xref: /linux/arch/mips/kernel/smp-mt.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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 (struct pt_regs *regs)
110 {
111 	do_IRQ(MIPSCPU_INT_BASE + MIPS_CPU_IPI_RESCHED_IRQ, regs);
112 }
113 
114 static void ipi_call_dispatch (struct pt_regs *regs)
115 {
116 	do_IRQ(MIPSCPU_INT_BASE + MIPS_CPU_IPI_CALL_IRQ, regs);
117 }
118 
119 irqreturn_t ipi_resched_interrupt(int irq, void *dev_id, struct pt_regs *regs)
120 {
121 	return IRQ_HANDLED;
122 }
123 
124 irqreturn_t ipi_call_interrupt(int irq, void *dev_id, struct pt_regs *regs)
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 /*
144  * Common setup before any secondaries are started
145  * Make sure all CPU's are in a sensible state before we boot any of the
146  * secondarys
147  */
148 void plat_smp_setup(void)
149 {
150 	unsigned long val;
151 	int i, num;
152 
153 #ifdef CONFIG_MIPS_MT_FPAFF
154 	/* If we have an FPU, enroll ourselves in the FPU-full mask */
155 	if (cpu_has_fpu)
156 		cpu_set(0, mt_fpu_cpumask);
157 #endif /* CONFIG_MIPS_MT_FPAFF */
158 	if (!cpu_has_mipsmt)
159 		return;
160 
161 	/* disable MT so we can configure */
162 	dvpe();
163 	dmt();
164 
165 	mips_mt_set_cpuoptions();
166 
167 	/* Put MVPE's into 'configuration state' */
168 	set_c0_mvpcontrol(MVPCONTROL_VPC);
169 
170 	val = read_c0_mvpconf0();
171 
172 	/* we'll always have more TC's than VPE's, so loop setting everything
173 	   to a sensible state */
174 	for (i = 0, num = 0; i <= ((val & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT); i++) {
175 		settc(i);
176 
177 		/* VPE's */
178 		if (i <= ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)) {
179 
180 			/* deactivate all but vpe0 */
181 			if (i != 0) {
182 				unsigned long tmp = read_vpe_c0_vpeconf0();
183 
184 				tmp &= ~VPECONF0_VPA;
185 
186 				/* master VPE */
187 				tmp |= VPECONF0_MVP;
188 				write_vpe_c0_vpeconf0(tmp);
189 
190 				/* Record this as available CPU */
191 				cpu_set(i, phys_cpu_present_map);
192 				__cpu_number_map[i]	= ++num;
193 				__cpu_logical_map[num]	= i;
194 			}
195 
196 			/* disable multi-threading with TC's */
197 			write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
198 
199 			if (i != 0) {
200 				write_vpe_c0_status((read_c0_status() & ~(ST0_IM | ST0_IE | ST0_KSU)) | ST0_CU0);
201 
202 				/* set config to be the same as vpe0, particularly kseg0 coherency alg */
203 				write_vpe_c0_config( read_c0_config());
204 
205 				/* make sure there are no software interrupts pending */
206 				write_vpe_c0_cause(read_vpe_c0_cause() & ~(C_SW1|C_SW0));
207 
208 				/* Propagate Config7 */
209 				write_vpe_c0_config7(read_c0_config7());
210 			}
211 
212 		}
213 
214 		/* TC's */
215 
216 		if (i != 0) {
217 			unsigned long tmp;
218 
219 			/* bind a TC to each VPE, May as well put all excess TC's
220 			   on the last VPE */
221 			if ( i >= (((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT)+1) )
222 				write_tc_c0_tcbind(read_tc_c0_tcbind() | ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) );
223 			else {
224 				write_tc_c0_tcbind( read_tc_c0_tcbind() | i);
225 
226 				/* and set XTC */
227 				write_vpe_c0_vpeconf0( read_vpe_c0_vpeconf0() | (i << VPECONF0_XTC_SHIFT));
228 			}
229 
230 			tmp = read_tc_c0_tcstatus();
231 
232 			/* mark not allocated and not dynamically allocatable */
233 			tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
234 			tmp |= TCSTATUS_IXMT;		/* interrupt exempt */
235 			write_tc_c0_tcstatus(tmp);
236 
237 			write_tc_c0_tchalt(TCHALT_H);
238 		}
239 	}
240 
241 	/* Release config state */
242 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
243 
244 	/* We'll wait until starting the secondaries before starting MVPE */
245 
246 	printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num);
247 }
248 
249 void __init plat_prepare_cpus(unsigned int max_cpus)
250 {
251 	/* set up ipi interrupts */
252 	if (cpu_has_vint) {
253 		set_vi_handler (MIPS_CPU_IPI_RESCHED_IRQ, ipi_resched_dispatch);
254 		set_vi_handler (MIPS_CPU_IPI_CALL_IRQ, ipi_call_dispatch);
255 	}
256 
257 	cpu_ipi_resched_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_RESCHED_IRQ;
258 	cpu_ipi_call_irq = MIPSCPU_INT_BASE + MIPS_CPU_IPI_CALL_IRQ;
259 
260 	setup_irq(cpu_ipi_resched_irq, &irq_resched);
261 	setup_irq(cpu_ipi_call_irq, &irq_call);
262 
263 	/* need to mark IPI's as IRQ_PER_CPU */
264 	irq_desc[cpu_ipi_resched_irq].status |= IRQ_PER_CPU;
265 	irq_desc[cpu_ipi_call_irq].status |= IRQ_PER_CPU;
266 }
267 
268 /*
269  * Setup the PC, SP, and GP of a secondary processor and start it
270  * running!
271  * smp_bootstrap is the place to resume from
272  * __KSTK_TOS(idle) is apparently the stack pointer
273  * (unsigned long)idle->thread_info the gp
274  * assumes a 1:1 mapping of TC => VPE
275  */
276 void prom_boot_secondary(int cpu, struct task_struct *idle)
277 {
278 	struct thread_info *gp = task_thread_info(idle);
279 	dvpe();
280 	set_c0_mvpcontrol(MVPCONTROL_VPC);
281 
282 	settc(cpu);
283 
284 	/* restart */
285 	write_tc_c0_tcrestart((unsigned long)&smp_bootstrap);
286 
287 	/* enable the tc this vpe/cpu will be running */
288 	write_tc_c0_tcstatus((read_tc_c0_tcstatus() & ~TCSTATUS_IXMT) | TCSTATUS_A);
289 
290 	write_tc_c0_tchalt(0);
291 
292 	/* enable the VPE */
293 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
294 
295 	/* stack pointer */
296 	write_tc_gpr_sp( __KSTK_TOS(idle));
297 
298 	/* global pointer */
299 	write_tc_gpr_gp((unsigned long)gp);
300 
301 	flush_icache_range((unsigned long)gp,
302 	                   (unsigned long)(gp + sizeof(struct thread_info)));
303 
304 	/* finally out of configuration and into chaos */
305 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
306 
307 	evpe(EVPE_ENABLE);
308 }
309 
310 void prom_init_secondary(void)
311 {
312 	write_c0_status((read_c0_status() & ~ST0_IM ) |
313 	                (STATUSF_IP0 | STATUSF_IP1 | STATUSF_IP7));
314 }
315 
316 void prom_smp_finish(void)
317 {
318 	write_c0_compare(read_c0_count() + (8* mips_hpt_frequency/HZ));
319 
320 #ifdef CONFIG_MIPS_MT_FPAFF
321 	/* If we have an FPU, enroll ourselves in the FPU-full mask */
322 	if (cpu_has_fpu)
323 		cpu_set(smp_processor_id(), mt_fpu_cpumask);
324 #endif /* CONFIG_MIPS_MT_FPAFF */
325 
326 	local_irq_enable();
327 }
328 
329 void prom_cpus_done(void)
330 {
331 }
332 
333 void core_send_ipi(int cpu, unsigned int action)
334 {
335 	int i;
336 	unsigned long flags;
337 	int vpflags;
338 
339 	local_irq_save (flags);
340 
341 	vpflags = dvpe();	/* cant access the other CPU's registers whilst MVPE enabled */
342 
343 	switch (action) {
344 	case SMP_CALL_FUNCTION:
345 		i = C_SW1;
346 		break;
347 
348 	case SMP_RESCHEDULE_YOURSELF:
349 	default:
350 		i = C_SW0;
351 		break;
352 	}
353 
354 	/* 1:1 mapping of vpe and tc... */
355 	settc(cpu);
356 	write_vpe_c0_cause(read_vpe_c0_cause() | i);
357 	evpe(vpflags);
358 
359 	local_irq_restore(flags);
360 }
361