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Diffstat (limited to 'cpu/nios/traps.S')
| -rw-r--r-- | cpu/nios/traps.S | 582 |
1 files changed, 0 insertions, 582 deletions
diff --git a/cpu/nios/traps.S b/cpu/nios/traps.S deleted file mode 100644 index bc4d3f6..0000000 --- a/cpu/nios/traps.S +++ /dev/null @@ -1,582 +0,0 @@ -/* - * (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 |