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; Code for UHCI controllers.

; Note: it should be moved to an external driver,

; it was convenient to have this code compiled into the kernel during initial

; development, but there are no reasons to keep it here.

; =============================================================================

; ================================= Constants =================================

; =============================================================================

; UHCI register declarations

UhciCommandReg     = 0

UhciStatusReg      = 2

UhciInterruptReg   = 4

UhciFrameNumberReg = 6

UhciBaseAddressReg = 8

UhciSOFModifyReg   = 0Ch

UhciPort1StatusReg = 10h

; possible PIDs for USB data transfers

USB_PID_SETUP = 2Dh

USB_PID_IN    = 69h

USB_PID_OUT   = 0E1h

; UHCI does not support an interrupt on root hub status change. We must poll

; the controller periodically. This is the period in timer ticks (10ms).

; We use the value 100 ms: it is valid value for USB hub poll rate (1-255 ms),

; small enough to be responsible to connect events and large enough to not

; load CPU too often.

UHCI_POLL_INTERVAL = 100

; the following constant is an invalid encoding for length fields in

; uhci_gtd; it is used to check whether an inactive TD has been

; completed (actual length of the transfer is valid) or not processed at all

; (actual length of the transfer is UHCI_INVALID_LENGTH).

; Valid values are 0-4FFh and 7FFh. We use 700h as an invalid value.

UHCI_INVALID_LENGTH = 700h

; =============================================================================

; ================================ Structures =================================

; =============================================================================

; UHCI-specific part of a pipe descriptor.

; * The structure corresponds to the Queue Head aka QH from the UHCI

;   specification with some additional fields.

; * The hardware uses first two fields (8 bytes). Next two fields are used for

;   software book-keeping.

; * The hardware requires 16-bytes alignment of the hardware part.

;   Since the allocator (usb_allocate_common) allocates memory sequentially

;   from page start (aligned on 0x1000 bytes), size of the structure must be

;   divisible by 16.

struct uhci_pipe

NextQH          dd      ?

; 1. First bit (bit 0) is Terminate bit. 1 = there is no next QH.

; 2. Next bit (bit 1) is QH/TD select bit. 1 = NextQH points to QH.

; 3. Next two bits (bits 2-3) are reserved.

; 4. With masked 4 lower bits, this is the physical address of the next QH in

;    the QH list.

; See also the description before NextVirt field of the usb_pipe

; structure. Additionally to that description, the following is specific for

; the UHCI controller:

; * n=10, N=1024. However, this number is quite large.

; * 1024 lists are used only for individual transfer descriptors for

;   Isochronous endpoints. This means that the software can sleep up to 1024 ms

;   before initiating the next portion of a large isochronous transfer, which

;   is a sufficiently large value.

; * We use the 32ms upper limit for interrupt endpoint polling interval.

;   This seems to be a reasonable value.

; * The "next" list for last Periodic list is the Control list.

; * The "next" list for Control list is Bulk list and the "next"

;   list for Bulk list is Control list. This loop is used for bandwidth

;   reclamation: the hardware traverses lists until end-of-frame.

HeadTD          dd      ?

; 1. First bit (bit 0) is Terminate bit. 1 = there is no TDs in this QH.

; 2. Next bit (bit 1) is QH/TD select bit. 1 = HeadTD points to QH.

; 3. Next two bits (bits 2-3) are reserved.

; 4. With masked 4 lower bits, this is the physical address of the first TD in

;    the TD queue for this QH.

Token           dd      ?

; This field is a template for uhci_gtd.Token field in transfer

; descriptors. The meaning of individual bits is the same as for

; uhci_gtd.Token, except that PID bitfield is always

; USB_PID_SETUP/IN/OUT for control/in/out pipes,

; the MaximumLength bitfield encodes maximum packet size,

; the Reserved bit 20 is LowSpeedDevice bit.

ErrorTD         dd      ?

; Usually NULL. If nonzero, it is a pointer to descriptor which was error'd

; and should be freed sometime in the future (the hardware could still use it).

SoftwarePart    rd      sizeof.usb_pipe/4

; Common part for all controllers, described by usb_pipe structure.

ends

if sizeof.uhci_pipe mod 16

.err uhci_pipe must be 16-bytes aligned

end if

; This structure describes the static head of every list of pipes.

; The hardware requires 16-bytes alignment of this structure.

; All instances of this structure are located sequentially in uhci_controller,

; uhci_controller is page-aligned, so it is sufficient to make this structure

; 16-bytes aligned and verify that the first instance is 16-bytes aligned

; inside uhci_controller.

struct uhci_static_ep

NextQH          dd      ?

; Same as uhci_pipe.NextQH.

HeadTD          dd      ?

; Same as uhci_pipe.HeadTD.

NextList        dd      ?

; Virtual address of the next list.

                dd      ?

; Not used.

SoftwarePart    rd      sizeof.usb_static_ep/4

; Common part for all controllers, described by usb_static_ep structure.

                dd      ?

; Padding for 16-byte alignment.

ends

if sizeof.uhci_static_ep mod 16

.err uhci_static_ep must be 16-bytes aligned

end if

; UHCI-specific part of controller data.

; * The structure includes two parts, the hardware part and the software part.

; * The hardware part consists of first 4096 bytes and corresponds to

;   the Frame List from UHCI specification.

; * The hardware requires page-alignment of the hardware part, so

;   the entire descriptor must be page-aligned.

;   This structure is allocated with kernel_alloc (see usb_init_controller),

;   this gives page-aligned data.

struct uhci_controller

; ------------------------------ hardware fields ------------------------------

FrameList       rd      1024

; Entry n corresponds to the head of the frame list to be executed in

; the frames n,n+1024,n+2048,n+3072,...

; The first bit of each entry is Terminate bit, 1 = the frame is empty.

; The second bit of each entry is QH/TD select bit, 1 = the entry points to

; QH, 0 = to TD.

; With masked 2 lower bits, the entry is a physical address of the first QH/TD

; to be executed.

; ------------------------------ software fields ------------------------------

; Every list has the static head, which is an always empty QH.

; The following fields are static heads, one per list:

; 32+16+8+4+2+1 = 63 for Periodic lists, 1 for Control list and 1 for Bulk list.

IntEDs          uhci_static_ep

                rb      62 * sizeof.uhci_static_ep

ControlED       uhci_static_ep

BulkED          uhci_static_ep

IOBase          dd      ?

; Base port in I/O space for UHCI controller.

; UHCI register UhciXxx is addressed as in/out to IOBase + UhciXxx,

; see declarations in the beginning of this source.

DeferredActions dd      ?

; Bitmask of bits from UhciStatusReg which need to be processed

; by uhci_process_deferred. Bit 0 = a transaction with IOC bit

; has completed. Bit 1 = a transaction has failed. Set by uhci_irq,

; cleared by uhci_process_deferred.

LastPollTime    dd      ?

; See the comment before UHCI_POLL_INTERVAL. This variable keeps the

; last time, in timer ticks, when the polling was done.

ends

if uhci_controller.IntEDs mod 16

.err Static endpoint descriptors must be 16-bytes aligned inside uhci_controller

end if

; UHCI general transfer descriptor.

; * The structure describes non-Isochronous data transfers

;   for the UHCI controller.

; * The structure includes two parts, the hardware part and the software part.

; * The hardware part consists of first 16 bytes and corresponds to the

;   Transfer Descriptor aka TD from UHCI specification.

; * The hardware requires 16-bytes alignment of the hardware part, so

;   the entire descriptor must be 16-bytes aligned. Since the allocator

;   (uhci_allocate_common) allocates memory sequentially from page start

;   (aligned on 0x1000 bytes), size of the structure must be divisible by 16.

struct uhci_gtd

NextTD          dd      ?

; 1. First bit (bit 0) is Terminate bit. 1 = there is no next TD.

; 2. Next bit (bit 1) is QH/TD select bit. 1 = NextTD points to QH.

;    This bit is always set to 0 in the implementation.

; 3. Next bit (bit 2) is Depth/Breadth select bit. 1 = the controller should

;    proceed to the NextTD after this TD is complete. 0 = the controller

;    should proceed to the next endpoint after this TD is complete.

;    The implementation sets this bit to 0 for final stages of all transactions

;    and to 1 for other stages.

; 4. Next bit (bit 3) is reserved and must be zero.

; 5. With masked 4 lower bits, this is the physical address of the next TD

;    in the TD list.

ControlStatus   dd      ?

; 1. Lower 11 bits (bits 0-10) are ActLen. This is written by the controller

;    at the conclusion of a USB transaction to indicate the actual number of

;    bytes that were transferred minus 1.

; 2. Next 6 bits (bits 11-16) are reserved.

; 3. Next bit (bit 17) signals Bitstuff error.

; 4. Next bit (bit 18) signals CRC/Timeout error.

; 5. Next bit (bit 19) signals NAK receive.

; 6. Next bit (bit 20) signals Babble error.

; 7. Next bit (bit 21) signals Data Buffer error.

; 8. Next bit (bit 22) signals Stall error.

; 9. Next bit (bit 23) is Active field. 1 = this TD should be processed.

; 10. Next bit (bit 24) is InterruptOnComplete bit. 1 = the controller should

;     issue an interrupt on completion of the frame in which this TD is

;     executed.

; 11. Next bit (bit 25) is IsochronousSelect bit. 1 = this TD is isochronous.

; 12. Next bit (bit 26) is LowSpeedDevice bit. 1 = this TD is for low-speed.

; 13. Next two bits (bits 27-28) are ErrorCounter field. This field is

;     decremented by the controller on every non-fatal error with this TD.

;     Babble and Stall are considered fatal errors and immediately deactivate

;     the TD without decrementing this field. 0 = no error limit,

;     n = deactivate the TD after n errors.

; 14. Next bit (bit 29) is ShortPacketDetect bit. 1 = short packet is an error.

;     Note: the specification defines this bit as input for the controller,

;     but does not specify the value written by controller.

;     Some controllers (e.g. Intel) keep the value, some controllers (e.g. VIA)

;     set the value to whether a short packet was actually detected

;     (or something like that).

;     Thus, we duplicate this bit as bit 0 of OrigBufferInfo.

; 15. Upper two bits (bits 30-31) are reserved.

Token           dd      ?

; 1. Lower 8 bits (bits 0-7) are PID, one of USB_PID_*.

; 2. Next 7 bits (bits 8-14) are DeviceAddress field. This is the address of

;    the target device on the USB bus.

; 3. Next 4 bits (bits 15-18) are Endpoint field. This is the target endpoint

;    number.

; 4. Next bit (bit 19) is DataToggle bit. n = issue/expect DATAn token.

; 5. Next bit (bit 20) is reserved.

; 6. Upper 11 bits (bits 21-31) are MaximumLength field. This field specifies

;    the maximum number of data bytes for the transfer minus 1 byte. Null data

;    packet is encoded as 0x7FF, maximum possible non-null data packet is 1280

;    bytes, encoded as 0x4FF.

Buffer          dd      ?

; Physical address of the data buffer for this TD.

OrigBufferInfo  dd      ?

; Usually NULL. If the original buffer crosses a page boundary, this is a

; pointer to the structure uhci_original_buffer for this request.

; bit 0: 1 = short packet is NOT allowed

; (before the TD is processed, it is the copy of bit 29 of ControlStatus;

;  some controllers modify that bit, so we need a copy in a safe place)

SoftwarePart    rd      sizeof.usb_gtd/4

; Software part, common for all controllers.

ends

if sizeof.uhci_gtd mod 16

.err uhci_gtd must be 16-bytes aligned

end if

; UHCI requires that the entire transfer buffer should be on one page.

; If the actual buffer crosses page boundary, uhci_alloc_packet

; allocates additional memory for buffer for hardware.

; This structure describes correspondence between two buffers.

struct uhci_original_buffer

OrigBuffer      dd      ?

UsedBuffer      dd      ?

ends

; Description of UHCI-specific data and functions for

; controller-independent code.

; Implements the structure usb_hardware_func from hccommon.inc for UHCI.

iglobal

align 4

uhci_hardware_func:

        dd      'UHCI'

        dd      sizeof.uhci_controller

        dd      uhci_init

        dd      uhci_process_deferred

        dd      uhci_set_device_address

        dd      uhci_get_device_address

        dd      uhci_port_disable

        dd      uhci_new_port.reset

        dd      uhci_set_endpoint_packet_size

        dd      usb1_allocate_endpoint

        dd      uhci_free_pipe

        dd      uhci_init_pipe

        dd      uhci_unlink_pipe

        dd      usb1_allocate_general_td

        dd      uhci_free_td

        dd      uhci_alloc_transfer

        dd      uhci_insert_transfer

        dd      uhci_new_device

endg

; =============================================================================

; =================================== Code ====================================

; =============================================================================

; Controller-specific initialization function.

; Called from usb_init_controller. Initializes the hardware and

; UHCI-specific parts of software structures.

; eax = pointer to uhci_controller to be initialized

; [ebp-4] = pcidevice

proc uhci_init

; inherit some variables from the parent (usb_init_controller)

.devfn   equ ebp - 4

.bus     equ ebp - 3

; 1. Store pointer to uhci_controller for further use.

        push    eax

        mov     edi, eax

        mov     esi, eax

; 2. Initialize uhci_controller.FrameList.

; Note that FrameList is located in the beginning of uhci_controller,

; so esi and edi now point to uhci_controller.FrameList.

; First 32 entries of FrameList contain physical addresses

; of first 32 Periodic static heads, further entries duplicate these.

; See the description of structures for full info.

; Note that all static heads fit in one page, so one call to

; get_phys_addr is sufficient.

if (uhci_controller.IntEDs / 0x1000) <> (uhci_controller.BulkED / 0x1000)

.err assertion failed

end if

; 2a. Get physical address of first static head.

; Note that 1) it is located in the beginning of a page

; and 2) all other static heads fit in the same page,

; so one call to get_phys_addr without correction of lower 12 bits

; is sufficient.

if (uhci_controller.IntEDs mod 0x1000) <> 0

.err assertion failed

end if

        add     eax, uhci_controller.IntEDs

        call    get_phys_addr

; 2b. Fill first 32 entries.

        inc     eax

        inc     eax     ; set QH bit for uhci_pipe.NextQH

        movi    ecx, 32

        mov     edx, ecx

@@:

        stosd

        add     eax, sizeof.uhci_static_ep

        loop    @b

; 2c. Fill the rest entries.

        mov     ecx, 1024 - 32

        rep movsd

; 3. Initialize static heads uhci_controller.*ED.

; Use the loop over groups: first group consists of first 32 Periodic

; descriptors, next group consists of next 16 Periodic descriptors,

; ..., last group consists of the last Periodic descriptor.

; 3a. Prepare for the loop.

; make esi point to the second group, other registers are already set.

        add     esi, 32*4 + 32*sizeof.uhci_static_ep

; 3b. Loop over groups. On every iteration:

; edx = size of group, edi = pointer to the current group,

; esi = pointer to the next group, eax = physical address of the next group.

.init_static_eds:

; 3c. Get the size of next group.

        shr     edx, 1

; 3d. Exit the loop if there is no next group.

        jz      .init_static_eds_done

; 3e. Initialize the first half of the current group.

; Advance edi to the second half.

        push    eax esi

        call    uhci_init_static_ep_group

        pop     esi eax

; 3f. Initialize the second half of the current group

; with the same values.

; Advance edi to the next group, esi/eax to the next of the next group.

        call    uhci_init_static_ep_group

        jmp     .init_static_eds

.init_static_eds_done:

; 3g. Initialize the last static head.

        xor     esi, esi

        call    uhci_init_static_endpoint

; 3i. Initialize the head of Control list.

        add     eax, sizeof.uhci_static_ep

        call    uhci_init_static_endpoint

; 3j. Initialize the head of Bulk list.

        sub     eax, sizeof.uhci_static_ep

        call    uhci_init_static_endpoint

; 4. Get I/O base address and size from PCI bus.

; 4a. Read&save PCI command state.

        mov     bh, [.devfn]

        mov     ch, [.bus]

        mov     cl, 1

        mov     eax, ecx

        mov     bl, 4

        call    pci_read_reg

        push    eax

; 4b. Disable IO access.

        and     al, not 1

        push    ecx

        xchg    eax, ecx

        call    pci_write_reg

        pop     ecx

; 4c. Read&save IO base address.

        mov     eax, ecx

        mov     bl, 20h

        call    pci_read_reg

        and     al, not 3

        xchg    eax, edi

; now edi = IO base

; 4d. Write 0xffff to IO base address.

        push    ecx

        xchg    eax, ecx

        or      ecx, -1

        call    pci_write_reg

        pop     ecx

; 4e. Read IO base address.

        mov     eax, ecx

        call    pci_read_reg

        and     al, not 3

        cwde

        not     eax

        inc     eax

        xchg    eax, esi

; now esi = IO size

; 4f. Restore IO base address.

        xchg    eax, ecx

        mov     ecx, edi

        push    eax

        call    pci_write_reg

        pop     eax

; 4g. Restore PCI command state and enable io & bus master access.

        pop     ecx

        or      ecx, 5

        mov     bl, 4

        push    eax

        call    pci_write_reg

        pop     eax

; 5. Reset the controller.

; 5e. Host reset.

        mov     edx, edi

        mov     ax, 2

        out     dx, ax

; 5f. Wait up to 10ms.

        movi    ecx, 10

@@:

        push    esi

        movi    esi, 1

        call    delay_ms

        pop     esi

        in      ax, dx

        test    al, 2

        loopnz  @b

        jz      @f

        dbgstr 'UHCI controller reset timeout'

        jmp     .fail

@@:

if 0

; emergency variant for tests - always wait 10 ms

; wait 10 ms

        push    esi

        movi    esi, 10

        call    delay_ms

        pop     esi

; clear reset signal

        xor     eax, eax

        out     dx, ax

end if

.resetok:

; 6. Get number of ports & disable all ports.

        add     esi, edi

        lea     edx, [edi+UhciPort1StatusReg]

.scanports:

        cmp     edx, esi

        jae     .doneports

        in      ax, dx

        cmp     ax, 0xFFFF

        jz      .doneports

        test    al, al

        jns     .doneports

        xor     eax, eax

        out     dx, ax

        inc     edx

        inc     edx

        jmp     .scanports

.doneports:

        lea     esi, [edx-UhciPort1StatusReg]

        sub     esi, edi

        shr     esi, 1  ; esi = number of ports

        jnz     @f

        dbgstr 'error: no ports on UHCI controller'

        jmp     .fail

@@:

; 7. Setup the rest of uhci_controller.

        xchg    esi, [esp]      ; restore the pointer to uhci_controller from the step 1

        add     esi, sizeof.uhci_controller

        pop     [esi+usb_controller.NumPorts]

        DEBUGF 1,'K : UHCI controller at %x:%x with %d ports initialized\n',[.bus]:2,[.devfn]:2,[esi+usb_controller.NumPorts]

        mov     [esi+uhci_controller.IOBase-sizeof.uhci_controller], edi

        mov     eax, [timer_ticks]

        mov     [esi+uhci_controller.LastPollTime-sizeof.uhci_controller], eax

; 8. Hook interrupt.

        mov     ah, [.bus]

        mov     al, 0

        mov     bh, [.devfn]

        mov     bl, 3Ch

        call    pci_read_reg

; al = IRQ

;       DEBUGF 1,'K : UHCI %x: io=%x, irq=%x\n',esi,edi,al

        movzx   eax, al

        stdcall attach_int_handler, eax, uhci_irq, esi

; 9. Setup controller registers.

        xor     eax, eax

        mov     edx, [esi+uhci_controller.IOBase-sizeof.uhci_controller]

; 9a. UhciStatusReg := 3Fh: clear all status bits

; (for this register 1 clears the corresponding bit, 0 does not change it).

        inc     edx

        inc     edx     ; UhciStatusReg == 2

        mov     al, 3Fh

        out     dx, ax

; 9b. UhciInterruptReg := 0Dh.

        inc     edx

        inc     edx     ; UhciInterruptReg == 4

        mov     al, 0Dh

        out     dx, ax

; 9c. UhciFrameNumberReg := 0.

        inc     edx

        inc     edx     ; UhciFrameNumberReg == 6

        mov     al, 0

        out     dx, ax

; 9d. UhciBaseAddressReg := physical address of uhci_controller.

        inc     edx

        inc     edx     ; UhciBaseAddressReg == 8

        lea     eax, [esi-sizeof.uhci_controller]

        call    get_phys_addr

        out     dx, eax

; 9e. UhciCommandReg := Run + Configured + (MaxPacket is 64 bytes)

        sub     edx, UhciBaseAddressReg ; UhciCommandReg == 0

        mov     ax, 0C1h        ; Run, Configured, MaxPacket = 64b

        out     dx, ax

; 10. Do initial scan of existing devices.

        call    uhci_poll_roothub

; 11. Return pointer to usb_controller.

        xchg    eax, esi

        ret

.fail:

; On error, pop the pointer saved at step 1 and return zero.

; Note that the main code branch restores the stack at step 7 and never fails

; after step 7.

        pop     ecx

        xor     eax, eax

        ret

endp

; Controller-specific pre-initialization function: take ownership from BIOS.

; UHCI has no mechanism to ask the owner politely to release ownership,

; so do it in inpolite way, preventing controller from any SMI activity.

proc uhci_kickoff_bios

; 1. Get the I/O address.

        mov     ah, [esi+PCIDEV.bus]

        mov     al, 1

        mov     bh, [esi+PCIDEV.devfn]

        mov     bl, 20h

        call    pci_read_reg

        and     eax, 0xFFFC

        xchg    eax, edx

; 2. Stop the controller and disable all interrupts.

        in      ax, dx

        and     al, not 1

        out     dx, ax

        add     edx, UhciInterruptReg

        xor     eax, eax

        out     dx, ax

; 3. Disable all bits for SMI routing, clear SMI routing status,

; enable master interrupt bit.

        mov     ah, [esi+PCIDEV.bus]

        mov     al, 1

        mov     bl, 0xC0

        mov     ecx, 0AF00h

        call    pci_write_reg

        ret

endp

; Helper procedure for step 3 of uhci_init.

; Initializes the static head of one list.

; eax = physical address of the "next" list, esi = pointer to the "next" list,

; edi = pointer to head to initialize.

; Advances edi to the next head, keeps eax/esi.

proc uhci_init_static_endpoint

        mov     [edi+uhci_static_ep.NextQH], eax

        mov     byte [edi+uhci_static_ep.HeadTD], 1

        mov     [edi+uhci_static_ep.NextList], esi

        add     edi, uhci_static_ep.SoftwarePart

        call    usb_init_static_endpoint

        add     edi, sizeof.uhci_static_ep - uhci_static_ep.SoftwarePart

        ret

endp

; Helper procedure for step 3 of uhci_init, see comments there.

; Initializes one half of group of static heads.

; edx = size of the next group = half of size of the group,

; edi = pointer to the group, eax = physical address of the next group,

; esi = pointer to the next group.

; Advances eax, esi, edi to next group, keeps edx.

proc uhci_init_static_ep_group

        push    edx

@@:

        call    uhci_init_static_endpoint

        add     eax, sizeof.uhci_static_ep

        add     esi, sizeof.uhci_static_ep

        dec     edx

        jnz     @b

        pop     edx

        ret

endp

; IRQ handler for UHCI controllers.

uhci_irq.noint:

; Not our interrupt: restore esi and return zero.

        pop     esi

        xor     eax, eax

        ret

proc uhci_irq

        push    esi     ; save used register to be cdecl

virtual at esp

                dd      ?       ; saved esi

                dd      ?       ; return address

.controller     dd      ?

end virtual

        mov     esi, [.controller]

; 1. Read UhciStatusReg.

        mov     edx, [esi+uhci_controller.IOBase-sizeof.uhci_controller]

        inc     edx

        inc     edx     ; UhciStatusReg == 2

        in      ax, dx

; 2. Test whether it is our interrupt; if so, at least one status bit is set.

        test    al, 0x1F

        jz      .noint

; 3. Clear all status bits.

        out     dx, ax

; 4. Sanity check.

        test    al, 0x3C

        jz      @f

        DEBUGF 1,'K : something terrible happened with UHCI (%x)\n',al

@@:

; 5. We can't do too much from an interrupt handler, e.g. we can't take

; any mutex locks since our code could be called when another code holds the

; lock and has no chance to release it. Thus, only inform the processing thread

; that it should scan the queue and wake it if needed.

        lock or byte [esi+uhci_controller.DeferredActions-sizeof.uhci_controller], al

        push    ebx

        xor     ebx, ebx

        inc     ebx

        call    usb_wakeup_if_needed

        pop     ebx

; 6. This is our interrupt; return 1.

        mov     al, 1

        pop     esi     ; restore used register to be stdcall

        ret

endp

; This procedure is called in the USB thread from usb_thread_proc,

; processes regular actions and those actions which can't be safely done

; from interrupt handler.

; Returns maximal time delta before the next call.

proc uhci_process_deferred

        push    ebx edi         ; save used registers to be stdcall

; 1. Initialize the return value.

        push    -1

; 2. Poll the root hub every UHCI_POLL_INTERVAL ticks.

; Also force polling if some transaction has completed with errors;

; the error can be caused by disconnect, try to detect it.

        test    byte [esi+uhci_controller.DeferredActions-sizeof.uhci_controller], 2

        jnz     .force_poll

        mov     eax, [timer_ticks]

        sub     eax, [esi+uhci_controller.LastPollTime-sizeof.uhci_controller]

        sub     eax, UHCI_POLL_INTERVAL

        jl      .nopoll

.force_poll:

        mov     eax, [timer_ticks]

        mov     [esi+uhci_controller.LastPollTime-sizeof.uhci_controller], eax

        call    uhci_poll_roothub

        mov     eax, -UHCI_POLL_INTERVAL

.nopoll:

        neg     eax

        cmp     [esp], eax

        jb      @f

        mov     [esp], eax

@@:

; 3. Process wait lists.

; 3a. Test whether there is a wait request.

        mov     eax, [esi+usb_controller.WaitPipeRequestAsync]

        cmp     eax, [esi+usb_controller.ReadyPipeHeadAsync]

        jnz     .check_removed

        mov     eax, [esi+usb_controller.WaitPipeRequestPeriodic]

        cmp     eax, [esi+usb_controller.ReadyPipeHeadPeriodic]

        jz      @f

.check_removed:

; 3b. Yep. Find frame and compare it with the saved one.

        mov     edx, [esi+uhci_controller.IOBase-sizeof.uhci_controller]

        add     edx, UhciFrameNumberReg

        in      ax, dx

        cmp     word [esi+usb_controller.StartWaitFrame], ax

        jnz     .removed

; 3c. The same frame; wake up in 0.01 sec.

        mov     dword [esp], 1

        jmp     @f

.removed:

; 3d. The frame is changed, old contents is guaranteed to be forgotten.

        mov     eax, [esi+usb_controller.WaitPipeRequestAsync]

        mov     [esi+usb_controller.ReadyPipeHeadAsync], eax

        mov     eax, [esi+usb_controller.WaitPipeRequestPeriodic]

        mov     [esi+usb_controller.ReadyPipeHeadPeriodic], eax

@@:

; 4. Process disconnect events. This should be done after step 2

; (which includes the first stage of disconnect processing).

        call    usb_disconnect_stage2

; 5. Test whether USB_CONNECT_DELAY for a connected device is over.

; Call uhci_new_port for all such devices.

        xor     ecx, ecx

        cmp     [esi+usb_controller.NewConnected], ecx

        jz      .skip_newconnected

.portloop:

        bt      [esi+usb_controller.NewConnected], ecx

        jnc     .noconnect

        mov     eax, [timer_ticks]

        sub     eax, [esi+usb_controller.ConnectedTime+ecx*4]

        sub     eax, USB_CONNECT_DELAY

        jge     .connected

        neg     eax

        cmp     [esp], eax

        jb      .nextport

        mov     [esp], eax

        jmp     .nextport

.connected:

        btr     [esi+usb_controller.NewConnected], ecx

        call    uhci_new_port

.noconnect:

.nextport:

        inc     ecx

        cmp     ecx, [esi+usb_controller.NumPorts]

        jb      .portloop

.skip_newconnected:

; 6. Test for processed packets.

; This should be done after step 4, so transfers which were failed due

; to disconnect are marked with the exact reason, not just

; 'device not responding'.

        xor     eax, eax

        xchg    byte [esi+uhci_controller.DeferredActions-sizeof.uhci_controller], al

        test    al, 3

        jz      .noioc

        call    uhci_process_updated_schedule

.noioc:

; 7. Test whether reset signalling has been started. If so,

; either should be stopped now (if time is over) or schedule wakeup (otherwise).

; This should be done after step 6, because a completed SET_ADDRESS command

; could result in reset of a new port.

.test_reset:

; 7a. Test whether reset signalling is active.

        cmp     [esi+usb_controller.ResettingStatus], 1

        jnz     .no_reset_in_progress

; 7b. Yep. Test whether it should be stopped.

        mov     eax, [timer_ticks]

        sub     eax, [esi+usb_controller.ResetTime]

        sub     eax, USB_RESET_TIME

        jge     .reset_done

; 7c. Not yet, but initiate wakeup in -eax ticks and exit this step.

        neg     eax

        cmp     [esp], eax

        jb      .skip_reset

        mov     [esp], eax

        jmp     .skip_reset

.reset_done:

; 7d. Yep, call the worker function and proceed to 7e.

        call    uhci_port_reset_done

.no_reset_in_progress:

; 7e. Test whether reset process is done, either successful or failed.

        cmp     [esi+usb_controller.ResettingStatus], 0

        jz      .skip_reset

; 7f. Yep. Test whether it should be stopped.

        mov     eax, [timer_ticks]

        sub     eax, [esi+usb_controller.ResetTime]

        sub     eax, USB_RESET_RECOVERY_TIME

        jge     .reset_recovery_done

; 7g. Not yet, but initiate wakeup in -eax ticks and exit this step.

        neg     eax

        cmp     [esp], eax

        jb      .skip_reset

        mov     [esp], eax

        jmp     .skip_reset

.reset_recovery_done:

; 7h. Yep, call the worker function. This could initiate another reset,

; so return to the beginning of this step.

        call    uhci_port_init

        jmp     .test_reset

.skip_reset:

; 8. Process wait-done notifications, test for new wait requests.

; Note: that must be done after steps 4 and 6 which could create new requests.

; 8a. Call the worker function.

        call    usb_process_wait_lists

; 8b. If no new requests, skip the rest of this step.

        test    eax, eax

        jz      @f

; 8c. UHCI is not allowed to cache anything; we don't know what is

; processed right now, but we can be sure that the controller will not

; use any removed structure starting from the next frame.

; Request removal of everything disconnected until now,

; schedule wakeup in 0.01 sec.

        mov     eax, [esi+usb_controller.WaitPipeListAsync]

        mov     [esi+usb_controller.WaitPipeRequestAsync], eax

        mov     eax, [esi+usb_controller.WaitPipeListPeriodic]

        mov     [esi+usb_controller.WaitPipeRequestPeriodic], eax

        mov     edx, [esi+uhci_controller.IOBase-sizeof.uhci_controller]

        add     edx, UhciFrameNumberReg

        in      ax, dx

        mov     word [esi+usb_controller.StartWaitFrame], ax

        mov     dword [esp], 1

@@:

; 9. Return the value from the top of stack.

        pop     eax

        pop     edi ebx         ; restore used registers to be stdcall.

        ret

endp

; This procedure is called in the USB thread from uhci_process_deferred

; when UHCI IRQ handler has signalled that new IOC-packet was processed.

; It scans all lists for completed packets and calls uhci_process_finalized_td

; for those packets.

; in: esi -> usb_controller

proc uhci_process_updated_schedule

; Important note: we cannot hold the list lock during callbacks,

; because callbacks sometimes open and/or close pipes and thus acquire/release

; the corresponding lock itself.

; Fortunately, pipes can be finally freed only by another step of

; uhci_process_deferred, so all pipes existing at the start of this function

; will be valid while this function is running. Some pipes can be removed

; from the corresponding list, some pipes can be inserted; insert/remove

; functions guarantee that traversing one list yields all pipes that were in

; that list at the beginning of the traversing (possibly with some new pipes,

; possibly without some new pipes, that doesn't matter).

; 1. Process all Periodic lists.

        lea     edi, [esi+uhci_controller.IntEDs.SoftwarePart-sizeof.uhci_controller]

        lea     ebx, [esi+uhci_controller.IntEDs.SoftwarePart+63*sizeof.uhci_static_ep-sizeof.uhci_controller]

@@:

        call    uhci_process_updated_list

        cmp     edi, ebx

        jnz     @b

; 2. Process the Control list.

        call    uhci_process_updated_list

; 3. Process the Bulk list.

        call    uhci_process_updated_list

; 4. Return.

        ret

endp

; This procedure is called from uhci_process_updated_schedule,

; see comments there.

; It processes one list, esi -> usb_controller, edi -> usb_static_ep,

; and advances edi to the next head.

proc uhci_process_updated_list

        push    ebx             ; save used register to be stdcall

; 1. Perform the external loop over all pipes.

        mov     ebx, [edi+usb_static_ep.NextVirt]

.loop:

        cmp     ebx, edi

        jz      .done

; store pointer to the next pipe in the stack

        push    [ebx+usb_static_ep.NextVirt]

; 2. For every pipe, perform the internal loop over all descriptors.

; All descriptors are organized in the queue; we process items from the start

; of the queue until a) the last descriptor (not the part of the queue itself)

; or b) an active (not yet processed by the hardware) descriptor is reached.

        lea     ecx, [ebx+usb_pipe.Lock]

        call    mutex_lock

        mov     ebx, [ebx+usb_pipe.LastTD]

        push    ebx

        mov     ebx, [ebx+usb_gtd.NextVirt]

.tdloop:

; 3. For every descriptor, test active flag and check for end-of-queue;

; if either of conditions holds, exit from the internal loop.

        cmp     ebx, [esp]

        jz      .tddone

        mov     eax, [ebx+uhci_gtd.ControlStatus-uhci_gtd.SoftwarePart]

        test    eax, 1 shl 23   ; active?

        jnz     .tddone

; Release the queue lock while processing one descriptor:

; callback function could (and often would) schedule another transfer.

        push    ecx

        call    mutex_unlock

        call    uhci_process_finalized_td

        pop     ecx

        call    mutex_lock

        jmp     .tdloop

.tddone:

        call    mutex_unlock

        pop     ebx

; End of internal loop, restore pointer to the next pipe

; and continue the external loop.

        pop     ebx

        jmp     .loop

.done:

        pop     ebx             ; restore used register to be stdcall

        add     edi, sizeof.uhci_static_ep

        ret

endp

; This procedure is called from uhci_process_updated_list, which is itself

; called from uhci_process_updated_schedule, see comments there.

; It processes one completed descriptor.

; in: esi -> usb_controller, ebx -> usb_gtd, out: ebx -> next usb_gtd.

proc uhci_process_finalized_td

; 1. Remove this descriptor from the list of descriptors for this pipe.

        call    usb_unlink_td

;       DEBUGF 1,'K : finalized TD:\n'

;       DEBUGF 1,'K : %x %x %x %x\n',[ebx-20],[ebx-16],[ebx-12],[ebx-8]

;       DEBUGF 1,'K : %x %x %x %x\n',[ebx-4],[ebx],[ebx+4],[ebx+8]

; 2. If this is IN transfer into special buffer, copy the data

; to target location.

        mov     edx, [ebx+uhci_gtd.OrigBufferInfo-uhci_gtd.SoftwarePart]

        and     edx, not 1      ; clear lsb (used for another goal)

        jz      .nocopy

        cmp     byte [ebx+uhci_gtd.Token-uhci_gtd.SoftwarePart], USB_PID_IN

        jnz     .nocopy

; Note: we assume that pointer to buffer is valid in the memory space of

; the USB thread. This means that buffer must reside in kernel memory

; (shared by all processes).

        push    esi edi

        mov     esi, [edx+uhci_original_buffer.UsedBuffer]

        mov     edi, [edx+uhci_original_buffer.OrigBuffer]

        mov     ecx, [ebx+uhci_gtd.ControlStatus-uhci_gtd.SoftwarePart]

        inc     ecx

        and     ecx, 7FFh

        mov     edx, ecx

        shr     ecx, 2

        and     edx, 3

        rep movsd

        mov     ecx, edx

        rep movsb

        pop     edi esi

.nocopy:

; 3. Calculate actual number of bytes transferred.

; 3a. Read the state.

        mov     eax, [ebx+uhci_gtd.ControlStatus-uhci_gtd.SoftwarePart]

        mov     ecx, [ebx+uhci_gtd.Token-uhci_gtd.SoftwarePart]

; 3b. Get number of bytes processed.

        lea     edx, [eax+1]

        and     edx, 7FFh

; 3c. Subtract number of bytes in this packet.

        add     ecx, 1 shl 21

        shr     ecx, 21

        sub     edx, ecx

; 3d. Add total length transferred so far.

        add     edx, [ebx+usb_gtd.Length]

; Actions on error and on success are slightly different.

; 4. Test for error. On error, proceed to step 5, otherwise go to step 6

; with ecx = 0 (no error).

; USB transaction error is always considered as such.

; If short packets are not allowed, UHCI controllers do not set an error bit,

; but stop (clear Active bit and do not advance) the queue.

; Short packet is considered as an error if the packet is actually short

; (actual length is less than maximal one) and the code creating the packet

; requested that behaviour (so bit 0 of OrigBufferInfo is set; this could be

; because the caller disallowed short packets or because the packet is not

; the last one in the corresponding transfer).

        xor     ecx, ecx

        test    eax, 1 shl 22

        jnz     .error

        test    byte [ebx+uhci_gtd.OrigBufferInfo-uhci_gtd.SoftwarePart], 1

        jz      .notify

        cmp     edx, [ebx+usb_gtd.Length]

        jz      .notify

.error:

; 5. There was an error while processing this packet.

; The hardware has stopped processing the queue.

        DEBUGF 1,'K : TD failed:\n'

if uhci_gtd.SoftwarePart <> 20

.err modify offsets for debug output

end if

        DEBUGF 1,'K : %x %x %x %x\n',[ebx-20],[ebx-16],[ebx-12],[ebx-8]

        DEBUGF 1,'K : %x %x %x %x\n',[ebx-4],[ebx],[ebx+4],[ebx+8]

; 5a. Save the status and length.

        push    edx

        push    eax

        mov     eax, [ebx+usb_gtd.Pipe]

        DEBUGF 1,'K : pipe: %x %x\n',[eax+0-uhci_pipe.SoftwarePart],[eax+4-uhci_pipe.SoftwarePart]

; 5b. Store the current TD as an error packet.

; If an error packet is already stored for this pipe,

; it is definitely not used already, so free the old packet.

        mov     eax, [eax+uhci_pipe.ErrorTD-uhci_pipe.SoftwarePart]

        test    eax, eax

        jz      @f

        stdcall uhci_free_td, eax

@@:

        mov     eax, [ebx+usb_gtd.Pipe]

        mov     [eax+uhci_pipe.ErrorTD-uhci_pipe.SoftwarePart], ebx

; 5c. Traverse the list of descriptors looking for the final packet

; for this transfer.

; Free and unlink non-final descriptors, except the current one.

; Final descriptor will be freed in step 7.

        call    usb_is_final_packet

        jnc     .found_final

        mov     ebx, [ebx+usb_gtd.NextVirt]

.look_final:

        call    usb_unlink_td

        call    usb_is_final_packet

        jnc     .found_final

        push    [ebx+usb_gtd.NextVirt]

        stdcall uhci_free_td, ebx

        pop     ebx

        jmp     .look_final

.found_final:

; 5d. Restore the status saved in 5a and transform it to the error code.

        pop     eax     ; error code

        shr     eax, 16

; Notes:

; * any USB transaction error results in Stalled bit; if it is not set,

;   but we are here, it must be due to short packet;

; * babble is considered a fatal USB transaction error,

;   other errors just lead to retrying the transaction;

;   if babble is detected, return the corresponding error;

; * if several non-fatal errors have occured during transaction retries,

;   all corresponding bits are set. In this case, return some error code,

;   the order is quite arbitrary.

        movi    ecx, USB_STATUS_UNDERRUN

        test    al, 1 shl (22-16)       ; not Stalled?

        jz      .know_error

        mov     cl, USB_STATUS_OVERRUN

        test    al, 1 shl (20-16)       ; Babble detected?

        jnz     .know_error

        mov     cl, USB_STATUS_BITSTUFF

        test    al, 1 shl (17-16)       ; Bitstuff error?

        jnz     .know_error

        mov     cl, USB_STATUS_NORESPONSE

        test    al, 1 shl (18-16)       ; CRC/TimeOut error?

        jnz     .know_error

        mov     cl, USB_STATUS_BUFOVERRUN

        test    al, 1 shl (21-16)       ; Data Buffer error?

        jnz     .know_error

        mov     cl, USB_STATUS_STALL

.know_error:

; 5e. If error code is USB_STATUS_UNDERRUN

; and the last TD allows short packets, it is not an error.

; Note: all TDs except the last one in any transfer stage are marked

; as short-packet-is-error to stop controller from further processing

; of that stage; we need to restart processing from a TD following the last.

; After that, go to step 6 with ecx = 0 (no error).

        cmp     ecx, USB_STATUS_UNDERRUN

        jnz     @f

        test    byte [ebx+uhci_gtd.OrigBufferInfo-uhci_gtd.SoftwarePart], 1

        jnz     @f

; The controller has stopped this queue on the error packet.

; Update uhci_pipe.HeadTD to point to the next packet in the queue.

        call    uhci_fix_toggle

        xor     ecx, ecx

.control:

        mov     eax, [ebx+uhci_gtd.NextTD-uhci_gtd.SoftwarePart]

        and     al, not 0xF

        mov     edx, [ebx+usb_gtd.Pipe]

        mov     [edx+uhci_pipe.HeadTD-uhci_pipe.SoftwarePart], eax

        pop     edx     ; length

        jmp     .notify

@@:

; 5f. Abort the entire transfer.

; There are two cases: either there is only one transfer stage

; (everything except control transfers), then ebx points to the last TD and

; all previous TD were unlinked and dismissed (if possible),

; or there are several stages (a control transfer) and ebx points to the last

; TD of Data or Status stage (usb_is_final_packet does not stop in Setup stage,

; because Setup stage can not produce short packets); for Data stage, we need

; to unlink and free (if possible) one more TD and advance ebx to the next one.

        cmp     [ebx+usb_gtd.Callback], 0

        jnz     .normal

; We cannot free ErrorTD yet, it could still be used by the hardware.

        push    ecx

        mov     eax, [ebx+usb_gtd.Pipe]

        push    [ebx+usb_gtd.NextVirt]

        cmp     ebx, [eax+uhci_pipe.ErrorTD-uhci_pipe.SoftwarePart]

        jz      @f

        stdcall uhci_free_td, ebx

@@:

        pop     ebx

        call    usb_unlink_td

        pop     ecx

.normal:

; 5g. For bulk/interrupt transfers we have no choice but halt the queue,

; the driver should intercede (through some API which is not written yet).

; Control pipes normally recover at the next SETUP transaction (first stage

; of any control transfer), so we hope on the best and just advance the queue

; to the next transfer. (According to the standard, "A control pipe may also

; support functional stall as well, but this is not recommended.").

        mov     edx, [ebx+usb_gtd.Pipe]

        cmp     [edx+usb_pipe.Type], CONTROL_PIPE

        jz      .control

; Bulk/interrupt transfer; halt the queue.

        mov     eax, [ebx+uhci_gtd.NextTD-uhci_gtd.SoftwarePart]

        and     al, not 0xF

        inc     eax     ; set Halted bit

        mov     [edx+uhci_pipe.HeadTD-uhci_pipe.SoftwarePart], eax

        pop     edx     ; restore length saved in step 5a

.notify:

; 6. Either the descriptor in ebx was processed without errors,

; or all necessary error actions were taken and ebx points to the last

; related descriptor.

; 6a. Test whether it is the last packet in the transfer

; <=> it has an associated callback.

        mov     eax, [ebx+usb_gtd.Callback]

        test    eax, eax

        jz      .nocallback

; 6b. It has an associated callback; call it with corresponding parameters.

        stdcall_verify eax, [ebx+usb_gtd.Pipe], ecx, \

                [ebx+usb_gtd.Buffer], edx, [ebx+usb_gtd.UserData]

        jmp     .callback

.nocallback:

; 6c. It is an intermediate packet. Add its length to the length

; in the following packet.

        mov     eax, [ebx+usb_gtd.NextVirt]

        add     [eax+usb_gtd.Length], edx

.callback:

; 7. Free the current descriptor (if allowed) and return the next one.

; 7a. Save pointer to the next descriptor.

        push    [ebx+usb_gtd.NextVirt]

; 7b. Free the descriptor, unless it is saved as ErrorTD.

        mov     eax, [ebx+usb_gtd.Pipe]

        cmp     [eax+uhci_pipe.ErrorTD-uhci_pipe.SoftwarePart], ebx

        jz      @f

        stdcall uhci_free_td, ebx

@@:

; 7c. Restore pointer to the next descriptor and return.

        pop     ebx

        ret

endp

; Helper procedure for restarting transfer queue.

; When transfers are queued, their toggle bit is filled assuming that

; everything will go without errors. On error, some packets needs to be

; skipped, so toggle bits may become incorrect.

; This procedure fixes toggle bits.

; in: ebx -> last packet to be skipped, ErrorTD -> last processed packet

proc uhci_fix_toggle

; 1. Nothing to do for control pipes: in that case,

; toggle bits for different transfer stages are independent.

        mov     ecx, [ebx+usb_gtd.Pipe]

        cmp     [ecx+usb_pipe.Type], CONTROL_PIPE

        jz      .nothing

; 2. The hardware expects next packet with toggle = (ErrorTD.toggle xor 1),

; the current value in next packet is (ebx.toggle xor 1).

; Nothing to do if ErrorTD.toggle == ebx.toggle.

        mov     eax, [ecx+uhci_pipe.ErrorTD-uhci_pipe.SoftwarePart]

        mov     eax, [eax+uhci_gtd.Token-uhci_gtd.SoftwarePart]

        xor     eax, [ebx+uhci_gtd.Token-uhci_gtd.SoftwarePart]

        test    eax, 1 shl 19

        jz      .nothing

; 3. Lock the transfer queue.

        add     ecx, usb_pipe.Lock