@@ -3660,19 +3660,22 @@ static int io_apic_get_unique_id(int ioapic, int apic_id)
return apic_id;
}
-static u8 io_apic_unique_id(u8 id)
+static u8 io_apic_unique_id(int idx, u8 id)
{
if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
!APIC_XAPIC(apic_version[boot_cpu_physical_apicid]))
- return io_apic_get_unique_id(nr_ioapics, id);
+ return io_apic_get_unique_id(idx, id);
else
return id;
}
#else
-static u8 io_apic_unique_id(u8 id)
+static u8 io_apic_unique_id(int idx, u8 id)
{
int i;
+ u8 new_id;
+ unsigned long flags;
DECLARE_BITMAP(used, 256);
+ union IO_APIC_reg_00 reg_00;
bitmap_zero(used, 256);
for_each_ioapic(i)
@@ -3680,7 +3683,32 @@ static u8 io_apic_unique_id(u8 id)
if (!test_bit(id, used))
return id;
- return find_first_zero_bit(used, 256);
+
+ /* check register at first */
+ raw_spin_lock_irqsave(&ioapic_lock, flags);
+ reg_00.raw = io_apic_read(idx, 0);
+ raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+ new_id = reg_00.bits.ID;
+ if (!test_bit(new_id, used)) {
+ apic_printk(APIC_VERBOSE, KERN_INFO
+ "IOAPIC[%d]: Using reg apic_id %d instead of %d\n",
+ idx, new_id, id);
+ return new_id;
+ }
+
+ new_id = find_first_zero_bit(used, 256);
+ reg_00.bits.ID = new_id;
+ raw_spin_lock_irqsave(&ioapic_lock, flags);
+ io_apic_write(idx, 0, reg_00.raw);
+ reg_00.raw = io_apic_read(idx, 0);
+ raw_spin_unlock_irqrestore(&ioapic_lock, flags);
+
+ /* Sanity check */
+ if (reg_00.bits.ID != new_id)
+ pr_warn("IOAPIC[%d]: Unable to change apic_id to %d!\n",
+ idx, new_id);
+
+ return new_id;
}
#endif
@@ -3955,7 +3983,7 @@ int __mp_register_ioapic(int id, u32 address, u32 gsi_base, bool hotadd)
if (bad_ioapic_register(idx))
goto clear_out;
- ioapics[idx].mp_config.apicid = io_apic_unique_id(id);
+ ioapics[idx].mp_config.apicid = io_apic_unique_id(idx, id);
ioapics[idx].mp_config.apicver = io_apic_get_version(idx);
/*
Checking the id in register, if that is duplicated, will pick one and update id register. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> --- arch/x86/kernel/apic/io_apic.c | 38 +++++++++++++++++++++++++++++++++----- 1 file changed, 33 insertions(+), 5 deletions(-)