xref: /openbmc/linux/arch/sparc/kernel/sun4m_smp.c (revision 81d67439)
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_IPI_SINGLE		12
19 #define IRQ_IPI_MASK		13
20 #define IRQ_IPI_RESCHED		14
21 #define IRQ_CROSS_CALL		15
22 
23 static inline unsigned long
24 swap_ulong(volatile unsigned long *ptr, unsigned long val)
25 {
26 	__asm__ __volatile__("swap [%1], %0\n\t" :
27 			     "=&r" (val), "=&r" (ptr) :
28 			     "0" (val), "1" (ptr));
29 	return val;
30 }
31 
32 static void smp4m_ipi_init(void);
33 static void smp_setup_percpu_timer(void);
34 
35 void __cpuinit smp4m_callin(void)
36 {
37 	int cpuid = hard_smp_processor_id();
38 
39 	local_flush_cache_all();
40 	local_flush_tlb_all();
41 
42 	notify_cpu_starting(cpuid);
43 
44 	/* Get our local ticker going. */
45 	smp_setup_percpu_timer();
46 
47 	calibrate_delay();
48 	smp_store_cpu_info(cpuid);
49 
50 	local_flush_cache_all();
51 	local_flush_tlb_all();
52 
53 	/*
54 	 * Unblock the master CPU _only_ when the scheduler state
55 	 * of all secondary CPUs will be up-to-date, so after
56 	 * the SMP initialization the master will be just allowed
57 	 * to call the scheduler code.
58 	 */
59 	/* Allow master to continue. */
60 	swap_ulong(&cpu_callin_map[cpuid], 1);
61 
62 	/* XXX: What's up with all the flushes? */
63 	local_flush_cache_all();
64 	local_flush_tlb_all();
65 
66 	/* Fix idle thread fields. */
67 	__asm__ __volatile__("ld [%0], %%g6\n\t"
68 			     : : "r" (&current_set[cpuid])
69 			     : "memory" /* paranoid */);
70 
71 	/* Attach to the address space of init_task. */
72 	atomic_inc(&init_mm.mm_count);
73 	current->active_mm = &init_mm;
74 
75 	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
76 		mb();
77 
78 	local_irq_enable();
79 
80 	set_cpu_online(cpuid, true);
81 }
82 
83 /*
84  *	Cycle through the processors asking the PROM to start each one.
85  */
86 void __init smp4m_boot_cpus(void)
87 {
88 	smp4m_ipi_init();
89 	smp_setup_percpu_timer();
90 	local_flush_cache_all();
91 }
92 
93 int __cpuinit smp4m_boot_one_cpu(int i)
94 {
95 	unsigned long *entry = &sun4m_cpu_startup;
96 	struct task_struct *p;
97 	int timeout;
98 	int cpu_node;
99 
100 	cpu_find_by_mid(i, &cpu_node);
101 
102 	/* Cook up an idler for this guy. */
103 	p = fork_idle(i);
104 	current_set[i] = task_thread_info(p);
105 	/* See trampoline.S for details... */
106 	entry += ((i - 1) * 3);
107 
108 	/*
109 	 * Initialize the contexts table
110 	 * Since the call to prom_startcpu() trashes the structure,
111 	 * we need to re-initialize it for each cpu
112 	 */
113 	smp_penguin_ctable.which_io = 0;
114 	smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
115 	smp_penguin_ctable.reg_size = 0;
116 
117 	/* whirrr, whirrr, whirrrrrrrrr... */
118 	printk(KERN_INFO "Starting CPU %d at %p\n", i, entry);
119 	local_flush_cache_all();
120 	prom_startcpu(cpu_node, &smp_penguin_ctable, 0, (char *)entry);
121 
122 	/* wheee... it's going... */
123 	for (timeout = 0; timeout < 10000; timeout++) {
124 		if (cpu_callin_map[i])
125 			break;
126 		udelay(200);
127 	}
128 
129 	if (!(cpu_callin_map[i])) {
130 		printk(KERN_ERR "Processor %d is stuck.\n", i);
131 		return -ENODEV;
132 	}
133 
134 	local_flush_cache_all();
135 	return 0;
136 }
137 
138 void __init smp4m_smp_done(void)
139 {
140 	int i, first;
141 	int *prev;
142 
143 	/* setup cpu list for irq rotation */
144 	first = 0;
145 	prev = &first;
146 	for_each_online_cpu(i) {
147 		*prev = i;
148 		prev = &cpu_data(i).next;
149 	}
150 	*prev = first;
151 	local_flush_cache_all();
152 
153 	/* Ok, they are spinning and ready to go. */
154 }
155 
156 
157 /* Initialize IPIs on the SUN4M SMP machine */
158 static void __init smp4m_ipi_init(void)
159 {
160 }
161 
162 static void smp4m_ipi_resched(int cpu)
163 {
164 	set_cpu_int(cpu, IRQ_IPI_RESCHED);
165 }
166 
167 static void smp4m_ipi_single(int cpu)
168 {
169 	set_cpu_int(cpu, IRQ_IPI_SINGLE);
170 }
171 
172 static void smp4m_ipi_mask_one(int cpu)
173 {
174 	set_cpu_int(cpu, IRQ_IPI_MASK);
175 }
176 
177 static struct smp_funcall {
178 	smpfunc_t func;
179 	unsigned long arg1;
180 	unsigned long arg2;
181 	unsigned long arg3;
182 	unsigned long arg4;
183 	unsigned long arg5;
184 	unsigned long processors_in[SUN4M_NCPUS];  /* Set when ipi entered. */
185 	unsigned long processors_out[SUN4M_NCPUS]; /* Set when ipi exited. */
186 } ccall_info;
187 
188 static DEFINE_SPINLOCK(cross_call_lock);
189 
190 /* Cross calls must be serialized, at least currently. */
191 static void smp4m_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
192 			     unsigned long arg2, unsigned long arg3,
193 			     unsigned long arg4)
194 {
195 		register int ncpus = SUN4M_NCPUS;
196 		unsigned long flags;
197 
198 		spin_lock_irqsave(&cross_call_lock, flags);
199 
200 		/* Init function glue. */
201 		ccall_info.func = func;
202 		ccall_info.arg1 = arg1;
203 		ccall_info.arg2 = arg2;
204 		ccall_info.arg3 = arg3;
205 		ccall_info.arg4 = arg4;
206 		ccall_info.arg5 = 0;
207 
208 		/* Init receive/complete mapping, plus fire the IPI's off. */
209 		{
210 			register int i;
211 
212 			cpumask_clear_cpu(smp_processor_id(), &mask);
213 			cpumask_and(&mask, cpu_online_mask, &mask);
214 			for (i = 0; i < ncpus; i++) {
215 				if (cpumask_test_cpu(i, &mask)) {
216 					ccall_info.processors_in[i] = 0;
217 					ccall_info.processors_out[i] = 0;
218 					set_cpu_int(i, IRQ_CROSS_CALL);
219 				} else {
220 					ccall_info.processors_in[i] = 1;
221 					ccall_info.processors_out[i] = 1;
222 				}
223 			}
224 		}
225 
226 		{
227 			register int i;
228 
229 			i = 0;
230 			do {
231 				if (!cpumask_test_cpu(i, &mask))
232 					continue;
233 				while (!ccall_info.processors_in[i])
234 					barrier();
235 			} while (++i < ncpus);
236 
237 			i = 0;
238 			do {
239 				if (!cpumask_test_cpu(i, &mask))
240 					continue;
241 				while (!ccall_info.processors_out[i])
242 					barrier();
243 			} while (++i < ncpus);
244 		}
245 		spin_unlock_irqrestore(&cross_call_lock, flags);
246 }
247 
248 /* Running cross calls. */
249 void smp4m_cross_call_irq(void)
250 {
251 	int i = smp_processor_id();
252 
253 	ccall_info.processors_in[i] = 1;
254 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
255 			ccall_info.arg4, ccall_info.arg5);
256 	ccall_info.processors_out[i] = 1;
257 }
258 
259 void smp4m_percpu_timer_interrupt(struct pt_regs *regs)
260 {
261 	struct pt_regs *old_regs;
262 	int cpu = smp_processor_id();
263 
264 	old_regs = set_irq_regs(regs);
265 
266 	sun4m_clear_profile_irq(cpu);
267 
268 	profile_tick(CPU_PROFILING);
269 
270 	if (!--prof_counter(cpu)) {
271 		int user = user_mode(regs);
272 
273 		irq_enter();
274 		update_process_times(user);
275 		irq_exit();
276 
277 		prof_counter(cpu) = prof_multiplier(cpu);
278 	}
279 	set_irq_regs(old_regs);
280 }
281 
282 static void __cpuinit smp_setup_percpu_timer(void)
283 {
284 	int cpu = smp_processor_id();
285 
286 	prof_counter(cpu) = prof_multiplier(cpu) = 1;
287 	load_profile_irq(cpu, lvl14_resolution);
288 
289 	if (cpu == boot_cpu_id)
290 		sun4m_unmask_profile_irq();
291 }
292 
293 static void __init smp4m_blackbox_id(unsigned *addr)
294 {
295 	int rd = *addr & 0x3e000000;
296 	int rs1 = rd >> 11;
297 
298 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
299 	addr[1] = 0x8130200c | rd | rs1;	/* srl reg, 0xc, reg */
300 	addr[2] = 0x80082003 | rd | rs1;	/* and reg, 3, reg */
301 }
302 
303 static void __init smp4m_blackbox_current(unsigned *addr)
304 {
305 	int rd = *addr & 0x3e000000;
306 	int rs1 = rd >> 11;
307 
308 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
309 	addr[2] = 0x8130200a | rd | rs1;	/* srl reg, 0xa, reg */
310 	addr[4] = 0x8008200c | rd | rs1;	/* and reg, 0xc, reg */
311 }
312 
313 void __init sun4m_init_smp(void)
314 {
315 	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, smp4m_blackbox_id);
316 	BTFIXUPSET_BLACKBOX(load_current, smp4m_blackbox_current);
317 	BTFIXUPSET_CALL(smp_cross_call, smp4m_cross_call, BTFIXUPCALL_NORM);
318 	BTFIXUPSET_CALL(__hard_smp_processor_id, __smp4m_processor_id, BTFIXUPCALL_NORM);
319 	BTFIXUPSET_CALL(smp_ipi_resched, smp4m_ipi_resched, BTFIXUPCALL_NORM);
320 	BTFIXUPSET_CALL(smp_ipi_single, smp4m_ipi_single, BTFIXUPCALL_NORM);
321 	BTFIXUPSET_CALL(smp_ipi_mask_one, smp4m_ipi_mask_one, BTFIXUPCALL_NORM);
322 }
323