1 /*
2 * sun4m SMP support.
3 *
4 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
5 */
6
7 #include <linux/clockchips.h>
8 #include <linux/interrupt.h>
9 #include <linux/profile.h>
10 #include <linux/delay.h>
11 #include <linux/sched.h>
12 #include <linux/cpu.h>
13
14 #include <asm/cacheflush.h>
15 #include <asm/switch_to.h>
16 #include <asm/tlbflush.h>
17 #include <asm/timer.h>
18 #include <asm/oplib.h>
19
20 #include "irq.h"
21 #include "kernel.h"
22
23 #define IRQ_IPI_SINGLE 12
24 #define IRQ_IPI_MASK 13
25 #define IRQ_IPI_RESCHED 14
26 #define IRQ_CROSS_CALL 15
27
28 static inline unsigned long
swap_ulong(volatile unsigned long * ptr,unsigned long val)29 swap_ulong(volatile unsigned long *ptr, unsigned long val)
30 {
31 __asm__ __volatile__("swap [%1], %0\n\t" :
32 "=&r" (val), "=&r" (ptr) :
33 "0" (val), "1" (ptr));
34 return val;
35 }
36
sun4m_cpu_pre_starting(void * arg)37 void sun4m_cpu_pre_starting(void *arg)
38 {
39 }
40
sun4m_cpu_pre_online(void * arg)41 void sun4m_cpu_pre_online(void *arg)
42 {
43 int cpuid = hard_smp_processor_id();
44
45 /* Allow master to continue. The master will then give us the
46 * go-ahead by setting the smp_commenced_mask and will wait without
47 * timeouts until our setup is completed fully (signified by
48 * our bit being set in the cpu_online_mask).
49 */
50 swap_ulong(&cpu_callin_map[cpuid], 1);
51
52 /* XXX: What's up with all the flushes? */
53 local_ops->cache_all();
54 local_ops->tlb_all();
55
56 /* Fix idle thread fields. */
57 __asm__ __volatile__("ld [%0], %%g6\n\t"
58 : : "r" (¤t_set[cpuid])
59 : "memory" /* paranoid */);
60
61 /* Attach to the address space of init_task. */
62 atomic_inc(&init_mm.mm_count);
63 current->active_mm = &init_mm;
64
65 while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
66 mb();
67 }
68
69 /*
70 * Cycle through the processors asking the PROM to start each one.
71 */
smp4m_boot_cpus(void)72 void __init smp4m_boot_cpus(void)
73 {
74 sun4m_unmask_profile_irq();
75 local_ops->cache_all();
76 }
77
smp4m_boot_one_cpu(int i,struct task_struct * idle)78 int smp4m_boot_one_cpu(int i, struct task_struct *idle)
79 {
80 unsigned long *entry = &sun4m_cpu_startup;
81 int timeout;
82 int cpu_node;
83
84 cpu_find_by_mid(i, &cpu_node);
85 current_set[i] = task_thread_info(idle);
86
87 /* See trampoline.S for details... */
88 entry += ((i - 1) * 3);
89
90 /*
91 * Initialize the contexts table
92 * Since the call to prom_startcpu() trashes the structure,
93 * we need to re-initialize it for each cpu
94 */
95 smp_penguin_ctable.which_io = 0;
96 smp_penguin_ctable.phys_addr = (unsigned int) srmmu_ctx_table_phys;
97 smp_penguin_ctable.reg_size = 0;
98
99 /* whirrr, whirrr, whirrrrrrrrr... */
100 printk(KERN_INFO "Starting CPU %d at %p\n", i, entry);
101 local_ops->cache_all();
102 prom_startcpu(cpu_node, &smp_penguin_ctable, 0, (char *)entry);
103
104 /* wheee... it's going... */
105 for (timeout = 0; timeout < 10000; timeout++) {
106 if (cpu_callin_map[i])
107 break;
108 udelay(200);
109 }
110
111 if (!(cpu_callin_map[i])) {
112 printk(KERN_ERR "Processor %d is stuck.\n", i);
113 return -ENODEV;
114 }
115
116 local_ops->cache_all();
117 return 0;
118 }
119
smp4m_smp_done(void)120 void __init smp4m_smp_done(void)
121 {
122 int i, first;
123 int *prev;
124
125 /* setup cpu list for irq rotation */
126 first = 0;
127 prev = &first;
128 for_each_online_cpu(i) {
129 *prev = i;
130 prev = &cpu_data(i).next;
131 }
132 *prev = first;
133 local_ops->cache_all();
134
135 /* Ok, they are spinning and ready to go. */
136 }
137
sun4m_send_ipi(int cpu,int level)138 static void sun4m_send_ipi(int cpu, int level)
139 {
140 sbus_writel(SUN4M_SOFT_INT(level), &sun4m_irq_percpu[cpu]->set);
141 }
142
sun4m_ipi_resched(int cpu)143 static void sun4m_ipi_resched(int cpu)
144 {
145 sun4m_send_ipi(cpu, IRQ_IPI_RESCHED);
146 }
147
sun4m_ipi_single(int cpu)148 static void sun4m_ipi_single(int cpu)
149 {
150 sun4m_send_ipi(cpu, IRQ_IPI_SINGLE);
151 }
152
sun4m_ipi_mask_one(int cpu)153 static void sun4m_ipi_mask_one(int cpu)
154 {
155 sun4m_send_ipi(cpu, IRQ_IPI_MASK);
156 }
157
158 static struct smp_funcall {
159 smpfunc_t func;
160 unsigned long arg1;
161 unsigned long arg2;
162 unsigned long arg3;
163 unsigned long arg4;
164 unsigned long arg5;
165 unsigned long processors_in[SUN4M_NCPUS]; /* Set when ipi entered. */
166 unsigned long processors_out[SUN4M_NCPUS]; /* Set when ipi exited. */
167 } ccall_info;
168
169 static DEFINE_SPINLOCK(cross_call_lock);
170
171 /* Cross calls must be serialized, at least currently. */
sun4m_cross_call(smpfunc_t func,cpumask_t mask,unsigned long arg1,unsigned long arg2,unsigned long arg3,unsigned long arg4)172 static void sun4m_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
173 unsigned long arg2, unsigned long arg3,
174 unsigned long arg4)
175 {
176 register int ncpus = SUN4M_NCPUS;
177 unsigned long flags;
178
179 spin_lock_irqsave(&cross_call_lock, flags);
180
181 /* Init function glue. */
182 ccall_info.func = func;
183 ccall_info.arg1 = arg1;
184 ccall_info.arg2 = arg2;
185 ccall_info.arg3 = arg3;
186 ccall_info.arg4 = arg4;
187 ccall_info.arg5 = 0;
188
189 /* Init receive/complete mapping, plus fire the IPI's off. */
190 {
191 register int i;
192
193 cpumask_clear_cpu(smp_processor_id(), &mask);
194 cpumask_and(&mask, cpu_online_mask, &mask);
195 for (i = 0; i < ncpus; i++) {
196 if (cpumask_test_cpu(i, &mask)) {
197 ccall_info.processors_in[i] = 0;
198 ccall_info.processors_out[i] = 0;
199 sun4m_send_ipi(i, IRQ_CROSS_CALL);
200 } else {
201 ccall_info.processors_in[i] = 1;
202 ccall_info.processors_out[i] = 1;
203 }
204 }
205 }
206
207 {
208 register int i;
209
210 i = 0;
211 do {
212 if (!cpumask_test_cpu(i, &mask))
213 continue;
214 while (!ccall_info.processors_in[i])
215 barrier();
216 } while (++i < ncpus);
217
218 i = 0;
219 do {
220 if (!cpumask_test_cpu(i, &mask))
221 continue;
222 while (!ccall_info.processors_out[i])
223 barrier();
224 } while (++i < ncpus);
225 }
226 spin_unlock_irqrestore(&cross_call_lock, flags);
227 }
228
229 /* Running cross calls. */
smp4m_cross_call_irq(void)230 void smp4m_cross_call_irq(void)
231 {
232 int i = smp_processor_id();
233
234 ccall_info.processors_in[i] = 1;
235 ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
236 ccall_info.arg4, ccall_info.arg5);
237 ccall_info.processors_out[i] = 1;
238 }
239
smp4m_percpu_timer_interrupt(struct pt_regs * regs)240 void smp4m_percpu_timer_interrupt(struct pt_regs *regs)
241 {
242 struct pt_regs *old_regs;
243 struct clock_event_device *ce;
244 int cpu = smp_processor_id();
245
246 old_regs = set_irq_regs(regs);
247
248 ce = &per_cpu(sparc32_clockevent, cpu);
249
250 if (clockevent_state_periodic(ce))
251 sun4m_clear_profile_irq(cpu);
252 else
253 sparc_config.load_profile_irq(cpu, 0); /* Is this needless? */
254
255 irq_enter();
256 ce->event_handler(ce);
257 irq_exit();
258
259 set_irq_regs(old_regs);
260 }
261
262 static const struct sparc32_ipi_ops sun4m_ipi_ops = {
263 .cross_call = sun4m_cross_call,
264 .resched = sun4m_ipi_resched,
265 .single = sun4m_ipi_single,
266 .mask_one = sun4m_ipi_mask_one,
267 };
268
sun4m_init_smp(void)269 void __init sun4m_init_smp(void)
270 {
271 sparc32_ipi_ops = &sun4m_ipi_ops;
272 }
273