android_kernel_xiaomi_sm8450/kernel/dma/ops_helpers.c
Greg Kroah-Hartman 9072e986bd Revert "ANDROID: Export functions to be used with dma_map_ops in modules"
The symbols exported by this commit were never used by external modules,
so just remove them as the exports are not needed (and cause merge
problems at times.)

Bug: 151050914
Bug: 203756332
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I926ad3cc732ec1db97fc4711962bc3902105dd25
2022-09-21 08:24:25 +00:00

94 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Helpers for DMA ops implementations. These generally rely on the fact that
* the allocated memory contains normal pages in the direct kernel mapping.
*/
#include <linux/dma-map-ops.h>
static struct page *dma_common_vaddr_to_page(void *cpu_addr)
{
if (is_vmalloc_addr(cpu_addr))
return vmalloc_to_page(cpu_addr);
return virt_to_page(cpu_addr);
}
/*
* Create scatter-list for the already allocated DMA buffer.
*/
int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
struct page *page = dma_common_vaddr_to_page(cpu_addr);
int ret;
ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
if (!ret)
sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
return ret;
}
/*
* Create userspace mapping for the DMA-coherent memory.
*/
int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
{
#ifdef CONFIG_MMU
unsigned long user_count = vma_pages(vma);
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long off = vma->vm_pgoff;
struct page *page = dma_common_vaddr_to_page(cpu_addr);
int ret = -ENXIO;
vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
if (off >= count || user_count > count - off)
return -ENXIO;
return remap_pfn_range(vma, vma->vm_start,
page_to_pfn(page) + vma->vm_pgoff,
user_count << PAGE_SHIFT, vma->vm_page_prot);
#else
return -ENXIO;
#endif /* CONFIG_MMU */
}
struct page *dma_common_alloc_pages(struct device *dev, size_t size,
dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
struct page *page;
page = dma_alloc_contiguous(dev, size, gfp);
if (!page)
page = alloc_pages_node(dev_to_node(dev), gfp, get_order(size));
if (!page)
return NULL;
*dma_handle = ops->map_page(dev, page, 0, size, dir,
DMA_ATTR_SKIP_CPU_SYNC);
if (*dma_handle == DMA_MAPPING_ERROR) {
dma_free_contiguous(dev, page, size);
return NULL;
}
memset(page_address(page), 0, size);
return page;
}
void dma_common_free_pages(struct device *dev, size_t size, struct page *page,
dma_addr_t dma_handle, enum dma_data_direction dir)
{
const struct dma_map_ops *ops = get_dma_ops(dev);
if (ops->unmap_page)
ops->unmap_page(dev, dma_handle, size, dir,
DMA_ATTR_SKIP_CPU_SYNC);
dma_free_contiguous(dev, page, size);
}