drm/i915/gt: Hold rpm wakeref before taking ggtt->vm.mutex

We need to hold the runtime-pm wakeref to update the global PTEs (as
they exist behind a PCI BAR). However, some systems invoke ACPI during
runtime resume and so require allocations, which is verboten inside the
vm->mutex. Ergo, we must not use intel_runtime_pm_get() inside the
mutex, but lift the call outside.

Closes: https://gitlab.freedesktop.org/drm/intel/issues/958
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Matthew Auld <matthew.auld@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200110144418.1415639-1-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/intel_ggtt.c b/drivers/gpu/drm/i915/gt/intel_ggtt.c
index c8ba38e..7909672 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_ggtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_ggtt.c
@@ -430,9 +430,7 @@ static int ggtt_bind_vma(struct i915_vma *vma,
                         enum i915_cache_level cache_level,
                         u32 flags)
 {
-       struct drm_i915_private *i915 = vma->vm->i915;
        struct drm_i915_gem_object *obj = vma->obj;
-       intel_wakeref_t wakeref;
        u32 pte_flags;
 
        /* Applicable to VLV (gen8+ do not support RO in the GGTT) */
@@ -440,8 +438,7 @@ static int ggtt_bind_vma(struct i915_vma *vma,
        if (i915_gem_object_is_readonly(obj))
                pte_flags |= PTE_READ_ONLY;
 
-       with_intel_runtime_pm(&i915->runtime_pm, wakeref)
-               vma->vm->insert_entries(vma->vm, vma, cache_level, pte_flags);
+       vma->vm->insert_entries(vma->vm, vma, cache_level, pte_flags);
 
        vma->page_sizes.gtt = I915_GTT_PAGE_SIZE;
 
@@ -457,11 +454,7 @@ static int ggtt_bind_vma(struct i915_vma *vma,
 
 static void ggtt_unbind_vma(struct i915_vma *vma)
 {
-       struct drm_i915_private *i915 = vma->vm->i915;
-       intel_wakeref_t wakeref;
-
-       with_intel_runtime_pm(&i915->runtime_pm, wakeref)
-               vma->vm->clear_range(vma->vm, vma->node.start, vma->size);
+       vma->vm->clear_range(vma->vm, vma->node.start, vma->size);
 }
 
 static int ggtt_reserve_guc_top(struct i915_ggtt *ggtt)
@@ -571,7 +564,6 @@ static int aliasing_gtt_bind_vma(struct i915_vma *vma,
                                 enum i915_cache_level cache_level,
                                 u32 flags)
 {
-       struct drm_i915_private *i915 = vma->vm->i915;
        u32 pte_flags;
        int ret;
 
@@ -599,28 +591,18 @@ static int aliasing_gtt_bind_vma(struct i915_vma *vma,
                                         cache_level, pte_flags);
        }
 
-       if (flags & I915_VMA_GLOBAL_BIND) {
-               intel_wakeref_t wakeref;
-
-               with_intel_runtime_pm(&i915->runtime_pm, wakeref) {
-                       vma->vm->insert_entries(vma->vm, vma,
-                                               cache_level, pte_flags);
-               }
-       }
+       if (flags & I915_VMA_GLOBAL_BIND)
+               vma->vm->insert_entries(vma->vm, vma, cache_level, pte_flags);
 
        return 0;
 }
 
 static void aliasing_gtt_unbind_vma(struct i915_vma *vma)
 {
-       struct drm_i915_private *i915 = vma->vm->i915;
-
        if (i915_vma_is_bound(vma, I915_VMA_GLOBAL_BIND)) {
                struct i915_address_space *vm = vma->vm;
-               intel_wakeref_t wakeref;
 
-               with_intel_runtime_pm(&i915->runtime_pm, wakeref)
-                       vm->clear_range(vm, vma->node.start, vma->size);
+               vm->clear_range(vm, vma->node.start, vma->size);
        }
 
        if (test_and_clear_bit(I915_VMA_ALLOC_BIT, __i915_vma_flags(vma))) {

diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 43d5c27..17d7c52 100644 (file)
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -858,6 +858,7 @@ static void vma_unbind_pages(struct i915_vma *vma)
 int i915_vma_pin(struct i915_vma *vma, u64 size, u64 alignment, u64 flags)
 {
        struct i915_vma_work *work = NULL;
+       intel_wakeref_t wakeref = 0;
        unsigned int bound;
        int err;
 
@@ -883,6 +884,9 @@ int i915_vma_pin(struct i915_vma *vma, u64 size, u64 alignment, u64 flags)
                }
        }
 
+       if (flags & PIN_GLOBAL)
+               wakeref = intel_runtime_pm_get(&vma->vm->i915->runtime_pm);
+
        /* No more allocations allowed once we hold vm->mutex */
        err = mutex_lock_interruptible(&vma->vm->mutex);
        if (err)
@@ -946,6 +950,8 @@ err_unlock:
 err_fence:
        if (work)
                dma_fence_work_commit(&work->base);
+       if (wakeref)
+               intel_runtime_pm_put(&vma->vm->i915->runtime_pm, wakeref);
 err_pages:
        vma_put_pages(vma);
        return err;
@@ -1246,11 +1252,16 @@ int __i915_vma_unbind(struct i915_vma *vma)
 int i915_vma_unbind(struct i915_vma *vma)
 {
        struct i915_address_space *vm = vma->vm;
+       intel_wakeref_t wakeref = 0;
        int err;
 
        if (!drm_mm_node_allocated(&vma->node))
                return 0;
 
+       if (i915_vma_is_bound(vma, I915_VMA_GLOBAL_BIND))
+               /* XXX not always required: nop_clear_range */
+               wakeref = intel_runtime_pm_get(&vm->i915->runtime_pm);
+
        err = mutex_lock_interruptible(&vm->mutex);
        if (err)
                return err;
@@ -1258,6 +1269,9 @@ int i915_vma_unbind(struct i915_vma *vma)
        err = __i915_vma_unbind(vma);
        mutex_unlock(&vm->mutex);
 
+       if (wakeref)
+               intel_runtime_pm_put(&vm->i915->runtime_pm, wakeref);
+
        return err;
 }