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/config.h> 12 #include <linux/kernel.h> 13 #include <linux/sched.h> 14 #include <linux/smp.h> 15 #include <linux/smp_lock.h> 16 #include <linux/interrupt.h> 17 #include <linux/kernel_stat.h> 18 #include <linux/delay.h> 19 #include <linux/init.h> 20 #include <linux/spinlock.h> 21 22 #include <asm/ptrace.h> 23 #include <asm/atomic.h> 24 #include <asm/irq.h> 25 #include <asm/page.h> 26 #include <asm/pgtable.h> 27 #include <asm/sections.h> 28 #include <asm/io.h> 29 #include <asm/prom.h> 30 #include <asm/smp.h> 31 #include <asm/residual.h> 32 #include <asm/time.h> 33 #include <asm/open_pic.h> 34 #include <asm/machdep.h> 35 #include <asm/smp.h> 36 #include <asm/mpic.h> 37 38 static void __devinit smp_chrp_kick_cpu(int nr) 39 { 40 *(unsigned long *)KERNELBASE = nr; 41 asm volatile("dcbf 0,%0"::"r"(KERNELBASE):"memory"); 42 } 43 44 static void __devinit smp_chrp_setup_cpu(int cpu_nr) 45 { 46 mpic_setup_this_cpu(); 47 } 48 49 static DEFINE_SPINLOCK(timebase_lock); 50 static unsigned int timebase_upper = 0, timebase_lower = 0; 51 52 void __devinit smp_chrp_give_timebase(void) 53 { 54 spin_lock(&timebase_lock); 55 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); 56 timebase_upper = get_tbu(); 57 timebase_lower = get_tbl(); 58 spin_unlock(&timebase_lock); 59 60 while (timebase_upper || timebase_lower) 61 barrier(); 62 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); 63 } 64 65 void __devinit smp_chrp_take_timebase(void) 66 { 67 while (!(timebase_upper || timebase_lower)) 68 barrier(); 69 spin_lock(&timebase_lock); 70 set_tb(timebase_upper, timebase_lower); 71 timebase_upper = 0; 72 timebase_lower = 0; 73 spin_unlock(&timebase_lock); 74 printk("CPU %i taken timebase\n", smp_processor_id()); 75 } 76 77 /* CHRP with openpic */ 78 struct smp_ops_t chrp_smp_ops = { 79 .message_pass = smp_mpic_message_pass, 80 .probe = smp_mpic_probe, 81 .kick_cpu = smp_chrp_kick_cpu, 82 .setup_cpu = smp_chrp_setup_cpu, 83 .give_timebase = smp_chrp_give_timebase, 84 .take_timebase = smp_chrp_take_timebase, 85 }; 86