xref: /openbmc/linux/arch/mips/kernel/mips-mt.c (revision a44e4f3a)
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 
23 int vpelimit;
24 
25 static int __init maxvpes(char *str)
26 {
27 	get_option(&str, &vpelimit);
28 
29 	return 1;
30 }
31 
32 __setup("maxvpes=", maxvpes);
33 
34 int tclimit;
35 
36 static int __init maxtcs(char *str)
37 {
38 	get_option(&str, &tclimit);
39 
40 	return 1;
41 }
42 
43 __setup("maxtcs=", maxtcs);
44 
45 /*
46  * Dump new MIPS MT state for the core. Does not leave TCs halted.
47  * Takes an argument which taken to be a pre-call MVPControl value.
48  */
49 
50 void mips_mt_regdump(unsigned long mvpctl)
51 {
52 	unsigned long flags;
53 	unsigned long vpflags;
54 	unsigned long mvpconf0;
55 	int nvpe;
56 	int ntc;
57 	int i;
58 	int tc;
59 	unsigned long haltval;
60 	unsigned long tcstatval;
61 
62 	local_irq_save(flags);
63 	vpflags = dvpe();
64 	printk("=== MIPS MT State Dump ===\n");
65 	printk("-- Global State --\n");
66 	printk("   MVPControl Passed: %08lx\n", mvpctl);
67 	printk("   MVPControl Read: %08lx\n", vpflags);
68 	printk("   MVPConf0 : %08lx\n", (mvpconf0 = read_c0_mvpconf0()));
69 	nvpe = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
70 	ntc = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
71 	printk("-- per-VPE State --\n");
72 	for (i = 0; i < nvpe; i++) {
73 		for (tc = 0; tc < ntc; tc++) {
74 			settc(tc);
75 			if ((read_tc_c0_tcbind() & TCBIND_CURVPE) == i) {
76 				printk("  VPE %d\n", i);
77 				printk("   VPEControl : %08lx\n",
78 				       read_vpe_c0_vpecontrol());
79 				printk("   VPEConf0 : %08lx\n",
80 				       read_vpe_c0_vpeconf0());
81 				printk("   VPE%d.Status : %08lx\n",
82 				       i, read_vpe_c0_status());
83 				printk("   VPE%d.EPC : %08lx %pS\n",
84 				       i, read_vpe_c0_epc(),
85 				       (void *) read_vpe_c0_epc());
86 				printk("   VPE%d.Cause : %08lx\n",
87 				       i, read_vpe_c0_cause());
88 				printk("   VPE%d.Config7 : %08lx\n",
89 				       i, read_vpe_c0_config7());
90 				break; /* Next VPE */
91 			}
92 		}
93 	}
94 	printk("-- per-TC State --\n");
95 	for (tc = 0; tc < ntc; tc++) {
96 		settc(tc);
97 		if (read_tc_c0_tcbind() == read_c0_tcbind()) {
98 			/* Are we dumping ourself?  */
99 			haltval = 0; /* Then we're not halted, and mustn't be */
100 			tcstatval = flags; /* And pre-dump TCStatus is flags */
101 			printk("  TC %d (current TC with VPE EPC above)\n", tc);
102 		} else {
103 			haltval = read_tc_c0_tchalt();
104 			write_tc_c0_tchalt(1);
105 			tcstatval = read_tc_c0_tcstatus();
106 			printk("  TC %d\n", tc);
107 		}
108 		printk("   TCStatus : %08lx\n", tcstatval);
109 		printk("   TCBind : %08lx\n", read_tc_c0_tcbind());
110 		printk("   TCRestart : %08lx %pS\n",
111 		       read_tc_c0_tcrestart(), (void *) read_tc_c0_tcrestart());
112 		printk("   TCHalt : %08lx\n", haltval);
113 		printk("   TCContext : %08lx\n", read_tc_c0_tccontext());
114 		if (!haltval)
115 			write_tc_c0_tchalt(0);
116 	}
117 	printk("===========================\n");
118 	evpe(vpflags);
119 	local_irq_restore(flags);
120 }
121 
122 static int mt_opt_rpsctl = -1;
123 static int mt_opt_nblsu = -1;
124 static int mt_opt_forceconfig7;
125 static int mt_opt_config7 = -1;
126 
127 static int __init rpsctl_set(char *str)
128 {
129 	get_option(&str, &mt_opt_rpsctl);
130 	return 1;
131 }
132 __setup("rpsctl=", rpsctl_set);
133 
134 static int __init nblsu_set(char *str)
135 {
136 	get_option(&str, &mt_opt_nblsu);
137 	return 1;
138 }
139 __setup("nblsu=", nblsu_set);
140 
141 static int __init config7_set(char *str)
142 {
143 	get_option(&str, &mt_opt_config7);
144 	mt_opt_forceconfig7 = 1;
145 	return 1;
146 }
147 __setup("config7=", config7_set);
148 
149 static unsigned int itc_base;
150 
151 static int __init set_itc_base(char *str)
152 {
153 	get_option(&str, &itc_base);
154 	return 1;
155 }
156 
157 __setup("itcbase=", set_itc_base);
158 
159 void mips_mt_set_cpuoptions(void)
160 {
161 	unsigned int oconfig7 = read_c0_config7();
162 	unsigned int nconfig7 = oconfig7;
163 
164 	if (mt_opt_rpsctl >= 0) {
165 		printk("34K return prediction stack override set to %d.\n",
166 			mt_opt_rpsctl);
167 		if (mt_opt_rpsctl)
168 			nconfig7 |= (1 << 2);
169 		else
170 			nconfig7 &= ~(1 << 2);
171 	}
172 	if (mt_opt_nblsu >= 0) {
173 		printk("34K ALU/LSU sync override set to %d.\n", mt_opt_nblsu);
174 		if (mt_opt_nblsu)
175 			nconfig7 |= (1 << 5);
176 		else
177 			nconfig7 &= ~(1 << 5);
178 	}
179 	if (mt_opt_forceconfig7) {
180 		printk("CP0.Config7 forced to 0x%08x.\n", mt_opt_config7);
181 		nconfig7 = mt_opt_config7;
182 	}
183 	if (oconfig7 != nconfig7) {
184 		__asm__ __volatile("sync");
185 		write_c0_config7(nconfig7);
186 		ehb();
187 		printk("Config7: 0x%08x\n", read_c0_config7());
188 	}
189 
190 	if (itc_base != 0) {
191 		/*
192 		 * Configure ITC mapping.  This code is very
193 		 * specific to the 34K core family, which uses
194 		 * a special mode bit ("ITC") in the ErrCtl
195 		 * register to enable access to ITC control
196 		 * registers via cache "tag" operations.
197 		 */
198 		unsigned long ectlval;
199 		unsigned long itcblkgrn;
200 
201 		/* ErrCtl register is known as "ecc" to Linux */
202 		ectlval = read_c0_ecc();
203 		write_c0_ecc(ectlval | (0x1 << 26));
204 		ehb();
205 #define INDEX_0 (0x80000000)
206 #define INDEX_8 (0x80000008)
207 		/* Read "cache tag" for Dcache pseudo-index 8 */
208 		cache_op(Index_Load_Tag_D, INDEX_8);
209 		ehb();
210 		itcblkgrn = read_c0_dtaglo();
211 		itcblkgrn &= 0xfffe0000;
212 		/* Set for 128 byte pitch of ITC cells */
213 		itcblkgrn |= 0x00000c00;
214 		/* Stage in Tag register */
215 		write_c0_dtaglo(itcblkgrn);
216 		ehb();
217 		/* Write out to ITU with CACHE op */
218 		cache_op(Index_Store_Tag_D, INDEX_8);
219 		/* Now set base address, and turn ITC on with 0x1 bit */
220 		write_c0_dtaglo((itc_base & 0xfffffc00) | 0x1 );
221 		ehb();
222 		/* Write out to ITU with CACHE op */
223 		cache_op(Index_Store_Tag_D, INDEX_0);
224 		write_c0_ecc(ectlval);
225 		ehb();
226 		printk("Mapped %ld ITC cells starting at 0x%08x\n",
227 			((itcblkgrn & 0x7fe00000) >> 20), itc_base);
228 	}
229 }
230 
231 struct class *mt_class;
232 
233 static int __init mt_init(void)
234 {
235 	struct class *mtc;
236 
237 	mtc = class_create(THIS_MODULE, "mt");
238 	if (IS_ERR(mtc))
239 		return PTR_ERR(mtc);
240 
241 	mt_class = mtc;
242 
243 	return 0;
244 }
245 
246 subsys_initcall(mt_init);
247