1 files changed, 231 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_pm.c b/drivers/gpu/drm/i915/gem/i915_gem_pm.c
new file mode 100644
index 000000000..8d30db5e6
--- /dev/null
+++ b/drivers/gpu/drm/i915/gem/i915_gem_pm.c
@@ -0,0 +1,231 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include "gem/i915_gem_pm.h"
+#include "gem/i915_gem_ttm_pm.h"
+#include "gt/intel_gt.h"
+#include "gt/intel_gt_pm.h"
+#include "gt/intel_gt_requests.h"
+
+#include "i915_driver.h"
+#include "i915_drv.h"
+
+#if defined(CONFIG_X86)
+#include <asm/smp.h>
+#else
+#define wbinvd_on_all_cpus() \
+	pr_warn(DRIVER_NAME ": Missing cache flush in %s\n", __func__)
+#endif
+
+void i915_gem_suspend(struct drm_i915_private *i915)
+{
+	GEM_TRACE("%s\n", dev_name(i915->drm.dev));
+
+	intel_wakeref_auto(&i915->runtime_pm.userfault_wakeref, 0);
+	flush_workqueue(i915->wq);
+
+	/*
+	 * We have to flush all the executing contexts to main memory so
+	 * that they can saved in the hibernation image. To ensure the last
+	 * context image is coherent, we have to switch away from it. That
+	 * leaves the i915->kernel_context still active when
+	 * we actually suspend, and its image in memory may not match the GPU
+	 * state. Fortunately, the kernel_context is disposable and we do
+	 * not rely on its state.
+	 */
+	intel_gt_suspend_prepare(to_gt(i915));
+
+	i915_gem_drain_freed_objects(i915);
+}
+
+static int lmem_restore(struct drm_i915_private *i915, u32 flags)
+{
+	struct intel_memory_region *mr;
+	int ret = 0, id;
+
+	for_each_memory_region(mr, i915, id) {
+		if (mr->type == INTEL_MEMORY_LOCAL) {
+			ret = i915_ttm_restore_region(mr, flags);
+			if (ret)
+				break;
+		}
+	}
+
+	return ret;
+}
+
+static int lmem_suspend(struct drm_i915_private *i915, u32 flags)
+{
+	struct intel_memory_region *mr;
+	int ret = 0, id;
+
+	for_each_memory_region(mr, i915, id) {
+		if (mr->type == INTEL_MEMORY_LOCAL) {
+			ret = i915_ttm_backup_region(mr, flags);
+			if (ret)
+				break;
+		}
+	}
+
+	return ret;
+}
+
+static void lmem_recover(struct drm_i915_private *i915)
+{
+	struct intel_memory_region *mr;
+	int id;
+
+	for_each_memory_region(mr, i915, id)
+		if (mr->type == INTEL_MEMORY_LOCAL)
+			i915_ttm_recover_region(mr);
+}
+
+int i915_gem_backup_suspend(struct drm_i915_private *i915)
+{
+	int ret;
+
+	/* Opportunistically try to evict unpinned objects */
+	ret = lmem_suspend(i915, I915_TTM_BACKUP_ALLOW_GPU);
+	if (ret)
+		goto out_recover;
+
+	i915_gem_suspend(i915);
+
+	/*
+	 * More objects may have become unpinned as requests were
+	 * retired. Now try to evict again. The gt may be wedged here
+	 * in which case we automatically fall back to memcpy.
+	 * We allow also backing up pinned objects that have not been
+	 * marked for early recover, and that may contain, for example,
+	 * page-tables for the migrate context.
+	 */
+	ret = lmem_suspend(i915, I915_TTM_BACKUP_ALLOW_GPU |
+			   I915_TTM_BACKUP_PINNED);
+	if (ret)
+		goto out_recover;
+
+	/*
+	 * Remaining objects are backed up using memcpy once we've stopped
+	 * using the migrate context.
+	 */
+	ret = lmem_suspend(i915, I915_TTM_BACKUP_PINNED);
+	if (ret)
+		goto out_recover;
+
+	return 0;
+
+out_recover:
+	lmem_recover(i915);
+
+	return ret;
+}
+
+void i915_gem_suspend_late(struct drm_i915_private *i915)
+{
+	struct drm_i915_gem_object *obj;
+	struct list_head *phases[] = {
+		&i915->mm.shrink_list,
+		&i915->mm.purge_list,
+		NULL
+	}, **phase;
+	unsigned long flags;
+	bool flush = false;
+
+	/*
+	 * Neither the BIOS, ourselves or any other kernel
+	 * expects the system to be in execlists mode on startup,
+	 * so we need to reset the GPU back to legacy mode. And the only
+	 * known way to disable logical contexts is through a GPU reset.
+	 *
+	 * So in order to leave the system in a known default configuration,
+	 * always reset the GPU upon unload and suspend. Afterwards we then
+	 * clean up the GEM state tracking, flushing off the requests and
+	 * leaving the system in a known idle state.
+	 *
+	 * Note that is of the upmost importance that the GPU is idle and
+	 * all stray writes are flushed *before* we dismantle the backing
+	 * storage for the pinned objects.
+	 *
+	 * However, since we are uncertain that resetting the GPU on older
+	 * machines is a good idea, we don't - just in case it leaves the
+	 * machine in an unusable condition.
+	 */
+
+	intel_gt_suspend_late(to_gt(i915));
+
+	spin_lock_irqsave(&i915->mm.obj_lock, flags);
+	for (phase = phases; *phase; phase++) {
+		list_for_each_entry(obj, *phase, mm.link) {
+			if (!(obj->cache_coherent & I915_BO_CACHE_COHERENT_FOR_READ))
+				flush |= (obj->read_domains & I915_GEM_DOMAIN_CPU) == 0;
+			__start_cpu_write(obj); /* presume auto-hibernate */
+		}
+	}
+	spin_unlock_irqrestore(&i915->mm.obj_lock, flags);
+	if (flush)
+		wbinvd_on_all_cpus();
+}
+
+int i915_gem_freeze(struct drm_i915_private *i915)
+{
+	/* Discard all purgeable objects, let userspace recover those as
+	 * required after resuming.
+	 */
+	i915_gem_shrink_all(i915);
+
+	return 0;
+}
+
+int i915_gem_freeze_late(struct drm_i915_private *i915)
+{
+	struct drm_i915_gem_object *obj;
+	intel_wakeref_t wakeref;
+
+	/*
+	 * Called just before we write the hibernation image.
+	 *
+	 * We need to update the domain tracking to reflect that the CPU
+	 * will be accessing all the pages to create and restore from the
+	 * hibernation, and so upon restoration those pages will be in the
+	 * CPU domain.
+	 *
+	 * To make sure the hibernation image contains the latest state,
+	 * we update that state just before writing out the image.
+	 *
+	 * To try and reduce the hibernation image, we manually shrink
+	 * the objects as well, see i915_gem_freeze()
+	 */
+
+	with_intel_runtime_pm(&i915->runtime_pm, wakeref)
+		i915_gem_shrink(NULL, i915, -1UL, NULL, ~0);
+	i915_gem_drain_freed_objects(i915);
+
+	wbinvd_on_all_cpus();
+	list_for_each_entry(obj, &i915->mm.shrink_list, mm.link)
+		__start_cpu_write(obj);
+
+	return 0;
+}
+
+void i915_gem_resume(struct drm_i915_private *i915)
+{
+	int ret;
+
+	GEM_TRACE("%s\n", dev_name(i915->drm.dev));
+
+	ret = lmem_restore(i915, 0);
+	GEM_WARN_ON(ret);
+
+	/*
+	 * As we didn't flush the kernel context before suspend, we cannot
+	 * guarantee that the context image is complete. So let's just reset
+	 * it and start again.
+	 */
+	intel_gt_resume(to_gt(i915));
+
+	ret = lmem_restore(i915, I915_TTM_BACKUP_ALLOW_GPU);
+	GEM_WARN_ON(ret);
+}