err)
+					goto err_device_lost;
+			} else {
+				/* Clear the FW faulted flags. */
+				pvr_dev->fw_dev.fwif_sysdata->hwr_state_flags &=
+					~(ROGUE_FWIF_HWR_FW_FAULT |
+					  ROGUE_FWIF_HWR_RESTART_REQUESTED);
+			}
+
+			pvr_fw_irq_clear(pvr_dev);
+
+			err = pvr_power_fw_enable(pvr_dev);
+		}
+
+		if (err && hard_reset)
+			goto err_device_lost;
+
+		if (err && !hard_reset) {
+			drm_err(from_pvr_device(pvr_dev), "FW stalled, trying hard reset");
+			hard_reset = true;
+		}
+	} while (err);
+
+	if (queues_disabled)
+		pvr_queue_device_post_reset(pvr_dev);
+
+	enable_irq(pvr_dev->irq);
+
+	up_write(&pvr_dev->reset_sem);
+
+	pvr_power_put(pvr_dev);
+
+	return 0;
+
+err_device_lost:
+	drm_err(from_pvr_device(pvr_dev), "GPU device lost");
+	pvr_device_lost(pvr_dev);
+
+	/* Leave IRQs disabled if the device is lost. */
+
+	if (queues_disabled)
+		pvr_queue_device_post_reset(pvr_dev);
+
+err_up_write:
+	up_write(&pvr_dev->reset_sem);
+
+	pvr_power_put(pvr_dev);
+
+	return err;
+}
+
+/**
+ * pvr_watchdog_fini() - Shutdown watchdog for device
+ * @pvr_dev: Target PowerVR device.
+ */
+void
+pvr_watchdog_fini(struct pvr_device *pvr_dev)
+{
+	cancel_delayed_work_sync(&pvr_dev->watchdog.work);
+}