linux/drivers/gpu/drm/nouveau/nvc0_grhub.fuc

812 lines
18 KiB
Plaintext

/* fuc microcode for nvc0 PGRAPH/HUB
*
* Copyright 2011 Red Hat Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
* Authors: Ben Skeggs
*/
/* To build:
* m4 nvc0_grhub.fuc | envyas -a -w -m fuc -V nva3 -o nvc0_grhub.fuc.h
*/
.section nvc0_grhub_data
include(`nvc0_graph.fuc')
gpc_count: .b32 0
rop_count: .b32 0
cmd_queue: queue_init
hub_mmio_list_head: .b32 0
hub_mmio_list_tail: .b32 0
ctx_current: .b32 0
chipsets:
.b8 0xc0 0 0 0
.b16 nvc0_hub_mmio_head
.b16 nvc0_hub_mmio_tail
.b8 0xc1 0 0 0
.b16 nvc0_hub_mmio_head
.b16 nvc1_hub_mmio_tail
.b8 0xc3 0 0 0
.b16 nvc0_hub_mmio_head
.b16 nvc0_hub_mmio_tail
.b8 0xc4 0 0 0
.b16 nvc0_hub_mmio_head
.b16 nvc0_hub_mmio_tail
.b8 0xc8 0 0 0
.b16 nvc0_hub_mmio_head
.b16 nvc0_hub_mmio_tail
.b8 0xce 0 0 0
.b16 nvc0_hub_mmio_head
.b16 nvc0_hub_mmio_tail
.b8 0xcf 0 0 0
.b16 nvc0_hub_mmio_head
.b16 nvc0_hub_mmio_tail
.b8 0 0 0 0
nvc0_hub_mmio_head:
mmctx_data(0x17e91c, 2)
mmctx_data(0x400204, 2)
mmctx_data(0x404004, 11)
mmctx_data(0x404044, 1)
mmctx_data(0x404094, 14)
mmctx_data(0x4040d0, 7)
mmctx_data(0x4040f8, 1)
mmctx_data(0x404130, 3)
mmctx_data(0x404150, 3)
mmctx_data(0x404164, 2)
mmctx_data(0x404174, 3)
mmctx_data(0x404200, 8)
mmctx_data(0x404404, 14)
mmctx_data(0x404460, 4)
mmctx_data(0x404480, 1)
mmctx_data(0x404498, 1)
mmctx_data(0x404604, 4)
mmctx_data(0x404618, 32)
mmctx_data(0x404698, 21)
mmctx_data(0x4046f0, 2)
mmctx_data(0x404700, 22)
mmctx_data(0x405800, 1)
mmctx_data(0x405830, 3)
mmctx_data(0x405854, 1)
mmctx_data(0x405870, 4)
mmctx_data(0x405a00, 2)
mmctx_data(0x405a18, 1)
mmctx_data(0x406020, 1)
mmctx_data(0x406028, 4)
mmctx_data(0x4064a8, 2)
mmctx_data(0x4064b4, 2)
mmctx_data(0x407804, 1)
mmctx_data(0x40780c, 6)
mmctx_data(0x4078bc, 1)
mmctx_data(0x408000, 7)
mmctx_data(0x408064, 1)
mmctx_data(0x408800, 3)
mmctx_data(0x408900, 4)
mmctx_data(0x408980, 1)
nvc0_hub_mmio_tail:
mmctx_data(0x4064c0, 2)
nvc1_hub_mmio_tail:
.align 256
chan_data:
chan_mmio_count: .b32 0
chan_mmio_address: .b32 0
.align 256
xfer_data: .b32 0
.section nvc0_grhub_code
bra init
define(`include_code')
include(`nvc0_graph.fuc')
// reports an exception to the host
//
// In: $r15 error code (see nvc0_graph.fuc)
//
error:
push $r14
mov $r14 0x814
shl b32 $r14 6
iowr I[$r14 + 0x000] $r15 // CC_SCRATCH[5] = error code
mov $r14 0xc1c
shl b32 $r14 6
mov $r15 1
iowr I[$r14 + 0x000] $r15 // INTR_UP_SET
pop $r14
ret
// HUB fuc initialisation, executed by triggering ucode start, will
// fall through to main loop after completion.
//
// Input:
// CC_SCRATCH[0]: chipset (PMC_BOOT_0 read returns 0x0bad0bad... sigh)
//
// Output:
// CC_SCRATCH[0]:
// 31:31: set to signal completion
// CC_SCRATCH[1]:
// 31:0: total PGRAPH context size
//
init:
clear b32 $r0
mov $sp $r0
mov $xdbase $r0
// enable fifo access
mov $r1 0x1200
mov $r2 2
iowr I[$r1 + 0x000] $r2 // FIFO_ENABLE
// setup i0 handler, and route all interrupts to it
mov $r1 ih
mov $iv0 $r1
mov $r1 0x400
iowr I[$r1 + 0x300] $r0 // INTR_DISPATCH
// route HUB_CHANNEL_SWITCH to fuc interrupt 8
mov $r3 0x404
shl b32 $r3 6
mov $r2 0x2003 // { HUB_CHANNEL_SWITCH, ZERO } -> intr 8
iowr I[$r3 + 0x000] $r2
// not sure what these are, route them because NVIDIA does, and
// the IRQ handler will signal the host if we ever get one.. we
// may find out if/why we need to handle these if so..
//
mov $r2 0x2004
iowr I[$r3 + 0x004] $r2 // { 0x04, ZERO } -> intr 9
mov $r2 0x200b
iowr I[$r3 + 0x008] $r2 // { 0x0b, ZERO } -> intr 10
mov $r2 0x200c
iowr I[$r3 + 0x01c] $r2 // { 0x0c, ZERO } -> intr 15
// enable all INTR_UP interrupts
mov $r2 0xc24
shl b32 $r2 6
not b32 $r3 $r0
iowr I[$r2] $r3
// enable fifo, ctxsw, 9, 10, 15 interrupts
mov $r2 -0x78fc // 0x8704
sethi $r2 0
iowr I[$r1 + 0x000] $r2 // INTR_EN_SET
// fifo level triggered, rest edge
sub b32 $r1 0x100
mov $r2 4
iowr I[$r1] $r2
// enable interrupts
bset $flags ie0
// fetch enabled GPC/ROP counts
mov $r14 -0x69fc // 0x409604
sethi $r14 0x400000
call nv_rd32
extr $r1 $r15 16:20
st b32 D[$r0 + rop_count] $r1
and $r15 0x1f
st b32 D[$r0 + gpc_count] $r15
// set BAR_REQMASK to GPC mask
mov $r1 1
shl b32 $r1 $r15
sub b32 $r1 1
mov $r2 0x40c
shl b32 $r2 6
iowr I[$r2 + 0x000] $r1
iowr I[$r2 + 0x100] $r1
// find context data for this chipset
mov $r2 0x800
shl b32 $r2 6
iord $r2 I[$r2 + 0x000] // CC_SCRATCH[0]
mov $r15 chipsets - 8
init_find_chipset:
add b32 $r15 8
ld b32 $r3 D[$r15 + 0x00]
cmpu b32 $r3 $r2
bra e init_context
cmpu b32 $r3 0
bra ne init_find_chipset
// unknown chipset
ret
// context size calculation, reserve first 256 bytes for use by fuc
init_context:
mov $r1 256
// calculate size of mmio context data
ld b16 $r14 D[$r15 + 4]
ld b16 $r15 D[$r15 + 6]
sethi $r14 0
st b32 D[$r0 + hub_mmio_list_head] $r14
st b32 D[$r0 + hub_mmio_list_tail] $r15
call mmctx_size
// set mmctx base addresses now so we don't have to do it later,
// they don't (currently) ever change
mov $r3 0x700
shl b32 $r3 6
shr b32 $r4 $r1 8
iowr I[$r3 + 0x000] $r4 // MMCTX_SAVE_SWBASE
iowr I[$r3 + 0x100] $r4 // MMCTX_LOAD_SWBASE
add b32 $r3 0x1300
add b32 $r1 $r15
shr b32 $r15 2
iowr I[$r3 + 0x000] $r15 // MMCTX_LOAD_COUNT, wtf for?!?
// strands, base offset needs to be aligned to 256 bytes
shr b32 $r1 8
add b32 $r1 1
shl b32 $r1 8
mov b32 $r15 $r1
call strand_ctx_init
add b32 $r1 $r15
// initialise each GPC in sequence by passing in the offset of its
// context data in GPCn_CC_SCRATCH[1], and starting its FUC (which
// has previously been uploaded by the host) running.
//
// the GPC fuc init sequence will set GPCn_CC_SCRATCH[0] bit 31
// when it has completed, and return the size of its context data
// in GPCn_CC_SCRATCH[1]
//
ld b32 $r3 D[$r0 + gpc_count]
mov $r4 0x2000
sethi $r4 0x500000
init_gpc:
// setup, and start GPC ucode running
add b32 $r14 $r4 0x804
mov b32 $r15 $r1
call nv_wr32 // CC_SCRATCH[1] = ctx offset
add b32 $r14 $r4 0x800
mov b32 $r15 $r2
call nv_wr32 // CC_SCRATCH[0] = chipset
add b32 $r14 $r4 0x10c
clear b32 $r15
call nv_wr32
add b32 $r14 $r4 0x104
call nv_wr32 // ENTRY
add b32 $r14 $r4 0x100
mov $r15 2 // CTRL_START_TRIGGER
call nv_wr32 // CTRL
// wait for it to complete, and adjust context size
add b32 $r14 $r4 0x800
init_gpc_wait:
call nv_rd32
xbit $r15 $r15 31
bra e init_gpc_wait
add b32 $r14 $r4 0x804
call nv_rd32
add b32 $r1 $r15
// next!
add b32 $r4 0x8000
sub b32 $r3 1
bra ne init_gpc
// save context size, and tell host we're ready
mov $r2 0x800
shl b32 $r2 6
iowr I[$r2 + 0x100] $r1 // CC_SCRATCH[1] = context size
add b32 $r2 0x800
clear b32 $r1
bset $r1 31
iowr I[$r2 + 0x000] $r1 // CC_SCRATCH[0] |= 0x80000000
// Main program loop, very simple, sleeps until woken up by the interrupt
// handler, pulls a command from the queue and executes its handler
//
main:
// sleep until we have something to do
bset $flags $p0
sleep $p0
mov $r13 cmd_queue
call queue_get
bra $p1 main
// context switch, requested by GPU?
cmpu b32 $r14 0x4001
bra ne main_not_ctx_switch
trace_set(T_AUTO)
mov $r1 0xb00
shl b32 $r1 6
iord $r2 I[$r1 + 0x100] // CHAN_NEXT
iord $r1 I[$r1 + 0x000] // CHAN_CUR
xbit $r3 $r1 31
bra e chsw_no_prev
xbit $r3 $r2 31
bra e chsw_prev_no_next
push $r2
mov b32 $r2 $r1
trace_set(T_SAVE)
bclr $flags $p1
bset $flags $p2
call ctx_xfer
trace_clr(T_SAVE);
pop $r2
trace_set(T_LOAD);
bset $flags $p1
call ctx_xfer
trace_clr(T_LOAD);
bra chsw_done
chsw_prev_no_next:
push $r2
mov b32 $r2 $r1
bclr $flags $p1
bclr $flags $p2
call ctx_xfer
pop $r2
mov $r1 0xb00
shl b32 $r1 6
iowr I[$r1] $r2
bra chsw_done
chsw_no_prev:
xbit $r3 $r2 31
bra e chsw_done
bset $flags $p1
bclr $flags $p2
call ctx_xfer
// ack the context switch request
chsw_done:
mov $r1 0xb0c
shl b32 $r1 6
mov $r2 1
iowr I[$r1 + 0x000] $r2 // 0x409b0c
trace_clr(T_AUTO)
bra main
// request to set current channel? (*not* a context switch)
main_not_ctx_switch:
cmpu b32 $r14 0x0001
bra ne main_not_ctx_chan
mov b32 $r2 $r15
call ctx_chan
bra main_done
// request to store current channel context?
main_not_ctx_chan:
cmpu b32 $r14 0x0002
bra ne main_not_ctx_save
trace_set(T_SAVE)
bclr $flags $p1
bclr $flags $p2
call ctx_xfer
trace_clr(T_SAVE)
bra main_done
main_not_ctx_save:
shl b32 $r15 $r14 16
or $r15 E_BAD_COMMAND
call error
bra main
main_done:
mov $r1 0x820
shl b32 $r1 6
clear b32 $r2
bset $r2 31
iowr I[$r1 + 0x000] $r2 // CC_SCRATCH[0] |= 0x80000000
bra main
// interrupt handler
ih:
push $r8
mov $r8 $flags
push $r8
push $r9
push $r10
push $r11
push $r13
push $r14
push $r15
// incoming fifo command?
iord $r10 I[$r0 + 0x200] // INTR
and $r11 $r10 0x00000004
bra e ih_no_fifo
// queue incoming fifo command for later processing
mov $r11 0x1900
mov $r13 cmd_queue
iord $r14 I[$r11 + 0x100] // FIFO_CMD
iord $r15 I[$r11 + 0x000] // FIFO_DATA
call queue_put
add b32 $r11 0x400
mov $r14 1
iowr I[$r11 + 0x000] $r14 // FIFO_ACK
// context switch request?
ih_no_fifo:
and $r11 $r10 0x00000100
bra e ih_no_ctxsw
// enqueue a context switch for later processing
mov $r13 cmd_queue
mov $r14 0x4001
call queue_put
// anything we didn't handle, bring it to the host's attention
ih_no_ctxsw:
mov $r11 0x104
not b32 $r11
and $r11 $r10 $r11
bra e ih_no_other
mov $r10 0xc1c
shl b32 $r10 6
iowr I[$r10] $r11 // INTR_UP_SET
// ack, and wake up main()
ih_no_other:
iowr I[$r0 + 0x100] $r10 // INTR_ACK
pop $r15
pop $r14
pop $r13
pop $r11
pop $r10
pop $r9
pop $r8
mov $flags $r8
pop $r8
bclr $flags $p0
iret
// Not real sure, but, MEM_CMD 7 will hang forever if this isn't done
ctx_4160s:
mov $r14 0x4160
sethi $r14 0x400000
mov $r15 1
call nv_wr32
ctx_4160s_wait:
call nv_rd32
xbit $r15 $r15 4
bra e ctx_4160s_wait
ret
// Without clearing again at end of xfer, some things cause PGRAPH
// to hang with STATUS=0x00000007 until it's cleared.. fbcon can
// still function with it set however...
ctx_4160c:
mov $r14 0x4160
sethi $r14 0x400000
clear b32 $r15
call nv_wr32
ret
// Again, not real sure
//
// In: $r15 value to set 0x404170 to
//
ctx_4170s:
mov $r14 0x4170
sethi $r14 0x400000
or $r15 0x10
call nv_wr32
ret
// Waits for a ctx_4170s() call to complete
//
ctx_4170w:
mov $r14 0x4170
sethi $r14 0x400000
call nv_rd32
and $r15 0x10
bra ne ctx_4170w
ret
// Disables various things, waits a bit, and re-enables them..
//
// Not sure how exactly this helps, perhaps "ENABLE" is not such a
// good description for the bits we turn off? Anyways, without this,
// funny things happen.
//
ctx_redswitch:
mov $r14 0x614
shl b32 $r14 6
mov $r15 0x270
iowr I[$r14] $r15 // HUB_RED_SWITCH = ENABLE_GPC, POWER_ALL
mov $r15 8
ctx_redswitch_delay:
sub b32 $r15 1
bra ne ctx_redswitch_delay
mov $r15 0x770
iowr I[$r14] $r15 // HUB_RED_SWITCH = ENABLE_ALL, POWER_ALL
ret
// Not a clue what this is for, except that unless the value is 0x10, the
// strand context is saved (and presumably restored) incorrectly..
//
// In: $r15 value to set to (0x00/0x10 are used)
//
ctx_86c:
mov $r14 0x86c
shl b32 $r14 6
iowr I[$r14] $r15 // HUB(0x86c) = val
mov $r14 -0x75ec
sethi $r14 0x400000
call nv_wr32 // ROP(0xa14) = val
mov $r14 -0x5794
sethi $r14 0x410000
call nv_wr32 // GPC(0x86c) = val
ret
// ctx_load - load's a channel's ctxctl data, and selects its vm
//
// In: $r2 channel address
//
ctx_load:
trace_set(T_CHAN)
// switch to channel, somewhat magic in parts..
mov $r10 12 // DONE_UNK12
call wait_donez
mov $r1 0xa24
shl b32 $r1 6
iowr I[$r1 + 0x000] $r0 // 0x409a24
mov $r3 0xb00
shl b32 $r3 6
iowr I[$r3 + 0x100] $r2 // CHAN_NEXT
mov $r1 0xa0c
shl b32 $r1 6
mov $r4 7
iowr I[$r1 + 0x000] $r2 // MEM_CHAN
iowr I[$r1 + 0x100] $r4 // MEM_CMD
ctx_chan_wait_0:
iord $r4 I[$r1 + 0x100]
and $r4 0x1f
bra ne ctx_chan_wait_0
iowr I[$r3 + 0x000] $r2 // CHAN_CUR
// load channel header, fetch PGRAPH context pointer
mov $xtargets $r0
bclr $r2 31
shl b32 $r2 4
add b32 $r2 2
trace_set(T_LCHAN)
mov $r1 0xa04
shl b32 $r1 6
iowr I[$r1 + 0x000] $r2 // MEM_BASE
mov $r1 0xa20
shl b32 $r1 6
mov $r2 0x0002
sethi $r2 0x80000000
iowr I[$r1 + 0x000] $r2 // MEM_TARGET = vram
mov $r1 0x10 // chan + 0x0210
mov $r2 xfer_data
sethi $r2 0x00020000 // 16 bytes
xdld $r1 $r2
xdwait
trace_clr(T_LCHAN)
// update current context
ld b32 $r1 D[$r0 + xfer_data + 4]
shl b32 $r1 24
ld b32 $r2 D[$r0 + xfer_data + 0]
shr b32 $r2 8
or $r1 $r2
st b32 D[$r0 + ctx_current] $r1
// set transfer base to start of context, and fetch context header
trace_set(T_LCTXH)
mov $r2 0xa04
shl b32 $r2 6
iowr I[$r2 + 0x000] $r1 // MEM_BASE
mov $r2 1
mov $r1 0xa20
shl b32 $r1 6
iowr I[$r1 + 0x000] $r2 // MEM_TARGET = vm
mov $r1 chan_data
sethi $r1 0x00060000 // 256 bytes
xdld $r0 $r1
xdwait
trace_clr(T_LCTXH)
trace_clr(T_CHAN)
ret
// ctx_chan - handler for HUB_SET_CHAN command, will set a channel as
// the active channel for ctxctl, but not actually transfer
// any context data. intended for use only during initial
// context construction.
//
// In: $r2 channel address
//
ctx_chan:
call ctx_4160s
call ctx_load
mov $r10 12 // DONE_UNK12
call wait_donez
mov $r1 0xa10
shl b32 $r1 6
mov $r2 5
iowr I[$r1 + 0x000] $r2 // MEM_CMD = 5 (???)
ctx_chan_wait:
iord $r2 I[$r1 + 0x000]
or $r2 $r2
bra ne ctx_chan_wait
call ctx_4160c
ret
// Execute per-context state overrides list
//
// Only executed on the first load of a channel. Might want to look into
// removing this and having the host directly modify the channel's context
// to change this state... The nouveau DRM already builds this list as
// it's definitely needed for NVIDIA's, so we may as well use it for now
//
// Input: $r1 mmio list length
//
ctx_mmio_exec:
// set transfer base to be the mmio list
ld b32 $r3 D[$r0 + chan_mmio_address]
mov $r2 0xa04
shl b32 $r2 6
iowr I[$r2 + 0x000] $r3 // MEM_BASE
clear b32 $r3
ctx_mmio_loop:
// fetch next 256 bytes of mmio list if necessary
and $r4 $r3 0xff
bra ne ctx_mmio_pull
mov $r5 xfer_data
sethi $r5 0x00060000 // 256 bytes
xdld $r3 $r5
xdwait
// execute a single list entry
ctx_mmio_pull:
ld b32 $r14 D[$r4 + xfer_data + 0x00]
ld b32 $r15 D[$r4 + xfer_data + 0x04]
call nv_wr32
// next!
add b32 $r3 8
sub b32 $r1 1
bra ne ctx_mmio_loop
// set transfer base back to the current context
ctx_mmio_done:
ld b32 $r3 D[$r0 + ctx_current]
iowr I[$r2 + 0x000] $r3 // MEM_BASE
// disable the mmio list now, we don't need/want to execute it again
st b32 D[$r0 + chan_mmio_count] $r0
mov $r1 chan_data
sethi $r1 0x00060000 // 256 bytes
xdst $r0 $r1
xdwait
ret
// Transfer HUB context data between GPU and storage area
//
// In: $r2 channel address
// $p1 clear on save, set on load
// $p2 set if opposite direction done/will be done, so:
// on save it means: "a load will follow this save"
// on load it means: "a save preceeded this load"
//
ctx_xfer:
bra not $p1 ctx_xfer_pre
bra $p2 ctx_xfer_pre_load
ctx_xfer_pre:
mov $r15 0x10
call ctx_86c
call ctx_4160s
bra not $p1 ctx_xfer_exec
ctx_xfer_pre_load:
mov $r15 2
call ctx_4170s
call ctx_4170w
call ctx_redswitch
clear b32 $r15
call ctx_4170s
call ctx_load
// fetch context pointer, and initiate xfer on all GPCs
ctx_xfer_exec:
ld b32 $r1 D[$r0 + ctx_current]
mov $r2 0x414
shl b32 $r2 6
iowr I[$r2 + 0x000] $r0 // BAR_STATUS = reset
mov $r14 -0x5b00
sethi $r14 0x410000
mov b32 $r15 $r1
call nv_wr32 // GPC_BCAST_WRCMD_DATA = ctx pointer
add b32 $r14 4
xbit $r15 $flags $p1
xbit $r2 $flags $p2
shl b32 $r2 1
or $r15 $r2
call nv_wr32 // GPC_BCAST_WRCMD_CMD = GPC_XFER(type)
// strands
mov $r1 0x4afc
sethi $r1 0x20000
mov $r2 0xc
iowr I[$r1] $r2 // STRAND_CMD(0x3f) = 0x0c
call strand_wait
mov $r2 0x47fc
sethi $r2 0x20000
iowr I[$r2] $r0 // STRAND_FIRST_GENE(0x3f) = 0x00
xbit $r2 $flags $p1
add b32 $r2 3
iowr I[$r1] $r2 // STRAND_CMD(0x3f) = 0x03/0x04 (SAVE/LOAD)
// mmio context
xbit $r10 $flags $p1 // direction
or $r10 6 // first, last
mov $r11 0 // base = 0
ld b32 $r12 D[$r0 + hub_mmio_list_head]
ld b32 $r13 D[$r0 + hub_mmio_list_tail]
mov $r14 0 // not multi
call mmctx_xfer
// wait for GPCs to all complete
mov $r10 8 // DONE_BAR
call wait_doneo
// wait for strand xfer to complete
call strand_wait
// post-op
bra $p1 ctx_xfer_post
mov $r10 12 // DONE_UNK12
call wait_donez
mov $r1 0xa10
shl b32 $r1 6
mov $r2 5
iowr I[$r1] $r2 // MEM_CMD
ctx_xfer_post_save_wait:
iord $r2 I[$r1]
or $r2 $r2
bra ne ctx_xfer_post_save_wait
bra $p2 ctx_xfer_done
ctx_xfer_post:
mov $r15 2
call ctx_4170s
clear b32 $r15
call ctx_86c
call strand_post
call ctx_4170w
clear b32 $r15
call ctx_4170s
bra not $p1 ctx_xfer_no_post_mmio
ld b32 $r1 D[$r0 + chan_mmio_count]
or $r1 $r1
bra e ctx_xfer_no_post_mmio
call ctx_mmio_exec
ctx_xfer_no_post_mmio:
call ctx_4160c
ctx_xfer_done:
ret
.align 256