diff options
author | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-10-26 14:14:45 -0200 |
---|---|---|
committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2016-12-15 08:54:52 -0200 |
commit | 6634fbb6b6356e6f5b428a349952b368b25d514d (patch) | |
tree | 4802ea45935c1581b6c471750f2b4c242e78baa2 /Documentation/driver-api/edac.rst | |
parent | e01aa14cf2e7ff6d39614f8087800d08ba1629b2 (diff) |
driver-api: create an edac.rst file with EDAC documentation
Currently, there's no device driver documentation for the EDAC
subsystem at the driver-api book. Fill in the blanks for the
structures and functions that misses documentation, uniform
the word on the existing ones, and add a new edac.rst file at
driver-api, in order to document the EDAC subsystem.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Diffstat (limited to 'Documentation/driver-api/edac.rst')
-rw-r--r-- | Documentation/driver-api/edac.rst | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/Documentation/driver-api/edac.rst b/Documentation/driver-api/edac.rst new file mode 100644 index 000000000000..3771e768fda1 --- /dev/null +++ b/Documentation/driver-api/edac.rst @@ -0,0 +1,72 @@ +Error Detection And Correction (EDAC) Devices +============================================= + +Memory Controllers +------------------ + +Most of the EDAC core is focused on doing Memory Controller error detection. +The :c:func:`edac_mc_alloc`. It uses internally the struct ``mem_ctl_info`` +to describe the memory controllers, with is an opaque struct for the EDAC +drivers. Only the EDAC core is allowed to touch it. + +.. kernel-doc:: include/linux/edac.h + +.. kernel-doc:: drivers/edac/edac_mc.h + +PCI Controllers +--------------- + +The EDAC subsystem provides a mechanism to handle PCI controllers by calling +the :c:func:`edac_pci_alloc_ctl_info`. It will use the struct +:c:type:`edac_pci_ctl_info` to describe the PCI controllers. + +.. kernel-doc:: drivers/edac/edac_pci.h + +EDAC Blocks +----------- + +The EDAC subsystem also provides a generic mechanism to report errors on +other parts of the hardware via :c:func:`edac_device_alloc_ctl_info` function. + +The structures :c:type:`edac_dev_sysfs_block_attribute`, +:c:type:`edac_device_block`, :c:type:`edac_device_instance` and +:c:type:`edac_device_ctl_info` provide a generic or abstract 'edac_device' +representation at sysfs. + +This set of structures and the code that implements the APIs for the same, provide for registering EDAC type devices which are NOT standard memory or +PCI, like: + +- CPU caches (L1 and L2) +- DMA engines +- Core CPU switches +- Fabric switch units +- PCIe interface controllers +- other EDAC/ECC type devices that can be monitored for + errors, etc. + +It allows for a 2 level set of hierarchy. + +For example, a cache could be composed of L1, L2 and L3 levels of cache. +Each CPU core would have its own L1 cache, while sharing L2 and maybe L3 +caches. On such case, those can be represented via the following sysfs +nodes:: + + /sys/devices/system/edac/.. + + pci/ <existing pci directory (if available)> + mc/ <existing memory device directory> + cpu/cpu0/.. <L1 and L2 block directory> + /L1-cache/ce_count + /ue_count + /L2-cache/ce_count + /ue_count + cpu/cpu1/.. <L1 and L2 block directory> + /L1-cache/ce_count + /ue_count + /L2-cache/ce_count + /ue_count + ... + + the L1 and L2 directories would be "edac_device_block's" + +.. kernel-doc:: drivers/edac/edac_device.h |