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 <xen/param.h>
12 #include <asm/cache.h>
13 #include <asm/fixmap.h>
14 #include <asm/mpspec.h>
15 #include <asm/apicdef.h>
16 #include <asm/mach-generic/mach_apic.h>
17 #include <asm/setup.h>
18 
19 struct genapic __read_mostly genapic;
20 
21 const struct genapic *const __initconstrel apic_probe[] = {
22 	&apic_bigsmp,
23 	&apic_default,	/* must be last */
24 	NULL,
25 };
26 
27 static bool_t __initdata cmdline_apic;
28 
generic_bigsmp_probe(void)29 void __init generic_bigsmp_probe(void)
30 {
31 	/*
32 	 * This routine is used to switch to bigsmp mode when
33 	 * - There is no apic= option specified by the user
34 	 * - generic_apic_probe() has choosen apic_default as the sub_arch
35 	 * - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support
36 	 */
37 
38 	if (!cmdline_apic && genapic.name == apic_default.name)
39 		if (apic_bigsmp.probe()) {
40 			genapic = apic_bigsmp;
41 			printk(KERN_INFO "Overriding APIC driver with %s\n",
42 			       genapic.name);
43 		}
44 }
45 
genapic_apic_force(const char * str)46 static int __init genapic_apic_force(const char *str)
47 {
48 	int i, rc = -EINVAL;
49 
50 	for (i = 0; apic_probe[i]; i++)
51 		if (!strcmp(apic_probe[i]->name, str)) {
52 			genapic = *apic_probe[i];
53 			rc = 0;
54 		}
55 
56 	return rc;
57 }
58 custom_param("apic", genapic_apic_force);
59 
generic_apic_probe(void)60 void __init generic_apic_probe(void)
61 {
62 	bool changed;
63 	int i;
64 
65 	record_boot_APIC_mode();
66 
67 	check_x2apic_preenabled();
68 	cmdline_apic = changed = !!genapic.name;
69 
70 	for (i = 0; !changed && apic_probe[i]; i++) {
71 		if (apic_probe[i]->probe()) {
72 			changed = 1;
73 			genapic = *apic_probe[i];
74 		}
75 	}
76 	if (!changed)
77 		genapic = apic_default;
78 
79 	printk(KERN_INFO "Using APIC driver %s\n", genapic.name);
80 }
81 
82 /* These functions can switch the APIC even after the initial ->probe() */
83 
mps_oem_check(struct mp_config_table * mpc,char * oem,char * productid)84 int __init mps_oem_check(struct mp_config_table *mpc, char *oem, char *productid)
85 {
86 	int i;
87 	for (i = 0; apic_probe[i]; ++i) {
88 		if (apic_probe[i]->mps_oem_check(mpc,oem,productid)) {
89 			if (!cmdline_apic &&
90 			     genapic.name != apic_probe[i]->name) {
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.name != apic_probe[i]->name) {
108 				genapic = *apic_probe[i];
109 				printk(KERN_INFO "Switched to APIC driver `%s'.\n",
110 				       genapic.name);
111 			}
112 			return 1;
113 		}
114 	}
115 	return 0;
116 }
117