/*
* 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)
{
struct intel_gt *gt;
unsigned int i;
GEM_TRACE("%s\n", dev_name(i915->drm.dev));
intel_wakeref_auto(&i915->runtime_pm.userfault_wakeref, 0);
/*
* On rare occasions, we've observed the fence completion triggers
* free_engines asynchronously via rcu_call. Ensure those are done.
* This path is only called on suspend, so it's an acceptable cost.
*/
rcu_barrier();
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.
*/
for_each_gt(gt, i915, i)
intel_gt_suspend_prepare(gt);
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;
struct intel_gt *gt;
unsigned long flags;
unsigned int i;
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.
*/
/* Like i915_gem_suspend, flush tasks staged from fence triggers */
rcu_barrier();
for_each_gt(gt, i915, i)
intel_gt_suspend_late(gt);
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)
{
struct intel_gt *gt;
int ret, i, j;
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.
*/
for_each_gt(gt, i915, i)
if (intel_gt_resume(gt))
goto err_wedged;
ret = lmem_restore(i915, I915_TTM_BACKUP_ALLOW_GPU);
GEM_WARN_ON(ret);
return;
err_wedged:
for_each_gt(gt, i915, j) {
if (!intel_gt_is_wedged(gt)) {
dev_err(i915->drm.dev,
"Failed to re-initialize GPU[%u], declaring it wedged!\n",
j);
intel_gt_set_wedged(gt);
}
if (j == i)
break;
}
}
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