linux/drivers/media/video/ivtv/ivtv-udma.c

201 lines
5.7 KiB
C

/*
User DMA
Copyright (C) 2003-2004 Kevin Thayer <nufan_wfk at yahoo.com>
Copyright (C) 2004 Chris Kennedy <c@groovy.org>
Copyright (C) 2005-2007 Hans Verkuil <hverkuil@xs4all.nl>
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 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "ivtv-driver.h"
#include "ivtv-streams.h"
#include "ivtv-udma.h"
void ivtv_udma_get_page_info(struct ivtv_dma_page_info *dma_page, unsigned long first, unsigned long size)
{
dma_page->uaddr = first & PAGE_MASK;
dma_page->offset = first & ~PAGE_MASK;
dma_page->tail = 1 + ((first+size-1) & ~PAGE_MASK);
dma_page->first = (first & PAGE_MASK) >> PAGE_SHIFT;
dma_page->last = ((first+size-1) & PAGE_MASK) >> PAGE_SHIFT;
dma_page->page_count = dma_page->last - dma_page->first + 1;
if (dma_page->page_count == 1) dma_page->tail -= dma_page->offset;
}
int ivtv_udma_fill_sg_list (struct ivtv_user_dma *dma, struct ivtv_dma_page_info *dma_page, int map_offset)
{
int i, offset;
offset = dma_page->offset;
/* Fill SG Array with new values */
for (i = 0; i < dma_page->page_count; i++) {
if (i == dma_page->page_count - 1) {
dma->SGlist[map_offset].length = dma_page->tail;
}
else {
dma->SGlist[map_offset].length = PAGE_SIZE - offset;
}
dma->SGlist[map_offset].offset = offset;
dma->SGlist[map_offset].page = dma->map[map_offset];
offset = 0;
map_offset++;
}
return map_offset;
}
void ivtv_udma_fill_sg_array (struct ivtv_user_dma *dma, u32 buffer_offset, u32 buffer_offset_2, u32 split) {
int i;
struct scatterlist *sg;
for (i = 0, sg = dma->SGlist; i < dma->SG_length; i++, sg++) {
dma->SGarray[i].size = cpu_to_le32(sg_dma_len(sg));
dma->SGarray[i].src = cpu_to_le32(sg_dma_address(sg));
dma->SGarray[i].dst = cpu_to_le32(buffer_offset);
buffer_offset += sg_dma_len(sg);
split -= sg_dma_len(sg);
if (split == 0)
buffer_offset = buffer_offset_2;
}
}
/* User DMA Buffers */
void ivtv_udma_alloc(struct ivtv *itv)
{
if (itv->udma.SG_handle == 0) {
/* Map DMA Page Array Buffer */
itv->udma.SG_handle = pci_map_single(itv->dev, itv->udma.SGarray,
sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
ivtv_udma_sync_for_cpu(itv);
}
}
int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr,
void __user *userbuf, int size_in_bytes)
{
struct ivtv_dma_page_info user_dma;
struct ivtv_user_dma *dma = &itv->udma;
int err;
IVTV_DEBUG_DMA("ivtv_udma_setup, dst: 0x%08x\n", (unsigned int)ivtv_dest_addr);
/* Still in USE */
if (dma->SG_length || dma->page_count) {
IVTV_DEBUG_WARN("ivtv_udma_setup: SG_length %d page_count %d still full?\n",
dma->SG_length, dma->page_count);
return -EBUSY;
}
ivtv_udma_get_page_info(&user_dma, (unsigned long)userbuf, size_in_bytes);
if (user_dma.page_count <= 0) {
IVTV_DEBUG_WARN("ivtv_udma_setup: Error %d page_count from %d bytes %d offset\n",
user_dma.page_count, size_in_bytes, user_dma.offset);
return -EINVAL;
}
/* Get user pages for DMA Xfer */
down_read(&current->mm->mmap_sem);
err = get_user_pages(current, current->mm,
user_dma.uaddr, user_dma.page_count, 0, 1, dma->map, NULL);
up_read(&current->mm->mmap_sem);
if (user_dma.page_count != err) {
IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",
err, user_dma.page_count);
return -EINVAL;
}
dma->page_count = user_dma.page_count;
/* Fill SG List with new values */
ivtv_udma_fill_sg_list(dma, &user_dma, 0);
/* Map SG List */
dma->SG_length = pci_map_sg(itv->dev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
/* Fill SG Array with new values */
ivtv_udma_fill_sg_array (dma, ivtv_dest_addr, 0, -1);
/* Tag SG Array with Interrupt Bit */
dma->SGarray[dma->SG_length - 1].size |= cpu_to_le32(0x80000000);
ivtv_udma_sync_for_device(itv);
return dma->page_count;
}
void ivtv_udma_unmap(struct ivtv *itv)
{
struct ivtv_user_dma *dma = &itv->udma;
int i;
IVTV_DEBUG_INFO("ivtv_unmap_user_dma\n");
/* Nothing to free */
if (dma->page_count == 0)
return;
/* Unmap Scatterlist */
if (dma->SG_length) {
pci_unmap_sg(itv->dev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
dma->SG_length = 0;
}
/* sync DMA */
ivtv_udma_sync_for_cpu(itv);
/* Release User Pages */
for (i = 0; i < dma->page_count; i++) {
put_page(dma->map[i]);
}
dma->page_count = 0;
}
void ivtv_udma_free(struct ivtv *itv)
{
/* Unmap SG Array */
if (itv->udma.SG_handle) {
pci_unmap_single(itv->dev, itv->udma.SG_handle,
sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
}
/* Unmap Scatterlist */
if (itv->udma.SG_length) {
pci_unmap_sg(itv->dev, itv->udma.SGlist, itv->udma.page_count, PCI_DMA_TODEVICE);
}
}
void ivtv_udma_start(struct ivtv *itv)
{
IVTV_DEBUG_DMA("start UDMA\n");
write_reg(itv->udma.SG_handle, IVTV_REG_DECDMAADDR);
write_reg_sync(read_reg(IVTV_REG_DMAXFER) | 0x01, IVTV_REG_DMAXFER);
set_bit(IVTV_F_I_DMA, &itv->i_flags);
set_bit(IVTV_F_I_UDMA, &itv->i_flags);
}
void ivtv_udma_prepare(struct ivtv *itv)
{
unsigned long flags;
spin_lock_irqsave(&itv->dma_reg_lock, flags);
if (!test_bit(IVTV_F_I_DMA, &itv->i_flags))
ivtv_udma_start(itv);
else
set_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags);
spin_unlock_irqrestore(&itv->dma_reg_lock, flags);
}