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Diffstat (limited to 'arch/x86/kernel/apic/apic.c')
-rw-r--r--arch/x86/kernel/apic/apic.c88
1 files changed, 69 insertions, 19 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 8cf86fb3b4e3..850657d1b0ed 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -52,6 +52,7 @@
#include <asm/mce.h>
#include <asm/kvm_para.h>
#include <asm/tsc.h>
+#include <asm/atomic.h>
unsigned int num_processors;
@@ -370,38 +371,87 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
}
/*
- * Setup extended LVT, AMD specific (K8, family 10h)
+ * Setup extended LVT, AMD specific
*
- * Vector mappings are hard coded. On K8 only offset 0 (APIC500) and
- * MCE interrupts are supported. Thus MCE offset must be set to 0.
+ * Software should use the LVT offsets the BIOS provides. The offsets
+ * are determined by the subsystems using it like those for MCE
+ * threshold or IBS. On K8 only offset 0 (APIC500) and MCE interrupts
+ * are supported. Beginning with family 10h at least 4 offsets are
+ * available.
*
- * If mask=1, the LVT entry does not generate interrupts while mask=0
- * enables the vector. See also the BKDGs.
+ * Since the offsets must be consistent for all cores, we keep track
+ * of the LVT offsets in software and reserve the offset for the same
+ * vector also to be used on other cores. An offset is freed by
+ * setting the entry to APIC_EILVT_MASKED.
+ *
+ * If the BIOS is right, there should be no conflicts. Otherwise a
+ * "[Firmware Bug]: ..." error message is generated. However, if
+ * software does not properly determines the offsets, it is not
+ * necessarily a BIOS bug.
*/
-#define APIC_EILVT_LVTOFF_MCE 0
-#define APIC_EILVT_LVTOFF_IBS 1
+static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
-static void setup_APIC_eilvt(u8 lvt_off, u8 vector, u8 msg_type, u8 mask)
+static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
{
- unsigned long reg = (lvt_off << 4) + APIC_EILVTn(0);
- unsigned int v = (mask << 16) | (msg_type << 8) | vector;
-
- apic_write(reg, v);
+ return (old & APIC_EILVT_MASKED)
+ || (new == APIC_EILVT_MASKED)
+ || ((new & ~APIC_EILVT_MASKED) == old);
}
-u8 setup_APIC_eilvt_mce(u8 vector, u8 msg_type, u8 mask)
+static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
{
- setup_APIC_eilvt(APIC_EILVT_LVTOFF_MCE, vector, msg_type, mask);
- return APIC_EILVT_LVTOFF_MCE;
+ unsigned int rsvd; /* 0: uninitialized */
+
+ if (offset >= APIC_EILVT_NR_MAX)
+ return ~0;
+
+ rsvd = atomic_read(&eilvt_offsets[offset]) & ~APIC_EILVT_MASKED;
+ do {
+ if (rsvd &&
+ !eilvt_entry_is_changeable(rsvd, new))
+ /* may not change if vectors are different */
+ return rsvd;
+ rsvd = atomic_cmpxchg(&eilvt_offsets[offset], rsvd, new);
+ } while (rsvd != new);
+
+ return new;
}
-u8 setup_APIC_eilvt_ibs(u8 vector, u8 msg_type, u8 mask)
+/*
+ * If mask=1, the LVT entry does not generate interrupts while mask=0
+ * enables the vector. See also the BKDGs.
+ */
+
+int setup_APIC_eilvt(u8 offset, u8 vector, u8 msg_type, u8 mask)
{
- setup_APIC_eilvt(APIC_EILVT_LVTOFF_IBS, vector, msg_type, mask);
- return APIC_EILVT_LVTOFF_IBS;
+ unsigned long reg = APIC_EILVTn(offset);
+ unsigned int new, old, reserved;
+
+ new = (mask << 16) | (msg_type << 8) | vector;
+ old = apic_read(reg);
+ reserved = reserve_eilvt_offset(offset, new);
+
+ if (reserved != new) {
+ pr_err(FW_BUG "cpu %d, try to setup vector 0x%x, but "
+ "vector 0x%x was already reserved by another core, "
+ "APIC%lX=0x%x\n",
+ smp_processor_id(), new, reserved, reg, old);
+ return -EINVAL;
+ }
+
+ if (!eilvt_entry_is_changeable(old, new)) {
+ pr_err(FW_BUG "cpu %d, try to setup vector 0x%x but "
+ "register already in use, APIC%lX=0x%x\n",
+ smp_processor_id(), new, reg, old);
+ return -EBUSY;
+ }
+
+ apic_write(reg, new);
+
+ return 0;
}
-EXPORT_SYMBOL_GPL(setup_APIC_eilvt_ibs);
+EXPORT_SYMBOL_GPL(setup_APIC_eilvt);
/*
* Program the next event, relative to now