[PATCH] i386: Support physical cpu hotplug for x86_64

This patch enables ACPI based physical CPU hotplug support for x86_64. Implements acpi_map_lsapic() and acpi_unmap_lsapic() to support physical cpu hotplug. Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@muc.de> Cc: "Brown, Len" <len.brown@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org>

[PATCH] i386: Support physical cpu hotplug for x86_64
This patch enables ACPI based physical CPU hotplug support for x86_64. Implements acpi_map_lsapic() and acpi_unmap_lsapic() to support physical cpu hotplug. Signed-off-by: Ashok Raj <ashok.raj@intel.com> Signed-off-by: Andi Kleen <ak@suse.de> Cc: Andi Kleen <ak@muc.de> Cc: "Brown, Len" <len.brown@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org>
Ashok Raj · Andi Kleen
1 parent 40bee2ee73
Showing 3 changed files with 67 additions and 5 deletions Side-by-side Diff
arch/i386/kernel/acpi/boot.c
arch/i386/kernel/mpparse.c
include/asm-i386/smp.h
@@ -26,6 +26,7 @@
 #include <linux/init.h>
 #include <linux/acpi.h>
 #include <linux/efi.h>
+#include <linux/cpumask.h>
 #include <linux/module.h>
 #include <linux/dmi.h>
 #include <linux/irq.h>
  
@@ -512,16 +513,76 @@
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 int acpi_map_lsapic(acpi_handle handle, int *pcpu)
 {
-	/* TBD */
-	return -EINVAL;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object *obj;
+	struct acpi_table_lapic *lapic;
+	cpumask_t tmp_map, new_map;
+	u8 physid;
+	int cpu;
+
+	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
+		return -EINVAL;
+
+	if (!buffer.length || !buffer.pointer)
+		return -EINVAL;
+
+	obj = buffer.pointer;
+	if (obj->type != ACPI_TYPE_BUFFER ||
+	    obj->buffer.length < sizeof(*lapic)) {
+		kfree(buffer.pointer);
+		return -EINVAL;
+	}
+
+	lapic = (struct acpi_table_lapic *)obj->buffer.pointer;
+
+	if ((lapic->header.type != ACPI_MADT_LAPIC) ||
+	    (!lapic->flags.enabled)) {
+		kfree(buffer.pointer);
+		return -EINVAL;
+	}
+
+	physid = lapic->id;
+
+	kfree(buffer.pointer);
+	buffer.length = ACPI_ALLOCATE_BUFFER;
+	buffer.pointer = NULL;
+
+	tmp_map = cpu_present_map;
+	mp_register_lapic(physid, lapic->flags.enabled);
+
+	/*
+	 * If mp_register_lapic successfully generates a new logical cpu
+	 * number, then the following will get us exactly what was mapped
+	 */
+	cpus_andnot(new_map, cpu_present_map, tmp_map);
+	if (cpus_empty(new_map)) {
+		printk ("Unable to map lapic to logical cpu number\n");
+		return -EINVAL;
+	}
+
+	cpu = first_cpu(new_map);
+
+	*pcpu = cpu;
+	return 0;
 }
  
 EXPORT_SYMBOL(acpi_map_lsapic);
  
 int acpi_unmap_lsapic(int cpu)
 {
-	/* TBD */
-	return -EINVAL;
+	int i;
+
+	for_each_possible_cpu(i) {
+		if (x86_acpiid_to_apicid[i] == x86_cpu_to_apicid[cpu]) {
+			x86_acpiid_to_apicid[i] = -1;
+			break;
+		}
+	}
+	x86_cpu_to_apicid[cpu] = -1;
+	cpu_clear(cpu, cpu_present_map);
+	num_processors--;
+
+	return (0);
 }
  
 EXPORT_SYMBOL(acpi_unmap_lsapic);
@@ -69,7 +69,7 @@
 /* Processor that is doing the boot up */
 unsigned int boot_cpu_physical_apicid = -1U;
 /* Internal processor count */
-static unsigned int __devinitdata num_processors;
+unsigned int __cpuinitdata num_processors;
  
 /* Bitmask of physically existing CPUs */
 physid_mask_t phys_cpu_present_map;
@@ -84,6 +84,7 @@
  
 extern int __cpu_disable(void);
 extern void __cpu_die(unsigned int cpu);
+extern unsigned int num_processors;
  
 #endif /* !__ASSEMBLY__ */
...	...	@@ -26,6 +26,7 @@
26	26	#include <linux/init.h>
27	27	#include <linux/acpi.h>
28	28	#include <linux/efi.h>
	29	+#include <linux/cpumask.h>
29	30	#include <linux/module.h>
30	31	#include <linux/dmi.h>
31	32	#include <linux/irq.h>
32	33
...	...	@@ -512,16 +513,76 @@
512	513	#ifdef CONFIG_ACPI_HOTPLUG_CPU
513	514	int acpi_map_lsapic(acpi_handle handle, int *pcpu)
514	515	{
515		- /* TBD */
516		- return -EINVAL;
	516	+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
	517	+ union acpi_object *obj;
	518	+ struct acpi_table_lapic *lapic;
	519	+ cpumask_t tmp_map, new_map;
	520	+ u8 physid;
	521	+ int cpu;
	522	+
	523	+ if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
	524	+ return -EINVAL;
	525	+
	526	+ if (!buffer.length \|\| !buffer.pointer)
	527	+ return -EINVAL;
	528	+
	529	+ obj = buffer.pointer;
	530	+ if (obj->type != ACPI_TYPE_BUFFER \|\|
	531	+ obj->buffer.length < sizeof(*lapic)) {
	532	+ kfree(buffer.pointer);
	533	+ return -EINVAL;
	534	+ }
	535	+
	536	+ lapic = (struct acpi_table_lapic *)obj->buffer.pointer;
	537	+
	538	+ if ((lapic->header.type != ACPI_MADT_LAPIC) \|\|
	539	+ (!lapic->flags.enabled)) {
	540	+ kfree(buffer.pointer);
	541	+ return -EINVAL;
	542	+ }
	543	+
	544	+ physid = lapic->id;
	545	+
	546	+ kfree(buffer.pointer);
	547	+ buffer.length = ACPI_ALLOCATE_BUFFER;
	548	+ buffer.pointer = NULL;
	549	+
	550	+ tmp_map = cpu_present_map;
	551	+ mp_register_lapic(physid, lapic->flags.enabled);
	552	+
	553	+ /*
	554	+ * If mp_register_lapic successfully generates a new logical cpu
	555	+ * number, then the following will get us exactly what was mapped
	556	+ */
	557	+ cpus_andnot(new_map, cpu_present_map, tmp_map);
	558	+ if (cpus_empty(new_map)) {
	559	+ printk ("Unable to map lapic to logical cpu number\n");
	560	+ return -EINVAL;
	561	+ }
	562	+
	563	+ cpu = first_cpu(new_map);
	564	+
	565	+ *pcpu = cpu;
	566	+ return 0;
517	567	}
518	568
519	569	EXPORT_SYMBOL(acpi_map_lsapic);
520	570
521	571	int acpi_unmap_lsapic(int cpu)
522	572	{
523		- /* TBD */
524		- return -EINVAL;
	573	+ int i;
	574	+
	575	+ for_each_possible_cpu(i) {
	576	+ if (x86_acpiid_to_apicid[i] == x86_cpu_to_apicid[cpu]) {
	577	+ x86_acpiid_to_apicid[i] = -1;
	578	+ break;
	579	+ }
	580	+ }
	581	+ x86_cpu_to_apicid[cpu] = -1;
	582	+ cpu_clear(cpu, cpu_present_map);
	583	+ num_processors--;
	584	+
	585	+ return (0);
525	586	}
526	587
527	588	EXPORT_SYMBOL(acpi_unmap_lsapic);
...	...	@@ -69,7 +69,7 @@
69	69	/* Processor that is doing the boot up */
70	70	unsigned int boot_cpu_physical_apicid = -1U;
71	71	/* Internal processor count */
72		-static unsigned int __devinitdata num_processors;
	72	+unsigned int __cpuinitdata num_processors;
73	73
74	74	/* Bitmask of physically existing CPUs */
75	75	physid_mask_t phys_cpu_present_map;
...	...	@@ -84,6 +84,7 @@
84	84
85	85	extern int __cpu_disable(void);
86	86	extern void __cpu_die(unsigned int cpu);
	87	+extern unsigned int num_processors;
87	88
88	89	#endif /* !__ASSEMBLY__ */
89	90