essential linux device drivers ch10

來源:互聯網
上載者:User
Accessing PCI Regions

PCI devices contain three addressable regions: configuration space, I/O ports, and device memory

Configuration Space

pci_read_config_[byte|word|dword](struct pci_dev *pdev, int offset, int *value);

and

pci_write_config_[byte|word|dword](struct pci_dev *pdev, int offset, int value);

 

Only the first 64 bytes of the configuration space are standardized. The device manufacturer defines desired semantics to the rest.

 

I/O and Memory

PCI cards have up to six I/O or memory regions. I/O regions contain registers, and memory regions hold data. Video cards, for example, have I/O spaces that accommodate control registers and memory regions that map to frame buffers.

 

unsigned long pci_resource_[start|len|end|flags] (struct pci_dev *pdev, int bar);

1. Get the I/O base address from the appropriate base address register (bar) in the configuration space:

unsigned long io_base = pci_resource_start(pdev, bar);
相關文章

聯繫我們

該頁面正文內容均來源於網絡整理,並不代表阿里雲官方的觀點,該頁面所提到的產品和服務也與阿里云無關,如果該頁面內容對您造成了困擾,歡迎寫郵件給我們,收到郵件我們將在5個工作日內處理。

如果您發現本社區中有涉嫌抄襲的內容,歡迎發送郵件至: info-contact@alibabacloud.com 進行舉報並提供相關證據,工作人員會在 5 個工作天內聯絡您,一經查實,本站將立刻刪除涉嫌侵權內容。

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.