From: Pawel Osciak <p.osciak@xxxxxxxxxxx>
Add an implementation of contiguous virtual memory allocator and handling
routines for videobuf2, implemented on top of vmalloc()/vfree() calls.
Signed-off-by: Pawel Osciak <p.osciak@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
drivers/media/video/Kconfig | 5 +
drivers/media/video/Makefile | 1 +
drivers/media/video/videobuf2-vmalloc.c | 177 +++++++++++++++++++++++++++++++
include/media/videobuf2-vmalloc.h | 16 +++
4 files changed, 199 insertions(+), 0 deletions(-)
create mode 100644 drivers/media/video/videobuf2-vmalloc.c
create mode 100644 include/media/videobuf2-vmalloc.h
diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 2acb0f8..83d49a7 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -55,6 +55,11 @@ config VIDEOBUF2_CORE
config VIDEOBUF2_MEMOPS
tristate
+config VIDEOBUF2_VMALLOC
+ select VIDEOBUF2_CORE
+ select VIDEOBUF2_MEMOPS
+ tristate
+
#
# Multimedia Video device configuration
#
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index 77cc798..18f68fc 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -119,6 +119,7 @@ obj-$(CONFIG_VIDEO_BTCX) += btcx-risc.o
obj-$(CONFIG_VIDEOBUF2_CORE) += videobuf2-core.o
obj-$(CONFIG_VIDEOBUF2_MEMOPS) += videobuf2-memops.o
+obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2-vmalloc.o
obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o
diff --git a/drivers/media/video/videobuf2-vmalloc.c b/drivers/media/video/videobuf2-vmalloc.c
new file mode 100644
index 0000000..3310900
--- /dev/null
+++ b/drivers/media/video/videobuf2-vmalloc.c
@@ -0,0 +1,177 @@
+/*
+ * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <p.osciak@xxxxxxxxxxx>
+ *
+ * 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/module.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-memops.h>
+
+struct vb2_vmalloc_conf {
+ struct vb2_alloc_ctx alloc_ctx;
+};
+
+struct vb2_vmalloc_buf {
+ void *vaddr;
+ unsigned long size;
+ unsigned int refcount;
+};
+
+static void *vb2_vmalloc_alloc(const struct vb2_alloc_ctx *alloc_ctx,
+ unsigned long size)
+{
+ struct vb2_vmalloc_buf *buf;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ buf->size = size;
+ buf->vaddr = vmalloc_user(buf->size);
+ if (!buf->vaddr) {
+ printk(KERN_ERR "vmalloc of size %ld failed\n", buf->size);
+ kfree(buf);
+ return NULL;
+ }
+
+ buf->refcount++;
+ printk(KERN_DEBUG "Allocated vmalloc buffer of size %ld at vaddr=%p\n",
+ buf->size, buf->vaddr);
+
+ return buf;
+}
+
+static void vb2_vmalloc_put(void *buf_priv)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+
+ buf->refcount--;
+
+ if (0 == 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)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+
+ BUG_ON(!buf);
+
+ if (!buf->vaddr) {
+ printk(KERN_ERR "Address of an unallocated "
+ "plane requested\n");
+ return NULL;
+ }
+
+ return buf->vaddr;
+}
+
+static unsigned int vb2_vmalloc_num_users(void *buf_priv)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+
+ return buf->refcount;
+}
+
+/* TODO generalize and extract to core as much as possible */
+static void vb2_vmalloc_vm_open(struct vm_area_struct *vma)
+{
+ struct vb2_vmalloc_buf *buf = vma->vm_private_data;
+
+ printk(KERN_DEBUG "%s vmalloc_priv: %p, refcount: %d, "
+ "vma: %08lx-%08lx\n", __func__, buf, buf->refcount,
+ vma->vm_start, vma->vm_end);
+
+ buf->refcount++;
+}
+
+static void vb2_vmalloc_vm_close(struct vm_area_struct *vma)
+{
+ struct vb2_vmalloc_buf *buf = vma->vm_private_data;
+
+ printk(KERN_DEBUG "%s vmalloc_priv: %p, refcount: %d, "
+ "vma: %08lx-%08lx\n", __func__, buf, buf->refcount,
+ vma->vm_start, vma->vm_end);
+
+ vb2_vmalloc_put(buf);
+}
+
+static const struct vm_operations_struct vb2_vmalloc_vm_ops = {
+ .open = vb2_vmalloc_vm_open,
+ .close = vb2_vmalloc_vm_close,
+};
+
+static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+ int ret;
+
+ if (!buf) {
+ printk(KERN_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);
+ return ret;
+ }
+
+ vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
+ vma->vm_private_data = buf;
+ vma->vm_ops = &vb2_vmalloc_vm_ops;
+
+ vb2_vmalloc_vm_open(vma);
+
+ return 0;
+}
+
+static const struct vb2_mem_ops vb2_vmalloc_ops = {
+ .alloc = vb2_vmalloc_alloc,
+ .put = vb2_vmalloc_put,
+ .vaddr = vb2_vmalloc_vaddr,
+ .mmap = vb2_vmalloc_mmap,
+ .num_users = vb2_vmalloc_num_users,
+};
+
+struct vb2_alloc_ctx *vb2_vmalloc_init(void)
+{
+ struct vb2_vmalloc_conf *conf;
+
+ conf = kzalloc(sizeof *conf, GFP_KERNEL);
+ if (!conf)
+ return ERR_PTR(-ENOMEM);
+
+ conf->alloc_ctx.mem_ops = &vb2_vmalloc_ops;
+
+ return &conf->alloc_ctx;
+}
+EXPORT_SYMBOL_GPL(vb2_vmalloc_init);
+
+void vb2_vmalloc_cleanup(struct vb2_alloc_ctx *alloc_ctx)
+{
+ struct vb2_vmalloc_conf *conf =
+ container_of(alloc_ctx, struct vb2_vmalloc_conf, alloc_ctx);
+
+ kfree(conf);
+}
+EXPORT_SYMBOL_GPL(vb2_vmalloc_cleanup);
+
+MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
+MODULE_AUTHOR("Pawel Osciak");
+MODULE_LICENSE("GPL");
diff --git a/include/media/videobuf2-vmalloc.h b/include/media/videobuf2-vmalloc.h
new file mode 100644
index 0000000..7612f9f
--- /dev/null
+++ b/include/media/videobuf2-vmalloc.h
@@ -0,0 +1,16 @@
+/*
+ * videobuf2-vmalloc.h - vmalloc memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <p.osciak@xxxxxxxxxxx>
+ *
+ * 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 <media/videobuf2-core.h>
+
+struct vb2_alloc_ctx *vb2_vmalloc_init(void);
+void vb2_vmalloc_cleanup(struct vb2_alloc_ctx *alloc_ctx);
--
1.7.1.569.g6f426
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