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staging: comedi: adl_pci9118: use dma_alloc_coherent()

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Use `dma_alloc_coherent()` to allocate the DMA buffers instead of
using `__get_free_pages()` to allocate and `virt_to_bus()` to get the
hardware address.  The coherent buffers are fairly small - at most 4
pages (although there are two of them).  Use of `virt_to_bus()` is
discouraged.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ian Abbott 2014-09-12 10:04:44 +01:00 committed by Greg Kroah-Hartman
parent f39f87e9ea
commit 75fbdbf61d
2 changed files with 11 additions and 11 deletions
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2
drivers/staging/comedi/Kconfig
View file

@ -740,7 +740,7 @@ config COMEDI_ADL_PCI9111
config COMEDI_ADL_PCI9118
tristate "ADLink PCI-9118DG, PCI-9118HG, PCI-9118HR support"
select COMEDI_FC
depends on VIRT_TO_BUS
depends on HAS_DMA
---help---
Enable support for ADlink PCI-9118DG, PCI-9118HG, PCI-9118HR cards

20
drivers/staging/comedi/drivers/adl_pci9118.c
View file

@ -204,11 +204,10 @@ static const struct pci9118_boardinfo pci9118_boards[] = {
};
struct pci9118_dmabuf {
unsigned long virt; /* virtual address of buffer */
unsigned long hw; /* hardware (bus) address of buffer */
unsigned short *virt; /* virtual address of buffer */
dma_addr_t hw; /* hardware (bus) address of buffer */
unsigned int size; /* size of dma buffer in bytes */
unsigned int use_size; /* which size we may now use for transfer */
int order; /* log2 number of pages in buffer */
};
struct pci9118_private {
@ -475,12 +474,11 @@ static unsigned int defragment_dma_buffer(struct comedi_device *dev,
static int move_block_from_dma(struct comedi_device *dev,
struct comedi_subdevice *s,
unsigned long virt_addr,
unsigned short *dma_buffer,
unsigned int num_samples)
{
struct pci9118_private *devpriv = dev->private;
struct comedi_cmd *cmd = &s->async->cmd;
unsigned short *dma_buffer = (unsigned short *)virt_addr;
unsigned int num_bytes;
num_samples = defragment_dma_buffer(dev, s, dma_buffer, num_samples);
@ -1485,15 +1483,15 @@ static void pci9118_alloc_dma(struct comedi_device *dev)
for (i = 0; i < 2; i++) {
dmabuf = &devpriv->dmabuf[i];
for (order = 2; order >= 0; order--) {
dmabuf->virt = __get_free_pages(GFP_KERNEL, order);
dmabuf->virt =
dma_alloc_coherent(dev->hw_dev, PAGE_SIZE << order,
&dmabuf->hw, GFP_KERNEL);
if (dmabuf->virt)
break;
}
if (!dmabuf->virt)
break;
dmabuf->order = order;
dmabuf->size = PAGE_SIZE << order;
dmabuf->hw = virt_to_bus((void *)dmabuf->virt);
if (i == 0)
devpriv->master = 1;
@ -1513,8 +1511,10 @@ static void pci9118_free_dma(struct comedi_device *dev)
for (i = 0; i < 2; i++) {
dmabuf = &devpriv->dmabuf[i];
if (dmabuf->virt)
free_pages(dmabuf->virt, dmabuf->order);
if (dmabuf->virt) {
dma_free_coherent(dev->hw_dev, dmabuf->size,
dmabuf->virt, dmabuf->hw);
}
}
}