URL
https://opencores.org/ocsvn/or1k/or1k/trunk
Subversion Repositories or1k
[/] [or1k/] [tags/] [stable_0_2_0_rc3/] [or1ksim/] [mmu/] [dmmu.c] - Rev 456
Go to most recent revision | Compare with Previous | Blame | View Log
/* dmmu.c -- Data MMU simulation Copyright (C) 1999 Damjan Lampret, lampret@opencores.org This file is part of OpenRISC 1000 Architectural Simulator. 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ /* DMMU model (not functional yet, currently just copy of data cache). */ #include "dmmu.h" #include "abstract.h" #include "stats.h" #include "sprs.h" #include "except.h" #include "sim-config.h" extern int cont_run; /* Data MMU */ inline unsigned long dmmu_simulate_tlb(unsigned long virtaddr, int write_access) { int set, way = -1; int i; unsigned long tagaddr; unsigned long vpn, ppn; if (!(mfspr(SPR_SR) & SPR_SR_DME) || (!testsprbits(SPR_SR, SPR_SR_DME))) return virtaddr; /* Which set to check out? */ set = (virtaddr / config.dmmu.pagesize) % config.dmmu.nsets; tagaddr = (virtaddr / config.dmmu.pagesize) / config.dmmu.nsets; vpn = virtaddr / (config.dmmu.pagesize * config.dmmu.nsets); /* Scan all ways and try to find a matching way. */ for (i = 0; i < config.dmmu.nways; i++) if (((mfspr(SPR_DTLBMR_BASE(i) + set) / (config.dmmu.pagesize * config.dmmu.nsets)) == vpn) && testsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_V)) way = i; /* Did we find our tlb entry? */ if (way >= 0) { /* Yes, we did. */ dmmu_stats.loads_tlbhit++; debug(5, "DTLB hit (virtaddr=%x).\n", virtaddr); /* Test for page fault */ if (mfspr (SPR_SR) & SPR_SR_SUPV) { if ( write_access && !(mfspr (SPR_DTLBTR_BASE(way) + set) & SPR_DTLBTR_SWE) || !write_access && !(mfspr (SPR_DTLBTR_BASE(way) + set) & SPR_DTLBTR_SRE)) except_handle(EXCEPT_DPF, virtaddr); } else { if ( write_access && !(mfspr (SPR_DTLBTR_BASE(way) + set) & SPR_DTLBTR_UWE) || !write_access && !(mfspr (SPR_DTLBTR_BASE(way) + set) & SPR_DTLBTR_URE)) except_handle(EXCEPT_DPF, virtaddr); } /* Set LRUs */ for (i = 0; i < config.dmmu.nways; i++) if (testsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU)) setsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU, getsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU) - 1); setsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBMR_LRU, config.dmmu.ustates - 1); ppn = mfspr(SPR_DTLBTR_BASE(way) + set) / config.dmmu.pagesize; return (ppn * config.dmmu.pagesize) + (virtaddr % config.dmmu.pagesize); } else { /* No, we didn't. */ int minlru = config.dmmu.ustates - 1; int minway = 0; dmmu_stats.loads_tlbmiss++; #if 0 for (i = 0; i < config.dmmu.nways; i++) if (getsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU) < minlru) minway = i; setsprbits(SPR_DTLBMR_BASE(minway) + set, SPR_DTLBMR_VPN, vpn); for (i = 0; i < config.dmmu.nways; i++) if (getsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU)) setsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU, getsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU) - 1); setsprbits(SPR_DTLBMR_BASE(minway) + set, SPR_DTLBMR_LRU, config.dmmu.ustates - 1); setsprbits(SPR_DTLBTR_BASE(minway) + set, SPR_DTLBTR_PPN, vpn); /* 1 to 1 */ setsprbits(SPR_DTLBMR_BASE(minway) + set, SPR_DTLBMR_V, 1); #endif except_handle(EXCEPT_DTLBMISS, virtaddr); /* if tlb refill implemented in HW */ /* return getsprbits(SPR_DTLBTR_BASE(minway) + set, SPR_DTLBTR_PPN) * config.dmmu.pagesize + (virtaddr % config.dmmu.pagesize); */ return 0; } } unsigned long dmmu_translate(unsigned long virtaddr, int write_access) { unsigned long phyaddr = dmmu_simulate_tlb(virtaddr, write_access); /* printf("DMMU translate(%x) = %x\n", virtaddr, phyaddr);*/ return phyaddr; } void dtlb_info() { if (!testsprbits(SPR_UPR, SPR_UPR_DMP)) { printf("DMMU not implemented. Set UPR[DMP].\n"); return; } printf("Data MMU %dKB: ", config.dmmu.nsets * config.dmmu.entrysize * config.dmmu.nways / 1024); printf("%d ways, %d sets, entry size %d bytes\n", config.dmmu.nways, config.dmmu.nsets, config.dmmu.entrysize); } /* First check if virtual address is covered by DTLB and if it is: - increment DTLB read hit stats, - set 'lru' at this way to config.dmmu.ustates - 1 and decrement 'lru' of other ways unless they have reached 0, - check page access attributes and invoke DMMU page fault exception handler if necessary and if not: - increment DTLB read miss stats - find lru way and entry and invoke DTLB miss exception handler - set 'lru' with config.dmmu.ustates - 1 and decrement 'lru' of other ways unless they have reached 0 */ void dtlb_status(int start_set) { int set; int way; int end_set = config.dmmu.nsets; if (!testsprbits(SPR_UPR, SPR_UPR_DMP)) { printf("DMMU not implemented. Set UPR[DMP].\n"); return; } if ((start_set >= 0) && (start_set < end_set)) end_set = start_set + 1; else start_set = 0; printf("\nDMMU: "); /* Scan set(s) and way(s). */ for (set = start_set; set < end_set; set++) { printf("\nSet %x: ", set); for (way = 0; way < config.dmmu.nways; way++) { printf(" way %d: ", way); printf("vpn=%x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBMR_VPN)); printf("lru=%x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBMR_LRU)); printf("pl1=%x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBMR_PL1)); printf("v=%x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBMR_V)); printf("a=%x ", getsprbits(SPR_DTLBTR_BASE(way) + set, SPR_DTLBTR_A)); printf("d=%x ", getsprbits(SPR_DTLBTR_BASE(way) + set, SPR_DTLBTR_D)); printf("ure=%x ", getsprbits(SPR_DTLBTR_BASE(way) + set, SPR_DTLBTR_URE)); printf("uwe=%x ", getsprbits(SPR_DTLBTR_BASE(way) + set, SPR_DTLBTR_UWE)); printf("sre=%x ", getsprbits(SPR_DTLBTR_BASE(way) + set, SPR_DTLBTR_SRE)); printf("swe=%x ", getsprbits(SPR_DTLBTR_BASE(way) + set, SPR_DTLBTR_SWE)); printf("ppn=%x ", getsprbits(SPR_DTLBTR_BASE(way) + set, SPR_DTLBTR_PPN)); } } printf("\n"); }
Go to most recent revision | Compare with Previous | Blame | View Log