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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/media/common/videobuf2/videobuf2-memops.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/media/common/videobuf2/videobuf2-memops.c')
-rw-r--r-- | drivers/media/common/videobuf2/videobuf2-memops.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/drivers/media/common/videobuf2/videobuf2-memops.c b/drivers/media/common/videobuf2/videobuf2-memops.c new file mode 100644 index 000000000..9dd6c2716 --- /dev/null +++ b/drivers/media/common/videobuf2/videobuf2-memops.c @@ -0,0 +1,129 @@ +/* + * videobuf2-memops.c - generic memory handling routines for videobuf2 + * + * Copyright (C) 2010 Samsung Electronics + * + * Author: Pawel Osciak <pawel@osciak.com> + * Marek Szyprowski <m.szyprowski@samsung.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/slab.h> +#include <linux/module.h> +#include <linux/dma-mapping.h> +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <linux/sched.h> +#include <linux/file.h> + +#include <media/videobuf2-v4l2.h> +#include <media/videobuf2-memops.h> + +/** + * vb2_create_framevec() - map virtual addresses to pfns + * @start: Virtual user address where we start mapping + * @length: Length of a range to map + * + * This function allocates and fills in a vector with pfns corresponding to + * virtual address range passed in arguments. If pfns have corresponding pages, + * page references are also grabbed to pin pages in memory. The function + * returns pointer to the vector on success and error pointer in case of + * failure. Returned vector needs to be freed via vb2_destroy_pfnvec(). + */ +struct frame_vector *vb2_create_framevec(unsigned long start, + unsigned long length) +{ + int ret; + unsigned long first, last; + unsigned long nr; + struct frame_vector *vec; + + first = start >> PAGE_SHIFT; + last = (start + length - 1) >> PAGE_SHIFT; + nr = last - first + 1; + vec = frame_vector_create(nr); + if (!vec) + return ERR_PTR(-ENOMEM); + ret = get_vaddr_frames(start & PAGE_MASK, nr, vec); + if (ret < 0) + goto out_destroy; + /* We accept only complete set of PFNs */ + if (ret != nr) { + ret = -EFAULT; + goto out_release; + } + return vec; +out_release: + put_vaddr_frames(vec); +out_destroy: + frame_vector_destroy(vec); + return ERR_PTR(ret); +} +EXPORT_SYMBOL(vb2_create_framevec); + +/** + * vb2_destroy_framevec() - release vector of mapped pfns + * @vec: vector of pfns / pages to release + * + * This releases references to all pages in the vector @vec (if corresponding + * pfns are backed by pages) and frees the passed vector. + */ +void vb2_destroy_framevec(struct frame_vector *vec) +{ + put_vaddr_frames(vec); + frame_vector_destroy(vec); +} +EXPORT_SYMBOL(vb2_destroy_framevec); + +/** + * vb2_common_vm_open() - increase refcount of the vma + * @vma: virtual memory region for the mapping + * + * This function adds another user to the provided vma. It expects + * struct vb2_vmarea_handler pointer in vma->vm_private_data. + */ +static void vb2_common_vm_open(struct vm_area_struct *vma) +{ + struct vb2_vmarea_handler *h = vma->vm_private_data; + + pr_debug("%s: %p, refcount: %d, vma: %08lx-%08lx\n", + __func__, h, refcount_read(h->refcount), vma->vm_start, + vma->vm_end); + + refcount_inc(h->refcount); +} + +/** + * vb2_common_vm_close() - decrease refcount of the vma + * @vma: virtual memory region for the mapping + * + * This function releases the user from the provided vma. It expects + * struct vb2_vmarea_handler pointer in vma->vm_private_data. + */ +static void vb2_common_vm_close(struct vm_area_struct *vma) +{ + struct vb2_vmarea_handler *h = vma->vm_private_data; + + pr_debug("%s: %p, refcount: %d, vma: %08lx-%08lx\n", + __func__, h, refcount_read(h->refcount), vma->vm_start, + vma->vm_end); + + h->put(h->arg); +} + +/* + * vb2_common_vm_ops - common vm_ops used for tracking refcount of mmapped + * video buffers + */ +const struct vm_operations_struct vb2_common_vm_ops = { + .open = vb2_common_vm_open, + .close = vb2_common_vm_close, +}; +EXPORT_SYMBOL_GPL(vb2_common_vm_ops); + +MODULE_DESCRIPTION("common memory handling routines for videobuf2"); +MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>"); +MODULE_LICENSE("GPL"); |