141195d23SVineet Gupta /* 241195d23SVineet Gupta * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) 341195d23SVineet Gupta * 441195d23SVineet Gupta * This program is free software; you can redistribute it and/or modify 541195d23SVineet Gupta * it under the terms of the GNU General Public License version 2 as 641195d23SVineet Gupta * published by the Free Software Foundation. 741195d23SVineet Gupta * 841195d23SVineet Gupta * RajeshwarR: Dec 11, 2007 941195d23SVineet Gupta * -- Added support for Inter Processor Interrupts 1041195d23SVineet Gupta * 1141195d23SVineet Gupta * Vineetg: Nov 1st, 2007 1241195d23SVineet Gupta * -- Initial Write (Borrowed heavily from ARM) 1341195d23SVineet Gupta */ 1441195d23SVineet Gupta 1541195d23SVineet Gupta #include <linux/module.h> 1641195d23SVineet Gupta #include <linux/init.h> 1741195d23SVineet Gupta #include <linux/spinlock.h> 1841195d23SVineet Gupta #include <linux/sched.h> 1941195d23SVineet Gupta #include <linux/interrupt.h> 2041195d23SVineet Gupta #include <linux/profile.h> 2141195d23SVineet Gupta #include <linux/errno.h> 2241195d23SVineet Gupta #include <linux/err.h> 2341195d23SVineet Gupta #include <linux/mm.h> 2441195d23SVineet Gupta #include <linux/cpu.h> 2541195d23SVineet Gupta #include <linux/smp.h> 2641195d23SVineet Gupta #include <linux/irq.h> 2741195d23SVineet Gupta #include <linux/delay.h> 2841195d23SVineet Gupta #include <linux/atomic.h> 2941195d23SVineet Gupta #include <linux/percpu.h> 3041195d23SVineet Gupta #include <linux/cpumask.h> 3141195d23SVineet Gupta #include <linux/spinlock_types.h> 3241195d23SVineet Gupta #include <linux/reboot.h> 3341195d23SVineet Gupta #include <asm/processor.h> 3441195d23SVineet Gupta #include <asm/setup.h> 3503a6d28cSVineet Gupta #include <asm/mach_desc.h> 3641195d23SVineet Gupta 3741195d23SVineet Gupta arch_spinlock_t smp_atomic_ops_lock = __ARCH_SPIN_LOCK_UNLOCKED; 3841195d23SVineet Gupta arch_spinlock_t smp_bitops_lock = __ARCH_SPIN_LOCK_UNLOCKED; 3941195d23SVineet Gupta 4010b12718SVineet Gupta struct plat_smp_ops plat_smp_ops; 4110b12718SVineet Gupta 4241195d23SVineet Gupta /* XXX: per cpu ? Only needed once in early seconday boot */ 4341195d23SVineet Gupta struct task_struct *secondary_idle_tsk; 4441195d23SVineet Gupta 4541195d23SVineet Gupta /* Called from start_kernel */ 4641195d23SVineet Gupta void __init smp_prepare_boot_cpu(void) 4741195d23SVineet Gupta { 4841195d23SVineet Gupta } 4941195d23SVineet Gupta 5041195d23SVineet Gupta /* 5141195d23SVineet Gupta * Initialise the CPU possible map early - this describes the CPUs 5241195d23SVineet Gupta * which may be present or become present in the system. 5341195d23SVineet Gupta */ 5441195d23SVineet Gupta void __init smp_init_cpus(void) 5541195d23SVineet Gupta { 5641195d23SVineet Gupta unsigned int i; 5741195d23SVineet Gupta 5841195d23SVineet Gupta for (i = 0; i < NR_CPUS; i++) 5941195d23SVineet Gupta set_cpu_possible(i, true); 6041195d23SVineet Gupta } 6141195d23SVineet Gupta 6241195d23SVineet Gupta /* called from init ( ) => process 1 */ 6341195d23SVineet Gupta void __init smp_prepare_cpus(unsigned int max_cpus) 6441195d23SVineet Gupta { 6541195d23SVineet Gupta int i; 6641195d23SVineet Gupta 6741195d23SVineet Gupta /* 6841195d23SVineet Gupta * Initialise the present map, which describes the set of CPUs 6941195d23SVineet Gupta * actually populated at the present time. 7041195d23SVineet Gupta */ 7141195d23SVineet Gupta for (i = 0; i < max_cpus; i++) 7241195d23SVineet Gupta set_cpu_present(i, true); 7341195d23SVineet Gupta } 7441195d23SVineet Gupta 7541195d23SVineet Gupta void __init smp_cpus_done(unsigned int max_cpus) 7641195d23SVineet Gupta { 7741195d23SVineet Gupta 7841195d23SVineet Gupta } 7941195d23SVineet Gupta 8041195d23SVineet Gupta /* 8141195d23SVineet Gupta * After power-up, a non Master CPU needs to wait for Master to kick start it 8241195d23SVineet Gupta * 8341195d23SVineet Gupta * The default implementation halts 8441195d23SVineet Gupta * 8541195d23SVineet Gupta * This relies on platform specific support allowing Master to directly set 8641195d23SVineet Gupta * this CPU's PC (to be @first_lines_of_secondary() and kick start it. 8741195d23SVineet Gupta * 8841195d23SVineet Gupta * In lack of such h/w assist, platforms can override this function 8941195d23SVineet Gupta * - make this function busy-spin on a token, eventually set by Master 9041195d23SVineet Gupta * (from arc_platform_smp_wakeup_cpu()) 9141195d23SVineet Gupta * - Once token is available, jump to @first_lines_of_secondary 9241195d23SVineet Gupta * (using inline asm). 9341195d23SVineet Gupta * 9441195d23SVineet Gupta * Alert: can NOT use stack here as it has not been determined/setup for CPU. 9541195d23SVineet Gupta * If it turns out to be elaborate, it's better to code it in assembly 9641195d23SVineet Gupta * 9741195d23SVineet Gupta */ 98064a6269SVineet Gupta void __weak arc_platform_smp_wait_to_boot(int cpu) 9941195d23SVineet Gupta { 10041195d23SVineet Gupta /* 10141195d23SVineet Gupta * As a hack for debugging - since debugger will single-step over the 10241195d23SVineet Gupta * FLAG insn - wrap the halt itself it in a self loop 10341195d23SVineet Gupta */ 10441195d23SVineet Gupta __asm__ __volatile__( 10541195d23SVineet Gupta "1: \n" 10641195d23SVineet Gupta " flag 1 \n" 10741195d23SVineet Gupta " b 1b \n"); 10841195d23SVineet Gupta } 10941195d23SVineet Gupta 11010b12718SVineet Gupta const char *arc_platform_smp_cpuinfo(void) 11110b12718SVineet Gupta { 11210b12718SVineet Gupta return plat_smp_ops.info; 11310b12718SVineet Gupta } 11410b12718SVineet Gupta 11541195d23SVineet Gupta /* 11641195d23SVineet Gupta * The very first "C" code executed by secondary 11741195d23SVineet Gupta * Called from asm stub in head.S 11841195d23SVineet Gupta * "current"/R25 already setup by low level boot code 11941195d23SVineet Gupta */ 120ce759956SPaul Gortmaker void start_kernel_secondary(void) 12141195d23SVineet Gupta { 12241195d23SVineet Gupta struct mm_struct *mm = &init_mm; 12341195d23SVineet Gupta unsigned int cpu = smp_processor_id(); 12441195d23SVineet Gupta 12541195d23SVineet Gupta /* MMU, Caches, Vector Table, Interrupts etc */ 12641195d23SVineet Gupta setup_processor(); 12741195d23SVineet Gupta 12841195d23SVineet Gupta atomic_inc(&mm->mm_users); 12941195d23SVineet Gupta atomic_inc(&mm->mm_count); 13041195d23SVineet Gupta current->active_mm = mm; 1315ea72a90SVineet Gupta cpumask_set_cpu(cpu, mm_cpumask(mm)); 13241195d23SVineet Gupta 13341195d23SVineet Gupta notify_cpu_starting(cpu); 13441195d23SVineet Gupta set_cpu_online(cpu, true); 13541195d23SVineet Gupta 13641195d23SVineet Gupta pr_info("## CPU%u LIVE ##: Executing Code...\n", cpu); 13741195d23SVineet Gupta 13803a6d28cSVineet Gupta if (machine_desc->init_smp) 13903a6d28cSVineet Gupta machine_desc->init_smp(smp_processor_id()); 14041195d23SVineet Gupta 14141195d23SVineet Gupta arc_local_timer_setup(cpu); 14241195d23SVineet Gupta 14341195d23SVineet Gupta local_irq_enable(); 14441195d23SVineet Gupta preempt_disable(); 145fa35e42aSThomas Gleixner cpu_startup_entry(CPUHP_ONLINE); 14641195d23SVineet Gupta } 14741195d23SVineet Gupta 14841195d23SVineet Gupta /* 14941195d23SVineet Gupta * Called from kernel_init( ) -> smp_init( ) - for each CPU 15041195d23SVineet Gupta * 15141195d23SVineet Gupta * At this point, Secondary Processor is "HALT"ed: 15241195d23SVineet Gupta * -It booted, but was halted in head.S 15341195d23SVineet Gupta * -It was configured to halt-on-reset 15441195d23SVineet Gupta * So need to wake it up. 15541195d23SVineet Gupta * 15641195d23SVineet Gupta * Essential requirements being where to run from (PC) and stack (SP) 15741195d23SVineet Gupta */ 158ce759956SPaul Gortmaker int __cpu_up(unsigned int cpu, struct task_struct *idle) 15941195d23SVineet Gupta { 16041195d23SVineet Gupta unsigned long wait_till; 16141195d23SVineet Gupta 16241195d23SVineet Gupta secondary_idle_tsk = idle; 16341195d23SVineet Gupta 16441195d23SVineet Gupta pr_info("Idle Task [%d] %p", cpu, idle); 16541195d23SVineet Gupta pr_info("Trying to bring up CPU%u ...\n", cpu); 16641195d23SVineet Gupta 16710b12718SVineet Gupta if (plat_smp_ops.cpu_kick) 16810b12718SVineet Gupta plat_smp_ops.cpu_kick(cpu, 16941195d23SVineet Gupta (unsigned long)first_lines_of_secondary); 17041195d23SVineet Gupta 17141195d23SVineet Gupta /* wait for 1 sec after kicking the secondary */ 17241195d23SVineet Gupta wait_till = jiffies + HZ; 17341195d23SVineet Gupta while (time_before(jiffies, wait_till)) { 17441195d23SVineet Gupta if (cpu_online(cpu)) 17541195d23SVineet Gupta break; 17641195d23SVineet Gupta } 17741195d23SVineet Gupta 17841195d23SVineet Gupta if (!cpu_online(cpu)) { 17941195d23SVineet Gupta pr_info("Timeout: CPU%u FAILED to comeup !!!\n", cpu); 18041195d23SVineet Gupta return -1; 18141195d23SVineet Gupta } 18241195d23SVineet Gupta 18341195d23SVineet Gupta secondary_idle_tsk = NULL; 18441195d23SVineet Gupta 18541195d23SVineet Gupta return 0; 18641195d23SVineet Gupta } 18741195d23SVineet Gupta 18841195d23SVineet Gupta /* 18941195d23SVineet Gupta * not supported here 19041195d23SVineet Gupta */ 19141195d23SVineet Gupta int __init setup_profiling_timer(unsigned int multiplier) 19241195d23SVineet Gupta { 19341195d23SVineet Gupta return -EINVAL; 19441195d23SVineet Gupta } 19541195d23SVineet Gupta 19641195d23SVineet Gupta /*****************************************************************************/ 19741195d23SVineet Gupta /* Inter Processor Interrupt Handling */ 19841195d23SVineet Gupta /*****************************************************************************/ 19941195d23SVineet Gupta 20041195d23SVineet Gupta /* 20141195d23SVineet Gupta * structures for inter-processor calls 20241195d23SVineet Gupta * A Collection of single bit ipi messages 20341195d23SVineet Gupta * 20441195d23SVineet Gupta */ 20541195d23SVineet Gupta 20641195d23SVineet Gupta /* 20741195d23SVineet Gupta * TODO_rajesh investigate tlb message types. 20841195d23SVineet Gupta * IPI Timer not needed because each ARC has an individual Interrupting Timer 20941195d23SVineet Gupta */ 21041195d23SVineet Gupta enum ipi_msg_type { 21141195d23SVineet Gupta IPI_NOP = 0, 21241195d23SVineet Gupta IPI_RESCHEDULE = 1, 21341195d23SVineet Gupta IPI_CALL_FUNC, 21441195d23SVineet Gupta IPI_CPU_STOP 21541195d23SVineet Gupta }; 21641195d23SVineet Gupta 21741195d23SVineet Gupta struct ipi_data { 21841195d23SVineet Gupta unsigned long bits; 21941195d23SVineet Gupta }; 22041195d23SVineet Gupta 22141195d23SVineet Gupta static DEFINE_PER_CPU(struct ipi_data, ipi_data); 22241195d23SVineet Gupta 223ddf84433SVineet Gupta static void ipi_send_msg_one(int cpu, enum ipi_msg_type msg) 22441195d23SVineet Gupta { 225ddf84433SVineet Gupta struct ipi_data *ipi = &per_cpu(ipi_data, cpu); 22641195d23SVineet Gupta unsigned long flags; 22741195d23SVineet Gupta 22841195d23SVineet Gupta local_irq_save(flags); 22941195d23SVineet Gupta 23041195d23SVineet Gupta set_bit(msg, &ipi->bits); 23141195d23SVineet Gupta 23241195d23SVineet Gupta /* Call the platform specific cross-CPU call function */ 23310b12718SVineet Gupta if (plat_smp_ops.ipi_send) 234ddf84433SVineet Gupta plat_smp_ops.ipi_send(cpu); 23541195d23SVineet Gupta 23641195d23SVineet Gupta local_irq_restore(flags); 23741195d23SVineet Gupta } 23841195d23SVineet Gupta 239ddf84433SVineet Gupta static void ipi_send_msg(const struct cpumask *callmap, enum ipi_msg_type msg) 240ddf84433SVineet Gupta { 241ddf84433SVineet Gupta unsigned int cpu; 242ddf84433SVineet Gupta 243ddf84433SVineet Gupta for_each_cpu(cpu, callmap) 244ddf84433SVineet Gupta ipi_send_msg_one(cpu, msg); 245ddf84433SVineet Gupta } 246ddf84433SVineet Gupta 24741195d23SVineet Gupta void smp_send_reschedule(int cpu) 24841195d23SVineet Gupta { 249ddf84433SVineet Gupta ipi_send_msg_one(cpu, IPI_RESCHEDULE); 25041195d23SVineet Gupta } 25141195d23SVineet Gupta 25241195d23SVineet Gupta void smp_send_stop(void) 25341195d23SVineet Gupta { 25441195d23SVineet Gupta struct cpumask targets; 25541195d23SVineet Gupta cpumask_copy(&targets, cpu_online_mask); 25641195d23SVineet Gupta cpumask_clear_cpu(smp_processor_id(), &targets); 25741195d23SVineet Gupta ipi_send_msg(&targets, IPI_CPU_STOP); 25841195d23SVineet Gupta } 25941195d23SVineet Gupta 26041195d23SVineet Gupta void arch_send_call_function_single_ipi(int cpu) 26141195d23SVineet Gupta { 262ddf84433SVineet Gupta ipi_send_msg_one(cpu, IPI_CALL_FUNC); 26341195d23SVineet Gupta } 26441195d23SVineet Gupta 26541195d23SVineet Gupta void arch_send_call_function_ipi_mask(const struct cpumask *mask) 26641195d23SVineet Gupta { 26741195d23SVineet Gupta ipi_send_msg(mask, IPI_CALL_FUNC); 26841195d23SVineet Gupta } 26941195d23SVineet Gupta 27041195d23SVineet Gupta /* 27141195d23SVineet Gupta * ipi_cpu_stop - handle IPI from smp_send_stop() 27241195d23SVineet Gupta */ 27341195d23SVineet Gupta static void ipi_cpu_stop(unsigned int cpu) 27441195d23SVineet Gupta { 27541195d23SVineet Gupta machine_halt(); 27641195d23SVineet Gupta } 27741195d23SVineet Gupta 27841195d23SVineet Gupta static inline void __do_IPI(unsigned long *ops, struct ipi_data *ipi, int cpu) 27941195d23SVineet Gupta { 28041195d23SVineet Gupta unsigned long msg = 0; 28141195d23SVineet Gupta 28241195d23SVineet Gupta do { 28341195d23SVineet Gupta msg = find_next_bit(ops, BITS_PER_LONG, msg+1); 28441195d23SVineet Gupta 28541195d23SVineet Gupta switch (msg) { 28641195d23SVineet Gupta case IPI_RESCHEDULE: 28741195d23SVineet Gupta scheduler_ipi(); 28841195d23SVineet Gupta break; 28941195d23SVineet Gupta 29041195d23SVineet Gupta case IPI_CALL_FUNC: 29141195d23SVineet Gupta generic_smp_call_function_interrupt(); 29241195d23SVineet Gupta break; 29341195d23SVineet Gupta 29441195d23SVineet Gupta case IPI_CPU_STOP: 29541195d23SVineet Gupta ipi_cpu_stop(cpu); 29641195d23SVineet Gupta break; 29741195d23SVineet Gupta } 29841195d23SVineet Gupta } while (msg < BITS_PER_LONG); 29941195d23SVineet Gupta 30041195d23SVineet Gupta } 30141195d23SVineet Gupta 30241195d23SVineet Gupta /* 30341195d23SVineet Gupta * arch-common ISR to handle for inter-processor interrupts 30441195d23SVineet Gupta * Has hooks for platform specific IPI 30541195d23SVineet Gupta */ 30641195d23SVineet Gupta irqreturn_t do_IPI(int irq, void *dev_id) 30741195d23SVineet Gupta { 30841195d23SVineet Gupta int cpu = smp_processor_id(); 30941195d23SVineet Gupta struct ipi_data *ipi = &per_cpu(ipi_data, cpu); 31041195d23SVineet Gupta unsigned long ops; 31141195d23SVineet Gupta 31210b12718SVineet Gupta if (plat_smp_ops.ipi_clear) 31310b12718SVineet Gupta plat_smp_ops.ipi_clear(cpu, irq); 31441195d23SVineet Gupta 31541195d23SVineet Gupta /* 31641195d23SVineet Gupta * XXX: is this loop really needed 31741195d23SVineet Gupta * And do we need to move ipi_clean inside 31841195d23SVineet Gupta */ 31941195d23SVineet Gupta while ((ops = xchg(&ipi->bits, 0)) != 0) 32041195d23SVineet Gupta __do_IPI(&ops, ipi, cpu); 32141195d23SVineet Gupta 32241195d23SVineet Gupta return IRQ_HANDLED; 32341195d23SVineet Gupta } 32441195d23SVineet Gupta 32541195d23SVineet Gupta /* 32641195d23SVineet Gupta * API called by platform code to hookup arch-common ISR to their IPI IRQ 32741195d23SVineet Gupta */ 32841195d23SVineet Gupta static DEFINE_PER_CPU(int, ipi_dev); 32941195d23SVineet Gupta int smp_ipi_irq_setup(int cpu, int irq) 33041195d23SVineet Gupta { 33141195d23SVineet Gupta int *dev_id = &per_cpu(ipi_dev, smp_processor_id()); 33241195d23SVineet Gupta return request_percpu_irq(irq, do_IPI, "IPI Interrupt", dev_id); 33341195d23SVineet Gupta } 334