drivers/gpu/drm/nouveau/nvc0_graph.fuc - maze/linux - Git at Google

 /* fuc microcode util functions for nvc0 PGRAPH
  *
  * 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
  */

 define(`mmctx_data', `.b32 eval((($2 - 1) << 26) | $1)')
 define(`queue_init', `.skip eval((2 * 4) + ((8 * 4) * 2))')

 ifdef(`include_code', `
 // Error codes
 define(`E_BAD_COMMAND', 0x01)
 define(`E_CMD_OVERFLOW', 0x02)

 // Util macros to help with debugging ucode hangs etc
 define(`T_WAIT', 0)
 define(`T_MMCTX', 1)
 define(`T_STRWAIT', 2)
 define(`T_STRINIT', 3)
 define(`T_AUTO', 4)
 define(`T_CHAN', 5)
 define(`T_LOAD', 6)
 define(`T_SAVE', 7)
 define(`T_LCHAN', 8)
 define(`T_LCTXH', 9)

 define(`trace_set', `
 	mov $r8 0x83c
 	shl b32 $r8 6
 	clear b32 $r9
 	bset $r9 $1
 	iowr I[$r8 + 0x000] $r9		// CC_SCRATCH[7]
 ')

 define(`trace_clr', `
 	mov $r8 0x85c
 	shl b32 $r8 6
 	clear b32 $r9
 	bset $r9 $1
 	iowr I[$r8 + 0x000] $r9		// CC_SCRATCH[7]
 ')

 // queue_put - add request to queue
 //
 // In : $r13 queue pointer
 //	$r14 command
 //	$r15 data
 //
 queue_put:
 	// make sure we have space..
 	ld b32 $r8 D[$r13 + 0x0]	// GET
 	ld b32 $r9 D[$r13 + 0x4]	// PUT
 	xor $r8 8
 	cmpu b32 $r8 $r9
 	bra ne queue_put_next
 		mov $r15 E_CMD_OVERFLOW
 		call error
 		ret

 	// store cmd/data on queue
 	queue_put_next:
 	and $r8 $r9 7
 	shl b32 $r8 3
 	add b32 $r8 $r13
 	add b32 $r8 8
 	st b32 D[$r8 + 0x0] $r14
 	st b32 D[$r8 + 0x4] $r15

 	// update PUT
 	add b32 $r9 1
 	and $r9 0xf
 	st b32 D[$r13 + 0x4] $r9
 	ret

 // queue_get - fetch request from queue
 //
 // In : $r13 queue pointer
 //
 // Out:	$p1  clear on success (data available)
 //	$r14 command
 // 	$r15 data
 //
 queue_get:
 	bset $flags $p1
 	ld b32 $r8 D[$r13 + 0x0]	// GET
 	ld b32 $r9 D[$r13 + 0x4]	// PUT
 	cmpu b32 $r8 $r9
 	bra e queue_get_done
 		// fetch first cmd/data pair
 		and $r9 $r8 7
 		shl b32 $r9 3
 		add b32 $r9 $r13
 		add b32 $r9 8
 		ld b32 $r14 D[$r9 + 0x0]
 		ld b32 $r15 D[$r9 + 0x4]

 		// update GET
 		add b32 $r8 1
 		and $r8 0xf
 		st b32 D[$r13 + 0x0] $r8
 		bclr $flags $p1
 queue_get_done:
 	ret

 // nv_rd32 - read 32-bit value from nv register
 //
 // In : $r14 register
 // Out: $r15 value
 //
 nv_rd32:
 	mov $r11 0x728
 	shl b32 $r11 6
 	mov b32 $r12 $r14
 	bset $r12 31			// MMIO_CTRL_PENDING
 	iowr I[$r11 + 0x000] $r12	// MMIO_CTRL
 	nv_rd32_wait:
 		iord $r12 I[$r11 + 0x000]
 		xbit $r12 $r12 31
 		bra ne nv_rd32_wait
 	mov $r10 6			// DONE_MMIO_RD
 	call wait_doneo
 	iord $r15 I[$r11 + 0x100]	// MMIO_RDVAL
 	ret

 // nv_wr32 - write 32-bit value to nv register
 //
 // In : $r14 register
 //      $r15 value
 //
 nv_wr32:
 	mov $r11 0x728
 	shl b32 $r11 6
 	iowr I[$r11 + 0x200] $r15	// MMIO_WRVAL
 	mov b32 $r12 $r14
 	bset $r12 31			// MMIO_CTRL_PENDING
 	bset $r12 30			// MMIO_CTRL_WRITE
 	iowr I[$r11 + 0x000] $r12	// MMIO_CTRL
 	nv_wr32_wait:
 		iord $r12 I[$r11 + 0x000]
 		xbit $r12 $r12 31
 		bra ne nv_wr32_wait
 	ret

 // (re)set watchdog timer
 //
 // In : $r15 timeout
 //
 watchdog_reset:
 	mov $r8 0x430
 	shl b32 $r8 6
 	bset $r15 31
 	iowr I[$r8 + 0x000] $r15
 	ret

 // clear watchdog timer
 watchdog_clear:
 	mov $r8 0x430
 	shl b32 $r8 6
 	iowr I[$r8 + 0x000] $r0
 	ret

 // wait_done{z,o} - wait on FUC_DONE bit to become clear/set
 //
 // In : $r10 bit to wait on
 //
 define(`wait_done', `
 $1:
 	trace_set(T_WAIT);
 	mov $r8 0x818
 	shl b32 $r8 6
 	iowr I[$r8 + 0x000] $r10	// CC_SCRATCH[6] = wait bit
 	wait_done_$1:
 		mov $r8 0x400
 		shl b32 $r8 6
 		iord $r8 I[$r8 + 0x000]	// DONE
 		xbit $r8 $r8 $r10
 		bra $2 wait_done_$1
 	trace_clr(T_WAIT)
 	ret
 ')
 wait_done(wait_donez, ne)
 wait_done(wait_doneo, e)

 // mmctx_size - determine size of a mmio list transfer
 //
 // In : $r14 mmio list head
 //      $r15 mmio list tail
 // Out: $r15 transfer size (in bytes)
 //
 mmctx_size:
 	clear b32 $r9
 	nv_mmctx_size_loop:
 		ld b32 $r8 D[$r14]
 		shr b32 $r8 26
 		add b32 $r8 1
 		shl b32 $r8 2
 		add b32 $r9 $r8
 		add b32 $r14 4
 		cmpu b32 $r14 $r15
 		bra ne nv_mmctx_size_loop
 	mov b32 $r15 $r9
 	ret

 // mmctx_xfer - execute a list of mmio transfers
 //
 // In : $r10 flags
 //		bit 0: direction (0 = save, 1 = load)
 //		bit 1: set if first transfer
 //		bit 2: set if last transfer
 //	$r11 base
 //	$r12 mmio list head
 //	$r13 mmio list tail
 //	$r14 multi_stride
 //	$r15 multi_mask
 //
 mmctx_xfer:
 	trace_set(T_MMCTX)
 	mov $r8 0x710
 	shl b32 $r8 6
 	clear b32 $r9
 	or $r11 $r11
 	bra e mmctx_base_disabled
 		iowr I[$r8 + 0x000] $r11	// MMCTX_BASE
 		bset $r9 0			// BASE_EN
 	mmctx_base_disabled:
 	or $r14 $r14
 	bra e mmctx_multi_disabled
 		iowr I[$r8 + 0x200] $r14 	// MMCTX_MULTI_STRIDE
 		iowr I[$r8 + 0x300] $r15 	// MMCTX_MULTI_MASK
 		bset $r9 1			// MULTI_EN
 	mmctx_multi_disabled:
 	add b32 $r8 0x100

 	xbit $r11 $r10 0
 	shl b32 $r11 16			// DIR
 	bset $r11 12			// QLIMIT = 0x10
 	xbit $r14 $r10 1
 	shl b32 $r14 17
 	or $r11 $r14			// START_TRIGGER
 	iowr I[$r8 + 0x000] $r11	// MMCTX_CTRL

 	// loop over the mmio list, and send requests to the hw
 	mmctx_exec_loop:
 		// wait for space in mmctx queue
 		mmctx_wait_free:
 			iord $r14 I[$r8 + 0x000] // MMCTX_CTRL
 			and $r14 0x1f
 			bra e mmctx_wait_free

 		// queue up an entry
 		ld b32 $r14 D[$r12]
 		or $r14 $r9
 		iowr I[$r8 + 0x300] $r14
 		add b32 $r12 4
 		cmpu b32 $r12 $r13
 		bra ne mmctx_exec_loop

 	xbit $r11 $r10 2
 	bra ne mmctx_stop
 		// wait for queue to empty
 		mmctx_fini_wait:
 			iord $r11 I[$r8 + 0x000]	// MMCTX_CTRL
 			and $r11 0x1f
 			cmpu b32 $r11 0x10
 			bra ne mmctx_fini_wait
 		mov $r10 2				// DONE_MMCTX
 		call wait_donez
 		bra mmctx_done
 	mmctx_stop:
 		xbit $r11 $r10 0
 		shl b32 $r11 16			// DIR
 		bset $r11 12			// QLIMIT = 0x10
 		bset $r11 18			// STOP_TRIGGER
 		iowr I[$r8 + 0x000] $r11	// MMCTX_CTRL
 		mmctx_stop_wait:
 			// wait for STOP_TRIGGER to clear
 			iord $r11 I[$r8 + 0x000] // MMCTX_CTRL
 			xbit $r11 $r11 18
 			bra ne mmctx_stop_wait
 	mmctx_done:
 	trace_clr(T_MMCTX)
 	ret

 // Wait for DONE_STRAND
 //
 strand_wait:
 	push $r10
 	mov $r10 2
 	call wait_donez
 	pop $r10
 	ret

 // unknown - call before issuing strand commands
 //
 strand_pre:
 	mov $r8 0x4afc
 	sethi $r8 0x20000
 	mov $r9 0xc
 	iowr I[$r8] $r9
 	call strand_wait
 	ret

 // unknown - call after issuing strand commands
 //
 strand_post:
 	mov $r8 0x4afc
 	sethi $r8 0x20000
 	mov $r9 0xd
 	iowr I[$r8] $r9
 	call strand_wait
 	ret

 // Selects strand set?!
 //
 // In: $r14 id
 //
 strand_set:
 	mov $r10 0x4ffc
 	sethi $r10 0x20000
 	sub b32 $r11 $r10 0x500
 	mov $r12 0xf
 	iowr I[$r10 + 0x000] $r12		// 0x93c = 0xf
 	mov $r12 0xb
 	iowr I[$r11 + 0x000] $r12		// 0x928 = 0xb
 	call strand_wait
 	iowr I[$r10 + 0x000] $r14		// 0x93c = <id>
 	mov $r12 0xa
 	iowr I[$r11 + 0x000] $r12		// 0x928 = 0xa
 	call strand_wait
 	ret

 // Initialise strand context data
 //
 // In : $r15 context base
 // Out: $r15 context size (in bytes)
 //
 // Strandset(?) 3 hardcoded currently
 //
 strand_ctx_init:
 	trace_set(T_STRINIT)
 	call strand_pre
 	mov $r14 3
 	call strand_set
 	mov $r10 0x46fc
 	sethi $r10 0x20000
 	add b32 $r11 $r10 0x400
 	iowr I[$r10 + 0x100] $r0	// STRAND_FIRST_GENE = 0
 	mov $r12 1
 	iowr I[$r11 + 0x000] $r12	// STRAND_CMD = LATCH_FIRST_GENE
 	call strand_wait
 	sub b32 $r12 $r0 1
 	iowr I[$r10 + 0x000] $r12	// STRAND_GENE_CNT = 0xffffffff
 	mov $r12 2
 	iowr I[$r11 + 0x000] $r12	// STRAND_CMD = LATCH_GENE_CNT
 	call strand_wait
 	call strand_post

 	// read the size of each strand, poke the context offset of
 	// each into STRAND_{SAVE,LOAD}_SWBASE now, no need to worry
 	// about it later then.
 	mov $r8 0x880
 	shl b32 $r8 6
 	iord $r9 I[$r8 + 0x000]		// STRANDS
 	add b32 $r8 0x2200
 	shr b32 $r14 $r15 8
 	ctx_init_strand_loop:
 		iowr I[$r8 + 0x000] $r14	// STRAND_SAVE_SWBASE
 		iowr I[$r8 + 0x100] $r14	// STRAND_LOAD_SWBASE
 		iord $r10 I[$r8 + 0x200]	// STRAND_SIZE
 		shr b32 $r10 6
 		add b32 $r10 1
 		add b32 $r14 $r10
 		add b32 $r8 4
 		sub b32 $r9 1
 		bra ne ctx_init_strand_loop

 	shl b32 $r14 8
 	sub b32 $r15 $r14 $r15
 	trace_clr(T_STRINIT)
 	ret
 ')
	/* fuc microcode util functions for nvc0 PGRAPH
	*
	* 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
	*/

	define(`mmctx_data', `.b32 eval((($2 - 1) << 26) \| $1)')
	define(`queue_init', `.skip eval((2 * 4) + ((8 * 4) * 2))')

	ifdef(`include_code', `
	// Error codes
	define(`E_BAD_COMMAND', 0x01)
	define(`E_CMD_OVERFLOW', 0x02)

	// Util macros to help with debugging ucode hangs etc
	define(`T_WAIT', 0)
	define(`T_MMCTX', 1)
	define(`T_STRWAIT', 2)
	define(`T_STRINIT', 3)
	define(`T_AUTO', 4)
	define(`T_CHAN', 5)
	define(`T_LOAD', 6)
	define(`T_SAVE', 7)
	define(`T_LCHAN', 8)
	define(`T_LCTXH', 9)

	define(`trace_set', `
	mov $r8 0x83c
	shl b32 $r8 6
	clear b32 $r9
	bset $r9 $1
	iowr I[$r8 + 0x000] $r9 // CC_SCRATCH[7]
	')

	define(`trace_clr', `
	mov $r8 0x85c
	shl b32 $r8 6
	clear b32 $r9
	bset $r9 $1
	iowr I[$r8 + 0x000] $r9 // CC_SCRATCH[7]
	')

	// queue_put - add request to queue
	//
	// In : $r13 queue pointer
	// $r14 command
	// $r15 data
	//
	queue_put:
	// make sure we have space..
	ld b32 $r8 D[$r13 + 0x0] // GET
	ld b32 $r9 D[$r13 + 0x4] // PUT
	xor $r8 8
	cmpu b32 $r8 $r9
	bra ne queue_put_next
	mov $r15 E_CMD_OVERFLOW
	call error
	ret

	// store cmd/data on queue
	queue_put_next:
	and $r8 $r9 7
	shl b32 $r8 3
	add b32 $r8 $r13
	add b32 $r8 8
	st b32 D[$r8 + 0x0] $r14
	st b32 D[$r8 + 0x4] $r15

	// update PUT
	add b32 $r9 1
	and $r9 0xf
	st b32 D[$r13 + 0x4] $r9
	ret

	// queue_get - fetch request from queue
	//
	// In : $r13 queue pointer
	//
	// Out: $p1 clear on success (data available)
	// $r14 command
	// $r15 data
	//
	queue_get:
	bset $flags $p1
	ld b32 $r8 D[$r13 + 0x0] // GET
	ld b32 $r9 D[$r13 + 0x4] // PUT
	cmpu b32 $r8 $r9
	bra e queue_get_done
	// fetch first cmd/data pair
	and $r9 $r8 7
	shl b32 $r9 3
	add b32 $r9 $r13
	add b32 $r9 8
	ld b32 $r14 D[$r9 + 0x0]
	ld b32 $r15 D[$r9 + 0x4]

	// update GET
	add b32 $r8 1
	and $r8 0xf
	st b32 D[$r13 + 0x0] $r8
	bclr $flags $p1
	queue_get_done:
	ret

	// nv_rd32 - read 32-bit value from nv register
	//
	// In : $r14 register
	// Out: $r15 value
	//
	nv_rd32:
	mov $r11 0x728
	shl b32 $r11 6
	mov b32 $r12 $r14
	bset $r12 31 // MMIO_CTRL_PENDING
	iowr I[$r11 + 0x000] $r12 // MMIO_CTRL
	nv_rd32_wait:
	iord $r12 I[$r11 + 0x000]
	xbit $r12 $r12 31
	bra ne nv_rd32_wait
	mov $r10 6 // DONE_MMIO_RD
	call wait_doneo
	iord $r15 I[$r11 + 0x100] // MMIO_RDVAL
	ret

	// nv_wr32 - write 32-bit value to nv register
	//
	// In : $r14 register
	// $r15 value
	//
	nv_wr32:
	mov $r11 0x728
	shl b32 $r11 6
	iowr I[$r11 + 0x200] $r15 // MMIO_WRVAL
	mov b32 $r12 $r14
	bset $r12 31 // MMIO_CTRL_PENDING
	bset $r12 30 // MMIO_CTRL_WRITE
	iowr I[$r11 + 0x000] $r12 // MMIO_CTRL
	nv_wr32_wait:
	iord $r12 I[$r11 + 0x000]
	xbit $r12 $r12 31
	bra ne nv_wr32_wait
	ret

	// (re)set watchdog timer
	//
	// In : $r15 timeout
	//
	watchdog_reset:
	mov $r8 0x430
	shl b32 $r8 6
	bset $r15 31
	iowr I[$r8 + 0x000] $r15
	ret

	// clear watchdog timer
	watchdog_clear:
	mov $r8 0x430
	shl b32 $r8 6
	iowr I[$r8 + 0x000] $r0
	ret

	// wait_done{z,o} - wait on FUC_DONE bit to become clear/set
	//
	// In : $r10 bit to wait on
	//
	define(`wait_done', `
	$1:
	trace_set(T_WAIT);
	mov $r8 0x818
	shl b32 $r8 6
	iowr I[$r8 + 0x000] $r10 // CC_SCRATCH[6] = wait bit
	wait_done_$1:
	mov $r8 0x400
	shl b32 $r8 6
	iord $r8 I[$r8 + 0x000] // DONE
	xbit $r8 $r8 $r10
	bra $2 wait_done_$1
	trace_clr(T_WAIT)
	ret
	')
	wait_done(wait_donez, ne)
	wait_done(wait_doneo, e)

	// mmctx_size - determine size of a mmio list transfer
	//
	// In : $r14 mmio list head
	// $r15 mmio list tail
	// Out: $r15 transfer size (in bytes)
	//
	mmctx_size:
	clear b32 $r9
	nv_mmctx_size_loop:
	ld b32 $r8 D[$r14]
	shr b32 $r8 26
	add b32 $r8 1
	shl b32 $r8 2
	add b32 $r9 $r8
	add b32 $r14 4
	cmpu b32 $r14 $r15
	bra ne nv_mmctx_size_loop
	mov b32 $r15 $r9
	ret

	// mmctx_xfer - execute a list of mmio transfers
	//
	// In : $r10 flags
	// bit 0: direction (0 = save, 1 = load)
	// bit 1: set if first transfer
	// bit 2: set if last transfer
	// $r11 base
	// $r12 mmio list head
	// $r13 mmio list tail
	// $r14 multi_stride
	// $r15 multi_mask
	//
	mmctx_xfer:
	trace_set(T_MMCTX)
	mov $r8 0x710
	shl b32 $r8 6
	clear b32 $r9
	or $r11 $r11
	bra e mmctx_base_disabled
	iowr I[$r8 + 0x000] $r11 // MMCTX_BASE
	bset $r9 0 // BASE_EN
	mmctx_base_disabled:
	or $r14 $r14
	bra e mmctx_multi_disabled
	iowr I[$r8 + 0x200] $r14 // MMCTX_MULTI_STRIDE
	iowr I[$r8 + 0x300] $r15 // MMCTX_MULTI_MASK
	bset $r9 1 // MULTI_EN
	mmctx_multi_disabled:
	add b32 $r8 0x100

	xbit $r11 $r10 0
	shl b32 $r11 16 // DIR
	bset $r11 12 // QLIMIT = 0x10
	xbit $r14 $r10 1
	shl b32 $r14 17
	or $r11 $r14 // START_TRIGGER
	iowr I[$r8 + 0x000] $r11 // MMCTX_CTRL

	// loop over the mmio list, and send requests to the hw
	mmctx_exec_loop:
	// wait for space in mmctx queue
	mmctx_wait_free:
	iord $r14 I[$r8 + 0x000] // MMCTX_CTRL
	and $r14 0x1f
	bra e mmctx_wait_free

	// queue up an entry
	ld b32 $r14 D[$r12]
	or $r14 $r9
	iowr I[$r8 + 0x300] $r14
	add b32 $r12 4
	cmpu b32 $r12 $r13
	bra ne mmctx_exec_loop

	xbit $r11 $r10 2
	bra ne mmctx_stop
	// wait for queue to empty
	mmctx_fini_wait:
	iord $r11 I[$r8 + 0x000] // MMCTX_CTRL
	and $r11 0x1f
	cmpu b32 $r11 0x10
	bra ne mmctx_fini_wait
	mov $r10 2 // DONE_MMCTX
	call wait_donez
	bra mmctx_done
	mmctx_stop:
	xbit $r11 $r10 0
	shl b32 $r11 16 // DIR
	bset $r11 12 // QLIMIT = 0x10
	bset $r11 18 // STOP_TRIGGER
	iowr I[$r8 + 0x000] $r11 // MMCTX_CTRL
	mmctx_stop_wait:
	// wait for STOP_TRIGGER to clear
	iord $r11 I[$r8 + 0x000] // MMCTX_CTRL
	xbit $r11 $r11 18
	bra ne mmctx_stop_wait
	mmctx_done:
	trace_clr(T_MMCTX)
	ret

	// Wait for DONE_STRAND
	//
	strand_wait:
	push $r10
	mov $r10 2
	call wait_donez
	pop $r10
	ret

	// unknown - call before issuing strand commands
	//
	strand_pre:
	mov $r8 0x4afc
	sethi $r8 0x20000
	mov $r9 0xc
	iowr I[$r8] $r9
	call strand_wait
	ret

	// unknown - call after issuing strand commands
	//
	strand_post:
	mov $r8 0x4afc
	sethi $r8 0x20000
	mov $r9 0xd
	iowr I[$r8] $r9
	call strand_wait
	ret

	// Selects strand set?!
	//
	// In: $r14 id
	//
	strand_set:
	mov $r10 0x4ffc
	sethi $r10 0x20000
	sub b32 $r11 $r10 0x500
	mov $r12 0xf
	iowr I[$r10 + 0x000] $r12 // 0x93c = 0xf
	mov $r12 0xb
	iowr I[$r11 + 0x000] $r12 // 0x928 = 0xb
	call strand_wait
	iowr I[$r10 + 0x000] $r14 // 0x93c = <id>
	mov $r12 0xa
	iowr I[$r11 + 0x000] $r12 // 0x928 = 0xa
	call strand_wait
	ret

	// Initialise strand context data
	//
	// In : $r15 context base
	// Out: $r15 context size (in bytes)
	//
	// Strandset(?) 3 hardcoded currently
	//
	strand_ctx_init:
	trace_set(T_STRINIT)
	call strand_pre
	mov $r14 3
	call strand_set
	mov $r10 0x46fc
	sethi $r10 0x20000
	add b32 $r11 $r10 0x400
	iowr I[$r10 + 0x100] $r0 // STRAND_FIRST_GENE = 0
	mov $r12 1
	iowr I[$r11 + 0x000] $r12 // STRAND_CMD = LATCH_FIRST_GENE
	call strand_wait
	sub b32 $r12 $r0 1
	iowr I[$r10 + 0x000] $r12 // STRAND_GENE_CNT = 0xffffffff
	mov $r12 2
	iowr I[$r11 + 0x000] $r12 // STRAND_CMD = LATCH_GENE_CNT
	call strand_wait
	call strand_post

	// read the size of each strand, poke the context offset of
	// each into STRAND_{SAVE,LOAD}_SWBASE now, no need to worry
	// about it later then.
	mov $r8 0x880
	shl b32 $r8 6
	iord $r9 I[$r8 + 0x000] // STRANDS
	add b32 $r8 0x2200
	shr b32 $r14 $r15 8
	ctx_init_strand_loop:
	iowr I[$r8 + 0x000] $r14 // STRAND_SAVE_SWBASE
	iowr I[$r8 + 0x100] $r14 // STRAND_LOAD_SWBASE
	iord $r10 I[$r8 + 0x200] // STRAND_SIZE
	shr b32 $r10 6
	add b32 $r10 1
	add b32 $r14 $r10
	add b32 $r8 4
	sub b32 $r9 1
	bra ne ctx_init_strand_loop

	shl b32 $r14 8
	sub b32 $r15 $r14 $r15
	trace_clr(T_STRINIT)
	ret
	')