1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * From coreboot file of same name
4 *
5 * Copyright (C) 2008-2009 coresystems GmbH
6 * Copyright (C) 2014 Google, Inc
7 */
8
9 #include <common.h>
10 #include <log.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
lapic_read(unsigned long reg)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 */
__xchg(unsigned long x,volatile void * ptr,int size)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
lapic_write(unsigned long reg,unsigned long v)61 void lapic_write(unsigned long reg, unsigned long v)
62 {
63 (void)xchg((volatile unsigned long *)(LAPIC_DEFAULT_BASE + reg), v);
64 }
65
enable_lapic(void)66 void enable_lapic(void)
67 {
68 if (!IS_ENABLED(CONFIG_INTEL_QUARK)) {
69 msr_t msr;
70
71 msr = msr_read(MSR_IA32_APICBASE);
72 msr.hi &= 0xffffff00;
73 msr.lo |= MSR_IA32_APICBASE_ENABLE;
74 msr.lo &= ~MSR_IA32_APICBASE_BASE;
75 msr.lo |= LAPIC_DEFAULT_BASE;
76 msr_write(MSR_IA32_APICBASE, msr);
77 }
78 }
79
disable_lapic(void)80 void disable_lapic(void)
81 {
82 if (!IS_ENABLED(CONFIG_INTEL_QUARK)) {
83 msr_t msr;
84
85 msr = msr_read(MSR_IA32_APICBASE);
86 msr.lo &= ~MSR_IA32_APICBASE_ENABLE;
87 msr_write(MSR_IA32_APICBASE, msr);
88 }
89 }
90
lapicid(void)91 unsigned long lapicid(void)
92 {
93 return lapic_read(LAPIC_ID) >> 24;
94 }
95
lapic_wait_icr_idle(void)96 static void lapic_wait_icr_idle(void)
97 {
98 do { } while (lapic_read(LAPIC_ICR) & LAPIC_ICR_BUSY);
99 }
100
lapic_remote_read(int apicid,int reg,unsigned long * pvalue)101 int lapic_remote_read(int apicid, int reg, unsigned long *pvalue)
102 {
103 int timeout;
104 unsigned long status;
105 int result;
106
107 lapic_wait_icr_idle();
108 lapic_write(LAPIC_ICR2, SET_LAPIC_DEST_FIELD(apicid));
109 lapic_write(LAPIC_ICR, LAPIC_DM_REMRD | (reg >> 4));
110
111 timeout = 0;
112 do {
113 status = lapic_read(LAPIC_ICR) & LAPIC_ICR_RR_MASK;
114 } while (status == LAPIC_ICR_RR_INPROG && timeout++ < 1000);
115
116 result = -1;
117 if (status == LAPIC_ICR_RR_VALID) {
118 *pvalue = lapic_read(LAPIC_RRR);
119 result = 0;
120 }
121
122 return result;
123 }
124
lapic_setup(void)125 void lapic_setup(void)
126 {
127 /* Only Pentium Pro and later have those MSR stuff */
128 debug("Setting up local apic: ");
129
130 /* Enable the local apic */
131 enable_lapic();
132
133 /* Set Task Priority to 'accept all' */
134 lapic_write(LAPIC_TASKPRI,
135 lapic_read(LAPIC_TASKPRI) & ~LAPIC_TPRI_MASK);
136
137 /* Put the local apic in virtual wire mode */
138 lapic_write(LAPIC_SPIV, (lapic_read(LAPIC_SPIV) &
139 ~(LAPIC_VECTOR_MASK)) | LAPIC_SPIV_ENABLE);
140 lapic_write(LAPIC_LVT0, (lapic_read(LAPIC_LVT0) &
141 ~(LAPIC_LVT_MASKED | LAPIC_LVT_LEVEL_TRIGGER |
142 LAPIC_LVT_REMOTE_IRR | LAPIC_INPUT_POLARITY |
143 LAPIC_SEND_PENDING | LAPIC_LVT_RESERVED_1 |
144 LAPIC_DELIVERY_MODE_MASK)) |
145 (LAPIC_LVT_REMOTE_IRR | LAPIC_SEND_PENDING |
146 LAPIC_DELIVERY_MODE_EXTINT));
147 lapic_write(LAPIC_LVT1, (lapic_read(LAPIC_LVT1) &
148 ~(LAPIC_LVT_MASKED | LAPIC_LVT_LEVEL_TRIGGER |
149 LAPIC_LVT_REMOTE_IRR | LAPIC_INPUT_POLARITY |
150 LAPIC_SEND_PENDING | LAPIC_LVT_RESERVED_1 |
151 LAPIC_DELIVERY_MODE_MASK)) |
152 (LAPIC_LVT_REMOTE_IRR | LAPIC_SEND_PENDING |
153 LAPIC_DELIVERY_MODE_NMI));
154
155 debug("apic_id: 0x%02lx, ", lapicid());
156
157 debug("done.\n");
158 post_code(POST_LAPIC);
159 }
160