xref: /linux/arch/mips/kernel/smp-mt.c (revision 1417836e81c0ab8f5a0bfeafa90d3eaa41b2a067)
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 #include <asm/mips-boards/maltaint.h>  /* This is f*cking wrong */
39 
40 #define MIPS_CPU_IPI_RESCHED_IRQ 0
41 #define MIPS_CPU_IPI_CALL_IRQ 1
42 
43 static int cpu_ipi_resched_irq, cpu_ipi_call_irq;
44 
45 #if 0
46 static void dump_mtregisters(int vpe, int tc)
47 {
48 	printk("vpe %d tc %d\n", vpe, tc);
49 
50 	settc(tc);
51 
52 	printk("  c0 status  0x%lx\n", read_vpe_c0_status());
53 	printk("  vpecontrol 0x%lx\n", read_vpe_c0_vpecontrol());
54 	printk("  vpeconf0    0x%lx\n", read_vpe_c0_vpeconf0());
55 	printk("  tcstatus 0x%lx\n", read_tc_c0_tcstatus());
56 	printk("  tcrestart 0x%lx\n", read_tc_c0_tcrestart());
57 	printk("  tcbind 0x%lx\n", read_tc_c0_tcbind());
58 	printk("  tchalt 0x%lx\n", read_tc_c0_tchalt());
59 }
60 #endif
61 
62 void __init sanitize_tlb_entries(void)
63 {
64 	int i, tlbsiz;
65 	unsigned long mvpconf0, ncpu;
66 
67 	if (!cpu_has_mipsmt)
68 		return;
69 
70 	/* Enable VPC */
71 	set_c0_mvpcontrol(MVPCONTROL_VPC);
72 
73 	back_to_back_c0_hazard();
74 
75 	/* Disable TLB sharing */
76 	clear_c0_mvpcontrol(MVPCONTROL_STLB);
77 
78 	mvpconf0 = read_c0_mvpconf0();
79 
80 	printk(KERN_INFO "MVPConf0 0x%lx TLBS %lx PTLBE %ld\n", mvpconf0,
81 		   (mvpconf0 & MVPCONF0_TLBS) >> MVPCONF0_TLBS_SHIFT,
82 			   (mvpconf0 & MVPCONF0_PTLBE) >> MVPCONF0_PTLBE_SHIFT);
83 
84 	tlbsiz = (mvpconf0 & MVPCONF0_PTLBE) >> MVPCONF0_PTLBE_SHIFT;
85 	ncpu = ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
86 
87 	printk(" tlbsiz %d ncpu %ld\n", tlbsiz, ncpu);
88 
89 	if (tlbsiz > 0) {
90 		/* share them out across the vpe's */
91 		tlbsiz /= ncpu;
92 
93 		printk(KERN_INFO "setting Config1.MMU_size to %d\n", tlbsiz);
94 
95 		for (i = 0; i < ncpu; i++) {
96 			settc(i);
97 
98 			if (i == 0)
99 				write_c0_config1((read_c0_config1() & ~(0x3f << 25)) | (tlbsiz << 25));
100 			else
101 				write_vpe_c0_config1((read_vpe_c0_config1() & ~(0x3f << 25)) |
102 						   (tlbsiz << 25));
103 		}
104 	}
105 
106 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
107 }
108 
109 static void ipi_resched_dispatch(void)
110 {
111 	do_IRQ(MIPSCPU_INT_BASE + MIPS_CPU_IPI_RESCHED_IRQ);
112 }
113 
114 static void ipi_call_dispatch(void)
115 {
116 	do_IRQ(MIPSCPU_INT_BASE + MIPS_CPU_IPI_CALL_IRQ);
117 }
118 
119 static irqreturn_t ipi_resched_interrupt(int irq, void *dev_id)
120 {
121 	return IRQ_HANDLED;
122 }
123 
124 static irqreturn_t ipi_call_interrupt(int irq, void *dev_id)
125 {
126 	smp_call_function_interrupt();
127 
128 	return IRQ_HANDLED;
129 }
130 
131 static struct irqaction irq_resched = {
132 	.handler	= ipi_resched_interrupt,
133 	.flags		= IRQF_DISABLED,
134 	.name		= "IPI_resched"
135 };
136 
137 static struct irqaction irq_call = {
138 	.handler	= ipi_call_interrupt,
139 	.flags		= IRQF_DISABLED,
140 	.name		= "IPI_call"
141 };
142 
143 static void __init smp_copy_vpe_config(void)
144 {
145 	write_vpe_c0_status(
146 		(read_c0_status() & ~(ST0_IM | ST0_IE | ST0_KSU)) | ST0_CU0);
147 
148 	/* set config to be the same as vpe0, particularly kseg0 coherency alg */
149 	write_vpe_c0_config( read_c0_config());
150 
151 	/* make sure there are no software interrupts pending */
152 	write_vpe_c0_cause(0);
153 
154 	/* Propagate Config7 */
155 	write_vpe_c0_config7(read_c0_config7());
156 
157 	write_vpe_c0_count(read_c0_count());
158 }
159 
160 static unsigned int __init smp_vpe_init(unsigned int tc, unsigned int mvpconf0,
161 	unsigned int ncpu)
162 {
163 	if (tc > ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT))
164 		return ncpu;
165 
166 	/* Deactivate all but VPE 0 */
167 	if (tc != 0) {
168 		unsigned long tmp = read_vpe_c0_vpeconf0();
169 
170 		tmp &= ~VPECONF0_VPA;
171 
172 		/* master VPE */
173 		tmp |= VPECONF0_MVP;
174 		write_vpe_c0_vpeconf0(tmp);
175 
176 		/* Record this as available CPU */
177 		cpu_set(tc, phys_cpu_present_map);
178 		__cpu_number_map[tc]	= ++ncpu;
179 		__cpu_logical_map[ncpu]	= tc;
180 	}
181 
182 	/* Disable multi-threading with TC's */
183 	write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
184 
185 	if (tc != 0)
186 		smp_copy_vpe_config();
187 
188 	return ncpu;
189 }
190 
191 static void __init smp_tc_init(unsigned int tc, unsigned int mvpconf0)
192 {
193 	unsigned long tmp;
194 
195 	if (!tc)
196 		return;
197 
198 	/* bind a TC to each VPE, May as well put all excess TC's
199 	   on the last VPE */
200 	if (tc >= (((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)+1))
201 		write_tc_c0_tcbind(read_tc_c0_tcbind() | ((mvpconf0 & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT));
202 	else {
203 		write_tc_c0_tcbind(read_tc_c0_tcbind() | tc);
204 
205 		/* and set XTC */
206 		write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | (tc << VPECONF0_XTC_SHIFT));
207 	}
208 
209 	tmp = read_tc_c0_tcstatus();
210 
211 	/* mark not allocated and not dynamically allocatable */
212 	tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
213 	tmp |= TCSTATUS_IXMT;		/* interrupt exempt */
214 	write_tc_c0_tcstatus(tmp);
215 
216 	write_tc_c0_tchalt(TCHALT_H);
217 }
218 
219 /*
220  * Common setup before any secondaries are started
221  * Make sure all CPU's are in a sensible state before we boot any of the
222  * secondarys
223  */
224 void __init plat_smp_setup(void)
225 {
226 	unsigned int mvpconf0, ntc, tc, ncpu = 0;
227 
228 #ifdef CONFIG_MIPS_MT_FPAFF
229 	/* If we have an FPU, enroll ourselves in the FPU-full mask */
230 	if (cpu_has_fpu)
231 		cpu_set(0, mt_fpu_cpumask);
232 #endif /* CONFIG_MIPS_MT_FPAFF */
233 	if (!cpu_has_mipsmt)
234 		return;
235 
236 	/* disable MT so we can configure */
237 	dvpe();
238 	dmt();
239 
240 	mips_mt_set_cpuoptions();
241 
242 	/* Put MVPE's into 'configuration state' */
243 	set_c0_mvpcontrol(MVPCONTROL_VPC);
244 
245 	mvpconf0 = read_c0_mvpconf0();
246 	ntc = (mvpconf0 & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT;
247 
248 	/* we'll always have more TC's than VPE's, so loop setting everything
249 	   to a sensible state */
250 	for (tc = 0; tc <= ntc; tc++) {
251 		settc(tc);
252 
253 		smp_tc_init(tc, mvpconf0);
254 		ncpu = smp_vpe_init(tc, mvpconf0, ncpu);
255 	}
256 
257 	/* Release config state */
258 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
259 
260 	/* We'll wait until starting the secondaries before starting MVPE */
261 
262 	printk(KERN_INFO "Detected %i available secondary CPU(s)\n", ncpu);
263 }
264 
265 void __init plat_prepare_cpus(unsigned int max_cpus)
266 {
267 	/* set up ipi interrupts */
268 	if (cpu_has_vint) {
269 		set_vi_handler(MIPS_CPU_IPI_RESCHED_IRQ, ipi_resched_dispatch);
270 		set_vi_handler(MIPS_CPU_IPI_CALL_IRQ, ipi_call_dispatch);
271 	}
272 
273 	cpu_ipi_resched_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_RESCHED_IRQ;
274 	cpu_ipi_call_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_CALL_IRQ;
275 
276 	setup_irq(cpu_ipi_resched_irq, &irq_resched);
277 	setup_irq(cpu_ipi_call_irq, &irq_call);
278 
279 	/* need to mark IPI's as IRQ_PER_CPU */
280 	irq_desc[cpu_ipi_resched_irq].status |= IRQ_PER_CPU;
281 	set_irq_handler(cpu_ipi_resched_irq, handle_percpu_irq);
282 	irq_desc[cpu_ipi_call_irq].status |= IRQ_PER_CPU;
283 	set_irq_handler(cpu_ipi_call_irq, handle_percpu_irq);
284 }
285 
286 /*
287  * Setup the PC, SP, and GP of a secondary processor and start it
288  * running!
289  * smp_bootstrap is the place to resume from
290  * __KSTK_TOS(idle) is apparently the stack pointer
291  * (unsigned long)idle->thread_info the gp
292  * assumes a 1:1 mapping of TC => VPE
293  */
294 void prom_boot_secondary(int cpu, struct task_struct *idle)
295 {
296 	struct thread_info *gp = task_thread_info(idle);
297 	dvpe();
298 	set_c0_mvpcontrol(MVPCONTROL_VPC);
299 
300 	settc(cpu);
301 
302 	/* restart */
303 	write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
304 
305 	/* enable the tc this vpe/cpu will be running */
306 	write_tc_c0_tcstatus((read_tc_c0_tcstatus() & ~TCSTATUS_IXMT) | TCSTATUS_A);
307 
308 	write_tc_c0_tchalt(0);
309 
310 	/* enable the VPE */
311 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
312 
313 	/* stack pointer */
314 	write_tc_gpr_sp( __KSTK_TOS(idle));
315 
316 	/* global pointer */
317 	write_tc_gpr_gp((unsigned long)gp);
318 
319 	flush_icache_range((unsigned long)gp,
320 	                   (unsigned long)(gp + sizeof(struct thread_info)));
321 
322 	/* finally out of configuration and into chaos */
323 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
324 
325 	evpe(EVPE_ENABLE);
326 }
327 
328 void prom_init_secondary(void)
329 {
330 	write_c0_status((read_c0_status() & ~ST0_IM ) |
331 	                (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP7));
332 }
333 
334 void prom_smp_finish(void)
335 {
336 	write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
337 
338 #ifdef CONFIG_MIPS_MT_FPAFF
339 	/* If we have an FPU, enroll ourselves in the FPU-full mask */
340 	if (cpu_has_fpu)
341 		cpu_set(smp_processor_id(), mt_fpu_cpumask);
342 #endif /* CONFIG_MIPS_MT_FPAFF */
343 
344 	local_irq_enable();
345 }
346 
347 void prom_cpus_done(void)
348 {
349 }
350 
351 void core_send_ipi(int cpu, unsigned int action)
352 {
353 	int i;
354 	unsigned long flags;
355 	int vpflags;
356 
357 	local_irq_save (flags);
358 
359 	vpflags = dvpe();	/* cant access the other CPU's registers whilst MVPE enabled */
360 
361 	switch (action) {
362 	case SMP_CALL_FUNCTION:
363 		i = C_SW1;
364 		break;
365 
366 	case SMP_RESCHEDULE_YOURSELF:
367 	default:
368 		i = C_SW0;
369 		break;
370 	}
371 
372 	/* 1:1 mapping of vpe and tc... */
373 	settc(cpu);
374 	write_vpe_c0_cause(read_vpe_c0_cause() | i);
375 	evpe(vpflags);
376 
377 	local_irq_restore(flags);
378 }
379