[RFC PATCH 29/42] drm/i915: Set correct vmf source pages for gem objects

Matthew Auld
2019-02-14T14:58:19Z

From: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>

This allows page-faults from objects with different backing stores
from a single interface.

Signed-off-by: Abdiel Janulgue <abdiel.janulgue@linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
---
drivers/gpu/drm/i915/i915_drv.c | 2 +-
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_gem.c | 58 +++++++++++++++++++++++-
drivers/gpu/drm/i915/i915_gem_object.h | 6 ++-
drivers/gpu/drm/i915/intel_region_lmem.c | 28 ++++++++++++
5 files changed, 92 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index dc446430a340..b1200d7ebd13 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -2944,7 +2944,7 @@ static const struct file_operations i915_driver_fops = {
.open = drm_open,
.release = drm_release,
.unlocked_ioctl = drm_ioctl,
- .mmap = drm_gem_mmap,
+ .mmap = i915_gem_mmap,
.poll = drm_poll,
.read = drm_read,
.compat_ioctl = i915_compat_ioctl,
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 772fffa87545..065953a9264f 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3071,6 +3071,7 @@ int i915_gem_wait_for_idle(struct drm_i915_private *dev_priv,
int __must_check i915_gem_suspend(struct drm_i915_private *dev_priv);
void i915_gem_suspend_late(struct drm_i915_private *dev_priv);
void i915_gem_resume(struct drm_i915_private *dev_priv);
+int i915_gem_mmap(struct file *filp, struct vm_area_struct *vma);
vm_fault_t i915_gem_fault(struct vm_fault *vmf);
int i915_gem_object_wait(struct drm_i915_gem_object *obj,
unsigned int flags,
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 95e31529a738..48dbb57fbc6d 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -38,6 +38,7 @@
#include <linux/pci.h>
#include <linux/dma-buf.h>
#include <linux/mman.h>
+#include <linux/pfn_t.h>

#include "i915_drv.h"
#include "i915_gem_clflush.h"
@@ -377,6 +378,7 @@ static const struct drm_i915_gem_object_ops i915_gem_phys_ops = {
.get_pages = i915_gem_object_get_pages_phys,
.put_pages = i915_gem_object_put_pages_phys,
.release = i915_gem_object_release_phys,
+ .vmf_fill_pages = i915_gem_vmf_fill_pages_cpu,
};

static const struct drm_i915_gem_object_ops i915_gem_object_ops;
@@ -1938,7 +1940,7 @@ vm_fault_t i915_gem_fault(struct vm_fault *vmf)
goto err_unlock;
}

- ret = __vmf_fill_pages_gtt(obj, vmf, page_offset);
+ ret = obj->ops->vmf_fill_pages(obj, vmf, page_offset);

err_unlock:
mutex_unlock(&dev->struct_mutex);
@@ -2166,6 +2168,26 @@ i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
return i915_gem_mmap_gtt(file, dev, args->handle, &args->offset);
}

+int i915_gem_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ int ret;
+ struct drm_i915_gem_object *obj;
+
+ ret = drm_gem_mmap(filp, vma);
+ if (ret < 0)
+ return ret;
+
+ obj = to_intel_bo(vma->vm_private_data);
+ if (obj->memory_region) {
+ if (obj->mmap_origin == I915_MMAP_ORIGIN_OFFSET) {
+ vma->vm_flags &= ~VM_PFNMAP;
+ vma->vm_flags |= VM_MIXEDMAP;
+ }
+ }
+
+ return ret;
+}
+
/* Immediately discard the backing storage */
static void
i915_gem_object_truncate(struct drm_i915_gem_object *obj)
@@ -4194,6 +4216,37 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj,
i915_gem_info_add_obj(to_i915(obj->base.dev), obj->base.size);
}

+int i915_gem_vmf_fill_pages_cpu(struct drm_i915_gem_object *obj,
+ struct vm_fault *vmf,
+ pgoff_t page_offset)
+{
+ struct vm_area_struct *area = vmf->vma;
+ struct drm_device *dev = obj->base.dev;
+ struct drm_i915_private *dev_priv = to_i915(dev);
+ struct page *page;
+ unsigned long pfn;
+ vm_fault_t vmf_ret;
+ pgoff_t pg_off = (vmf->address - area->vm_start) >> PAGE_SHIFT;
+
+ if (HAS_MAPPABLE_APERTURE(dev_priv))
+ return __vmf_fill_pages_gtt(obj, vmf, page_offset);
+
+ page = i915_gem_object_get_page(obj, pg_off);
+ pfn = page_to_pfn(page);
+
+ vmf_ret = vmf_insert_mixed(area, vmf->address,
+ __pfn_to_pfn_t(pfn, PFN_DEV));
+ if (vmf_ret & VM_FAULT_ERROR)
+ return vm_fault_to_errno(vmf_ret, 0);
+
+ if (!obj->userfault_count++)
+ list_add(&obj->userfault_link, &dev_priv->mm.userfault_list);
+
+ GEM_BUG_ON(!obj->userfault_count);
+
+ return 0;
+}
+
static const struct drm_i915_gem_object_ops i915_gem_object_ops = {
.flags = I915_GEM_OBJECT_HAS_STRUCT_PAGE |
I915_GEM_OBJECT_IS_SHRINKABLE,
@@ -4202,6 +4255,7 @@ static const struct drm_i915_gem_object_ops i915_gem_object_ops = {
.put_pages = i915_gem_object_put_pages_gtt,

.pwrite = i915_gem_object_pwrite_gtt,
+ .vmf_fill_pages = i915_gem_vmf_fill_pages_cpu,
};

static int i915_gem_object_create_shmem(struct drm_device *dev,
@@ -4818,6 +4872,8 @@ static void __i915_gem_free_objects(struct drm_i915_private *i915,
spin_unlock(&i915->mm.obj_lock);
}

+
+ i915_gem_release_mmap(obj);
mutex_unlock(&i915->drm.struct_mutex);

GEM_BUG_ON(obj->bind_count);
diff --git a/drivers/gpu/drm/i915/i915_gem_object.h b/drivers/gpu/drm/i915/i915_gem_object.h
index f5b8bca33fe3..5c6bbe6f5e84 100644
--- a/drivers/gpu/drm/i915/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/i915_gem_object.h
@@ -82,6 +82,8 @@ struct drm_i915_gem_object_ops {

int (*dmabuf_export)(struct drm_i915_gem_object *);
void (*release)(struct drm_i915_gem_object *);
+ int (*vmf_fill_pages)(struct drm_i915_gem_object *, struct vm_fault *,
+ pgoff_t);
};

struct drm_i915_gem_object {
@@ -520,5 +522,7 @@ void i915_gem_object_set_cache_coherency(struct drm_i915_gem_object *obj,
unsigned int cache_level);
void i915_gem_object_flush_if_display(struct drm_i915_gem_object *obj);

+int i915_gem_vmf_fill_pages_cpu(struct drm_i915_gem_object *obj,
+ struct vm_fault *vmf,
+ pgoff_t page_offset);
#endif
-
diff --git a/drivers/gpu/drm/i915/intel_region_lmem.c b/drivers/gpu/drm/i915/intel_region_lmem.c
index d549242a3578..b8b6b8248737 100644
--- a/drivers/gpu/drm/i915/intel_region_lmem.c
+++ b/drivers/gpu/drm/i915/intel_region_lmem.c
@@ -170,12 +170,40 @@ static int region_lmem_pwrite(struct drm_i915_gem_object *obj,
return ret;
}

+static int region_lmem_vmf_fill_pages(struct drm_i915_gem_object *obj,
+ struct vm_fault *vmf,
+ pgoff_t page_offset)
+{
+ struct vm_area_struct *area = vmf->vma;
+ struct drm_device *dev = obj->base.dev;
+ struct drm_i915_private *i915 = to_i915(dev);
+ unsigned long size = area->vm_end - area->vm_start;
+ int i;
+ vm_fault_t vmf_ret;
+
+ for (i = 0; i < size >> PAGE_SHIFT; i++) {
+ vmf_ret = vmf_insert_pfn(area,
+ (unsigned long)area->vm_start + i * PAGE_SIZE,
+ i915_gem_object_lmem_io_pfn(obj, i));
+ if (vmf_ret & VM_FAULT_ERROR)
+ return vm_fault_to_errno(vmf_ret, 0);
+ }
+
+ if (!obj->userfault_count++)
+ list_add(&obj->userfault_link, &i915->mm.userfault_list);
+
+ GEM_BUG_ON(!obj->userfault_count);
+
+ return 0;
+}
+
static const struct drm_i915_gem_object_ops region_lmem_obj_ops = {
.get_pages = i915_memory_region_get_pages_buddy,
.put_pages = i915_memory_region_put_pages_buddy,
.release = i915_gem_object_release_memory_region,
.pread = region_lmem_pread,
.pwrite = region_lmem_pwrite,
+ .vmf_fill_pages = region_lmem_vmf_fill_pages,
};

static struct drm_i915_gem_object *
--
2.20.1