diff options
Diffstat (limited to 'drivers/dma-buf/heaps')
| -rw-r--r-- | drivers/dma-buf/heaps/Kconfig | 14 | ||||
| -rw-r--r-- | drivers/dma-buf/heaps/Makefile | 3 | ||||
| -rw-r--r-- | drivers/dma-buf/heaps/cma_heap.c | 407 | ||||
| -rw-r--r-- | drivers/dma-buf/heaps/system_heap.c | 440 |
4 files changed, 864 insertions, 0 deletions
diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig new file mode 100644 index 000000000..a5eef06c4 --- /dev/null +++ b/drivers/dma-buf/heaps/Kconfig @@ -0,0 +1,14 @@ +config DMABUF_HEAPS_SYSTEM + bool "DMA-BUF System Heap" + depends on DMABUF_HEAPS + help + Choose this option to enable the system dmabuf heap. The system heap + is backed by pages from the buddy allocator. If in doubt, say Y. + +config DMABUF_HEAPS_CMA + bool "DMA-BUF CMA Heap" + depends on DMABUF_HEAPS && DMA_CMA + help + 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. diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile new file mode 100644 index 000000000..974467791 --- /dev/null +++ b/drivers/dma-buf/heaps/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 +obj-$(CONFIG_DMABUF_HEAPS_SYSTEM) += system_heap.o +obj-$(CONFIG_DMABUF_HEAPS_CMA) += cma_heap.o 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"); diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c new file mode 100644 index 000000000..fcf836ba9 --- /dev/null +++ b/drivers/dma-buf/heaps/system_heap.c @@ -0,0 +1,440 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DMABUF System heap exporter + * + * Copyright (C) 2011 Google, Inc. + * 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> +#include <linux/dma-mapping.h> +#include <linux/dma-heap.h> +#include <linux/err.h> +#include <linux/highmem.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/scatterlist.h> +#include <linux/slab.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 LOW_ORDER_GFP (GFP_HIGHUSER | __GFP_ZERO | __GFP_COMP) +#define MID_ORDER_GFP (LOW_ORDER_GFP | __GFP_NOWARN) +#define HIGH_ORDER_GFP (((GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN \ + | __GFP_NORETRY) & ~__GFP_RECLAIM) \ + | __GFP_COMP) +static gfp_t order_flags[] = {HIGH_ORDER_GFP, MID_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); + + 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 iosys_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++; + iosys_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++; + iosys_map_set_vaddr(map, buffer->vaddr); +out: + mutex_unlock(&buffer->lock); + + return ret; +} + +static void system_heap_vunmap(struct dma_buf *dmabuf, struct iosys_map *map) +{ + struct system_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 system_heap_dma_buf_release(struct dma_buf *dmabuf) +{ + struct system_heap_buffer *buffer = dmabuf->priv; + struct sg_table *table; + struct scatterlist *sg; + int i; + + table = &buffer->sg_table; + for_each_sgtable_sg(table, sg, i) { + struct page *page = sg_page(sg); + + __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 struct dma_buf *system_heap_allocate(struct dma_heap *heap, + unsigned long len, + unsigned long fd_flags, + unsigned long heap_flags) +{ + 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; + struct sg_table *table; + struct scatterlist *sg; + struct list_head pages; + struct page *page, *tmp_page; + int i, ret = -ENOMEM; + + buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); + if (!buffer) + return ERR_PTR(-ENOMEM); + + INIT_LIST_HEAD(&buffer->attachments); + mutex_init(&buffer->lock); + buffer->heap = heap; + buffer->len = len; + + INIT_LIST_HEAD(&pages); + i = 0; + while (size_remaining > 0) { + /* + * Avoid trying to allocate memory if the process + * has been killed by SIGKILL + */ + if (fatal_signal_pending(current)) { + ret = -EINTR; + 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; + + 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 */ + exp_info.exp_name = dma_heap_get_name(heap); + 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 free_pages; + } + return dmabuf; + +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 ERR_PTR(ret); +} + +static const struct dma_heap_ops system_heap_ops = { + .allocate = system_heap_allocate, +}; + +static int system_heap_create(void) +{ + struct dma_heap_export_info exp_info; + + exp_info.name = "system"; + exp_info.ops = &system_heap_ops; + exp_info.priv = NULL; + + sys_heap = dma_heap_add(&exp_info); + if (IS_ERR(sys_heap)) + return PTR_ERR(sys_heap); + + return 0; +} +module_init(system_heap_create); +MODULE_LICENSE("GPL v2"); |