From patchwork Fri Feb 8 19:28:20 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [v2,23/26] x86, ioapic: Find usable ioapic id for 64bit. Date: Fri, 08 Feb 2013 09:28:20 -0000 From: Yinghai Lu X-Patchwork-Id: 219269 Message-Id: <1360351703-20571-24-git-send-email-yinghai@kernel.org> To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Bjorn Helgaas , "Rafael J. Wysocki" Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Yinghai Lu , Joerg Roedel , Konrad Rzeszutek Wilk , Sebastian Andrzej Siewior Checking the id in register, if that is duplicated, will pick one and update that to register. Signed-off-by: Yinghai Lu Cc: Joerg Roedel Cc: Konrad Rzeszutek Wilk Cc: Sebastian Andrzej Siewior --- arch/x86/kernel/apic/io_apic.c | 41 +++++++++++++++++++++++++++++++++------- 1 file changed, 34 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index d4c68d9..42f273b 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -3663,27 +3663,54 @@ static int __init io_apic_get_unique_id(int ioapic, int apic_id) return apic_id; } -static u8 __init io_apic_unique_id(u8 id) +static u8 __init 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 __init 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 (i = 0; i < nr_ioapics; i++) { + for (i = 0; i < nr_ioapics; i++) __set_bit(mpc_ioapic_id(i), used); - } 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 @@ -3964,7 +3991,7 @@ int __mp_register_ioapic(int id, u32 address, u32 gsi_base, bool hotadd) if (bad_ioapic_register(idx)) goto failed; - 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); /*