that sounds the wrong approach.. why don't you make your device driver
export an mmap function.. and let the userspace app use that ?
I can't because I need to allocate 128MB of memory per PCI card and if I put for example 4 cards, I'll have 512MB in kernel memory, and I think there will be some problem in kernel.
transfer->Descript[i].size = PAGE_SIZE;
transfer->Descript[i].pciaddr = (ULONG)
virt_to_phys(page_address(iobuf->maplist[idxIobuf]));
you really need to use the PCI DMA mapping api!
I have a plx bridge PCI9656 with a DMA controler. So I have to make a
descriptor table with physical address and size.
I work in 32 bits address mode, but I don't know which function to call
to get a 36bits address for my controler.
Regards.
Sebastien
On Tue, 2005-11-15 at 18:39 +0100, sej wrote:
Hi,
I allocate a big chunck of memory from user space with :
#define MEM_SIZE_DMA (128*1024*1024)
// allocate 128MB of memory
void *_pVirtualMem = memalign(sysconf(_SC_PAGESIZE), MEM_SIZE_DMA);
// Reserve memory
memset(_pVirtualMem, 0, MEM_SIZE_DMA);
// Lock memory
if (!mlock(_pVirtualMem, MEM_SIZE_DMA ))
{
free(_pVirtualMem);
return false;
}
Then I call an IOCTL from my driver (DmaMapDescrpImg) to create a DMA
scatter gather list.
that sounds the wrong approach.. why don't you make your device driver
export an mmap function.. and let the userspace app use that ?
transfer->Descript[i].size = PAGE_SIZE;
transfer->Descript[i].pciaddr = (ULONG)
virt_to_phys(page_address(iobuf->maplist[idxIobuf]));
you really need to use the PCI DMA mapping api!
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