cenalloc: some improvements.

Remove struct cenalloc_device * from exported functions prototype,
instead use global cenalloc_dev.

Add k{un}map_atomic dma_buf_ops functions.

Do fixes to avoid segfault when allocator has not been set.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>

3 files changed, 41 insertions, 36 deletions

diff --git a/drivers/cenalloc/cenalloc.c b/drivers/cenalloc/cenalloc.c
index e52d081334c0..786084a2621a 100644
--- a/drivers/cenalloc/cenalloc.c
+++ b/drivers/cenalloc/cenalloc.c
@@ -38,6 +38,8 @@
 #include "cenalloc.h"
 #include "cenalloc_priv.h"
 
+extern struct cenalloc_allocator system_contig;
+
 /*
  * Constraints-aware allocator framework helper is meant to facilitate
  * deferred allocation of backing storage for dma-buf buffers.
@@ -65,9 +67,9 @@ struct cenalloc_device {
 	struct rw_semaphore lock;
 
 	struct plist_head allocators;
-
 };
 
+static struct cenalloc_device cenalloc_dev;
 
 /* this function should only be called while dev->buffer_lock is held */
 static void cenalloc_buffer_add(struct cenalloc_device *dev,
@@ -106,8 +108,7 @@ static bool is_cenalloc_buffer(struct dma_buf *dmabuf);
  *	on success, pointer to the associated dma_buf;
  *	error if dma-buf cannot be exported or if it is out of memory.
  */
-struct dma_buf *cenalloc_buffer_create(struct cenalloc_device *dev,
-				     unsigned long len,
+struct dma_buf *cenalloc_buffer_create(unsigned long len,
 				     unsigned long align,
 				     unsigned long flags)
 {
@@ -121,7 +122,7 @@ struct dma_buf *cenalloc_buffer_create(struct cenalloc_device *dev,
 	buffer->flags = flags;
 	kref_init(&buffer->ref);
 
-	buffer->dev = dev;
+	buffer->dev = &cenalloc_dev;
 	buffer->size = len;
 	buffer->align = align;
 
@@ -135,9 +136,9 @@ struct dma_buf *cenalloc_buffer_create(struct cenalloc_device *dev,
 
 	mutex_init(&buffer->lock);
 
-	mutex_lock(&dev->buffer_lock);
-	cenalloc_buffer_add(dev, buffer);
-	mutex_unlock(&dev->buffer_lock);
+	mutex_lock(&cenalloc_dev.buffer_lock);
+	cenalloc_buffer_add(&cenalloc_dev, buffer);
+	mutex_unlock(&cenalloc_dev.buffer_lock);
 
 	return dmabuf;
 
@@ -150,10 +151,15 @@ EXPORT_SYMBOL_GPL(cenalloc_buffer_create);
 
 static void cenalloc_buffer_destroy(struct cenalloc_buffer *buffer)
 {
+	if (!buffer->allocator)
+		goto no_allocator;
+
 	if (WARN_ON(buffer->kmap_cnt > 0))
 		buffer->allocator->ops->unmap_kernel(buffer->allocator, buffer);
 	buffer->allocator->ops->unmap_dma(buffer->allocator, buffer);
 	buffer->allocator->ops->free(buffer);
+
+no_allocator:
 	kfree(buffer);
 }
 
@@ -296,7 +302,7 @@ static int cenalloc_find_allocator(struct cenalloc_device *dev,
 static struct sg_table *cenalloc_buffer_first_alloc(
 					struct cenalloc_buffer *buffer)
 {
-	struct cenalloc_allocator *allocator = buffer->allocator;
+	struct cenalloc_allocator *allocator;
 	struct sg_table *table;
 
 	int num_pages = PAGE_ALIGN(buffer->size) / PAGE_SIZE;
@@ -311,6 +317,8 @@ static struct sg_table *cenalloc_buffer_first_alloc(
 		return ERR_PTR(-ENODEV);
 	}
 
+	allocator = buffer->allocator;
+
 	ret = allocator->ops->allocate(allocator, buffer, buffer->size,
 						buffer->align, buffer->flags);
 	if (ret)
@@ -383,24 +391,20 @@ static struct sg_table *cenalloc_map_dma_buf(struct dma_buf_attachment *attach,
 {
 	struct dma_buf *dmabuf = attach->dmabuf;
 	struct cenalloc_buffer *buffer = dmabuf->priv;
-	struct sg_table *table = NULL;
 
 	if (!buffer->sg_table) {
 		down_read(&(buffer->dev->lock));
-		table = cenalloc_buffer_first_alloc(buffer);
+		buffer->sg_table = cenalloc_buffer_first_alloc(buffer);
 		up_read(&(buffer->dev->lock));
-		if (IS_ERR(table))
-			return table;
+		if (IS_ERR(buffer->sg_table))
+			return buffer->sg_table;
 	}
 
 	mutex_lock(&buffer->lock);
-	buffer->sg_table = table;
-
 	cenalloc_buffer_sync_for_device(buffer, attach->dev, direction);
 	mutex_unlock(&buffer->lock);
 
 	return buffer->sg_table;
-
 }
 
 static void cenalloc_unmap_dma_buf(struct dma_buf_attachment *attachment,
@@ -410,7 +414,8 @@ static void cenalloc_unmap_dma_buf(struct dma_buf_attachment *attachment,
 	struct dma_buf *dmabuf = attachment->dmabuf;
 	struct cenalloc_buffer *buffer = dmabuf->priv;
 
-	buffer->allocator->ops->unmap_dma(buffer->allocator, buffer);
+	if (buffer->allocator)
+		buffer->allocator->ops->unmap_dma(buffer->allocator, buffer);
 }
 
 static int cenalloc_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
@@ -514,6 +519,8 @@ static struct dma_buf_ops ca_dma_buf_ops = {
 	.end_cpu_access = cenalloc_dma_buf_end_cpu_access,
 	.kmap = cenalloc_dma_buf_kmap,
 	.kunmap = cenalloc_dma_buf_kunmap,
+	.kmap_atomic = cenalloc_dma_buf_kmap,
+	.kunmap_atomic = cenalloc_dma_buf_kunmap,
 };
 
 static bool is_cenalloc_buffer(struct dma_buf *dmabuf)
@@ -521,15 +528,14 @@ static bool is_cenalloc_buffer(struct dma_buf *dmabuf)
 	return(dmabuf->ops == &ca_dma_buf_ops);
 }
 
-static int cenalloc_buffer_getfd(struct cenalloc_device *dev,
-	     unsigned long len,
+static int cenalloc_buffer_getfd(unsigned long len,
 	     unsigned long align,
 	     unsigned long flags)
 {
 	struct dma_buf *dmabuf;
 	int fd;
 
-	dmabuf = cenalloc_buffer_create(dev, len, align, flags);
+	dmabuf = cenalloc_buffer_create(len, align, flags);
 	if (IS_ERR(dmabuf))
 		return PTR_ERR(dmabuf);
 
@@ -543,9 +549,6 @@ static int cenalloc_buffer_getfd(struct cenalloc_device *dev,
 
 static long cenalloc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
-
-	struct cenalloc_device *dev = filp->private_data;
-
 	int ret = 0;
 	int fd = 0;
 
@@ -560,8 +563,7 @@ static long cenalloc_ioctl(struct file *filp, unsigned int cmd, unsigned long ar
 	switch (cmd) {
 	case CA_IOC_CREATE:
 	{
-		fd = cenalloc_buffer_getfd(dev, data.len,
-						data.align, data.flags);
+		fd = cenalloc_buffer_getfd(data.len, data.align, data.flags);
 		if (fd < 0)
 			return -ENOMEM;
 
@@ -613,8 +615,7 @@ static const struct file_operations cenalloc_fops = {
  *	Adds an allocator to the cenalloc_device; This should be called at
  *	platform initialization time, for all allocators for the platform.
  */
-void cenalloc_device_add_allocator(struct cenalloc_device *dev,
-					struct cenalloc_allocator *allocator)
+void cenalloc_device_add_allocator(struct cenalloc_allocator *allocator)
 {
 
 	if (!allocator->ops->allocate || !allocator->ops->free ||
@@ -622,14 +623,14 @@ void cenalloc_device_add_allocator(struct cenalloc_device *dev,
 		pr_err("%s: can not add allocator with invalid ops struct.\n",
 		       __func__);
 
-	allocator->dev = dev;
-	down_write(&dev->lock);
+	allocator->dev = &cenalloc_dev;
+	down_write(&cenalloc_dev.lock);
 	/* use negative allocator->id to reverse the priority -- when traversing
 	   the list later attempt higher id numbers first */
 	plist_node_init(&allocator->node, -allocator->id);
-	plist_add(&allocator->node, &dev->allocators);
+	plist_add(&allocator->node, &cenalloc_dev.allocators);
 
-	up_write(&dev->lock);
+	up_write(&cenalloc_dev.lock);
 }
 EXPORT_SYMBOL_GPL(cenalloc_device_add_allocator);
 
@@ -643,6 +644,7 @@ static struct cenalloc_device cenalloc_dev = {
 		.dev.parent = NULL,
 };
 
+#if 0
 /*
  * TODO: this mechanism of getting a cenalloc device isn't the best,
  * Need to have a better way of getting handle to device.
@@ -652,6 +654,7 @@ struct cenalloc_device *cenalloc_get_device(void)
 	return &cenalloc_dev;
 }
 EXPORT_SYMBOL_GPL(cenalloc_get_device);
+#endif
 
 static int __init cenalloc_device_init(void)
 {
@@ -667,6 +670,9 @@ static int __init cenalloc_device_init(void)
 	mutex_init(&cenalloc_dev.buffer_lock);
 	init_rwsem(&cenalloc_dev.lock);
 	plist_head_init(&cenalloc_dev.allocators);
+
+	cenalloc_device_add_allocator(&system_contig);
+
 	return ret;
 }
 
diff --git a/drivers/cenalloc/cenalloc.h b/drivers/cenalloc/cenalloc.h
index c1d3a0e5ade8..6e2a13d5fe68 100644
--- a/drivers/cenalloc/cenalloc.h
+++ b/drivers/cenalloc/cenalloc.h
@@ -29,6 +29,7 @@
 
 #include "uapi/cenalloc.h"
 
+#if 0
 struct cenalloc_device;
 
 /**
@@ -39,6 +40,7 @@ struct cenalloc_device;
  * TODO: might need to have a better way of getting this device.
  */
 const struct cenalloc_device *cenalloc_get_device(void);
+#endif
 
 /**
  * cenalloc_buffer_create:
@@ -55,8 +57,7 @@ const struct cenalloc_device *cenalloc_get_device(void);
  * @flags:		flags for the buffer, if any
  *
  */
-struct dma_buf *cenalloc_buffer_create(struct cenalloc_device *dev,
-				     unsigned long len,
+struct dma_buf *cenalloc_buffer_create(unsigned long len,
 				     unsigned long align,
 				     unsigned long flags);
 
diff --git a/drivers/cenalloc/cenalloc_priv.h b/drivers/cenalloc/cenalloc_priv.h
index 31f5e5941e0c..f5115132ab4f 100644
--- a/drivers/cenalloc/cenalloc_priv.h
+++ b/drivers/cenalloc/cenalloc_priv.h
@@ -54,8 +54,8 @@
 #define CENALLOC_ALLOCATOR_SYSTEM_CONTIG_MASK	\
 					(1 << CENALLOC_ALLOCATOR_SYSTEM_CONTIG)
 
-
 struct cenalloc_device;
+
 /**
  * struct cenalloc_buffer - metadata for a particular buffer
  * @node:		node in the cenalloc_device buffers tree
@@ -172,11 +172,9 @@ struct cenalloc_allocator {
 
 /**
  * cenalloc_device_add_allocator - adds an allocator to the cenalloc device
- * @dev:	the device
  * @allocator:	the allocator to add
  */
-void cenalloc_device_add_allocator(struct cenalloc_device *dev,
-				struct cenalloc_allocator *allocator);
+void cenalloc_device_add_allocator(struct cenalloc_allocator *allocator);
 
 /**
  * TODO: add some helpers for common allocator operations on buffers;