binutils-gdb/ld/emultempl/spu_ovl.S
2006-10-25 06:49:21 +00:00

276 lines
6.2 KiB
ArmAsm

/* Overlay manager for SPU.
Copyright 2006 Free Software Foundation, Inc.
This file is part of GLD, the Gnu Linker.
GLD is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GLD is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GLD; see the file COPYING. If not, write to the Free
Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
02110-1301, USA. */
/**
* MFC DMA defn's.
*/
#define MFC_GET_CMD 0x40
#define MFC_MAX_DMA_SIZE 0x4000
#define MFC_TAG_UPDATE_ALL 2
#define MFC_TAG_ID 0
/**
* Temporary register allocations.
* These are saved/restored here.
*/
#define tab $75
#define cgbits $75
#define add64 $75
#define ealo $75
#define newmask $75
#define tagstat $75
#define bchn $75
#define rv1 $75
#define off $76
#define off64 $76
#define maxsize $76
#define oldmask $76
#define sz $76
#define lnkr $76
#define rv2 $76
#define cur $77
#define cmp $77
#define buf $77
#define genwi $77
#define tagid $77
#define cmd $77
#define rv3 $77
#define cgshuf $78
#define vma $6
#define map $7
#define size $7
#define cmp2 $7
#define ea64 $8
#define retval $8
#ifdef OVLY_IRQ_SAVE
#define irqtmp $8
#define irq_stat $9
#endif
.extern _ovly_table
.extern _ovly_buf_table
.text
.align 4
__rv_pattern:
.word 0x00010203, 0x1c1d1e1f, 0x00010203, 0x10111213
__cg_pattern:
.word 0x04050607, 0x80808080, 0x80808080, 0x80808080
/**
* __ovly_return - stub for returning from overlay functions.
*
* inputs:
* $lr link register
*
* outputs:
* $78 old partition number, to be reloaded
* $79 return address in old partion number
*/
.global __ovly_return
.type __ovly_return, @function
.word 0
__ovly_return:
shlqbyi $78, $lr, 4
shlqbyi $79, $lr, 8
biz $78, $79
/**
* __ovly_load - copy an overlay partion to local store.
*
* inputs:
* $78 partition number to be loaded.
* $79 branch target in new partition.
* $lr link register, containing return addr.
*
* outputs:
* $lr new link register, returning through __ovly_return.
*
* Copy a new overlay partition into local store, or return
* immediately if the partition is already resident.
*/
.global __ovly_load
.type __ovly_load, @function
__ovly_load:
/* Save temporary registers to stack. */
stqd $6, -16($sp)
stqd $7, -32($sp)
stqd $8, -48($sp)
#ifdef OVLY_IRQ_SAVE
/* Save irq state, then disable interrupts. */
stqd $9, -64($sp)
ila irqtmp, __ovly_irq_save
rdch irq_stat, $SPU_RdMachStat
bid irqtmp
__ovly_irq_save:
#endif
/* Set branch hint to overlay target. */
hbr __ovly_load_ret, $79
/* Get caller's overlay index by back chaining through stack frames.
* Loop until end of stack (back chain all-zeros) or
* encountered a link register we set here. */
lqd bchn, 0($sp)
ila retval, __ovly_return
__ovly_backchain_loop:
lqd lnkr, 16(bchn)
lqd bchn, 0(bchn)
ceq cmp, lnkr, retval
ceqi cmp2, bchn, 0
or cmp, cmp, cmp2
brz cmp, __ovly_backchain_loop
/* If we reached the zero back-chain, then lnkr is bogus. Clear the
* part of lnkr that we use later (slot 3). */
rotqbyi cmp2, cmp2, 4
andc lnkr, lnkr, cmp2
/* Set lr = {__ovly_return, prev ovl ndx, caller return adr, callee ovl ndx}. */
lqd rv1, (__rv_pattern-__ovly_return+4)(retval)
shufb rv2, retval, lnkr, rv1
shufb rv3, $lr, $78, rv1
fsmbi rv1, 0xff
selb $lr, rv2, rv3, rv1
/* Branch to $79 if non-overlay */
brz $78, __ovly_load_restore
/* Load values from _ovly_table[$78].
* extern struct {
* u32 vma;
* u32 size;
* u32 file_offset;
* u32 buf;
* } _ovly_table[];
*/
shli off, $78, 4
ila tab, _ovly_table - 16
lqx vma, tab, off
rotqbyi buf, vma, 12
/* Load values from _ovly_buf_table[buf].
* extern struct {
* u32 mapped;
* } _ovly_buf_table[];
*/
ila tab, _ovly_buf_table
ai off, buf, -1
shli off, off, 2
lqx map, tab, off
rotqby cur, map, off
/* Branch to $79 now if overlay is already mapped. */
ceq cmp, $78, cur
brnz cmp, __ovly_load_restore
/* Set _ovly_buf_table[buf].mapped = $78. */
cwx genwi, tab, off
shufb map, $78, map, genwi
stqx map, tab, off
/* A new partition needs to be loaded. Prepare for DMA loop.
* _EAR_ is the 64b base EA, filled in at run time by the
* loader, and indicating the value for SPU executable image start.
*/
lqd cgshuf, (__cg_pattern-__ovly_return+4)(retval)
rotqbyi size, vma, 4
rotqbyi sz, vma, 8
lqa ea64, _EAR_
__ovly_xfer_loop:
/* 64b add to compute next ea64. */
rotqmbyi off64, sz, -4
cg cgbits, ea64, off64
shufb add64, cgbits, cgbits, cgshuf
addx add64, ea64, off64
ori ea64, add64, 0
/* Setup DMA parameters, then issue DMA request. */
rotqbyi ealo, add64, 4
ila maxsize, MFC_MAX_DMA_SIZE
cgt cmp, size, maxsize
selb sz, size, maxsize, cmp
ila tagid, MFC_TAG_ID
wrch $MFC_LSA, vma
wrch $MFC_EAH, ea64
wrch $MFC_EAL, ealo
wrch $MFC_Size, sz
wrch $MFC_TagId, tagid
ila cmd, MFC_GET_CMD
wrch $MFC_Cmd, cmd
/* Increment vma, decrement size, branch back as needed. */
a vma, vma, sz
sf size, sz, size
brnz size, __ovly_xfer_loop
/* Save app's tagmask, wait for DMA complete, restore mask. */
rdch oldmask, $MFC_RdTagMask
#if MFC_TAG_ID < 16
ilh newmask, 1 << MFC_TAG_ID
#else
ilhu newmask, 1 << (MFC_TAG_ID - 16)
#endif
wrch $MFC_WrTagMask, newmask
ila tagstat, MFC_TAG_UPDATE_ALL
wrch $MFC_WrTagUpdate, tagstat
rdch tagstat, $MFC_RdTagStat
sync
wrch $MFC_WrTagMask, oldmask
.global _ovly_debug_event
.type _ovly_debug_event, @function
_ovly_debug_event:
/* GDB inserts debugger trap here. */
nop
__ovly_load_restore:
#ifdef OVLY_IRQ_SAVE
/* Conditionally re-enable interrupts. */
andi irq_stat, irq_stat, 1
ila irqtmp, __ovly_irq_restore
binze irq_stat, irqtmp
__ovly_irq_restore:
lqd $9, -64($sp)
#endif
/* Restore saved registers. */
lqd $8, -48($sp)
lqd $7, -32($sp)
lqd $6, -16($sp)
__ovly_load_ret:
/* Branch to target address. */
bi $79