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Sender: Minchan Kim <minchan.kim@gmail.com>
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        Minchan Kim <minchan@kernel.org>
Subject: [PATCH 3/4] dma-buf: heaps: add chunk heap to dmabuf heaps
Date:   Tue, 17 Nov 2020 10:19:34 -0800
Message-Id: <20201117181935.3613581-4-minchan@kernel.org>
In-Reply-To: <20201117181935.3613581-1-minchan@kernel.org>
References: <20201117181935.3613581-1-minchan@kernel.org>
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From: Hyesoo Yu <hyesoo.yu@samsung.com>

This patch supports chunk heap that allocates the buffers that are
made up of a list of fixed size chunks taken from a CMA.

The chunk heap doesn't use heap-helper although it can remove
duplicated code since heap-helper is under deprecated process.[1]

[1] https://lore.kernel.org/patchwork/patch/1336002

Signed-off-by: Hyesoo Yu <hyesoo.yu@samsung.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
 drivers/dma-buf/heaps/Kconfig      |   9 +
 drivers/dma-buf/heaps/Makefile     |   1 +
 drivers/dma-buf/heaps/chunk_heap.c | 458 +++++++++++++++++++++++++++++
 3 files changed, 468 insertions(+)
 create mode 100644 drivers/dma-buf/heaps/chunk_heap.c

diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
index a5eef06c4226..9cc5366b8f5e 100644
--- a/drivers/dma-buf/heaps/Kconfig
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -12,3 +12,12 @@ config DMABUF_HEAPS_CMA
 	  Choose this option to enable dma-buf CMA heap. This heap is backed
 	  by the Contiguous Memory Allocator (CMA). If your system has these
 	  regions, you should say Y here.
+
+config DMABUF_HEAPS_CHUNK
+	tristate "DMA-BUF CHUNK Heap"
+	depends on DMABUF_HEAPS && DMA_CMA
+	help
+	  Choose this option to enable dma-buf CHUNK heap. This heap is backed
+	  by the Contiguous Memory Allocator (CMA) and allocates the buffers that
+	  arranged into a list of fixed size chunks taken from CMA. Chunk size
+	  is configured when the heap is created.
diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
index 6e54cdec3da0..3b2a09869fd8 100644
--- a/drivers/dma-buf/heaps/Makefile
+++ b/drivers/dma-buf/heaps/Makefile
@@ -2,3 +2,4 @@
 obj-y					+= heap-helpers.o
 obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)	+= system_heap.o
 obj-$(CONFIG_DMABUF_HEAPS_CMA)		+= cma_heap.o
+obj-$(CONFIG_DMABUF_HEAPS_CHUNK)	+= chunk_heap.o
diff --git a/drivers/dma-buf/heaps/chunk_heap.c b/drivers/dma-buf/heaps/chunk_heap.c
new file mode 100644
index 000000000000..427594f56e18
--- /dev/null
+++ b/drivers/dma-buf/heaps/chunk_heap.c
@@ -0,0 +1,458 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ION Memory Allocator chunk heap exporter
+ *
+ * Copyright (c) 2020 Samsung Electronics Co., Ltd.
+ * Author: <hyesoo.yu@samsung.com> for Samsung Electronics.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/cma.h>
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-heap.h>
+#include <linux/dma-map-ops.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/highmem.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/scatterlist.h>
+#include <linux/sched/signal.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/of.h>
+
+struct chunk_heap {
+	struct dma_heap *heap;
+	unsigned int order;
+	struct cma *cma;
+};
+
+struct chunk_heap_buffer {
+	struct chunk_heap *heap;
+	struct list_head attachments;
+	struct mutex lock;
+	struct sg_table sg_table;
+	unsigned long len;
+	int vmap_cnt;
+	void *vaddr;
+};
+
+struct chunk_heap_attachment {
+	struct device *dev;
+	struct sg_table *table;
+	struct list_head list;
+	bool mapped;
+};
+
+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->orig_nents, GFP_KERNEL);
+	if (ret) {
+		kfree(new_table);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	new_sg = new_table->sgl;
+	for_each_sgtable_sg(table, sg, i) {
+		sg_set_page(new_sg, sg_page(sg), sg->length, sg->offset);
+		new_sg = sg_next(new_sg);
+	}
+
+	return new_table;
+}
+
+static int chunk_heap_attach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment)
+{
+	struct chunk_heap_buffer *buffer = dmabuf->priv;
+	struct chunk_heap_attachment *a;
+	struct sg_table *table;
+
+	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);
+	a->mapped = false;
+
+	attachment->priv = a;
+
+	mutex_lock(&buffer->lock);
+	list_add(&a->list, &buffer->attachments);
+	mutex_unlock(&buffer->lock);
+
+	return 0;
+}
+
+static void chunk_heap_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment)
+{
+	struct chunk_heap_buffer *buffer = dmabuf->priv;
+	struct chunk_heap_attachment *a = attachment->priv;
+
+	mutex_lock(&buffer->lock);
+	list_del(&a->list);
+	mutex_unlock(&buffer->lock);
+
+	sg_free_table(a->table);
+	kfree(a->table);
+	kfree(a);
+}
+
+static struct sg_table *chunk_heap_map_dma_buf(struct dma_buf_attachment *attachment,
+					       enum dma_data_direction direction)
+{
+	struct chunk_heap_attachment *a = attachment->priv;
+	struct sg_table *table = a->table;
+	int ret;
+
+	ret = dma_map_sgtable(attachment->dev, table, direction, 0);
+	if (ret)
+		return ERR_PTR(ret);
+
+	a->mapped = true;
+	return table;
+}
+
+static void chunk_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
+				     struct sg_table *table,
+				     enum dma_data_direction direction)
+{
+	struct chunk_heap_attachment *a = attachment->priv;
+
+	a->mapped = false;
+	dma_unmap_sgtable(attachment->dev, table, direction, 0);
+}
+
+static int chunk_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
+						enum dma_data_direction direction)
+{
+	struct chunk_heap_buffer *buffer = dmabuf->priv;
+	struct chunk_heap_attachment *a;
+
+	mutex_lock(&buffer->lock);
+
+	if (buffer->vmap_cnt)
+		invalidate_kernel_vmap_range(buffer->vaddr, buffer->len);
+
+	list_for_each_entry(a, &buffer->attachments, list) {
+		if (!a->mapped)
+			continue;
+		dma_sync_sgtable_for_cpu(a->dev, a->table, direction);
+	}
+	mutex_unlock(&buffer->lock);
+
+	return 0;
+}
+
+static int chunk_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
+					      enum dma_data_direction direction)
+{
+	struct chunk_heap_buffer *buffer = dmabuf->priv;
+	struct chunk_heap_attachment *a;
+
+	mutex_lock(&buffer->lock);
+
+	if (buffer->vmap_cnt)
+		flush_kernel_vmap_range(buffer->vaddr, buffer->len);
+
+	list_for_each_entry(a, &buffer->attachments, list) {
+		if (!a->mapped)
+			continue;
+		dma_sync_sgtable_for_device(a->dev, a->table, direction);
+	}
+	mutex_unlock(&buffer->lock);
+
+	return 0;
+}
+
+static int chunk_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+	struct chunk_heap_buffer *buffer = dmabuf->priv;
+	struct sg_table *table = &buffer->sg_table;
+	unsigned long addr = vma->vm_start;
+	struct sg_page_iter piter;
+	int ret;
+
+	for_each_sgtable_page(table, &piter, vma->vm_pgoff) {
+		struct page *page = sg_page_iter_page(&piter);
+
+		ret = remap_pfn_range(vma, addr, page_to_pfn(page), PAGE_SIZE,
+				      vma->vm_page_prot);
+		if (ret)
+			return ret;
+		addr = PAGE_SIZE;
+		if (addr >= vma->vm_end)
+			return 0;
+	}
+	return 0;
+}
+
+static void *chunk_heap_do_vmap(struct chunk_heap_buffer *buffer)
+{
+	struct sg_table *table = &buffer->sg_table;
+	int npages = PAGE_ALIGN(buffer->len) / PAGE_SIZE;
+	struct page **pages = vmalloc(sizeof(struct page *) * npages);
+	struct page **tmp = pages;
+	struct sg_page_iter piter;
+	void *vaddr;
+
+	if (!pages)
+		return ERR_PTR(-ENOMEM);
+
+	for_each_sgtable_page(table, &piter, 0) {
+		WARN_ON(tmp - pages >= npages);
+		*tmp++ = sg_page_iter_page(&piter);
+	}
+
+	vaddr = vmap(pages, npages, VM_MAP, PAGE_KERNEL);
+	vfree(pages);
+
+	if (!vaddr)
+		return ERR_PTR(-ENOMEM);
+
+	return vaddr;
+}
+
+static int chunk_heap_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
+{
+	struct chunk_heap_buffer *buffer = dmabuf->priv;
+	int ret = 0;
+	void *vaddr;
+
+	mutex_lock(&buffer->lock);
+	if (buffer->vmap_cnt) {
+		vaddr = buffer->vaddr;
+		goto done;
+	}
+
+	vaddr = chunk_heap_do_vmap(buffer);
+	if (IS_ERR(vaddr)) {
+		ret = PTR_ERR(vaddr);
+		goto err;
+	}
+
+	buffer->vaddr = vaddr;
+done:
+	buffer->vmap_cnt++;
+	dma_buf_map_set_vaddr(map, vaddr);
+err:
+	mutex_unlock(&buffer->lock);
+
+	return ret;
+}
+
+static void chunk_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
+{
+	struct chunk_heap_buffer *buffer = dmabuf->priv;
+
+	mutex_lock(&buffer->lock);
+	if (!--buffer->vmap_cnt) {
+		vunmap(buffer->vaddr);
+		buffer->vaddr = NULL;
+	}
+	mutex_unlock(&buffer->lock);
+}
+
+static void chunk_heap_dma_buf_release(struct dma_buf *dmabuf)
+{
+	struct chunk_heap_buffer *buffer = dmabuf->priv;
+	struct chunk_heap *chunk_heap = buffer->heap;
+	struct sg_table *table;
+	struct scatterlist *sg;
+	int i;
+
+	table = &buffer->sg_table;
+	for_each_sgtable_sg(table, sg, i)
+		cma_release(chunk_heap->cma, sg_page(sg), 1 << chunk_heap->order);
+	sg_free_table(table);
+	kfree(buffer);
+}
+
+static const struct dma_buf_ops chunk_heap_buf_ops = {
+	.attach = chunk_heap_attach,
+	.detach = chunk_heap_detach,
+	.map_dma_buf = chunk_heap_map_dma_buf,
+	.unmap_dma_buf = chunk_heap_unmap_dma_buf,
+	.begin_cpu_access = chunk_heap_dma_buf_begin_cpu_access,
+	.end_cpu_access = chunk_heap_dma_buf_end_cpu_access,
+	.mmap = chunk_heap_mmap,
+	.vmap = chunk_heap_vmap,
+	.vunmap = chunk_heap_vunmap,
+	.release = chunk_heap_dma_buf_release,
+};
+
+static int chunk_heap_allocate(struct dma_heap *heap, unsigned long len,
+			       unsigned long fd_flags, unsigned long heap_flags)
+{
+	struct chunk_heap *chunk_heap = dma_heap_get_drvdata(heap);
+	struct chunk_heap_buffer *buffer;
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+	struct dma_buf *dmabuf;
+	struct sg_table *table;
+	struct scatterlist *sg;
+	struct page **pages;
+	unsigned int chunk_size = PAGE_SIZE << chunk_heap->order;
+	unsigned int count, alloced = 0;
+	unsigned int num_retry = 5;
+	int ret = -ENOMEM;
+	pgoff_t pg;
+
+	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
+	if (!buffer)
+		return ret;
+
+	INIT_LIST_HEAD(&buffer->attachments);
+	mutex_init(&buffer->lock);
+	buffer->heap = chunk_heap;
+	buffer->len = ALIGN(len, chunk_size);
+	count = buffer->len / chunk_size;
+
+	pages = kvmalloc_array(count, sizeof(*pages), GFP_KERNEL);
+	if (!pages)
+		goto err_pages;
+
+	while (num_retry--) {
+		unsigned long nr_pages;
+
+		ret = cma_alloc_bulk(chunk_heap->cma, chunk_heap->order,
+				     num_retry ? __GFP_NORETRY : 0,
+				     chunk_heap->order, count - alloced,
+				     pages + alloced, &nr_pages);
+		alloced += nr_pages;
+		if (alloced == count)
+			break;
+		if (ret != -EBUSY)
+			break;
+
+	}
+	if (ret < 0)
+		goto err_alloc;
+
+	table = &buffer->sg_table;
+	if (sg_alloc_table(table, count, GFP_KERNEL))
+		goto err_alloc;
+
+	sg = table->sgl;
+	for (pg = 0; pg < count; pg++) {
+		sg_set_page(sg, pages[pg], chunk_size, 0);
+		sg = sg_next(sg);
+	}
+
+	exp_info.ops = &chunk_heap_buf_ops;
+	exp_info.size = buffer->len;
+	exp_info.flags = fd_flags;
+	exp_info.priv = buffer;
+	dmabuf = dma_buf_export(&exp_info);
+	if (IS_ERR(dmabuf)) {
+		ret = PTR_ERR(dmabuf);
+		goto err_export;
+	}
+	kvfree(pages);
+
+	ret = dma_buf_fd(dmabuf, fd_flags);
+	if (ret < 0) {
+		dma_buf_put(dmabuf);
+		return ret;
+	}
+
+	return 0;
+err_export:
+	sg_free_table(table);
+err_alloc:
+	for (pg = 0; pg < alloced; pg++)
+		cma_release(chunk_heap->cma, pages[pg], 1 << chunk_heap->order);
+	kvfree(pages);
+err_pages:
+	kfree(buffer);
+
+	return ret;
+}
+
+static void rmem_remove_callback(void *p)
+{
+	of_reserved_mem_device_release((struct device *)p);
+}
+
+static const struct dma_heap_ops chunk_heap_ops = {
+	.allocate = chunk_heap_allocate,
+};
+
+static int chunk_heap_probe(struct platform_device *pdev)
+{
+	struct chunk_heap *chunk_heap;
+	struct dma_heap_export_info exp_info;
+	unsigned int alignment;
+	int ret;
+
+	ret = of_reserved_mem_device_init(&pdev->dev);
+	if (ret || !pdev->dev.cma_area) {
+		dev_err(&pdev->dev, "The CMA reserved area is not assigned (ret %d)", ret);
+		return -EINVAL;
+	}
+
+	ret = devm_add_action(&pdev->dev, rmem_remove_callback, &pdev->dev);
+	if (ret) {
+		of_reserved_mem_device_release(&pdev->dev);
+		return ret;
+	}
+
+	chunk_heap = devm_kzalloc(&pdev->dev, sizeof(*chunk_heap), GFP_KERNEL);
+	if (!chunk_heap)
+		return -ENOMEM;
+
+	if (of_property_read_u32(pdev->dev.of_node, "alignment", &alignment))
+		chunk_heap->order = 0;
+	else
+		chunk_heap->order = get_order(alignment);
+
+	chunk_heap->cma = pdev->dev.cma_area;
+
+	exp_info.name = cma_get_name(pdev->dev.cma_area);
+	exp_info.ops = &chunk_heap_ops;
+	exp_info.priv = chunk_heap;
+
+	chunk_heap->heap = dma_heap_add(&exp_info);
+	if (IS_ERR(chunk_heap->heap))
+		return PTR_ERR(chunk_heap->heap);
+
+	return 0;
+}
+
+static const struct of_device_id chunk_heap_of_match[] = {
+	{ .compatible = "dma_heap,chunk", },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(of, chunk_heap_of_match);
+
+static struct platform_driver chunk_heap_driver = {
+	.driver		= {
+		.name	= "chunk_heap",
+		.of_match_table = chunk_heap_of_match,
+	},
+	.probe		= chunk_heap_probe,
+};
+
+static int __init chunk_heap_init(void)
+{
+	return platform_driver_register(&chunk_heap_driver);
+}
+module_init(chunk_heap_init);
+MODULE_DESCRIPTION("DMA-BUF Chunk Heap");
+MODULE_LICENSE("GPL v2");
-- 
2.29.2.299.gdc1121823c-goog