3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Suresh Siddha commit 73d63d038ee9f769f5e5b46792d227fe20e442c5 upstream. With the recent changes to clear_IO_APIC_pin() which tries to clear remoteIRR bit explicitly, some of the users started to see "Unable to reset IRR for apic .." messages. Close look shows that these are related to bogus IO-APIC entries which return's all 1's for their io-apic registers. And the above mentioned error messages are benign. But kernel should have ignored such io-apic's in the first place. Check if register 0, 1, 2 of the listed io-apic are all 1's and ignore such io-apic. Reported-by: Álvaro Castillo Tested-by: Jon Dufresne Signed-off-by: Suresh Siddha Cc: yinghai@kernel.org Cc: kernel-team@fedoraproject.org Cc: Josh Boyer Link: http://lkml.kernel.org/r/1331577393.31585.94.camel@sbsiddha-desk.sc.intel.com [ Performed minor cleanup of affected code. ] Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/apic/io_apic.c | 40 ++++++++++++++++++++++++++++++++-------- 1 file changed, 32 insertions(+), 8 deletions(-) --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -3963,18 +3963,36 @@ int mp_find_ioapic_pin(int ioapic, u32 g static __init int bad_ioapic(unsigned long address) { if (nr_ioapics >= MAX_IO_APICS) { - printk(KERN_WARNING "WARNING: Max # of I/O APICs (%d) exceeded " - "(found %d), skipping\n", MAX_IO_APICS, nr_ioapics); + pr_warn("WARNING: Max # of I/O APICs (%d) exceeded (found %d), skipping\n", + MAX_IO_APICS, nr_ioapics); return 1; } if (!address) { - printk(KERN_WARNING "WARNING: Bogus (zero) I/O APIC address" - " found in table, skipping!\n"); + pr_warn("WARNING: Bogus (zero) I/O APIC address found in table, skipping!\n"); return 1; } return 0; } +static __init int bad_ioapic_register(int idx) +{ + union IO_APIC_reg_00 reg_00; + union IO_APIC_reg_01 reg_01; + union IO_APIC_reg_02 reg_02; + + reg_00.raw = io_apic_read(idx, 0); + reg_01.raw = io_apic_read(idx, 1); + reg_02.raw = io_apic_read(idx, 2); + + if (reg_00.raw == -1 && reg_01.raw == -1 && reg_02.raw == -1) { + pr_warn("I/O APIC 0x%x registers return all ones, skipping!\n", + mpc_ioapic_addr(idx)); + return 1; + } + + return 0; +} + void __init mp_register_ioapic(int id, u32 address, u32 gsi_base) { int idx = 0; @@ -3991,6 +4009,12 @@ void __init mp_register_ioapic(int id, u ioapics[idx].mp_config.apicaddr = address; set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address); + + if (bad_ioapic_register(idx)) { + clear_fixmap(FIX_IO_APIC_BASE_0 + idx); + return; + } + ioapics[idx].mp_config.apicid = io_apic_unique_id(id); ioapics[idx].mp_config.apicver = io_apic_get_version(idx); @@ -4011,10 +4035,10 @@ void __init mp_register_ioapic(int id, u if (gsi_cfg->gsi_end >= gsi_top) gsi_top = gsi_cfg->gsi_end + 1; - printk(KERN_INFO "IOAPIC[%d]: apic_id %d, version %d, address 0x%x, " - "GSI %d-%d\n", idx, mpc_ioapic_id(idx), - mpc_ioapic_ver(idx), mpc_ioapic_addr(idx), - gsi_cfg->gsi_base, gsi_cfg->gsi_end); + pr_info("IOAPIC[%d]: apic_id %d, version %d, address 0x%x, GSI %d-%d\n", + idx, mpc_ioapic_id(idx), + mpc_ioapic_ver(idx), mpc_ioapic_addr(idx), + gsi_cfg->gsi_base, gsi_cfg->gsi_end); nr_ioapics++; }