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- from Rev 73 to Rev 74
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Rev 73 → Rev 74
/trunk/or1ksim/mmu/immu.c
0,0 → 1,163
/* 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() |
{ |
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 |
*/ |
|
unsigned long itlb_status(int start_set) |
{ |
int set; |
int way; |
int end_set = ITLB_SETS; |
|
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)) |
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) && |
getsprbits(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 (getsprbits(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 (getsprbits(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; |
} |
} |
/trunk/or1ksim/mmu/immu.h
0,0 → 1,26
/* immu.h -- Instruction MMU header file |
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. */ |
|
/* more or less useless at the moment */ |
|
/* Page size (in bytes) */ |
#define PAGE_SIZE 4096 /* 4KB page size */ |
|
|
unsigned long immu_translate(unsigned long virtaddr); |