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authorLinus Torvalds <torvalds@linux-foundation.org>2018-02-06 11:27:48 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2018-02-06 11:27:48 -0800
commit68c5735eaa5e680e701c9a2d1e3c7880bdf5ab66 (patch)
tree4f584693638bf257b66a1646cc30d823cacc0a58 /drivers/media/common/videobuf2/videobuf2-memops.c
parent2246edfaf88dc368e8671b04afd54412625df60a (diff)
parent273caa260035c03d89ad63d72d8cd3d9e5c5e3f1 (diff)
Merge tag 'media/v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab: - videobuf2 was moved to a media/common dir, as it is now used by the DVB subsystem too - Digital TV core memory mapped support interface - new sensor driver: ov7740 - several improvements at ddbridge driver - new V4L2 driver: IPU3 CIO2 CSI-2 receiver unit, found on some Intel SoCs - new tuner driver: tda18250 - finally got rid of all LIRC staging drivers - as we don't have old lirc drivers anymore, restruct the lirc device code - add support for UVC metadata - add a new staging driver for NVIDIA Tegra Video Decoder Engine - DVB kAPI headers moved to include/media - synchronize the kAPI and uAPI for the DVB subsystem, removing the gap for non-legacy APIs - reduce the kAPI gap for V4L2 - lots of other driver enhancements, cleanups, etc. * tag 'media/v4.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (407 commits) media: v4l2-compat-ioctl32.c: make ctrl_is_pointer work for subdevs media: v4l2-compat-ioctl32.c: refactor compat ioctl32 logic media: v4l2-compat-ioctl32.c: don't copy back the result for certain errors media: v4l2-compat-ioctl32.c: drop pr_info for unknown buffer type media: v4l2-compat-ioctl32.c: copy clip list in put_v4l2_window32 media: v4l2-compat-ioctl32.c: fix ctrl_is_pointer media: v4l2-compat-ioctl32.c: copy m.userptr in put_v4l2_plane32 media: v4l2-compat-ioctl32.c: avoid sizeof(type) media: v4l2-compat-ioctl32.c: move 'helper' functions to __get/put_v4l2_format32 media: v4l2-compat-ioctl32.c: fix the indentation media: v4l2-compat-ioctl32.c: add missing VIDIOC_PREPARE_BUF media: v4l2-ioctl.c: don't copy back the result for -ENOTTY media: v4l2-ioctl.c: use check_fmt for enum/g/s/try_fmt media: vivid: fix module load error when enabling fb and no_error_inj=1 media: dvb_demux: improve debug messages media: dvb_demux: Better handle discontinuity errors media: cxusb, dib0700: ignore XC2028_I2C_FLUSH media: ts2020: avoid integer overflows on 32 bit machines media: i2c: ov7740: use gpio/consumer.h instead of gpio.h media: entity: Add a nop variant of media_entity_cleanup ...
Diffstat (limited to 'drivers/media/common/videobuf2/videobuf2-memops.c')
-rw-r--r--drivers/media/common/videobuf2/videobuf2-memops.c135
1 files changed, 135 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 000000000000..89e51989332b
--- /dev/null
+++ b/drivers/media/common/videobuf2/videobuf2-memops.c
@@ -0,0 +1,135 @@
+/*
+ * 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;
+ unsigned int flags = FOLL_FORCE;
+
+ if (write)
+ flags |= FOLL_WRITE;
+
+ 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, flags, 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 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");