[PATCH v6 2/5] dma-buf/sync_file: refactor fence storage in struct sync_file
Gustavo Padovan
gustavo at padovan.org
Fri Aug 5 13:39:35 UTC 2016
From: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
Create sync_file->fence to abstract the type of fence we are using for
each sync_file. If only one fence is present we use a normal struct fence
but if there is more fences to be added to the sync_file a fence_array
is created.
This change cleans up sync_file a bit. We don't need to have sync_file_cb
array anymore. Instead, as we always have one fence, only one fence
callback is registered per sync_file.
v2: Comments from Chris Wilson and Christian König
- Not using fence_ops anymore
- fence_is_array() was created to differentiate fence from fence_array
- fence_array_teardown() is now exported and used under fence_is_array()
- struct sync_file lost num_fences member
v3: Comments from Chris Wilson and Christian König
- struct sync_file lost status member in favor of fence_is_signaled()
- drop use of fence_array_teardown()
- use sizeof(*fence) to allocate only an array on fence pointers
v4: Comments from Chris Wilson
- use sizeof(*fence) to reallocate array
- fix typo in comments
- protect num_fences sum against overflows
- use array->base instead of casting the to struct fence
v5: fixes checkpatch warnings
v6: fix case where all fences are signaled.
Signed-off-by: Gustavo Padovan <gustavo.padovan at collabora.co.uk>
Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk>
Acked-by: Christian König <christian.koenig at amd.com>
Acked-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
drivers/dma-buf/sync_file.c | 174 +++++++++++++++++++++++------------
drivers/staging/android/sync_debug.c | 12 ++-
include/linux/sync_file.h | 17 +---
3 files changed, 129 insertions(+), 74 deletions(-)
diff --git a/drivers/dma-buf/sync_file.c b/drivers/dma-buf/sync_file.c
index 9aaa608..ac9c250 100644
--- a/drivers/dma-buf/sync_file.c
+++ b/drivers/dma-buf/sync_file.c
@@ -28,11 +28,11 @@
static const struct file_operations sync_file_fops;
-static struct sync_file *sync_file_alloc(int size)
+static struct sync_file *sync_file_alloc(void)
{
struct sync_file *sync_file;
- sync_file = kzalloc(size, GFP_KERNEL);
+ sync_file = kzalloc(sizeof(*sync_file), GFP_KERNEL);
if (!sync_file)
return NULL;
@@ -45,6 +45,8 @@ static struct sync_file *sync_file_alloc(int size)
init_waitqueue_head(&sync_file->wq);
+ INIT_LIST_HEAD(&sync_file->cb.node);
+
return sync_file;
err:
@@ -54,14 +56,11 @@ err:
static void fence_check_cb_func(struct fence *f, struct fence_cb *cb)
{
- struct sync_file_cb *check;
struct sync_file *sync_file;
- check = container_of(cb, struct sync_file_cb, cb);
- sync_file = check->sync_file;
+ sync_file = container_of(cb, struct sync_file, cb);
- if (atomic_dec_and_test(&sync_file->status))
- wake_up_all(&sync_file->wq);
+ wake_up_all(&sync_file->wq);
}
/**
@@ -76,22 +75,18 @@ struct sync_file *sync_file_create(struct fence *fence)
{
struct sync_file *sync_file;
- sync_file = sync_file_alloc(offsetof(struct sync_file, cbs[1]));
+ sync_file = sync_file_alloc();
if (!sync_file)
return NULL;
- sync_file->num_fences = 1;
- atomic_set(&sync_file->status, 1);
+ sync_file->fence = fence;
+
snprintf(sync_file->name, sizeof(sync_file->name), "%s-%s%llu-%d",
fence->ops->get_driver_name(fence),
fence->ops->get_timeline_name(fence), fence->context,
fence->seqno);
- sync_file->cbs[0].fence = fence;
- sync_file->cbs[0].sync_file = sync_file;
- if (fence_add_callback(fence, &sync_file->cbs[0].cb,
- fence_check_cb_func))
- atomic_dec(&sync_file->status);
+ fence_add_callback(fence, &sync_file->cb, fence_check_cb_func);
return sync_file;
}
@@ -121,14 +116,49 @@ err:
return NULL;
}
-static void sync_file_add_pt(struct sync_file *sync_file, int *i,
- struct fence *fence)
+static int sync_file_set_fence(struct sync_file *sync_file,
+ struct fence **fences, int num_fences)
{
- sync_file->cbs[*i].fence = fence;
- sync_file->cbs[*i].sync_file = sync_file;
+ struct fence_array *array;
+
+ /*
+ * The reference for the fences in the new sync_file and held
+ * in add_fence() during the merge procedure, so for num_fences == 1
+ * we already own a new reference to the fence. For num_fence > 1
+ * we own the reference of the fence_array creation.
+ */
+ if (num_fences == 1) {
+ sync_file->fence = fences[0];
+ } else {
+ array = fence_array_create(num_fences, fences,
+ fence_context_alloc(1), 1, false);
+ if (!array)
+ return -ENOMEM;
+
+ sync_file->fence = &array->base;
+ }
- if (!fence_add_callback(fence, &sync_file->cbs[*i].cb,
- fence_check_cb_func)) {
+ return 0;
+}
+
+static struct fence **get_fences(struct sync_file *sync_file, int *num_fences)
+{
+ if (fence_is_array(sync_file->fence)) {
+ struct fence_array *array = to_fence_array(sync_file->fence);
+
+ *num_fences = array->num_fences;
+ return array->fences;
+ }
+
+ *num_fences = 1;
+ return &sync_file->fence;
+}
+
+static void add_fence(struct fence **fences, int *i, struct fence *fence)
+{
+ fences[*i] = fence;
+
+ if (!fence_is_signaled(fence)) {
fence_get(fence);
(*i)++;
}
@@ -147,16 +177,24 @@ static void sync_file_add_pt(struct sync_file *sync_file, int *i,
static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
struct sync_file *b)
{
- int num_fences = a->num_fences + b->num_fences;
struct sync_file *sync_file;
- int i, i_a, i_b;
- unsigned long size = offsetof(struct sync_file, cbs[num_fences]);
+ struct fence **fences, **nfences, **a_fences, **b_fences;
+ int i, i_a, i_b, num_fences, a_num_fences, b_num_fences;
- sync_file = sync_file_alloc(size);
+ sync_file = sync_file_alloc();
if (!sync_file)
return NULL;
- atomic_set(&sync_file->status, num_fences);
+ a_fences = get_fences(a, &a_num_fences);
+ b_fences = get_fences(b, &b_num_fences);
+ if (a_num_fences > INT_MAX - b_num_fences)
+ return NULL;
+
+ num_fences = a_num_fences + b_num_fences;
+
+ fences = kcalloc(num_fences, sizeof(*fences), GFP_KERNEL);
+ if (!fences)
+ goto err;
/*
* Assume sync_file a and b are both ordered and have no
@@ -165,55 +203,73 @@ static struct sync_file *sync_file_merge(const char *name, struct sync_file *a,
* If a sync_file can only be created with sync_file_merge
* and sync_file_create, this is a reasonable assumption.
*/
- for (i = i_a = i_b = 0; i_a < a->num_fences && i_b < b->num_fences; ) {
- struct fence *pt_a = a->cbs[i_a].fence;
- struct fence *pt_b = b->cbs[i_b].fence;
+ for (i = i_a = i_b = 0; i_a < a_num_fences && i_b < b_num_fences; ) {
+ struct fence *pt_a = a_fences[i_a];
+ struct fence *pt_b = b_fences[i_b];
if (pt_a->context < pt_b->context) {
- sync_file_add_pt(sync_file, &i, pt_a);
+ add_fence(fences, &i, pt_a);
i_a++;
} else if (pt_a->context > pt_b->context) {
- sync_file_add_pt(sync_file, &i, pt_b);
+ add_fence(fences, &i, pt_b);
i_b++;
} else {
if (pt_a->seqno - pt_b->seqno <= INT_MAX)
- sync_file_add_pt(sync_file, &i, pt_a);
+ add_fence(fences, &i, pt_a);
else
- sync_file_add_pt(sync_file, &i, pt_b);
+ add_fence(fences, &i, pt_b);
i_a++;
i_b++;
}
}
- for (; i_a < a->num_fences; i_a++)
- sync_file_add_pt(sync_file, &i, a->cbs[i_a].fence);
+ for (; i_a < a_num_fences; i_a++)
+ add_fence(fences, &i, a_fences[i_a]);
+
+ for (; i_b < b_num_fences; i_b++)
+ add_fence(fences, &i, b_fences[i_b]);
+
+ if (i == 0) {
+ add_fence(fences, &i, a_fences[0]);
+ i++;
+ }
- for (; i_b < b->num_fences; i_b++)
- sync_file_add_pt(sync_file, &i, b->cbs[i_b].fence);
+ if (num_fences > i) {
+ nfences = krealloc(fences, i * sizeof(*fences),
+ GFP_KERNEL);
+ if (!nfences)
+ goto err;
+
+ fences = nfences;
+ }
+
+ if (sync_file_set_fence(sync_file, fences, i) < 0) {
+ kfree(fences);
+ goto err;
+ }
- if (num_fences > i)
- atomic_sub(num_fences - i, &sync_file->status);
- sync_file->num_fences = i;
+ fence_add_callback(sync_file->fence, &sync_file->cb,
+ fence_check_cb_func);
strlcpy(sync_file->name, name, sizeof(sync_file->name));
return sync_file;
+
+err:
+ fput(sync_file->file);
+ return NULL;
+
}
static void sync_file_free(struct kref *kref)
{
struct sync_file *sync_file = container_of(kref, struct sync_file,
kref);
- int i;
-
- for (i = 0; i < sync_file->num_fences; ++i) {
- fence_remove_callback(sync_file->cbs[i].fence,
- &sync_file->cbs[i].cb);
- fence_put(sync_file->cbs[i].fence);
- }
+ fence_remove_callback(sync_file->fence, &sync_file->cb);
+ fence_put(sync_file->fence);
kfree(sync_file);
}
@@ -232,9 +288,9 @@ static unsigned int sync_file_poll(struct file *file, poll_table *wait)
poll_wait(file, &sync_file->wq, wait);
- status = atomic_read(&sync_file->status);
+ status = fence_is_signaled(sync_file->fence);
- if (!status)
+ if (status)
return POLLIN;
if (status < 0)
return POLLERR;
@@ -315,8 +371,9 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
{
struct sync_file_info info;
struct sync_fence_info *fence_info = NULL;
+ struct fence **fences;
__u32 size;
- int ret, i;
+ int num_fences, ret, i;
if (copy_from_user(&info, (void __user *)arg, sizeof(info)))
return -EFAULT;
@@ -324,6 +381,8 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
if (info.flags || info.pad)
return -EINVAL;
+ fences = get_fences(sync_file, &num_fences);
+
/*
* Passing num_fences = 0 means that userspace doesn't want to
* retrieve any sync_fence_info. If num_fences = 0 we skip filling
@@ -333,16 +392,16 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
if (!info.num_fences)
goto no_fences;
- if (info.num_fences < sync_file->num_fences)
+ if (info.num_fences < num_fences)
return -EINVAL;
- size = sync_file->num_fences * sizeof(*fence_info);
+ size = num_fences * sizeof(*fence_info);
fence_info = kzalloc(size, GFP_KERNEL);
if (!fence_info)
return -ENOMEM;
- for (i = 0; i < sync_file->num_fences; ++i)
- sync_fill_fence_info(sync_file->cbs[i].fence, &fence_info[i]);
+ for (i = 0; i < num_fences; i++)
+ sync_fill_fence_info(fences[i], &fence_info[i]);
if (copy_to_user(u64_to_user_ptr(info.sync_fence_info), fence_info,
size)) {
@@ -352,11 +411,8 @@ static long sync_file_ioctl_fence_info(struct sync_file *sync_file,
no_fences:
strlcpy(info.name, sync_file->name, sizeof(info.name));
- info.status = atomic_read(&sync_file->status);
- if (info.status >= 0)
- info.status = !info.status;
-
- info.num_fences = sync_file->num_fences;
+ info.status = fence_is_signaled(sync_file->fence);
+ info.num_fences = num_fences;
if (copy_to_user((void __user *)arg, &info, sizeof(info)))
ret = -EFAULT;
diff --git a/drivers/staging/android/sync_debug.c b/drivers/staging/android/sync_debug.c
index 5f57499..e07958c 100644
--- a/drivers/staging/android/sync_debug.c
+++ b/drivers/staging/android/sync_debug.c
@@ -159,10 +159,16 @@ static void sync_print_sync_file(struct seq_file *s,
int i;
seq_printf(s, "[%p] %s: %s\n", sync_file, sync_file->name,
- sync_status_str(atomic_read(&sync_file->status)));
+ sync_status_str(!fence_is_signaled(sync_file->fence)));
- for (i = 0; i < sync_file->num_fences; ++i)
- sync_print_fence(s, sync_file->cbs[i].fence, true);
+ if (fence_is_array(sync_file->fence)) {
+ struct fence_array *array = to_fence_array(sync_file->fence);
+
+ for (i = 0; i < array->num_fences; ++i)
+ sync_print_fence(s, array->fences[i], true);
+ } else {
+ sync_print_fence(s, sync_file->fence, true);
+ }
}
static int sync_debugfs_show(struct seq_file *s, void *unused)
diff --git a/include/linux/sync_file.h b/include/linux/sync_file.h
index c6ffe8b..2efc5ec 100644
--- a/include/linux/sync_file.h
+++ b/include/linux/sync_file.h
@@ -19,12 +19,7 @@
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/fence.h>
-
-struct sync_file_cb {
- struct fence_cb cb;
- struct fence *fence;
- struct sync_file *sync_file;
-};
+#include <linux/fence-array.h>
/**
* struct sync_file - sync file to export to the userspace
@@ -32,10 +27,9 @@ struct sync_file_cb {
* @kref: reference count on fence.
* @name: name of sync_file. Useful for debugging
* @sync_file_list: membership in global file list
- * @num_fences: number of sync_pts in the fence
* @wq: wait queue for fence signaling
- * @status: 0: signaled, >0:active, <0: error
- * @cbs: sync_pts callback information
+ * @fence: fence with the fences in the sync_file
+ * @cb: fence callback information
*/
struct sync_file {
struct file *file;
@@ -44,12 +38,11 @@ struct sync_file {
#ifdef CONFIG_DEBUG_FS
struct list_head sync_file_list;
#endif
- int num_fences;
wait_queue_head_t wq;
- atomic_t status;
- struct sync_file_cb cbs[];
+ struct fence *fence;
+ struct fence_cb cb;
};
struct sync_file *sync_file_create(struct fence *fence);
--
2.5.5
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