From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yinghai Lu Subject: [PATCH v5 23/33] x86, ioapic: Find usable ioapic id for 64bit. Date: Thu, 2 Jan 2014 16:05:55 -0800 Message-ID: <1388707565-16535-24-git-send-email-yinghai@kernel.org> References: <1388707565-16535-1-git-send-email-yinghai@kernel.org> Return-path: In-Reply-To: <1388707565-16535-1-git-send-email-yinghai@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Tony Luck , Bjorn Helgaas , "Rafael J. Wysocki" Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, Yinghai Lu , Joerg Roedel , Konrad Rzeszutek Wilk , Sebastian Andrzej Siewior List-Id: linux-acpi@vger.kernel.org Checking the id in register, if that is duplicated, will pick one and update id register. Signed-off-by: Yinghai Lu Cc: Joerg Roedel Cc: Konrad Rzeszutek Wilk Cc: Sebastian Andrzej Siewior --- arch/x86/kernel/apic/io_apic.c | 38 +++++++++++++++++++++++++++++++++----- 1 file changed, 33 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index af6cbcd..248a21d 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -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); /* -- 1.8.4