1 /* 2 * SH-X3 SMP 3 * 4 * Copyright (C) 2007 - 2010 Paul Mundt 5 * Copyright (C) 2007 Magnus Damm 6 * 7 * This file is subject to the terms and conditions of the GNU General Public 8 * License. See the file "COPYING" in the main directory of this archive 9 * for more details. 10 */ 11 #include <linux/init.h> 12 #include <linux/kernel.h> 13 #include <linux/cpumask.h> 14 #include <linux/smp.h> 15 #include <linux/interrupt.h> 16 #include <linux/io.h> 17 #include <linux/sched.h> 18 #include <linux/delay.h> 19 #include <linux/cpu.h> 20 #include <asm/sections.h> 21 22 #define STBCR_REG(phys_id) (0xfe400004 | (phys_id << 12)) 23 #define RESET_REG(phys_id) (0xfe400008 | (phys_id << 12)) 24 25 #define STBCR_MSTP 0x00000001 26 #define STBCR_RESET 0x00000002 27 #define STBCR_SLEEP 0x00000004 28 #define STBCR_LTSLP 0x80000000 29 30 static irqreturn_t ipi_interrupt_handler(int irq, void *arg) 31 { 32 unsigned int message = (unsigned int)(long)arg; 33 unsigned int cpu = hard_smp_processor_id(); 34 unsigned int offs = 4 * cpu; 35 unsigned int x; 36 37 x = __raw_readl(0xfe410070 + offs); /* C0INITICI..CnINTICI */ 38 x &= (1 << (message << 2)); 39 __raw_writel(x, 0xfe410080 + offs); /* C0INTICICLR..CnINTICICLR */ 40 41 smp_message_recv(message); 42 43 return IRQ_HANDLED; 44 } 45 46 static void shx3_smp_setup(void) 47 { 48 unsigned int cpu = 0; 49 int i, num; 50 51 init_cpu_possible(cpumask_of(cpu)); 52 53 /* Enable light sleep for the boot CPU */ 54 __raw_writel(__raw_readl(STBCR_REG(cpu)) | STBCR_LTSLP, STBCR_REG(cpu)); 55 56 __cpu_number_map[0] = 0; 57 __cpu_logical_map[0] = 0; 58 59 /* 60 * Do this stupidly for now.. we don't have an easy way to probe 61 * for the total number of cores. 62 */ 63 for (i = 1, num = 0; i < NR_CPUS; i++) { 64 set_cpu_possible(i, true); 65 __cpu_number_map[i] = ++num; 66 __cpu_logical_map[num] = i; 67 } 68 69 printk(KERN_INFO "Detected %i available secondary CPU(s)\n", num); 70 } 71 72 static void shx3_prepare_cpus(unsigned int max_cpus) 73 { 74 int i; 75 76 BUILD_BUG_ON(SMP_MSG_NR >= 8); 77 78 for (i = 0; i < SMP_MSG_NR; i++) 79 request_irq(104 + i, ipi_interrupt_handler, 80 IRQF_PERCPU, "IPI", (void *)(long)i); 81 82 for (i = 0; i < max_cpus; i++) 83 set_cpu_present(i, true); 84 } 85 86 static void shx3_start_cpu(unsigned int cpu, unsigned long entry_point) 87 { 88 if (__in_29bit_mode()) 89 __raw_writel(entry_point, RESET_REG(cpu)); 90 else 91 __raw_writel(virt_to_phys(entry_point), RESET_REG(cpu)); 92 93 if (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP)) 94 __raw_writel(STBCR_MSTP, STBCR_REG(cpu)); 95 96 while (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP)) 97 cpu_relax(); 98 99 /* Start up secondary processor by sending a reset */ 100 __raw_writel(STBCR_RESET | STBCR_LTSLP, STBCR_REG(cpu)); 101 } 102 103 static unsigned int shx3_smp_processor_id(void) 104 { 105 return __raw_readl(0xff000048); /* CPIDR */ 106 } 107 108 static void shx3_send_ipi(unsigned int cpu, unsigned int message) 109 { 110 unsigned long addr = 0xfe410070 + (cpu * 4); 111 112 BUG_ON(cpu >= 4); 113 114 __raw_writel(1 << (message << 2), addr); /* C0INTICI..CnINTICI */ 115 } 116 117 static void shx3_update_boot_vector(unsigned int cpu) 118 { 119 __raw_writel(STBCR_MSTP, STBCR_REG(cpu)); 120 while (!(__raw_readl(STBCR_REG(cpu)) & STBCR_MSTP)) 121 cpu_relax(); 122 __raw_writel(STBCR_RESET, STBCR_REG(cpu)); 123 } 124 125 static int 126 shx3_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) 127 { 128 unsigned int cpu = (unsigned int)hcpu; 129 130 switch (action) { 131 case CPU_UP_PREPARE: 132 shx3_update_boot_vector(cpu); 133 break; 134 case CPU_ONLINE: 135 pr_info("CPU %u is now online\n", cpu); 136 break; 137 case CPU_DEAD: 138 break; 139 } 140 141 return NOTIFY_OK; 142 } 143 144 static struct notifier_block shx3_cpu_notifier = { 145 .notifier_call = shx3_cpu_callback, 146 }; 147 148 static int register_shx3_cpu_notifier(void) 149 { 150 register_hotcpu_notifier(&shx3_cpu_notifier); 151 return 0; 152 } 153 late_initcall(register_shx3_cpu_notifier); 154 155 struct plat_smp_ops shx3_smp_ops = { 156 .smp_setup = shx3_smp_setup, 157 .prepare_cpus = shx3_prepare_cpus, 158 .start_cpu = shx3_start_cpu, 159 .smp_processor_id = shx3_smp_processor_id, 160 .send_ipi = shx3_send_ipi, 161 .cpu_die = native_cpu_die, 162 .cpu_disable = native_cpu_disable, 163 .play_dead = native_play_dead, 164 }; 165