linux-kernel - [PATCH] Use x2apic_supported() in the default_apic_id

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Date:	Thu, 15 Mar 2012 19:03:03 +0100
From:	Steffen Persvold <sp@...ascale.com>
To:	Ingo Molnar <mingo@...hat.com>,
	Thomas Gleixner <tglx@...utronix.de>
Cc:	"H. Peter Anvin" <hpa@...or.com>,
	Daniel J Blueman <daniel@...ascale-asia.com>,
	Yinghai Lu <yinghai@...nel.org>,
	Suresh Siddha <suresh.b.siddha@...el.com>,
	linux-kernel@...r.kernel.org, x86@...nel.org,
	Steffen Persvold <sp@...ascale.com>
Subject: [PATCH] Use x2apic_supported() in the default_apic_id_valid() function.

Use x2apic_supported() in the default_apic_id_valid() function. If x2apic mode is disabled (via nox2apic for example), x2apic_supported() will return false.

This allows us to substitute the check in arch/x86/kernel/acpi/boot.c::acpi_parse_x2apic and avoid feigning the x2apic cpu feature in the NumaChip apic code.

Signed-off-by: Steffen Persvold <sp@...ascale.com>
Reviewed-by: Daniel J Blueman <daniel@...ascale-asia.com>

---
 arch/x86/include/asm/apic.h          |    2 +-
 arch/x86/kernel/acpi/boot.c          |    2 +-
 arch/x86/kernel/apic/apic_numachip.c |    1 -
 arch/x86/mm/srat.c                   |    7 +------
 4 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index a9371c9..b6d3987 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -535,7 +535,7 @@ static inline unsigned int read_apic_id(void)
 
 static inline int default_apic_id_valid(int apicid)
 {
-	return x2apic_mode || (apicid < 255);
+	return x2apic_supported() || (apicid < 255);
 }
 
 extern void default_setup_apic_routing(void);
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 406ed77..0f42c2f 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -239,7 +239,7 @@ acpi_parse_x2apic(struct acpi_subtable_header *header, const unsigned long end)
 	 * to not preallocating memory for all NR_CPUS
 	 * when we use CPU hotplug.
 	 */
-	if (!cpu_has_x2apic && (apic_id >= 0xff) && enabled)
+	if (!apic->apic_id_valid(apic_id) && enabled)
 		printk(KERN_WARNING PREFIX "x2apic entry ignored\n");
 	else
 		acpi_register_lapic(apic_id, enabled);
diff --git a/arch/x86/kernel/apic/apic_numachip.c b/arch/x86/kernel/apic/apic_numachip.c
index d9ea5f3..c13fa9f 100644
--- a/arch/x86/kernel/apic/apic_numachip.c
+++ b/arch/x86/kernel/apic/apic_numachip.c
@@ -233,7 +233,6 @@ static int __cpuinit numachip_acpi_madt_oem_check(char *oem_id, char *oem_table_
 {
 	if (!strncmp(oem_id, "NUMASC", 6)) {
 		numachip_system = 1;
-		setup_force_cpu_cap(X86_FEATURE_X2APIC);
 		return 1;
 	}
 
diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c
index 1c1c4f4..7efd0c6 100644
--- a/arch/x86/mm/srat.c
+++ b/arch/x86/mm/srat.c
@@ -69,12 +69,6 @@ acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa)
 	if ((pa->flags & ACPI_SRAT_CPU_ENABLED) == 0)
 		return;
 	pxm = pa->proximity_domain;
-	apic_id = pa->apic_id;
-	if (!cpu_has_x2apic && (apic_id >= 0xff)) {
-		printk(KERN_INFO "SRAT: PXM %u -> X2APIC 0x%04x ignored\n",
-			 pxm, apic_id);
-		return;
-	}
 	node = setup_node(pxm);
 	if (node < 0) {
 		printk(KERN_ERR "SRAT: Too many proximity domains %x\n", pxm);
@@ -82,6 +76,7 @@ acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa)
 		return;
 	}
 
+	apic_id = pa->apic_id;
 	if (apic_id >= MAX_LOCAL_APIC) {
 		printk(KERN_INFO "SRAT: PXM %u -> APIC 0x%04x -> Node %u skipped apicid that is too big\n", pxm, apic_id, node);
 		return;
-- 
1.7.4.1

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