cregit-Linux how code gets into the kernel

Release 4.7 drivers/media/v4l2-core/videobuf2-memops.c

/*
 * 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
 * @write:      Should we map for writing into the area
 *
 * 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, bool write) { 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, write, true, 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); }

Contributors

PersonTokensPropCommitsCommitProp
jan karajan kara14497.96%150.00%
ricardo ribaldaricardo ribalda32.04%150.00%
Total147100.00%2100.00%

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); }

Contributors

PersonTokensPropCommitsCommitProp
jan karajan kara20100.00%1100.00%
Total20100.00%1100.00%

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, atomic_read(h->refcount), vma->vm_start, vma->vm_end); atomic_inc(h->refcount); }

Contributors

PersonTokensPropCommitsCommitProp
marek szyprowskimarek szyprowski5098.04%150.00%
uwe kleine-koeniguwe kleine-koenig11.96%150.00%
Total51100.00%2100.00%

/** * 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, atomic_read(h->refcount), vma->vm_start, vma->vm_end); h->put(h->arg); }

Contributors

PersonTokensPropCommitsCommitProp
marek szyprowskimarek szyprowski5298.11%150.00%
uwe kleine-koeniguwe kleine-koenig11.89%150.00%
Total53100.00%2100.00%

/** * vb2_common_vm_ops - common vm_ops used for tracking refcount of mmaped * 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");

Overall Contributors

PersonTokensPropCommitsCommitProp
jan karajan kara17650.14%116.67%
marek szyprowskimarek szyprowski16747.58%116.67%
ricardo ribaldaricardo ribalda30.85%116.67%
pawel osciakpawel osciak20.57%116.67%
uwe kleine-koeniguwe kleine-koenig20.57%116.67%
junghak sungjunghak sung10.28%116.67%
Total351100.00%6100.00%
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