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Subject[PATCH v2 4/4] dma-buf: heaps: add chunk heap to dmabuf heaps
Date
From: Hyesoo Yu <hyesoo.yu@samsung.com>

This patch supports chunk heap that allocates the buffers that
arranged into a list a fixed size chunks taken from CMA.

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

NOTE: This patch only adds the default CMA heap to allocate chunk
pages. We will add another CMA memory regions to the dmabuf heaps
interface with a later patch (which requires a dt binding)

[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 | 15 +
drivers/dma-buf/heaps/Makefile | 1 +
drivers/dma-buf/heaps/chunk_heap.c | 429 +++++++++++++++++++++++++++++
3 files changed, 445 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..9153f83afed7 100644
--- a/drivers/dma-buf/heaps/Kconfig
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -12,3 +12,18 @@ 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.
+
+config DMABUF_HEAPS_CHUNK_ORDER
+ int "Chunk page order for dmabuf chunk heap"
+ default 4
+ depends on DMABUF_HEAPS_CHUNK
+ help
+ Set page order of fixed chunk size to allocate from CMA.
diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
index 974467791032..8faa6cfdc0c5 100644
--- a/drivers/dma-buf/heaps/Makefile
+++ b/drivers/dma-buf/heaps/Makefile
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
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..0277707a93a9
--- /dev/null
+++ b/drivers/dma-buf/heaps/chunk_heap.c
@@ -0,0 +1,429 @@
+// 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 ? true : false,
+ 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 const struct dma_heap_ops chunk_heap_ops = {
+ .allocate = chunk_heap_allocate,
+};
+
+#ifdef CONFIG_DMABUF_HEAPS_CHUNK_ORDER
+#define CHUNK_HEAP_ORDER (CONFIG_DMABUF_HEAPS_CHUNK_ORDER)
+#else
+#define CHUNK_HEAP_ORDER (0)
+#endif
+
+static int __init chunk_heap_init(void)
+{
+ struct cma *default_cma = dev_get_cma_area(NULL);
+ struct dma_heap_export_info exp_info;
+ struct chunk_heap *chunk_heap;
+
+ if (!default_cma)
+ return 0;
+
+ chunk_heap = kzalloc(sizeof(*chunk_heap), GFP_KERNEL);
+ if (!chunk_heap)
+ return -ENOMEM;
+
+ chunk_heap->order = CHUNK_HEAP_ORDER;
+ chunk_heap->cma = default_cma;
+
+ exp_info.name = cma_get_name(default_cma);
+ 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)) {
+ int ret = PTR_ERR(chunk_heap->heap);
+
+ kfree(chunk_heap);
+ return ret;
+ }
+
+ return 0;
+}
+module_init(chunk_heap_init);
+MODULE_DESCRIPTION("DMA-BUF Chunk Heap");
+MODULE_LICENSE("GPL v2");
--
2.29.2.454.gaff20da3a2-goog
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