+++ /dev/null
-/*
- * (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 */
-
-/*************************************************************************
- * GDB stubs
- ************************************************************************/
- .text
- .global _brkpt_hw_int, _brkpt_sw_int
- .align 4
-
-_brkpt_hw_int:
- movi %l1, 9
- pfx 3
- wrctl %l1
- pfx 4
- wrctl %l1
-
-_brkpt_sw_int:
- movi %l1, 9
- pfx 3
- wrctl %l1
- pfx 4
- wrctl %l1
-
- tret %o7
projects / u-boot / blobdiff