T-Seriesのトピックalloc DMA memory in SDK 2.0

alloc DMA memory in SDK 2.0

manoloruiz — Fri, 10 Jun 2016 12:01:27 GMT

I am creating a driver for a FPGA connecting by PCI. I want to alloc a dma memory using dma_alloc_coherent and pci_alloc_consistent. However I got the next error:

 pci 0002:01:00.0:  dma_direct_alloc_coherent: No suitable zone for pfn 0x7f000

I am using kernel 4.1 (SDK 2.0). In the previous version worked properly. Any idea how to solve it?

Re: alloc DMA memory in SDK 2.0

manoloruiz — Mon, 13 Jun 2016 06:53:11 GMT

When I boot up the system, I can see the following logs:

Found FSL PCI host bridge at 0x0000000ffe270000. Firmware bus number: 0->1

PCI host bridge /pcie@ffe270000 ranges:

MEM 0x0000000c80000000..0x0000000cffffffff -> 0x0000000080000000

IO 0x0000000ff8030000..0x0000000ff803ffff -> 0x0000000000000000

/pcie@ffe270000: PCICSRBAR @ 0x7f000007

setup_pci_atmu: end of DRAM 100000000

/pcie@ffe270000: Setup 64-bit PCI DMA window

/pcie@ffe270000: DMA window size is 0x7f000007

Is anything to do with the error I have got in my driver?

Re: alloc DMA memory in SDK 2.0

manoloruiz — Thu, 16 Jun 2016 06:52:25 GMT

Any idea how to solve this problem?

Re: alloc DMA memory in SDK 2.0

jimmyzhu — Thu, 15 Jun 2017 07:35:30 GMT

Hi manolo ruiz，

Have you solved this problem?

I have the same problem when I use the kernel linux-4.1.15_2.0.0ga .When use this kernel, I just able to request 256KB dma memery by dma API pci_alloc_consistent.

Could you shared your solution if you have solved this isuue?

Re: alloc DMA memory in SDK 2.0

Pavel — Tue, 20 Jun 2017 01:20:32 GMT

Look at the following pages about DMA for PCI bus using:

http://lwn.net/2001/0712/a/dma-interface.php3

Have a great day,
Pavel Chubakov

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------