videobuf-vmalloc.rar_Capture

/* * 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_DONTDUMP; 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