; Initialization of the USB subsystem.
; Provides usb_init procedure, includes all needed files.
; General notes:
; * There is one entry point for external kernel code: usb_init is called
; from initialization code and initializes USB subsystem.
; * There are several entry points for API; see the docs for description.
; * There are several functions which are called from controller-specific
; parts of USB subsystem. The most important is usb_new_device,
; which is called when a new device has been connected (over some time),
; has been reset and is ready to start configuring.
; * IRQ handlers are very restricted. They can not take any locks,
; since otherwise a deadlock is possible: imagine that a code has taken the
; lock and was interrupted by IRQ handler. Now IRQ handler would wait for
; releasing the lock, and a lock owner would wait for exiting IRQ handler
; to get the control.
; * Thus, there is the special USB thread which processes almost all activity.
; IRQ handlers do the minimal processing and wake this thread.
; * Also the USB thread wakes occasionally to process tasks which can be
; predicted without interrupts. These include e.g. a periodic roothub
; scanning in UHCI and initializing in USB_CONNECT_DELAY ticks
; after connecting a new device.
; * The main procedure of USB thread, usb_thread_proc, does all its work
; by querying usb_hardware_func.ProcessDeferred for every controller
; and usb_hub_process_deferred for every hub.
; ProcessDeferred does controller-specific actions and calculates the time
; when it should be invoked again, possibly infinite.
; usb_thread_proc selects the minimum from all times returned by
; ProcessDeferred and sleeps until this moment is reached or the thread
; is awakened by IRQ handler.
; Initializes the USB subsystem.
proc usb_init
; 1. Initialize all locks.
mov ecx, usb_controllers_list_mutex
call mutex_init
mov ecx, usb1_ep_mutex
call mutex_init
mov ecx, usb_gtd_mutex
call mutex_init
mov ecx, ehci_ep_mutex
call mutex_init
mov ecx, ehci_gtd_mutex
call mutex_init
; 2. Kick off BIOS from all USB controllers, calling the corresponding function
; *hci_kickoff_bios. Also count USB controllers for the next step.
; Note: USB1 companion(s) must go before the corresponding EHCI controller,
; otherwise BIOS could see a device moving from EHCI to a companion;
; first, this always wastes time;
; second, some BIOSes are buggy, do not expect that move and try to refer to
; previously-assigned controller instead of actual; sometimes that leads to
; hangoff.
; Thus, process controllers in PCI order.
mov esi, pcidev_list
push 0
.kickoff:
mov esi, [esi+PCIDEV.fd]
cmp esi, pcidev_list
jz .done_kickoff
cmp word [esi+PCIDEV.class+1], 0x0C03
jnz .kickoff
mov eax, uhci_kickoff_bios
cmp byte [esi+PCIDEV.class], 0x00
jz .do_kickoff
mov eax, ohci_kickoff_bios
cmp byte [esi+PCIDEV.class], 0x10
jz .do_kickoff
mov eax, ehci_kickoff_bios
cmp byte [esi+PCIDEV.class], 0x20
jnz .kickoff
.do_kickoff:
inc dword [esp]
call eax
jmp .kickoff
.done_kickoff:
pop eax
; 3. If no controllers were found, exit.
; Otherwise, run the USB thread.
test eax, eax
jz .nothing
call create_usb_thread
jz .nothing
; 4. Initialize all USB controllers, calling usb_init_controller for each.
; Note: USB1 companion(s) should go before the corresponding EHCI controller,
; although this is not strictly necessary (this way, a companion would not try
; to initialize high-speed device only to see a disconnect when EHCI takes
; control).
; Thus, process all EHCI controllers in the first loop, all USB1 controllers
; in the second loop. (One loop in reversed PCI order could also be used,
; but seems less natural.)
; 4a. Loop over all PCI devices, call usb_init_controller
; for all EHCI controllers.
mov eax, pcidev_list
.scan_ehci:
mov eax, [eax+PCIDEV.fd]
cmp eax, pcidev_list
jz .done_ehci
cmp [eax+PCIDEV.class], 0x0C0320
jnz .scan_ehci
mov edi, ehci_hardware_func
call usb_init_controller
jmp .scan_ehci
.done_ehci:
; 4b. Loop over all PCI devices, call usb_init_controller
; for all UHCI and OHCI controllers.
mov eax, pcidev_list
.scan_usb1:
mov eax, [eax+PCIDEV.fd]
cmp eax, pcidev_list
jz .done_usb1
mov edi, uhci_hardware_func
cmp [eax+PCIDEV.class], 0x0C0300
jz @f
mov edi, ohci_hardware_func
cmp [eax+PCIDEV.class], 0x0C0310
jnz .scan_usb1
@@:
call usb_init_controller
jmp .scan_usb1
.done_usb1:
.nothing:
ret
endp
uglobal
align 4
usb_event dd ?
endg
; Helper function for usb_init. Creates and initializes the USB thread.
proc create_usb_thread
; 1. Create the thread.
push edi
push 1
pop ebx
mov ecx, usb_thread_proc
xor edx, edx
call new_sys_threads
pop edi
; If failed, say something to the debug board and return with ZF set.
test eax, eax
jns @f
DEBUGF 1,'K : cannot create kernel thread for USB, error %d\n',eax
.clear:
xor eax, eax
jmp .nothing
@@:
; 2. Wait while the USB thread initializes itself.
@@:
call change_task
cmp [usb_event], 0
jz @b
; 3. If initialization failed, the USB thread sets [usb_event] to -1.
; Return with ZF set or cleared corresponding to the result.
cmp [usb_event], -1
jz .clear
.nothing:
ret
endp
; Helper function for IRQ handlers. Wakes the USB thread if ebx is nonzero.
proc usb_wakeup_if_needed
test ebx, ebx
jz usb_wakeup.nothing
usb_wakeup:
xor edx, edx
mov eax, [usb_event]
mov ebx, [eax+EVENT.id]
xor esi, esi
call raise_event
.nothing:
ret
endp
; Main loop of the USB thread.
proc usb_thread_proc
; 1. Initialize: create event to allow wakeup by interrupt handlers.
xor esi, esi
mov ecx, MANUAL_DESTROY
call create_event
test eax, eax
jnz @f
; If failed, set [usb_event] to -1 and terminate myself.
dbgstr 'cannot create event for USB thread'
or [usb_event], -1
jmp sys_end
@@:
mov [usb_event], eax
push -1 ; initial timeout: infinite
usb_thread_wait:
; 2. Main loop: wait for either wakeup event or timeout.
pop ecx ; get timeout
mov eax, [usb_event]
mov ebx, [eax+EVENT.id]
call wait_event_timeout
push -1 ; default timeout: infinite
; 3. Main loop: call worker functions of all controllers;
; if some function schedules wakeup in timeout less than the current value,
; replace that value with the returned timeout.
mov esi, usb_controllers_list
@@:
mov esi, [esi+usb_controller.Next]
cmp esi, usb_controllers_list
jz .controllers_done
mov eax, [esi+usb_controller.HardwareFunc]
call [eax+usb_hardware_func.ProcessDeferred]
cmp [esp], eax
jb @b
mov [esp], eax
jmp @b
.controllers_done:
; 4. Main loop: call hub worker function for all hubs,
; similarly calculating minimum of all returned timeouts.
; When done, continue to 2.
mov esi, usb_hubs_list
@@:
mov esi, [esi+usb_hub.Next]
cmp esi, usb_hubs_list
jz usb_thread_wait
call usb_hub_process_deferred
cmp [esp], eax
jb @b
mov [esp], eax
jmp @b
endp
iglobal
align 4
usb_controllers_list:
dd usb_controllers_list
dd usb_controllers_list
usb_hubs_list:
dd usb_hubs_list
dd usb_hubs_list
endg
uglobal
align 4
usb_controllers_list_mutex MUTEX
endg
include "memory.inc"
include "hccommon.inc"
include "pipe.inc"
include "ohci.inc"
include "uhci.inc"
include "ehci.inc"
include "protocol.inc"
include "hub.inc"
include "scheduler.inc"