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author | Frank Ch. Eigler <fche@redhat.com> | 1998-10-29 13:44:37 +0000 |
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committer | Frank Ch. Eigler <fche@redhat.com> | 1998-10-29 13:44:37 +0000 |
commit | fd6e6422c8e6aa216a5a4b154d1f3dde44797126 (patch) | |
tree | 3cf2824ca1678c60ff1d5d99f374125eb0b93635 /sim/mips/sim-main.c | |
parent | 0d51822e3b242ae92490a61e0fd0f175b2481091 (diff) | |
download | gdb-fd6e6422c8e6aa216a5a4b154d1f3dde44797126.zip gdb-fd6e6422c8e6aa216a5a4b154d1f3dde44797126.tar.gz gdb-fd6e6422c8e6aa216a5a4b154d1f3dde44797126.tar.bz2 |
* sky->devo merge, continued -- left out the r5900 TLB last time!
* includes a small PR 17224 tweak
Diffstat (limited to 'sim/mips/sim-main.c')
-rw-r--r-- | sim/mips/sim-main.c | 334 |
1 files changed, 299 insertions, 35 deletions
diff --git a/sim/mips/sim-main.c b/sim/mips/sim-main.c index 8bbea01..9e2ea40 100644 --- a/sim/mips/sim-main.c +++ b/sim/mips/sim-main.c @@ -1,26 +1,27 @@ -/* Simulator for the MIPS architecture. +/* Copyright (C) 1998, Cygnus Solutions - This file is part of the MIPS sim + 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 SOFTWARE IS NOT COPYRIGHTED + 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. - Cygnus offers the following for use in the public domain. Cygnus - makes no warranty with regard to the software or it's performance - and the user accepts the software "AS IS" with all faults. + 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. - CYGNUS DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD TO - THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF - MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + */ - $Revision$ - $Date$ - - */ #ifndef SIM_MAIN_C #define SIM_MAIN_C #include "sim-main.h" +#include "sim-assert.h" #if !(WITH_IGEN) #define SIM_MANIFESTS @@ -33,8 +34,12 @@ /*-- simulator engine -------------------------------------------------------*/ /*---------------------------------------------------------------------------*/ +/* start-sanitize-sky */ +#ifdef TARGET_SKY + /* Description from page A-22 of the "MIPS IV Instruction Set" manual (revision 3.1) */ + /* Translate a virtual address to a physical address and cache coherence algorithm describing the mechanism used to resolve the memory reference. Given the virtual address vAddr, and whether the @@ -51,21 +56,292 @@ NOTE: Normally (RAW == 0), when address translation fails, this function raises an exception and does not return. */ +/* This implementation is for the MIPS R4000 family. See MIPS RISC + Architecture, Kane & Heinrich, Chapter 4. It is no good for any + of the 2000, 3000, or 6000 family. + + One possible error in the K&H book of note. K&H has the PFN entry + in the TLB as being 24 bits. The high-order 4 bits would seem to be + unused, as the PFN is only 20-bits long. The 5900 manual shows + this as a 20-bit field. At any rate, the high order 4 bits are + unused. +*/ + + + +/* A place to remember the last cache hit. */ +static r4000_tlb_entry_t *last_hit = 0; + +/* Try to match a single TLB entry. Three possibilities. + 1. No match, returns 0 + 2. Match w/o exception, pAddr and CCA set, returns 1 + 3. Match w/ exception, in which case tlb_try_match does not return. +*/ +INLINE_SIM_MAIN (int) +tlb_try_match (SIM_DESC SD, sim_cpu *CPU, address_word cia, r4000_tlb_entry_t * entry, unsigned32 asid, unsigned32 vAddr, address_word * pAddr, int *CCA, int LorS) +{ + unsigned32 page_mask, vpn2_mask; + page_mask = (entry->mask & 0x01ffe000); + vpn2_mask = ~(page_mask | 0x00001fff); + + if ((vAddr & vpn2_mask) == (entry->hi & vpn2_mask) + && ((entry->hi & TLB_HI_ASID_MASK) == asid + || (entry->hi & TLB_HI_G_MASK) != 0)) + { + /* OK. Now, do we match lo0, or lo1? */ + unsigned32 offset_mask, vpn_lo_mask, vpn_mask, lo; + + offset_mask = (page_mask >> 1) | 0xfff; + vpn_lo_mask = offset_mask + 1; + vpn_mask = ~(offset_mask); + + ASSERT(vpn_lo_mask == (-vpn2_mask) >> 1); + ASSERT(vpn_mask ^ vpn_lo_mask == vpn2_mask); + + if ((vAddr & vpn_lo_mask) == 0) + { + lo = entry->lo0; + } + else + { + lo = entry->lo1; + } + + /* Warn upon attempted use of scratchpad RAM */ + if(entry->lo0 & TLB_LO_S_MASK) + { + sim_io_printf(SD, + "Warning: no scratchpad RAM: virtual 0x%08x maps to physical 0x%08x.\n", + vAddr, (vAddr & offset_mask)); + + /* act as if this is a valid, read/write page. */ + lo = TLB_LO_V_MASK | TLB_LO_D_MASK; + + /* alternately, act as if this TLB entry is not a match */ + /* return 0; */ + } + + if ((lo & TLB_LO_V_MASK) == 0) + { + COP0_BADVADDR = vAddr; + COP0_CONTEXT_set_BADVPN2((vAddr & 0xffffe) >> 19); /* Top 19 bits */ + COP0_ENTRYHI = (vAddr & 0xffffe) | asid; + COP0_RANDOM = rand()%(TLB_SIZE - COP0_WIRED) + COP0_WIRED; + if (LorS == isLOAD) + SignalExceptionTLBInvalidLoad (); + else + SignalExceptionTLBInvalidStore (); + ASSERT(0); /* Signal should never return. */ + } + + if ((lo & TLB_LO_D_MASK) == 0 && (LorS == isSTORE)) + { + COP0_BADVADDR = vAddr; + COP0_CONTEXT_set_BADVPN2((vAddr & 0xffffe) >> 19); /* Top 19 bits */ + COP0_ENTRYHI = (vAddr & 0xffffe) | asid; + COP0_RANDOM = rand()%(TLB_SIZE - COP0_WIRED) + COP0_WIRED; + SignalExceptionTLBModification (); + ASSERT(0); /* Signal should never return. */ + } + + /* Ignore lo.C rule for Cache access */ + + *pAddr = (((lo & 0x03ffffc0) << 6) & (~offset_mask)) + (vAddr & offset_mask); + *CCA = Uncached; /* FOR NOW, no CCA support. */ + + last_hit = entry; /* Remember last hit. */ + + return 1; /* Match */ + } + + return 0; /* No Match */ +} + +static void +dump_tlb(SIM_DESC SD, sim_cpu *CPU, address_word cia) { + + int i; + /* Now linear search for a match. */ + + for (i = 0; i < TLB_SIZE; i++) + { + sim_io_eprintf(SD, "%2d: %08x %08x %08x %08x\n", i, TLB[i].mask, TLB[i].hi, + TLB[i].lo0, TLB[i].lo1); + } +} + + +INLINE_SIM_MAIN (void) +tlb_lookup (SIM_DESC SD, sim_cpu * CPU, address_word cia, unsigned32 vAddr, address_word * pAddr, int *CCA, int LorS) +{ + r4000_tlb_entry_t *p; + unsigned32 asid; + int rc; + + asid = COP0_ENTRYHI & 0x000000ff; + + /* Test last hit first. More code, but probably faster on average. */ + if (last_hit) + { + if (tlb_try_match (SD, CPU, cia, last_hit, asid, vAddr, pAddr, CCA, LorS)) + return; + } + + /* Now linear search for a match. */ + for (p = &TLB[0]; p < &TLB[TLB_SIZE]; p++) + { + if (tlb_try_match (SD, CPU, cia, p, asid, vAddr, pAddr, CCA, LorS)) + return; + } + + /* No match, raise a TLB refill exception. */ + COP0_BADVADDR = vAddr; + COP0_CONTEXT_set_BADVPN2((vAddr & 0xffffe) >> 19); /* Top 19 bits */ + COP0_ENTRYHI = (vAddr & 0xffffe) | asid; + COP0_RANDOM = rand()%(TLB_SIZE - COP0_WIRED) + COP0_WIRED; + +#if 0 +sim_io_eprintf(SD, "TLB Refill exception at address 0x%0x\n", vAddr); +dump_tlb(SD, CPU, cia); +#endif + + if (LorS == isLOAD) + SignalExceptionTLBRefillLoad (); + else + SignalExceptionTLBRefillStore (); + ASSERT(0); /* Signal should never return. */ +} + + INLINE_SIM_MAIN (int) +address_translation (SIM_DESC SD, + sim_cpu * CPU, + address_word cia, + address_word vAddr, + int IorD, + int LorS, + address_word * pAddr, + int *CCA, + int raw) +{ + unsigned32 operating_mode; + unsigned32 asid, vpn, offset, offset_bits; + +#ifdef DEBUG + sim_io_printf (sd, "AddressTranslation(0x%s,%s,%s,...);\n", pr_addr (vAddr), (IorD ? "isDATA" : "isINSTRUCTION"), (LorS ? "iSTORE" : "isLOAD")); +#endif + + vAddr &= 0xFFFFFFFF; + + /* Determine operating mode. */ + operating_mode = SR_KSU; + if (SR & status_ERL || SR & status_EXL) + operating_mode = ksu_kernel; + + switch (operating_mode) + { + case ksu_unknown: + sim_io_eprintf (SD, "Invalid operating mode SR.KSU == 0x3. Treated as 0x0.\n"); + operating_mode = ksu_kernel; + /* Fall-through */ + case ksu_kernel: + /* Map and return for kseg0 and kseg1. */ + if ((vAddr & 0xc0000000) == 0x80000000) + { + ASSERT (0x80000000 <= vAddr && vAddr < 0xc0000000); + if (vAddr < 0xa0000000) + { + /* kseg0: Unmapped, Cached */ + *pAddr = vAddr - 0x80000000; + *CCA = Uncached; /* For now, until cache model is supported. */ + return -1; + } + else + { + /* kseg1: Unmapped, Uncached */ + *pAddr = vAddr - 0xa0000000; + *CCA = Uncached; + return -1; + } + } + break; + + case ksu_supervisor: + { + /* Address error for 0x80000000->0xbfffffff and 0xe00000000->0xffffffff. */ + unsigned32 top_three = vAddr & 0xe0000000; + if (top_three != 0x00000000 && top_three != 0xc0000000) + { + if (LorS == isLOAD) + SignalExceptionAddressLoad (); + else + SignalExceptionAddressStore (); + ASSERT(0); /* Signal should never return. */ + } + } + break; + + case ksu_user: + { + if (vAddr & 0x80000000) + { + if (LorS == isLOAD) + SignalExceptionAddressLoad (); + else + SignalExceptionAddressStore (); + ASSERT(0); /* Signal should never return. */ + } + } + break; + + default: + ASSERT(0); + } + + /* OK. If we got this far, we're ready to use the normal virtual->physical memory mapping. */ + tlb_lookup (SD, CPU, cia, vAddr, pAddr, CCA, LorS); + + /* If the preceding call returns, a match was found, and CCA and pAddr have been set. */ + return -1; +} + +#else /* TARGET_SKY */ +/* end-sanitize-sky */ + +/* Description from page A-22 of the "MIPS IV Instruction Set" manual + (revision 3.1) */ +/* Translate a virtual address to a physical address and cache + coherence algorithm describing the mechanism used to resolve the + memory reference. Given the virtual address vAddr, and whether the + reference is to Instructions ot Data (IorD), find the corresponding + physical address (pAddr) and the cache coherence algorithm (CCA) + used to resolve the reference. If the virtual address is in one of + the unmapped address spaces the physical address and the CCA are + determined directly by the virtual address. If the virtual address + is in one of the mapped address spaces then the TLB is used to + determine the physical address and access type; if the required + translation is not present in the TLB or the desired access is not + permitted the function fails and an exception is taken. + + NOTE: Normally (RAW == 0), when address translation fails, this + function raises an exception and does not return. */ + +INLINE_SIM_MAIN +(int) address_translation (SIM_DESC sd, - sim_cpu *cpu, + sim_cpu * cpu, address_word cia, address_word vAddr, int IorD, int LorS, - address_word *pAddr, + address_word * pAddr, int *CCA, int raw) { - int res = -1; /* TRUE : Assume good return */ + int res = -1; /* TRUE : Assume good return */ #ifdef DEBUG - sim_io_printf(sd,"AddressTranslation(0x%s,%s,%s,...);\n",pr_addr(vAddr),(IorD ? "isDATA" : "isINSTRUCTION"),(LorS ? "iSTORE" : "isLOAD")); + sim_io_printf (sd, "AddressTranslation(0x%s,%s,%s,...);\n", pr_addr (vAddr), (IorD ? "isDATA" : "isINSTRUCTION"), (LorS ? "iSTORE" : "isLOAD")); #endif /* Check that the address is valid for this memory model */ @@ -74,28 +350,16 @@ address_translation (SIM_DESC sd, addressess through (mostly) unchanged. */ vAddr &= 0xFFFFFFFF; - *pAddr = vAddr; /* default for isTARGET */ + *pAddr = vAddr; /* default for isTARGET */ + *CCA = Uncached; /* not used for isHOST */ + + return (res); +} /* start-sanitize-sky */ -#ifdef TARGET_SKY - if (vAddr >= 0x80000000) - { - if (vAddr < 0xa0000000) - { - *pAddr = vAddr - 0x80000000; - } - else if (vAddr < 0xc0000000) - { - *pAddr = vAddr - 0xa0000000; - } - } -#endif +#endif /* !TARGET_SKY */ /* end-sanitize-sky */ - *CCA = Uncached; /* not used for isHOST */ - - return(res); -} /* Description from page A-23 of the "MIPS IV Instruction Set" manual (revision 3.1) */ |