1 files changed, 407 insertions, 0 deletions
diff --git a/drivers/dma-buf/heaps/cma_heap.c b/drivers/dma-buf/heaps/cma_heap.c
new file mode 100644
index 000000000..28fb04ecc
--- /dev/null
+++ b/drivers/dma-buf/heaps/cma_heap.c
@@ -0,0 +1,407 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMABUF CMA heap exporter
+ *
+ * Copyright (C) 2012, 2019, 2020 Linaro Ltd.
+ * Author: <benjamin.gaignard@linaro.org> for ST-Ericsson.
+ *
+ * Also utilizing parts of Andrew Davis' SRAM heap:
+ * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
+ *	Andrew F. Davis <afd@ti.com>
+ */
+#include <linux/cma.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-heap.h>
+#include <linux/dma-map-ops.h>
+#include <linux/err.h>
+#include <linux/highmem.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+
+struct cma_heap {
+	struct dma_heap *heap;
+	struct cma *cma;
+};
+
+struct cma_heap_buffer {
+	struct cma_heap *heap;
+	struct list_head attachments;
+	struct mutex lock;
+	unsigned long len;
+	struct page *cma_pages;
+	struct page **pages;
+	pgoff_t pagecount;
+	int vmap_cnt;
+	void *vaddr;
+};
+
+struct dma_heap_attachment {
+	struct device *dev;
+	struct sg_table table;
+	struct list_head list;
+	bool mapped;
+};
+
+static int cma_heap_attach(struct dma_buf *dmabuf,
+			   struct dma_buf_attachment *attachment)
+{
+	struct cma_heap_buffer *buffer = dmabuf->priv;
+	struct dma_heap_attachment *a;
+	int ret;
+
+	a = kzalloc(sizeof(*a), GFP_KERNEL);
+	if (!a)
+		return -ENOMEM;
+
+	ret = sg_alloc_table_from_pages(&a->table, buffer->pages,
+					buffer->pagecount, 0,
+					buffer->pagecount << PAGE_SHIFT,
+					GFP_KERNEL);
+	if (ret) {
+		kfree(a);
+		return ret;
+	}
+
+	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 cma_heap_detach(struct dma_buf *dmabuf,
+			    struct dma_buf_attachment *attachment)
+{
+	struct cma_heap_buffer *buffer = dmabuf->priv;
+	struct dma_heap_attachment *a = attachment->priv;
+
+	mutex_lock(&buffer->lock);
+	list_del(&a->list);
+	mutex_unlock(&buffer->lock);
+
+	sg_free_table(&a->table);
+	kfree(a);
+}
+
+static struct sg_table *cma_heap_map_dma_buf(struct dma_buf_attachment *attachment,
+					     enum dma_data_direction direction)
+{
+	struct dma_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(-ENOMEM);
+	a->mapped = true;
+	return table;
+}
+
+static void cma_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
+				   struct sg_table *table,
+				   enum dma_data_direction direction)
+{
+	struct dma_heap_attachment *a = attachment->priv;
+
+	a->mapped = false;
+	dma_unmap_sgtable(attachment->dev, table, direction, 0);
+}
+
+static int cma_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
+					     enum dma_data_direction direction)
+{
+	struct cma_heap_buffer *buffer = dmabuf->priv;
+	struct dma_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 cma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
+					   enum dma_data_direction direction)
+{
+	struct cma_heap_buffer *buffer = dmabuf->priv;
+	struct dma_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 vm_fault_t cma_heap_vm_fault(struct vm_fault *vmf)
+{
+	struct vm_area_struct *vma = vmf->vma;
+	struct cma_heap_buffer *buffer = vma->vm_private_data;
+
+	if (vmf->pgoff > buffer->pagecount)
+		return VM_FAULT_SIGBUS;
+
+	vmf->page = buffer->pages[vmf->pgoff];
+	get_page(vmf->page);
+
+	return 0;
+}
+
+static const struct vm_operations_struct dma_heap_vm_ops = {
+	.fault = cma_heap_vm_fault,
+};
+
+static int cma_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+	struct cma_heap_buffer *buffer = dmabuf->priv;
+
+	if ((vma->vm_flags & (VM_SHARED | VM_MAYSHARE)) == 0)
+		return -EINVAL;
+
+	vma->vm_ops = &dma_heap_vm_ops;
+	vma->vm_private_data = buffer;
+
+	return 0;
+}
+
+static void *cma_heap_do_vmap(struct cma_heap_buffer *buffer)
+{
+	void *vaddr;
+
+	vaddr = vmap(buffer->pages, buffer->pagecount, VM_MAP, PAGE_KERNEL);
+	if (!vaddr)
+		return ERR_PTR(-ENOMEM);
+
+	return vaddr;
+}
+
+static int cma_heap_vmap(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+	struct cma_heap_buffer *buffer = dmabuf->priv;
+	void *vaddr;
+	int ret = 0;
+
+	mutex_lock(&buffer->lock);
+	if (buffer->vmap_cnt) {
+		buffer->vmap_cnt++;
+		iosys_map_set_vaddr(map, buffer->vaddr);
+		goto out;
+	}
+
+	vaddr = cma_heap_do_vmap(buffer);
+	if (IS_ERR(vaddr)) {
+		ret = PTR_ERR(vaddr);
+		goto out;
+	}
+	buffer->vaddr = vaddr;
+	buffer->vmap_cnt++;
+	iosys_map_set_vaddr(map, buffer->vaddr);
+out:
+	mutex_unlock(&buffer->lock);
+
+	return ret;
+}
+
+static void cma_heap_vunmap(struct dma_buf *dmabuf, struct iosys_map *map)
+{
+	struct cma_heap_buffer *buffer = dmabuf->priv;
+
+	mutex_lock(&buffer->lock);
+	if (!--buffer->vmap_cnt) {
+		vunmap(buffer->vaddr);
+		buffer->vaddr = NULL;
+	}
+	mutex_unlock(&buffer->lock);
+	iosys_map_clear(map);
+}
+
+static void cma_heap_dma_buf_release(struct dma_buf *dmabuf)
+{
+	struct cma_heap_buffer *buffer = dmabuf->priv;
+	struct cma_heap *cma_heap = buffer->heap;
+
+	if (buffer->vmap_cnt > 0) {
+		WARN(1, "%s: buffer still mapped in the kernel\n", __func__);
+		vunmap(buffer->vaddr);
+		buffer->vaddr = NULL;
+	}
+
+	/* free page list */
+	kfree(buffer->pages);
+	/* release memory */
+	cma_release(cma_heap->cma, buffer->cma_pages, buffer->pagecount);
+	kfree(buffer);
+}
+
+static const struct dma_buf_ops cma_heap_buf_ops = {
+	.attach = cma_heap_attach,
+	.detach = cma_heap_detach,
+	.map_dma_buf = cma_heap_map_dma_buf,
+	.unmap_dma_buf = cma_heap_unmap_dma_buf,
+	.begin_cpu_access = cma_heap_dma_buf_begin_cpu_access,
+	.end_cpu_access = cma_heap_dma_buf_end_cpu_access,
+	.mmap = cma_heap_mmap,
+	.vmap = cma_heap_vmap,
+	.vunmap = cma_heap_vunmap,
+	.release = cma_heap_dma_buf_release,
+};
+
+static struct dma_buf *cma_heap_allocate(struct dma_heap *heap,
+					 unsigned long len,
+					 unsigned long fd_flags,
+					 unsigned long heap_flags)
+{
+	struct cma_heap *cma_heap = dma_heap_get_drvdata(heap);
+	struct cma_heap_buffer *buffer;
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+	size_t size = PAGE_ALIGN(len);
+	pgoff_t pagecount = size >> PAGE_SHIFT;
+	unsigned long align = get_order(size);
+	struct page *cma_pages;
+	struct dma_buf *dmabuf;
+	int ret = -ENOMEM;
+	pgoff_t pg;
+
+	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
+	if (!buffer)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&buffer->attachments);
+	mutex_init(&buffer->lock);
+	buffer->len = size;
+
+	if (align > CONFIG_CMA_ALIGNMENT)
+		align = CONFIG_CMA_ALIGNMENT;
+
+	cma_pages = cma_alloc(cma_heap->cma, pagecount, align, false);
+	if (!cma_pages)
+		goto free_buffer;
+
+	/* Clear the cma pages */
+	if (PageHighMem(cma_pages)) {
+		unsigned long nr_clear_pages = pagecount;
+		struct page *page = cma_pages;
+
+		while (nr_clear_pages > 0) {
+			void *vaddr = kmap_atomic(page);
+
+			memset(vaddr, 0, PAGE_SIZE);
+			kunmap_atomic(vaddr);
+			/*
+			 * Avoid wasting time zeroing memory if the process
+			 * has been killed by by SIGKILL
+			 */
+			if (fatal_signal_pending(current))
+				goto free_cma;
+			page++;
+			nr_clear_pages--;
+		}
+	} else {
+		memset(page_address(cma_pages), 0, size);
+	}
+
+	buffer->pages = kmalloc_array(pagecount, sizeof(*buffer->pages), GFP_KERNEL);
+	if (!buffer->pages) {
+		ret = -ENOMEM;
+		goto free_cma;
+	}
+
+	for (pg = 0; pg < pagecount; pg++)
+		buffer->pages[pg] = &cma_pages[pg];
+
+	buffer->cma_pages = cma_pages;
+	buffer->heap = cma_heap;
+	buffer->pagecount = pagecount;
+
+	/* create the dmabuf */
+	exp_info.exp_name = dma_heap_get_name(heap);
+	exp_info.ops = &cma_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 free_pages;
+	}
+	return dmabuf;
+
+free_pages:
+	kfree(buffer->pages);
+free_cma:
+	cma_release(cma_heap->cma, cma_pages, pagecount);
+free_buffer:
+	kfree(buffer);
+
+	return ERR_PTR(ret);
+}
+
+static const struct dma_heap_ops cma_heap_ops = {
+	.allocate = cma_heap_allocate,
+};
+
+static int __add_cma_heap(struct cma *cma, void *data)
+{
+	struct cma_heap *cma_heap;
+	struct dma_heap_export_info exp_info;
+
+	cma_heap = kzalloc(sizeof(*cma_heap), GFP_KERNEL);
+	if (!cma_heap)
+		return -ENOMEM;
+	cma_heap->cma = cma;
+
+	exp_info.name = cma_get_name(cma);
+	exp_info.ops = &cma_heap_ops;
+	exp_info.priv = cma_heap;
+
+	cma_heap->heap = dma_heap_add(&exp_info);
+	if (IS_ERR(cma_heap->heap)) {
+		int ret = PTR_ERR(cma_heap->heap);
+
+		kfree(cma_heap);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int add_default_cma_heap(void)
+{
+	struct cma *default_cma = dev_get_cma_area(NULL);
+	int ret = 0;
+
+	if (default_cma)
+		ret = __add_cma_heap(default_cma, NULL);
+
+	return ret;
+}
+module_init(add_default_cma_heap);
+MODULE_DESCRIPTION("DMA-BUF CMA Heap");
+MODULE_LICENSE("GPL v2");