xref: /openbmc/linux/arch/sparc/kernel/sun4m_smp.c (revision 6baa9b20)
1 /*
2  *  sun4m SMP support.
3  *
4  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
5  */
6 
7 #include <linux/interrupt.h>
8 #include <linux/profile.h>
9 #include <linux/delay.h>
10 #include <linux/cpu.h>
11 
12 #include <asm/cacheflush.h>
13 #include <asm/tlbflush.h>
14 
15 #include "irq.h"
16 #include "kernel.h"
17 
18 #define IRQ_CROSS_CALL		15
19 
20 static inline unsigned long
21 swap_ulong(volatile unsigned long *ptr, unsigned long val)
22 {
23 	__asm__ __volatile__("swap [%1], %0\n\t" :
24 			     "=&r" (val), "=&r" (ptr) :
25 			     "0" (val), "1" (ptr));
26 	return val;
27 }
28 
29 static void smp_setup_percpu_timer(void);
30 
31 void __cpuinit smp4m_callin(void)
32 {
33 	int cpuid = hard_smp_processor_id();
34 
35 	local_flush_cache_all();
36 	local_flush_tlb_all();
37 
38 	notify_cpu_starting(cpuid);
39 
40 	/* Get our local ticker going. */
41 	smp_setup_percpu_timer();
42 
43 	calibrate_delay();
44 	smp_store_cpu_info(cpuid);
45 
46 	local_flush_cache_all();
47 	local_flush_tlb_all();
48 
49 	/*
50 	 * Unblock the master CPU _only_ when the scheduler state
51 	 * of all secondary CPUs will be up-to-date, so after
52 	 * the SMP initialization the master will be just allowed
53 	 * to call the scheduler code.
54 	 */
55 	/* Allow master to continue. */
56 	swap_ulong(&cpu_callin_map[cpuid], 1);
57 
58 	/* XXX: What's up with all the flushes? */
59 	local_flush_cache_all();
60 	local_flush_tlb_all();
61 
62 	cpu_probe();
63 
64 	/* Fix idle thread fields. */
65 	__asm__ __volatile__("ld [%0], %%g6\n\t"
66 			     : : "r" (&current_set[cpuid])
67 			     : "memory" /* paranoid */);
68 
69 	/* Attach to the address space of init_task. */
70 	atomic_inc(&init_mm.mm_count);
71 	current->active_mm = &init_mm;
72 
73 	while (!cpu_isset(cpuid, smp_commenced_mask))
74 		mb();
75 
76 	local_irq_enable();
77 
78 	set_cpu_online(cpuid, true);
79 }
80 
81 /*
82  *	Cycle through the processors asking the PROM to start each one.
83  */
84 void __init smp4m_boot_cpus(void)
85 {
86 	smp_setup_percpu_timer();
87 	local_flush_cache_all();
88 }
89 
90 int __cpuinit smp4m_boot_one_cpu(int i)
91 {
92 	unsigned long *entry = &sun4m_cpu_startup;
93 	struct task_struct *p;
94 	int timeout;
95 	int cpu_node;
96 
97 	cpu_find_by_mid(i, &cpu_node);
98 
99 	/* Cook up an idler for this guy. */
100 	p = fork_idle(i);
101 	current_set[i] = task_thread_info(p);
102 	/* See trampoline.S for details... */
103 	entry += ((i - 1) * 3);
104 
105 	/*
106 	 * Initialize the contexts table
107 	 * Since the call to prom_startcpu() trashes the structure,
108 	 * we need to re-initialize it for each cpu
109 	 */
110 	smp_penguin_ctable.which_io = 0;
111 	smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
112 	smp_penguin_ctable.reg_size = 0;
113 
114 	/* whirrr, whirrr, whirrrrrrrrr... */
115 	printk(KERN_INFO "Starting CPU %d at %p\n", i, entry);
116 	local_flush_cache_all();
117 	prom_startcpu(cpu_node, &smp_penguin_ctable, 0, (char *)entry);
118 
119 	/* wheee... it's going... */
120 	for (timeout = 0; timeout < 10000; timeout++) {
121 		if (cpu_callin_map[i])
122 			break;
123 		udelay(200);
124 	}
125 
126 	if (!(cpu_callin_map[i])) {
127 		printk(KERN_ERR "Processor %d is stuck.\n", i);
128 		return -ENODEV;
129 	}
130 
131 	local_flush_cache_all();
132 	return 0;
133 }
134 
135 void __init smp4m_smp_done(void)
136 {
137 	int i, first;
138 	int *prev;
139 
140 	/* setup cpu list for irq rotation */
141 	first = 0;
142 	prev = &first;
143 	for_each_online_cpu(i) {
144 		*prev = i;
145 		prev = &cpu_data(i).next;
146 	}
147 	*prev = first;
148 	local_flush_cache_all();
149 
150 	/* Ok, they are spinning and ready to go. */
151 }
152 
153 static struct smp_funcall {
154 	smpfunc_t func;
155 	unsigned long arg1;
156 	unsigned long arg2;
157 	unsigned long arg3;
158 	unsigned long arg4;
159 	unsigned long arg5;
160 	unsigned long processors_in[SUN4M_NCPUS];  /* Set when ipi entered. */
161 	unsigned long processors_out[SUN4M_NCPUS]; /* Set when ipi exited. */
162 } ccall_info;
163 
164 static DEFINE_SPINLOCK(cross_call_lock);
165 
166 /* Cross calls must be serialized, at least currently. */
167 static void smp4m_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
168 			     unsigned long arg2, unsigned long arg3,
169 			     unsigned long arg4)
170 {
171 		register int ncpus = SUN4M_NCPUS;
172 		unsigned long flags;
173 
174 		spin_lock_irqsave(&cross_call_lock, flags);
175 
176 		/* Init function glue. */
177 		ccall_info.func = func;
178 		ccall_info.arg1 = arg1;
179 		ccall_info.arg2 = arg2;
180 		ccall_info.arg3 = arg3;
181 		ccall_info.arg4 = arg4;
182 		ccall_info.arg5 = 0;
183 
184 		/* Init receive/complete mapping, plus fire the IPI's off. */
185 		{
186 			register int i;
187 
188 			cpu_clear(smp_processor_id(), mask);
189 			cpus_and(mask, cpu_online_map, mask);
190 			for (i = 0; i < ncpus; i++) {
191 				if (cpu_isset(i, mask)) {
192 					ccall_info.processors_in[i] = 0;
193 					ccall_info.processors_out[i] = 0;
194 					set_cpu_int(i, IRQ_CROSS_CALL);
195 				} else {
196 					ccall_info.processors_in[i] = 1;
197 					ccall_info.processors_out[i] = 1;
198 				}
199 			}
200 		}
201 
202 		{
203 			register int i;
204 
205 			i = 0;
206 			do {
207 				if (!cpu_isset(i, mask))
208 					continue;
209 				while (!ccall_info.processors_in[i])
210 					barrier();
211 			} while (++i < ncpus);
212 
213 			i = 0;
214 			do {
215 				if (!cpu_isset(i, mask))
216 					continue;
217 				while (!ccall_info.processors_out[i])
218 					barrier();
219 			} while (++i < ncpus);
220 		}
221 		spin_unlock_irqrestore(&cross_call_lock, flags);
222 }
223 
224 /* Running cross calls. */
225 void smp4m_cross_call_irq(void)
226 {
227 	int i = smp_processor_id();
228 
229 	ccall_info.processors_in[i] = 1;
230 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
231 			ccall_info.arg4, ccall_info.arg5);
232 	ccall_info.processors_out[i] = 1;
233 }
234 
235 void smp4m_percpu_timer_interrupt(struct pt_regs *regs)
236 {
237 	struct pt_regs *old_regs;
238 	int cpu = smp_processor_id();
239 
240 	old_regs = set_irq_regs(regs);
241 
242 	sun4m_clear_profile_irq(cpu);
243 
244 	profile_tick(CPU_PROFILING);
245 
246 	if (!--prof_counter(cpu)) {
247 		int user = user_mode(regs);
248 
249 		irq_enter();
250 		update_process_times(user);
251 		irq_exit();
252 
253 		prof_counter(cpu) = prof_multiplier(cpu);
254 	}
255 	set_irq_regs(old_regs);
256 }
257 
258 static void __cpuinit smp_setup_percpu_timer(void)
259 {
260 	int cpu = smp_processor_id();
261 
262 	prof_counter(cpu) = prof_multiplier(cpu) = 1;
263 	load_profile_irq(cpu, lvl14_resolution);
264 
265 	if (cpu == boot_cpu_id)
266 		sun4m_unmask_profile_irq();
267 }
268 
269 static void __init smp4m_blackbox_id(unsigned *addr)
270 {
271 	int rd = *addr & 0x3e000000;
272 	int rs1 = rd >> 11;
273 
274 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
275 	addr[1] = 0x8130200c | rd | rs1;	/* srl reg, 0xc, reg */
276 	addr[2] = 0x80082003 | rd | rs1;	/* and reg, 3, reg */
277 }
278 
279 static void __init smp4m_blackbox_current(unsigned *addr)
280 {
281 	int rd = *addr & 0x3e000000;
282 	int rs1 = rd >> 11;
283 
284 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
285 	addr[2] = 0x8130200a | rd | rs1;	/* srl reg, 0xa, reg */
286 	addr[4] = 0x8008200c | rd | rs1;	/* and reg, 0xc, reg */
287 }
288 
289 void __init sun4m_init_smp(void)
290 {
291 	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, smp4m_blackbox_id);
292 	BTFIXUPSET_BLACKBOX(load_current, smp4m_blackbox_current);
293 	BTFIXUPSET_CALL(smp_cross_call, smp4m_cross_call, BTFIXUPCALL_NORM);
294 	BTFIXUPSET_CALL(__hard_smp_processor_id, __smp4m_processor_id, BTFIXUPCALL_NORM);
295 }
296