[Intel-gfx] [PATCH] drm/i915: Split out GTT fault handler to make it generic
Abdiel Janulgue
abdiel.janulgue at linux.intel.com
Tue Jun 4 10:37:23 UTC 2019
Allow reuse of the fault-handling code in preparation for having
multiple fault handlers depending on the mmaping type and backing
storage.
Cc: Matthew Auld <matthew.auld at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Signed-off-by: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
---
drivers/gpu/drm/i915/gem/i915_gem_mman.c | 208 ++++++++++++++---------
1 file changed, 132 insertions(+), 76 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index c7b9b34de01b..ed20fab66d2f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -197,6 +197,133 @@ compute_partial_view(const struct drm_i915_gem_object *obj,
return view;
}
+struct gem_object_fault {
+ struct drm_i915_gem_object *obj;
+ pgoff_t page_offset;
+ intel_wakeref_t wakeref;
+ int srcu;
+ bool pin_vma;
+ vm_fault_t error_ret;
+};
+
+static vm_fault_t __vm_fault_from_error(struct drm_i915_private *i915,
+ int fault_ret)
+{
+ switch (fault_ret) {
+ case -EIO:
+ /*
+ * We eat errors when the gpu is terminally wedged to avoid
+ * userspace unduly crashing (gl has no provisions for mmaps to
+ * fail). But any other -EIO isn't ours (e.g. swap in failure)
+ * and so needs to be reported.
+ */
+ if (!i915_terminally_wedged(i915))
+ return VM_FAULT_SIGBUS;
+ /* else: fall through */
+ case -EAGAIN:
+ /*
+ * EAGAIN means the gpu is hung and we'll wait for the error
+ * handler to reset everything when re-faulting in
+ * i915_mutex_lock_interruptible.
+ */
+ case 0:
+ case -ERESTARTSYS:
+ case -EINTR:
+ case -EBUSY:
+ /*
+ * EBUSY is ok: this just means that another thread
+ * already did the job.
+ */
+ return VM_FAULT_NOPAGE;
+ case -ENOMEM:
+ return VM_FAULT_OOM;
+ case -ENOSPC:
+ case -EFAULT:
+ return VM_FAULT_SIGBUS;
+ default:
+ WARN_ONCE(fault_ret, "unhandled error in %s: %i\n", __func__,
+ fault_ret);
+ return VM_FAULT_SIGBUS;
+ }
+}
+
+static int __prepare_object_fault(struct vm_fault *vmf,
+ bool pin_vma,
+ struct gem_object_fault *f)
+{
+ struct vm_area_struct *area = vmf->vma;
+ struct drm_i915_gem_object *obj = to_intel_bo(area->vm_private_data);
+ struct drm_device *dev = obj->base.dev;
+ struct drm_i915_private *dev_priv = to_i915(dev);
+ bool write = area->vm_flags & VM_WRITE;
+ int ret;
+
+ /* Sanity check that we allow writing into this object */
+ if (i915_gem_object_is_readonly(obj) && write) {
+ f->error_ret = VM_FAULT_SIGBUS;
+ return -EACCES;
+ }
+
+ f->obj = obj;
+ /* We don't use vmf->pgoff since that has the fake offset */
+ f->page_offset = (vmf->address - area->vm_start) >> PAGE_SHIFT;
+
+ trace_i915_gem_object_fault(obj, f->page_offset, true, write);
+
+ ret = i915_gem_object_pin_pages(obj);
+ if (ret)
+ goto err;
+
+ f->wakeref = intel_runtime_pm_get(dev_priv);
+
+ f->srcu = i915_reset_trylock(dev_priv);
+ if (f->srcu < 0) {
+ ret = f->srcu;
+ goto err_rpm;
+ }
+
+ f->pin_vma = pin_vma;
+ if (f->pin_vma) {
+ ret = i915_mutex_lock_interruptible(dev);
+ if (ret)
+ goto err_reset;
+ }
+
+ /* Access to snoopable pages through the GTT is incoherent. */
+ if (obj->cache_level != I915_CACHE_NONE && !HAS_LLC(dev_priv)) {
+ ret = -EFAULT;
+ goto err_unlock;
+ }
+
+ return 0;
+
+err_unlock:
+ if (f->pin_vma)
+ mutex_unlock(&dev->struct_mutex);
+err_reset:
+ i915_reset_unlock(dev_priv, f->srcu);
+err_rpm:
+ intel_runtime_pm_put(dev_priv, f->wakeref);
+ i915_gem_object_unpin_pages(obj);
+err:
+ f->error_ret = __vm_fault_from_error(dev_priv, ret);
+ return ret;
+}
+
+static vm_fault_t __object_fault_fini(int fault_ret, struct gem_object_fault *f)
+{
+ struct drm_device *dev = f->obj->base.dev;
+ struct drm_i915_private *dev_priv = to_i915(dev);
+
+ if (f->pin_vma)
+ mutex_unlock(&dev->struct_mutex);
+ i915_reset_unlock(dev_priv, f->srcu);
+ intel_runtime_pm_put(dev_priv, f->wakeref);
+ i915_gem_object_unpin_pages(f->obj);
+
+ return __vm_fault_from_error(dev_priv, fault_ret);
+}
+
/**
* i915_gem_fault - fault a page into the GTT
* @vmf: fault info
@@ -223,43 +350,13 @@ vm_fault_t i915_gem_fault(struct vm_fault *vmf)
struct drm_device *dev = obj->base.dev;
struct drm_i915_private *i915 = to_i915(dev);
struct i915_ggtt *ggtt = &i915->ggtt;
- bool write = area->vm_flags & VM_WRITE;
- intel_wakeref_t wakeref;
struct i915_vma *vma;
pgoff_t page_offset;
- int srcu;
+ struct gem_object_fault fault;
int ret;
- /* Sanity check that we allow writing into this object */
- if (i915_gem_object_is_readonly(obj) && write)
- return VM_FAULT_SIGBUS;
-
- /* We don't use vmf->pgoff since that has the fake offset */
- page_offset = (vmf->address - area->vm_start) >> PAGE_SHIFT;
-
- trace_i915_gem_object_fault(obj, page_offset, true, write);
-
- ret = i915_gem_object_pin_pages(obj);
- if (ret)
- goto err;
-
- wakeref = intel_runtime_pm_get(i915);
-
- srcu = i915_reset_trylock(i915);
- if (srcu < 0) {
- ret = srcu;
- goto err_rpm;
- }
-
- ret = i915_mutex_lock_interruptible(dev);
- if (ret)
- goto err_reset;
-
- /* Access to snoopable pages through the GTT is incoherent. */
- if (obj->cache_level != I915_CACHE_NONE && !HAS_LLC(i915)) {
- ret = -EFAULT;
- goto err_unlock;
- }
+ if (__prepare_object_fault(vmf, true, &fault))
+ return fault.error_ret;
/* Now pin it into the GTT as needed */
vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0,
@@ -291,7 +388,7 @@ vm_fault_t i915_gem_fault(struct vm_fault *vmf)
}
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
- goto err_unlock;
+ goto err;
}
ret = i915_vma_pin_fence(vma);
@@ -322,49 +419,8 @@ vm_fault_t i915_gem_fault(struct vm_fault *vmf)
i915_vma_unpin_fence(vma);
err_unpin:
__i915_vma_unpin(vma);
-err_unlock:
- mutex_unlock(&dev->struct_mutex);
-err_reset:
- i915_reset_unlock(i915, srcu);
-err_rpm:
- intel_runtime_pm_put(i915, wakeref);
- i915_gem_object_unpin_pages(obj);
err:
- switch (ret) {
- case -EIO:
- /*
- * We eat errors when the gpu is terminally wedged to avoid
- * userspace unduly crashing (gl has no provisions for mmaps to
- * fail). But any other -EIO isn't ours (e.g. swap in failure)
- * and so needs to be reported.
- */
- if (!i915_terminally_wedged(i915))
- return VM_FAULT_SIGBUS;
- /* else: fall through */
- case -EAGAIN:
- /*
- * EAGAIN means the gpu is hung and we'll wait for the error
- * handler to reset everything when re-faulting in
- * i915_mutex_lock_interruptible.
- */
- case 0:
- case -ERESTARTSYS:
- case -EINTR:
- case -EBUSY:
- /*
- * EBUSY is ok: this just means that another thread
- * already did the job.
- */
- return VM_FAULT_NOPAGE;
- case -ENOMEM:
- return VM_FAULT_OOM;
- case -ENOSPC:
- case -EFAULT:
- return VM_FAULT_SIGBUS;
- default:
- WARN_ONCE(ret, "unhandled error in %s: %i\n", __func__, ret);
- return VM_FAULT_SIGBUS;
- }
+ return __object_fault_fini(ret, &fault);
}
void __i915_gem_object_release_mmap(struct drm_i915_gem_object *obj)
--
2.19.1
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