Fault handler to handle missing pages for shmem-backed objects. Handle also
logic needed to refault pages depending on fault handler usage.
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@xxxxxxxxxxxxxxx>
Signed-off-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_domain.c | 2 +-
drivers/gpu/drm/i915/gem/i915_gem_mman.c | 189 ++++++++++++++++-----
drivers/gpu/drm/i915/gem/i915_gem_object.h | 2 +-
drivers/gpu/drm/i915/i915_gem.c | 2 +-
4 files changed, 149 insertions(+), 46 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_domain.c b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
index 9c58e8fac1d9..517e73c3aa31 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_domain.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_domain.c
@@ -254,7 +254,7 @@ int i915_gem_object_set_cache_level(struct drm_i915_gem_object *obj,
}
if (obj->userfault_count)
- __i915_gem_object_release_mmap(obj);
+ __i915_gem_object_release_mmap_gtt(obj);
/*
* As we no longer need a fence for GTT access,
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index 87690aa64814..d0a653a9a4cc 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -5,6 +5,7 @@
*/
#include <linux/mman.h>
+#include <linux/pfn_t.h>
#include <linux/sizes.h>
#include "gt/intel_gt.h"
@@ -199,6 +200,45 @@ compute_partial_view(const struct drm_i915_gem_object *obj,
return view;
}
+static vm_fault_t i915_error_to_vmf_fault(int err, struct intel_gt *gt)
+{
+ switch (err) {
+ 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 (!intel_gt_is_wedged(gt))
+ 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(err, "unhandled error in %s: %i\n", __func__, err);
+ return VM_FAULT_SIGBUS;
+ }
+}
+
/**
* i915_gem_fault - fault a page into the GTT
* @vmf: fault info
@@ -336,44 +376,48 @@ vm_fault_t i915_gem_fault(struct vm_fault *vmf)
intel_runtime_pm_put(rpm, 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 (!intel_gt_is_wedged(ggtt->vm.gt))
- 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 i915_error_to_vmf_fault(ret, ggtt->vm.gt);
+}
+
+static vm_fault_t i915_gem_fault_cpu(struct vm_fault *vmf)
+{
+ struct vm_area_struct *area = vmf->vma;
+ struct i915_mmap_offset *priv = area->vm_private_data;
+ struct drm_i915_gem_object *obj = priv->obj;
+ struct drm_device *dev = obj->base.dev;
+ struct drm_i915_private *dev_priv = to_i915(dev);
+ vm_fault_t vmf_ret;
+ unsigned long size = area->vm_end - area->vm_start;
+ bool write = area->vm_flags & VM_WRITE;
+ int i, ret;
+
+ /* Sanity check that we allow writing into this object */
+ if (i915_gem_object_is_readonly(obj) && write)
return VM_FAULT_SIGBUS;
+
+ ret = i915_gem_object_pin_pages(obj);
+ if (ret)
+ return i915_error_to_vmf_fault(ret, &dev_priv->gt);
+
+ for (i = 0; i < size >> PAGE_SHIFT; i++) {
+ struct page *page = i915_gem_object_get_page(obj, i);
+
+ vmf_ret = vmf_insert_pfn(area,
+ (unsigned long)area->vm_start + i * PAGE_SIZE,
+ page_to_pfn(page));
+ if (vmf_ret & VM_FAULT_ERROR) {
+ vmf_ret = i915_error_to_vmf_fault(vm_fault_to_errno(vmf_ret, 0),
+ &dev_priv->gt);
+ break;
+ }
}
+
+ i915_gem_object_unpin_pages(obj);
+
+ return vmf_ret;
}
-void __i915_gem_object_release_mmap(struct drm_i915_gem_object *obj)
+void __i915_gem_object_release_mmap_gtt(struct drm_i915_gem_object *obj)
{
struct i915_vma *vma;
struct i915_mmap_offset *mmo;
@@ -396,12 +440,6 @@ void __i915_gem_object_release_mmap(struct drm_i915_gem_object *obj)
}
/**
- * i915_gem_object_release_mmap - remove physical page mappings
- * @obj: obj in question
- *
- * Preserve the reservation of the mmapping with the DRM core code, but
- * relinquish ownership of the pages back to the system.
- *
* It is vital that we remove the page mapping if we have mapped a tiled
* object through the GTT and then lose the fence register due to
* resource pressure. Similarly if the object has been moved out of the
@@ -409,7 +447,7 @@ void __i915_gem_object_release_mmap(struct drm_i915_gem_object *obj)
* mapping will then trigger a page fault on the next user access, allowing
* fixup by i915_gem_fault().
*/
-void i915_gem_object_release_mmap(struct drm_i915_gem_object *obj)
+static void i915_gem_object_release_mmap_gtt(struct drm_i915_gem_object *obj)
{
struct drm_i915_private *i915 = to_i915(obj->base.dev);
intel_wakeref_t wakeref;
@@ -428,7 +466,7 @@ void i915_gem_object_release_mmap(struct drm_i915_gem_object *obj)
if (!obj->userfault_count)
goto out;
- __i915_gem_object_release_mmap(obj);
+ __i915_gem_object_release_mmap_gtt(obj);
/* Ensure that the CPU's PTE are revoked and there are not outstanding
* memory transactions from userspace before we return. The TLB
@@ -444,6 +482,35 @@ void i915_gem_object_release_mmap(struct drm_i915_gem_object *obj)
intel_runtime_pm_put(&i915->runtime_pm, wakeref);
}
+static void i915_gem_object_release_mmap_offset(struct drm_i915_gem_object *obj)
+{
+ struct i915_mmap_offset *mmo;
+
+ mutex_lock(&obj->mmo_lock);
+ list_for_each_entry(mmo, &obj->mmap_offsets, offset) {
+ /* vma_node_unmap for GTT mmaps handled already in
+ * __i915_gem_object_release_mmap_gtt
+ */
+ if (mmo->mmap_type != I915_MMAP_TYPE_GTT)
+ drm_vma_node_unmap(&mmo->vma_node,
+ obj->base.dev->anon_inode->i_mapping);
+ }
+ mutex_unlock(&obj->mmo_lock);
+}
+
+/**
+ * i915_gem_object_release_mmap - remove physical page mappings
+ * @obj: obj in question
+ *
+ * Preserve the reservation of the mmapping with the DRM core code, but
+ * relinquish ownership of the pages back to the system.
+ */
+void i915_gem_object_release_mmap(struct drm_i915_gem_object *obj)
+{
+ i915_gem_object_release_mmap_gtt(obj);
+ i915_gem_object_release_mmap_offset(obj);
+}
+
static void init_mmap_offset(struct drm_i915_gem_object *obj,
struct i915_mmap_offset *mmo)
{
@@ -627,6 +694,33 @@ static const struct vm_operations_struct i915_gem_gtt_vm_ops = {
.close = i915_gem_vm_close,
};
+static const struct vm_operations_struct i915_gem_cpu_vm_ops = {
+ .fault = i915_gem_fault_cpu,
+ .open = i915_gem_vm_open,
+ .close = i915_gem_vm_close,
+};
+
+static void set_vmdata_mmap_offset(struct i915_mmap_offset *mmo, struct vm_area_struct *vma)
+{
+ switch (mmo->mmap_type) {
+ case I915_MMAP_TYPE_OFFSET_WC:
+ vma->vm_page_prot =
+ pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
+ break;
+ case I915_MMAP_TYPE_OFFSET_WB:
+ vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+ break;
+ case I915_MMAP_TYPE_OFFSET_UC:
+ vma->vm_page_prot =
+ pgprot_noncached(vm_get_page_prot(vma->vm_flags));
+ break;
+ default:
+ break;
+ }
+
+ vma->vm_ops = &i915_gem_cpu_vm_ops;
+}
+
/* This overcomes the limitation in drm_gem_mmap's assignment of a
* drm_gem_object as the vma->vm_private_data. Since we need to
* be able to resolve multiple mmap offsets which could be tied
@@ -683,7 +777,16 @@ int i915_gem_mmap(struct file *filp, struct vm_area_struct *vma)
vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
vma->vm_private_data = mmo;
- vma->vm_ops = &i915_gem_gtt_vm_ops;
+ switch (mmo->mmap_type) {
+ case I915_MMAP_TYPE_OFFSET_WC:
+ case I915_MMAP_TYPE_OFFSET_WB:
+ case I915_MMAP_TYPE_OFFSET_UC:
+ set_vmdata_mmap_offset(mmo, vma);
+ break;
+ case I915_MMAP_TYPE_GTT:
+ vma->vm_ops = &i915_gem_gtt_vm_ops;
+ break;
+ }
/*
* Take a ref for our mmap_offset object. The reference is cleaned
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index d667ed8bb0a6..012e5d1d99cc 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -338,7 +338,7 @@ static inline void i915_gem_object_unpin_map(struct drm_i915_gem_object *obj)
i915_gem_object_unpin_pages(obj);
}
-void __i915_gem_object_release_mmap(struct drm_i915_gem_object *obj);
+void __i915_gem_object_release_mmap_gtt(struct drm_i915_gem_object *obj);
void i915_gem_object_release_mmap(struct drm_i915_gem_object *obj);
void
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 95e7c52cf8ed..363b35ba559d 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -857,7 +857,7 @@ void i915_gem_runtime_suspend(struct drm_i915_private *i915)
list_for_each_entry_safe(obj, on,
&i915->ggtt.userfault_list, userfault_link)
- __i915_gem_object_release_mmap(obj);
+ __i915_gem_object_release_mmap_gtt(obj);
/*
* The fence will be lost when the device powers down. If any were
--
2.23.0
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