/* * 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); mutex_lock(&q->vb_lock); /* 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->vmalloc); vfree(mem->vmalloc); mem->vmalloc = NULL; } q->bufs[i]->map = NULL; q->bufs[i]->baddr = 0; } kfree(map); mutex_unlock(&q->vb_lock); } 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 void *__videobuf_alloc(size_t size) { struct videobuf_vmalloc_memory *mem; struct videobuf_buffer *vb; vb = kzalloc(size+sizeof(*mem),GFP_KERNEL); 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->vmalloc) { 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 1 if (vb->baddr) { printk(KERN_ERR "USERPTR is currently not supported\n"); return -EINVAL; } #endif /* The only USERPTR currently supported is the one needed for read() method. */ mem->vmalloc = vmalloc_user(pages); if (!mem->vmalloc) { printk(KERN_ERR "vmalloc (%d pages) failed\n", pages); return -ENOMEM; } dprintk(1, "vmalloc is at addr %p (%d pages)\n", mem->vmalloc, 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_sync(struct videobuf_queue *q, struct videobuf_buffer *buf) { return 0; } static int __videobuf_mmap_free(struct videobuf_queue *q) { unsigned int i; dprintk(1, "%s\n", __func__); for (i = 0; i < VIDEO_MAX_FRAME; i++) { if (q->bufs[i]) { if (q->bufs[i]->map) return -EBUSY; } } return 0; } static int __videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma) { struct videobuf_vmalloc_memory *mem; struct videobuf_mapping *map; unsigned int first; int retval, pages; unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; dprintk(1, "%s\n", __func__); if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) return -EINVAL; /* look for first buffer to map */ for (first = 0; first < VIDEO_MAX_FRAME; first++) { if (NULL == q->bufs[first]) continue; if (V4L2_MEMORY_MMAP != q->bufs[first]->memory) continue; if (q->bufs[first]->boff == offset) break; } if (VIDEO_MAX_FRAME == first) { dprintk(1,"mmap app bug: offset invalid [offset=0x%lx]\n", (vma->vm_pgoff << PAGE_SHIFT)); return -EINVAL; } /* create mapping + update buffer list */ map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL); if (NULL == map) return -ENOMEM; q->bufs[first]->map = map; map->start = vma->vm_start; map->end = vma->vm_end; map->q = q; q->bufs[first]->baddr = vma->vm_start; mem = q->bufs[first]->priv; BUG_ON(!mem); MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM); pages = PAGE_ALIGN(vma->vm_end - vma->vm_start); mem->vmalloc = vmalloc_user(pages); if (!mem->vmalloc) { printk(KERN_ERR "vmalloc (%d pages) failed\n", pages); goto error; } dprintk(1, "vmalloc is at addr %p (%d pages)\n", mem->vmalloc, pages); /* Try to remap memory */ retval = remap_vmalloc_range(vma, mem->vmalloc, 0); if (retval < 0) { printk(KERN_ERR "mmap: remap failed with error %d. ", retval); vfree(mem->vmalloc); 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) q->bufs[first]->bsize, vma->vm_pgoff, first); videobuf_vm_open(vma); return 0; error: mem = NULL; kfree(map); return -ENOMEM; } static int __videobuf_copy_to_user ( struct videobuf_queue *q, char __user *data, size_t count, int nonblocking ) { struct videobuf_vmalloc_memory *mem=q->read_buf->priv; BUG_ON (!mem); MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM); BUG_ON (!mem->vmalloc); /* copy to userspace */ if (count > q->read_buf->size - q->read_off) count = q->read_buf->size - q->read_off; if (copy_to_user(data, mem->vmalloc+q->read_off, count)) return -EFAULT; return count; } static int __videobuf_copy_stream ( struct videobuf_queue *q, char __user *data, size_t count, size_t pos, int vbihack, int nonblocking ) { unsigned int *fc; struct videobuf_vmalloc_memory *mem=q->read_buf->priv; BUG_ON (!mem); MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM); if (vbihack) { /* dirty, undocumented hack -- pass the frame counter * within the last four bytes of each vbi data block. * We need that one to maintain backward compatibility * to all vbi decoding software out there ... */ fc = (unsigned int*)mem->vmalloc; fc += (q->read_buf->size>>2) -1; *fc = q->read_buf->field_count >> 1; dprintk(1,"vbihack: %d\n",*fc); } /* copy stuff using the common method */ count = __videobuf_copy_to_user (q,data,count,nonblocking); if ( (count==-EFAULT) && (0 == pos) ) return -EFAULT; return count; } static struct videobuf_qtype_ops qops = { .magic = MAGIC_QTYPE_OPS, .alloc = __videobuf_alloc, .iolock = __videobuf_iolock, .sync = __videobuf_sync, .mmap_free = __videobuf_mmap_free, .mmap_mapper = __videobuf_mmap_mapper, .video_copy_to_user = __videobuf_copy_to_user, .copy_stream = __videobuf_copy_stream, .vmalloc = 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) { videobuf_queue_core_init(q, ops, dev, irqlock, type, field, msize, priv, &qops); } 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->vmalloc; } 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->vmalloc); mem->vmalloc = NULL; return; } EXPORT_SYMBOL_GPL(videobuf_vmalloc_free); /* * Local variables: * c-basic-offset: 8 * End: */