1 |
62 |
lampret |
/* dmmu.c -- Data MMU simulation
|
2 |
6 |
lampret |
Copyright (C) 1999 Damjan Lampret, lampret@opencores.org
|
3 |
|
|
|
4 |
|
|
This file is part of OpenRISC 1000 Architectural Simulator.
|
5 |
|
|
|
6 |
|
|
This program is free software; you can redistribute it and/or modify
|
7 |
|
|
it under the terms of the GNU General Public License as published by
|
8 |
|
|
the Free Software Foundation; either version 2 of the License, or
|
9 |
|
|
(at your option) any later version.
|
10 |
|
|
|
11 |
|
|
This program is distributed in the hope that it will be useful,
|
12 |
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
13 |
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
14 |
|
|
GNU General Public License for more details.
|
15 |
|
|
|
16 |
|
|
You should have received a copy of the GNU General Public License
|
17 |
|
|
along with this program; if not, write to the Free Software
|
18 |
|
|
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
|
19 |
|
|
|
20 |
|
|
/* DMMU model (not functional yet, currently just copy of data cache). */
|
21 |
|
|
|
22 |
|
|
#include "dmmu.h"
|
23 |
|
|
#include "abstract.h"
|
24 |
|
|
#include "stats.h"
|
25 |
62 |
lampret |
#include "sprs.h"
|
26 |
|
|
#include "except.h"
|
27 |
6 |
lampret |
|
28 |
62 |
lampret |
extern int cont_run;
|
29 |
|
|
|
30 |
6 |
lampret |
/* Data MMU */
|
31 |
|
|
|
32 |
|
|
unsigned long dmmu_translate(unsigned long virtaddr)
|
33 |
|
|
{
|
34 |
62 |
lampret |
unsigned long phyaddr = dmmu_simulate_tlb(virtaddr);
|
35 |
|
|
|
36 |
|
|
printf("DMMU translate(%x) = %x\n", virtaddr, phyaddr);
|
37 |
|
|
return phyaddr;
|
38 |
6 |
lampret |
}
|
39 |
|
|
|
40 |
62 |
lampret |
/* Number of DTLB sets used (power of 2, max is 256) */
|
41 |
|
|
#define DTLB_SETS 16
|
42 |
6 |
lampret |
|
43 |
62 |
lampret |
/* Entry size in bytes (8 == two singlewords) */
|
44 |
|
|
#define DTLB_ENTRY_SIZE 8
|
45 |
6 |
lampret |
|
46 |
62 |
lampret |
/* Number of DTLB ways (1, 2, 3 etc., max is 4). */
|
47 |
|
|
#define DTLB_WAYS 2
|
48 |
6 |
lampret |
|
49 |
62 |
lampret |
/* Number of usage states (2, 3, 4 etc., max is 4). */
|
50 |
|
|
#define DTLB_USTATES 2
|
51 |
6 |
lampret |
|
52 |
62 |
lampret |
/* Don't change. Defined by mask of PPN/VPN bits in TLB. */
|
53 |
|
|
#define MIN_PG_SIZE 1024
|
54 |
6 |
lampret |
|
55 |
62 |
lampret |
void dtlb_info()
|
56 |
6 |
lampret |
{
|
57 |
62 |
lampret |
printf("Data MMU %dKB: ", DTLB_SETS * DTLB_ENTRY_SIZE * DTLB_WAYS / 1024);
|
58 |
|
|
printf("%d ways, %d sets, entry size %d bytes\n", DTLB_WAYS, DTLB_SETS, DTLB_ENTRY_SIZE);
|
59 |
6 |
lampret |
}
|
60 |
|
|
|
61 |
62 |
lampret |
/* First check if virtual address is covered by DTLB and if it is:
|
62 |
|
|
- increment DTLB read hit stats,
|
63 |
|
|
- set 'lru' at this way to DTLB_USTATES - 1 and
|
64 |
6 |
lampret |
decrement 'lru' of other ways unless they have reached 0,
|
65 |
62 |
lampret |
- check page access attributes and invoke DMMU page fault exception
|
66 |
|
|
handler if necessary
|
67 |
6 |
lampret |
and if not:
|
68 |
62 |
lampret |
- increment DTLB read miss stats
|
69 |
|
|
- find lru way and entry and invoke DTLB miss exception handler
|
70 |
|
|
- set 'lru' with DTLB_USTATES - 1 and decrement 'lru' of other
|
71 |
6 |
lampret |
ways unless they have reached 0
|
72 |
|
|
*/
|
73 |
|
|
|
74 |
62 |
lampret |
unsigned long dtlb_status(int start_set)
|
75 |
6 |
lampret |
{
|
76 |
62 |
lampret |
int set;
|
77 |
|
|
int way;
|
78 |
|
|
int end_set = DTLB_SETS;
|
79 |
|
|
|
80 |
|
|
if ((start_set >= 0) && (start_set < end_set))
|
81 |
|
|
end_set = start_set + 1;
|
82 |
|
|
else
|
83 |
|
|
start_set = 0;
|
84 |
|
|
|
85 |
|
|
/* Scan set(s) and way(s). */
|
86 |
|
|
for (set = start_set; set < end_set; set++) {
|
87 |
|
|
printf("\nSet %x: ", set);
|
88 |
|
|
for (way = 0; way < DTLB_WAYS; way++) {
|
89 |
|
|
printf(" way %d: ", way);
|
90 |
|
|
printf("vpn %x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBMR_VPN));
|
91 |
|
|
printf("lru %x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBMR_LRU));
|
92 |
|
|
printf("pl1 %x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBMR_PL1));
|
93 |
|
|
printf("v %x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBMR_V));
|
94 |
|
|
printf("a %x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBTR_A));
|
95 |
|
|
printf("d %x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBTR_D));
|
96 |
|
|
printf("ure %x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBTR_URE));
|
97 |
|
|
printf("uwe %x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBTR_UWE));
|
98 |
|
|
printf("sre %x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBTR_SRE));
|
99 |
|
|
printf("swe %x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBTR_SWE));
|
100 |
|
|
printf("ppn %x ", getsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBTR_PPN));
|
101 |
|
|
if (way > 0)
|
102 |
|
|
printf("\n");
|
103 |
|
|
}
|
104 |
6 |
lampret |
}
|
105 |
62 |
lampret |
printf("\n");
|
106 |
6 |
lampret |
}
|
107 |
|
|
|
108 |
62 |
lampret |
unsigned long dmmu_simulate_tlb(unsigned long virtaddr)
|
109 |
6 |
lampret |
{
|
110 |
|
|
int set, way = -1;
|
111 |
|
|
int i;
|
112 |
|
|
unsigned long tagaddr;
|
113 |
62 |
lampret |
unsigned long vpn;
|
114 |
|
|
|
115 |
|
|
if (! (mfspr(SPR_SR) & SPR_SR_DME))
|
116 |
|
|
return virtaddr;
|
117 |
|
|
|
118 |
6 |
lampret |
/* Which set to check out? */
|
119 |
62 |
lampret |
set = (virtaddr / PAGE_SIZE) % DTLB_SETS;
|
120 |
|
|
tagaddr = (virtaddr / PAGE_SIZE) / DTLB_SETS;
|
121 |
|
|
vpn = virtaddr / MIN_PG_SIZE;
|
122 |
|
|
|
123 |
6 |
lampret |
/* Scan all ways and try to find a matching way. */
|
124 |
62 |
lampret |
for (i = 0; i < DTLB_WAYS; i++)
|
125 |
|
|
if ((getsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_VPN) == vpn) &&
|
126 |
|
|
getsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_V))
|
127 |
6 |
lampret |
way = i;
|
128 |
|
|
|
129 |
62 |
lampret |
/* Did we find our tlb entry? */
|
130 |
6 |
lampret |
if (way >= 0) { /* Yes, we did. */
|
131 |
62 |
lampret |
dmmu_stats.loads_tlbhit++;
|
132 |
|
|
debug("DTLB hit (virtaddr=%x).\n", virtaddr);
|
133 |
|
|
|
134 |
|
|
/* Set LRUs */
|
135 |
|
|
for (i = 0; i < DTLB_WAYS; i++)
|
136 |
|
|
if (getsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU))
|
137 |
|
|
setsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU, getsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU) - 1);
|
138 |
|
|
setsprbits(SPR_DTLBMR_BASE(way) + set, SPR_DTLBMR_LRU, DTLB_USTATES - 1);
|
139 |
|
|
|
140 |
|
|
return getsprbits(SPR_DTLBTR_BASE(way) + set, SPR_DTLBTR_PPN) * MIN_PG_SIZE + (virtaddr % PAGE_SIZE);
|
141 |
6 |
lampret |
}
|
142 |
|
|
else { /* No, we didn't. */
|
143 |
62 |
lampret |
int minlru = DTLB_USTATES - 1;
|
144 |
6 |
lampret |
int minway = 0;
|
145 |
62 |
lampret |
|
146 |
|
|
dmmu_stats.loads_tlbmiss++;
|
147 |
|
|
#if 0
|
148 |
|
|
for (i = 0; i < DTLB_WAYS; i++)
|
149 |
|
|
if (getsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU) < minlru)
|
150 |
6 |
lampret |
minway = i;
|
151 |
|
|
|
152 |
62 |
lampret |
setsprbits(SPR_DTLBMR_BASE(minway) + set, SPR_DTLBMR_VPN, vpn);
|
153 |
|
|
for (i = 0; i < DTLB_WAYS; i++)
|
154 |
|
|
if (getsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU))
|
155 |
|
|
setsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU, getsprbits(SPR_DTLBMR_BASE(i) + set, SPR_DTLBMR_LRU) - 1);
|
156 |
|
|
setsprbits(SPR_DTLBMR_BASE(minway) + set, SPR_DTLBMR_LRU, DTLB_USTATES - 1);
|
157 |
|
|
setsprbits(SPR_DTLBTR_BASE(minway) + set, SPR_DTLBTR_PPN, vpn); /* 1 to 1 */
|
158 |
|
|
setsprbits(SPR_DTLBMR_BASE(minway) + set, SPR_DTLBMR_V, 1);
|
159 |
|
|
#endif
|
160 |
|
|
except_handle(EXCEPT_DTLBMISS, virtaddr);
|
161 |
|
|
/* if tlb refill implemented in HW */
|
162 |
|
|
/* return getsprbits(SPR_DTLBTR_BASE(minway) + set, SPR_DTLBTR_PPN) * MIN_PG_SIZE + (virtaddr % PAGE_SIZE); */
|
163 |
|
|
return 0;
|
164 |
6 |
lampret |
}
|
165 |
|
|
}
|