1 /* 2 * Smp support for CHRP machines. 3 * 4 * Written by Cort Dougan (cort@cs.nmt.edu) borrowing a great 5 * deal of code from the sparc and intel versions. 6 * 7 * Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu> 8 * 9 */ 10 11 #include <linux/kernel.h> 12 #include <linux/sched.h> 13 #include <linux/smp.h> 14 #include <linux/interrupt.h> 15 #include <linux/kernel_stat.h> 16 #include <linux/delay.h> 17 #include <linux/init.h> 18 #include <linux/spinlock.h> 19 20 #include <asm/ptrace.h> 21 #include <asm/atomic.h> 22 #include <asm/irq.h> 23 #include <asm/page.h> 24 #include <asm/pgtable.h> 25 #include <asm/sections.h> 26 #include <asm/io.h> 27 #include <asm/prom.h> 28 #include <asm/smp.h> 29 #include <asm/time.h> 30 #include <asm/machdep.h> 31 #include <asm/mpic.h> 32 #include <asm/rtas.h> 33 34 static void __devinit smp_chrp_kick_cpu(int nr) 35 { 36 *(unsigned long *)KERNELBASE = nr; 37 asm volatile("dcbf 0,%0"::"r"(KERNELBASE):"memory"); 38 } 39 40 static void __devinit smp_chrp_setup_cpu(int cpu_nr) 41 { 42 mpic_setup_this_cpu(); 43 } 44 45 static DEFINE_SPINLOCK(timebase_lock); 46 static unsigned int timebase_upper = 0, timebase_lower = 0; 47 48 void __devinit smp_chrp_give_timebase(void) 49 { 50 spin_lock(&timebase_lock); 51 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); 52 timebase_upper = get_tbu(); 53 timebase_lower = get_tbl(); 54 spin_unlock(&timebase_lock); 55 56 while (timebase_upper || timebase_lower) 57 barrier(); 58 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); 59 } 60 61 void __devinit smp_chrp_take_timebase(void) 62 { 63 while (!(timebase_upper || timebase_lower)) 64 barrier(); 65 spin_lock(&timebase_lock); 66 set_tb(timebase_upper, timebase_lower); 67 timebase_upper = 0; 68 timebase_lower = 0; 69 spin_unlock(&timebase_lock); 70 printk("CPU %i taken timebase\n", smp_processor_id()); 71 } 72 73 /* CHRP with openpic */ 74 struct smp_ops_t chrp_smp_ops = { 75 .message_pass = smp_mpic_message_pass, 76 .probe = smp_mpic_probe, 77 .kick_cpu = smp_chrp_kick_cpu, 78 .setup_cpu = smp_chrp_setup_cpu, 79 .give_timebase = smp_chrp_give_timebase, 80 .take_timebase = smp_chrp_take_timebase, 81 }; 82