1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * General MIPS MT support routines, usable in AP/SP and SMVP.
4 * Copyright (C) 2005 Mips Technologies, Inc
5 */
6
7 #include <linux/device.h>
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
10 #include <linux/export.h>
11 #include <linux/interrupt.h>
12 #include <linux/security.h>
13
14 #include <asm/cpu.h>
15 #include <asm/processor.h>
16 #include <linux/atomic.h>
17 #include <asm/hardirq.h>
18 #include <asm/mmu_context.h>
19 #include <asm/mipsmtregs.h>
20 #include <asm/r4kcache.h>
21 #include <asm/cacheflush.h>
22 #include <asm/mips_mt.h>
23
24 int vpelimit;
25
maxvpes(char * str)26 static int __init maxvpes(char *str)
27 {
28 get_option(&str, &vpelimit);
29
30 return 1;
31 }
32
33 __setup("maxvpes=", maxvpes);
34
35 int tclimit;
36
maxtcs(char * str)37 static int __init maxtcs(char *str)
38 {
39 get_option(&str, &tclimit);
40
41 return 1;
42 }
43
44 __setup("maxtcs=", maxtcs);
45
46 static int mt_opt_rpsctl = -1;
47 static int mt_opt_nblsu = -1;
48 static int mt_opt_forceconfig7;
49 static int mt_opt_config7 = -1;
50
rpsctl_set(char * str)51 static int __init rpsctl_set(char *str)
52 {
53 get_option(&str, &mt_opt_rpsctl);
54 return 1;
55 }
56 __setup("rpsctl=", rpsctl_set);
57
nblsu_set(char * str)58 static int __init nblsu_set(char *str)
59 {
60 get_option(&str, &mt_opt_nblsu);
61 return 1;
62 }
63 __setup("nblsu=", nblsu_set);
64
config7_set(char * str)65 static int __init config7_set(char *str)
66 {
67 get_option(&str, &mt_opt_config7);
68 mt_opt_forceconfig7 = 1;
69 return 1;
70 }
71 __setup("config7=", config7_set);
72
73 static unsigned int itc_base;
74
set_itc_base(char * str)75 static int __init set_itc_base(char *str)
76 {
77 get_option(&str, &itc_base);
78 return 1;
79 }
80
81 __setup("itcbase=", set_itc_base);
82
mips_mt_set_cpuoptions(void)83 void mips_mt_set_cpuoptions(void)
84 {
85 unsigned int oconfig7 = read_c0_config7();
86 unsigned int nconfig7 = oconfig7;
87
88 if (mt_opt_rpsctl >= 0) {
89 printk("34K return prediction stack override set to %d.\n",
90 mt_opt_rpsctl);
91 if (mt_opt_rpsctl)
92 nconfig7 |= (1 << 2);
93 else
94 nconfig7 &= ~(1 << 2);
95 }
96 if (mt_opt_nblsu >= 0) {
97 printk("34K ALU/LSU sync override set to %d.\n", mt_opt_nblsu);
98 if (mt_opt_nblsu)
99 nconfig7 |= (1 << 5);
100 else
101 nconfig7 &= ~(1 << 5);
102 }
103 if (mt_opt_forceconfig7) {
104 printk("CP0.Config7 forced to 0x%08x.\n", mt_opt_config7);
105 nconfig7 = mt_opt_config7;
106 }
107 if (oconfig7 != nconfig7) {
108 __asm__ __volatile("sync");
109 write_c0_config7(nconfig7);
110 ehb();
111 printk("Config7: 0x%08x\n", read_c0_config7());
112 }
113
114 if (itc_base != 0) {
115 /*
116 * Configure ITC mapping. This code is very
117 * specific to the 34K core family, which uses
118 * a special mode bit ("ITC") in the ErrCtl
119 * register to enable access to ITC control
120 * registers via cache "tag" operations.
121 */
122 unsigned long ectlval;
123 unsigned long itcblkgrn;
124
125 /* ErrCtl register is known as "ecc" to Linux */
126 ectlval = read_c0_ecc();
127 write_c0_ecc(ectlval | (0x1 << 26));
128 ehb();
129 #define INDEX_0 (0x80000000)
130 #define INDEX_8 (0x80000008)
131 /* Read "cache tag" for Dcache pseudo-index 8 */
132 cache_op(Index_Load_Tag_D, INDEX_8);
133 ehb();
134 itcblkgrn = read_c0_dtaglo();
135 itcblkgrn &= 0xfffe0000;
136 /* Set for 128 byte pitch of ITC cells */
137 itcblkgrn |= 0x00000c00;
138 /* Stage in Tag register */
139 write_c0_dtaglo(itcblkgrn);
140 ehb();
141 /* Write out to ITU with CACHE op */
142 cache_op(Index_Store_Tag_D, INDEX_8);
143 /* Now set base address, and turn ITC on with 0x1 bit */
144 write_c0_dtaglo((itc_base & 0xfffffc00) | 0x1 );
145 ehb();
146 /* Write out to ITU with CACHE op */
147 cache_op(Index_Store_Tag_D, INDEX_0);
148 write_c0_ecc(ectlval);
149 ehb();
150 printk("Mapped %ld ITC cells starting at 0x%08x\n",
151 ((itcblkgrn & 0x7fe00000) >> 20), itc_base);
152 }
153 }
154
155 const struct class mt_class = {
156 .name = "mt",
157 };
158
mips_mt_init(void)159 static int __init mips_mt_init(void)
160 {
161 return class_register(&mt_class);
162 }
163
164 subsys_initcall(mips_mt_init);
165