| /* |
| * (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 |