1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * CBE Pervasive Monitor and Debug 4 * 5 * (C) Copyright IBM Corporation 2005 6 * 7 * Authors: Maximino Aguilar (maguilar@us.ibm.com) 8 * Michael N. Day (mnday@us.ibm.com) 9 */ 10 11 #undef DEBUG 12 13 #include <linux/interrupt.h> 14 #include <linux/irq.h> 15 #include <linux/percpu.h> 16 #include <linux/types.h> 17 #include <linux/kallsyms.h> 18 #include <linux/pgtable.h> 19 20 #include <asm/io.h> 21 #include <asm/machdep.h> 22 #include <asm/prom.h> 23 #include <asm/reg.h> 24 #include <asm/cell-regs.h> 25 #include <asm/cpu_has_feature.h> 26 27 #include "pervasive.h" 28 29 static void cbe_power_save(void) 30 { 31 unsigned long ctrl, thread_switch_control; 32 33 /* Ensure our interrupt state is properly tracked */ 34 if (!prep_irq_for_idle()) 35 return; 36 37 ctrl = mfspr(SPRN_CTRLF); 38 39 /* Enable DEC and EE interrupt request */ 40 thread_switch_control = mfspr(SPRN_TSC_CELL); 41 thread_switch_control |= TSC_CELL_EE_ENABLE | TSC_CELL_EE_BOOST; 42 43 switch (ctrl & CTRL_CT) { 44 case CTRL_CT0: 45 thread_switch_control |= TSC_CELL_DEC_ENABLE_0; 46 break; 47 case CTRL_CT1: 48 thread_switch_control |= TSC_CELL_DEC_ENABLE_1; 49 break; 50 default: 51 printk(KERN_WARNING "%s: unknown configuration\n", 52 __func__); 53 break; 54 } 55 mtspr(SPRN_TSC_CELL, thread_switch_control); 56 57 /* 58 * go into low thread priority, medium priority will be 59 * restored for us after wake-up. 60 */ 61 HMT_low(); 62 63 /* 64 * atomically disable thread execution and runlatch. 65 * External and Decrementer exceptions are still handled when the 66 * thread is disabled but now enter in cbe_system_reset_exception() 67 */ 68 ctrl &= ~(CTRL_RUNLATCH | CTRL_TE); 69 mtspr(SPRN_CTRLT, ctrl); 70 71 /* Re-enable interrupts in MSR */ 72 __hard_irq_enable(); 73 } 74 75 static int cbe_system_reset_exception(struct pt_regs *regs) 76 { 77 switch (regs->msr & SRR1_WAKEMASK) { 78 case SRR1_WAKEDEC: 79 set_dec(1); 80 case SRR1_WAKEEE: 81 /* 82 * Handle these when interrupts get re-enabled and we take 83 * them as regular exceptions. We are in an NMI context 84 * and can't handle these here. 85 */ 86 break; 87 case SRR1_WAKEMT: 88 return cbe_sysreset_hack(); 89 #ifdef CONFIG_CBE_RAS 90 case SRR1_WAKESYSERR: 91 cbe_system_error_exception(regs); 92 break; 93 case SRR1_WAKETHERM: 94 cbe_thermal_exception(regs); 95 break; 96 #endif /* CONFIG_CBE_RAS */ 97 default: 98 /* do system reset */ 99 return 0; 100 } 101 /* everything handled */ 102 return 1; 103 } 104 105 void __init cbe_pervasive_init(void) 106 { 107 int cpu; 108 109 if (!cpu_has_feature(CPU_FTR_PAUSE_ZERO)) 110 return; 111 112 for_each_possible_cpu(cpu) { 113 struct cbe_pmd_regs __iomem *regs = cbe_get_cpu_pmd_regs(cpu); 114 if (!regs) 115 continue; 116 117 /* Enable Pause(0) control bit */ 118 out_be64(®s->pmcr, in_be64(®s->pmcr) | 119 CBE_PMD_PAUSE_ZERO_CONTROL); 120 } 121 122 ppc_md.power_save = cbe_power_save; 123 ppc_md.system_reset_exception = cbe_system_reset_exception; 124 } 125