Re: [PATCH 02/16] drm/i915/vm_bind: Add __i915_sw_fence_await_reservation()

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

On Wed, Sep 28, 2022 at 06:39:05PM +0100, Matthew Auld wrote:
>On 28/09/2022 07:19, Niranjana Vishwanathapura wrote:
>>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.
>>
>>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..b7a10c374a08 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
>>+ * @usage to complete before signaling.
>
>s/usage @usage/@usage/ ?

Thanks for the review Matt.
Sure, will fix.

>
>>+ *
>>+ * Returns 0 if there is nothing to wait on, -ve upon error and >0 upon
>
>What does "-ve" mean btw?
>

-ve error code. Will update

Regards,
Niranjana

>Acked-by: Matthew Auld <matthew.auld@intel.com>
>
>>+ * 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);