From 4419b8aca8dc1339a8f01c5e9efbed500780131e Mon Sep 17 00:00:00 2001 From: Andrzej Pietrasiewicz Date: Thu, 13 Oct 2011 07:30:51 -0300 Subject: [PATCH] [media] media: vb2: vmalloc-based allocator user pointer handling This patch adds support for user pointer memory buffers to vmalloc videobuf2 allocator. Signed-off-by: Andrzej Pietrasiewicz Signed-off-by: Kyungmin Park Signed-off-by: Marek Szyprowski CC: Pawel Osciak Signed-off-by: Mauro Carvalho Chehab --- drivers/media/video/videobuf2-vmalloc.c | 90 ++++++++++++++++++++++++++++----- 1 file changed, 78 insertions(+), 12 deletions(-) diff --git a/drivers/media/video/videobuf2-vmalloc.c b/drivers/media/video/videobuf2-vmalloc.c index a3a884234059..4e789a178f8a 100644 --- a/drivers/media/video/videobuf2-vmalloc.c +++ b/drivers/media/video/videobuf2-vmalloc.c @@ -12,6 +12,7 @@ #include #include +#include #include #include @@ -20,7 +21,10 @@ struct vb2_vmalloc_buf { void *vaddr; + struct page **pages; + int write; unsigned long size; + unsigned int n_pages; atomic_t refcount; struct vb2_vmarea_handler handler; }; @@ -31,7 +35,7 @@ static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size) { struct vb2_vmalloc_buf *buf; - buf = kzalloc(sizeof *buf, GFP_KERNEL); + buf = kzalloc(sizeof(*buf), GFP_KERNEL); if (!buf) return NULL; @@ -42,15 +46,12 @@ static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size) buf->handler.arg = buf; if (!buf->vaddr) { - printk(KERN_ERR "vmalloc of size %ld failed\n", buf->size); + pr_debug("vmalloc of size %ld failed\n", buf->size); kfree(buf); return NULL; } atomic_inc(&buf->refcount); - printk(KERN_DEBUG "Allocated vmalloc buffer of size %ld at vaddr=%p\n", - buf->size, buf->vaddr); - return buf; } @@ -59,21 +60,84 @@ static void vb2_vmalloc_put(void *buf_priv) struct vb2_vmalloc_buf *buf = buf_priv; if (atomic_dec_and_test(&buf->refcount)) { - printk(KERN_DEBUG "%s: Freeing vmalloc mem at vaddr=%p\n", - __func__, buf->vaddr); vfree(buf->vaddr); kfree(buf); } } -static void *vb2_vmalloc_vaddr(void *buf_priv) +static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr, + unsigned long size, int write) +{ + struct vb2_vmalloc_buf *buf; + unsigned long first, last; + int n_pages, offset; + + buf = kzalloc(sizeof(*buf), GFP_KERNEL); + if (!buf) + return NULL; + + buf->write = write; + offset = vaddr & ~PAGE_MASK; + buf->size = size; + + 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, write, 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 (vaddr) + vm_unmap_ram((void *)vaddr, buf->n_pages); + for (i = 0; i < buf->n_pages; ++i) { + if (buf->write) + set_page_dirty_lock(buf->pages[i]); + put_page(buf->pages[i]); + } + kfree(buf->pages); + kfree(buf); +} - BUG_ON(!buf); +static void *vb2_vmalloc_vaddr(void *buf_priv) +{ + struct vb2_vmalloc_buf *buf = buf_priv; if (!buf->vaddr) { - printk(KERN_ERR "Address of an unallocated plane requested\n"); + pr_err("Address of an unallocated plane requested " + "or cannot map user pointer\n"); return NULL; } @@ -92,13 +156,13 @@ static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma) int ret; if (!buf) { - printk(KERN_ERR "No memory to map\n"); + pr_err("No memory to map\n"); return -EINVAL; } ret = remap_vmalloc_range(vma, buf->vaddr, 0); if (ret) { - printk(KERN_ERR "Remapping vmalloc memory, error: %d\n", ret); + pr_err("Remapping vmalloc memory, error: %d\n", ret); return ret; } @@ -121,6 +185,8 @@ static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma) 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, .vaddr = vb2_vmalloc_vaddr, .mmap = vb2_vmalloc_mmap, .num_users = vb2_vmalloc_num_users, -- 2.11.0