xref: /openbmc/linux/arch/mips/kernel/mips-mt.c (revision b9ccfda2)
1 /*
2  * General MIPS MT support routines, usable in AP/SP, SMVP, or SMTC kernels
3  * Copyright (C) 2005 Mips Technologies, Inc
4  */
5 
6 #include <linux/device.h>
7 #include <linux/kernel.h>
8 #include <linux/sched.h>
9 #include <linux/export.h>
10 #include <linux/interrupt.h>
11 #include <linux/security.h>
12 
13 #include <asm/cpu.h>
14 #include <asm/processor.h>
15 #include <linux/atomic.h>
16 #include <asm/hardirq.h>
17 #include <asm/mmu_context.h>
18 #include <asm/mipsmtregs.h>
19 #include <asm/r4kcache.h>
20 #include <asm/cacheflush.h>
21 
22 int vpelimit;
23 
24 static int __init maxvpes(char *str)
25 {
26 	get_option(&str, &vpelimit);
27 
28 	return 1;
29 }
30 
31 __setup("maxvpes=", maxvpes);
32 
33 int tclimit;
34 
35 static int __init maxtcs(char *str)
36 {
37 	get_option(&str, &tclimit);
38 
39 	return 1;
40 }
41 
42 __setup("maxtcs=", maxtcs);
43 
44 /*
45  * Dump new MIPS MT state for the core. Does not leave TCs halted.
46  * Takes an argument which taken to be a pre-call MVPControl value.
47  */
48 
49 void mips_mt_regdump(unsigned long mvpctl)
50 {
51 	unsigned long flags;
52 	unsigned long vpflags;
53 	unsigned long mvpconf0;
54 	int nvpe;
55 	int ntc;
56 	int i;
57 	int tc;
58 	unsigned long haltval;
59 	unsigned long tcstatval;
60 #ifdef CONFIG_MIPS_MT_SMTC
61 	void smtc_soft_dump(void);
62 #endif /* CONFIG_MIPT_MT_SMTC */
63 
64 	local_irq_save(flags);
65 	vpflags = dvpe();
66 	printk("=== MIPS MT State Dump ===\n");
67 	printk("-- Global State --\n");
68 	printk("   MVPControl Passed: %08lx\n", mvpctl);
69 	printk("   MVPControl Read: %08lx\n", vpflags);
70 	printk("   MVPConf0 : %08lx\n", (mvpconf0 = read_c0_mvpconf0()));
71 	nvpe = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
72 	ntc = ((mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
73 	printk("-- per-VPE State --\n");
74 	for (i = 0; i < nvpe; i++) {
75 		for (tc = 0; tc < ntc; tc++) {
76 			settc(tc);
77 			if ((read_tc_c0_tcbind() & TCBIND_CURVPE) == i) {
78 				printk("  VPE %d\n", i);
79 				printk("   VPEControl : %08lx\n",
80 				       read_vpe_c0_vpecontrol());
81 				printk("   VPEConf0 : %08lx\n",
82 				       read_vpe_c0_vpeconf0());
83 				printk("   VPE%d.Status : %08lx\n",
84 				       i, read_vpe_c0_status());
85 				printk("   VPE%d.EPC : %08lx %pS\n",
86 				       i, read_vpe_c0_epc(),
87 				       (void *) read_vpe_c0_epc());
88 				printk("   VPE%d.Cause : %08lx\n",
89 				       i, read_vpe_c0_cause());
90 				printk("   VPE%d.Config7 : %08lx\n",
91 				       i, read_vpe_c0_config7());
92 				break; /* Next VPE */
93 			}
94 		}
95 	}
96 	printk("-- per-TC State --\n");
97 	for (tc = 0; tc < ntc; tc++) {
98 		settc(tc);
99 		if (read_tc_c0_tcbind() == read_c0_tcbind()) {
100 			/* Are we dumping ourself?  */
101 			haltval = 0; /* Then we're not halted, and mustn't be */
102 			tcstatval = flags; /* And pre-dump TCStatus is flags */
103 			printk("  TC %d (current TC with VPE EPC above)\n", tc);
104 		} else {
105 			haltval = read_tc_c0_tchalt();
106 			write_tc_c0_tchalt(1);
107 			tcstatval = read_tc_c0_tcstatus();
108 			printk("  TC %d\n", tc);
109 		}
110 		printk("   TCStatus : %08lx\n", tcstatval);
111 		printk("   TCBind : %08lx\n", read_tc_c0_tcbind());
112 		printk("   TCRestart : %08lx %pS\n",
113 		       read_tc_c0_tcrestart(), (void *) read_tc_c0_tcrestart());
114 		printk("   TCHalt : %08lx\n", haltval);
115 		printk("   TCContext : %08lx\n", read_tc_c0_tccontext());
116 		if (!haltval)
117 			write_tc_c0_tchalt(0);
118 	}
119 #ifdef CONFIG_MIPS_MT_SMTC
120 	smtc_soft_dump();
121 #endif /* CONFIG_MIPT_MT_SMTC */
122 	printk("===========================\n");
123 	evpe(vpflags);
124 	local_irq_restore(flags);
125 }
126 
127 static int mt_opt_norps;
128 static int mt_opt_rpsctl = -1;
129 static int mt_opt_nblsu = -1;
130 static int mt_opt_forceconfig7;
131 static int mt_opt_config7 = -1;
132 
133 static int __init rps_disable(char *s)
134 {
135 	mt_opt_norps = 1;
136 	return 1;
137 }
138 __setup("norps", rps_disable);
139 
140 static int __init rpsctl_set(char *str)
141 {
142 	get_option(&str, &mt_opt_rpsctl);
143 	return 1;
144 }
145 __setup("rpsctl=", rpsctl_set);
146 
147 static int __init nblsu_set(char *str)
148 {
149 	get_option(&str, &mt_opt_nblsu);
150 	return 1;
151 }
152 __setup("nblsu=", nblsu_set);
153 
154 static int __init config7_set(char *str)
155 {
156 	get_option(&str, &mt_opt_config7);
157 	mt_opt_forceconfig7 = 1;
158 	return 1;
159 }
160 __setup("config7=", config7_set);
161 
162 /* Experimental cache flush control parameters that should go away some day */
163 int mt_protiflush;
164 int mt_protdflush;
165 int mt_n_iflushes = 1;
166 int mt_n_dflushes = 1;
167 
168 static int __init set_protiflush(char *s)
169 {
170 	mt_protiflush = 1;
171 	return 1;
172 }
173 __setup("protiflush", set_protiflush);
174 
175 static int __init set_protdflush(char *s)
176 {
177 	mt_protdflush = 1;
178 	return 1;
179 }
180 __setup("protdflush", set_protdflush);
181 
182 static int __init niflush(char *s)
183 {
184 	get_option(&s, &mt_n_iflushes);
185 	return 1;
186 }
187 __setup("niflush=", niflush);
188 
189 static int __init ndflush(char *s)
190 {
191 	get_option(&s, &mt_n_dflushes);
192 	return 1;
193 }
194 __setup("ndflush=", ndflush);
195 
196 static unsigned int itc_base;
197 
198 static int __init set_itc_base(char *str)
199 {
200 	get_option(&str, &itc_base);
201 	return 1;
202 }
203 
204 __setup("itcbase=", set_itc_base);
205 
206 void mips_mt_set_cpuoptions(void)
207 {
208 	unsigned int oconfig7 = read_c0_config7();
209 	unsigned int nconfig7 = oconfig7;
210 
211 	if (mt_opt_norps) {
212 		printk("\"norps\" option deprecated: use \"rpsctl=\"\n");
213 	}
214 	if (mt_opt_rpsctl >= 0) {
215 		printk("34K return prediction stack override set to %d.\n",
216 			mt_opt_rpsctl);
217 		if (mt_opt_rpsctl)
218 			nconfig7 |= (1 << 2);
219 		else
220 			nconfig7 &= ~(1 << 2);
221 	}
222 	if (mt_opt_nblsu >= 0) {
223 		printk("34K ALU/LSU sync override set to %d.\n", mt_opt_nblsu);
224 		if (mt_opt_nblsu)
225 			nconfig7 |= (1 << 5);
226 		else
227 			nconfig7 &= ~(1 << 5);
228 	}
229 	if (mt_opt_forceconfig7) {
230 		printk("CP0.Config7 forced to 0x%08x.\n", mt_opt_config7);
231 		nconfig7 = mt_opt_config7;
232 	}
233 	if (oconfig7 != nconfig7) {
234 		__asm__ __volatile("sync");
235 		write_c0_config7(nconfig7);
236 		ehb();
237 		printk("Config7: 0x%08x\n", read_c0_config7());
238 	}
239 
240 	/* Report Cache management debug options */
241 	if (mt_protiflush)
242 		printk("I-cache flushes single-threaded\n");
243 	if (mt_protdflush)
244 		printk("D-cache flushes single-threaded\n");
245 	if (mt_n_iflushes != 1)
246 		printk("I-Cache Flushes Repeated %d times\n", mt_n_iflushes);
247 	if (mt_n_dflushes != 1)
248 		printk("D-Cache Flushes Repeated %d times\n", mt_n_dflushes);
249 
250 	if (itc_base != 0) {
251 		/*
252 		 * Configure ITC mapping.  This code is very
253 		 * specific to the 34K core family, which uses
254 		 * a special mode bit ("ITC") in the ErrCtl
255 		 * register to enable access to ITC control
256 		 * registers via cache "tag" operations.
257 		 */
258 		unsigned long ectlval;
259 		unsigned long itcblkgrn;
260 
261 		/* ErrCtl register is known as "ecc" to Linux */
262 		ectlval = read_c0_ecc();
263 		write_c0_ecc(ectlval | (0x1 << 26));
264 		ehb();
265 #define INDEX_0 (0x80000000)
266 #define INDEX_8 (0x80000008)
267 		/* Read "cache tag" for Dcache pseudo-index 8 */
268 		cache_op(Index_Load_Tag_D, INDEX_8);
269 		ehb();
270 		itcblkgrn = read_c0_dtaglo();
271 		itcblkgrn &= 0xfffe0000;
272 		/* Set for 128 byte pitch of ITC cells */
273 		itcblkgrn |= 0x00000c00;
274 		/* Stage in Tag register */
275 		write_c0_dtaglo(itcblkgrn);
276 		ehb();
277 		/* Write out to ITU with CACHE op */
278 		cache_op(Index_Store_Tag_D, INDEX_8);
279 		/* Now set base address, and turn ITC on with 0x1 bit */
280 		write_c0_dtaglo((itc_base & 0xfffffc00) | 0x1 );
281 		ehb();
282 		/* Write out to ITU with CACHE op */
283 		cache_op(Index_Store_Tag_D, INDEX_0);
284 		write_c0_ecc(ectlval);
285 		ehb();
286 		printk("Mapped %ld ITC cells starting at 0x%08x\n",
287 			((itcblkgrn & 0x7fe00000) >> 20), itc_base);
288 	}
289 }
290 
291 /*
292  * Function to protect cache flushes from concurrent execution
293  * depends on MP software model chosen.
294  */
295 
296 void mt_cflush_lockdown(void)
297 {
298 #ifdef CONFIG_MIPS_MT_SMTC
299 	void smtc_cflush_lockdown(void);
300 
301 	smtc_cflush_lockdown();
302 #endif /* CONFIG_MIPS_MT_SMTC */
303 	/* FILL IN VSMP and AP/SP VERSIONS HERE */
304 }
305 
306 void mt_cflush_release(void)
307 {
308 #ifdef CONFIG_MIPS_MT_SMTC
309 	void smtc_cflush_release(void);
310 
311 	smtc_cflush_release();
312 #endif /* CONFIG_MIPS_MT_SMTC */
313 	/* FILL IN VSMP and AP/SP VERSIONS HERE */
314 }
315 
316 struct class *mt_class;
317 
318 static int __init mt_init(void)
319 {
320 	struct class *mtc;
321 
322 	mtc = class_create(THIS_MODULE, "mt");
323 	if (IS_ERR(mtc))
324 		return PTR_ERR(mtc);
325 
326 	mt_class = mtc;
327 
328 	return 0;
329 }
330 
331 subsys_initcall(mt_init);
332