android-5.4/ANDROID-staging-ion-refactor-ion-s-buffer-manipulators-into-a-separate-file.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Sandeep Patil <sspatil@google.com>
Date: Wed, 7 Aug 2019 12:12:47 -0700
Subject: ANDROID: staging: ion: refactor ion's buffer manipulators into a
 separate file.

This patch is preparatory work for making ion heaps modular. The patch
itself doesn't make any significant changes except for re-organizing the
buffer manipulator functions in a single file. This will be helpful
later when we specifically export some of these functions to be used by
a heap module.

Bug: 133508579
Test: ion-unit-tests

Change-Id: I7438bd529a3e9c7a90910979e26bd754a8292e9a
Co-developed-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Sandeep Patil <sspatil@google.com>
---
 drivers/staging/android/ion/Makefile      |   2 +-
 drivers/staging/android/ion/ion.c         | 143 +---------------
 drivers/staging/android/ion/ion.h         |  15 --
 drivers/staging/android/ion/ion_buffer.c  | 198 ++++++++++++++++++++++
 drivers/staging/android/ion/ion_heap.c    |   6 +-
 drivers/staging/android/ion/ion_private.h |  47 +++++
 6 files changed, 254 insertions(+), 157 deletions(-)
 create mode 100644 drivers/staging/android/ion/ion_buffer.c
 create mode 100644 drivers/staging/android/ion/ion_private.h

diff --git a/drivers/staging/android/ion/Makefile b/drivers/staging/android/ion/Makefile
index 5f4487b1a224..da386dbf3ffd 100644
--- a/drivers/staging/android/ion/Makefile
+++ b/drivers/staging/android/ion/Makefile
@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_ION) += ion.o ion_heap.o
+obj-$(CONFIG_ION) += ion.o ion_buffer.o ion_heap.o
 obj-$(CONFIG_ION_SYSTEM_HEAP) += ion_system_heap.o ion_page_pool.o
 obj-$(CONFIG_ION_CMA_HEAP) += ion_cma_heap.o
diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index 2e5c6ae2f3fc..19d3e82b2f5b 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -26,119 +26,11 @@
 #include <linux/uaccess.h>
 #include <linux/vmalloc.h>
 
-#include "ion.h"
+#include "ion_private.h"
 
 static struct ion_device *internal_dev;
 static int heap_id;
 
-/* this function should only be called while dev->lock is held */
-static struct ion_buffer *ion_buffer_create(struct ion_heap *heap,
-					    struct ion_device *dev,
-					    unsigned long len,
-					    unsigned long flags)
-{
-	struct ion_buffer *buffer;
-	int ret;
-
-	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
-	if (!buffer)
-		return ERR_PTR(-ENOMEM);
-
-	buffer->heap = heap;
-	buffer->flags = flags;
-	buffer->dev = dev;
-	buffer->size = len;
-
-	ret = heap->ops->allocate(heap, buffer, len, flags);
-
-	if (ret) {
-		if (!(heap->flags & ION_HEAP_FLAG_DEFER_FREE))
-			goto err2;
-
-		ion_heap_freelist_drain(heap, 0);
-		ret = heap->ops->allocate(heap, buffer, len, flags);
-		if (ret)
-			goto err2;
-	}
-
-	if (!buffer->sg_table) {
-		WARN_ONCE(1, "This heap needs to set the sgtable");
-		ret = -EINVAL;
-		goto err1;
-	}
-
-	spin_lock(&heap->stat_lock);
-	heap->num_of_buffers++;
-	heap->num_of_alloc_bytes += len;
-	if (heap->num_of_alloc_bytes > heap->alloc_bytes_wm)
-		heap->alloc_bytes_wm = heap->num_of_alloc_bytes;
-	spin_unlock(&heap->stat_lock);
-
-	INIT_LIST_HEAD(&buffer->attachments);
-	mutex_init(&buffer->lock);
-	return buffer;
-
-err1:
-	heap->ops->free(buffer);
-err2:
-	kfree(buffer);
-	return ERR_PTR(ret);
-}
-
-void ion_buffer_destroy(struct ion_buffer *buffer)
-{
-	if (buffer->kmap_cnt > 0) {
-		pr_warn_once("%s: buffer still mapped in the kernel\n",
-			     __func__);
-		buffer->heap->ops->unmap_kernel(buffer->heap, buffer);
-	}
-	buffer->heap->ops->free(buffer);
-	spin_lock(&buffer->heap->stat_lock);
-	buffer->heap->num_of_buffers--;
-	buffer->heap->num_of_alloc_bytes -= buffer->size;
-	spin_unlock(&buffer->heap->stat_lock);
-
-	kfree(buffer);
-}
-
-static void _ion_buffer_destroy(struct ion_buffer *buffer)
-{
-	struct ion_heap *heap = buffer->heap;
-
-	if (heap->flags & ION_HEAP_FLAG_DEFER_FREE)
-		ion_heap_freelist_add(heap, buffer);
-	else
-		ion_buffer_destroy(buffer);
-}
-
-static void *ion_buffer_kmap_get(struct ion_buffer *buffer)
-{
-	void *vaddr;
-
-	if (buffer->kmap_cnt) {
-		buffer->kmap_cnt++;
-		return buffer->vaddr;
-	}
-	vaddr = buffer->heap->ops->map_kernel(buffer->heap, buffer);
-	if (WARN_ONCE(!vaddr,
-		      "heap->ops->map_kernel should return ERR_PTR on error"))
-		return ERR_PTR(-EINVAL);
-	if (IS_ERR(vaddr))
-		return vaddr;
-	buffer->vaddr = vaddr;
-	buffer->kmap_cnt++;
-	return vaddr;
-}
-
-static void ion_buffer_kmap_put(struct ion_buffer *buffer)
-{
-	buffer->kmap_cnt--;
-	if (!buffer->kmap_cnt) {
-		buffer->heap->ops->unmap_kernel(buffer->heap, buffer);
-		buffer->vaddr = NULL;
-	}
-}
-
 static struct sg_table *dup_sg_table(struct sg_table *table)
 {
 	struct sg_table *new_table;
@@ -273,7 +165,7 @@ static void ion_dma_buf_release(struct dma_buf *dmabuf)
 {
 	struct ion_buffer *buffer = dmabuf->priv;
 
-	_ion_buffer_destroy(buffer);
+	ion_buffer_destroy(internal_dev, buffer);
 }
 
 static void *ion_dma_buf_kmap(struct dma_buf *dmabuf, unsigned long offset)
@@ -358,39 +250,14 @@ static const struct dma_buf_ops dma_buf_ops = {
 static struct dma_buf *ion_alloc_dmabuf(size_t len, unsigned int heap_id_mask,
 					unsigned int flags)
 {
-	struct ion_device *dev = internal_dev;
-	struct ion_buffer *buffer = NULL;
-	struct ion_heap *heap;
+	struct ion_buffer *buffer;
 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 	struct dma_buf *dmabuf;
 
 	pr_debug("%s: len %zu heap_id_mask %u flags %x\n", __func__,
 		 len, heap_id_mask, flags);
-	/*
-	 * traverse the list of heaps available in this system in priority
-	 * order.  If the heap type is supported by the client, and matches the
-	 * request of the caller allocate from it.  Repeat until allocate has
-	 * succeeded or all heaps have been tried
-	 */
-	len = PAGE_ALIGN(len);
-
-	if (!len)
-		return ERR_PTR(-EINVAL);
-
-	down_read(&dev->lock);
-	plist_for_each_entry(heap, &dev->heaps, node) {
-		/* if the caller didn't specify this heap id */
-		if (!((1 << heap->id) & heap_id_mask))
-			continue;
-		buffer = ion_buffer_create(heap, dev, len, flags);
-		if (!IS_ERR(buffer))
-			break;
-	}
-	up_read(&dev->lock);
-
-	if (!buffer)
-		return ERR_PTR(-ENODEV);
 
+	buffer = ion_buffer_alloc(internal_dev, len, heap_id_mask, flags);
 	if (IS_ERR(buffer))
 		return ERR_CAST(buffer);
 
@@ -401,7 +268,7 @@ static struct dma_buf *ion_alloc_dmabuf(size_t len, unsigned int heap_id_mask,
 
 	dmabuf = dma_buf_export(&exp_info);
 	if (IS_ERR(dmabuf))
-		_ion_buffer_destroy(buffer);
+		ion_buffer_destroy(internal_dev, buffer);
 
 	return dmabuf;
 }
diff --git a/drivers/staging/android/ion/ion.h b/drivers/staging/android/ion/ion.h
index 6f9f7c365f38..d2d18f03ac77 100644
--- a/drivers/staging/android/ion/ion.h
+++ b/drivers/staging/android/ion/ion.h
@@ -17,7 +17,6 @@
 #include <linux/sched.h>
 #include <linux/shrinker.h>
 #include <linux/types.h>
-#include <linux/miscdevice.h>
 
 #include "../uapi/ion.h"
 
@@ -39,7 +38,6 @@
  */
 struct ion_buffer {
 	struct list_head list;
-	struct ion_device *dev;
 	struct ion_heap *heap;
 	unsigned long flags;
 	unsigned long private_flags;
@@ -54,19 +52,6 @@ struct ion_buffer {
 
 void ion_buffer_destroy(struct ion_buffer *buffer);
 
-/**
- * struct ion_device - the metadata of the ion device node
- * @dev:		the actual misc device
- * @lock:		rwsem protecting the tree of heaps and clients
- */
-struct ion_device {
-	struct miscdevice dev;
-	struct rw_semaphore lock;
-	struct plist_head heaps;
-	struct dentry *debug_root;
-	int heap_cnt;
-};
-
 /**
  * struct ion_heap_ops - ops to operate on a given heap
  * @allocate:		allocate memory
diff --git a/drivers/staging/android/ion/ion_buffer.c b/drivers/staging/android/ion/ion_buffer.c
new file mode 100644
index 000000000000..8b8dd1e216d4
--- /dev/null
+++ b/drivers/staging/android/ion/ion_buffer.c
@@ -0,0 +1,198 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ION Memory Allocator - buffer interface
+ *
+ * Copyright (c) 2019, Google, Inc.
+ */
+
+#include <linux/mm.h>
+#include <linux/slab.h>
+
+#include "ion_private.h"
+
+/* this function should only be called while dev->lock is held */
+static void ion_buffer_add(struct ion_device *dev,
+			   struct ion_buffer *buffer)
+{
+	struct rb_node **p = &dev->buffers.rb_node;
+	struct rb_node *parent = NULL;
+	struct ion_buffer *entry;
+
+	while (*p) {
+		parent = *p;
+		entry = rb_entry(parent, struct ion_buffer, node);
+
+		if (buffer < entry) {
+			p = &(*p)->rb_left;
+		} else if (buffer > entry) {
+			p = &(*p)->rb_right;
+		} else {
+			pr_err("%s: buffer already found.", __func__);
+			BUG();
+		}
+	}
+
+	rb_link_node(&buffer->node, parent, p);
+	rb_insert_color(&buffer->node, &dev->buffers);
+}
+
+/* this function should only be called while dev->lock is held */
+static struct ion_buffer *ion_buffer_create(struct ion_heap *heap,
+					    struct ion_device *dev,
+					    unsigned long len,
+					    unsigned long flags)
+{
+	struct ion_buffer *buffer;
+	int ret;
+
+	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
+	if (!buffer)
+		return ERR_PTR(-ENOMEM);
+
+	buffer->heap = heap;
+	buffer->flags = flags;
+	buffer->size = len;
+
+	ret = heap->ops->allocate(heap, buffer, len, flags);
+
+	if (ret) {
+		if (!(heap->flags & ION_HEAP_FLAG_DEFER_FREE))
+			goto err2;
+
+		ion_heap_freelist_drain(heap, 0);
+		ret = heap->ops->allocate(heap, buffer, len, flags);
+		if (ret)
+			goto err2;
+	}
+
+	if (!buffer->sg_table) {
+		WARN_ONCE(1, "This heap needs to set the sgtable");
+		ret = -EINVAL;
+		goto err1;
+	}
+
+	spin_lock(&heap->stat_lock);
+	heap->num_of_buffers++;
+	heap->num_of_alloc_bytes += len;
+	if (heap->num_of_alloc_bytes > heap->alloc_bytes_wm)
+		heap->alloc_bytes_wm = heap->num_of_alloc_bytes;
+	spin_unlock(&heap->stat_lock);
+
+	INIT_LIST_HEAD(&buffer->attachments);
+	mutex_init(&buffer->lock);
+	mutex_lock(&dev->buffer_lock);
+	ion_buffer_add(dev, buffer);
+	mutex_unlock(&dev->buffer_lock);
+	return buffer;
+
+err1:
+	heap->ops->free(buffer);
+err2:
+	kfree(buffer);
+	return ERR_PTR(ret);
+}
+
+struct ion_buffer *ion_buffer_alloc(struct ion_device *dev, size_t len,
+				    unsigned int heap_id_mask,
+				    unsigned int flags)
+{
+	struct ion_buffer *buffer = NULL;
+	struct ion_heap *heap;
+
+	if (!dev || !len) {
+		return ERR_PTR(-EINVAL);
+	}
+
+	/*
+	 * traverse the list of heaps available in this system in priority
+	 * order.  If the heap type is supported by the client, and matches the
+	 * request of the caller allocate from it.  Repeat until allocate has
+	 * succeeded or all heaps have been tried
+	 */
+	len = PAGE_ALIGN(len);
+	if (!len)
+		return ERR_PTR(-EINVAL);
+
+	down_read(&dev->lock);
+	plist_for_each_entry(heap, &dev->heaps, node) {
+		/* if the caller didn't specify this heap id */
+		if (!((1 << heap->id) & heap_id_mask))
+			continue;
+		buffer = ion_buffer_create(heap, dev, len, flags);
+		if (!IS_ERR(buffer))
+			break;
+	}
+	up_read(&dev->lock);
+
+	if (!buffer)
+		return ERR_PTR(-ENODEV);
+
+	if (IS_ERR(buffer))
+		return ERR_CAST(buffer);
+
+	return buffer;
+}
+
+void ion_buffer_release(struct ion_buffer *buffer)
+{
+	if (buffer->kmap_cnt > 0) {
+		pr_warn_once("%s: buffer still mapped in the kernel\n",
+			     __func__);
+		buffer->heap->ops->unmap_kernel(buffer->heap, buffer);
+	}
+	buffer->heap->ops->free(buffer);
+	spin_lock(&buffer->heap->stat_lock);
+	buffer->heap->num_of_buffers--;
+	buffer->heap->num_of_alloc_bytes -= buffer->size;
+	spin_unlock(&buffer->heap->stat_lock);
+
+	kfree(buffer);
+}
+
+void ion_buffer_destroy(struct ion_device *dev, struct ion_buffer *buffer)
+{
+	struct ion_heap *heap;
+
+	if (!dev || !buffer) {
+		pr_warn("%s: invalid argument\n", __func__);
+		return;
+	}
+
+	heap = buffer->heap;
+	mutex_lock(&dev->buffer_lock);
+	rb_erase(&buffer->node, &dev->buffers);
+	mutex_unlock(&dev->buffer_lock);
+
+	if (heap->flags & ION_HEAP_FLAG_DEFER_FREE)
+		ion_heap_freelist_add(heap, buffer);
+	else
+		ion_buffer_release(buffer);
+}
+
+void *ion_buffer_kmap_get(struct ion_buffer *buffer)
+{
+	void *vaddr;
+
+	if (buffer->kmap_cnt) {
+		buffer->kmap_cnt++;
+		return buffer->vaddr;
+	}
+	vaddr = buffer->heap->ops->map_kernel(buffer->heap, buffer);
+	if (WARN_ONCE(!vaddr,
+		      "heap->ops->map_kernel should return ERR_PTR on error"))
+		return ERR_PTR(-EINVAL);
+	if (IS_ERR(vaddr))
+		return vaddr;
+	buffer->vaddr = vaddr;
+	buffer->kmap_cnt++;
+	return vaddr;
+}
+
+void ion_buffer_kmap_put(struct ion_buffer *buffer)
+{
+	buffer->kmap_cnt--;
+	if (!buffer->kmap_cnt) {
+		buffer->heap->ops->unmap_kernel(buffer->heap, buffer);
+		buffer->vaddr = NULL;
+	}
+}
diff --git a/drivers/staging/android/ion/ion_heap.c b/drivers/staging/android/ion/ion_heap.c
index 473b465724f1..3b4f32b9cd2d 100644
--- a/drivers/staging/android/ion/ion_heap.c
+++ b/drivers/staging/android/ion/ion_heap.c
@@ -15,7 +15,7 @@
 #include <linux/scatterlist.h>
 #include <linux/vmalloc.h>
 
-#include "ion.h"
+#include "ion_private.h"
 
 void *ion_heap_map_kernel(struct ion_heap *heap,
 			  struct ion_buffer *buffer)
@@ -198,7 +198,7 @@ static size_t _ion_heap_freelist_drain(struct ion_heap *heap, size_t size,
 			buffer->private_flags |= ION_PRIV_FLAG_SHRINKER_FREE;
 		total_drained += buffer->size;
 		spin_unlock(&heap->free_lock);
-		ion_buffer_destroy(buffer);
+		ion_buffer_release(buffer);
 		spin_lock(&heap->free_lock);
 	}
 	spin_unlock(&heap->free_lock);
@@ -236,7 +236,7 @@ static int ion_heap_deferred_free(void *data)
 		list_del(&buffer->list);
 		heap->free_list_size -= buffer->size;
 		spin_unlock(&heap->free_lock);
-		ion_buffer_destroy(buffer);
+		ion_buffer_release(buffer);
 	}
 
 	return 0;
diff --git a/drivers/staging/android/ion/ion_private.h b/drivers/staging/android/ion/ion_private.h
new file mode 100644
index 000000000000..e80692c885b4
--- /dev/null
+++ b/drivers/staging/android/ion/ion_private.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * ION Memory Allocator - Internal header
+ *
+ * Copyright (C) 2019 Google, Inc.
+ */
+
+#ifndef _ION_PRIVATE_H
+#define _ION_PRIVATE_H
+
+#include <linux/dcache.h>
+#include <linux/miscdevice.h>
+#include <linux/mutex.h>
+#include <linux/plist.h>
+#include <linux/rbtree.h>
+#include <linux/rwsem.h>
+#include <linux/types.h>
+
+#include "ion.h"
+
+/**
+ * struct ion_device - the metadata of the ion device node
+ * @dev:		the actual misc device
+ * @buffers:		an rb tree of all the existing buffers
+ * @buffer_lock:	lock protecting the tree of buffers
+ * @lock:		rwsem protecting the tree of heaps and clients
+ */
+struct ion_device {
+	struct miscdevice dev;
+	struct rb_root buffers;
+	struct mutex buffer_lock;
+	struct rw_semaphore lock;
+	struct plist_head heaps;
+	struct dentry *debug_root;
+	int heap_cnt;
+};
+
+/* ion_buffer manipulators */
+extern struct ion_buffer *ion_buffer_alloc(struct ion_device *dev, size_t len,
+					   unsigned int heap_id_mask,
+					   unsigned int flags);
+extern void ion_buffer_release(struct ion_buffer *buffer);
+extern void ion_buffer_destroy(struct ion_device *dev, struct ion_buffer *buffer);
+extern void *ion_buffer_kmap_get(struct ion_buffer *buffer);
+extern void ion_buffer_kmap_put(struct ion_buffer *buffer);
+
+#endif /* _ION_PRIVATE_H */