1 files changed, 417 insertions, 0 deletions

diff --git a/drivers/media/video/videobuf-dma-contig.c b/drivers/media/video/videobuf-dma-contig.c
new file mode 100644
index 000000000000..2475535cbe7f
--- /dev/null
+++ b/drivers/media/video/videobuf-dma-contig.c
@@ -0,0 +1,417 @@
+/*
+ * helper functions for physically contiguous capture buffers
+ *
+ * The functions support hardware lacking scatter gather support
+ * (i.e. the buffers must be linear in physical memory)
+ *
+ * Copyright (c) 2008 Magnus Damm
+ *
+ * Based on videobuf-vmalloc.c,
+ * (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/dma-mapping.h>
+#include <media/videobuf-dma-contig.h>
+
+struct videobuf_dma_contig_memory {
+        u32 magic;
+        void *vaddr;
+        dma_addr_t dma_handle;
+        unsigned long size;
+};
+
+#define MAGIC_DC_MEM 0x0733ac61
+#define MAGIC_CHECK(is, should)                                         \
+        if (unlikely((is) != (should))) {                               \
+                pr_err("magic mismatch: %x expected %x\n", is, should); \
+                BUG();                                                  \
+        }
+
+static void
+videobuf_vm_open(struct vm_area_struct *vma)
+{
+        struct videobuf_mapping *map = vma->vm_private_data;
+
+        dev_dbg(map->q->dev, "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;
+
+        dev_dbg(map->q->dev, "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_dma_contig_memory *mem;
+
+                dev_dbg(map->q->dev, "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_DC_MEM);
+
+                                /* vfree is not atomic - can't be
+                                   called with IRQ's disabled
+                                 */
+                                dev_dbg(map->q->dev, "buf[%d] freeing %p\n",
+                                        i, mem->vaddr);
+
+                                dma_free_coherent(q->dev, mem->size,
+                                                  mem->vaddr, mem->dma_handle);
+                                mem->vaddr = NULL;
+                        }
+
+                        q->bufs[i]->map   = NULL;
+                        q->bufs[i]->baddr = 0;
+                }
+
+                kfree(map);
+
+                mutex_unlock(&q->vb_lock);
+        }
+}
+
+static struct vm_operations_struct videobuf_vm_ops = {
+        .open     = videobuf_vm_open,
+        .close    = videobuf_vm_close,
+};
+
+static void *__videobuf_alloc(size_t size)
+{
+        struct videobuf_dma_contig_memory *mem;
+        struct videobuf_buffer *vb;
+
+        vb = kzalloc(size + sizeof(*mem), GFP_KERNEL);
+        if (vb) {
+                mem = vb->priv = ((char *)vb) + size;
+                mem->magic = MAGIC_DC_MEM;
+        }
+
+        return vb;
+}
+
+static void *__videobuf_to_vmalloc(struct videobuf_buffer *buf)
+{
+        struct videobuf_dma_contig_memory *mem = buf->priv;
+
+        BUG_ON(!mem);
+        MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
+
+        return mem->vaddr;
+}
+
+static int __videobuf_iolock(struct videobuf_queue *q,
+                             struct videobuf_buffer *vb,
+                             struct v4l2_framebuffer *fbuf)
+{
+        struct videobuf_dma_contig_memory *mem = vb->priv;
+
+        BUG_ON(!mem);
+        MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
+
+        switch (vb->memory) {
+        case V4L2_MEMORY_MMAP:
+                dev_dbg(q->dev, "%s memory method MMAP\n", __func__);
+
+                /* All handling should be done by __videobuf_mmap_mapper() */
+                if (!mem->vaddr) {
+                        dev_err(q->dev, "memory is not alloced/mmapped.\n");
+                        return -EINVAL;
+                }
+                break;
+        case V4L2_MEMORY_USERPTR:
+                dev_dbg(q->dev, "%s memory method USERPTR\n", __func__);
+
+                /* The only USERPTR currently supported is the one needed for
+                   read() method.
+                 */
+                if (vb->baddr)
+                        return -EINVAL;
+
+                mem->size = PAGE_ALIGN(vb->size);
+                mem->vaddr = dma_alloc_coherent(q->dev, mem->size,
+                                                &mem->dma_handle, GFP_KERNEL);
+                if (!mem->vaddr) {
+                        dev_err(q->dev, "dma_alloc_coherent %ld failed\n",
+                                         mem->size);
+                        return -ENOMEM;
+                }
+
+                dev_dbg(q->dev, "dma_alloc_coherent data is at %p (%ld)\n",
+                        mem->vaddr, mem->size);
+                break;
+        case V4L2_MEMORY_OVERLAY:
+        default:
+                dev_dbg(q->dev, "%s memory method OVERLAY/unknown\n",
+                        __func__);
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static int __videobuf_sync(struct videobuf_queue *q,
+                           struct videobuf_buffer *buf)
+{
+        struct videobuf_dma_contig_memory *mem = buf->priv;
+
+        BUG_ON(!mem);
+        MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
+
+        dma_sync_single_for_cpu(q->dev, mem->dma_handle, mem->size,
+                                DMA_FROM_DEVICE);
+        return 0;
+}
+
+static int __videobuf_mmap_free(struct videobuf_queue *q)
+{
+        unsigned int i;
+
+        dev_dbg(q->dev, "%s\n", __func__);
+        for (i = 0; i < VIDEO_MAX_FRAME; i++) {
+                if (q->bufs[i] && q->bufs[i]->map)
+                        return -EBUSY;
+        }
+
+        return 0;
+}
+
+static int __videobuf_mmap_mapper(struct videobuf_queue *q,
+                                  struct vm_area_struct *vma)
+{
+        struct videobuf_dma_contig_memory *mem;
+        struct videobuf_mapping *map;
+        unsigned int first;
+        int retval;
+        unsigned long size, offset = vma->vm_pgoff << PAGE_SHIFT;
+
+        dev_dbg(q->dev, "%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 (!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) {
+                dev_dbg(q->dev, "invalid user space offset [offset=0x%lx]\n",
+                        offset);
+                return -EINVAL;
+        }
+
+        /* create mapping + update buffer list */
+        map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
+        if (!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_DC_MEM);
+
+        mem->size = PAGE_ALIGN(q->bufs[first]->bsize);
+        mem->vaddr = dma_alloc_coherent(q->dev, mem->size,
+                                        &mem->dma_handle, GFP_KERNEL);
+        if (!mem->vaddr) {
+                dev_err(q->dev, "dma_alloc_coherent size %ld failed\n",
+                        mem->size);
+                goto error;
+        }
+        dev_dbg(q->dev, "dma_alloc_coherent data is at addr %p (size %ld)\n",
+                mem->vaddr, mem->size);
+
+        /* Try to remap memory */
+
+        size = vma->vm_end - vma->vm_start;
+        size = (size < mem->size) ? size : mem->size;
+
+        vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+        retval = remap_pfn_range(vma, vma->vm_start,
+                                 mem->dma_handle >> PAGE_SHIFT,
+                                 size, vma->vm_page_prot);
+        if (retval) {
+                dev_err(q->dev, "mmap: remap failed with error %d. ", retval);
+                dma_free_coherent(q->dev, mem->size,
+                                  mem->vaddr, mem->dma_handle);
+                goto error;
+        }
+
+        vma->vm_ops          = &videobuf_vm_ops;
+        vma->vm_flags       |= VM_DONTEXPAND;
+        vma->vm_private_data = map;
+
+        dev_dbg(q->dev, "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:
+        kfree(map);
+        return -ENOMEM;
+}
+
+static int __videobuf_copy_to_user(struct videobuf_queue *q,
+                                   char __user *data, size_t count,
+                                   int nonblocking)
+{
+        struct videobuf_dma_contig_memory *mem = q->read_buf->priv;
+        void *vaddr;
+
+        BUG_ON(!mem);
+        MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
+        BUG_ON(!mem->vaddr);
+
+        /* copy to userspace */
+        if (count > q->read_buf->size - q->read_off)
+                count = q->read_buf->size - q->read_off;
+
+        vaddr = mem->vaddr;
+
+        if (copy_to_user(data, vaddr + 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_dma_contig_memory *mem = q->read_buf->priv;
+
+        BUG_ON(!mem);
+        MAGIC_CHECK(mem->magic, MAGIC_DC_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->vaddr;
+                fc += (q->read_buf->size >> 2) - 1;
+                *fc = q->read_buf->field_count >> 1;
+                dev_dbg(q->dev, "vbihack: %d\n", *fc);
+        }
+
+        /* copy stuff using the common method */
+        count = __videobuf_copy_to_user(q, data, count, nonblocking);
+
+        if ((count == -EFAULT) && (pos == 0))
+                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_dma_contig_init(struct videobuf_queue *q,
+                                    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_dma_contig_init);
+
+dma_addr_t videobuf_to_dma_contig(struct videobuf_buffer *buf)
+{
+        struct videobuf_dma_contig_memory *mem = buf->priv;
+
+        BUG_ON(!mem);
+        MAGIC_CHECK(mem->magic, MAGIC_DC_MEM);
+
+        return mem->dma_handle;
+}
+EXPORT_SYMBOL_GPL(videobuf_to_dma_contig);
+
+void videobuf_dma_contig_free(struct videobuf_queue *q,
+                              struct videobuf_buffer *buf)
+{
+        struct videobuf_dma_contig_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_DC_MEM);
+
+        dma_free_coherent(q->dev, mem->size, mem->vaddr, mem->dma_handle);
+        mem->vaddr = NULL;
+}
+EXPORT_SYMBOL_GPL(videobuf_dma_contig_free);
+
+MODULE_DESCRIPTION("helper module to manage video4linux dma contig buffers");
+MODULE_AUTHOR("Magnus Damm");
+MODULE_LICENSE("GPL");