1 files changed, 405 insertions, 0 deletions
diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
new file mode 100644
index 000000000000..b429c2876a76
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_pm.c
@@ -0,0 +1,405 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include "xe_pm.h"
+
+#include <linux/pm_runtime.h>
+
+#include <drm/drm_managed.h>
+#include <drm/ttm/ttm_placement.h>
+
+#include "xe_bo.h"
+#include "xe_bo_evict.h"
+#include "xe_device.h"
+#include "xe_device_sysfs.h"
+#include "xe_display.h"
+#include "xe_ggtt.h"
+#include "xe_gt.h"
+#include "xe_guc.h"
+#include "xe_irq.h"
+#include "xe_pcode.h"
+#include "xe_wa.h"
+
+/**
+ * DOC: Xe Power Management
+ *
+ * Xe PM shall be guided by the simplicity.
+ * Use the simplest hook options whenever possible.
+ * Let's not reinvent the runtime_pm references and hooks.
+ * Shall have a clear separation of display and gt underneath this component.
+ *
+ * What's next:
+ *
+ * For now s2idle and s3 are only working in integrated devices. The next step
+ * is to iterate through all VRAM's BO backing them up into the system memory
+ * before allowing the system suspend.
+ *
+ * Also runtime_pm needs to be here from the beginning.
+ *
+ * RC6/RPS are also critical PM features. Let's start with GuCRC and GuC SLPC
+ * and no wait boost. Frequency optimizations should come on a next stage.
+ */
+
+/**
+ * xe_pm_suspend - Helper for System suspend, i.e. S0->S3 / S0->S2idle
+ * @xe: xe device instance
+ *
+ * Return: 0 on success
+ */
+int xe_pm_suspend(struct xe_device *xe)
+{
+	struct xe_gt *gt;
+	u8 id;
+	int err;
+
+	for_each_gt(gt, xe, id)
+		xe_gt_suspend_prepare(gt);
+
+	/* FIXME: Super racey... */
+	err = xe_bo_evict_all(xe);
+	if (err)
+		return err;
+
+	xe_display_pm_suspend(xe);
+
+	for_each_gt(gt, xe, id) {
+		err = xe_gt_suspend(gt);
+		if (err) {
+			xe_display_pm_resume(xe);
+			return err;
+		}
+	}
+
+	xe_irq_suspend(xe);
+
+	xe_display_pm_suspend_late(xe);
+
+	return 0;
+}
+
+/**
+ * xe_pm_resume - Helper for System resume S3->S0 / S2idle->S0
+ * @xe: xe device instance
+ *
+ * Return: 0 on success
+ */
+int xe_pm_resume(struct xe_device *xe)
+{
+	struct xe_tile *tile;
+	struct xe_gt *gt;
+	u8 id;
+	int err;
+
+	for_each_tile(tile, xe, id)
+		xe_wa_apply_tile_workarounds(tile);
+
+	for_each_gt(gt, xe, id) {
+		err = xe_pcode_init(gt);
+		if (err)
+			return err;
+	}
+
+	xe_display_pm_resume_early(xe);
+
+	/*
+	 * This only restores pinned memory which is the memory required for the
+	 * GT(s) to resume.
+	 */
+	err = xe_bo_restore_kernel(xe);
+	if (err)
+		return err;
+
+	xe_irq_resume(xe);
+
+	xe_display_pm_resume(xe);
+
+	for_each_gt(gt, xe, id)
+		xe_gt_resume(gt);
+
+	err = xe_bo_restore_user(xe);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+static bool xe_pm_pci_d3cold_capable(struct pci_dev *pdev)
+{
+	struct pci_dev *root_pdev;
+
+	root_pdev = pcie_find_root_port(pdev);
+	if (!root_pdev)
+		return false;
+
+	/* D3Cold requires PME capability and _PR3 power resource */
+	if (!pci_pme_capable(root_pdev, PCI_D3cold) || !pci_pr3_present(root_pdev))
+		return false;
+
+	return true;
+}
+
+static void xe_pm_runtime_init(struct xe_device *xe)
+{
+	struct device *dev = xe->drm.dev;
+
+	/*
+	 * Disable the system suspend direct complete optimization.
+	 * We need to ensure that the regular device suspend/resume functions
+	 * are called since our runtime_pm cannot guarantee local memory
+	 * eviction for d3cold.
+	 * TODO: Check HDA audio dependencies claimed by i915, and then enforce
+	 *       this option to integrated graphics as well.
+	 */
+	if (IS_DGFX(xe))
+		dev_pm_set_driver_flags(dev, DPM_FLAG_NO_DIRECT_COMPLETE);
+
+	pm_runtime_use_autosuspend(dev);
+	pm_runtime_set_autosuspend_delay(dev, 1000);
+	pm_runtime_set_active(dev);
+	pm_runtime_allow(dev);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put(dev);
+}
+
+void xe_pm_init(struct xe_device *xe)
+{
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+
+	/* For now suspend/resume is only allowed with GuC */
+	if (!xe_device_uc_enabled(xe))
+		return;
+
+	drmm_mutex_init(&xe->drm, &xe->d3cold.lock);
+
+	xe->d3cold.capable = xe_pm_pci_d3cold_capable(pdev);
+
+	if (xe->d3cold.capable) {
+		xe_device_sysfs_init(xe);
+		xe_pm_set_vram_threshold(xe, DEFAULT_VRAM_THRESHOLD);
+	}
+
+	xe_pm_runtime_init(xe);
+}
+
+void xe_pm_runtime_fini(struct xe_device *xe)
+{
+	struct device *dev = xe->drm.dev;
+
+	pm_runtime_get_sync(dev);
+	pm_runtime_forbid(dev);
+}
+
+static void xe_pm_write_callback_task(struct xe_device *xe,
+				      struct task_struct *task)
+{
+	WRITE_ONCE(xe->pm_callback_task, task);
+
+	/*
+	 * Just in case it's somehow possible for our writes to be reordered to
+	 * the extent that something else re-uses the task written in
+	 * pm_callback_task. For example after returning from the callback, but
+	 * before the reordered write that resets pm_callback_task back to NULL.
+	 */
+	smp_mb(); /* pairs with xe_pm_read_callback_task */
+}
+
+struct task_struct *xe_pm_read_callback_task(struct xe_device *xe)
+{
+	smp_mb(); /* pairs with xe_pm_write_callback_task */
+
+	return READ_ONCE(xe->pm_callback_task);
+}
+
+int xe_pm_runtime_suspend(struct xe_device *xe)
+{
+	struct xe_gt *gt;
+	u8 id;
+	int err = 0;
+
+	if (xe->d3cold.allowed && xe_device_mem_access_ongoing(xe))
+		return -EBUSY;
+
+	/* Disable access_ongoing asserts and prevent recursive pm calls */
+	xe_pm_write_callback_task(xe, current);
+
+	/*
+	 * The actual xe_device_mem_access_put() is always async underneath, so
+	 * exactly where that is called should makes no difference to us. However
+	 * we still need to be very careful with the locks that this callback
+	 * acquires and the locks that are acquired and held by any callers of
+	 * xe_device_mem_access_get(). We already have the matching annotation
+	 * on that side, but we also need it here. For example lockdep should be
+	 * able to tell us if the following scenario is in theory possible:
+	 *
+	 * CPU0                          | CPU1 (kworker)
+	 * lock(A)                       |
+	 *                               | xe_pm_runtime_suspend()
+	 *                               |      lock(A)
+	 * xe_device_mem_access_get()    |
+	 *
+	 * This will clearly deadlock since rpm core needs to wait for
+	 * xe_pm_runtime_suspend() to complete, but here we are holding lock(A)
+	 * on CPU0 which prevents CPU1 making forward progress.  With the
+	 * annotation here and in xe_device_mem_access_get() lockdep will see
+	 * the potential lock inversion and give us a nice splat.
+	 */
+	lock_map_acquire(&xe_device_mem_access_lockdep_map);
+
+	if (xe->d3cold.allowed) {
+		err = xe_bo_evict_all(xe);
+		if (err)
+			goto out;
+	}
+
+	for_each_gt(gt, xe, id) {
+		err = xe_gt_suspend(gt);
+		if (err)
+			goto out;
+	}
+
+	xe_irq_suspend(xe);
+out:
+	lock_map_release(&xe_device_mem_access_lockdep_map);
+	xe_pm_write_callback_task(xe, NULL);
+	return err;
+}
+
+int xe_pm_runtime_resume(struct xe_device *xe)
+{
+	struct xe_gt *gt;
+	u8 id;
+	int err = 0;
+
+	/* Disable access_ongoing asserts and prevent recursive pm calls */
+	xe_pm_write_callback_task(xe, current);
+
+	lock_map_acquire(&xe_device_mem_access_lockdep_map);
+
+	/*
+	 * It can be possible that xe has allowed d3cold but other pcie devices
+	 * in gfx card soc would have blocked d3cold, therefore card has not
+	 * really lost power. Detecting primary Gt power is sufficient.
+	 */
+	gt = xe_device_get_gt(xe, 0);
+	xe->d3cold.power_lost = xe_guc_in_reset(&gt->uc.guc);
+
+	if (xe->d3cold.allowed && xe->d3cold.power_lost) {
+		for_each_gt(gt, xe, id) {
+			err = xe_pcode_init(gt);
+			if (err)
+				goto out;
+		}
+
+		/*
+		 * This only restores pinned memory which is the memory
+		 * required for the GT(s) to resume.
+		 */
+		err = xe_bo_restore_kernel(xe);
+		if (err)
+			goto out;
+	}
+
+	xe_irq_resume(xe);
+
+	for_each_gt(gt, xe, id)
+		xe_gt_resume(gt);
+
+	if (xe->d3cold.allowed && xe->d3cold.power_lost) {
+		err = xe_bo_restore_user(xe);
+		if (err)
+			goto out;
+	}
+out:
+	lock_map_release(&xe_device_mem_access_lockdep_map);
+	xe_pm_write_callback_task(xe, NULL);
+	return err;
+}
+
+int xe_pm_runtime_get(struct xe_device *xe)
+{
+	return pm_runtime_get_sync(xe->drm.dev);
+}
+
+int xe_pm_runtime_put(struct xe_device *xe)
+{
+	pm_runtime_mark_last_busy(xe->drm.dev);
+	return pm_runtime_put(xe->drm.dev);
+}
+
+int xe_pm_runtime_get_if_active(struct xe_device *xe)
+{
+	return pm_runtime_get_if_active(xe->drm.dev, true);
+}
+
+void xe_pm_assert_unbounded_bridge(struct xe_device *xe)
+{
+	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
+	struct pci_dev *bridge = pci_upstream_bridge(pdev);
+
+	if (!bridge)
+		return;
+
+	if (!bridge->driver) {
+		drm_warn(&xe->drm, "unbounded parent pci bridge, device won't support any PM support.\n");
+		device_set_pm_not_required(&pdev->dev);
+	}
+}
+
+int xe_pm_set_vram_threshold(struct xe_device *xe, u32 threshold)
+{
+	struct ttm_resource_manager *man;
+	u32 vram_total_mb = 0;
+	int i;
+
+	for (i = XE_PL_VRAM0; i <= XE_PL_VRAM1; ++i) {
+		man = ttm_manager_type(&xe->ttm, i);
+		if (man)
+			vram_total_mb += DIV_ROUND_UP_ULL(man->size, 1024 * 1024);
+	}
+
+	drm_dbg(&xe->drm, "Total vram %u mb\n", vram_total_mb);
+
+	if (threshold > vram_total_mb)
+		return -EINVAL;
+
+	mutex_lock(&xe->d3cold.lock);
+	xe->d3cold.vram_threshold = threshold;
+	mutex_unlock(&xe->d3cold.lock);
+
+	return 0;
+}
+
+void xe_pm_d3cold_allowed_toggle(struct xe_device *xe)
+{
+	struct ttm_resource_manager *man;
+	u32 total_vram_used_mb = 0;
+	u64 vram_used;
+	int i;
+
+	if (!xe->d3cold.capable) {
+		xe->d3cold.allowed = false;
+		return;
+	}
+
+	for (i = XE_PL_VRAM0; i <= XE_PL_VRAM1; ++i) {
+		man = ttm_manager_type(&xe->ttm, i);
+		if (man) {
+			vram_used = ttm_resource_manager_usage(man);
+			total_vram_used_mb += DIV_ROUND_UP_ULL(vram_used, 1024 * 1024);
+		}
+	}
+
+	mutex_lock(&xe->d3cold.lock);
+
+	if (total_vram_used_mb < xe->d3cold.vram_threshold)
+		xe->d3cold.allowed = true;
+	else
+		xe->d3cold.allowed = false;
+
+	mutex_unlock(&xe->d3cold.lock);
+
+	drm_dbg(&xe->drm,
+		"d3cold: allowed=%s\n", str_yes_no(xe->d3cold.allowed));
+}