xref: /kvm-unit-tests/lib/x86/apic.c (revision 0f187a08902cc2d1a4ddf0ffe45959b0ffa4db8c)
1 #include "libcflat.h"
2 #include "apic.h"
3 #include "msr.h"
4 
5 static void *g_apic = (void *)0xfee00000;
6 static void *g_ioapic = (void *)0xfec00000;
7 
8 struct apic_ops {
9     u32 (*reg_read)(unsigned reg);
10     void (*reg_write)(unsigned reg, u32 val);
11     void (*icr_write)(u32 val, u32 dest);
12     u32 (*id)(void);
13 };
14 
15 static void outb(unsigned char data, unsigned short port)
16 {
17     asm volatile ("out %0, %1" : : "a"(data), "d"(port));
18 }
19 
20 void eoi(void)
21 {
22     apic_write(APIC_EOI, 0);
23 }
24 
25 static u32 xapic_read(unsigned reg)
26 {
27     return *(volatile u32 *)(g_apic + reg);
28 }
29 
30 static void xapic_write(unsigned reg, u32 val)
31 {
32     *(volatile u32 *)(g_apic + reg) = val;
33 }
34 
35 static void xapic_icr_write(u32 val, u32 dest)
36 {
37     while (xapic_read(APIC_ICR) & APIC_ICR_BUSY)
38         ;
39     xapic_write(APIC_ICR2, dest << 24);
40     xapic_write(APIC_ICR, val);
41 }
42 
43 static uint32_t xapic_id(void)
44 {
45     return xapic_read(APIC_ID) >> 24;
46 }
47 
48 static const struct apic_ops xapic_ops = {
49     .reg_read = xapic_read,
50     .reg_write = xapic_write,
51     .icr_write = xapic_icr_write,
52     .id = xapic_id,
53 };
54 
55 static const struct apic_ops *apic_ops = &xapic_ops;
56 
57 static u32 x2apic_read(unsigned reg)
58 {
59     unsigned a, d;
60 
61     asm volatile ("rdmsr" : "=a"(a), "=d"(d) : "c"(APIC_BASE_MSR + reg/16));
62     return a | (u64)d << 32;
63 }
64 
65 static void x2apic_write(unsigned reg, u32 val)
66 {
67     asm volatile ("wrmsr" : : "a"(val), "d"(0), "c"(APIC_BASE_MSR + reg/16));
68 }
69 
70 static void x2apic_icr_write(u32 val, u32 dest)
71 {
72     asm volatile ("wrmsr" : : "a"(val), "d"(dest),
73                   "c"(APIC_BASE_MSR + APIC_ICR/16));
74 }
75 
76 static uint32_t x2apic_id(void)
77 {
78     return x2apic_read(APIC_ID);
79 }
80 
81 static const struct apic_ops x2apic_ops = {
82     .reg_read = x2apic_read,
83     .reg_write = x2apic_write,
84     .icr_write = x2apic_icr_write,
85     .id = x2apic_id,
86 };
87 
88 u32 apic_read(unsigned reg)
89 {
90     return apic_ops->reg_read(reg);
91 }
92 
93 void apic_write(unsigned reg, u32 val)
94 {
95     apic_ops->reg_write(reg, val);
96 }
97 
98 void apic_icr_write(u32 val, u32 dest)
99 {
100     apic_ops->icr_write(val, dest);
101 }
102 
103 uint32_t apic_id(void)
104 {
105     return apic_ops->id();
106 }
107 
108 int enable_x2apic(void)
109 {
110     unsigned a, b, c, d;
111 
112     asm ("cpuid" : "=a"(a), "=b"(b), "=c"(c), "=d"(d) : "0"(1));
113 
114     if (c & (1 << 21)) {
115         asm ("rdmsr" : "=a"(a), "=d"(d) : "c"(MSR_IA32_APICBASE));
116         a |= 1 << 10;
117         asm ("wrmsr" : : "a"(a), "d"(d), "c"(MSR_IA32_APICBASE));
118         apic_ops = &x2apic_ops;
119         return 1;
120     } else {
121         return 0;
122     }
123 }
124 
125 u32 ioapic_read_reg(unsigned reg)
126 {
127     *(volatile u32 *)g_ioapic = reg;
128     return *(volatile u32 *)(g_ioapic + 0x10);
129 }
130 
131 void ioapic_write_reg(unsigned reg, u32 value)
132 {
133     *(volatile u32 *)g_ioapic = reg;
134     *(volatile u32 *)(g_ioapic + 0x10) = value;
135 }
136 
137 void ioapic_write_redir(unsigned line, ioapic_redir_entry_t e)
138 {
139     ioapic_write_reg(0x10 + line * 2 + 0, ((u32 *)&e)[0]);
140     ioapic_write_reg(0x10 + line * 2 + 1, ((u32 *)&e)[1]);
141 }
142 
143 ioapic_redir_entry_t ioapic_read_redir(unsigned line)
144 {
145     ioapic_redir_entry_t e;
146 
147     ((u32 *)&e)[0] = ioapic_read_reg(0x10 + line * 2 + 0);
148     ((u32 *)&e)[1] = ioapic_read_reg(0x10 + line * 2 + 1);
149     return e;
150 
151 }
152 
153 void set_mask(unsigned line, int mask)
154 {
155     ioapic_redir_entry_t e = ioapic_read_redir(line);
156 
157     e.mask = mask;
158     ioapic_write_redir(line, e);
159 }
160 
161 void enable_apic(void)
162 {
163     printf("enabling apic\n");
164     xapic_write(0xf0, 0x1ff); /* spurious vector register */
165 }
166 
167 void mask_pic_interrupts(void)
168 {
169     outb(0xff, 0x21);
170     outb(0xff, 0xa1);
171 }
172