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/residual.h> 30 #include <asm/time.h> 31 #include <asm/machdep.h> 32 #include <asm/mpic.h> 33 #include <asm/rtas.h> 34 35 static void __devinit smp_chrp_kick_cpu(int nr) 36 { 37 *(unsigned long *)KERNELBASE = nr; 38 asm volatile("dcbf 0,%0"::"r"(KERNELBASE):"memory"); 39 } 40 41 static void __devinit smp_chrp_setup_cpu(int cpu_nr) 42 { 43 mpic_setup_this_cpu(); 44 } 45 46 static DEFINE_SPINLOCK(timebase_lock); 47 static unsigned int timebase_upper = 0, timebase_lower = 0; 48 49 void __devinit smp_chrp_give_timebase(void) 50 { 51 spin_lock(&timebase_lock); 52 rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL); 53 timebase_upper = get_tbu(); 54 timebase_lower = get_tbl(); 55 spin_unlock(&timebase_lock); 56 57 while (timebase_upper || timebase_lower) 58 barrier(); 59 rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL); 60 } 61 62 void __devinit smp_chrp_take_timebase(void) 63 { 64 while (!(timebase_upper || timebase_lower)) 65 barrier(); 66 spin_lock(&timebase_lock); 67 set_tb(timebase_upper, timebase_lower); 68 timebase_upper = 0; 69 timebase_lower = 0; 70 spin_unlock(&timebase_lock); 71 printk("CPU %i taken timebase\n", smp_processor_id()); 72 } 73 74 /* CHRP with openpic */ 75 struct smp_ops_t chrp_smp_ops = { 76 .message_pass = smp_mpic_message_pass, 77 .probe = smp_mpic_probe, 78 .kick_cpu = smp_chrp_kick_cpu, 79 .setup_cpu = smp_chrp_setup_cpu, 80 .give_timebase = smp_chrp_give_timebase, 81 .take_timebase = smp_chrp_take_timebase, 82 }; 83