xref: /openbmc/linux/arch/sparc/kernel/sun4m_smp.c (revision 1fa6ac37)
1 /* sun4m_smp.c: Sparc SUN4M SMP support.
2  *
3  * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
4  */
5 
6 #include <asm/head.h>
7 
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
10 #include <linux/threads.h>
11 #include <linux/smp.h>
12 #include <linux/interrupt.h>
13 #include <linux/kernel_stat.h>
14 #include <linux/init.h>
15 #include <linux/spinlock.h>
16 #include <linux/mm.h>
17 #include <linux/swap.h>
18 #include <linux/profile.h>
19 #include <linux/delay.h>
20 #include <linux/cpu.h>
21 
22 #include <asm/cacheflush.h>
23 #include <asm/tlbflush.h>
24 #include <asm/irq_regs.h>
25 
26 #include <asm/ptrace.h>
27 #include <asm/atomic.h>
28 
29 #include <asm/irq.h>
30 #include <asm/page.h>
31 #include <asm/pgalloc.h>
32 #include <asm/pgtable.h>
33 #include <asm/oplib.h>
34 #include <asm/cpudata.h>
35 
36 #include "irq.h"
37 
38 #define IRQ_CROSS_CALL		15
39 
40 extern ctxd_t *srmmu_ctx_table_phys;
41 
42 extern volatile unsigned long cpu_callin_map[NR_CPUS];
43 extern unsigned char boot_cpu_id;
44 
45 extern cpumask_t smp_commenced_mask;
46 
47 extern int __smp4m_processor_id(void);
48 
49 /*#define SMP_DEBUG*/
50 
51 #ifdef SMP_DEBUG
52 #define SMP_PRINTK(x)	printk x
53 #else
54 #define SMP_PRINTK(x)
55 #endif
56 
57 static inline unsigned long
58 swap_ulong(volatile unsigned long *ptr, unsigned long val)
59 {
60 	__asm__ __volatile__("swap [%1], %0\n\t" :
61 			     "=&r" (val), "=&r" (ptr) :
62 			     "0" (val), "1" (ptr));
63 	return val;
64 }
65 
66 static void smp_setup_percpu_timer(void);
67 extern void cpu_probe(void);
68 
69 void __cpuinit smp4m_callin(void)
70 {
71 	int cpuid = hard_smp_processor_id();
72 
73 	local_flush_cache_all();
74 	local_flush_tlb_all();
75 
76 	notify_cpu_starting(cpuid);
77 
78 	/* Get our local ticker going. */
79 	smp_setup_percpu_timer();
80 
81 	calibrate_delay();
82 	smp_store_cpu_info(cpuid);
83 
84 	local_flush_cache_all();
85 	local_flush_tlb_all();
86 
87 	/*
88 	 * Unblock the master CPU _only_ when the scheduler state
89 	 * of all secondary CPUs will be up-to-date, so after
90 	 * the SMP initialization the master will be just allowed
91 	 * to call the scheduler code.
92 	 */
93 	/* Allow master to continue. */
94 	swap_ulong(&cpu_callin_map[cpuid], 1);
95 
96 	/* XXX: What's up with all the flushes? */
97 	local_flush_cache_all();
98 	local_flush_tlb_all();
99 
100 	cpu_probe();
101 
102 	/* Fix idle thread fields. */
103 	__asm__ __volatile__("ld [%0], %%g6\n\t"
104 			     : : "r" (&current_set[cpuid])
105 			     : "memory" /* paranoid */);
106 
107 	/* Attach to the address space of init_task. */
108 	atomic_inc(&init_mm.mm_count);
109 	current->active_mm = &init_mm;
110 
111 	while (!cpu_isset(cpuid, smp_commenced_mask))
112 		mb();
113 
114 	local_irq_enable();
115 
116 	set_cpu_online(cpuid, true);
117 }
118 
119 /*
120  *	Cycle through the processors asking the PROM to start each one.
121  */
122 
123 extern struct linux_prom_registers smp_penguin_ctable;
124 
125 void __init smp4m_boot_cpus(void)
126 {
127 	smp_setup_percpu_timer();
128 	local_flush_cache_all();
129 }
130 
131 int __cpuinit smp4m_boot_one_cpu(int i)
132 {
133 	extern unsigned long sun4m_cpu_startup;
134 	unsigned long *entry = &sun4m_cpu_startup;
135 	struct task_struct *p;
136 	int timeout;
137 	int cpu_node;
138 
139 	cpu_find_by_mid(i, &cpu_node);
140 
141 	/* Cook up an idler for this guy. */
142 	p = fork_idle(i);
143 	current_set[i] = task_thread_info(p);
144 	/* See trampoline.S for details... */
145 	entry += ((i-1) * 3);
146 
147 	/*
148 	 * Initialize the contexts table
149 	 * Since the call to prom_startcpu() trashes the structure,
150 	 * we need to re-initialize it for each cpu
151 	 */
152 	smp_penguin_ctable.which_io = 0;
153 	smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
154 	smp_penguin_ctable.reg_size = 0;
155 
156 	/* whirrr, whirrr, whirrrrrrrrr... */
157 	printk("Starting CPU %d at %p\n", i, entry);
158 	local_flush_cache_all();
159 	prom_startcpu(cpu_node,
160 		      &smp_penguin_ctable, 0, (char *)entry);
161 
162 	/* wheee... it's going... */
163 	for(timeout = 0; timeout < 10000; timeout++) {
164 		if(cpu_callin_map[i])
165 			break;
166 		udelay(200);
167 	}
168 
169 	if (!(cpu_callin_map[i])) {
170 		printk("Processor %d is stuck.\n", i);
171 		return -ENODEV;
172 	}
173 
174 	local_flush_cache_all();
175 	return 0;
176 }
177 
178 void __init smp4m_smp_done(void)
179 {
180 	int i, first;
181 	int *prev;
182 
183 	/* setup cpu list for irq rotation */
184 	first = 0;
185 	prev = &first;
186 	for_each_online_cpu(i) {
187 		*prev = i;
188 		prev = &cpu_data(i).next;
189 	}
190 	*prev = first;
191 	local_flush_cache_all();
192 
193 	/* Ok, they are spinning and ready to go. */
194 }
195 
196 /* At each hardware IRQ, we get this called to forward IRQ reception
197  * to the next processor.  The caller must disable the IRQ level being
198  * serviced globally so that there are no double interrupts received.
199  *
200  * XXX See sparc64 irq.c.
201  */
202 void smp4m_irq_rotate(int cpu)
203 {
204 	int next = cpu_data(cpu).next;
205 	if (next != cpu)
206 		set_irq_udt(next);
207 }
208 
209 static struct smp_funcall {
210 	smpfunc_t func;
211 	unsigned long arg1;
212 	unsigned long arg2;
213 	unsigned long arg3;
214 	unsigned long arg4;
215 	unsigned long arg5;
216 	unsigned long processors_in[SUN4M_NCPUS];  /* Set when ipi entered. */
217 	unsigned long processors_out[SUN4M_NCPUS]; /* Set when ipi exited. */
218 } ccall_info;
219 
220 static DEFINE_SPINLOCK(cross_call_lock);
221 
222 /* Cross calls must be serialized, at least currently. */
223 static void smp4m_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
224 			     unsigned long arg2, unsigned long arg3,
225 			     unsigned long arg4)
226 {
227 		register int ncpus = SUN4M_NCPUS;
228 		unsigned long flags;
229 
230 		spin_lock_irqsave(&cross_call_lock, flags);
231 
232 		/* Init function glue. */
233 		ccall_info.func = func;
234 		ccall_info.arg1 = arg1;
235 		ccall_info.arg2 = arg2;
236 		ccall_info.arg3 = arg3;
237 		ccall_info.arg4 = arg4;
238 		ccall_info.arg5 = 0;
239 
240 		/* Init receive/complete mapping, plus fire the IPI's off. */
241 		{
242 			register int i;
243 
244 			cpu_clear(smp_processor_id(), mask);
245 			cpus_and(mask, cpu_online_map, mask);
246 			for(i = 0; i < ncpus; i++) {
247 				if (cpu_isset(i, mask)) {
248 					ccall_info.processors_in[i] = 0;
249 					ccall_info.processors_out[i] = 0;
250 					set_cpu_int(i, IRQ_CROSS_CALL);
251 				} else {
252 					ccall_info.processors_in[i] = 1;
253 					ccall_info.processors_out[i] = 1;
254 				}
255 			}
256 		}
257 
258 		{
259 			register int i;
260 
261 			i = 0;
262 			do {
263 				if (!cpu_isset(i, mask))
264 					continue;
265 				while(!ccall_info.processors_in[i])
266 					barrier();
267 			} while(++i < ncpus);
268 
269 			i = 0;
270 			do {
271 				if (!cpu_isset(i, mask))
272 					continue;
273 				while(!ccall_info.processors_out[i])
274 					barrier();
275 			} while(++i < ncpus);
276 		}
277 
278 		spin_unlock_irqrestore(&cross_call_lock, flags);
279 }
280 
281 /* Running cross calls. */
282 void smp4m_cross_call_irq(void)
283 {
284 	int i = smp_processor_id();
285 
286 	ccall_info.processors_in[i] = 1;
287 	ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
288 			ccall_info.arg4, ccall_info.arg5);
289 	ccall_info.processors_out[i] = 1;
290 }
291 
292 extern void sun4m_clear_profile_irq(int cpu);
293 
294 void smp4m_percpu_timer_interrupt(struct pt_regs *regs)
295 {
296 	struct pt_regs *old_regs;
297 	int cpu = smp_processor_id();
298 
299 	old_regs = set_irq_regs(regs);
300 
301 	sun4m_clear_profile_irq(cpu);
302 
303 	profile_tick(CPU_PROFILING);
304 
305 	if(!--prof_counter(cpu)) {
306 		int user = user_mode(regs);
307 
308 		irq_enter();
309 		update_process_times(user);
310 		irq_exit();
311 
312 		prof_counter(cpu) = prof_multiplier(cpu);
313 	}
314 	set_irq_regs(old_regs);
315 }
316 
317 extern unsigned int lvl14_resolution;
318 
319 static void __cpuinit smp_setup_percpu_timer(void)
320 {
321 	int cpu = smp_processor_id();
322 
323 	prof_counter(cpu) = prof_multiplier(cpu) = 1;
324 	load_profile_irq(cpu, lvl14_resolution);
325 
326 	if(cpu == boot_cpu_id)
327 		enable_pil_irq(14);
328 }
329 
330 static void __init smp4m_blackbox_id(unsigned *addr)
331 {
332 	int rd = *addr & 0x3e000000;
333 	int rs1 = rd >> 11;
334 
335 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
336 	addr[1] = 0x8130200c | rd | rs1;    	/* srl reg, 0xc, reg */
337 	addr[2] = 0x80082003 | rd | rs1;	/* and reg, 3, reg */
338 }
339 
340 static void __init smp4m_blackbox_current(unsigned *addr)
341 {
342 	int rd = *addr & 0x3e000000;
343 	int rs1 = rd >> 11;
344 
345 	addr[0] = 0x81580000 | rd;		/* rd %tbr, reg */
346 	addr[2] = 0x8130200a | rd | rs1;    	/* srl reg, 0xa, reg */
347 	addr[4] = 0x8008200c | rd | rs1;	/* and reg, 0xc, reg */
348 }
349 
350 void __init sun4m_init_smp(void)
351 {
352 	BTFIXUPSET_BLACKBOX(hard_smp_processor_id, smp4m_blackbox_id);
353 	BTFIXUPSET_BLACKBOX(load_current, smp4m_blackbox_current);
354 	BTFIXUPSET_CALL(smp_cross_call, smp4m_cross_call, BTFIXUPCALL_NORM);
355 	BTFIXUPSET_CALL(__hard_smp_processor_id, __smp4m_processor_id, BTFIXUPCALL_NORM);
356 }
357