[Intel-gfx] [RFC PATCH 082/162] HAX drm/i915/lmem: support pread and pwrite

Matthew Auld matthew.auld at intel.com
Fri Nov 27 12:05:58 UTC 2020


** DO NOT MERGE. PREAD/WRITE SUPPORT WILL BE DROPPED FROM DG1+ **

We need to add support for pread'ing and pwriting an LMEM object.

Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Signed-off-by: Steve Hampson <steven.t.hampson at intel.com>
Signed-off-by: Thomas Hellström <thomas.hellstrom at intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_lmem.c | 186 +++++++++++++++++++++++
 drivers/gpu/drm/i915/gem/i915_gem_lmem.h |   2 +
 2 files changed, 188 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_lmem.c b/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
index f6c4d5998ff9..840b68eb10d3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_lmem.c
@@ -8,6 +8,177 @@
 #include "gem/i915_gem_lmem.h"
 #include "i915_drv.h"
 
+static int
+i915_ww_pin_lock_interruptible(struct drm_i915_gem_object *obj)
+{
+	struct i915_gem_ww_ctx ww;
+	int ret;
+
+	for_i915_gem_ww(&ww, ret, true) {
+		ret = i915_gem_object_lock(obj, &ww);
+		if (ret)
+			continue;
+
+		ret = i915_gem_object_pin_pages(obj);
+		if (ret)
+			continue;
+
+		ret = i915_gem_object_set_to_wc_domain(obj, false);
+		if (ret)
+			goto out_unpin;
+
+		ret = i915_gem_object_wait(obj,
+					   I915_WAIT_INTERRUPTIBLE,
+					   MAX_SCHEDULE_TIMEOUT);
+		if (!ret)
+			continue;
+
+out_unpin:
+		i915_gem_object_unpin_pages(obj);
+
+		/* Unlocking is done implicitly */
+	}
+
+	return ret;
+}
+
+int i915_gem_object_lmem_pread(struct drm_i915_gem_object *obj,
+			       const struct drm_i915_gem_pread *arg)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct intel_runtime_pm *rpm = &i915->runtime_pm;
+	intel_wakeref_t wakeref;
+	char __user *user_data;
+	unsigned int offset;
+	unsigned long idx;
+	u64 remain;
+	int ret;
+
+	ret = i915_gem_object_wait(obj,
+				   I915_WAIT_INTERRUPTIBLE,
+				   MAX_SCHEDULE_TIMEOUT);
+	if (ret)
+		return ret;
+
+	ret = i915_ww_pin_lock_interruptible(obj);
+	if (ret)
+		return ret;
+
+	wakeref = intel_runtime_pm_get(rpm);
+
+	remain = arg->size;
+	user_data = u64_to_user_ptr(arg->data_ptr);
+	offset = offset_in_page(arg->offset);
+	for (idx = arg->offset >> PAGE_SHIFT; remain; idx++) {
+		unsigned long unwritten;
+		void __iomem *vaddr;
+		int length;
+
+		length = remain;
+		if (offset + length > PAGE_SIZE)
+			length = PAGE_SIZE - offset;
+
+		vaddr = i915_gem_object_lmem_io_map_page_atomic(obj, idx);
+		if (!vaddr) {
+			ret = -ENOMEM;
+			goto out_put;
+		}
+		unwritten = __copy_to_user_inatomic(user_data,
+						    (void __force *)vaddr + offset,
+						    length);
+		io_mapping_unmap_atomic(vaddr);
+		if (unwritten) {
+			vaddr = i915_gem_object_lmem_io_map_page(obj, idx);
+			unwritten = copy_to_user(user_data,
+						 (void __force *)vaddr + offset,
+						 length);
+			io_mapping_unmap(vaddr);
+		}
+		if (unwritten) {
+			ret = -EFAULT;
+			goto out_put;
+		}
+
+		remain -= length;
+		user_data += length;
+		offset = 0;
+	}
+
+out_put:
+	intel_runtime_pm_put(rpm, wakeref);
+	i915_gem_object_unpin_pages(obj);
+
+	return ret;
+}
+
+static int i915_gem_object_lmem_pwrite(struct drm_i915_gem_object *obj,
+				       const struct drm_i915_gem_pwrite *arg)
+{
+	struct drm_i915_private *i915 = to_i915(obj->base.dev);
+	struct intel_runtime_pm *rpm = &i915->runtime_pm;
+	intel_wakeref_t wakeref;
+	char __user *user_data;
+	unsigned int offset;
+	unsigned long idx;
+	u64 remain;
+	int ret;
+
+	ret = i915_gem_object_wait(obj,
+				   I915_WAIT_INTERRUPTIBLE,
+				   MAX_SCHEDULE_TIMEOUT);
+	if (ret)
+		return ret;
+
+	ret = i915_ww_pin_lock_interruptible(obj);
+	if (ret)
+		return ret;
+
+	wakeref = intel_runtime_pm_get(rpm);
+
+	remain = arg->size;
+	user_data = u64_to_user_ptr(arg->data_ptr);
+	offset = offset_in_page(arg->offset);
+	for (idx = arg->offset >> PAGE_SHIFT; remain; idx++) {
+		unsigned long unwritten;
+		void __iomem *vaddr;
+		int length;
+
+		length = remain;
+		if (offset + length > PAGE_SIZE)
+			length = PAGE_SIZE - offset;
+
+		vaddr = i915_gem_object_lmem_io_map_page_atomic(obj, idx);
+		if (!vaddr) {
+			ret = -ENOMEM;
+			goto out_put;
+		}
+
+		unwritten = __copy_from_user_inatomic_nocache((void __force *)vaddr + offset,
+							      user_data, length);
+		io_mapping_unmap_atomic(vaddr);
+		if (unwritten) {
+			vaddr = i915_gem_object_lmem_io_map_page(obj, idx);
+			unwritten = copy_from_user((void __force *)vaddr + offset,
+						   user_data, length);
+			io_mapping_unmap(vaddr);
+		}
+		if (unwritten) {
+			ret = -EFAULT;
+			goto out_put;
+		}
+
+		remain -= length;
+		user_data += length;
+		offset = 0;
+	}
+
+out_put:
+	intel_runtime_pm_put(rpm, wakeref);
+	i915_gem_object_unpin_pages(obj);
+
+	return ret;
+}
+
 const struct drm_i915_gem_object_ops i915_gem_lmem_obj_ops = {
 	.name = "i915_gem_object_lmem",
 	.flags = I915_GEM_OBJECT_HAS_IOMEM,
@@ -15,8 +186,23 @@ const struct drm_i915_gem_object_ops i915_gem_lmem_obj_ops = {
 	.get_pages = i915_gem_object_get_pages_buddy,
 	.put_pages = i915_gem_object_put_pages_buddy,
 	.release = i915_gem_object_release_memory_region,
+
+	.pread = i915_gem_object_lmem_pread,
+	.pwrite = i915_gem_object_lmem_pwrite,
 };
 
+void __iomem *
+i915_gem_object_lmem_io_map_page(struct drm_i915_gem_object *obj,
+				 unsigned long n)
+{
+	resource_size_t offset;
+
+	offset = i915_gem_object_get_dma_address(obj, n);
+	offset -= obj->mm.region->region.start;
+
+	return io_mapping_map_wc(&obj->mm.region->iomap, offset, PAGE_SIZE);
+}
+
 void __iomem *
 i915_gem_object_lmem_io_map_page_atomic(struct drm_i915_gem_object *obj,
 					unsigned long n)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_lmem.h b/drivers/gpu/drm/i915/gem/i915_gem_lmem.h
index bf7e11fad17b..a24d94bc380f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_lmem.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_lmem.h
@@ -14,6 +14,8 @@ struct intel_memory_region;
 
 extern const struct drm_i915_gem_object_ops i915_gem_lmem_obj_ops;
 
+void __iomem *i915_gem_object_lmem_io_map_page(struct drm_i915_gem_object *obj,
+					       unsigned long n);
 void __iomem *
 i915_gem_object_lmem_io_map_page_atomic(struct drm_i915_gem_object *obj,
 					unsigned long n);
-- 
2.26.2



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