^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) =======
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) Locking
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) =======
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) This file explains the locking and exclusion scheme used in the PCCARD
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) and PCMCIA subsystems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) A) Overview, Locking Hierarchy:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) ===============================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) pcmcia_socket_list_rwsem
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) - protects only the list of sockets
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) - skt_mutex
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) - serializes card insert / ejection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) - ops_mutex
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) - serializes socket operation
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) B) Exclusion
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) ============
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) The following functions and callbacks to struct pcmcia_socket must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) be called with "skt_mutex" held::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) socket_detect_change()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) send_event()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) socket_reset()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) socket_shutdown()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) socket_setup()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) socket_remove()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) socket_insert()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) socket_early_resume()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) socket_late_resume()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) socket_resume()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) socket_suspend()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) struct pcmcia_callback *callback
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) The following functions and callbacks to struct pcmcia_socket must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) be called with "ops_mutex" held::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) socket_reset()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) socket_setup()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) struct pccard_operations *ops
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) struct pccard_resource_ops *resource_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) Note that send_event() and `struct pcmcia_callback *callback` must not be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) called with "ops_mutex" held.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) C) Protection
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) =============
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 1. Global Data:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) ---------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) struct list_head pcmcia_socket_list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) protected by pcmcia_socket_list_rwsem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 2. Per-Socket Data:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) -------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) The resource_ops and their data are protected by ops_mutex.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) The "main" struct pcmcia_socket is protected as follows (read-only fields
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) or single-use fields not mentioned):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) - by pcmcia_socket_list_rwsem::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) struct list_head socket_list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) - by thread_lock::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) unsigned int thread_events;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) - by skt_mutex::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) u_int suspended_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) void (*tune_bridge);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) struct pcmcia_callback *callback;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) int resume_status;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) - by ops_mutex::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) socket_state_t socket;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) u_int state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) u_short lock_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) pccard_mem_map cis_mem;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) void __iomem *cis_virt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) struct { } irq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) io_window_t io[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) pccard_mem_map win[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) struct list_head cis_cache;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) size_t fake_cis_len;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) u8 *fake_cis;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) u_int irq_mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) void (*zoom_video);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) int (*power_hook);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) u8 resource...;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) struct list_head devices_list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) u8 device_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) struct pcmcia_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 3. Per PCMCIA-device Data:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) --------------------------
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) The "main" struct pcmcia_device is protected as follows (read-only fields
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) or single-use fields not mentioned):
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) - by pcmcia_socket->ops_mutex::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) struct list_head socket_device_list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) struct config_t *function_config;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) u16 _irq:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) u16 _io:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) u16 _win:4;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) u16 _locked:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) u16 allow_func_id_match:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) u16 suspended:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) u16 _removed:1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) - by the PCMCIA driver::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) io_req_t io;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) irq_req_t irq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) config_req_t conf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) window_handle_t win;
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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