This patch add simple allocator for CMA regions.
version 2: - fix size and page count computation
Signed-off-by: Benjamin Gaignard benjamin.gaignard@linaro.org --- drivers/simpleallocator/Kconfig | 7 + drivers/simpleallocator/Makefile | 1 + drivers/simpleallocator/simple-allocator-cma.c | 187 +++++++++++++++++++++++++ 3 files changed, 195 insertions(+) create mode 100644 drivers/simpleallocator/simple-allocator-cma.c
diff --git a/drivers/simpleallocator/Kconfig b/drivers/simpleallocator/Kconfig index c6fc2e3..788fb0b 100644 --- a/drivers/simpleallocator/Kconfig +++ b/drivers/simpleallocator/Kconfig @@ -7,4 +7,11 @@ config SIMPLE_ALLOCATOR The Simple Allocator Framework adds an API to allocate and share memory in userland.
+config SIMPLE_ALLOCATOR_CMA + tristate "Simple Allocator CMA" + select SIMPLE_ALLOCATOR + depends on DMA_CMA + ---help--- + Select this option to enable Simple Allocator on CMA area. + endmenu diff --git a/drivers/simpleallocator/Makefile b/drivers/simpleallocator/Makefile index e27c6ad..4e11611 100644 --- a/drivers/simpleallocator/Makefile +++ b/drivers/simpleallocator/Makefile @@ -1 +1,2 @@ obj-$(CONFIG_SIMPLE_ALLOCATOR) += simple-allocator.o +obj-$(CONFIG_SIMPLE_ALLOCATOR_CMA) += simple-allocator-cma.o diff --git a/drivers/simpleallocator/simple-allocator-cma.c b/drivers/simpleallocator/simple-allocator-cma.c new file mode 100644 index 0000000..07cbf5b --- /dev/null +++ b/drivers/simpleallocator/simple-allocator-cma.c @@ -0,0 +1,187 @@ +/* + * Copyright (C) Linaro 2017 + * + * Author: Benjamin Gaignard benjamin.gaignard@linaro.org + * + * License terms: GNU General Public License (GPL) + */ + +#include <linux/cma.h> +#include <linux/module.h> +#include <linux/slab.h> + +#include "simple-allocator-priv.h" +#include "../mm/cma.h" + +struct sa_cma_device { + struct sa_device parent; + struct cma *cma; +}; + +struct sa_cma_buffer_info { + void *vaddr; + size_t count; + size_t size; + struct page *pages; + struct sa_cma_device *sa_cma; +}; + +static struct sa_cma_device *sa_cma[MAX_CMA_AREAS]; + +static inline struct sa_cma_device *to_sa_cma(struct sa_device *sadev) +{ + return container_of(sadev, struct sa_cma_device, parent); +} + +static struct sg_table *sa_cma_map_dma_buf(struct dma_buf_attachment *attach, + enum dma_data_direction direction) +{ + struct dma_buf *dmabuf = attach->dmabuf; + struct sa_cma_buffer_info *info = dmabuf->priv; + struct sg_table *sgt; + int ret; + + ret = sg_alloc_table(sgt, 1, GFP_KERNEL); + if (unlikely(ret)) + return NULL; + + sg_set_page(sgt->sgl, info->pages, info->size, 0); + sg_dma_address(sgt->sgl) = (dma_addr_t) page_address(info->pages); + sg_dma_len(sgt->sgl) = info->size; + + return sgt; +} + +static void sa_cma_unmap_dma_buf(struct dma_buf_attachment *attach, + struct sg_table *sgt, + enum dma_data_direction dir) +{ + kfree(sgt); +} + +static int sa_cma_mmap_dma_buf(struct dma_buf *dmabuf, + struct vm_area_struct *vma) +{ + struct sa_cma_buffer_info *info = dmabuf->priv; + unsigned long user_count = vma_pages(vma); + unsigned long count = info->count; + unsigned long pfn = page_to_pfn(info->pages); + unsigned long off = vma->vm_pgoff; + int ret = -ENXIO; + + if (off < count && user_count <= (count - off)) { + ret = remap_pfn_range(vma, vma->vm_start, + pfn + off, + user_count << PAGE_SHIFT, + vma->vm_page_prot); + } + + return ret; +} + +static void sa_cma_release_dma_buf(struct dma_buf *dmabuf) +{ + struct sa_cma_buffer_info *info = dmabuf->priv; + + cma_release(info->sa_cma->cma, info->pages, info->count); + + kfree(info); +} + +static void *sa_cma_kmap_dma_buf(struct dma_buf *dmabuf, unsigned long offset) +{ + struct sa_cma_buffer_info *info = dmabuf->priv; + + return page_address(info->pages) + offset; +} + +static struct dma_buf_ops sa_dma_buf_ops = { + .map_dma_buf = sa_cma_map_dma_buf, + .unmap_dma_buf = sa_cma_unmap_dma_buf, + .mmap = sa_cma_mmap_dma_buf, + .release = sa_cma_release_dma_buf, + .kmap_atomic = sa_cma_kmap_dma_buf, + .kmap = sa_cma_kmap_dma_buf, +}; + +static struct dma_buf *sa_cma_allocate(struct sa_device *sadev, + u64 length, u32 flags) +{ + DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + struct sa_cma_buffer_info *info; + struct dma_buf *dmabuf; + + info = kzalloc(sizeof(*info), GFP_KERNEL); + if (!info) + return NULL; + + info->size = round_up(length, PAGE_SIZE); + info->count = PAGE_ALIGN(info->size) >> PAGE_SHIFT; + info->sa_cma = to_sa_cma(sadev); + + info->pages = cma_alloc(info->sa_cma->cma, info->count, 0); + + if (!info->pages) + goto cleanup; + + exp_info.ops = &sa_dma_buf_ops; + exp_info.size = info->size; + exp_info.flags = flags; + exp_info.priv = info; + + dmabuf = dma_buf_export(&exp_info); + if (IS_ERR(dmabuf)) + goto export_failed; + + return dmabuf; + +export_failed: + cma_release(info->sa_cma->cma, info->pages, info->count); +cleanup: + kfree(info); + return NULL; +} + +struct sa_cma_device *simple_allocator_register_cma(struct cma *cma) +{ + struct sa_cma_device *sa_cma; + int ret; + + sa_cma = kzalloc(sizeof(*sa_cma), GFP_KERNEL); + if (!sa_cma) + return NULL; + + sa_cma->cma = cma; + sa_cma->parent.owner = THIS_MODULE; + sa_cma->parent.name = "cma"; + sa_cma->parent.allocate = sa_cma_allocate; + + ret = simple_allocator_register(&sa_cma->parent); + if (ret) { + kfree(sa_cma); + return NULL; + } + + return sa_cma; +} + +static int __init sa_cma_init(void) +{ + int i; + + for (i = 0; i < cma_area_count; i++) + sa_cma[i] = simple_allocator_register_cma(&cma_areas[i]); + + return 0; +} + +static void __exit sa_cma_exit(void) +{ + int i; + + for (i = 0; i < cma_area_count; i++) + simple_allocator_unregister(&sa_cma[i]->parent); +} + +module_init(sa_cma_init); +module_exit(sa_cma_exit);