170 lines
4.5 KiB
ArmAsm
170 lines
4.5 KiB
ArmAsm
/*
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* Copyright (C) 2001,2002,2003 Broadcom Corporation
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <asm/asm.h>
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#include <asm/regdef.h>
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#include <asm/mipsregs.h>
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#include <asm/stackframe.h>
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#include <asm/cacheops.h>
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#include <asm/sibyte/board.h>
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#define C0_ERRCTL $26 /* CP0: Error info */
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#define C0_CERR_I $27 /* CP0: Icache error */
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#define C0_CERR_D $27,1 /* CP0: Dcache error */
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/*
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* Based on SiByte sample software cache-err/cerr.S
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* CVS revision 1.8. Only the 'unrecoverable' case
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* is changed.
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*/
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.set mips64
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.set noreorder
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.set noat
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/*
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* sb1_cerr_vec: code to be copied to the Cache Error
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* Exception vector. The code must be pushed out to memory
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* (either by copying to Kseg0 and Kseg1 both, or by flushing
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* the L1 and L2) since it is fetched as 0xa0000100.
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*
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* NOTE: Be sure this handler is at most 28 instructions long
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* since the final 16 bytes of the exception vector memory
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* (0x170-0x17f) are used to preserve k0, k1, and ra.
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*/
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LEAF(except_vec2_sb1)
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/*
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* If this error is recoverable, we need to exit the handler
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* without having dirtied any registers. To do this,
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* save/restore k0 and k1 from low memory (Useg is direct
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* mapped while ERL=1). Note that we can't save to a
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* CPU-specific location without ruining a register in the
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* process. This means we are vulnerable to data corruption
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* whenever the handler is reentered by a second CPU.
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*/
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sd k0,0x170($0)
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sd k1,0x178($0)
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#ifdef CONFIG_SB1_CEX_ALWAYS_FATAL
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j handle_vec2_sb1
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nop
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#else
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/*
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* M_ERRCTL_RECOVERABLE is bit 31, which makes it easy to tell
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* if we can fast-path out of here for a h/w-recovered error.
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*/
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mfc0 k1,C0_ERRCTL
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bgtz k1,attempt_recovery
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sll k0,k1,1
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recovered_dcache:
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/*
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* Unlock CacheErr-D (which in turn unlocks CacheErr-DPA).
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* Ought to log the occurrence of this recovered dcache error.
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*/
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b recovered
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mtc0 $0,C0_CERR_D
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attempt_recovery:
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/*
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* k0 has C0_ERRCTL << 1, which puts 'DC' at bit 31. Any
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* Dcache errors we can recover from will take more extensive
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* processing. For now, they are considered "unrecoverable".
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* Note that 'DC' becoming set (outside of ERL mode) will
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* cause 'IC' to clear; so if there's an Icache error, we'll
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* only find out about it if we recover from this error and
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* continue executing.
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*/
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bltz k0,unrecoverable
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sll k0,1
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/*
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* k0 has C0_ERRCTL << 2, which puts 'IC' at bit 31. If an
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* Icache error isn't indicated, I'm not sure why we got here.
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* Consider that case "unrecoverable" for now.
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*/
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bgez k0,unrecoverable
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attempt_icache_recovery:
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/*
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* External icache errors are due to uncorrectable ECC errors
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* in the L2 cache or Memory Controller and cannot be
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* recovered here.
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*/
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mfc0 k0,C0_CERR_I /* delay slot */
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li k1,1 << 26 /* ICACHE_EXTERNAL */
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and k1,k0
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bnez k1,unrecoverable
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andi k0,0x1fe0
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/*
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* Since the error is internal, the 'IDX' field from
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* CacheErr-I is valid and we can just invalidate all blocks
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* in that set.
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*/
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cache Index_Invalidate_I,(0<<13)(k0)
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cache Index_Invalidate_I,(1<<13)(k0)
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cache Index_Invalidate_I,(2<<13)(k0)
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cache Index_Invalidate_I,(3<<13)(k0)
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/* Ought to log this recovered icache error */
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recovered:
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/* Restore the saved registers */
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ld k0,0x170($0)
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ld k1,0x178($0)
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eret
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unrecoverable:
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/* Unrecoverable Icache or Dcache error; log it and/or fail */
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j handle_vec2_sb1
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nop
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#endif
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END(except_vec2_sb1)
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LEAF(handle_vec2_sb1)
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mfc0 k0,CP0_CONFIG
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li k1,~CONF_CM_CMASK
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and k0,k0,k1
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ori k0,k0,CONF_CM_UNCACHED
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mtc0 k0,CP0_CONFIG
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SSNOP
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SSNOP
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SSNOP
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SSNOP
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bnezl $0, 1f
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1:
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mfc0 k0, CP0_STATUS
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sll k0, k0, 3 # check CU0 (kernel?)
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bltz k0, 2f
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nop
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/* Get a valid Kseg0 stack pointer. Any task's stack pointer
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* will do, although if we ever want to resume execution we
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* better not have corrupted any state. */
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get_saved_sp
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move sp, k1
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2:
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j sb1_cache_error
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nop
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END(handle_vec2_sb1)
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