1 /* 2 * From coreboot file of same name 3 * 4 * Copyright (C) 2008-2009 coresystems GmbH 5 * Copyright (C) 2014 Google, Inc 6 * 7 * SPDX-License-Identifier: GPL-2.0 8 */ 9 10 #include <common.h> 11 #include <asm/io.h> 12 #include <asm/lapic.h> 13 #include <asm/msr.h> 14 #include <asm/msr-index.h> 15 #include <asm/post.h> 16 17 unsigned long lapic_read(unsigned long reg) 18 { 19 return readl(LAPIC_DEFAULT_BASE + reg); 20 } 21 22 #define xchg(ptr, v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v), (ptr), \ 23 sizeof(*(ptr)))) 24 25 struct __xchg_dummy { unsigned long a[100]; }; 26 #define __xg(x) ((struct __xchg_dummy *)(x)) 27 28 /* 29 * Note: no "lock" prefix even on SMP. xchg always implies lock anyway. 30 * 31 * Note 2: xchg has side effect, so that attribute volatile is necessary, 32 * but generally the primitive is invalid, *ptr is output argument. 33 */ 34 static inline unsigned long __xchg(unsigned long x, volatile void *ptr, 35 int size) 36 { 37 switch (size) { 38 case 1: 39 __asm__ __volatile__("xchgb %b0,%1" 40 : "=q" (x) 41 : "m" (*__xg(ptr)), "0" (x) 42 : "memory"); 43 break; 44 case 2: 45 __asm__ __volatile__("xchgw %w0,%1" 46 : "=r" (x) 47 : "m" (*__xg(ptr)), "0" (x) 48 : "memory"); 49 break; 50 case 4: 51 __asm__ __volatile__("xchgl %0,%1" 52 : "=r" (x) 53 : "m" (*__xg(ptr)), "0" (x) 54 : "memory"); 55 break; 56 } 57 58 return x; 59 } 60 61 void lapic_write(unsigned long reg, unsigned long v) 62 { 63 (void)xchg((volatile unsigned long *)(LAPIC_DEFAULT_BASE + reg), v); 64 } 65 66 void enable_lapic(void) 67 { 68 msr_t msr; 69 70 msr = msr_read(MSR_IA32_APICBASE); 71 msr.hi &= 0xffffff00; 72 msr.lo |= MSR_IA32_APICBASE_ENABLE; 73 msr.lo &= ~MSR_IA32_APICBASE_BASE; 74 msr.lo |= LAPIC_DEFAULT_BASE; 75 msr_write(MSR_IA32_APICBASE, msr); 76 } 77 78 void disable_lapic(void) 79 { 80 msr_t msr; 81 82 msr = msr_read(MSR_IA32_APICBASE); 83 msr.lo &= ~MSR_IA32_APICBASE_ENABLE; 84 msr_write(MSR_IA32_APICBASE, msr); 85 } 86 87 unsigned long lapicid(void) 88 { 89 return lapic_read(LAPIC_ID) >> 24; 90 } 91 92 static void lapic_wait_icr_idle(void) 93 { 94 do { } while (lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY); 95 } 96 97 int lapic_remote_read(int apicid, int reg, unsigned long *pvalue) 98 { 99 int timeout; 100 unsigned long status; 101 int result; 102 103 lapic_wait_icr_idle(); 104 lapic_write(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid)); 105 lapic_write(LAPIC_ICR, LAPIC_DM_REMRD | (reg >> 4)); 106 107 timeout = 0; 108 do { 109 status = lapic_read(LAPIC_ICR) & LAPIC_ICR_RR_MASK; 110 } while (status == LAPIC_ICR_RR_INPROG && timeout++ < 1000); 111 112 result = -1; 113 if (status == LAPIC_ICR_RR_VALID) { 114 *pvalue = lapic_read(LAPIC_RRR); 115 result = 0; 116 } 117 118 return result; 119 } 120 121 void lapic_setup(void) 122 { 123 #ifdef CONFIG_SMP 124 /* Only Pentium Pro and later have those MSR stuff */ 125 debug("Setting up local apic: "); 126 127 /* Enable the local apic */ 128 enable_lapic(); 129 130 /* Set Task Priority to 'accept all' */ 131 lapic_write(LAPIC_TASKPRI, 132 lapic_read(LAPIC_TASKPRI) & ~LAPIC_TPRI_MASK); 133 134 /* Put the local apic in virtual wire mode */ 135 lapic_write(LAPIC_SPIV, (lapic_read(LAPIC_SPIV) & 136 ~(LAPIC_VECTOR_MASK)) | LAPIC_SPIV_ENABLE); 137 lapic_write(LAPIC_LVT0, (lapic_read(LAPIC_LVT0) & 138 ~(LAPIC_LVT_MASKED | LAPIC_LVT_LEVEL_TRIGGER | 139 LAPIC_LVT_REMOTE_IRR | LAPIC_INPUT_POLARITY | 140 LAPIC_SEND_PENDING | LAPIC_LVT_RESERVED_1 | 141 LAPIC_DELIVERY_MODE_MASK)) | 142 (LAPIC_LVT_REMOTE_IRR | LAPIC_SEND_PENDING | 143 LAPIC_DELIVERY_MODE_EXTINT)); 144 lapic_write(LAPIC_LVT1, (lapic_read(LAPIC_LVT1) & 145 ~(LAPIC_LVT_MASKED | LAPIC_LVT_LEVEL_TRIGGER | 146 LAPIC_LVT_REMOTE_IRR | LAPIC_INPUT_POLARITY | 147 LAPIC_SEND_PENDING | LAPIC_LVT_RESERVED_1 | 148 LAPIC_DELIVERY_MODE_MASK)) | 149 (LAPIC_LVT_REMOTE_IRR | LAPIC_SEND_PENDING | 150 LAPIC_DELIVERY_MODE_NMI)); 151 152 debug("apic_id: 0x%02lx, ", lapicid()); 153 #else /* !CONFIG_SMP */ 154 /* Only Pentium Pro and later have those MSR stuff */ 155 debug("Disabling local apic: "); 156 disable_lapic(); 157 #endif /* CONFIG_SMP */ 158 debug("done.\n"); 159 post_code(POST_LAPIC); 160 } 161