1 files changed, 367 insertions, 47 deletions

diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index 0bf688e3c023..17e0e9a68baf 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -3,7 +3,11 @@
  * DMABUF System heap exporter
  *
  * Copyright (C) 2011 Google, Inc.
- * Copyright (C) 2019 Linaro Ltd.
+ * Copyright (C) 2019, 2020 Linaro Ltd.
+ *
+ * Portions based off of Andrew Davis' SRAM heap:
+ * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com/
+ *	Andrew F. Davis <afd@ti.com>
  */
 
 #include <linux/dma-buf.h>
@@ -15,87 +19,404 @@
 #include <linux/module.h>
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
-#include <linux/sched/signal.h>
-#include <asm/page.h>
+#include <linux/vmalloc.h>
+
+static struct dma_heap *sys_heap;
+
+struct system_heap_buffer {
+	struct dma_heap *heap;
+	struct list_head attachments;
+	struct mutex lock;
+	unsigned long len;
+	struct sg_table sg_table;
+	int vmap_cnt;
+	void *vaddr;
+};
+
+struct dma_heap_attachment {
+	struct device *dev;
+	struct sg_table *table;
+	struct list_head list;
+	bool mapped;
+};
+
+#define HIGH_ORDER_GFP  (((GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN \
+				| __GFP_NORETRY) & ~__GFP_RECLAIM) \
+				| __GFP_COMP)
+#define LOW_ORDER_GFP (GFP_HIGHUSER | __GFP_ZERO | __GFP_COMP)
+static gfp_t order_flags[] = {HIGH_ORDER_GFP, LOW_ORDER_GFP, LOW_ORDER_GFP};
+/*
+ * The selection of the orders used for allocation (1MB, 64K, 4K) is designed
+ * to match with the sizes often found in IOMMUs. Using order 4 pages instead
+ * of order 0 pages can significantly improve the performance of many IOMMUs
+ * by reducing TLB pressure and time spent updating page tables.
+ */
+static const unsigned int orders[] = {8, 4, 0};
+#define NUM_ORDERS ARRAY_SIZE(orders)
+
+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 system_heap_attach(struct dma_buf *dmabuf,
+			      struct dma_buf_attachment *attachment)
+{
+	struct system_heap_buffer *buffer = dmabuf->priv;
+	struct dma_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 system_heap_detach(struct dma_buf *dmabuf,
+			       struct dma_buf_attachment *attachment)
+{
+	struct system_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->table);
+	kfree(a);
+}
+
+static struct sg_table *system_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(ret);
+
+	a->mapped = true;
+	return table;
+}
+
+static void system_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 system_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
+						enum dma_data_direction direction)
+{
+	struct system_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 system_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
+					      enum dma_data_direction direction)
+{
+	struct system_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);
 
-#include "heap-helpers.h"
+	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 system_heap_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+	struct system_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 *system_heap_do_vmap(struct system_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 system_heap_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
+{
+	struct system_heap_buffer *buffer = dmabuf->priv;
+	void *vaddr;
+	int ret = 0;
+
+	mutex_lock(&buffer->lock);
+	if (buffer->vmap_cnt) {
+		buffer->vmap_cnt++;
+		dma_buf_map_set_vaddr(map, buffer->vaddr);
+		goto out;
+	}
+
+	vaddr = system_heap_do_vmap(buffer);
+	if (IS_ERR(vaddr)) {
+		ret = PTR_ERR(vaddr);
+		goto out;
+	}
+
+	buffer->vaddr = vaddr;
+	buffer->vmap_cnt++;
+	dma_buf_map_set_vaddr(map, buffer->vaddr);
+out:
+	mutex_unlock(&buffer->lock);
+
+	return ret;
+}
 
-struct dma_heap *sys_heap;
+static void system_heap_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
+{
+	struct system_heap_buffer *buffer = dmabuf->priv;
 
-static void system_heap_free(struct heap_helper_buffer *buffer)
+	mutex_lock(&buffer->lock);
+	if (!--buffer->vmap_cnt) {
+		vunmap(buffer->vaddr);
+		buffer->vaddr = NULL;
+	}
+	mutex_unlock(&buffer->lock);
+	dma_buf_map_clear(map);
+}
+
+static void system_heap_dma_buf_release(struct dma_buf *dmabuf)
 {
-	pgoff_t pg;
+	struct system_heap_buffer *buffer = dmabuf->priv;
+	struct sg_table *table;
+	struct scatterlist *sg;
+	int i;
+
+	table = &buffer->sg_table;
+	for_each_sg(table->sgl, sg, table->nents, i) {
+		struct page *page = sg_page(sg);
 
-	for (pg = 0; pg < buffer->pagecount; pg++)
-		__free_page(buffer->pages[pg]);
-	kfree(buffer->pages);
+		__free_pages(page, compound_order(page));
+	}
+	sg_free_table(table);
 	kfree(buffer);
 }
 
+static const struct dma_buf_ops system_heap_buf_ops = {
+	.attach = system_heap_attach,
+	.detach = system_heap_detach,
+	.map_dma_buf = system_heap_map_dma_buf,
+	.unmap_dma_buf = system_heap_unmap_dma_buf,
+	.begin_cpu_access = system_heap_dma_buf_begin_cpu_access,
+	.end_cpu_access = system_heap_dma_buf_end_cpu_access,
+	.mmap = system_heap_mmap,
+	.vmap = system_heap_vmap,
+	.vunmap = system_heap_vunmap,
+	.release = system_heap_dma_buf_release,
+};
+
+static struct page *alloc_largest_available(unsigned long size,
+					    unsigned int max_order)
+{
+	struct page *page;
+	int i;
+
+	for (i = 0; i < NUM_ORDERS; i++) {
+		if (size <  (PAGE_SIZE << orders[i]))
+			continue;
+		if (max_order < orders[i])
+			continue;
+
+		page = alloc_pages(order_flags[i], orders[i]);
+		if (!page)
+			continue;
+		return page;
+	}
+	return NULL;
+}
+
 static int system_heap_allocate(struct dma_heap *heap,
 				unsigned long len,
 				unsigned long fd_flags,
 				unsigned long heap_flags)
 {
-	struct heap_helper_buffer *helper_buffer;
+	struct system_heap_buffer *buffer;
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+	unsigned long size_remaining = len;
+	unsigned int max_order = orders[0];
 	struct dma_buf *dmabuf;
-	int ret = -ENOMEM;
-	pgoff_t pg;
+	struct sg_table *table;
+	struct scatterlist *sg;
+	struct list_head pages;
+	struct page *page, *tmp_page;
+	int i, ret = -ENOMEM;
 
-	helper_buffer = kzalloc(sizeof(*helper_buffer), GFP_KERNEL);
-	if (!helper_buffer)
+	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
+	if (!buffer)
 		return -ENOMEM;
 
-	init_heap_helper_buffer(helper_buffer, system_heap_free);
-	helper_buffer->heap = heap;
-	helper_buffer->size = len;
-
-	helper_buffer->pagecount = len / PAGE_SIZE;
-	helper_buffer->pages = kmalloc_array(helper_buffer->pagecount,
-					     sizeof(*helper_buffer->pages),
-					     GFP_KERNEL);
-	if (!helper_buffer->pages) {
-		ret = -ENOMEM;
-		goto err0;
-	}
+	INIT_LIST_HEAD(&buffer->attachments);
+	mutex_init(&buffer->lock);
+	buffer->heap = heap;
+	buffer->len = len;
 
-	for (pg = 0; pg < helper_buffer->pagecount; pg++) {
+	INIT_LIST_HEAD(&pages);
+	i = 0;
+	while (size_remaining > 0) {
 		/*
 		 * Avoid trying to allocate memory if the process
-		 * has been killed by by SIGKILL
+		 * has been killed by SIGKILL
 		 */
 		if (fatal_signal_pending(current))
-			goto err1;
+			goto free_buffer;
+
+		page = alloc_largest_available(size_remaining, max_order);
+		if (!page)
+			goto free_buffer;
+
+		list_add_tail(&page->lru, &pages);
+		size_remaining -= page_size(page);
+		max_order = compound_order(page);
+		i++;
+	}
+
+	table = &buffer->sg_table;
+	if (sg_alloc_table(table, i, GFP_KERNEL))
+		goto free_buffer;
 
-		helper_buffer->pages[pg] = alloc_page(GFP_KERNEL | __GFP_ZERO);
-		if (!helper_buffer->pages[pg])
-			goto err1;
+	sg = table->sgl;
+	list_for_each_entry_safe(page, tmp_page, &pages, lru) {
+		sg_set_page(sg, page, page_size(page), 0);
+		sg = sg_next(sg);
+		list_del(&page->lru);
 	}
 
 	/* create the dmabuf */
-	dmabuf = heap_helper_export_dmabuf(helper_buffer, fd_flags);
+	exp_info.ops = &system_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 err1;
+		goto free_pages;
 	}
 
-	helper_buffer->dmabuf = dmabuf;
-
 	ret = dma_buf_fd(dmabuf, fd_flags);
 	if (ret < 0) {
 		dma_buf_put(dmabuf);
 		/* just return, as put will call release and that will free */
 		return ret;
 	}
-
 	return ret;
 
-err1:
-	while (pg > 0)
-		__free_page(helper_buffer->pages[--pg]);
-	kfree(helper_buffer->pages);
-err0:
-	kfree(helper_buffer);
+free_pages:
+	for_each_sgtable_sg(table, sg, i) {
+		struct page *p = sg_page(sg);
+
+		__free_pages(p, compound_order(p));
+	}
+	sg_free_table(table);
+free_buffer:
+	list_for_each_entry_safe(page, tmp_page, &pages, lru)
+		__free_pages(page, compound_order(page));
+	kfree(buffer);
 
 	return ret;
 }
@@ -107,7 +428,6 @@ static const struct dma_heap_ops system_heap_ops = {
 static int system_heap_create(void)
 {
 	struct dma_heap_export_info exp_info;
-	int ret = 0;
 
 	exp_info.name = "system";
 	exp_info.ops = &system_heap_ops;
@@ -115,9 +435,9 @@ static int system_heap_create(void)
 
 	sys_heap = dma_heap_add(&exp_info);
 	if (IS_ERR(sys_heap))
-		ret = PTR_ERR(sys_heap);
+		return PTR_ERR(sys_heap);
 
-	return ret;
+	return 0;
 }
 module_init(system_heap_create);
 MODULE_LICENSE("GPL v2");