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authorYinghai Lu <yhlu.kernel@gmail.com>2008-09-03 16:58:31 -0700
committerIngo Molnar <mingo@elte.hu>2008-10-16 16:53:04 +0200
commita11b5abef50722e42a7d13f6b799c4f606fcb797 (patch)
treeeed224f07b6c8fc20cc4a454578e34721999b763
parentc59d85a7b7822b83fc9783314543eea0ca860480 (diff)
x2apic: fix reserved APIC register accesses in print_local_APIC()
APIC_ARBPRI is a reserved register for XAPIC and beyond. APIC_RRR is a reserved register except for 82489DX, APIC for Pentium processors. APIC_EOI is a write only register. APIC_DFR is reserved in x2apic mode. Access to these registers in x2apic will result in #GP fault. Fix these apic register accesses. Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Cc: Maciej W. Rozycki <macro@linux-mips.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/io_apic.c27
-rw-r--r--include/asm-x86/apic.h14
2 files changed, 32 insertions, 9 deletions
diff --git a/arch/x86/kernel/io_apic.c b/arch/x86/kernel/io_apic.c
index d28128e0392..93ceb19d1e9 100644
--- a/arch/x86/kernel/io_apic.c
+++ b/arch/x86/kernel/io_apic.c
@@ -1751,21 +1751,30 @@ __apicdebuginit(void) print_local_APIC(void *dummy)
printk(KERN_DEBUG "... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK);
if (APIC_INTEGRATED(ver)) { /* !82489DX */
- v = apic_read(APIC_ARBPRI);
- printk(KERN_DEBUG "... APIC ARBPRI: %08x (%02x)\n", v,
- v & APIC_ARBPRI_MASK);
+ if (!APIC_XAPIC(ver)) {
+ v = apic_read(APIC_ARBPRI);
+ printk(KERN_DEBUG "... APIC ARBPRI: %08x (%02x)\n", v,
+ v & APIC_ARBPRI_MASK);
+ }
v = apic_read(APIC_PROCPRI);
printk(KERN_DEBUG "... APIC PROCPRI: %08x\n", v);
}
- v = apic_read(APIC_EOI);
- printk(KERN_DEBUG "... APIC EOI: %08x\n", v);
- v = apic_read(APIC_RRR);
- printk(KERN_DEBUG "... APIC RRR: %08x\n", v);
+ /*
+ * Remote read supported only in the 82489DX and local APIC for
+ * Pentium processors.
+ */
+ if (!APIC_INTEGRATED(ver) || maxlvt == 3) {
+ v = apic_read(APIC_RRR);
+ printk(KERN_DEBUG "... APIC RRR: %08x\n", v);
+ }
+
v = apic_read(APIC_LDR);
printk(KERN_DEBUG "... APIC LDR: %08x\n", v);
- v = apic_read(APIC_DFR);
- printk(KERN_DEBUG "... APIC DFR: %08x\n", v);
+ if (!x2apic_enabled()) {
+ v = apic_read(APIC_DFR);
+ printk(KERN_DEBUG "... APIC DFR: %08x\n", v);
+ }
v = apic_read(APIC_SPIV);
printk(KERN_DEBUG "... APIC SPIV: %08x\n", v);
diff --git a/include/asm-x86/apic.h b/include/asm-x86/apic.h
index 2d970f6bc2a..ef1d72dbdfe 100644
--- a/include/asm-x86/apic.h
+++ b/include/asm-x86/apic.h
@@ -98,6 +98,20 @@ extern void check_x2apic(void);
extern void enable_x2apic(void);
extern void enable_IR_x2apic(void);
extern void x2apic_icr_write(u32 low, u32 id);
+static inline int x2apic_enabled(void)
+{
+ int msr, msr2;
+
+ if (!cpu_has_x2apic)
+ return 0;
+
+ rdmsr(MSR_IA32_APICBASE, msr, msr2);
+ if (msr & X2APIC_ENABLE)
+ return 1;
+ return 0;
+}
+#else
+#define x2apic_enabled() 0
#endif
struct apic_ops {