x86: add x2apic config
Impact: cleanup
so could deselect x2apic
and INTR_REMAP will select x2apic
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 1042d69..bce241f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -235,6 +235,20 @@
If you don't know what to do here, say N.
+config X86_X2APIC
+ bool "Support x2apic"
+ depends on X86_LOCAL_APIC && X86_64
+ ---help---
+ This enables x2apic support on CPUs that have this feature.
+
+ This allows 32-bit apic IDs (so it can support very large systems),
+ and accesses the local apic via MSRs not via mmio.
+
+ ( On certain CPU models you may need to enable INTR_REMAP too,
+ to get functional x2apic mode. )
+
+ If you don't know what to do here, say N.
+
config SPARSE_IRQ
bool "Support sparse irq numbering"
depends on PCI_MSI || HT_IRQ
@@ -1828,6 +1842,7 @@
config INTR_REMAP
bool "Support for Interrupt Remapping (EXPERIMENTAL)"
depends on X86_64 && X86_IO_APIC && PCI_MSI && ACPI && EXPERIMENTAL
+ select X86_X2APIC
---help---
Supports Interrupt remapping for IO-APIC and MSI devices.
To use x2apic mode in the CPU's which support x2APIC enhancements or
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index fba49f6..dc1db99 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -112,7 +112,7 @@
return low;
}
-#ifndef CONFIG_X86_32
+#ifdef CONFIG_X86_X2APIC
extern int x2apic;
extern void check_x2apic(void);
extern void enable_x2apic(void);
@@ -131,7 +131,19 @@
return 0;
}
#else
-#define x2apic_enabled() 0
+static inline void check_x2apic(void)
+{
+}
+static inline void enable_x2apic(void)
+{
+}
+static inline void enable_IR_x2apic(void)
+{
+}
+static inline int x2apic_enabled(void)
+{
+ return 0;
+}
#endif
struct apic_ops {
@@ -177,7 +189,7 @@
extern int get_physical_broadcast(void);
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_X86_X2APIC
static inline void ack_x2APIC_irq(void)
{
/* Docs say use 0 for future compatibility */
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 24f357e..1cefd21 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -117,8 +117,8 @@
# 64 bit specific files
ifeq ($(CONFIG_X86_64),y)
obj-y += genapic_64.o genapic_flat_64.o
- obj-y += genx2apic_cluster.o
- obj-y += genx2apic_phys.o
+ obj-$(CONFIG_X86_X2APIC) += genx2apic_cluster.o
+ obj-$(CONFIG_X86_X2APIC) += genx2apic_phys.o
obj-$(CONFIG_X86_UV) += genx2apic_uv_x.o tlb_uv.o
obj-$(CONFIG_X86_UV) += bios_uv.o uv_irq.o uv_sysfs.o
obj-$(CONFIG_X86_PM_TIMER) += pmtimer_64.o
diff --git a/arch/x86/kernel/apic.c b/arch/x86/kernel/apic.c
index a894eea..004aa1c 100644
--- a/arch/x86/kernel/apic.c
+++ b/arch/x86/kernel/apic.c
@@ -112,11 +112,7 @@
__setup("apicpmtimer", setup_apicpmtimer);
#endif
-#ifdef CONFIG_X86_64
-#define HAVE_X2APIC
-#endif
-
-#ifdef HAVE_X2APIC
+#ifdef CONFIG_X86_X2APIC
int x2apic;
/* x2apic enabled before OS handover */
static int x2apic_preenabled;
@@ -269,7 +265,7 @@
struct apic_ops __read_mostly *apic_ops = &xapic_ops;
EXPORT_SYMBOL_GPL(apic_ops);
-#ifdef HAVE_X2APIC
+#ifdef CONFIG_X86_X2APIC
static void x2apic_wait_icr_idle(void)
{
/* no need to wait for icr idle in x2apic */
@@ -1320,11 +1316,14 @@
apic_pm_activate();
}
-#ifdef HAVE_X2APIC
+#ifdef CONFIG_X86_X2APIC
void check_x2apic(void)
{
int msr, msr2;
+ if (!cpu_has_x2apic)
+ return;
+
rdmsr(MSR_IA32_APICBASE, msr, msr2);
if (msr & X2APIC_ENABLE) {
@@ -1338,6 +1337,9 @@
{
int msr, msr2;
+ if (!x2apic)
+ return;
+
rdmsr(MSR_IA32_APICBASE, msr, msr2);
if (!(msr & X2APIC_ENABLE)) {
pr_info("Enabling x2apic\n");
@@ -1439,7 +1441,7 @@
return;
}
-#endif /* HAVE_X2APIC */
+#endif /* CONFIG_X86_X2APIC */
#ifdef CONFIG_X86_64
/*
@@ -1570,7 +1572,7 @@
*/
void __init init_apic_mappings(void)
{
-#ifdef HAVE_X2APIC
+#ifdef CONFIG_X86_X2APIC
if (x2apic) {
boot_cpu_physical_apicid = read_apic_id();
return;
@@ -1634,9 +1636,7 @@
}
#endif
-#ifdef HAVE_X2APIC
enable_IR_x2apic();
-#endif
#ifdef CONFIG_X86_64
default_setup_apic_routing();
#endif
@@ -2021,7 +2021,7 @@
local_irq_save(flags);
-#ifdef HAVE_X2APIC
+#ifdef CONFIG_X86_X2APIC
if (x2apic)
enable_x2apic();
else
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 4db150e..4b5d13e 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1051,7 +1051,7 @@
barrier();
check_efer();
- if (cpu != 0 && x2apic)
+ if (cpu != 0)
enable_x2apic();
/*
diff --git a/arch/x86/kernel/genapic_64.c b/arch/x86/kernel/genapic_64.c
index 820dea5d..cdc4772 100644
--- a/arch/x86/kernel/genapic_64.c
+++ b/arch/x86/kernel/genapic_64.c
@@ -35,8 +35,10 @@
#ifdef CONFIG_X86_UV
&apic_x2apic_uv_x,
#endif
+#ifdef CONFIG_X86_X2APIC
&apic_x2apic_phys,
&apic_x2apic_cluster,
+#endif
&apic_physflat,
NULL,
};
@@ -46,10 +48,12 @@
*/
void __init default_setup_apic_routing(void)
{
+#ifdef CONFIG_X86_X2APIC
if (apic == &apic_x2apic_phys || apic == &apic_x2apic_cluster) {
if (!intr_remapping_enabled)
apic = &apic_flat;
}
+#endif
if (apic == &apic_flat) {
if (max_physical_apicid >= 8)
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 8fce6c7..43d9644 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -836,8 +836,7 @@
#else
num_physpages = max_pfn;
- if (cpu_has_x2apic)
- check_x2apic();
+ check_x2apic();
/* How many end-of-memory variables you have, grandma! */
/* need this before calling reserve_initrd */
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 1083495..b5f2b69 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1128,8 +1128,8 @@
current_thread_info()->cpu = 0; /* needed? */
set_cpu_sibling_map(0);
-#ifdef CONFIG_X86_64
enable_IR_x2apic();
+#ifdef CONFIG_X86_64
default_setup_apic_routing();
#endif