2 * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * RajeshwarR: Dec 11, 2007
9 * -- Added support for Inter Processor Interrupts
11 * Vineetg: Nov 1st, 2007
12 * -- Initial Write (Borrowed heavily from ARM)
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/spinlock.h>
18 #include <linux/sched.h>
19 #include <linux/interrupt.h>
20 #include <linux/profile.h>
21 #include <linux/errno.h>
22 #include <linux/err.h>
24 #include <linux/cpu.h>
25 #include <linux/smp.h>
26 #include <linux/irq.h>
27 #include <linux/delay.h>
28 #include <linux/atomic.h>
29 #include <linux/percpu.h>
30 #include <linux/cpumask.h>
31 #include <linux/spinlock_types.h>
32 #include <linux/reboot.h>
33 #include <asm/processor.h>
34 #include <asm/setup.h>
35 #include <asm/mach_desc.h>
37 arch_spinlock_t smp_atomic_ops_lock = __ARCH_SPIN_LOCK_UNLOCKED;
38 arch_spinlock_t smp_bitops_lock = __ARCH_SPIN_LOCK_UNLOCKED;
40 /* XXX: per cpu ? Only needed once in early seconday boot */
41 struct task_struct *secondary_idle_tsk;
43 /* Called from start_kernel */
44 void __init smp_prepare_boot_cpu(void)
49 * Initialise the CPU possible map early - this describes the CPUs
50 * which may be present or become present in the system.
52 void __init smp_init_cpus(void)
56 for (i = 0; i < NR_CPUS; i++)
57 set_cpu_possible(i, true);
60 /* called from init ( ) => process 1 */
61 void __init smp_prepare_cpus(unsigned int max_cpus)
66 * Initialise the present map, which describes the set of CPUs
67 * actually populated at the present time.
69 for (i = 0; i < max_cpus; i++)
70 set_cpu_present(i, true);
73 void __init smp_cpus_done(unsigned int max_cpus)
79 * After power-up, a non Master CPU needs to wait for Master to kick start it
81 * The default implementation halts
83 * This relies on platform specific support allowing Master to directly set
84 * this CPU's PC (to be @first_lines_of_secondary() and kick start it.
86 * In lack of such h/w assist, platforms can override this function
87 * - make this function busy-spin on a token, eventually set by Master
88 * (from arc_platform_smp_wakeup_cpu())
89 * - Once token is available, jump to @first_lines_of_secondary
92 * Alert: can NOT use stack here as it has not been determined/setup for CPU.
93 * If it turns out to be elaborate, it's better to code it in assembly
96 void __attribute__((weak)) arc_platform_smp_wait_to_boot(int cpu)
99 * As a hack for debugging - since debugger will single-step over the
100 * FLAG insn - wrap the halt itself it in a self loop
102 __asm__ __volatile__(
109 * The very first "C" code executed by secondary
110 * Called from asm stub in head.S
111 * "current"/R25 already setup by low level boot code
113 void __cpuinit start_kernel_secondary(void)
115 struct mm_struct *mm = &init_mm;
116 unsigned int cpu = smp_processor_id();
118 /* MMU, Caches, Vector Table, Interrupts etc */
121 atomic_inc(&mm->mm_users);
122 atomic_inc(&mm->mm_count);
123 current->active_mm = mm;
125 notify_cpu_starting(cpu);
126 set_cpu_online(cpu, true);
128 pr_info("## CPU%u LIVE ##: Executing Code...\n", cpu);
130 arc_platform_smp_init_cpu();
131 if (machine_desc->init_smp)
132 machine_desc->init_smp(smp_processor_id());
134 arc_local_timer_setup(cpu);
142 * Called from kernel_init( ) -> smp_init( ) - for each CPU
144 * At this point, Secondary Processor is "HALT"ed:
145 * -It booted, but was halted in head.S
146 * -It was configured to halt-on-reset
147 * So need to wake it up.
149 * Essential requirements being where to run from (PC) and stack (SP)
151 int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *idle)
153 unsigned long wait_till;
155 secondary_idle_tsk = idle;
157 pr_info("Idle Task [%d] %p", cpu, idle);
158 pr_info("Trying to bring up CPU%u ...\n", cpu);
160 arc_platform_smp_wakeup_cpu(cpu,
161 (unsigned long)first_lines_of_secondary);
163 /* wait for 1 sec after kicking the secondary */
164 wait_till = jiffies + HZ;
165 while (time_before(jiffies, wait_till)) {
170 if (!cpu_online(cpu)) {
171 pr_info("Timeout: CPU%u FAILED to comeup !!!\n", cpu);
175 secondary_idle_tsk = NULL;
183 int __init setup_profiling_timer(unsigned int multiplier)
188 /*****************************************************************************/
189 /* Inter Processor Interrupt Handling */
190 /*****************************************************************************/
193 * structures for inter-processor calls
194 * A Collection of single bit ipi messages
199 * TODO_rajesh investigate tlb message types.
200 * IPI Timer not needed because each ARC has an individual Interrupting Timer
206 IPI_CALL_FUNC_SINGLE,
214 static DEFINE_PER_CPU(struct ipi_data, ipi_data);
216 static void ipi_send_msg(const struct cpumask *callmap, enum ipi_msg_type msg)
221 local_irq_save(flags);
223 for_each_cpu(cpu, callmap) {
224 struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
225 set_bit(msg, &ipi->bits);
228 /* Call the platform specific cross-CPU call function */
229 arc_platform_ipi_send(callmap);
231 local_irq_restore(flags);
234 void smp_send_reschedule(int cpu)
236 ipi_send_msg(cpumask_of(cpu), IPI_RESCHEDULE);
239 void smp_send_stop(void)
241 struct cpumask targets;
242 cpumask_copy(&targets, cpu_online_mask);
243 cpumask_clear_cpu(smp_processor_id(), &targets);
244 ipi_send_msg(&targets, IPI_CPU_STOP);
247 void arch_send_call_function_single_ipi(int cpu)
249 ipi_send_msg(cpumask_of(cpu), IPI_CALL_FUNC_SINGLE);
252 void arch_send_call_function_ipi_mask(const struct cpumask *mask)
254 ipi_send_msg(mask, IPI_CALL_FUNC);
258 * ipi_cpu_stop - handle IPI from smp_send_stop()
260 static void ipi_cpu_stop(unsigned int cpu)
265 static inline void __do_IPI(unsigned long *ops, struct ipi_data *ipi, int cpu)
267 unsigned long msg = 0;
270 msg = find_next_bit(ops, BITS_PER_LONG, msg+1);
278 generic_smp_call_function_interrupt();
281 case IPI_CALL_FUNC_SINGLE:
282 generic_smp_call_function_single_interrupt();
289 } while (msg < BITS_PER_LONG);
294 * arch-common ISR to handle for inter-processor interrupts
295 * Has hooks for platform specific IPI
297 irqreturn_t do_IPI(int irq, void *dev_id)
299 int cpu = smp_processor_id();
300 struct ipi_data *ipi = &per_cpu(ipi_data, cpu);
303 arc_platform_ipi_clear(cpu, irq);
306 * XXX: is this loop really needed
307 * And do we need to move ipi_clean inside
309 while ((ops = xchg(&ipi->bits, 0)) != 0)
310 __do_IPI(&ops, ipi, cpu);
316 * API called by platform code to hookup arch-common ISR to their IPI IRQ
318 static DEFINE_PER_CPU(int, ipi_dev);
319 int smp_ipi_irq_setup(int cpu, int irq)
321 int *dev_id = &per_cpu(ipi_dev, smp_processor_id());
322 return request_percpu_irq(irq, do_IPI, "IPI Interrupt", dev_id);