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authorLinus Torvalds <torvalds@linux-foundation.org>2016-06-01 12:32:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-06-01 12:32:25 -0700
commitebb8cb2bae0344ef45cc173cdf5402ec91198abd (patch)
tree7c21eb9c7a7bf9714035bd243e776e01747206ae /drivers
parent6b15d6650c5301ce023d8df0cc3a60b1a76d377e (diff)
parentb02da6f8236148009c22167cd7013d5ce04a2d37 (diff)
Merge tag 'dma-buf-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/sumits/dma-buf
Pull dma-buf updates from Sumit Semwal: - use of vma_pages instead of explicit computation - DocBook and headerdoc updates for dma-buf * tag 'dma-buf-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/sumits/dma-buf: dma-buf: use vma_pages() fence: add missing descriptions for fence doc: update/fixup dma-buf related DocBook reservation: add headerdoc comments dma-buf: headerdoc fixes
Diffstat (limited to 'drivers')
-rw-r--r--drivers/dma-buf/dma-buf.c7
-rw-r--r--drivers/dma-buf/reservation.c72
2 files changed, 72 insertions, 7 deletions
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 4a2c07ee6677..6355ab38d630 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -33,6 +33,7 @@
#include <linux/seq_file.h>
#include <linux/poll.h>
#include <linux/reservation.h>
+#include <linux/mm.h>
#include <uapi/linux/dma-buf.h>
@@ -90,7 +91,7 @@ static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
dmabuf = file->private_data;
/* check for overflowing the buffer's size */
- if (vma->vm_pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) >
+ if (vma->vm_pgoff + vma_pages(vma) >
dmabuf->size >> PAGE_SHIFT)
return -EINVAL;
@@ -723,11 +724,11 @@ int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
return -EINVAL;
/* check for offset overflow */
- if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) < pgoff)
+ if (pgoff + vma_pages(vma) < pgoff)
return -EOVERFLOW;
/* check for overflowing the buffer's size */
- if (pgoff + ((vma->vm_end - vma->vm_start) >> PAGE_SHIFT) >
+ if (pgoff + vma_pages(vma) >
dmabuf->size >> PAGE_SHIFT)
return -EINVAL;
diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
index c0bd5722c997..9566a62ad8e3 100644
--- a/drivers/dma-buf/reservation.c
+++ b/drivers/dma-buf/reservation.c
@@ -35,6 +35,17 @@
#include <linux/reservation.h>
#include <linux/export.h>
+/**
+ * DOC: Reservation Object Overview
+ *
+ * The reservation object provides a mechanism to manage shared and
+ * exclusive fences associated with a buffer. A reservation object
+ * can have attached one exclusive fence (normally associated with
+ * write operations) or N shared fences (read operations). The RCU
+ * mechanism is used to protect read access to fences from locked
+ * write-side updates.
+ */
+
DEFINE_WW_CLASS(reservation_ww_class);
EXPORT_SYMBOL(reservation_ww_class);
@@ -43,9 +54,17 @@ EXPORT_SYMBOL(reservation_seqcount_class);
const char reservation_seqcount_string[] = "reservation_seqcount";
EXPORT_SYMBOL(reservation_seqcount_string);
-/*
- * Reserve space to add a shared fence to a reservation_object,
- * must be called with obj->lock held.
+
+/**
+ * reservation_object_reserve_shared - Reserve space to add a shared
+ * fence to a reservation_object.
+ * @obj: reservation object
+ *
+ * Should be called before reservation_object_add_shared_fence(). Must
+ * be called with obj->lock held.
+ *
+ * RETURNS
+ * Zero for success, or -errno
*/
int reservation_object_reserve_shared(struct reservation_object *obj)
{
@@ -180,7 +199,11 @@ done:
fence_put(old_fence);
}
-/*
+/**
+ * reservation_object_add_shared_fence - Add a fence to a shared slot
+ * @obj: the reservation object
+ * @fence: the shared fence to add
+ *
* Add a fence to a shared slot, obj->lock must be held, and
* reservation_object_reserve_shared_fence has been called.
*/
@@ -200,6 +223,13 @@ void reservation_object_add_shared_fence(struct reservation_object *obj,
}
EXPORT_SYMBOL(reservation_object_add_shared_fence);
+/**
+ * reservation_object_add_excl_fence - Add an exclusive fence.
+ * @obj: the reservation object
+ * @fence: the shared fence to add
+ *
+ * Add a fence to the exclusive slot. The obj->lock must be held.
+ */
void reservation_object_add_excl_fence(struct reservation_object *obj,
struct fence *fence)
{
@@ -233,6 +263,18 @@ void reservation_object_add_excl_fence(struct reservation_object *obj,
}
EXPORT_SYMBOL(reservation_object_add_excl_fence);
+/**
+ * reservation_object_get_fences_rcu - Get an object's shared and exclusive
+ * fences without update side lock held
+ * @obj: the reservation object
+ * @pfence_excl: the returned exclusive fence (or NULL)
+ * @pshared_count: the number of shared fences returned
+ * @pshared: the array of shared fence ptrs returned (array is krealloc'd to
+ * the required size, and must be freed by caller)
+ *
+ * RETURNS
+ * Zero or -errno
+ */
int reservation_object_get_fences_rcu(struct reservation_object *obj,
struct fence **pfence_excl,
unsigned *pshared_count,
@@ -319,6 +361,18 @@ unlock:
}
EXPORT_SYMBOL_GPL(reservation_object_get_fences_rcu);
+/**
+ * reservation_object_wait_timeout_rcu - Wait on reservation's objects
+ * shared and/or exclusive fences.
+ * @obj: the reservation object
+ * @wait_all: if true, wait on all fences, else wait on just exclusive fence
+ * @intr: if true, do interruptible wait
+ * @timeout: timeout value in jiffies or zero to return immediately
+ *
+ * RETURNS
+ * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or
+ * greater than zer on success.
+ */
long reservation_object_wait_timeout_rcu(struct reservation_object *obj,
bool wait_all, bool intr,
unsigned long timeout)
@@ -416,6 +470,16 @@ reservation_object_test_signaled_single(struct fence *passed_fence)
return ret;
}
+/**
+ * reservation_object_test_signaled_rcu - Test if a reservation object's
+ * fences have been signaled.
+ * @obj: the reservation object
+ * @test_all: if true, test all fences, otherwise only test the exclusive
+ * fence
+ *
+ * RETURNS
+ * true if all fences signaled, else false
+ */
bool reservation_object_test_signaled_rcu(struct reservation_object *obj,
bool test_all)
{