xref: /openbmc/linux/arch/mips/kernel/smp-mt.c (revision 64c70b1c)
1 /*
2  *  This program is free software; you can distribute it and/or modify it
3  *  under the terms of the GNU General Public License (Version 2) as
4  *  published by the Free Software Foundation.
5  *
6  *  This program is distributed in the hope it will be useful, but WITHOUT
7  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
8  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
9  *  for more details.
10  *
11  *  You should have received a copy of the GNU General Public License along
12  *  with this program; if not, write to the Free Software Foundation, Inc.,
13  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
14  *
15  * Copyright (C) 2004, 05, 06 MIPS Technologies, Inc.
16  *    Elizabeth Clarke (beth@mips.com)
17  *    Ralf Baechle (ralf@linux-mips.org)
18  * Copyright (C) 2006 Ralf Baechle (ralf@linux-mips.org)
19  */
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/cpumask.h>
23 #include <linux/interrupt.h>
24 #include <linux/compiler.h>
25 
26 #include <asm/atomic.h>
27 #include <asm/cacheflush.h>
28 #include <asm/cpu.h>
29 #include <asm/processor.h>
30 #include <asm/system.h>
31 #include <asm/hardirq.h>
32 #include <asm/mmu_context.h>
33 #include <asm/smp.h>
34 #include <asm/time.h>
35 #include <asm/mipsregs.h>
36 #include <asm/mipsmtregs.h>
37 #include <asm/mips_mt.h>
38 
39 #define MIPS_CPU_IPI_RESCHED_IRQ 0
40 #define MIPS_CPU_IPI_CALL_IRQ 1
41 
42 static int cpu_ipi_resched_irq, cpu_ipi_call_irq;
43 
44 #if 0
45 static void dump_mtregisters(int vpe, int tc)
46 {
47 	printk("vpe %d tc %d\n", vpe, tc);
48 
49 	settc(tc);
50 
51 	printk("  c0 status  0x%lx\n", read_vpe_c0_status());
52 	printk("  vpecontrol 0x%lx\n", read_vpe_c0_vpecontrol());
53 	printk("  vpeconf0    0x%lx\n", read_vpe_c0_vpeconf0());
54 	printk("  tcstatus 0x%lx\n", read_tc_c0_tcstatus());
55 	printk("  tcrestart 0x%lx\n", read_tc_c0_tcrestart());
56 	printk("  tcbind 0x%lx\n", read_tc_c0_tcbind());
57 	printk("  tchalt 0x%lx\n", read_tc_c0_tchalt());
58 }
59 #endif
60 
61 void __init sanitize_tlb_entries(void)
62 {
63 	int i, tlbsiz;
64 	unsigned long mvpconf0, ncpu;
65 
66 	if (!cpu_has_mipsmt)
67 		return;
68 
69 	/* Enable VPC */
70 	set_c0_mvpcontrol(MVPCONTROL_VPC);
71 
72 	back_to_back_c0_hazard();
73 
74 	/* Disable TLB sharing */
75 	clear_c0_mvpcontrol(MVPCONTROL_STLB);
76 
77 	mvpconf0 = read_c0_mvpconf0();
78 
79 	printk(KERN_INFO "MVPConf0 0x%lx TLBS %lx PTLBE %ld\n", mvpconf0,
80 		   (mvpconf0 & MVPCONF0_TLBS) >> MVPCONF0_TLBS_SHIFT,
81 			   (mvpconf0 & MVPCONF0_PTLBE) >> MVPCONF0_PTLBE_SHIFT);
82 
83 	tlbsiz = (mvpconf0 & MVPCONF0_PTLBE) >> MVPCONF0_PTLBE_SHIFT;
84 	ncpu = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
85 
86 	printk(" tlbsiz %d ncpu %ld\n", tlbsiz, ncpu);
87 
88 	if (tlbsiz > 0) {
89 		/* share them out across the vpe's */
90 		tlbsiz /= ncpu;
91 
92 		printk(KERN_INFO "setting Config1.MMU_size to %d\n", tlbsiz);
93 
94 		for (i = 0; i < ncpu; i++) {
95 			settc(i);
96 
97 			if (i == 0)
98 				write_c0_config1((read_c0_config1() & ~(0x3f << 25)) | (tlbsiz << 25));
99 			else
100 				write_vpe_c0_config1((read_vpe_c0_config1() & ~(0x3f << 25)) |
101 						   (tlbsiz << 25));
102 		}
103 	}
104 
105 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
106 }
107 
108 static void ipi_resched_dispatch(void)
109 {
110 	do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ);
111 }
112 
113 static void ipi_call_dispatch(void)
114 {
115 	do_IRQ(MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ);
116 }
117 
118 static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
119 {
120 	return IRQ_HANDLED;
121 }
122 
123 static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
124 {
125 	smp_call_function_interrupt();
126 
127 	return IRQ_HANDLED;
128 }
129 
130 static struct irqaction irq_resched = {
131 	.handler	= ipi_resched_interrupt,
132 	.flags		= IRQF_DISABLED|IRQF_PERCPU,
133 	.name		= "IPI_resched"
134 };
135 
136 static struct irqaction irq_call = {
137 	.handler	= ipi_call_interrupt,
138 	.flags		= IRQF_DISABLED|IRQF_PERCPU,
139 	.name		= "IPI_call"
140 };
141 
142 static void __init smp_copy_vpe_config(void)
143 {
144 	write_vpe_c0_status(
145 		(read_c0_status() & ~(ST0_IM | ST0_IE | ST0_KSU)) | ST0_CU0);
146 
147 	/* set config to be the same as vpe0, particularly kseg0 coherency alg */
148 	write_vpe_c0_config( read_c0_config());
149 
150 	/* make sure there are no software interrupts pending */
151 	write_vpe_c0_cause(0);
152 
153 	/* Propagate Config7 */
154 	write_vpe_c0_config7(read_c0_config7());
155 
156 	write_vpe_c0_count(read_c0_count());
157 }
158 
159 static unsigned int __init smp_vpe_init(unsigned int tc, unsigned int mvpconf0,
160 	unsigned int ncpu)
161 {
162 	if (tc > ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT))
163 		return ncpu;
164 
165 	/* Deactivate all but VPE 0 */
166 	if (tc != 0) {
167 		unsigned long tmp = read_vpe_c0_vpeconf0();
168 
169 		tmp &= ~VPECONF0_VPA;
170 
171 		/* master VPE */
172 		tmp |= VPECONF0_MVP;
173 		write_vpe_c0_vpeconf0(tmp);
174 
175 		/* Record this as available CPU */
176 		cpu_set(tc, phys_cpu_present_map);
177 		__cpu_number_map[tc]	= ++ncpu;
178 		__cpu_logical_map[ncpu]	= tc;
179 	}
180 
181 	/* Disable multi-threading with TC's */
182 	write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
183 
184 	if (tc != 0)
185 		smp_copy_vpe_config();
186 
187 	return ncpu;
188 }
189 
190 static void __init smp_tc_init(unsigned int tc, unsigned int mvpconf0)
191 {
192 	unsigned long tmp;
193 
194 	if (!tc)
195 		return;
196 
197 	/* bind a TC to each VPE, May as well put all excess TC's
198 	   on the last VPE */
199 	if (tc >= (((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)+1))
200 		write_tc_c0_tcbind(read_tc_c0_tcbind() | ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT));
201 	else {
202 		write_tc_c0_tcbind(read_tc_c0_tcbind() | tc);
203 
204 		/* and set XTC */
205 		write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | (tc << VPECONF0_XTC_SHIFT));
206 	}
207 
208 	tmp = read_tc_c0_tcstatus();
209 
210 	/* mark not allocated and not dynamically allocatable */
211 	tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
212 	tmp |= TCSTATUS_IXMT;		/* interrupt exempt */
213 	write_tc_c0_tcstatus(tmp);
214 
215 	write_tc_c0_tchalt(TCHALT_H);
216 }
217 
218 /*
219  * Common setup before any secondaries are started
220  * Make sure all CPU's are in a sensible state before we boot any of the
221  * secondarys
222  */
223 void __init plat_smp_setup(void)
224 {
225 	unsigned int mvpconf0, ntc, tc, ncpu = 0;
226 
227 #ifdef CONFIG_MIPS_MT_FPAFF
228 	/* If we have an FPU, enroll ourselves in the FPU-full mask */
229 	if (cpu_has_fpu)
230 		cpu_set(0, mt_fpu_cpumask);
231 #endif /* CONFIG_MIPS_MT_FPAFF */
232 	if (!cpu_has_mipsmt)
233 		return;
234 
235 	/* disable MT so we can configure */
236 	dvpe();
237 	dmt();
238 
239 	/* Put MVPE's into 'configuration state' */
240 	set_c0_mvpcontrol(MVPCONTROL_VPC);
241 
242 	mvpconf0 = read_c0_mvpconf0();
243 	ntc = (mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT;
244 
245 	/* we'll always have more TC's than VPE's, so loop setting everything
246 	   to a sensible state */
247 	for (tc = 0; tc <= ntc; tc++) {
248 		settc(tc);
249 
250 		smp_tc_init(tc, mvpconf0);
251 		ncpu = smp_vpe_init(tc, mvpconf0, ncpu);
252 	}
253 
254 	/* Release config state */
255 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
256 
257 	/* We'll wait until starting the secondaries before starting MVPE */
258 
259 	printk(KERN_INFO "Detected %i available secondary CPU(s)\n", ncpu);
260 }
261 
262 void __init plat_prepare_cpus(unsigned int max_cpus)
263 {
264 	mips_mt_set_cpuoptions();
265 
266 	/* set up ipi interrupts */
267 	if (cpu_has_vint) {
268 		set_vi_handler(MIPS_CPU_IPI_RESCHED_IRQ, ipi_resched_dispatch);
269 		set_vi_handler(MIPS_CPU_IPI_CALL_IRQ, ipi_call_dispatch);
270 	}
271 
272 	cpu_ipi_resched_irq = MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_RESCHED_IRQ;
273 	cpu_ipi_call_irq = MIPS_CPU_IRQ_BASE + MIPS_CPU_IPI_CALL_IRQ;
274 
275 	setup_irq(cpu_ipi_resched_irq, &irq_resched);
276 	setup_irq(cpu_ipi_call_irq, &irq_call);
277 
278 	set_irq_handler(cpu_ipi_resched_irq, handle_percpu_irq);
279 	set_irq_handler(cpu_ipi_call_irq, handle_percpu_irq);
280 }
281 
282 /*
283  * Setup the PC, SP, and GP of a secondary processor and start it
284  * running!
285  * smp_bootstrap is the place to resume from
286  * __KSTK_TOS(idle) is apparently the stack pointer
287  * (unsigned long)idle->thread_info the gp
288  * assumes a 1:1 mapping of TC => VPE
289  */
290 void prom_boot_secondary(int cpu, struct task_struct *idle)
291 {
292 	struct thread_info *gp = task_thread_info(idle);
293 	dvpe();
294 	set_c0_mvpcontrol(MVPCONTROL_VPC);
295 
296 	settc(cpu);
297 
298 	/* restart */
299 	write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
300 
301 	/* enable the tc this vpe/cpu will be running */
302 	write_tc_c0_tcstatus((read_tc_c0_tcstatus() & ~TCSTATUS_IXMT) | TCSTATUS_A);
303 
304 	write_tc_c0_tchalt(0);
305 
306 	/* enable the VPE */
307 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
308 
309 	/* stack pointer */
310 	write_tc_gpr_sp( __KSTK_TOS(idle));
311 
312 	/* global pointer */
313 	write_tc_gpr_gp((unsigned long)gp);
314 
315 	flush_icache_range((unsigned long)gp,
316 	                   (unsigned long)(gp + sizeof(struct thread_info)));
317 
318 	/* finally out of configuration and into chaos */
319 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
320 
321 	evpe(EVPE_ENABLE);
322 }
323 
324 void prom_init_secondary(void)
325 {
326 	/* Enable per-cpu interrupts */
327 
328 	/* This is Malta specific: IPI,performance and timer inetrrupts */
329 	write_c0_status((read_c0_status() & ~ST0_IM ) |
330 	                (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP6 | STATUSF_IP7));
331 }
332 
333 void prom_smp_finish(void)
334 {
335 	write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
336 
337 #ifdef CONFIG_MIPS_MT_FPAFF
338 	/* If we have an FPU, enroll ourselves in the FPU-full mask */
339 	if (cpu_has_fpu)
340 		cpu_set(smp_processor_id(), mt_fpu_cpumask);
341 #endif /* CONFIG_MIPS_MT_FPAFF */
342 
343 	local_irq_enable();
344 }
345 
346 void prom_cpus_done(void)
347 {
348 }
349 
350 void core_send_ipi(int cpu, unsigned int action)
351 {
352 	int i;
353 	unsigned long flags;
354 	int vpflags;
355 
356 	local_irq_save (flags);
357 
358 	vpflags = dvpe();	/* cant access the other CPU's registers whilst MVPE enabled */
359 
360 	switch (action) {
361 	case SMP_CALL_FUNCTION:
362 		i = C_SW1;
363 		break;
364 
365 	case SMP_RESCHEDULE_YOURSELF:
366 	default:
367 		i = C_SW0;
368 		break;
369 	}
370 
371 	/* 1:1 mapping of vpe and tc... */
372 	settc(cpu);
373 	write_vpe_c0_cause(read_vpe_c0_cause() | i);
374 	evpe(vpflags);
375 
376 	local_irq_restore(flags);
377 }
378