diff options
Diffstat (limited to 'kernel/drivers/media/v4l2-core/videobuf2-vmalloc.c')
| -rw-r--r-- | kernel/drivers/media/v4l2-core/videobuf2-vmalloc.c | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/kernel/drivers/media/v4l2-core/videobuf2-vmalloc.c b/kernel/drivers/media/v4l2-core/videobuf2-vmalloc.c new file mode 100644 index 000000000..657ab302a --- /dev/null +++ b/kernel/drivers/media/v4l2-core/videobuf2-vmalloc.c @@ -0,0 +1,464 @@ +/* + * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2 + * + * Copyright (C) 2010 Samsung Electronics + * + * Author: Pawel Osciak <pawel@osciak.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation. + */ + +#include <linux/io.h> +#include <linux/module.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> + +#include <media/videobuf2-core.h> +#include <media/videobuf2-vmalloc.h> +#include <media/videobuf2-memops.h> + +struct vb2_vmalloc_buf { + void *vaddr; + struct page **pages; + struct vm_area_struct *vma; + enum dma_data_direction dma_dir; + unsigned long size; + unsigned int n_pages; + atomic_t refcount; + struct vb2_vmarea_handler handler; + struct dma_buf *dbuf; +}; + +static void vb2_vmalloc_put(void *buf_priv); + +static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size, + enum dma_data_direction dma_dir, gfp_t gfp_flags) +{ + struct vb2_vmalloc_buf *buf; + + buf = kzalloc(sizeof(*buf), GFP_KERNEL | gfp_flags); + if (!buf) + return NULL; + + buf->size = size; + buf->vaddr = vmalloc_user(buf->size); + buf->dma_dir = dma_dir; + buf->handler.refcount = &buf->refcount; + buf->handler.put = vb2_vmalloc_put; + buf->handler.arg = buf; + + if (!buf->vaddr) { + pr_debug("vmalloc of size %ld failed\n", buf->size); + kfree(buf); + return NULL; + } + + atomic_inc(&buf->refcount); + return buf; +} + +static void vb2_vmalloc_put(void *buf_priv) +{ + struct vb2_vmalloc_buf *buf = buf_priv; + + if (atomic_dec_and_test(&buf->refcount)) { + vfree(buf->vaddr); + kfree(buf); + } +} + +static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr, + unsigned long size, + enum dma_data_direction dma_dir) +{ + struct vb2_vmalloc_buf *buf; + unsigned long first, last; + int n_pages, offset; + struct vm_area_struct *vma; + dma_addr_t physp; + + buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + return NULL; + + buf->dma_dir = dma_dir; + offset = vaddr & ~PAGE_MASK; + buf->size = size; + + + vma = find_vma(current->mm, vaddr); + if (vma && (vma->vm_flags & VM_PFNMAP) && (vma->vm_pgoff)) { + if (vb2_get_contig_userptr(vaddr, size, &vma, &physp)) + goto fail_pages_array_alloc; + buf->vma = vma; + buf->vaddr = (__force void *)ioremap_nocache(physp, size); + if (!buf->vaddr) + goto fail_pages_array_alloc; + } else { + first = vaddr >> PAGE_SHIFT; + last = (vaddr + size - 1) >> PAGE_SHIFT; + buf->n_pages = last - first + 1; + buf->pages = kzalloc(buf->n_pages * sizeof(struct page *), + GFP_KERNEL); + if (!buf->pages) + goto fail_pages_array_alloc; + + /* current->mm->mmap_sem is taken by videobuf2 core */ + n_pages = get_user_pages(current, current->mm, + vaddr & PAGE_MASK, buf->n_pages, + dma_dir == DMA_FROM_DEVICE, + 1, /* force */ + buf->pages, NULL); + if (n_pages != buf->n_pages) + goto fail_get_user_pages; + + buf->vaddr = vm_map_ram(buf->pages, buf->n_pages, -1, + PAGE_KERNEL); + if (!buf->vaddr) + goto fail_get_user_pages; + } + + buf->vaddr += offset; + return buf; + +fail_get_user_pages: + pr_debug("get_user_pages requested/got: %d/%d]\n", n_pages, + buf->n_pages); + while (--n_pages >= 0) + put_page(buf->pages[n_pages]); + kfree(buf->pages); + +fail_pages_array_alloc: + kfree(buf); + + return NULL; +} + +static void vb2_vmalloc_put_userptr(void *buf_priv) +{ + struct vb2_vmalloc_buf *buf = buf_priv; + unsigned long vaddr = (unsigned long)buf->vaddr & PAGE_MASK; + unsigned int i; + + if (buf->pages) { + if (vaddr) + vm_unmap_ram((void *)vaddr, buf->n_pages); + for (i = 0; i < buf->n_pages; ++i) { + if (buf->dma_dir == DMA_FROM_DEVICE) + set_page_dirty_lock(buf->pages[i]); + put_page(buf->pages[i]); + } + kfree(buf->pages); + } else { + vb2_put_vma(buf->vma); + iounmap((__force void __iomem *)buf->vaddr); + } + kfree(buf); +} + +static void *vb2_vmalloc_vaddr(void *buf_priv) +{ + struct vb2_vmalloc_buf *buf = buf_priv; + + if (!buf->vaddr) { + pr_err("Address of an unallocated plane requested " + "or cannot map user pointer\n"); + return NULL; + } + + return buf->vaddr; +} + +static unsigned int vb2_vmalloc_num_users(void *buf_priv) +{ + struct vb2_vmalloc_buf *buf = buf_priv; + return atomic_read(&buf->refcount); +} + +static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma) +{ + struct vb2_vmalloc_buf *buf = buf_priv; + int ret; + + if (!buf) { + pr_err("No memory to map\n"); + return -EINVAL; + } + + ret = remap_vmalloc_range(vma, buf->vaddr, 0); + if (ret) { + pr_err("Remapping vmalloc memory, error: %d\n", ret); + return ret; + } + + /* + * Make sure that vm_areas for 2 buffers won't be merged together + */ + vma->vm_flags |= VM_DONTEXPAND; + + /* + * Use common vm_area operations to track buffer refcount. + */ + vma->vm_private_data = &buf->handler; + vma->vm_ops = &vb2_common_vm_ops; + + vma->vm_ops->open(vma); + + return 0; +} + +#ifdef CONFIG_HAS_DMA +/*********************************************/ +/* DMABUF ops for exporters */ +/*********************************************/ + +struct vb2_vmalloc_attachment { + struct sg_table sgt; + enum dma_data_direction dma_dir; +}; + +static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev, + struct dma_buf_attachment *dbuf_attach) +{ + struct vb2_vmalloc_attachment *attach; + struct vb2_vmalloc_buf *buf = dbuf->priv; + int num_pages = PAGE_ALIGN(buf->size) / PAGE_SIZE; + struct sg_table *sgt; + struct scatterlist *sg; + void *vaddr = buf->vaddr; + int ret; + int i; + + attach = kzalloc(sizeof(*attach), GFP_KERNEL); + if (!attach) + return -ENOMEM; + + sgt = &attach->sgt; + ret = sg_alloc_table(sgt, num_pages, GFP_KERNEL); + if (ret) { + kfree(attach); + return ret; + } + for_each_sg(sgt->sgl, sg, sgt->nents, i) { + struct page *page = vmalloc_to_page(vaddr); + + if (!page) { + sg_free_table(sgt); + kfree(attach); + return -ENOMEM; + } + sg_set_page(sg, page, PAGE_SIZE, 0); + vaddr += PAGE_SIZE; + } + + attach->dma_dir = DMA_NONE; + dbuf_attach->priv = attach; + return 0; +} + +static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf, + struct dma_buf_attachment *db_attach) +{ + struct vb2_vmalloc_attachment *attach = db_attach->priv; + struct sg_table *sgt; + + if (!attach) + return; + + sgt = &attach->sgt; + + /* release the scatterlist cache */ + if (attach->dma_dir != DMA_NONE) + dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, + attach->dma_dir); + sg_free_table(sgt); + kfree(attach); + db_attach->priv = NULL; +} + +static struct sg_table *vb2_vmalloc_dmabuf_ops_map( + struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir) +{ + struct vb2_vmalloc_attachment *attach = db_attach->priv; + /* stealing dmabuf mutex to serialize map/unmap operations */ + struct mutex *lock = &db_attach->dmabuf->lock; + struct sg_table *sgt; + int ret; + + mutex_lock(lock); + + sgt = &attach->sgt; + /* return previously mapped sg table */ + if (attach->dma_dir == dma_dir) { + mutex_unlock(lock); + return sgt; + } + + /* release any previous cache */ + if (attach->dma_dir != DMA_NONE) { + dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, + attach->dma_dir); + attach->dma_dir = DMA_NONE; + } + + /* mapping to the client with new direction */ + ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, dma_dir); + if (ret <= 0) { + pr_err("failed to map scatterlist\n"); + mutex_unlock(lock); + return ERR_PTR(-EIO); + } + + attach->dma_dir = dma_dir; + + mutex_unlock(lock); + + return sgt; +} + +static void vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach, + struct sg_table *sgt, enum dma_data_direction dma_dir) +{ + /* nothing to be done here */ +} + +static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf) +{ + /* drop reference obtained in vb2_vmalloc_get_dmabuf */ + vb2_vmalloc_put(dbuf->priv); +} + +static void *vb2_vmalloc_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum) +{ + struct vb2_vmalloc_buf *buf = dbuf->priv; + + return buf->vaddr + pgnum * PAGE_SIZE; +} + +static void *vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf) +{ + struct vb2_vmalloc_buf *buf = dbuf->priv; + + return buf->vaddr; +} + +static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf, + struct vm_area_struct *vma) +{ + return vb2_vmalloc_mmap(dbuf->priv, vma); +} + +static struct dma_buf_ops vb2_vmalloc_dmabuf_ops = { + .attach = vb2_vmalloc_dmabuf_ops_attach, + .detach = vb2_vmalloc_dmabuf_ops_detach, + .map_dma_buf = vb2_vmalloc_dmabuf_ops_map, + .unmap_dma_buf = vb2_vmalloc_dmabuf_ops_unmap, + .kmap = vb2_vmalloc_dmabuf_ops_kmap, + .kmap_atomic = vb2_vmalloc_dmabuf_ops_kmap, + .vmap = vb2_vmalloc_dmabuf_ops_vmap, + .mmap = vb2_vmalloc_dmabuf_ops_mmap, + .release = vb2_vmalloc_dmabuf_ops_release, +}; + +static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flags) +{ + struct vb2_vmalloc_buf *buf = buf_priv; + struct dma_buf *dbuf; + DEFINE_DMA_BUF_EXPORT_INFO(exp_info); + + exp_info.ops = &vb2_vmalloc_dmabuf_ops; + exp_info.size = buf->size; + exp_info.flags = flags; + exp_info.priv = buf; + + if (WARN_ON(!buf->vaddr)) + return NULL; + + dbuf = dma_buf_export(&exp_info); + if (IS_ERR(dbuf)) + return NULL; + + /* dmabuf keeps reference to vb2 buffer */ + atomic_inc(&buf->refcount); + + return dbuf; +} +#endif /* CONFIG_HAS_DMA */ + + +/*********************************************/ +/* callbacks for DMABUF buffers */ +/*********************************************/ + +static int vb2_vmalloc_map_dmabuf(void *mem_priv) +{ + struct vb2_vmalloc_buf *buf = mem_priv; + + buf->vaddr = dma_buf_vmap(buf->dbuf); + + return buf->vaddr ? 0 : -EFAULT; +} + +static void vb2_vmalloc_unmap_dmabuf(void *mem_priv) +{ + struct vb2_vmalloc_buf *buf = mem_priv; + + dma_buf_vunmap(buf->dbuf, buf->vaddr); + buf->vaddr = NULL; +} + +static void vb2_vmalloc_detach_dmabuf(void *mem_priv) +{ + struct vb2_vmalloc_buf *buf = mem_priv; + + if (buf->vaddr) + dma_buf_vunmap(buf->dbuf, buf->vaddr); + + kfree(buf); +} + +static void *vb2_vmalloc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf, + unsigned long size, enum dma_data_direction dma_dir) +{ + struct vb2_vmalloc_buf *buf; + + if (dbuf->size < size) + return ERR_PTR(-EFAULT); + + buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + buf->dbuf = dbuf; + buf->dma_dir = dma_dir; + buf->size = size; + + return buf; +} + + +const struct vb2_mem_ops vb2_vmalloc_memops = { + .alloc = vb2_vmalloc_alloc, + .put = vb2_vmalloc_put, + .get_userptr = vb2_vmalloc_get_userptr, + .put_userptr = vb2_vmalloc_put_userptr, +#ifdef CONFIG_HAS_DMA + .get_dmabuf = vb2_vmalloc_get_dmabuf, +#endif + .map_dmabuf = vb2_vmalloc_map_dmabuf, + .unmap_dmabuf = vb2_vmalloc_unmap_dmabuf, + .attach_dmabuf = vb2_vmalloc_attach_dmabuf, + .detach_dmabuf = vb2_vmalloc_detach_dmabuf, + .vaddr = vb2_vmalloc_vaddr, + .mmap = vb2_vmalloc_mmap, + .num_users = vb2_vmalloc_num_users, +}; +EXPORT_SYMBOL_GPL(vb2_vmalloc_memops); + +MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2"); +MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); +MODULE_LICENSE("GPL"); |