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[/] [or1k/] [tags/] [nog_patch_69/] [or1ksim/] [mmu/] [immu.c] - Rev 167
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/* immu.c -- Instruction 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. */ /* IMMU model (not functional yet, currently just copy of data cache). */ #include "immu.h" #include "abstract.h" #include "stats.h" #include "sprs.h" #include "except.h" extern int cont_run; /* Insn MMU */ unsigned long immu_translate(unsigned long virtaddr) { unsigned long phyaddr = immu_simulate_tlb(virtaddr); /* printf("IMMU translate(%x) = %x\n", virtaddr, phyaddr);*/ return phyaddr; } /* Number of ITLB sets used (power of 2, max is 256) */ #define ITLB_SETS 16 /* Entry size in bytes (8 == two singlewords) */ #define ITLB_ENTRY_SIZE 8 /* Number of ITLB ways (1, 2, 3 etc., max is 4). */ #define ITLB_WAYS 2 /* Number of usage states (2, 3, 4 etc., max is 4). */ #define ITLB_USTATES 2 void itlb_info() { if (!testsprbits(SPR_UPR, SPR_UPR_IMP)) { printf("IMMU not implemented. Set UPR[IMP].\n"); return; } printf("Insn MMU %dKB: ", ITLB_SETS * ITLB_ENTRY_SIZE * ITLB_WAYS / 1024); printf("%d ways, %d sets, entry size %d bytes\n", ITLB_WAYS, ITLB_SETS, ITLB_ENTRY_SIZE); } /* First check if virtual address is covered by ITLB and if it is: - increment ITLB read hit stats, - set 'lru' at this way to ITLB_USTATES - 1 and decrement 'lru' of other ways unless they have reached 0, - check page access attributes and invoke IMMU page fault exception handler if necessary and if not: - increment ITLB read miss stats - find lru way and entry and invoke ITLB miss exception handler - set 'lru' with ITLB_USTATES - 1 and decrement 'lru' of other ways unless they have reached 0 */ void itlb_status(int start_set) { int set; int way; int end_set = ITLB_SETS; if (!testsprbits(SPR_UPR, SPR_UPR_IMP)) { printf("IMMU not implemented. Set UPR[IMP].\n"); return; } if ((start_set >= 0) && (start_set < end_set)) end_set = start_set + 1; else start_set = 0; printf("\nIMMU: "); /* Scan set(s) and way(s). */ for (set = start_set; set < end_set; set++) { printf("\nSet %x: ", set); for (way = 0; way < ITLB_WAYS; way++) { printf(" way %d: ", way); printf("vpn=%x ", getsprbits(SPR_ITLBMR_BASE(way) + set, SPR_ITLBMR_VPN)); printf("lru=%x ", getsprbits(SPR_ITLBMR_BASE(way) + set, SPR_ITLBMR_LRU)); printf("pl1=%x ", getsprbits(SPR_ITLBMR_BASE(way) + set, SPR_ITLBMR_PL1)); printf("v=%x ", getsprbits(SPR_ITLBMR_BASE(way) + set, SPR_ITLBMR_V)); printf("a=%x ", getsprbits(SPR_ITLBTR_BASE(way) + set, SPR_ITLBTR_A)); printf("d=%x ", getsprbits(SPR_ITLBTR_BASE(way) + set, SPR_ITLBTR_D)); printf("ure=%x ", getsprbits(SPR_ITLBTR_BASE(way) + set, SPR_ITLBTR_URE)); printf("uwe=%x ", getsprbits(SPR_ITLBTR_BASE(way) + set, SPR_ITLBTR_UWE)); printf("sre=%x ", getsprbits(SPR_ITLBTR_BASE(way) + set, SPR_ITLBTR_SRE)); printf("swe=%x ", getsprbits(SPR_ITLBTR_BASE(way) + set, SPR_ITLBTR_SWE)); printf("ppn=%x ", getsprbits(SPR_ITLBTR_BASE(way) + set, SPR_ITLBTR_PPN)); } } printf("\n"); } unsigned long immu_simulate_tlb(unsigned long virtaddr) { int set, way = -1; int i; unsigned long tagaddr; unsigned long vpn; if (!(mfspr(SPR_SR) & SPR_SR_IME) || !(testsprbits(SPR_UPR, SPR_UPR_IMP))) return virtaddr; /* Which set to check out? */ set = (virtaddr / PAGE_SIZE) % ITLB_SETS; tagaddr = (virtaddr / PAGE_SIZE) / ITLB_SETS; vpn = virtaddr / PAGE_SIZE; /* Scan all ways and try to find a matching way. */ for (i = 0; i < ITLB_WAYS; i++) if ((getsprbits(SPR_ITLBMR_BASE(i) + set, SPR_ITLBMR_VPN) == vpn) && testsprbits(SPR_ITLBMR_BASE(i) + set, SPR_ITLBMR_V)) way = i; /* Did we find our tlb entry? */ if (way >= 0) { /* Yes, we did. */ immu_stats.fetch_tlbhit++; debug("ITLB hit (virtaddr=%x).\n", virtaddr); /* Set LRUs */ for (i = 0; i < ITLB_WAYS; i++) if (testsprbits(SPR_ITLBMR_BASE(i) + set, SPR_ITLBMR_LRU)) setsprbits(SPR_ITLBMR_BASE(i) + set, SPR_ITLBMR_LRU, getsprbits(SPR_ITLBMR_BASE(i) + set, SPR_ITLBMR_LRU) - 1); setsprbits(SPR_ITLBMR_BASE(way) + set, SPR_ITLBMR_LRU, ITLB_USTATES - 1); return getsprbits(SPR_ITLBTR_BASE(way) + set, SPR_ITLBTR_PPN) * PAGE_SIZE + (virtaddr % PAGE_SIZE); } else { /* No, we didn't. */ int minlru = ITLB_USTATES - 1; int minway = 0; immu_stats.fetch_tlbmiss++; cont_run=0; #if 0 for (i = 0; i < ITLB_WAYS; i++) if (getsprbits(SPR_ITLBMR_BASE(i) + set, SPR_ITLBMR_LRU) < minlru) minway = i; setsprbits(SPR_ITLBMR_BASE(minway) + set, SPR_ITLBMR_VPN, vpn); for (i = 0; i < ITLB_WAYS; i++) if (testsprbits(SPR_ITLBMR_BASE(i) + set, SPR_ITLBMR_LRU)) setsprbits(SPR_ITLBMR_BASE(i) + set, SPR_ITLBMR_LRU, getsprbits(SPR_ITLBMR_BASE(i) + set, SPR_ITLBMR_LRU) - 1); setsprbits(SPR_ITLBMR_BASE(minway) + set, SPR_ITLBMR_LRU, ITLB_USTATES - 1); setsprbits(SPR_ITLBTR_BASE(minway) + set, SPR_ITLBTR_PPN, vpn); /* 1 to 1 */ setsprbits(SPR_ITLBMR_BASE(minway) + set, SPR_ITLBMR_V, 1); #endif except_handle(EXCEPT_ITLBMISS, virtaddr); /* if tlb refill implemented in HW */ /* return getsprbits(SPR_ITLBTR_BASE(minway) + set, SPR_ITLBTR_PPN) * PAGE_SIZE + (virtaddr % PAGE_SIZE); */ return 0; } }
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