93 строки
1.9 KiB
Plaintext
93 строки
1.9 KiB
Plaintext
|
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
|
||
|
|
|
||
|
|
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 are on their own to provide proper locking.
|
||
|
|
|
||
|
|
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;
|