xref: /linux/arch/sparc/kernel/sun4m_smp.c (revision 9d9659b6c0ebf7dde65ebada4c67980818245913)
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 /* At each hardware IRQ, we get this called to forward IRQ reception
154  * to the next processor.  The caller must disable the IRQ level being
155  * serviced globally so that there are no double interrupts received.
156  *
157  * XXX See sparc64 irq.c.
158  */
159 void smp4m_irq_rotate(int cpu)
160 {
161 	int next = cpu_data(cpu).next;
162 
163 	if (next != cpu)
164 		set_irq_udt(next);
165 }
166 
167 static struct smp_funcall {
168 	smpfunc_t func;
169 	unsigned long arg1;
170 	unsigned long arg2;
171 	unsigned long arg3;
172 	unsigned long arg4;
173 	unsigned long arg5;
174 	unsigned long processors_in[SUN4M_NCPUS];  /* Set when ipi entered. */
175 	unsigned long processors_out[SUN4M_NCPUS]; /* Set when ipi exited. */
176 } ccall_info;
177 
178 static DEFINE_SPINLOCK(cross_call_lock);
179 
180 /* Cross calls must be serialized, at least currently. */
181 static void smp4m_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
182 			     unsigned long arg2, unsigned long arg3,
183 			     unsigned long arg4)
184 {
185 		register int ncpus = SUN4M_NCPUS;
186 		unsigned long flags;
187 
188 		spin_lock_irqsave(&cross_call_lock, flags);
189 
190 		/* Init function glue. */
191 		ccall_info.func = func;
192 		ccall_info.arg1 = arg1;
193 		ccall_info.arg2 = arg2;
194 		ccall_info.arg3 = arg3;
195 		ccall_info.arg4 = arg4;
196 		ccall_info.arg5 = 0;
197 
198 		/* Init receive/complete mapping, plus fire the IPI's off. */
199 		{
200 			register int i;
201 
202 			cpu_clear(smp_processor_id(), mask);
203 			cpus_and(mask, cpu_online_map, mask);
204 			for (i = 0; i < ncpus; i++) {
205 				if (cpu_isset(i, mask)) {
206 					ccall_info.processors_in[i] = 0;
207 					ccall_info.processors_out[i] = 0;
208 					set_cpu_int(i, IRQ_CROSS_CALL);
209 				} else {
210 					ccall_info.processors_in[i] = 1;
211 					ccall_info.processors_out[i] = 1;
212 				}
213 			}
214 		}
215 
216 		{
217 			register int i;
218 
219 			i = 0;
220 			do {
221 				if (!cpu_isset(i, mask))
222 					continue;
223 				while (!ccall_info.processors_in[i])
224 					barrier();
225 			} while (++i < ncpus);
226 
227 			i = 0;
228 			do {
229 				if (!cpu_isset(i, mask))
230 					continue;
231 				while (!ccall_info.processors_out[i])
232 					barrier();
233 			} while (++i < ncpus);
234 		}
235 		spin_unlock_irqrestore(&cross_call_lock, flags);
236 }
237 
238 /* Running cross calls. */
239 void smp4m_cross_call_irq(void)
240 {
241 	int i = smp_processor_id();
242 
243 	ccall_info.processors_in[i] = 1;
244 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
245 			ccall_info.arg4, ccall_info.arg5);
246 	ccall_info.processors_out[i] = 1;
247 }
248 
249 void smp4m_percpu_timer_interrupt(struct pt_regs *regs)
250 {
251 	struct pt_regs *old_regs;
252 	int cpu = smp_processor_id();
253 
254 	old_regs = set_irq_regs(regs);
255 
256 	sun4m_clear_profile_irq(cpu);
257 
258 	profile_tick(CPU_PROFILING);
259 
260 	if (!--prof_counter(cpu)) {
261 		int user = user_mode(regs);
262 
263 		irq_enter();
264 		update_process_times(user);
265 		irq_exit();
266 
267 		prof_counter(cpu) = prof_multiplier(cpu);
268 	}
269 	set_irq_regs(old_regs);
270 }
271 
272 static void __cpuinit smp_setup_percpu_timer(void)
273 {
274 	int cpu = smp_processor_id();
275 
276 	prof_counter(cpu) = prof_multiplier(cpu) = 1;
277 	load_profile_irq(cpu, lvl14_resolution);
278 
279 	if (cpu == boot_cpu_id)
280 		enable_pil_irq(14);
281 }
282 
283 static void __init smp4m_blackbox_id(unsigned *addr)
284 {
285 	int rd = *addr & 0x3e000000;
286 	int rs1 = rd >> 11;
287 
288 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
289 	addr[1] = 0x8130200c | rd | rs1;	/* srl reg, 0xc, reg */
290 	addr[2] = 0x80082003 | rd | rs1;	/* and reg, 3, reg */
291 }
292 
293 static void __init smp4m_blackbox_current(unsigned *addr)
294 {
295 	int rd = *addr & 0x3e000000;
296 	int rs1 = rd >> 11;
297 
298 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
299 	addr[2] = 0x8130200a | rd | rs1;	/* srl reg, 0xa, reg */
300 	addr[4] = 0x8008200c | rd | rs1;	/* and reg, 0xc, reg */
301 }
302 
303 void __init sun4m_init_smp(void)
304 {
305 	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, smp4m_blackbox_id);
306 	BTFIXUPSET_BLACKBOX(load_current, smp4m_blackbox_current);
307 	BTFIXUPSET_CALL(smp_cross_call, smp4m_cross_call, BTFIXUPCALL_NORM);
308 	BTFIXUPSET_CALL(__hard_smp_processor_id, __smp4m_processor_id, BTFIXUPCALL_NORM);
309 }
310