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/*
* (C) Copyright 2003, Psyent Corporation <www.psyent.com>
* Scott McNutt <smcnutt@psyent.com>
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program 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 of
* the License, or (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <config.h>
/*************************************************************************
* Register window underflow
*
* The register window underflow exception occurs whenever the lowest
* valid register window is in use (CWP=LO_LIMIT) and a save instruction
* is issued. The save moves CWP below LO_LIMIT, %sp is set as normal,
* then the exception is generated prior to executing the instruction
* after the save.
************************************************************************/
.text
.global _cwp_lolimit
.align 4
_cwp_lolimit:
/* Sixteen words are always allocated by the compiler in every
* procedure's stack frame, always starting at %sp, for saving
* 'in' and 'local' registers on a window overflow.
*
* Save the 'global' and 'in' regs on stack. They are restored
* at cwp = HI_LIMIT. The 'local' regs aren't in-use at this point.
*/
sts [%sp,0], %g0 /* Save 'global' regs*/
sts [%sp,1], %g1
sts [%sp,2], %g2
sts [%sp,3], %g3
sts [%sp,4], %g4
sts [%sp,5], %g5
sts [%sp,6], %g6
sts [%sp,7], %g7
sts [%sp,8], %i0 /* Save 'in' regs */
sts [%sp,9], %i1
sts [%sp,10], %i2
sts [%sp,11], %i3
sts [%sp,12], %i4
sts [%sp,13], %i5
sts [%sp,14], %i6
sts [%sp,15], %i7
/* Save current %sp and return address in a global so they are
* available at cwp = HI_LIMIT ... where the 'global'/'in' regs
* are restored. NOTE: %sp changes with cwp.
*/
mov %g7, %o7
mov %g6, %sp
/* Get LO_LIMIT/HI_LIMIT to know where to start & stop. Note: in
* the underflow exception, cwp is __NOT__ guaranteed to be zero.
* If the OCI debug module is enabled the reset value for LO_LIMIT
* is 2, not 1 -- so cwp can be 1 or 0.
*/
pfx 2 /* WVALID */
rdctl %g1
mov %g2, %g1
pfx 0
and %g1, 0x1f /* g1 <- LO_LIMIT */
lsri %g2, 5
pfx 0
and %g2,0x1f /* g2 <- HI_LIMIT */
/* Set istatus so cwp = HI_LIMIT after tret
*/
movi %g5, 0x1f
lsli %g5, 4
not %g5 /* mask to clr cwp */
pfx 1 /* istatus */
rdctl %g0
and %g0, %g5 /* clear cwp field */
mov %g4, %g2
lsli %g4, 4
or %g0, %g4 /* cwp = HI_LIMIT */
pfx 1
wrctl %g0 /* update istatus */
/* Now move up the register file, saving as we go. When loop
* is first entered, %g1 is at LO_LIMIT.
*/
0:
restore /* cwp++ */
sts [%sp,0], %l0 /* Save "local" regs*/
sts [%sp,1], %l1
sts [%sp,2], %l2
sts [%sp,3], %l3
sts [%sp,4], %l4
sts [%sp,5], %l5
sts [%sp,6], %l6
sts [%sp,7], %l7
sts [%sp,8], %i0 /* Save 'in' regs */
sts [%sp,9], %i1
sts [%sp,10], %i2
sts [%sp,11], %i3
sts [%sp,12], %i4
sts [%sp,13], %i5
sts [%sp,14], %i6
sts [%sp,15], %i7
cmp %g1, %g2 /* cwp == HI_LIMIT ? */
skps cc_ne /* if so, we're done */
br 1f
nop /* delay slot */
inc %g1 /* g1 <- cwp++ */
br 0b
nop /* delay slot */
/* At this point cwp = HI_LIMIT, so the global/in regs that were
* in place when the underflow occurred must be restored using
* the original stack pointer (saved in g6).
*/
1:
mov %o7, %g7 /* restore return addr */
mov %sp, %g6 /* Restore original sp */
lds %g0, [%sp,0] /* Restore 'global' regs*/
lds %g1, [%sp,1]
lds %g2, [%sp,2]
lds %g3, [%sp,3]
lds %g4, [%sp,4]
lds %g5, [%sp,5]
lds %g6, [%sp,6]
lds %g7, [%sp,7]
lds %i0, [%sp,8] /* Restore 'in' regs*/
lds %i1, [%sp,9]
lds %i2, [%sp,10]
lds %i3, [%sp,11]
lds %i4, [%sp,12]
lds %i5, [%sp,13]
lds %i6, [%sp,14]
lds %i7, [%sp,15]
tret %o7 /* All done */
/*************************************************************************
* Register window overflow
*
* The register window overflow exception occurs whenever the highest
* valid register window is in use (cwp = HI_LIMIT) and a restore
* instruction is issued. Control is transferred to the overflow handler
* before the instruction following restore is executed.
*
* When a register window overflow exception is taken, the exception
* handler sees cwp at HI_LIMIT.
************************************************************************/
.text
.global _cwp_hilimit
.align 4
_cwp_hilimit:
/* Save 'global'/'in' regs on the stack -- will restore when cwp
* is at LO_LIMIT. Locals don't need saving as they are going away.
*/
sts [%sp,0], %g0 /* Save "global" regs*/
sts [%sp,1], %g1
sts [%sp,2], %g2
sts [%sp,3], %g3
sts [%sp,4], %g4
sts [%sp,5], %g5
sts [%sp,6], %g6
sts [%sp,7], %g7
sts [%sp,8], %i0 /* Save 'in' regs */
sts [%sp,9], %i1
sts [%sp,10], %i2
sts [%sp,11], %i3
sts [%sp,12], %i4
sts [%sp,13], %i5
sts [%sp,14], %i6
sts [%sp,15], %i7
/* The current %sp must be available in global to restore regs
* saved on stack. Need return addr as well ;-)
*/
mov %g7, %o7
mov %g6, %sp
/* Get HI_LIMIT & LO_LIMIT
*/
pfx 2 /* WVALID */
rdctl %g1
mov %g2, %g1
pfx 0
and %g1, 0x1f /* g1 <- LO_LIMIT */
lsri %g2, 5
pfx 0
and %g2,0x1f /* g2 <- HI_LIMIT */
/* Set istatus so cwp = LO_LIMIT after tret
*/
movi %g5, 0x1f
lsli %g5, 4
not %g5 /* mask to clr cwp */
pfx 1 /* istatus */
rdctl %g0
and %g0, %g5 /* clear cwp field */
mov %g4, %g1 /* g4 <- LO_LIMIT */
lsli %g4, 4
or %g0, %g4 /* cwp = LO_LIMIT */
pfx 1
wrctl %g0 /* update istatus */
/* Move to cwp = LO_LIMIT-1 and restore 'in' regs.
*/
subi %g4,(1 << 4) /* g4 <- LO_LIMIT - 1 */
rdctl %g0
and %g0, %g5 /* clear cwp field */
or %g0, %g4 /* cwp = LO_LIMIT - 1 */
wrctl %g0 /* update status */
nop
mov %sp, %g6 /* Restore sp */
lds %i0, [%sp,8] /* Restore 'in' regs */
lds %i1, [%sp,9]
lds %i2, [%sp,10]
lds %i3, [%sp,11]
lds %i4, [%sp,12]
lds %i5, [%sp,13]
lds %i6, [%sp,14] /* sp in next window */
lds %i7, [%sp,15]
/* Starting at LO_LIMIT-1, move up the register file, restoring
* along the way.
*/
0:
restore /* cwp++ */
lds %l0, [%sp,0] /* Restore 'local' regs*/
lds %l1, [%sp,1]
lds %l2, [%sp,2]
lds %l3, [%sp,3]
lds %l4, [%sp,4]
lds %l5, [%sp,5]
lds %l6, [%sp,6]
lds %l7, [%sp,7]
lds %i0, [%sp,8] /* Restore 'in' regs */
lds %i1, [%sp,9]
lds %i2, [%sp,10]
lds %i3, [%sp,11]
lds %i4, [%sp,12]
lds %i5, [%sp,13]
lds %i6, [%sp,14] /* sp in next window */
lds %i7, [%sp,15]
cmp %g1, %g2 /* cwp == HI_LIMIT ? */
skps cc_ne /* if so, we're done */
br 1f
nop /* delay slot */
inc %g1 /* cwp++ */
br 0b
nop /* delay slot */
/* All windows have been updated at this point, but the globals
* still need to be restored. Go to cwp = LO_LIMIT-1 to get
* some registers to use.
*/
1:
rdctl %g0
and %g0, %g5 /* clear cwp field */
or %g0, %g4 /* cwp = LO_LIMIT - 1 */
wrctl %g0 /* update status */
nop
/* Now there are some registers available to use in restoring
* the globals.
*/
mov %sp, %g6
mov %o7, %g7
lds %g0, [%sp,0] /* Restore "global" regs*/
lds %g1, [%sp,1]
lds %g2, [%sp,2]
lds %g3, [%sp,3]
lds %g4, [%sp,4]
lds %g5, [%sp,5]
lds %g6, [%sp,6]
lds %g7, [%sp,7]
/* The tret moves istatus -> status. istatus was already set for
* cwp = LO_LIMIT.
*/
tret %o7 /* done */
/*************************************************************************
* Default exception handler
*
* The default handler passes control to external_interrupt(). So trap
* or hardware interrupt hanlders can be installed using the familiar
* irq_install_handler().
*
* Here, the stack is fixed-up and cwp is incremented prior to calling
* external_interrupt(). This lets the underflow and overflow handlers
* operate normally during the exception.
************************************************************************/
.text
.global _def_xhandler
.align 4
_def_xhandler:
/* Allocate some stack space: 16 words at %sp to accomodate
* a reg window underflow, 8 words to save interrupted task's
* 'out' regs (which are now the 'in' regs), 8 words to preserve
* the 'global' regs and 3 words to save the return address,
* status and istatus. istatus must be saved in the event an
* underflow occurs in a dispatched handler. status is saved so
* a handler can access it on stack.
*/
pfx %hi((16+16+3) * 4)
subi %fp, %lo((16+16+3) * 4)
mov %sp, %fp
/* Save the 'global' regs and the interrupted task's 'out' regs
* (our 'in' regs) along with the return addr, status & istatus.
* First 16 words are for underflow exception.
*/
rdctl %l0 /* status */
pfx 1 /* istatus */
rdctl %l1
sts [%sp,16+0], %g0 /* Save 'global' regs*/
sts [%sp,16+1], %g1
sts [%sp,16+2], %g2
sts [%sp,16+3], %g3
sts [%sp,16+4], %g4
sts [%sp,16+5], %g5
sts [%sp,16+6], %g6
sts [%sp,16+7], %g7
sts [%sp,16+8], %i0 /* Save 'in' regs */
sts [%sp,16+9], %i1
sts [%sp,16+10], %i2
sts [%sp,16+11], %i3
sts [%sp,16+12], %i4
sts [%sp,16+13], %i5
sts [%sp,16+14], %i6
sts [%sp,16+15], %i7
sts [%sp,16+16], %l0 /* status */
sts [%sp,16+17], %l1 /* istatus */
sts [%sp,16+18], %o7 /* return addr */
/* Move to cwp+1 ... this guarantees cwp is at or above LO_LIMIT.
* Need to set IPRI=3 and IE=1 to enable underflow exceptions.
* NOTE: only the 'out' regs have been saved ... can't touch
* the 'in' or 'local' here.
*/
restore /* cwp++ */
rdctl %o0 /* o0 <- status */
pfx %hi(0x7e00)
movi %o1, %lo(0x7e00)
not %o1
and %o0, %o1 /* clear IPRI */
pfx %hi(0x8600)
movi %o1, %lo(0x8600)
or %o0, %o1 /* IPRI=3, IE=1 */
wrctl %o0 /* o0 -> status */
nop
/* It's ok to call a C routine now since cwp >= LO_LIMIT,
* interrupt task's registers are/will be preserved, and
* underflow exceptions can be handled.
*/
pfx %hi(external_interrupt@h)
movi %o1, %lo(external_interrupt@h)
pfx %xhi(external_interrupt@h)
movhi %o1, %xlo(external_interrupt@h)
bgen %o0, 4+2 /* 16 * 4 */
add %o0, %sp /* Ptr to regs */
call %o1
nop
/* Move back to the exception register window, restore the 'out'
* registers, then return from exception.
*/
rdctl %o0 /* o0 <- status */
subi %o0, 16
wrctl %o0 /* cwp-- */
nop
mov %sp, %fp
lds %g0, [%sp,16+0] /* Restore 'global' regs*/
lds %g1, [%sp,16+1]
lds %g2, [%sp,16+2]
lds %g3, [%sp,16+3]
lds %g4, [%sp,16+4]
lds %g5, [%sp,16+5]
lds %g6, [%sp,16+6]
lds %g7, [%sp,16+7]
lds %i0, [%sp,16+8] /* Restore 'in' regs*/
lds %i1, [%sp,16+9]
lds %i2, [%sp,16+10]
lds %i3, [%sp,16+11]
lds %i4, [%sp,16+12]
lds %i5, [%sp,16+13]
lds %i6, [%sp,16+14]
lds %i7, [%sp,16+15]
lds %l0, [%sp,16+16] /* status */
lds %l1, [%sp,16+17] /* istatus */
lds %o7, [%sp,16+18] /* return addr */
pfx 1
wrctl %l1 /* restore istatus */
pfx %hi((16+16+3) * 4)
addi %sp, %lo((16+16+3) * 4)
mov %fp, %sp
tret %o7 /* Done */
/*************************************************************************
* Timebase Timer Interrupt -- This has identical structure to above,
* but calls timer_interrupt(). Doing it this way keeps things similar
* to other architectures (e.g. ppc).
************************************************************************/
.text
.global _timebase_int
.align 4
_timebase_int:
/* Allocate stack space.
*/
pfx %hi((16+16+3) * 4)
subi %fp, %lo((16+16+3) * 4)
mov %sp, %fp
/* Save the 'global' regs & 'out' regs (our 'in' regs)
*/
rdctl %l0 /* status */
pfx 1 /* istatus */
rdctl %l1
sts [%sp,16+0], %g0 /* Save 'global' regs*/
sts [%sp,16+1], %g1
sts [%sp,16+2], %g2
sts [%sp,16+3], %g3
sts [%sp,16+4], %g4
sts [%sp,16+5], %g5
sts [%sp,16+6], %g6
sts [%sp,16+7], %g7
sts [%sp,16+8], %i0 /* Save 'in' regs */
sts [%sp,16+9], %i1
sts [%sp,16+10], %i2
sts [%sp,16+11], %i3
sts [%sp,16+12], %i4
sts [%sp,16+13], %i5
sts [%sp,16+14], %i6
sts [%sp,16+15], %i7
sts [%sp,16+16], %l0 /* status */
sts [%sp,16+17], %l1 /* istatus */
sts [%sp,16+18], %o7 /* return addr */
/* Move to cwp+1.
*/
restore /* cwp++ */
rdctl %o0 /* o0 <- status */
pfx %hi(0x7e00)
movi %o1, %lo(0x7e00)
not %o1
and %o0, %o1 /* clear IPRI */
pfx %hi(0x8600)
movi %o1, %lo(0x8600)
or %o0, %o1 /* IPRI=3, IE=1 */
wrctl %o0 /* o0 -> status */
nop
/* Call timer_interrupt()
*/
pfx %hi(timer_interrupt@h)
movi %o1, %lo(timer_interrupt@h)
pfx %xhi(timer_interrupt@h)
movhi %o1, %xlo(timer_interrupt@h)
bgen %o0, 4+2 /* 16 * 4 */
add %o0, %sp /* Ptr to regs */
call %o1
nop
/* Move back to the exception register window, restore the 'out'
* registers, then return from exception.
*/
rdctl %o0 /* o0 <- status */
subi %o0, 16
wrctl %o0 /* cwp-- */
nop
mov %sp, %fp
lds %g0, [%sp,16+0] /* Restore 'global' regs*/
lds %g1, [%sp,16+1]
lds %g2, [%sp,16+2]
lds %g3, [%sp,16+3]
lds %g4, [%sp,16+4]
lds %g5, [%sp,16+5]
lds %g6, [%sp,16+6]
lds %g7, [%sp,16+7]
lds %i0, [%sp,16+8] /* Restore 'in' regs*/
lds %i1, [%sp,16+9]
lds %i2, [%sp,16+10]
lds %i3, [%sp,16+11]
lds %i4, [%sp,16+12]
lds %i5, [%sp,16+13]
lds %i6, [%sp,16+14]
lds %i7, [%sp,16+15]
lds %l0, [%sp,16+16] /* status */
lds %l1, [%sp,16+17] /* istatus */
lds %o7, [%sp,16+18] /* return addr */
pfx 1
wrctl %l1 /* restore istatus */
pfx %hi((16+16+3) * 4)
addi %sp, %lo((16+16+3) * 4)
mov %fp, %sp
tret %o7 /* Done */
|
