diff options
Diffstat (limited to 'Documentation/filesystems/sysfs-pci.txt')
-rw-r--r-- | Documentation/filesystems/sysfs-pci.txt | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/Documentation/filesystems/sysfs-pci.txt b/Documentation/filesystems/sysfs-pci.txt index 85354b32d731..74eaac26f8b8 100644 --- a/Documentation/filesystems/sysfs-pci.txt +++ b/Documentation/filesystems/sysfs-pci.txt | |||
@@ -39,7 +39,7 @@ files, each with their own function. | |||
39 | local_cpus nearby CPU mask (cpumask, ro) | 39 | local_cpus nearby CPU mask (cpumask, ro) |
40 | remove remove device from kernel's list (ascii, wo) | 40 | remove remove device from kernel's list (ascii, wo) |
41 | resource PCI resource host addresses (ascii, ro) | 41 | resource PCI resource host addresses (ascii, ro) |
42 | resource0..N PCI resource N, if present (binary, mmap) | 42 | resource0..N PCI resource N, if present (binary, mmap, rw[1]) |
43 | resource0_wc..N_wc PCI WC map resource N, if prefetchable (binary, mmap) | 43 | resource0_wc..N_wc PCI WC map resource N, if prefetchable (binary, mmap) |
44 | rom PCI ROM resource, if present (binary, ro) | 44 | rom PCI ROM resource, if present (binary, ro) |
45 | subsystem_device PCI subsystem device (ascii, ro) | 45 | subsystem_device PCI subsystem device (ascii, ro) |
@@ -54,13 +54,16 @@ files, each with their own function. | |||
54 | binary - file contains binary data | 54 | binary - file contains binary data |
55 | cpumask - file contains a cpumask type | 55 | cpumask - file contains a cpumask type |
56 | 56 | ||
57 | [1] rw for RESOURCE_IO (I/O port) regions only | ||
58 | |||
57 | The read only files are informational, writes to them will be ignored, with | 59 | The read only files are informational, writes to them will be ignored, with |
58 | the exception of the 'rom' file. Writable files can be used to perform | 60 | the exception of the 'rom' file. Writable files can be used to perform |
59 | actions on the device (e.g. changing config space, detaching a device). | 61 | actions on the device (e.g. changing config space, detaching a device). |
60 | mmapable files are available via an mmap of the file at offset 0 and can be | 62 | mmapable files are available via an mmap of the file at offset 0 and can be |
61 | used to do actual device programming from userspace. Note that some platforms | 63 | used to do actual device programming from userspace. Note that some platforms |
62 | don't support mmapping of certain resources, so be sure to check the return | 64 | don't support mmapping of certain resources, so be sure to check the return |
63 | value from any attempted mmap. | 65 | value from any attempted mmap. The most notable of these are I/O port |
66 | resources, which also provide read/write access. | ||
64 | 67 | ||
65 | The 'enable' file provides a counter that indicates how many times the device | 68 | The 'enable' file provides a counter that indicates how many times the device |
66 | has been enabled. If the 'enable' file currently returns '4', and a '1' is | 69 | has been enabled. If the 'enable' file currently returns '4', and a '1' is |