[PATCH v3 4/4] dma-buf: heaps: add chunk heap to dmabuf heaps

Minchan Kim
2021-01-13T01:22:06Z

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 driver is bound directly to a reserved_memory
node by following Rob Herring's suggestion in [1].

[1] https://lore.kernel.org/lkml/20191025225009.50305-2-john.stultz@linaro.org/T/#m3dc63acd33fea269a584f43bb799a876f0b2b45d

Signed-off-by: Hyesoo Yu <hyesoo.yu@samsung.com>
Signed-off-by: Hridya Valsaraju <hridya@google.com>
Signed-off-by: Minchan Kim <minchan@kernel.org>
---
drivers/dma-buf/heaps/Kconfig | 8 +
drivers/dma-buf/heaps/Makefile | 1 +
drivers/dma-buf/heaps/chunk_heap.c | 477 +++++++++++++++++++++++++++++
3 files changed, 486 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..6527233f52a8 100644
--- a/drivers/dma-buf/heaps/Kconfig
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -12,3 +12,11 @@ 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
+ bool "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.
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..64f748c81e1f
--- /dev/null
+++ b/drivers/dma-buf/heaps/chunk_heap.c
@@ -0,0 +1,477 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMA-BUF chunk heap exporter
+ *
+ * Copyright (c) 2020 Samsung Electronics Co., Ltd.
+ * Author: <hyesoo.yu@samsung.com> for Samsung Electronics.
+ */
+
+#include <linux/cma.h>
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-heap.h>
+#include <linux/dma-mapping.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/of.h>
+#include <linux/of_fdt.h>
+#include <linux/of_reserved_mem.h>
+#include <linux/scatterlist.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+
+struct chunk_heap {
+ struct dma_heap *heap;
+ uint32_t 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;
+};
+
+struct chunk_heap chunk_heaps[MAX_CMA_AREAS];
+unsigned int chunk_heap_count;
+
+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;
+
+ 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;
+
+ if (a->mapped)
+ return table;
+
+ 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;
+ void *vaddr;
+
+ mutex_lock(&buffer->lock);
+ if (buffer->vmap_cnt) {
+ vaddr = buffer->vaddr;
+ } else {
+ vaddr = chunk_heap_do_vmap(buffer);
+ if (IS_ERR(vaddr)) {
+ mutex_unlock(&buffer->lock);
+
+ return PTR_ERR(vaddr);
+ }
+ buffer->vaddr = vaddr;
+ }
+ buffer->vmap_cnt++;
+ dma_buf_map_set_vaddr(map, vaddr);
+
+ mutex_unlock(&buffer->lock);
+
+ return 0;
+}
+
+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 alloc_order = max_t(unsigned int, pageblock_order, chunk_heap->order);
+ unsigned int nr_chunks_per_alloc = 1 << (alloc_order - chunk_heap->order);
+ gfp_t gfp_flags = GFP_KERNEL|__GFP_NORETRY;
+ 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 (alloced < count) {
+ struct page *page;
+ int i;
+
+ while (count - alloced < nr_chunks_per_alloc) {
+ alloc_order--;
+ nr_chunks_per_alloc >>= 1;
+ }
+
+ page = cma_alloc(chunk_heap->cma, 1 << alloc_order,
+ alloc_order, gfp_flags);
+ if (!page) {
+ if (gfp_flags & __GFP_NORETRY) {
+ gfp_flags &= ~__GFP_NORETRY;
+ continue;
+ }
+ break;
+ }
+
+ for (i = 0; i < nr_chunks_per_alloc; i++, alloced++) {
+ pages[alloced] = page;
+ page += 1 << chunk_heap->order;
+ }
+ }
+
+ if (alloced < count)
+ 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,
+};
+
+static int register_chunk_heap(struct chunk_heap *chunk_heap_info)
+{
+ struct dma_heap_export_info exp_info;
+
+ exp_info.name = cma_get_name(chunk_heap_info->cma);
+ exp_info.ops = &chunk_heap_ops;
+ exp_info.priv = chunk_heap_info;
+
+ chunk_heap_info->heap = dma_heap_add(&exp_info);
+ if (IS_ERR(chunk_heap_info->heap))
+ return PTR_ERR(chunk_heap_info->heap);
+
+ return 0;
+}
+
+static int __init chunk_heap_init(void)
+{
+ unsigned int i;
+
+ for (i = 0; i < chunk_heap_count; i++)
+ register_chunk_heap(&chunk_heaps[i]);
+
+ return 0;
+}
+module_init(chunk_heap_init);
+
+#ifdef CONFIG_OF_EARLY_FLATTREE
+
+static int __init dmabuf_chunk_heap_area_init(struct reserved_mem *rmem)
+{
+ int ret;
+ struct cma *cma;
+ struct chunk_heap *chunk_heap_info;
+ const __be32 *chunk_order;
+
+ phys_addr_t align = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order);
+ phys_addr_t mask = align - 1;
+
+ if ((rmem->base & mask) || (rmem->size & mask)) {
+ pr_err("Incorrect alignment for CMA region\n");
+ return -EINVAL;
+ }
+
+ ret = cma_init_reserved_mem(rmem->base, rmem->size, 0, rmem->name, &cma);
+ if (ret) {
+ pr_err("Reserved memory: unable to setup CMA region\n");
+ return ret;
+ }
+
+ /* Architecture specific contiguous memory fixup. */
+ dma_contiguous_early_fixup(rmem->base, rmem->size);
+
+ chunk_heap_info = &chunk_heaps[chunk_heap_count];
+ chunk_heap_info->cma = cma;
+
+ chunk_order = of_get_flat_dt_prop(rmem->fdt_node, "chunk-order", NULL);
+
+ if (chunk_order)
+ chunk_heap_info->order = be32_to_cpu(*chunk_order);
+ else
+ chunk_heap_info->order = 4;
+
+ chunk_heap_count++;
+
+ return 0;
+}
+RESERVEDMEM_OF_DECLARE(dmabuf_chunk_heap, "dma_heap,chunk",
+ dmabuf_chunk_heap_area_init);
+#endif
+
+MODULE_DESCRIPTION("DMA-BUF Chunk Heap");
+MODULE_LICENSE("GPL v2");
--
2.30.0.284.gd98b1dd5eaa7-goog