diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-02-27 19:18:30 -0500 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-02-27 19:18:30 -0500 |
commit | 8d37a371b6869920e6c40c495c68eabba1ef3909 (patch) | |
tree | dad784512b13832f4f5494cfe0791965c6a2b0f6 /Documentation | |
parent | ef1a8de8ea004a689b2aa9f5cefcba2b1a0262f2 (diff) | |
parent | 7b4884ca8853a638df0eb5d251d80d67777b8b1a (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6: (49 commits)
pcmcia: validate late-added resources
pcmcia: allow for extension of resource interval
pcmcia: remove useless msleep in ds.c
pcmcia: use read_cis_mem return value
pcmcia: handle error in serial_cs config calls
pcmcia: add locking to pcmcia_{read,write}_cis_mem
pcmcia: avoid prod_id memleak
pcmcia: avoid sysfs-related lockup for cardbus
pcmcia: use state machine for extended requery
pcmcia: delay re-scanning and re-querying of PCMCIA bus
pcmcia: use pccardd to handle eject, insert, suspend and resume requests
pcmcia: use ops_mutex for rsrc_{mgr,nonstatic} locking
pcmcia: use mutex for dynid lock
pcmcia: assert locking to struct pcmcia_device
pcmcia: add locking documentation
pcmcia: simplify locking
pcmcia: add locking to struct pcmcia_socket->pcmcia_state()
pcmcia: protect s->device_count
pcmcia: properly lock skt->irq, skt->irq_mask
pcmcia: lock ops->set_socket
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/pcmcia/locking.txt | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/Documentation/pcmcia/locking.txt b/Documentation/pcmcia/locking.txt new file mode 100644 index 000000000000..68f622bc4064 --- /dev/null +++ b/Documentation/pcmcia/locking.txt | |||
@@ -0,0 +1,118 @@ | |||
1 | This file explains the locking and exclusion scheme used in the PCCARD | ||
2 | and PCMCIA subsystems. | ||
3 | |||
4 | |||
5 | A) Overview, Locking Hierarchy: | ||
6 | =============================== | ||
7 | |||
8 | pcmcia_socket_list_rwsem - protects only the list of sockets | ||
9 | - skt_mutex - serializes card insert / ejection | ||
10 | - ops_mutex - serializes socket operation | ||
11 | |||
12 | |||
13 | B) Exclusion | ||
14 | ============ | ||
15 | |||
16 | The following functions and callbacks to struct pcmcia_socket must | ||
17 | be called with "skt_mutex" held: | ||
18 | |||
19 | socket_detect_change() | ||
20 | send_event() | ||
21 | socket_reset() | ||
22 | socket_shutdown() | ||
23 | socket_setup() | ||
24 | socket_remove() | ||
25 | socket_insert() | ||
26 | socket_early_resume() | ||
27 | socket_late_resume() | ||
28 | socket_resume() | ||
29 | socket_suspend() | ||
30 | |||
31 | struct pcmcia_callback *callback | ||
32 | |||
33 | The following functions and callbacks to struct pcmcia_socket must | ||
34 | be called with "ops_mutex" held: | ||
35 | |||
36 | socket_reset() | ||
37 | socket_setup() | ||
38 | |||
39 | struct pccard_operations *ops | ||
40 | struct pccard_resource_ops *resource_ops; | ||
41 | |||
42 | Note that send_event() and struct pcmcia_callback *callback must not be | ||
43 | called with "ops_mutex" held. | ||
44 | |||
45 | |||
46 | C) Protection | ||
47 | ============= | ||
48 | |||
49 | 1. Global Data: | ||
50 | --------------- | ||
51 | struct list_head pcmcia_socket_list; | ||
52 | |||
53 | protected by pcmcia_socket_list_rwsem; | ||
54 | |||
55 | |||
56 | 2. Per-Socket Data: | ||
57 | ------------------- | ||
58 | The resource_ops and their data are protected by ops_mutex. | ||
59 | |||
60 | The "main" struct pcmcia_socket is protected as follows (read-only fields | ||
61 | or single-use fields not mentioned): | ||
62 | |||
63 | - by pcmcia_socket_list_rwsem: | ||
64 | struct list_head socket_list; | ||
65 | |||
66 | - by thread_lock: | ||
67 | unsigned int thread_events; | ||
68 | |||
69 | - by skt_mutex: | ||
70 | u_int suspended_state; | ||
71 | void (*tune_bridge); | ||
72 | struct pcmcia_callback *callback; | ||
73 | int resume_status; | ||
74 | |||
75 | - by ops_mutex: | ||
76 | socket_state_t socket; | ||
77 | u_int state; | ||
78 | u_short lock_count; | ||
79 | pccard_mem_map cis_mem; | ||
80 | void __iomem *cis_virt; | ||
81 | struct { } irq; | ||
82 | io_window_t io[]; | ||
83 | pccard_mem_map win[]; | ||
84 | struct list_head cis_cache; | ||
85 | size_t fake_cis_len; | ||
86 | u8 *fake_cis; | ||
87 | u_int irq_mask; | ||
88 | void (*zoom_video); | ||
89 | int (*power_hook); | ||
90 | u8 resource...; | ||
91 | struct list_head devices_list; | ||
92 | u8 device_count; | ||
93 | struct pcmcia_state; | ||
94 | |||
95 | |||
96 | 3. Per PCMCIA-device Data: | ||
97 | -------------------------- | ||
98 | |||
99 | The "main" struct pcmcia_devie is protected as follows (read-only fields | ||
100 | or single-use fields not mentioned): | ||
101 | |||
102 | |||
103 | - by pcmcia_socket->ops_mutex: | ||
104 | struct list_head socket_device_list; | ||
105 | struct config_t *function_config; | ||
106 | u16 _irq:1; | ||
107 | u16 _io:1; | ||
108 | u16 _win:4; | ||
109 | u16 _locked:1; | ||
110 | u16 allow_func_id_match:1; | ||
111 | u16 suspended:1; | ||
112 | u16 _removed:1; | ||
113 | |||
114 | - by the PCMCIA driver: | ||
115 | io_req_t io; | ||
116 | irq_req_t irq; | ||
117 | config_req_t conf; | ||
118 | window_handle_t win; | ||