![Hans Verkuil](/assets/img/avatar_default.png)
Never use sg++, always use sg = sg_next(sg). Scatterlist entries can be combined if the memory is contiguous but sg++ won't know about that. As far as I can tell cx88 and ivtv are really broken because of this, and bttv and cx25821 are OK because vb1 doesn't combine scatterlist entries. But regardless, sg++ should never be used, only sg_next is safe. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
235 lines
6.6 KiB
C
235 lines
6.6 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-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;
|
|
unsigned long flags;
|
|
|
|
if (map_offset < 0)
|
|
return map_offset;
|
|
|
|
offset = dma_page->offset;
|
|
|
|
/* Fill SG Array with new values */
|
|
for (i = 0; i < dma_page->page_count; i++) {
|
|
unsigned int len = (i == dma_page->page_count - 1) ?
|
|
dma_page->tail : PAGE_SIZE - offset;
|
|
|
|
if (PageHighMem(dma->map[map_offset])) {
|
|
void *src;
|
|
|
|
if (dma->bouncemap[map_offset] == NULL)
|
|
dma->bouncemap[map_offset] = alloc_page(GFP_KERNEL);
|
|
if (dma->bouncemap[map_offset] == NULL)
|
|
return -1;
|
|
local_irq_save(flags);
|
|
src = kmap_atomic(dma->map[map_offset]) + offset;
|
|
memcpy(page_address(dma->bouncemap[map_offset]) + offset, src, len);
|
|
kunmap_atomic(src);
|
|
local_irq_restore(flags);
|
|
sg_set_page(&dma->SGlist[map_offset], dma->bouncemap[map_offset], len, offset);
|
|
}
|
|
else {
|
|
sg_set_page(&dma->SGlist[map_offset], dma->map[map_offset], len, 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 = sg_next(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->pdev, 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 i, 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(¤t->mm->mmap_sem);
|
|
err = get_user_pages(current, current->mm,
|
|
user_dma.uaddr, user_dma.page_count, 0, 1, dma->map, NULL);
|
|
up_read(¤t->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);
|
|
if (err >= 0) {
|
|
for (i = 0; i < err; i++)
|
|
put_page(dma->map[i]);
|
|
return -EINVAL;
|
|
}
|
|
return err;
|
|
}
|
|
|
|
dma->page_count = user_dma.page_count;
|
|
|
|
/* Fill SG List with new values */
|
|
if (ivtv_udma_fill_sg_list(dma, &user_dma, 0) < 0) {
|
|
for (i = 0; i < dma->page_count; i++) {
|
|
put_page(dma->map[i]);
|
|
}
|
|
dma->page_count = 0;
|
|
return -ENOMEM;
|
|
}
|
|
|
|
/* Map SG List */
|
|
dma->SG_length = pci_map_sg(itv->pdev, 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->pdev, 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)
|
|
{
|
|
int i;
|
|
|
|
/* Unmap SG Array */
|
|
if (itv->udma.SG_handle) {
|
|
pci_unmap_single(itv->pdev, itv->udma.SG_handle,
|
|
sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
|
|
}
|
|
|
|
/* Unmap Scatterlist */
|
|
if (itv->udma.SG_length) {
|
|
pci_unmap_sg(itv->pdev, itv->udma.SGlist, itv->udma.page_count, PCI_DMA_TODEVICE);
|
|
}
|
|
|
|
for (i = 0; i < IVTV_DMA_SG_OSD_ENT; i++) {
|
|
if (itv->udma.bouncemap[i])
|
|
__free_page(itv->udma.bouncemap[i]);
|
|
}
|
|
}
|
|
|
|
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);
|
|
clear_bit(IVTV_F_I_UDMA_PENDING, &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);
|
|
}
|