xref: /linux/arch/mips/kernel/mips-mt.c (revision be239684b18e1cdcafcf8c7face4a2f562c745ad)
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 
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 
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 /*
47  * Dump new MIPS MT state for the core. Does not leave TCs halted.
48  * Takes an argument which taken to be a pre-call MVPControl value.
49  */
50 
51 void mips_mt_regdump(unsigned long mvpctl)
52 {
53 	unsigned long flags;
54 	unsigned long vpflags;
55 	unsigned long mvpconf0;
56 	int nvpe;
57 	int ntc;
58 	int i;
59 	int tc;
60 	unsigned long haltval;
61 	unsigned long tcstatval;
62 
63 	local_irq_save(flags);
64 	vpflags = dvpe();
65 	printk("=== MIPS MT State Dump ===\n");
66 	printk("-- Global State --\n");
67 	printk("   MVPControl Passed: %08lx\n", mvpctl);
68 	printk("   MVPControl Read: %08lx\n", vpflags);
69 	printk("   MVPConf0 : %08lx\n", (mvpconf0 = read_c0_mvpconf0()));
70 	nvpe = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
71 	ntc = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
72 	printk("-- per-VPE State --\n");
73 	for (i = 0; i < nvpe; i++) {
74 		for (tc = 0; tc < ntc; tc++) {
75 			settc(tc);
76 			if ((read_tc_c0_tcbind() & TCBIND_CURVPE) == i) {
77 				printk("  VPE %d\n", i);
78 				printk("   VPEControl : %08lx\n",
79 				       read_vpe_c0_vpecontrol());
80 				printk("   VPEConf0 : %08lx\n",
81 				       read_vpe_c0_vpeconf0());
82 				printk("   VPE%d.Status : %08lx\n",
83 				       i, read_vpe_c0_status());
84 				printk("   VPE%d.EPC : %08lx %pS\n",
85 				       i, read_vpe_c0_epc(),
86 				       (void *) read_vpe_c0_epc());
87 				printk("   VPE%d.Cause : %08lx\n",
88 				       i, read_vpe_c0_cause());
89 				printk("   VPE%d.Config7 : %08lx\n",
90 				       i, read_vpe_c0_config7());
91 				break; /* Next VPE */
92 			}
93 		}
94 	}
95 	printk("-- per-TC State --\n");
96 	for (tc = 0; tc < ntc; tc++) {
97 		settc(tc);
98 		if (read_tc_c0_tcbind() == read_c0_tcbind()) {
99 			/* Are we dumping ourself?  */
100 			haltval = 0; /* Then we're not halted, and mustn't be */
101 			tcstatval = flags; /* And pre-dump TCStatus is flags */
102 			printk("  TC %d (current TC with VPE EPC above)\n", tc);
103 		} else {
104 			haltval = read_tc_c0_tchalt();
105 			write_tc_c0_tchalt(1);
106 			tcstatval = read_tc_c0_tcstatus();
107 			printk("  TC %d\n", tc);
108 		}
109 		printk("   TCStatus : %08lx\n", tcstatval);
110 		printk("   TCBind : %08lx\n", read_tc_c0_tcbind());
111 		printk("   TCRestart : %08lx %pS\n",
112 		       read_tc_c0_tcrestart(), (void *) read_tc_c0_tcrestart());
113 		printk("   TCHalt : %08lx\n", haltval);
114 		printk("   TCContext : %08lx\n", read_tc_c0_tccontext());
115 		if (!haltval)
116 			write_tc_c0_tchalt(0);
117 	}
118 	printk("===========================\n");
119 	evpe(vpflags);
120 	local_irq_restore(flags);
121 }
122 
123 static int mt_opt_rpsctl = -1;
124 static int mt_opt_nblsu = -1;
125 static int mt_opt_forceconfig7;
126 static int mt_opt_config7 = -1;
127 
128 static int __init rpsctl_set(char *str)
129 {
130 	get_option(&str, &mt_opt_rpsctl);
131 	return 1;
132 }
133 __setup("rpsctl=", rpsctl_set);
134 
135 static int __init nblsu_set(char *str)
136 {
137 	get_option(&str, &mt_opt_nblsu);
138 	return 1;
139 }
140 __setup("nblsu=", nblsu_set);
141 
142 static int __init config7_set(char *str)
143 {
144 	get_option(&str, &mt_opt_config7);
145 	mt_opt_forceconfig7 = 1;
146 	return 1;
147 }
148 __setup("config7=", config7_set);
149 
150 static unsigned int itc_base;
151 
152 static int __init set_itc_base(char *str)
153 {
154 	get_option(&str, &itc_base);
155 	return 1;
156 }
157 
158 __setup("itcbase=", set_itc_base);
159 
160 void mips_mt_set_cpuoptions(void)
161 {
162 	unsigned int oconfig7 = read_c0_config7();
163 	unsigned int nconfig7 = oconfig7;
164 
165 	if (mt_opt_rpsctl >= 0) {
166 		printk("34K return prediction stack override set to %d.\n",
167 			mt_opt_rpsctl);
168 		if (mt_opt_rpsctl)
169 			nconfig7 |= (1 << 2);
170 		else
171 			nconfig7 &= ~(1 << 2);
172 	}
173 	if (mt_opt_nblsu >= 0) {
174 		printk("34K ALU/LSU sync override set to %d.\n", mt_opt_nblsu);
175 		if (mt_opt_nblsu)
176 			nconfig7 |= (1 << 5);
177 		else
178 			nconfig7 &= ~(1 << 5);
179 	}
180 	if (mt_opt_forceconfig7) {
181 		printk("CP0.Config7 forced to 0x%08x.\n", mt_opt_config7);
182 		nconfig7 = mt_opt_config7;
183 	}
184 	if (oconfig7 != nconfig7) {
185 		__asm__ __volatile("sync");
186 		write_c0_config7(nconfig7);
187 		ehb();
188 		printk("Config7: 0x%08x\n", read_c0_config7());
189 	}
190 
191 	if (itc_base != 0) {
192 		/*
193 		 * Configure ITC mapping.  This code is very
194 		 * specific to the 34K core family, which uses
195 		 * a special mode bit ("ITC") in the ErrCtl
196 		 * register to enable access to ITC control
197 		 * registers via cache "tag" operations.
198 		 */
199 		unsigned long ectlval;
200 		unsigned long itcblkgrn;
201 
202 		/* ErrCtl register is known as "ecc" to Linux */
203 		ectlval = read_c0_ecc();
204 		write_c0_ecc(ectlval | (0x1 << 26));
205 		ehb();
206 #define INDEX_0 (0x80000000)
207 #define INDEX_8 (0x80000008)
208 		/* Read "cache tag" for Dcache pseudo-index 8 */
209 		cache_op(Index_Load_Tag_D, INDEX_8);
210 		ehb();
211 		itcblkgrn = read_c0_dtaglo();
212 		itcblkgrn &= 0xfffe0000;
213 		/* Set for 128 byte pitch of ITC cells */
214 		itcblkgrn |= 0x00000c00;
215 		/* Stage in Tag register */
216 		write_c0_dtaglo(itcblkgrn);
217 		ehb();
218 		/* Write out to ITU with CACHE op */
219 		cache_op(Index_Store_Tag_D, INDEX_8);
220 		/* Now set base address, and turn ITC on with 0x1 bit */
221 		write_c0_dtaglo((itc_base & 0xfffffc00) | 0x1 );
222 		ehb();
223 		/* Write out to ITU with CACHE op */
224 		cache_op(Index_Store_Tag_D, INDEX_0);
225 		write_c0_ecc(ectlval);
226 		ehb();
227 		printk("Mapped %ld ITC cells starting at 0x%08x\n",
228 			((itcblkgrn & 0x7fe00000) >> 20), itc_base);
229 	}
230 }
231 
232 struct class *mt_class;
233 
234 static int __init mips_mt_init(void)
235 {
236 	struct class *mtc;
237 
238 	mtc = class_create("mt");
239 	if (IS_ERR(mtc))
240 		return PTR_ERR(mtc);
241 
242 	mt_class = mtc;
243 
244 	return 0;
245 }
246 
247 subsys_initcall(mips_mt_init);
248