android-5.4/ANDROID-staging-ion-refactor-ion-s-dmabuf-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 15:01:24 -0700
Subject: ANDROID: staging: ion: refactor ion's dmabuf 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: I52ecea78a179c936006a21beb7630009984cb22f
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         | 254 +---------------------
 drivers/staging/android/ion/ion_buffer.c  |   6 +-
 drivers/staging/android/ion/ion_dma_buf.c | 252 +++++++++++++++++++++
 drivers/staging/android/ion/ion_private.h |  11 +-
 include/linux/ion.h                       |  16 +-
 6 files changed, 289 insertions(+), 252 deletions(-)
 create mode 100644 drivers/staging/android/ion/ion_dma_buf.c

diff --git a/drivers/staging/android/ion/Makefile b/drivers/staging/android/ion/Makefile
index da386dbf3ffd..b6fab2816781 100644
--- a/drivers/staging/android/ion/Makefile
+++ b/drivers/staging/android/ion/Makefile
@@ -1,4 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
-obj-$(CONFIG_ION) += ion.o ion_buffer.o ion_heap.o
+obj-$(CONFIG_ION) += ion.o ion_buffer.o ion_dma_buf.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 19d3e82b2f5b..c80a31da371b 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -17,276 +17,38 @@
 #include <linux/fs.h>
 #include <linux/kthread.h>
 #include <linux/list.h>
-#include <linux/miscdevice.h>
 #include <linux/mm.h>
 #include <linux/mm_types.h>
 #include <linux/rbtree.h>
 #include <linux/sched/task.h>
 #include <linux/slab.h>
 #include <linux/uaccess.h>
-#include <linux/vmalloc.h>
 
 #include "ion_private.h"
 
 static struct ion_device *internal_dev;
 static int heap_id;
 
-static struct sg_table *dup_sg_table(struct sg_table *table)
-{
-	struct sg_table *new_table;
-	int ret, i;
-	struct scatterlist *sg, *new_sg;
-
-	new_table = kzalloc(sizeof(*new_table), GFP_KERNEL);
-	if (!new_table)
-		return ERR_PTR(-ENOMEM);
-
-	ret = sg_alloc_table(new_table, table->nents, GFP_KERNEL);
-	if (ret) {
-		kfree(new_table);
-		return ERR_PTR(-ENOMEM);
-	}
-
-	new_sg = new_table->sgl;
-	for_each_sg(table->sgl, sg, table->nents, i) {
-		memcpy(new_sg, sg, sizeof(*sg));
-		new_sg->dma_address = 0;
-		new_sg = sg_next(new_sg);
-	}
-
-	return new_table;
-}
-
-static void free_duped_table(struct sg_table *table)
-{
-	sg_free_table(table);
-	kfree(table);
-}
-
-struct ion_dma_buf_attachment {
-	struct device *dev;
-	struct sg_table *table;
-	struct list_head list;
-};
-
-static int ion_dma_buf_attach(struct dma_buf *dmabuf,
-			      struct dma_buf_attachment *attachment)
-{
-	struct ion_dma_buf_attachment *a;
-	struct sg_table *table;
-	struct ion_buffer *buffer = dmabuf->priv;
-
-	a = kzalloc(sizeof(*a), GFP_KERNEL);
-	if (!a)
-		return -ENOMEM;
-
-	table = dup_sg_table(buffer->sg_table);
-	if (IS_ERR(table)) {
-		kfree(a);
-		return -ENOMEM;
-	}
-
-	a->table = table;
-	a->dev = attachment->dev;
-	INIT_LIST_HEAD(&a->list);
-
-	attachment->priv = a;
-
-	mutex_lock(&buffer->lock);
-	list_add(&a->list, &buffer->attachments);
-	mutex_unlock(&buffer->lock);
-
-	return 0;
-}
-
-static void ion_dma_buf_detatch(struct dma_buf *dmabuf,
-				struct dma_buf_attachment *attachment)
-{
-	struct ion_dma_buf_attachment *a = attachment->priv;
-	struct ion_buffer *buffer = dmabuf->priv;
-
-	mutex_lock(&buffer->lock);
-	list_del(&a->list);
-	mutex_unlock(&buffer->lock);
-	free_duped_table(a->table);
-
-	kfree(a);
-}
-
-static struct sg_table *ion_map_dma_buf(struct dma_buf_attachment *attachment,
-					enum dma_data_direction direction)
-{
-	struct ion_dma_buf_attachment *a = attachment->priv;
-	struct sg_table *table;
-
-	table = a->table;
-
-	if (!dma_map_sg(attachment->dev, table->sgl, table->nents,
-			direction))
-		return ERR_PTR(-ENOMEM);
-
-	return table;
-}
-
-static void ion_unmap_dma_buf(struct dma_buf_attachment *attachment,
-			      struct sg_table *table,
-			      enum dma_data_direction direction)
-{
-	dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction);
-}
-
-static int ion_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
-{
-	struct ion_buffer *buffer = dmabuf->priv;
-	int ret = 0;
-
-	if (!buffer->heap->ops->map_user) {
-		pr_err("%s: this heap does not define a method for mapping to userspace\n",
-		       __func__);
-		return -EINVAL;
-	}
-
-	if (!(buffer->flags & ION_FLAG_CACHED))
-		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
-
-	mutex_lock(&buffer->lock);
-	/* now map it to userspace */
-	ret = buffer->heap->ops->map_user(buffer->heap, buffer, vma);
-	mutex_unlock(&buffer->lock);
-
-	if (ret)
-		pr_err("%s: failure mapping buffer to userspace\n",
-		       __func__);
-
-	return ret;
-}
-
-static void ion_dma_buf_release(struct dma_buf *dmabuf)
-{
-	struct ion_buffer *buffer = dmabuf->priv;
-
-	ion_buffer_destroy(internal_dev, buffer);
-}
-
-static void *ion_dma_buf_kmap(struct dma_buf *dmabuf, unsigned long offset)
-{
-	struct ion_buffer *buffer = dmabuf->priv;
-
-	return buffer->vaddr + offset * PAGE_SIZE;
-}
-
-static void ion_dma_buf_kunmap(struct dma_buf *dmabuf, unsigned long offset,
-			       void *ptr)
-{
-}
-
-static int ion_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
-					enum dma_data_direction direction)
-{
-	struct ion_buffer *buffer = dmabuf->priv;
-	void *vaddr;
-	struct ion_dma_buf_attachment *a;
-	int ret = 0;
-
-	/*
-	 * TODO: Move this elsewhere because we don't always need a vaddr
-	 */
-	if (buffer->heap->ops->map_kernel) {
-		mutex_lock(&buffer->lock);
-		vaddr = ion_buffer_kmap_get(buffer);
-		if (IS_ERR(vaddr)) {
-			ret = PTR_ERR(vaddr);
-			goto unlock;
-		}
-		mutex_unlock(&buffer->lock);
-	}
-
-	mutex_lock(&buffer->lock);
-	list_for_each_entry(a, &buffer->attachments, list) {
-		dma_sync_sg_for_cpu(a->dev, a->table->sgl, a->table->nents,
-				    direction);
-	}
-
-unlock:
-	mutex_unlock(&buffer->lock);
-	return ret;
-}
-
-static int ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
-				      enum dma_data_direction direction)
-{
-	struct ion_buffer *buffer = dmabuf->priv;
-	struct ion_dma_buf_attachment *a;
-
-	if (buffer->heap->ops->map_kernel) {
-		mutex_lock(&buffer->lock);
-		ion_buffer_kmap_put(buffer);
-		mutex_unlock(&buffer->lock);
-	}
-
-	mutex_lock(&buffer->lock);
-	list_for_each_entry(a, &buffer->attachments, list) {
-		dma_sync_sg_for_device(a->dev, a->table->sgl, a->table->nents,
-				       direction);
-	}
-	mutex_unlock(&buffer->lock);
-
-	return 0;
-}
-
-static const struct dma_buf_ops dma_buf_ops = {
-	.map_dma_buf = ion_map_dma_buf,
-	.unmap_dma_buf = ion_unmap_dma_buf,
-	.mmap = ion_mmap,
-	.release = ion_dma_buf_release,
-	.attach = ion_dma_buf_attach,
-	.detach = ion_dma_buf_detatch,
-	.begin_cpu_access = ion_dma_buf_begin_cpu_access,
-	.end_cpu_access = ion_dma_buf_end_cpu_access,
-	.map = ion_dma_buf_kmap,
-	.unmap = ion_dma_buf_kunmap,
-};
-
-static struct dma_buf *ion_alloc_dmabuf(size_t len, unsigned int heap_id_mask,
-					unsigned int flags)
-{
-	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);
-
-	buffer = ion_buffer_alloc(internal_dev, len, heap_id_mask, flags);
-	if (IS_ERR(buffer))
-		return ERR_CAST(buffer);
-
-	exp_info.ops = &dma_buf_ops;
-	exp_info.size = buffer->size;
-	exp_info.flags = O_RDWR;
-	exp_info.priv = buffer;
-
-	dmabuf = dma_buf_export(&exp_info);
-	if (IS_ERR(dmabuf))
-		ion_buffer_destroy(internal_dev, buffer);
-
-	return dmabuf;
-}
-
+/* Entry into ION allocator for rest of the kernel */
 struct dma_buf *ion_alloc(size_t len, unsigned int heap_id_mask,
 			  unsigned int flags)
 {
-	return ion_alloc_dmabuf(len, heap_id_mask, flags);
+	return ion_dmabuf_alloc(internal_dev, len, heap_id_mask, flags);
 }
 EXPORT_SYMBOL_GPL(ion_alloc);
 
+int ion_free(struct ion_buffer *buffer)
+{
+	return ion_buffer_destroy(internal_dev, buffer);
+}
+
 static int ion_alloc_fd(size_t len, unsigned int heap_id_mask,
 			unsigned int flags)
 {
 	int fd;
 	struct dma_buf *dmabuf;
 
-	dmabuf = ion_alloc_dmabuf(len, heap_id_mask, flags);
+	dmabuf = ion_dmabuf_alloc(internal_dev, len, heap_id_mask, flags);
 	if (IS_ERR(dmabuf))
 		return PTR_ERR(dmabuf);
 
diff --git a/drivers/staging/android/ion/ion_buffer.c b/drivers/staging/android/ion/ion_buffer.c
index 8b8dd1e216d4..c10ea6672f1a 100644
--- a/drivers/staging/android/ion/ion_buffer.c
+++ b/drivers/staging/android/ion/ion_buffer.c
@@ -149,13 +149,13 @@ void ion_buffer_release(struct ion_buffer *buffer)
 	kfree(buffer);
 }
 
-void ion_buffer_destroy(struct ion_device *dev, struct ion_buffer *buffer)
+int 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;
+		return -EINVAL;
 	}
 
 	heap = buffer->heap;
@@ -167,6 +167,8 @@ void ion_buffer_destroy(struct ion_device *dev, struct ion_buffer *buffer)
 		ion_heap_freelist_add(heap, buffer);
 	else
 		ion_buffer_release(buffer);
+
+	return 0;
 }
 
 void *ion_buffer_kmap_get(struct ion_buffer *buffer)
diff --git a/drivers/staging/android/ion/ion_dma_buf.c b/drivers/staging/android/ion/ion_dma_buf.c
new file mode 100644
index 000000000000..0de08e6f1af5
--- /dev/null
+++ b/drivers/staging/android/ion/ion_dma_buf.c
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ION Memory Allocator - dmabuf interface
+ *
+ * Copyright (c) 2019, Google, Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include "ion_private.h"
+
+static struct sg_table *dup_sg_table(struct sg_table *table)
+{
+	struct sg_table *new_table;
+	int ret, i;
+	struct scatterlist *sg, *new_sg;
+
+	new_table = kzalloc(sizeof(*new_table), GFP_KERNEL);
+	if (!new_table)
+		return ERR_PTR(-ENOMEM);
+
+	ret = sg_alloc_table(new_table, table->nents, GFP_KERNEL);
+	if (ret) {
+		kfree(new_table);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	new_sg = new_table->sgl;
+	for_each_sg(table->sgl, sg, table->nents, i) {
+		memcpy(new_sg, sg, sizeof(*sg));
+		new_sg->dma_address = 0;
+		new_sg = sg_next(new_sg);
+	}
+
+	return new_table;
+}
+
+static void free_duped_table(struct sg_table *table)
+{
+	sg_free_table(table);
+	kfree(table);
+}
+
+struct ion_dma_buf_attachment {
+	struct device *dev;
+	struct sg_table *table;
+	struct list_head list;
+};
+
+static int ion_dma_buf_attach(struct dma_buf *dmabuf,
+			      struct dma_buf_attachment *attachment)
+{
+	struct ion_dma_buf_attachment *a;
+	struct sg_table *table;
+	struct ion_buffer *buffer = dmabuf->priv;
+
+	a = kzalloc(sizeof(*a), GFP_KERNEL);
+	if (!a)
+		return -ENOMEM;
+
+	table = dup_sg_table(buffer->sg_table);
+	if (IS_ERR(table)) {
+		kfree(a);
+		return -ENOMEM;
+	}
+
+	a->table = table;
+	a->dev = attachment->dev;
+	INIT_LIST_HEAD(&a->list);
+
+	attachment->priv = a;
+
+	mutex_lock(&buffer->lock);
+	list_add(&a->list, &buffer->attachments);
+	mutex_unlock(&buffer->lock);
+
+	return 0;
+}
+
+static void ion_dma_buf_detatch(struct dma_buf *dmabuf,
+				struct dma_buf_attachment *attachment)
+{
+	struct ion_dma_buf_attachment *a = attachment->priv;
+	struct ion_buffer *buffer = dmabuf->priv;
+
+	mutex_lock(&buffer->lock);
+	list_del(&a->list);
+	mutex_unlock(&buffer->lock);
+	free_duped_table(a->table);
+
+	kfree(a);
+}
+
+static struct sg_table *ion_dma_buf_map(struct dma_buf_attachment *attachment,
+					enum dma_data_direction direction)
+{
+	struct ion_dma_buf_attachment *a = attachment->priv;
+	struct sg_table *table;
+
+	table = a->table;
+
+	if (!dma_map_sg(attachment->dev, table->sgl, table->nents,
+			direction))
+		return ERR_PTR(-ENOMEM);
+
+	return table;
+}
+
+static void ion_dma_buf_unmap(struct dma_buf_attachment *attachment,
+			      struct sg_table *table,
+			      enum dma_data_direction direction)
+{
+	dma_unmap_sg(attachment->dev, table->sgl, table->nents, direction);
+}
+
+static int ion_dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+	struct ion_buffer *buffer = dmabuf->priv;
+	int ret = 0;
+
+	if (!buffer->heap->ops->map_user) {
+		pr_err("%s: this heap does not define a method for mapping to userspace\n",
+		       __func__);
+		return -EINVAL;
+	}
+
+	if (!(buffer->flags & ION_FLAG_CACHED))
+		vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
+
+	mutex_lock(&buffer->lock);
+	/* now map it to userspace */
+	ret = buffer->heap->ops->map_user(buffer->heap, buffer, vma);
+	mutex_unlock(&buffer->lock);
+
+	if (ret)
+		pr_err("%s: failure mapping buffer to userspace\n",
+		       __func__);
+
+	return ret;
+}
+
+static void ion_dma_buf_release(struct dma_buf *dmabuf)
+{
+	struct ion_buffer *buffer = dmabuf->priv;
+
+	ion_free(buffer);
+}
+
+static void *ion_dma_buf_kmap(struct dma_buf *dmabuf, unsigned long offset)
+{
+	struct ion_buffer *buffer = dmabuf->priv;
+
+	return buffer->vaddr + offset * PAGE_SIZE;
+}
+
+static int ion_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
+					enum dma_data_direction direction)
+{
+	struct ion_buffer *buffer = dmabuf->priv;
+	void *vaddr;
+	struct ion_dma_buf_attachment *a;
+	int ret = 0;
+
+	/*
+	 * TODO: Move this elsewhere because we don't always need a vaddr
+	 */
+	if (buffer->heap->ops->map_kernel) {
+		mutex_lock(&buffer->lock);
+		vaddr = ion_buffer_kmap_get(buffer);
+		if (IS_ERR(vaddr)) {
+			ret = PTR_ERR(vaddr);
+			goto unlock;
+		}
+		mutex_unlock(&buffer->lock);
+	}
+
+	mutex_lock(&buffer->lock);
+	list_for_each_entry(a, &buffer->attachments, list) {
+		dma_sync_sg_for_cpu(a->dev, a->table->sgl, a->table->nents,
+				    direction);
+	}
+
+unlock:
+	mutex_unlock(&buffer->lock);
+	return ret;
+}
+
+static int ion_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
+				      enum dma_data_direction direction)
+{
+	struct ion_buffer *buffer = dmabuf->priv;
+	struct ion_dma_buf_attachment *a;
+
+	if (buffer->heap->ops->map_kernel) {
+		mutex_lock(&buffer->lock);
+		ion_buffer_kmap_put(buffer);
+		mutex_unlock(&buffer->lock);
+	}
+
+	mutex_lock(&buffer->lock);
+	list_for_each_entry(a, &buffer->attachments, list) {
+		dma_sync_sg_for_device(a->dev, a->table->sgl, a->table->nents,
+				       direction);
+	}
+	mutex_unlock(&buffer->lock);
+
+	return 0;
+}
+
+static const struct dma_buf_ops dma_buf_ops = {
+	.map_dma_buf = ion_dma_buf_map,
+	.unmap_dma_buf = ion_dma_buf_unmap,
+	.mmap = ion_dma_buf_mmap,
+	.release = ion_dma_buf_release,
+	.attach = ion_dma_buf_attach,
+	.detach = ion_dma_buf_detatch,
+	.begin_cpu_access = ion_dma_buf_begin_cpu_access,
+	.end_cpu_access = ion_dma_buf_end_cpu_access,
+	.map = ion_dma_buf_kmap,
+};
+
+struct dma_buf *ion_dmabuf_alloc(struct ion_device *dev, size_t len,
+				 unsigned int heap_id_mask,
+				 unsigned int flags)
+{
+	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);
+
+	buffer = ion_buffer_alloc(dev, len, heap_id_mask, flags);
+	if (IS_ERR(buffer))
+		return ERR_CAST(buffer);
+
+	exp_info.ops = &dma_buf_ops;
+	exp_info.size = buffer->size;
+	exp_info.flags = O_RDWR;
+	exp_info.priv = buffer;
+
+	dmabuf = dma_buf_export(&exp_info);
+	if (IS_ERR(dmabuf))
+		ion_buffer_destroy(dev, buffer);
+
+	return dmabuf;
+}
diff --git a/drivers/staging/android/ion/ion_private.h b/drivers/staging/android/ion/ion_private.h
index e80692c885b4..b3c8b55788db 100644
--- a/drivers/staging/android/ion/ion_private.h
+++ b/drivers/staging/android/ion/ion_private.h
@@ -9,6 +9,7 @@
 #define _ION_PRIVATE_H
 
 #include <linux/dcache.h>
+#include <linux/dma-buf.h>
 #include <linux/miscdevice.h>
 #include <linux/mutex.h>
 #include <linux/plist.h>
@@ -40,8 +41,16 @@ 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 int 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);
 
+/* ion dmabuf allocator */
+extern struct dma_buf *ion_dmabuf_alloc(struct ion_device *dev, size_t len,
+					unsigned int heap_id_mask,
+					unsigned int flags);
+extern int ion_free(struct ion_buffer *buffer);
+
+
 #endif /* _ION_PRIVATE_H */
diff --git a/include/linux/ion.h b/include/linux/ion.h
index 7bec77d98224..66a694b875ca 100644
--- a/include/linux/ion.h
+++ b/include/linux/ion.h
@@ -10,8 +10,18 @@
 #include <linux/err.h>
 
 #ifdef CONFIG_ION
-/*
- * Allocates an ION buffer.
+
+
+/**
+ * ion_alloc - Allocates an ion buffer of given size from given heap
+ *
+ * @len:               size of the buffer to be allocated.
+ * @heap_id_mask:      a bitwise maks of heap ids to allocate from
+ * @flags:             ION_BUFFER_XXXX flags for the new buffer.
+ *
+ * The function exports a dma_buf object for the new ion buffer internally
+ * and returns that to the caller. So, the buffer is ready to be used by other
+ * drivers immediately. Returns ERR_PTR in case of failure.
  */
 struct dma_buf *ion_alloc(size_t len, unsigned int heap_id_mask,
 			  unsigned int flags);
@@ -22,5 +32,7 @@ static inline struct dma_buf *ion_alloc(size_t len, unsigned int heap_id_mask,
 {
 	return ERR_PTR(-ENOMEM);
 }
+
+
 #endif /* CONFIG_ION */
 #endif /* _ION_KERNEL_H */