Commit | Line | Data |
---|---|---|
43afdf50 RK |
1 | /* |
2 | * SMP support for Hexagon | |
3 | * | |
4 | * Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved. | |
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> | |
31 | ||
43afdf50 RK |
32 | #include <asm/time.h> /* timer_interrupt */ |
33 | #include <asm/hexagon_vm.h> | |
34 | ||
35 | #define BASE_IPI_IRQ 26 | |
36 | ||
37 | /* | |
0b5f9c00 | 38 | * cpu_possible_mask needs to be filled out prior to setup_per_cpu_areas |
43afdf50 RK |
39 | * (which is prior to any of our smp_prepare_cpu crap), in order to set |
40 | * up the... per_cpu areas. | |
41 | */ | |
42 | ||
43 | struct ipi_data { | |
44 | unsigned long bits; | |
45 | }; | |
46 | ||
47 | static DEFINE_PER_CPU(struct ipi_data, ipi_data); | |
48 | ||
49 | static inline void __handle_ipi(unsigned long *ops, struct ipi_data *ipi, | |
50 | int cpu) | |
51 | { | |
52 | unsigned long msg = 0; | |
53 | do { | |
54 | msg = find_next_bit(ops, BITS_PER_LONG, msg+1); | |
55 | ||
56 | switch (msg) { | |
57 | ||
58 | case IPI_TIMER: | |
59 | ipi_timer(); | |
60 | break; | |
61 | ||
62 | case IPI_CALL_FUNC: | |
63 | generic_smp_call_function_interrupt(); | |
64 | break; | |
65 | ||
66 | case IPI_CALL_FUNC_SINGLE: | |
67 | generic_smp_call_function_single_interrupt(); | |
68 | break; | |
69 | ||
70 | case IPI_CPU_STOP: | |
71 | /* | |
72 | * call vmstop() | |
73 | */ | |
74 | __vmstop(); | |
75 | break; | |
76 | ||
77 | case IPI_RESCHEDULE: | |
78 | scheduler_ipi(); | |
79 | break; | |
80 | } | |
81 | } while (msg < BITS_PER_LONG); | |
82 | } | |
83 | ||
84 | /* Used for IPI call from other CPU's to unmask int */ | |
85 | void smp_vm_unmask_irq(void *info) | |
86 | { | |
87 | __vmintop_locen((long) info); | |
88 | } | |
89 | ||
90 | ||
91 | /* | |
92 | * This is based on Alpha's IPI stuff. | |
93 | * Supposed to take (int, void*) as args now. | |
94 | * Specifically, first arg is irq, second is the irq_desc. | |
95 | */ | |
96 | ||
97 | irqreturn_t handle_ipi(int irq, void *desc) | |
98 | { | |
99 | int cpu = smp_processor_id(); | |
100 | struct ipi_data *ipi = &per_cpu(ipi_data, cpu); | |
101 | unsigned long ops; | |
102 | ||
103 | while ((ops = xchg(&ipi->bits, 0)) != 0) | |
104 | __handle_ipi(&ops, ipi, cpu); | |
105 | return IRQ_HANDLED; | |
106 | } | |
107 | ||
108 | void send_ipi(const struct cpumask *cpumask, enum ipi_message_type msg) | |
109 | { | |
110 | unsigned long flags; | |
111 | unsigned long cpu; | |
112 | unsigned long retval; | |
113 | ||
114 | local_irq_save(flags); | |
115 | ||
116 | for_each_cpu(cpu, cpumask) { | |
117 | struct ipi_data *ipi = &per_cpu(ipi_data, cpu); | |
118 | ||
119 | set_bit(msg, &ipi->bits); | |
120 | /* Possible barrier here */ | |
121 | retval = __vmintop_post(BASE_IPI_IRQ+cpu); | |
122 | ||
123 | if (retval != 0) { | |
124 | printk(KERN_ERR "interrupt %ld not configured?\n", | |
125 | BASE_IPI_IRQ+cpu); | |
126 | } | |
127 | } | |
128 | ||
129 | local_irq_restore(flags); | |
130 | } | |
131 | ||
132 | static struct irqaction ipi_intdesc = { | |
133 | .handler = handle_ipi, | |
134 | .flags = IRQF_TRIGGER_RISING, | |
135 | .name = "ipi_handler" | |
136 | }; | |
137 | ||
138 | void __init smp_prepare_boot_cpu(void) | |
139 | { | |
140 | } | |
141 | ||
142 | /* | |
143 | * interrupts should already be disabled from the VM | |
144 | * SP should already be correct; need to set THREADINFO_REG | |
145 | * to point to current thread info | |
146 | */ | |
147 | ||
148 | void __cpuinit start_secondary(void) | |
149 | { | |
150 | unsigned int cpu; | |
151 | unsigned long thread_ptr; | |
152 | ||
153 | /* Calculate thread_info pointer from stack pointer */ | |
154 | __asm__ __volatile__( | |
155 | "%0 = SP;\n" | |
156 | : "=r" (thread_ptr) | |
157 | ); | |
158 | ||
159 | thread_ptr = thread_ptr & ~(THREAD_SIZE-1); | |
160 | ||
161 | __asm__ __volatile__( | |
162 | QUOTED_THREADINFO_REG " = %0;\n" | |
163 | : | |
164 | : "r" (thread_ptr) | |
165 | ); | |
166 | ||
167 | /* Set the memory struct */ | |
168 | atomic_inc(&init_mm.mm_count); | |
169 | current->active_mm = &init_mm; | |
170 | ||
171 | cpu = smp_processor_id(); | |
172 | ||
173 | setup_irq(BASE_IPI_IRQ + cpu, &ipi_intdesc); | |
174 | ||
175 | /* Register the clock_event dummy */ | |
176 | setup_percpu_clockdev(); | |
177 | ||
178 | printk(KERN_INFO "%s cpu %d\n", __func__, current_thread_info()->cpu); | |
179 | ||
180 | set_cpu_online(cpu, true); | |
43afdf50 RK |
181 | local_irq_enable(); |
182 | ||
183 | cpu_idle(); | |
184 | } | |
185 | ||
186 | ||
187 | /* | |
188 | * called once for each present cpu | |
189 | * apparently starts up the CPU and then | |
190 | * maintains control until "cpu_online(cpu)" is set. | |
191 | */ | |
192 | ||
193 | int __cpuinit __cpu_up(unsigned int cpu) | |
194 | { | |
195 | struct task_struct *idle; | |
196 | struct thread_info *thread; | |
197 | void *stack_start; | |
198 | ||
199 | /* Create new init task for the CPU */ | |
200 | idle = fork_idle(cpu); | |
201 | if (IS_ERR(idle)) | |
202 | panic(KERN_ERR "fork_idle failed\n"); | |
203 | ||
204 | thread = (struct thread_info *)idle->stack; | |
205 | thread->cpu = cpu; | |
206 | ||
207 | /* Boot to the head. */ | |
208 | stack_start = ((void *) thread) + THREAD_SIZE; | |
209 | __vmstart(start_secondary, stack_start); | |
210 | ||
0b5f9c00 | 211 | while (!cpu_online(cpu)) |
43afdf50 RK |
212 | barrier(); |
213 | ||
214 | return 0; | |
215 | } | |
216 | ||
217 | void __init smp_cpus_done(unsigned int max_cpus) | |
218 | { | |
219 | } | |
220 | ||
221 | void __init smp_prepare_cpus(unsigned int max_cpus) | |
222 | { | |
223 | int i; | |
224 | ||
225 | /* | |
226 | * should eventually have some sort of machine | |
227 | * descriptor that has this stuff | |
228 | */ | |
229 | ||
230 | /* Right now, let's just fake it. */ | |
231 | for (i = 0; i < max_cpus; i++) | |
0b5f9c00 | 232 | set_cpu_present(i, true); |
43afdf50 RK |
233 | |
234 | /* Also need to register the interrupts for IPI */ | |
235 | if (max_cpus > 1) | |
236 | setup_irq(BASE_IPI_IRQ, &ipi_intdesc); | |
237 | } | |
238 | ||
239 | void smp_send_reschedule(int cpu) | |
240 | { | |
241 | send_ipi(cpumask_of(cpu), IPI_RESCHEDULE); | |
242 | } | |
243 | ||
244 | void smp_send_stop(void) | |
245 | { | |
246 | struct cpumask targets; | |
247 | cpumask_copy(&targets, cpu_online_mask); | |
248 | cpumask_clear_cpu(smp_processor_id(), &targets); | |
249 | send_ipi(&targets, IPI_CPU_STOP); | |
250 | } | |
251 | ||
252 | void arch_send_call_function_single_ipi(int cpu) | |
253 | { | |
254 | send_ipi(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE); | |
255 | } | |
256 | ||
257 | void arch_send_call_function_ipi_mask(const struct cpumask *mask) | |
258 | { | |
259 | send_ipi(mask, IPI_CALL_FUNC); | |
260 | } | |
261 | ||
262 | int setup_profiling_timer(unsigned int multiplier) | |
263 | { | |
264 | return -EINVAL; | |
265 | } | |
266 | ||
267 | void smp_start_cpus(void) | |
268 | { | |
269 | int i; | |
270 | ||
271 | for (i = 0; i < NR_CPUS; i++) | |
0b5f9c00 | 272 | set_cpu_possible(i, true); |
43afdf50 | 273 | } |