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43afdf50 RK |
1 | /* |
2 | * SMP support for Hexagon | |
3 | * | |
e1858b2a | 4 | * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved. |
43afdf50 RK |
5 | * |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License version 2 and | |
8 | * only version 2 as published by the Free Software Foundation. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA | |
18 | * 02110-1301, USA. | |
19 | */ | |
20 | ||
21 | #include <linux/err.h> | |
22 | #include <linux/errno.h> | |
23 | #include <linux/kernel.h> | |
24 | #include <linux/init.h> | |
25 | #include <linux/interrupt.h> | |
26 | #include <linux/module.h> | |
27 | #include <linux/percpu.h> | |
28 | #include <linux/sched.h> | |
29 | #include <linux/smp.h> | |
30 | #include <linux/spinlock.h> | |
e00574b7 | 31 | #include <linux/cpu.h> |
43afdf50 | 32 | |
43afdf50 RK |
33 | #include <asm/time.h> /* timer_interrupt */ |
34 | #include <asm/hexagon_vm.h> | |
35 | ||
36 | #define BASE_IPI_IRQ 26 | |
37 | ||
38 | /* | |
0b5f9c00 | 39 | * cpu_possible_mask needs to be filled out prior to setup_per_cpu_areas |
43afdf50 RK |
40 | * (which is prior to any of our smp_prepare_cpu crap), in order to set |
41 | * up the... per_cpu areas. | |
42 | */ | |
43 | ||
44 | struct ipi_data { | |
45 | unsigned long bits; | |
46 | }; | |
47 | ||
48 | static DEFINE_PER_CPU(struct ipi_data, ipi_data); | |
49 | ||
50 | static inline void __handle_ipi(unsigned long *ops, struct ipi_data *ipi, | |
51 | int cpu) | |
52 | { | |
53 | unsigned long msg = 0; | |
54 | do { | |
55 | msg = find_next_bit(ops, BITS_PER_LONG, msg+1); | |
56 | ||
57 | switch (msg) { | |
58 | ||
59 | case IPI_TIMER: | |
60 | ipi_timer(); | |
61 | break; | |
62 | ||
63 | case IPI_CALL_FUNC: | |
64 | generic_smp_call_function_interrupt(); | |
65 | break; | |
66 | ||
67 | case IPI_CALL_FUNC_SINGLE: | |
68 | generic_smp_call_function_single_interrupt(); | |
69 | break; | |
70 | ||
71 | case IPI_CPU_STOP: | |
72 | /* | |
73 | * call vmstop() | |
74 | */ | |
75 | __vmstop(); | |
76 | break; | |
77 | ||
78 | case IPI_RESCHEDULE: | |
79 | scheduler_ipi(); | |
80 | break; | |
81 | } | |
82 | } while (msg < BITS_PER_LONG); | |
83 | } | |
84 | ||
85 | /* Used for IPI call from other CPU's to unmask int */ | |
86 | void smp_vm_unmask_irq(void *info) | |
87 | { | |
88 | __vmintop_locen((long) info); | |
89 | } | |
90 | ||
91 | ||
92 | /* | |
93 | * This is based on Alpha's IPI stuff. | |
94 | * Supposed to take (int, void*) as args now. | |
95 | * Specifically, first arg is irq, second is the irq_desc. | |
96 | */ | |
97 | ||
98 | irqreturn_t handle_ipi(int irq, void *desc) | |
99 | { | |
100 | int cpu = smp_processor_id(); | |
101 | struct ipi_data *ipi = &per_cpu(ipi_data, cpu); | |
102 | unsigned long ops; | |
103 | ||
104 | while ((ops = xchg(&ipi->bits, 0)) != 0) | |
105 | __handle_ipi(&ops, ipi, cpu); | |
106 | return IRQ_HANDLED; | |
107 | } | |
108 | ||
109 | void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg) | |
110 | { | |
111 | unsigned long flags; | |
112 | unsigned long cpu; | |
113 | unsigned long retval; | |
114 | ||
115 | local_irq_save(flags); | |
116 | ||
117 | for_each_cpu(cpu, cpumask) { | |
118 | struct ipi_data *ipi = &per_cpu(ipi_data, cpu); | |
119 | ||
120 | set_bit(msg, &ipi->bits); | |
121 | /* Possible barrier here */ | |
122 | retval = __vmintop_post(BASE_IPI_IRQ+cpu); | |
123 | ||
124 | if (retval != 0) { | |
125 | printk(KERN_ERR "interrupt %ld not configured?\n", | |
126 | BASE_IPI_IRQ+cpu); | |
127 | } | |
128 | } | |
129 | ||
130 | local_irq_restore(flags); | |
131 | } | |
132 | ||
133 | static struct irqaction ipi_intdesc = { | |
134 | .handler = handle_ipi, | |
135 | .flags = IRQF_TRIGGER_RISING, | |
136 | .name = "ipi_handler" | |
137 | }; | |
138 | ||
139 | void __init smp_prepare_boot_cpu(void) | |
140 | { | |
141 | } | |
142 | ||
143 | /* | |
144 | * interrupts should already be disabled from the VM | |
145 | * SP should already be correct; need to set THREADINFO_REG | |
146 | * to point to current thread info | |
147 | */ | |
148 | ||
7ddc8399 | 149 | void start_secondary(void) |
43afdf50 RK |
150 | { |
151 | unsigned int cpu; | |
152 | unsigned long thread_ptr; | |
153 | ||
154 | /* Calculate thread_info pointer from stack pointer */ | |
155 | __asm__ __volatile__( | |
156 | "%0 = SP;\n" | |
157 | : "=r" (thread_ptr) | |
158 | ); | |
159 | ||
160 | thread_ptr = thread_ptr & ~(THREAD_SIZE-1); | |
161 | ||
162 | __asm__ __volatile__( | |
163 | QUOTED_THREADINFO_REG " = %0;\n" | |
164 | : | |
165 | : "r" (thread_ptr) | |
166 | ); | |
167 | ||
168 | /* Set the memory struct */ | |
169 | atomic_inc(&init_mm.mm_count); | |
170 | current->active_mm = &init_mm; | |
171 | ||
172 | cpu = smp_processor_id(); | |
173 | ||
174 | setup_irq(BASE_IPI_IRQ + cpu, &ipi_intdesc); | |
175 | ||
176 | /* Register the clock_event dummy */ | |
177 | setup_percpu_clockdev(); | |
178 | ||
179 | printk(KERN_INFO "%s cpu %d\n", __func__, current_thread_info()->cpu); | |
180 | ||
57f27cca SB |
181 | notify_cpu_starting(cpu); |
182 | ||
43afdf50 | 183 | set_cpu_online(cpu, true); |
57f27cca | 184 | |
43afdf50 RK |
185 | local_irq_enable(); |
186 | ||
4e0fcc56 | 187 | cpu_startup_entry(CPUHP_ONLINE); |
43afdf50 RK |
188 | } |
189 | ||
190 | ||
191 | /* | |
192 | * called once for each present cpu | |
193 | * apparently starts up the CPU and then | |
194 | * maintains control until "cpu_online(cpu)" is set. | |
195 | */ | |
196 | ||
7ddc8399 | 197 | int __cpu_up(unsigned int cpu, struct task_struct *idle) |
43afdf50 | 198 | { |
3b0132ce | 199 | struct thread_info *thread = (struct thread_info *)idle->stack; |
43afdf50 RK |
200 | void *stack_start; |
201 | ||
43afdf50 RK |
202 | thread->cpu = cpu; |
203 | ||
204 | /* Boot to the head. */ | |
205 | stack_start = ((void *) thread) + THREAD_SIZE; | |
206 | __vmstart(start_secondary, stack_start); | |
207 | ||
0b5f9c00 | 208 | while (!cpu_online(cpu)) |
43afdf50 RK |
209 | barrier(); |
210 | ||
211 | return 0; | |
212 | } | |
213 | ||
214 | void __init smp_cpus_done(unsigned int max_cpus) | |
215 | { | |
216 | } | |
217 | ||
218 | void __init smp_prepare_cpus(unsigned int max_cpus) | |
219 | { | |
220 | int i; | |
221 | ||
222 | /* | |
223 | * should eventually have some sort of machine | |
224 | * descriptor that has this stuff | |
225 | */ | |
226 | ||
227 | /* Right now, let's just fake it. */ | |
228 | for (i = 0; i < max_cpus; i++) | |
0b5f9c00 | 229 | set_cpu_present(i, true); |
43afdf50 RK |
230 | |
231 | /* Also need to register the interrupts for IPI */ | |
232 | if (max_cpus > 1) | |
233 | setup_irq(BASE_IPI_IRQ, &ipi_intdesc); | |
234 | } | |
235 | ||
236 | void smp_send_reschedule(int cpu) | |
237 | { | |
238 | send_ipi(cpumask_of(cpu), IPI_RESCHEDULE); | |
239 | } | |
240 | ||
241 | void smp_send_stop(void) | |
242 | { | |
243 | struct cpumask targets; | |
244 | cpumask_copy(&targets, cpu_online_mask); | |
245 | cpumask_clear_cpu(smp_processor_id(), &targets); | |
246 | send_ipi(&targets, IPI_CPU_STOP); | |
247 | } | |
248 | ||
249 | void arch_send_call_function_single_ipi(int cpu) | |
250 | { | |
251 | send_ipi(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE); | |
252 | } | |
253 | ||
254 | void arch_send_call_function_ipi_mask(const struct cpumask *mask) | |
255 | { | |
256 | send_ipi(mask, IPI_CALL_FUNC); | |
257 | } | |
258 | ||
259 | int setup_profiling_timer(unsigned int multiplier) | |
260 | { | |
261 | return -EINVAL; | |
262 | } | |
263 | ||
264 | void smp_start_cpus(void) | |
265 | { | |
266 | int i; | |
267 | ||
268 | for (i = 0; i < NR_CPUS; i++) | |
0b5f9c00 | 269 | set_cpu_possible(i, true); |
43afdf50 | 270 | } |