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author | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2019-06-12 20:52:53 +0300 |
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committer | Jonathan Corbet <corbet@lwn.net> | 2019-06-14 23:23:35 +0300 |
commit | 3bdab16c55f57a24245c97d707241dd9b48d1a91 (patch) | |
tree | cca861d5430a6c3092bc1a2f1869d9ed13e454e7 /Documentation/pcmcia/locking.rst | |
parent | 593733ab80ac2c607acc1fc3fbaba5031d38253a (diff) | |
download | linux-3bdab16c55f57a24245c97d707241dd9b48d1a91.tar.xz |
docs: pcmcia: convert docs to ReST and rename to *.rst
Convert the pcmcia docs to ReST format. Most of the changes here
are trivial.
The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/pcmcia/locking.rst')
-rw-r--r-- | Documentation/pcmcia/locking.rst | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/Documentation/pcmcia/locking.rst b/Documentation/pcmcia/locking.rst new file mode 100644 index 000000000000..e35257139c89 --- /dev/null +++ b/Documentation/pcmcia/locking.rst @@ -0,0 +1,133 @@ +======= +Locking +======= + +This file explains the locking and exclusion scheme used in the PCCARD +and PCMCIA subsystems. + + +A) Overview, Locking Hierarchy: +=============================== + +pcmcia_socket_list_rwsem + - protects only the list of sockets + +- skt_mutex + - serializes card insert / ejection + + - ops_mutex + - serializes socket operation + + +B) Exclusion +============ + +The following functions and callbacks to struct pcmcia_socket must +be called with "skt_mutex" held:: + + socket_detect_change() + send_event() + socket_reset() + socket_shutdown() + socket_setup() + socket_remove() + socket_insert() + socket_early_resume() + socket_late_resume() + socket_resume() + socket_suspend() + + struct pcmcia_callback *callback + +The following functions and callbacks to struct pcmcia_socket must +be called with "ops_mutex" held:: + + socket_reset() + socket_setup() + + struct pccard_operations *ops + struct pccard_resource_ops *resource_ops; + +Note that send_event() and `struct pcmcia_callback *callback` must not be +called with "ops_mutex" held. + + +C) Protection +============= + +1. Global Data: +--------------- +struct list_head pcmcia_socket_list; + +protected by pcmcia_socket_list_rwsem; + + +2. Per-Socket Data: +------------------- +The resource_ops and their data are protected by ops_mutex. + +The "main" struct pcmcia_socket is protected as follows (read-only fields +or single-use fields not mentioned): + +- by pcmcia_socket_list_rwsem:: + + struct list_head socket_list; + +- by thread_lock:: + + unsigned int thread_events; + +- by skt_mutex:: + + u_int suspended_state; + void (*tune_bridge); + struct pcmcia_callback *callback; + int resume_status; + +- by ops_mutex:: + + socket_state_t socket; + u_int state; + u_short lock_count; + pccard_mem_map cis_mem; + void __iomem *cis_virt; + struct { } irq; + io_window_t io[]; + pccard_mem_map win[]; + struct list_head cis_cache; + size_t fake_cis_len; + u8 *fake_cis; + u_int irq_mask; + void (*zoom_video); + int (*power_hook); + u8 resource...; + struct list_head devices_list; + u8 device_count; + struct pcmcia_state; + + +3. Per PCMCIA-device Data: +-------------------------- + +The "main" struct pcmcia_device is protected as follows (read-only fields +or single-use fields not mentioned): + + +- by pcmcia_socket->ops_mutex:: + + struct list_head socket_device_list; + struct config_t *function_config; + u16 _irq:1; + u16 _io:1; + u16 _win:4; + u16 _locked:1; + u16 allow_func_id_match:1; + u16 suspended:1; + u16 _removed:1; + +- by the PCMCIA driver:: + + io_req_t io; + irq_req_t irq; + config_req_t conf; + window_handle_t win; |