[PATCH v8 02/22] drm/i915/vm_bind: Add __i915_sw_fence_await_reservation()

[Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>]

Add function __i915_sw_fence_await_reservation() for
asynchronous wait on a dma-resv object with specified
dma_resv_usage. This is required for async vma unbind
with vm_bind.

Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
---
 drivers/gpu/drm/i915/i915_sw_fence.c | 28 +++++++++++++++++++++-------
 drivers/gpu/drm/i915/i915_sw_fence.h | 23 +++++++++++++++++------
 2 files changed, 38 insertions(+), 13 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c
index cc2a8821d22a..ae06d35db056 100644
--- a/drivers/gpu/drm/i915/i915_sw_fence.c
+++ b/drivers/gpu/drm/i915/i915_sw_fence.c
@@ -7,7 +7,6 @@
 #include <linux/slab.h>
 #include <linux/dma-fence.h>
 #include <linux/irq_work.h>
-#include <linux/dma-resv.h>
 
 #include "i915_sw_fence.h"
 #include "i915_selftest.h"
@@ -569,11 +568,26 @@ int __i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
 	return ret;
 }
 
-int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
-				    struct dma_resv *resv,
-				    bool write,
-				    unsigned long timeout,
-				    gfp_t gfp)
+/**
+ * __i915_sw_fence_await_reservation() - Setup a fence to wait on a dma-resv
+ * object with specified usage.
+ * @fence: the fence that needs to wait
+ * @resv: dma-resv object
+ * @usage: dma_resv_usage (See enum dma_resv_usage)
+ * @timeout: how long to wait in jiffies
+ * @gfp: allocation mode
+ *
+ * Setup the @fence to asynchronously wait on dma-resv object @resv for
+ * @usage to complete before signaling.
+ *
+ * Returns 0 if there is nothing to wait on, -ve error code upon error
+ * and >0 upon successfully setting up the wait.
+ */
+int __i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
+				      struct dma_resv *resv,
+				      enum dma_resv_usage usage,
+				      unsigned long timeout,
+				      gfp_t gfp)
 {
 	struct dma_resv_iter cursor;
 	struct dma_fence *f;
@@ -582,7 +596,7 @@ int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
 	debug_fence_assert(fence);
 	might_sleep_if(gfpflags_allow_blocking(gfp));
 
-	dma_resv_iter_begin(&cursor, resv, dma_resv_usage_rw(write));
+	dma_resv_iter_begin(&cursor, resv, usage);
 	dma_resv_for_each_fence_unlocked(&cursor, f) {
 		pending = i915_sw_fence_await_dma_fence(fence, f, timeout,
 							gfp);
diff --git a/drivers/gpu/drm/i915/i915_sw_fence.h b/drivers/gpu/drm/i915/i915_sw_fence.h
index f752bfc7c6e1..9c4859dc4c0d 100644
--- a/drivers/gpu/drm/i915/i915_sw_fence.h
+++ b/drivers/gpu/drm/i915/i915_sw_fence.h
@@ -10,13 +10,13 @@
 #define _I915_SW_FENCE_H_
 
 #include <linux/dma-fence.h>
+#include <linux/dma-resv.h>
 #include <linux/gfp.h>
 #include <linux/kref.h>
 #include <linux/notifier.h> /* for NOTIFY_DONE */
 #include <linux/wait.h>
 
 struct completion;
-struct dma_resv;
 struct i915_sw_fence;
 
 enum i915_sw_fence_notify {
@@ -89,11 +89,22 @@ int i915_sw_fence_await_dma_fence(struct i915_sw_fence *fence,
 				  unsigned long timeout,
 				  gfp_t gfp);
 
-int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
-				    struct dma_resv *resv,
-				    bool write,
-				    unsigned long timeout,
-				    gfp_t gfp);
+int __i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
+				      struct dma_resv *resv,
+				      enum dma_resv_usage usage,
+				      unsigned long timeout,
+				      gfp_t gfp);
+
+static inline int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
+						  struct dma_resv *resv,
+						  bool write,
+						  unsigned long timeout,
+						  gfp_t gfp)
+{
+	return __i915_sw_fence_await_reservation(fence, resv,
+						 dma_resv_usage_rw(write),
+						 timeout, gfp);
+}
 
 bool i915_sw_fence_await(struct i915_sw_fence *fence);
 void i915_sw_fence_complete(struct i915_sw_fence *fence);
-- 
2.21.0.rc0.32.g243a4c7e27