+++ /dev/null
-/*
- * helper functions for vmalloc video4linux capture buffers
- *
- * The functions expect the hardware being able to scatter gather
- * (i.e. the buffers are not linear in physical memory, but fragmented
- * into PAGE_SIZE chunks). They also assume the driver does not need
- * to touch the video data.
- *
- * (c) 2007 Mauro Carvalho Chehab, <mchehab@infradead.org>
- *
- * 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; either version 2
- */
-
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/slab.h>
-#include <linux/interrupt.h>
-
-#include <linux/pci.h>
-#include <linux/vmalloc.h>
-#include <linux/pagemap.h>
-#include <asm/page.h>
-#include <asm/pgtable.h>
-
-#include <media/videobuf-vmalloc.h>
-
-#define MAGIC_DMABUF 0x17760309
-#define MAGIC_VMAL_MEM 0x18221223
-
-#define MAGIC_CHECK(is, should) \
- if (unlikely((is) != (should))) { \
- printk(KERN_ERR "magic mismatch: %x (expected %x)\n", \
- is, should); \
- BUG(); \
- }
-
-static int debug;
-module_param(debug, int, 0644);
-
-MODULE_DESCRIPTION("helper module to manage video4linux vmalloc buffers");
-MODULE_AUTHOR("Mauro Carvalho Chehab <mchehab@infradead.org>");
-MODULE_LICENSE("GPL");
-
-#define dprintk(level, fmt, arg...) \
- if (debug >= level) \
- printk(KERN_DEBUG "vbuf-vmalloc: " fmt , ## arg)
-
-
-/***************************************************************************/
-
-static void videobuf_vm_open(struct vm_area_struct *vma)
-{
- struct videobuf_mapping *map = vma->vm_private_data;
-
- dprintk(2, "vm_open %p [count=%u,vma=%08lx-%08lx]\n", map,
- map->count, vma->vm_start, vma->vm_end);
-
- map->count++;
-}
-
-static void videobuf_vm_close(struct vm_area_struct *vma)
-{
- struct videobuf_mapping *map = vma->vm_private_data;
- struct videobuf_queue *q = map->q;
- int i;
-
- dprintk(2, "vm_close %p [count=%u,vma=%08lx-%08lx]\n", map,
- map->count, vma->vm_start, vma->vm_end);
-
- map->count--;
- if (0 == map->count) {
- struct videobuf_vmalloc_memory *mem;
-
- dprintk(1, "munmap %p q=%p\n", map, q);
- videobuf_queue_lock(q);
-
- /* We need first to cancel streams, before unmapping */
- if (q->streaming)
- videobuf_queue_cancel(q);
-
- for (i = 0; i < VIDEO_MAX_FRAME; i++) {
- if (NULL == q->bufs[i])
- continue;
-
- if (q->bufs[i]->map != map)
- continue;
-
- mem = q->bufs[i]->priv;
- if (mem) {
- /* This callback is called only if kernel has
- allocated memory and this memory is mmapped.
- In this case, memory should be freed,
- in order to do memory unmap.
- */
-
- MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
-
- /* vfree is not atomic - can't be
- called with IRQ's disabled
- */
- dprintk(1, "%s: buf[%d] freeing (%p)\n",
- __func__, i, mem->vaddr);
-
- vfree(mem->vaddr);
- mem->vaddr = NULL;
- }
-
- q->bufs[i]->map = NULL;
- q->bufs[i]->baddr = 0;
- }
-
- kfree(map);
-
- videobuf_queue_unlock(q);
- }
-
- return;
-}
-
-static const struct vm_operations_struct videobuf_vm_ops = {
- .open = videobuf_vm_open,
- .close = videobuf_vm_close,
-};
-
-/* ---------------------------------------------------------------------
- * vmalloc handlers for the generic methods
- */
-
-/* Allocated area consists on 3 parts:
- struct video_buffer
- struct <driver>_buffer (cx88_buffer, saa7134_buf, ...)
- struct videobuf_dma_sg_memory
- */
-
-static struct videobuf_buffer *__videobuf_alloc_vb(size_t size)
-{
- struct videobuf_vmalloc_memory *mem;
- struct videobuf_buffer *vb;
-
- vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
- if (!vb)
- return vb;
-
- mem = vb->priv = ((char *)vb) + size;
- mem->magic = MAGIC_VMAL_MEM;
-
- dprintk(1, "%s: allocated at %p(%ld+%ld) & %p(%ld)\n",
- __func__, vb, (long)sizeof(*vb), (long)size - sizeof(*vb),
- mem, (long)sizeof(*mem));
-
- return vb;
-}
-
-static int __videobuf_iolock(struct videobuf_queue *q,
- struct videobuf_buffer *vb,
- struct v4l2_framebuffer *fbuf)
-{
- struct videobuf_vmalloc_memory *mem = vb->priv;
- int pages;
-
- BUG_ON(!mem);
-
- MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
-
- switch (vb->memory) {
- case V4L2_MEMORY_MMAP:
- dprintk(1, "%s memory method MMAP\n", __func__);
-
- /* All handling should be done by __videobuf_mmap_mapper() */
- if (!mem->vaddr) {
- printk(KERN_ERR "memory is not alloced/mmapped.\n");
- return -EINVAL;
- }
- break;
- case V4L2_MEMORY_USERPTR:
- pages = PAGE_ALIGN(vb->size);
-
- dprintk(1, "%s memory method USERPTR\n", __func__);
-
- if (vb->baddr) {
- printk(KERN_ERR "USERPTR is currently not supported\n");
- return -EINVAL;
- }
-
- /* The only USERPTR currently supported is the one needed for
- * read() method.
- */
-
- mem->vaddr = vmalloc_user(pages);
- if (!mem->vaddr) {
- printk(KERN_ERR "vmalloc (%d pages) failed\n", pages);
- return -ENOMEM;
- }
- dprintk(1, "vmalloc is at addr %p (%d pages)\n",
- mem->vaddr, pages);
-
-#if 0
- int rc;
- /* Kernel userptr is used also by read() method. In this case,
- there's no need to remap, since data will be copied to user
- */
- if (!vb->baddr)
- return 0;
-
- /* FIXME: to properly support USERPTR, remap should occur.
- The code below won't work, since mem->vma = NULL
- */
- /* Try to remap memory */
- rc = remap_vmalloc_range(mem->vma, (void *)vb->baddr, 0);
- if (rc < 0) {
- printk(KERN_ERR "mmap: remap failed with error %d", rc);
- return -ENOMEM;
- }
-#endif
-
- break;
- case V4L2_MEMORY_OVERLAY:
- default:
- dprintk(1, "%s memory method OVERLAY/unknown\n", __func__);
-
- /* Currently, doesn't support V4L2_MEMORY_OVERLAY */
- printk(KERN_ERR "Memory method currently unsupported.\n");
- return -EINVAL;
- }
-
- return 0;
-}
-
-static int __videobuf_mmap_mapper(struct videobuf_queue *q,
- struct videobuf_buffer *buf,
- struct vm_area_struct *vma)
-{
- struct videobuf_vmalloc_memory *mem;
- struct videobuf_mapping *map;
- int retval, pages;
-
- dprintk(1, "%s\n", __func__);
-
- /* create mapping + update buffer list */
- map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
- if (NULL == map)
- return -ENOMEM;
-
- buf->map = map;
- map->q = q;
-
- buf->baddr = vma->vm_start;
-
- mem = buf->priv;
- BUG_ON(!mem);
- MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
-
- pages = PAGE_ALIGN(vma->vm_end - vma->vm_start);
- mem->vaddr = vmalloc_user(pages);
- if (!mem->vaddr) {
- printk(KERN_ERR "vmalloc (%d pages) failed\n", pages);
- goto error;
- }
- dprintk(1, "vmalloc is at addr %p (%d pages)\n", mem->vaddr, pages);
-
- /* Try to remap memory */
- retval = remap_vmalloc_range(vma, mem->vaddr, 0);
- if (retval < 0) {
- printk(KERN_ERR "mmap: remap failed with error %d. ", retval);
- vfree(mem->vaddr);
- goto error;
- }
-
- vma->vm_ops = &videobuf_vm_ops;
- vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
- vma->vm_private_data = map;
-
- dprintk(1, "mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",
- map, q, vma->vm_start, vma->vm_end,
- (long int)buf->bsize,
- vma->vm_pgoff, buf->i);
-
- videobuf_vm_open(vma);
-
- return 0;
-
-error:
- mem = NULL;
- kfree(map);
- return -ENOMEM;
-}
-
-static struct videobuf_qtype_ops qops = {
- .magic = MAGIC_QTYPE_OPS,
-
- .alloc_vb = __videobuf_alloc_vb,
- .iolock = __videobuf_iolock,
- .mmap_mapper = __videobuf_mmap_mapper,
- .vaddr = videobuf_to_vmalloc,
-};
-
-void videobuf_queue_vmalloc_init(struct videobuf_queue *q,
- const struct videobuf_queue_ops *ops,
- struct device *dev,
- spinlock_t *irqlock,
- enum v4l2_buf_type type,
- enum v4l2_field field,
- unsigned int msize,
- void *priv,
- struct mutex *ext_lock)
-{
- videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize,
- priv, &qops, ext_lock);
-}
-EXPORT_SYMBOL_GPL(videobuf_queue_vmalloc_init);
-
-void *videobuf_to_vmalloc(struct videobuf_buffer *buf)
-{
- struct videobuf_vmalloc_memory *mem = buf->priv;
- BUG_ON(!mem);
- MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
-
- return mem->vaddr;
-}
-EXPORT_SYMBOL_GPL(videobuf_to_vmalloc);
-
-void videobuf_vmalloc_free(struct videobuf_buffer *buf)
-{
- struct videobuf_vmalloc_memory *mem = buf->priv;
-
- /* mmapped memory can't be freed here, otherwise mmapped region
- would be released, while still needed. In this case, the memory
- release should happen inside videobuf_vm_close().
- So, it should free memory only if the memory were allocated for
- read() operation.
- */
- if ((buf->memory != V4L2_MEMORY_USERPTR) || buf->baddr)
- return;
-
- if (!mem)
- return;
-
- MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
-
- vfree(mem->vaddr);
- mem->vaddr = NULL;
-
- return;
-}
-EXPORT_SYMBOL_GPL(videobuf_vmalloc_free);
-
git.samba.org / sfrench / cifs-2.6.git / blobdiff