1 /* Copyright 2003 Andi Kleen, SuSE Labs.
2  * Subject to the GNU Public License, v.2
3  *
4  * Generic x86 APIC driver probe layer.
5  */
6 #include <xen/cpumask.h>
7 #include <xen/string.h>
8 #include <xen/kernel.h>
9 #include <xen/ctype.h>
10 #include <xen/init.h>
11 #include <asm/cache.h>
12 #include <asm/fixmap.h>
13 #include <asm/mpspec.h>
14 #include <asm/apicdef.h>
15 #include <asm/mach-generic/mach_apic.h>
16 #include <asm/setup.h>
17 
18 extern const struct genapic apic_bigsmp;
19 
20 const struct genapic *__read_mostly genapic;
21 
22 const struct genapic *apic_probe[] __initdata = {
23 	&apic_bigsmp,
24 	&apic_default,	/* must be last */
25 	NULL,
26 };
27 
28 static bool_t __initdata cmdline_apic;
29 
generic_bigsmp_probe(void)30 void __init generic_bigsmp_probe(void)
31 {
32 	/*
33 	 * This routine is used to switch to bigsmp mode when
34 	 * - There is no apic= option specified by the user
35 	 * - generic_apic_probe() has choosen apic_default as the sub_arch
36 	 * - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support
37 	 */
38 
39 	if (!cmdline_apic && genapic == &apic_default)
40 		if (apic_bigsmp.probe()) {
41 			genapic = &apic_bigsmp;
42 			printk(KERN_INFO "Overriding APIC driver with %s\n",
43 			       genapic->name);
44 		}
45 }
46 
genapic_apic_force(const char * str)47 static int __init genapic_apic_force(const char *str)
48 {
49 	int i, rc = -EINVAL;
50 
51 	for (i = 0; apic_probe[i]; i++)
52 		if (!strcmp(apic_probe[i]->name, str)) {
53 			genapic = apic_probe[i];
54 			rc = 0;
55 		}
56 
57 	return rc;
58 }
59 custom_param("apic", genapic_apic_force);
60 
generic_apic_probe(void)61 void __init generic_apic_probe(void)
62 {
63 	bool changed;
64 	int i;
65 
66 	record_boot_APIC_mode();
67 
68 	check_x2apic_preenabled();
69 	cmdline_apic = changed = (genapic != NULL);
70 
71 	for (i = 0; !changed && apic_probe[i]; i++) {
72 		if (apic_probe[i]->probe()) {
73 			changed = 1;
74 			genapic = apic_probe[i];
75 		}
76 	}
77 	if (!changed)
78 		genapic = &apic_default;
79 
80 	printk(KERN_INFO "Using APIC driver %s\n", genapic->name);
81 }
82 
83 /* These functions can switch the APIC even after the initial ->probe() */
84 
mps_oem_check(struct mp_config_table * mpc,char * oem,char * productid)85 int __init mps_oem_check(struct mp_config_table *mpc, char *oem, char *productid)
86 {
87 	int i;
88 	for (i = 0; apic_probe[i]; ++i) {
89 		if (apic_probe[i]->mps_oem_check(mpc,oem,productid)) {
90 			if (!cmdline_apic) {
91 				genapic = apic_probe[i];
92 				printk(KERN_INFO "Switched to APIC driver `%s'.\n",
93 				       genapic->name);
94 			}
95 			return 1;
96 		}
97 	}
98 	return 0;
99 }
100 
acpi_madt_oem_check(char * oem_id,char * oem_table_id)101 int __init acpi_madt_oem_check(char *oem_id, char *oem_table_id)
102 {
103 	int i;
104 	for (i = 0; apic_probe[i]; ++i) {
105 		if (apic_probe[i]->acpi_madt_oem_check(oem_id, oem_table_id)) {
106 			if (!cmdline_apic) {
107 				genapic = apic_probe[i];
108 				printk(KERN_INFO "Switched to APIC driver `%s'.\n",
109 				       genapic->name);
110 			}
111 			return 1;
112 		}
113 	}
114 	return 0;
115 }
116