[PATCH] x86: APIC: Remove apic_write_around(); use alternatives - Kernel

This is a discussion on [PATCH] x86: APIC: Remove apic_write_around(); use alternatives - Kernel ; Use alternatives to select the workaround for the 11AP Pentium erratum for the affected steppings on the fly rather than build time. Remove the X86_GOOD_APIC configuration option and replace all the calls to apic_write_around() with plain apic_write(), protecting accesses to ...

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Thread: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

  1. [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    Use alternatives to select the workaround for the 11AP Pentium erratum
    for the affected steppings on the fly rather than build time. Remove the
    X86_GOOD_APIC configuration option and replace all the calls to
    apic_write_around() with plain apic_write(), protecting accesses to the
    ESR as appropriate due to the 3AP Pentium erratum. Remove
    apic_read_around() and all its invocations altogether as not needed.
    Remove apic_write_atomic() and all its implementing backends. The use of
    ASM_OUTPUT2() is not strictly needed for input constraints, but I have
    used it for readability's sake.

    Signed-off-by: Maciej W. Rozycki
    ---
    Ingo,

    I had the feeling no one else was brave enough to do it, so I went ahead
    and here it is. Verified by checking the generated assembly and tested
    with both a 32-bit and a 64-bit configuration, also with the 11AP
    "feature" forced on and verified with gdb on /proc/kcore to work as
    expected (as an 11AP machines are quite hard to get hands on these days).
    Some script complained about the use of "volatile", but apic_write() needs
    it for the same reason and is effectively a replacement for writel(), so I
    have disregarded it.

    This patch applies on top of the patches sent recently, in particular
    patch-next-2.6.26-rc9-20080711-ioapic-print-timer-2 sent the other day and
    hopefully will apply cleanly to your tree. I understand you are now busy
    merging with Linus, but once you are done with that and get at this patch,
    then please do let me know if there are any conflicts and I will
    regenerate it against a refreshed tree.

    I am not sure what the policy wrt defconfig files is, they are generated
    and there is risk of a conflict resulting from an unrelated change, so I
    have left changes to them out. The option will get removed from them at
    the next run.

    Some testing with machines other than mine will be needed to avoid some
    stupid mistake, but despite its volume, the change is not really that
    intrusive, so I am fairly confident that because it works for me, it will
    everywhere.

    Maciej

    patch-next-2.6.26-rc9-20080711-apic-write-5
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/Kconfig.cpu linux-next-2.6.26-rc9-20080711/arch/x86/Kconfig.cpu
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/Kconfig.cpu 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/Kconfig.cpu 2008-07-16 13:59:09.000000000 +0000
    @@ -362,10 +362,6 @@ config X86_ALIGNMENT_16
    def_bool y
    depends on MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCYRIXIII || X86_ELAN || MK6 || M586MMX || M586TSC || M586 || M486 || MVIAC3_2 || MGEODEGX1

    -config X86_GOOD_APIC
    - def_bool y
    - depends on MK7 || MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || MK8 || MEFFICEON || MCORE2 || MVIAC7 || X86_64
    -
    config X86_INTEL_USERCOPY
    def_bool y
    depends on MPENTIUM4 || MPENTIUMM || MPENTIUMIII || MPENTIUMII || M586MMX || X86_GENERIC || MK8 || MK7 || MEFFICEON || MCORE2
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/apic_32.c linux-next-2.6.26-rc9-20080711/arch/x86/kernel/apic_32.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/apic_32.c 2008-07-16 14:50:07.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/kernel/apic_32.c 2008-07-16 14:43:23.000000000 +0000
    @@ -177,7 +177,7 @@ void __cpuinit enable_NMI_through_LVT0(v
    /* Level triggered for 82489DX */
    if (!lapic_is_integrated())
    v |= APIC_LVT_LEVEL_TRIGGER;
    - apic_write_around(APIC_LVT0, v);
    + apic_write(APIC_LVT0, v);
    }

    /**
    @@ -212,9 +212,6 @@ int lapic_get_maxlvt(void)
    * this function twice on the boot CPU, once with a bogus timeout
    * value, second time for real. The other (noncalibrating) CPUs
    * call this function only once, with the real, calibrated value.
    - *
    - * We do reads before writes even if unnecessary, to get around the
    - * P5 APIC double write bug.
    */
    static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
    {
    @@ -229,18 +226,18 @@ static void __setup_APIC_LVTT(unsigned i
    if (!irqen)
    lvtt_value |= APIC_LVT_MASKED;

    - apic_write_around(APIC_LVTT, lvtt_value);
    + apic_write(APIC_LVTT, lvtt_value);

    /*
    * Divide PICLK by 16
    */
    tmp_value = apic_read(APIC_TDCR);
    - apic_write_around(APIC_TDCR, (tmp_value
    - & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
    - | APIC_TDR_DIV_16);
    + apic_write(APIC_TDCR,
    + (tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
    + APIC_TDR_DIV_16);

    if (!oneshot)
    - apic_write_around(APIC_TMICT, clocks/APIC_DIVISOR);
    + apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
    }

    /*
    @@ -249,7 +246,7 @@ static void __setup_APIC_LVTT(unsigned i
    static int lapic_next_event(unsigned long delta,
    struct clock_event_device *evt)
    {
    - apic_write_around(APIC_TMICT, delta);
    + apic_write(APIC_TMICT, delta);
    return 0;
    }

    @@ -278,7 +275,7 @@ static void lapic_timer_setup(enum clock
    case CLOCK_EVT_MODE_SHUTDOWN:
    v = apic_read(APIC_LVTT);
    v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
    - apic_write_around(APIC_LVTT, v);
    + apic_write(APIC_LVTT, v);
    break;
    case CLOCK_EVT_MODE_RESUME:
    /* Nothing to do here */
    @@ -693,44 +690,44 @@ void clear_local_APIC(void)
    */
    if (maxlvt >= 3) {
    v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
    - apic_write_around(APIC_LVTERR, v | APIC_LVT_MASKED);
    + apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
    }
    /*
    * Careful: we have to set masks only first to deassert
    * any level-triggered sources.
    */
    v = apic_read(APIC_LVTT);
    - apic_write_around(APIC_LVTT, v | APIC_LVT_MASKED);
    + apic_write(APIC_LVTT, v | APIC_LVT_MASKED);
    v = apic_read(APIC_LVT0);
    - apic_write_around(APIC_LVT0, v | APIC_LVT_MASKED);
    + apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
    v = apic_read(APIC_LVT1);
    - apic_write_around(APIC_LVT1, v | APIC_LVT_MASKED);
    + apic_write(APIC_LVT1, v | APIC_LVT_MASKED);
    if (maxlvt >= 4) {
    v = apic_read(APIC_LVTPC);
    - apic_write_around(APIC_LVTPC, v | APIC_LVT_MASKED);
    + apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
    }

    /* lets not touch this if we didn't frob it */
    #ifdef CONFIG_X86_MCE_P4THERMAL
    if (maxlvt >= 5) {
    v = apic_read(APIC_LVTTHMR);
    - apic_write_around(APIC_LVTTHMR, v | APIC_LVT_MASKED);
    + apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
    }
    #endif
    /*
    * Clean APIC state for other OSs:
    */
    - apic_write_around(APIC_LVTT, APIC_LVT_MASKED);
    - apic_write_around(APIC_LVT0, APIC_LVT_MASKED);
    - apic_write_around(APIC_LVT1, APIC_LVT_MASKED);
    + apic_write(APIC_LVTT, APIC_LVT_MASKED);
    + apic_write(APIC_LVT0, APIC_LVT_MASKED);
    + apic_write(APIC_LVT1, APIC_LVT_MASKED);
    if (maxlvt >= 3)
    - apic_write_around(APIC_LVTERR, APIC_LVT_MASKED);
    + apic_write(APIC_LVTERR, APIC_LVT_MASKED);
    if (maxlvt >= 4)
    - apic_write_around(APIC_LVTPC, APIC_LVT_MASKED);
    + apic_write(APIC_LVTPC, APIC_LVT_MASKED);

    #ifdef CONFIG_X86_MCE_P4THERMAL
    if (maxlvt >= 5)
    - apic_write_around(APIC_LVTTHMR, APIC_LVT_MASKED);
    + apic_write(APIC_LVTTHMR, APIC_LVT_MASKED);
    #endif
    /* Integrated APIC (!82489DX) ? */
    if (lapic_is_integrated()) {
    @@ -756,7 +753,7 @@ void disable_local_APIC(void)
    */
    value = apic_read(APIC_SPIV);
    value &= ~APIC_SPIV_APIC_ENABLED;
    - apic_write_around(APIC_SPIV, value);
    + apic_write(APIC_SPIV, value);

    /*
    * When LAPIC was disabled by the BIOS and enabled by the kernel,
    @@ -865,8 +862,8 @@ void __init sync_Arb_IDs(void)
    apic_wait_icr_idle();

    apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
    - apic_write_around(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
    - | APIC_DM_INIT);
    + apic_write(APIC_ICR,
    + APIC_DEST_ALLINC | APIC_INT_LEVELTRIG | APIC_DM_INIT);
    }

    /*
    @@ -902,16 +899,16 @@ void __init init_bsp_APIC(void)
    else
    value |= APIC_SPIV_FOCUS_DISABLED;
    value |= SPURIOUS_APIC_VECTOR;
    - apic_write_around(APIC_SPIV, value);
    + apic_write(APIC_SPIV, value);

    /*
    * Set up the virtual wire mode.
    */
    - apic_write_around(APIC_LVT0, APIC_DM_EXTINT);
    + apic_write(APIC_LVT0, APIC_DM_EXTINT);
    value = APIC_DM_NMI;
    if (!lapic_is_integrated()) /* 82489DX */
    value |= APIC_LVT_LEVEL_TRIGGER;
    - apic_write_around(APIC_LVT1, value);
    + apic_write(APIC_LVT1, value);
    }

    static void __cpuinit lapic_setup_esr(void)
    @@ -926,7 +923,7 @@ static void __cpuinit lapic_setup_esr(vo

    /* enables sending errors */
    value = ERROR_APIC_VECTOR;
    - apic_write_around(APIC_LVTERR, value);
    + apic_write(APIC_LVTERR, value);
    /*
    * spec says clear errors after enabling vector.
    */
    @@ -989,7 +986,7 @@ void __cpuinit setup_local_APIC(void)
    */
    value = apic_read(APIC_TASKPRI);
    value &= ~APIC_TPRI_MASK;
    - apic_write_around(APIC_TASKPRI, value);
    + apic_write(APIC_TASKPRI, value);

    /*
    * After a crash, we no longer service the interrupts and a pending
    @@ -1047,7 +1044,7 @@ void __cpuinit setup_local_APIC(void)
    * Set spurious IRQ vector
    */
    value |= SPURIOUS_APIC_VECTOR;
    - apic_write_around(APIC_SPIV, value);
    + apic_write(APIC_SPIV, value);

    /*
    * Set up LVT0, LVT1:
    @@ -1069,7 +1066,7 @@ void __cpuinit setup_local_APIC(void)
    apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
    smp_processor_id());
    }
    - apic_write_around(APIC_LVT0, value);
    + apic_write(APIC_LVT0, value);

    /*
    * only the BP should see the LINT1 NMI signal, obviously.
    @@ -1080,7 +1077,7 @@ void __cpuinit setup_local_APIC(void)
    value = APIC_DM_NMI | APIC_LVT_MASKED;
    if (!integrated) /* 82489DX */
    value |= APIC_LVT_LEVEL_TRIGGER;
    - apic_write_around(APIC_LVT1, value);
    + apic_write(APIC_LVT1, value);
    }

    void __cpuinit end_local_APIC_setup(void)
    @@ -1091,7 +1088,7 @@ void __cpuinit end_local_APIC_setup(void
    /* Disable the local apic timer */
    value = apic_read(APIC_LVTT);
    value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
    - apic_write_around(APIC_LVTT, value);
    + apic_write(APIC_LVTT, value);

    setup_apic_nmi_watchdog(NULL);
    apic_pm_activate();
    @@ -1419,7 +1416,7 @@ void disconnect_bsp_APIC(int virt_wire_s
    value &= ~APIC_VECTOR_MASK;
    value |= APIC_SPIV_APIC_ENABLED;
    value |= 0xf;
    - apic_write_around(APIC_SPIV, value);
    + apic_write(APIC_SPIV, value);

    if (!virt_wire_setup) {
    /*
    @@ -1432,10 +1429,10 @@ void disconnect_bsp_APIC(int virt_wire_s
    APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
    value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
    value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
    - apic_write_around(APIC_LVT0, value);
    + apic_write(APIC_LVT0, value);
    } else {
    /* Disable LVT0 */
    - apic_write_around(APIC_LVT0, APIC_LVT_MASKED);
    + apic_write(APIC_LVT0, APIC_LVT_MASKED);
    }

    /*
    @@ -1449,7 +1446,7 @@ void disconnect_bsp_APIC(int virt_wire_s
    APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
    value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
    value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
    - apic_write_around(APIC_LVT1, value);
    + apic_write(APIC_LVT1, value);
    }
    }

    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/cpu/bugs.c linux-next-2.6.26-rc9-20080711/arch/x86/kernel/cpu/bugs.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/cpu/bugs.c 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/kernel/cpu/bugs.c 2008-07-16 13:55:47.000000000 +0000
    @@ -131,13 +131,7 @@ static void __init check_popad(void)
    * (for due to lack of "invlpg" and working WP on a i386)
    * - In order to run on anything without a TSC, we need to be
    * compiled for a i486.
    - * - In order to support the local APIC on a buggy Pentium machine,
    - * we need to be compiled with CONFIG_X86_GOOD_APIC disabled,
    - * which happens implicitly if compiled for a Pentium or lower
    - * (unless an advanced selection of CPU features is used) as an
    - * otherwise config implies a properly working local APIC without
    - * the need to do extra reads from the APIC.
    -*/
    + */

    static void __init check_config(void)
    {
    @@ -151,21 +145,6 @@ static void __init check_config(void)
    if (boot_cpu_data.x86 == 3)
    panic("Kernel requires i486+ for 'invlpg' and other features");
    #endif
    -
    -/*
    - * If we were told we had a good local APIC, check for buggy Pentia,
    - * i.e. all B steppings and the C2 stepping of P54C when using their
    - * integrated APIC (see 11AP erratum in "Pentium Processor
    - * Specification Update").
    - */
    -#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_GOOD_APIC)
    - if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL
    - && cpu_has_apic
    - && boot_cpu_data.x86 == 5
    - && boot_cpu_data.x86_model == 2
    - && (boot_cpu_data.x86_mask < 6 || boot_cpu_data.x86_mask == 11))
    - panic("Kernel compiled for PMMX+, assumes a local APIC without the read-before-write bug!");
    -#endif
    }


    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/cpu/intel.c linux-next-2.6.26-rc9-20080711/arch/x86/kernel/cpu/intel.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/cpu/intel.c 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/kernel/cpu/intel.c 2008-07-16 13:53:45.000000000 +0000
    @@ -226,6 +226,16 @@ static void __cpuinit init_intel(struct

    if (cpu_has_bts)
    ds_init_intel(c);
    +
    + /*
    + * See if we have a good local APIC by checking for buggy Pentia,
    + * i.e. all B steppings and the C2 stepping of P54C when using their
    + * integrated APIC (see 11AP erratum in "Pentium Processor
    + * Specification Update").
    + */
    + if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
    + (c->x86_mask < 0x6 || c->x86_mask == 0xb))
    + set_cpu_cap(c, X86_FEATURE_11AP);
    }

    static unsigned int __cpuinit intel_size_cache(struct cpuinfo_x86 *c, unsigned int size)
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/cpu/mcheck/p4.c linux-next-2.6.26-rc9-20080711/arch/x86/kernel/cpu/mcheck/p4.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/cpu/mcheck/p4.c 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/kernel/cpu/mcheck/p4.c 2008-07-16 14:43:47.000000000 +0000
    @@ -102,7 +102,7 @@ static void intel_init_thermal(struct cp
    /* The temperature transition interrupt handler setup */
    h = THERMAL_APIC_VECTOR; /* our delivery vector */
    h |= (APIC_DM_FIXED | APIC_LVT_MASKED); /* we'll mask till we're ready */
    - apic_write_around(APIC_LVTTHMR, h);
    + apic_write(APIC_LVTTHMR, h);

    rdmsr(MSR_IA32_THERM_INTERRUPT, l, h);
    wrmsr(MSR_IA32_THERM_INTERRUPT, l | 0x03 , h);
    @@ -114,7 +114,7 @@ static void intel_init_thermal(struct cp
    wrmsr(MSR_IA32_MISC_ENABLE, l | (1<<3), h);

    l = apic_read(APIC_LVTTHMR);
    - apic_write_around(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
    + apic_write(APIC_LVTTHMR, l & ~APIC_LVT_MASKED);
    printk(KERN_INFO "CPU%d: Thermal monitoring enabled\n", cpu);

    /* enable thermal throttle processing */
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/io_apic_32.c linux-next-2.6.26-rc9-20080711/arch/x86/kernel/io_apic_32.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/io_apic_32.c 2008-07-14 16:59:41.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/kernel/io_apic_32.c 2008-07-16 15:04:33.000000000 +0000
    @@ -763,7 +763,7 @@ void send_IPI_self(int vector)
    /*
    * Send the IPI. The write to APIC_ICR fires this off.
    */
    - apic_write_around(APIC_ICR, cfg);
    + apic_write(APIC_ICR, cfg);
    }
    #endif /* !CONFIG_SMP */

    @@ -2037,7 +2037,7 @@ static void mask_lapic_irq(unsigned int
    unsigned long v;

    v = apic_read(APIC_LVT0);
    - apic_write_around(APIC_LVT0, v | APIC_LVT_MASKED);
    + apic_write(APIC_LVT0, v | APIC_LVT_MASKED);
    }

    static void unmask_lapic_irq(unsigned int irq)
    @@ -2045,7 +2045,7 @@ static void unmask_lapic_irq(unsigned in
    unsigned long v;

    v = apic_read(APIC_LVT0);
    - apic_write_around(APIC_LVT0, v & ~APIC_LVT_MASKED);
    + apic_write(APIC_LVT0, v & ~APIC_LVT_MASKED);
    }

    static struct irq_chip lapic_chip __read_mostly = {
    @@ -2175,7 +2175,7 @@ static inline void __init check_timer(vo
    * The AEOI mode will finish them in the 8259A
    * automatically.
    */
    - apic_write_around(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
    + apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
    init_8259A(1);
    timer_ack = (nmi_watchdog == NMI_IO_APIC && !APIC_INTEGRATED(ver));

    @@ -2270,7 +2270,7 @@ static inline void __init check_timer(vo
    "...trying to set up timer as Virtual Wire IRQ...\n");

    lapic_register_intr(0, vector);
    - apic_write_around(APIC_LVT0, APIC_DM_FIXED | vector); /* Fixed mode */
    + apic_write(APIC_LVT0, APIC_DM_FIXED | vector); /* Fixed mode */
    enable_8259A_irq(0);

    if (timer_irq_works()) {
    @@ -2278,7 +2278,7 @@ static inline void __init check_timer(vo
    goto out;
    }
    disable_8259A_irq(0);
    - apic_write_around(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_FIXED | vector);
    + apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_FIXED | vector);
    apic_printk(APIC_QUIET, KERN_INFO "..... failed.\n");

    apic_printk(APIC_QUIET, KERN_INFO
    @@ -2286,7 +2286,7 @@ static inline void __init check_timer(vo

    init_8259A(0);
    make_8259A_irq(0);
    - apic_write_around(APIC_LVT0, APIC_DM_EXTINT);
    + apic_write(APIC_LVT0, APIC_DM_EXTINT);

    unlock_ExtINT_logic();

    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/ipi.c linux-next-2.6.26-rc9-20080711/arch/x86/kernel/ipi.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/ipi.c 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/kernel/ipi.c 2008-07-16 14:46:12.000000000 +0000
    @@ -70,7 +70,7 @@ void __send_IPI_shortcut(unsigned int sh
    /*
    * Send the IPI. The write to APIC_ICR fires this off.
    */
    - apic_write_around(APIC_ICR, cfg);
    + apic_write(APIC_ICR, cfg);
    }

    void send_IPI_self(int vector)
    @@ -98,7 +98,7 @@ static inline void __send_IPI_dest_field
    * prepare target chip field
    */
    cfg = __prepare_ICR2(mask);
    - apic_write_around(APIC_ICR2, cfg);
    + apic_write(APIC_ICR2, cfg);

    /*
    * program the ICR
    @@ -108,7 +108,7 @@ static inline void __send_IPI_dest_field
    /*
    * Send the IPI. The write to APIC_ICR fires this off.
    */
    - apic_write_around(APIC_ICR, cfg);
    + apic_write(APIC_ICR, cfg);
    }

    /*
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/nmi.c linux-next-2.6.26-rc9-20080711/arch/x86/kernel/nmi.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/nmi.c 2008-07-13 02:18:46.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/kernel/nmi.c 2008-07-16 14:46:23.000000000 +0000
    @@ -260,7 +260,7 @@ late_initcall(init_lapic_nmi_sysfs);

    static void __acpi_nmi_enable(void *__unused)
    {
    - apic_write_around(APIC_LVT0, APIC_DM_NMI);
    + apic_write(APIC_LVT0, APIC_DM_NMI);
    }

    /*
    @@ -274,7 +274,7 @@ void acpi_nmi_enable(void)

    static void __acpi_nmi_disable(void *__unused)
    {
    - apic_write_around(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
    + apic_write(APIC_LVT0, APIC_DM_NMI | APIC_LVT_MASKED);
    }

    /*
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/paravirt.c linux-next-2.6.26-rc9-20080711/arch/x86/kernel/paravirt.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/paravirt.c 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/kernel/paravirt.c 2008-07-16 14:31:05.000000000 +0000
    @@ -361,7 +361,6 @@ struct pv_cpu_ops pv_cpu_ops = {
    struct pv_apic_ops pv_apic_ops = {
    #ifdef CONFIG_X86_LOCAL_APIC
    .apic_write = native_apic_write,
    - .apic_write_atomic = native_apic_write_atomic,
    .apic_read = native_apic_read,
    .setup_boot_clock = setup_boot_APIC_clock,
    .setup_secondary_clock = setup_secondary_APIC_clock,
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/smpboot.c linux-next-2.6.26-rc9-20080711/arch/x86/kernel/smpboot.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/smpboot.c 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/kernel/smpboot.c 2008-07-16 14:38:23.000000000 +0000
    @@ -546,8 +546,8 @@ static inline void __inquire_remote_apic
    printk(KERN_CONT
    "a previous APIC delivery may have failed\n");

    - apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
    - apic_write_around(APIC_ICR, APIC_DM_REMRD | regs[i]);
    + apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(apicid));
    + apic_write(APIC_ICR, APIC_DM_REMRD | regs[i]);

    timeout = 0;
    do {
    @@ -579,11 +579,11 @@ wakeup_secondary_cpu(int logical_apicid,
    int maxlvt;

    /* Target chip */
    - apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(logical_apicid));
    + apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(logical_apicid));

    /* Boot on the stack */
    /* Kick the second */
    - apic_write_around(APIC_ICR, APIC_DM_NMI | APIC_DEST_LOGICAL);
    + apic_write(APIC_ICR, APIC_DM_NMI | APIC_DEST_LOGICAL);

    Dprintk("Waiting for send to finish...\n");
    send_status = safe_apic_wait_icr_idle();
    @@ -592,14 +592,9 @@ wakeup_secondary_cpu(int logical_apicid,
    * Give the other CPU some time to accept the IPI.
    */
    udelay(200);
    - /*
    - * Due to the Pentium erratum 3AP.
    - */
    maxlvt = lapic_get_maxlvt();
    - if (maxlvt > 3) {
    - apic_read_around(APIC_SPIV);
    + if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
    apic_write(APIC_ESR, 0);
    - }
    accept_status = (apic_read(APIC_ESR) & 0xEF);
    Dprintk("NMI sent.\n");

    @@ -625,12 +620,14 @@ wakeup_secondary_cpu(int phys_apicid, un
    return send_status;
    }

    + maxlvt = lapic_get_maxlvt();
    +
    /*
    * Be paranoid about clearing APIC errors.
    */
    if (APIC_INTEGRATED(apic_version[phys_apicid])) {
    - apic_read_around(APIC_SPIV);
    - apic_write(APIC_ESR, 0);
    + if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
    + apic_write(APIC_ESR, 0);
    apic_read(APIC_ESR);
    }

    @@ -639,13 +636,13 @@ wakeup_secondary_cpu(int phys_apicid, un
    /*
    * Turn INIT on target chip
    */
    - apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
    + apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));

    /*
    * Send IPI
    */
    - apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_INT_ASSERT
    - | APIC_DM_INIT);
    + apic_write(APIC_ICR,
    + APIC_INT_LEVELTRIG | APIC_INT_ASSERT | APIC_DM_INIT);

    Dprintk("Waiting for send to finish...\n");
    send_status = safe_apic_wait_icr_idle();
    @@ -655,10 +652,10 @@ wakeup_secondary_cpu(int phys_apicid, un
    Dprintk("Deasserting INIT.\n");

    /* Target chip */
    - apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
    + apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));

    /* Send IPI */
    - apic_write_around(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);
    + apic_write(APIC_ICR, APIC_INT_LEVELTRIG | APIC_DM_INIT);

    Dprintk("Waiting for send to finish...\n");
    send_status = safe_apic_wait_icr_idle();
    @@ -689,12 +686,10 @@ wakeup_secondary_cpu(int phys_apicid, un
    */
    Dprintk("#startup loops: %d.\n", num_starts);

    - maxlvt = lapic_get_maxlvt();
    -
    for (j = 1; j <= num_starts; j++) {
    Dprintk("Sending STARTUP #%d.\n", j);
    - apic_read_around(APIC_SPIV);
    - apic_write(APIC_ESR, 0);
    + if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
    + apic_write(APIC_ESR, 0);
    apic_read(APIC_ESR);
    Dprintk("After apic_write.\n");

    @@ -703,12 +698,11 @@ wakeup_secondary_cpu(int phys_apicid, un
    */

    /* Target chip */
    - apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));
    + apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(phys_apicid));

    /* Boot on the stack */
    /* Kick the second */
    - apic_write_around(APIC_ICR, APIC_DM_STARTUP
    - | (start_eip >> 12));
    + apic_write(APIC_ICR, APIC_DM_STARTUP | (start_eip >> 12));

    /*
    * Give the other CPU some time to accept the IPI.
    @@ -724,13 +718,8 @@ wakeup_secondary_cpu(int phys_apicid, un
    * Give the other CPU some time to accept the IPI.
    */
    udelay(200);
    - /*
    - * Due to the Pentium erratum 3AP.
    - */
    - if (maxlvt > 3) {
    - apic_read_around(APIC_SPIV);
    + if (maxlvt > 3) /* Due to the Pentium erratum 3AP. */
    apic_write(APIC_ESR, 0);
    - }
    accept_status = (apic_read(APIC_ESR) & 0xEF);
    if (send_status || accept_status)
    break;
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/vmi_32.c linux-next-2.6.26-rc9-20080711/arch/x86/kernel/vmi_32.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/kernel/vmi_32.c 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/kernel/vmi_32.c 2008-07-16 14:30:19.000000000 +0000
    @@ -906,7 +906,6 @@ static inline int __init activate_vmi(vo
    #ifdef CONFIG_X86_LOCAL_APIC
    para_fill(pv_apic_ops.apic_read, APICRead);
    para_fill(pv_apic_ops.apic_write, APICWrite);
    - para_fill(pv_apic_ops.apic_write_atomic, APICWrite);
    #endif

    /*
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/lguest/boot.c linux-next-2.6.26-rc9-20080711/arch/x86/lguest/boot.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/lguest/boot.c 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/lguest/boot.c 2008-07-16 14:29:55.000000000 +0000
    @@ -991,7 +991,6 @@ __init void lguest_init(void)
    #ifdef CONFIG_X86_LOCAL_APIC
    /* apic read/write intercepts */
    pv_apic_ops.apic_write = lguest_apic_write;
    - pv_apic_ops.apic_write_atomic = lguest_apic_write;
    pv_apic_ops.apic_read = lguest_apic_read;
    #endif

    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/arch/x86/xen/enlighten.c linux-next-2.6.26-rc9-20080711/arch/x86/xen/enlighten.c
    --- linux-next-2.6.26-rc9-20080711.macro/arch/x86/xen/enlighten.c 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/arch/x86/xen/enlighten.c 2008-07-16 14:29:32.000000000 +0000
    @@ -1131,7 +1131,6 @@ static const struct pv_irq_ops xen_irq_o
    static const struct pv_apic_ops xen_apic_ops __initdata = {
    #ifdef CONFIG_X86_LOCAL_APIC
    .apic_write = xen_apic_write,
    - .apic_write_atomic = xen_apic_write,
    .apic_read = xen_apic_read,
    .setup_boot_clock = paravirt_nop,
    .setup_secondary_clock = paravirt_nop,
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/apic.h linux-next-2.6.26-rc9-20080711/include/asm-x86/apic.h
    --- linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/apic.h 2008-07-16 14:50:07.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/include/asm-x86/apic.h 2008-07-16 16:42:03.000000000 +0000
    @@ -3,6 +3,8 @@

    #include
    #include
    +
    +#include
    #include
    #include
    #include
    @@ -48,7 +50,6 @@ extern int disable_apic;
    #include
    #else
    #define apic_write native_apic_write
    -#define apic_write_atomic native_apic_write_atomic
    #define apic_read native_apic_read
    #define setup_boot_clock setup_boot_APIC_clock
    #define setup_secondary_clock setup_secondary_APIC_clock
    @@ -58,12 +59,11 @@ extern int is_vsmp_box(void);

    static inline void native_apic_write(unsigned long reg, u32 v)
    {
    - *((volatile u32 *)(APIC_BASE + reg)) = v;
    -}
    -
    -static inline void native_apic_write_atomic(unsigned long reg, u32 v)
    -{
    - (void)xchg((u32 *)(APIC_BASE + reg), v);
    + volatile u32 *addr = (volatile u32 *)(APIC_BASE + reg);
    +
    + alternative_io("movl %0, %1", "xchgl %0, %1", X86_FEATURE_11AP,
    + ASM_OUTPUT2("=r" (v), "=m" (*addr)),
    + ASM_OUTPUT2("0" (v), "m" (*addr)));
    }

    static inline u32 native_apic_read(unsigned long reg)
    @@ -75,16 +75,6 @@ extern void apic_wait_icr_idle(void);
    extern u32 safe_apic_wait_icr_idle(void);
    extern int get_physical_broadcast(void);

    -#ifdef CONFIG_X86_GOOD_APIC
    -# define FORCE_READ_AROUND_WRITE 0
    -# define apic_read_around(x)
    -# define apic_write_around(x, y) apic_write((x), (y))
    -#else
    -# define FORCE_READ_AROUND_WRITE 1
    -# define apic_read_around(x) apic_read(x)
    -# define apic_write_around(x, y) apic_write_atomic((x), (y))
    -#endif
    -
    static inline void ack_APIC_irq(void)
    {
    /*
    @@ -95,7 +85,7 @@ static inline void ack_APIC_irq(void)
    */

    /* Docs say use 0 for future compatibility */
    - apic_write_around(APIC_EOI, 0);
    + apic_write(APIC_EOI, 0);
    }

    extern int lapic_get_maxlvt(void);
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/cpufeature.h linux-next-2.6.26-rc9-20080711/include/asm-x86/cpufeature.h
    --- linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/cpufeature.h 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/include/asm-x86/cpufeature.h 2008-07-16 13:48:24.000000000 +0000
    @@ -79,6 +79,7 @@
    #define X86_FEATURE_REP_GOOD (3*32+16) /* rep microcode works well on this CPU */
    #define X86_FEATURE_MFENCE_RDTSC (3*32+17) /* Mfence synchronizes RDTSC */
    #define X86_FEATURE_LFENCE_RDTSC (3*32+18) /* Lfence synchronizes RDTSC */
    +#define X86_FEATURE_11AP (3*32+19) /* Bad local APIC aka 11AP */

    /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
    #define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/mach-bigsmp/mach_apic.h linux-next-2.6.26-rc9-20080711/include/asm-x86/mach-bigsmp/mach_apic.h
    --- linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/mach-bigsmp/mach_apic.h 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/include/asm-x86/mach-bigsmp/mach_apic.h 2008-07-16 14:46:34.000000000 +0000
    @@ -63,9 +63,9 @@ static inline void init_apic_ldr(void)
    unsigned long val;
    int cpu = smp_processor_id();

    - apic_write_around(APIC_DFR, APIC_DFR_VALUE);
    + apic_write(APIC_DFR, APIC_DFR_VALUE);
    val = calculate_ldr(cpu);
    - apic_write_around(APIC_LDR, val);
    + apic_write(APIC_LDR, val);
    }

    static inline void setup_apic_routing(void)
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/mach-default/mach_apic.h linux-next-2.6.26-rc9-20080711/include/asm-x86/mach-default/mach_apic.h
    --- linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/mach-default/mach_apic.h 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/include/asm-x86/mach-default/mach_apic.h 2008-07-16 14:46:49.000000000 +0000
    @@ -46,10 +46,10 @@ static inline void init_apic_ldr(void)
    {
    unsigned long val;

    - apic_write_around(APIC_DFR, APIC_DFR_VALUE);
    + apic_write(APIC_DFR, APIC_DFR_VALUE);
    val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
    val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
    - apic_write_around(APIC_LDR, val);
    + apic_write(APIC_LDR, val);
    }

    static inline int apic_id_registered(void)
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/mach-es7000/mach_apic.h linux-next-2.6.26-rc9-20080711/include/asm-x86/mach-es7000/mach_apic.h
    --- linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/mach-es7000/mach_apic.h 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/include/asm-x86/mach-es7000/mach_apic.h 2008-07-16 14:47:00.000000000 +0000
    @@ -66,9 +66,9 @@ static inline void init_apic_ldr(void)
    unsigned long val;
    int cpu = smp_processor_id();

    - apic_write_around(APIC_DFR, APIC_DFR_VALUE);
    + apic_write(APIC_DFR, APIC_DFR_VALUE);
    val = calculate_ldr(cpu);
    - apic_write_around(APIC_LDR, val);
    + apic_write(APIC_LDR, val);
    }

    #ifndef CONFIG_X86_GENERICARCH
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/mach-summit/mach_apic.h linux-next-2.6.26-rc9-20080711/include/asm-x86/mach-summit/mach_apic.h
    --- linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/mach-summit/mach_apic.h 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/include/asm-x86/mach-summit/mach_apic.h 2008-07-16 14:47:17.000000000 +0000
    @@ -63,10 +63,10 @@ static inline void init_apic_ldr(void)
    * BIOS puts 5 CPUs in one APIC cluster, we're hosed. */
    BUG_ON(count >= XAPIC_DEST_CPUS_SHIFT);
    id = my_cluster | (1UL << count);
    - apic_write_around(APIC_DFR, APIC_DFR_VALUE);
    + apic_write(APIC_DFR, APIC_DFR_VALUE);
    val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
    val |= SET_APIC_LOGICAL_ID(id);
    - apic_write_around(APIC_LDR, val);
    + apic_write(APIC_LDR, val);
    }

    static inline int multi_timer_check(int apic, int irq)
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/mach-visws/mach_apic.h linux-next-2.6.26-rc9-20080711/include/asm-x86/mach-visws/mach_apic.h
    --- linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/mach-visws/mach_apic.h 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/include/asm-x86/mach-visws/mach_apic.h 2008-07-16 14:47:31.000000000 +0000
    @@ -37,10 +37,10 @@ static inline void init_apic_ldr(void)
    {
    unsigned long val;

    - apic_write_around(APIC_DFR, APIC_DFR_VALUE);
    + apic_write(APIC_DFR, APIC_DFR_VALUE);
    val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
    val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
    - apic_write_around(APIC_LDR, val);
    + apic_write(APIC_LDR, val);
    }

    static inline void summit_check(char *oem, char *productid)
    diff -up --recursive --new-file linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/paravirt.h linux-next-2.6.26-rc9-20080711/include/asm-x86/paravirt.h
    --- linux-next-2.6.26-rc9-20080711.macro/include/asm-x86/paravirt.h 2008-07-16 16:37:51.000000000 +0000
    +++ linux-next-2.6.26-rc9-20080711/include/asm-x86/paravirt.h 2008-07-16 14:28:39.000000000 +0000
    @@ -205,7 +205,6 @@ struct pv_apic_ops {
    * these shouldn't be in this interface.
    */
    void (*apic_write)(unsigned long reg, u32 v);
    - void (*apic_write_atomic)(unsigned long reg, u32 v);
    u32 (*apic_read)(unsigned long reg);
    void (*setup_boot_clock)(void);
    void (*setup_secondary_clock)(void);
    @@ -896,11 +895,6 @@ static inline void apic_write(unsigned l
    PVOP_VCALL2(pv_apic_ops.apic_write, reg, v);
    }

    -static inline void apic_write_atomic(unsigned long reg, u32 v)
    -{
    - PVOP_VCALL2(pv_apic_ops.apic_write_atomic, reg, v);
    -}
    -
    static inline u32 apic_read(unsigned long reg)
    {
    return PVOP_CALL1(unsigned long, pv_apic_ops.apic_read, reg);
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  2. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives


    * Maciej W. Rozycki wrote:

    > Use alternatives to select the workaround for the 11AP Pentium
    > erratum for the affected steppings on the fly rather than build time.
    > Remove the X86_GOOD_APIC configuration option and replace all the
    > calls to apic_write_around() with plain apic_write(), protecting
    > accesses to the ESR as appropriate due to the 3AP Pentium erratum.
    > Remove apic_read_around() and all its invocations altogether as not
    > needed. Remove apic_write_atomic() and all its implementing backends.
    > The use of ASM_OUTPUT2() is not strictly needed for input constraints,
    > but I have used it for readability's sake.


    wow, impressive patch!

    > I had the feeling no one else was brave enough to do it, so I went
    > ahead and here it is. Verified by checking the generated assembly and
    > tested with both a 32-bit and a 64-bit configuration, also with the
    > 11AP "feature" forced on and verified with gdb on /proc/kcore to work
    > as expected (as an 11AP machines are quite hard to get hands on these
    > days). Some script complained about the use of "volatile", but
    > apic_write() needs it for the same reason and is effectively a
    > replacement for writel(), so I have disregarded it.


    kudos for pulling this off :-)

    applied to tip/x86/apic. This will interact with tip/x86/x2apic but that
    topic is being worked on anyway. The interaction should be trivial.

    Ingo
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  3. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, Jul 18, 2008 at 3:52 AM, Ingo Molnar wrote:
    >
    > * Maciej W. Rozycki wrote:
    >
    >> Use alternatives to select the workaround for the 11AP Pentium
    >> erratum for the affected steppings on the fly rather than build time.
    >> Remove the X86_GOOD_APIC configuration option and replace all the
    >> calls to apic_write_around() with plain apic_write(), protecting
    >> accesses to the ESR as appropriate due to the 3AP Pentium erratum.
    >> Remove apic_read_around() and all its invocations altogether as not
    >> needed. Remove apic_write_atomic() and all its implementing backends.
    >> The use of ASM_OUTPUT2() is not strictly needed for input constraints,
    >> but I have used it for readability's sake.

    >
    > wow, impressive patch!
    >
    >> I had the feeling no one else was brave enough to do it, so I went
    >> ahead and here it is. Verified by checking the generated assembly and
    >> tested with both a 32-bit and a 64-bit configuration, also with the
    >> 11AP "feature" forced on and verified with gdb on /proc/kcore to work
    >> as expected (as an 11AP machines are quite hard to get hands on these
    >> days). Some script complained about the use of "volatile", but
    >> apic_write() needs it for the same reason and is effectively a
    >> replacement for writel(), so I have disregarded it.

    >
    > kudos for pulling this off :-)
    >
    > applied to tip/x86/apic. This will interact with tip/x86/x2apic but that
    > topic is being worked on anyway. The interaction should be trivial.


    it seems we should start apic related merging after x2apic get merged?

    YH
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  4. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, Jul 18, 2008 at 9:25 AM, Yinghai Lu wrote:
    > On Fri, Jul 18, 2008 at 3:52 AM, Ingo Molnar wrote:
    >>
    >> * Maciej W. Rozycki wrote:
    >>
    >>> Use alternatives to select the workaround for the 11AP Pentium
    >>> erratum for the affected steppings on the fly rather than build time.
    >>> Remove the X86_GOOD_APIC configuration option and replace all the
    >>> calls to apic_write_around() with plain apic_write(), protecting
    >>> accesses to the ESR as appropriate due to the 3AP Pentium erratum.
    >>> Remove apic_read_around() and all its invocations altogether as not
    >>> needed. Remove apic_write_atomic() and all its implementing backends.
    >>> The use of ASM_OUTPUT2() is not strictly needed for input constraints,
    >>> but I have used it for readability's sake.

    >>
    >> wow, impressive patch!
    >>
    >>> I had the feeling no one else was brave enough to do it, so I went
    >>> ahead and here it is. Verified by checking the generated assembly and
    >>> tested with both a 32-bit and a 64-bit configuration, also with the
    >>> 11AP "feature" forced on and verified with gdb on /proc/kcore to work
    >>> as expected (as an 11AP machines are quite hard to get hands on these
    >>> days). Some script complained about the use of "volatile", but
    >>> apic_write() needs it for the same reason and is effectively a
    >>> replacement for writel(), so I have disregarded it.

    >>
    >> kudos for pulling this off :-)
    >>
    >> applied to tip/x86/apic. This will interact with tip/x86/x2apic but that
    >> topic is being worked on anyway. The interaction should be trivial.

    >
    > it seems we should start apic related merging after x2apic get merged?
    >


    > git merge tip/x86/x2apic

    Auto-merged Documentation/kernel-parameters.txt
    Auto-merged arch/x86/Kconfig
    Auto-merged arch/x86/kernel/Makefile
    CONFLICT (content): Merge conflict in arch/x86/kernel/Makefile
    Auto-merged arch/x86/kernel/acpi/boot.c
    Auto-merged arch/x86/kernel/apic_32.c
    Auto-merged arch/x86/kernel/apic_64.c
    Auto-merged arch/x86/kernel/cpu/common_64.c
    Auto-merged arch/x86/kernel/genx2apic_uv_x.c
    Auto-merged arch/x86/kernel/io_apic_32.c
    Auto-merged arch/x86/kernel/io_apic_64.c
    Auto-merged arch/x86/kernel/paravirt.c
    CONFLICT (content): Merge conflict in arch/x86/kernel/paravirt.c
    Auto-merged arch/x86/kernel/setup.c
    Auto-merged arch/x86/kernel/smpboot.c
    CONFLICT (content): Merge conflict in arch/x86/kernel/smpboot.c
    Auto-merged arch/x86/kernel/vmi_32.c
    CONFLICT (content): Merge conflict in arch/x86/kernel/vmi_32.c
    Auto-merged arch/x86/lguest/boot.c
    Auto-merged arch/x86/xen/enlighten.c
    CONFLICT (content): Merge conflict in arch/x86/xen/enlighten.c
    Auto-merged drivers/pci/Makefile
    Auto-merged drivers/pci/intel-iommu.c
    Auto-merged include/asm-x86/apic.h
    CONFLICT (content): Merge conflict in include/asm-x86/apic.h
    Auto-merged include/asm-x86/cpufeature.h
    Auto-merged include/asm-x86/genapic_64.h
    Auto-merged include/asm-x86/hw_irq.h
    Auto-merged include/asm-x86/io_apic.h
    Auto-merged include/asm-x86/ipi.h
    Auto-merged include/asm-x86/mach-default/mach_apic.h
    Auto-merged include/asm-x86/mach-es7000/mach_apic.h
    Auto-merged include/asm-x86/paravirt.h
    CONFLICT (content): Merge conflict in include/asm-x86/paravirt.h
    Auto-merged include/asm-x86/smp.h
    Auto-merged include/linux/irq.h
    Auto-merged kernel/irq/manage.c
    Automatic merge failed; fix conflicts and then commit the result.

    also please apply
    Fix VMI apic_ops.
    from Suresh

    to x2apic

    YH
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  5. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, Jul 18, 2008 at 2:03 PM, Ingo Molnar wrote:
    >
    > * Yinghai Lu wrote:
    >
    >> > git merge tip/x86/x2apic

    >> CONFLICT (content): Merge conflict in arch/x86/kernel/Makefile
    >> CONFLICT (content): Merge conflict in arch/x86/kernel/paravirt.c
    >> CONFLICT (content): Merge conflict in arch/x86/kernel/smpboot.c
    >> CONFLICT (content): Merge conflict in arch/x86/kernel/vmi_32.c
    >> CONFLICT (content): Merge conflict in arch/x86/xen/enlighten.c
    >> CONFLICT (content): Merge conflict in include/asm-x86/apic.h
    >> CONFLICT (content): Merge conflict in include/asm-x86/paravirt.h

    >
    > that's due to the changes in tip/x86/apic and in tip/x86/uv.
    >
    > ok, i've just merged x86/apic into x86/x2apic and x86/uv as well, and
    > pushed out the result.
    >
    > Note: it's a first raw merge and completely untested. It will now merge
    > cleanly into tip/master. There are probably a few details missing.
    >
    > The smp-alternatives based trick that Maciej applied for write-around
    > can stay in the mem_apic_* methods - modern APICs do not need any
    > workaround in this area and can just use apic_ops.


    CC arch/x86/kernel/apic_64.o
    arch/x86/kernel/apic_64.c:170: error: unknown field 'write_atomic'
    specified in initializer
    arch/x86/kernel/apic_64.c:170: error: 'native_apic_mem_write_atomic'
    undeclared here (not in a function)
    arch/x86/kernel/apic_64.c:209: error: unknown field 'write_atomic'
    specified in initializer
    arch/x86/kernel/apic_64.c:209: warning: initialization from
    incompatible pointer type
    make[1]: *** [arch/x86/kernel/apic_64.o] Error 1
    make: *** [arch/x86/kernel] Error 2


    YH
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  6. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives


    * Yinghai Lu wrote:

    > > git merge tip/x86/x2apic

    > CONFLICT (content): Merge conflict in arch/x86/kernel/Makefile
    > CONFLICT (content): Merge conflict in arch/x86/kernel/paravirt.c
    > CONFLICT (content): Merge conflict in arch/x86/kernel/smpboot.c
    > CONFLICT (content): Merge conflict in arch/x86/kernel/vmi_32.c
    > CONFLICT (content): Merge conflict in arch/x86/xen/enlighten.c
    > CONFLICT (content): Merge conflict in include/asm-x86/apic.h
    > CONFLICT (content): Merge conflict in include/asm-x86/paravirt.h


    that's due to the changes in tip/x86/apic and in tip/x86/uv.

    ok, i've just merged x86/apic into x86/x2apic and x86/uv as well, and
    pushed out the result.

    Note: it's a first raw merge and completely untested. It will now merge
    cleanly into tip/master. There are probably a few details missing.

    The smp-alternatives based trick that Maciej applied for write-around
    can stay in the mem_apic_* methods - modern APICs do not need any
    workaround in this area and can just use apic_ops.

    > also please apply
    > Fix VMI apic_ops.
    > from Suresh
    >
    > to x2apic


    done.

    Ingo
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  7. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, 18 Jul 2008, Yinghai Lu wrote:

    > CC arch/x86/kernel/apic_64.o
    > arch/x86/kernel/apic_64.c:170: error: unknown field 'write_atomic'
    > specified in initializer
    > arch/x86/kernel/apic_64.c:170: error: 'native_apic_mem_write_atomic'
    > undeclared here (not in a function)
    > arch/x86/kernel/apic_64.c:209: error: unknown field 'write_atomic'
    > specified in initializer
    > arch/x86/kernel/apic_64.c:209: warning: initialization from
    > incompatible pointer type
    > make[1]: *** [arch/x86/kernel/apic_64.o] Error 1
    > make: *** [arch/x86/kernel] Error 2


    Just remove the offending initialisers. They are not needed anymore as
    the .write method is now used universally including places where
    ..write_atomic was. I just could not stand watching the thing
    proliferate...

    Maciej
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  8. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, 2008-07-18 at 15:02 -0700, Maciej W. Rozycki wrote:
    > On Fri, 18 Jul 2008, Yinghai Lu wrote:
    >
    > > CC arch/x86/kernel/apic_64.o
    > > arch/x86/kernel/apic_64.c:170: error: unknown field 'write_atomic'
    > > specified in initializer
    > > arch/x86/kernel/apic_64.c:170: error: 'native_apic_mem_write_atomic'
    > > undeclared here (not in a function)
    > > arch/x86/kernel/apic_64.c:209: error: unknown field 'write_atomic'
    > > specified in initializer
    > > arch/x86/kernel/apic_64.c:209: warning: initialization from
    > > incompatible pointer type
    > > make[1]: *** [arch/x86/kernel/apic_64.o] Error 1
    > > make: *** [arch/x86/kernel] Error 2

    >
    > Just remove the offending initialisers. They are not needed anymore as
    > the .write method is now used universally including places where
    > .write_atomic was. I just could not stand watching the thing
    > proliferate...


    Thank you for cleaning this up Yinghai, but this really begs the
    question - is having write_atomic REALLY worthwhile?

    Intel themselves have not supported the affected processors since
    October 17, 2000, and here we are writing code for it, when the last
    processor with such a flaw (C2 or cB1 stepping Pentium) was stamped in
    1995, over 13 years ago. It might have been relevant when Linus was
    developing SMP support in '96, but it isn't now.

    In fact, anyone running a 120 Mhz or 133 Mhz Pentium processor that has
    been obsoleted for 8 years should at this point be shot for wasting
    energy with their poor megawatt/megaflop ratio, doubly so if they can
    claim to be doing so in some kind of SMP scenario which even requires
    using an APIC at all.

    Seriously, please consider removing all of the flaming crap surrounding
    apic_write_around entirely and forcing users who compile for less than
    686 processors to just not have official support for local APIC at all,
    or just default it off and let people turn it on at own risk.

    Zach

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  9. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, Jul 18, 2008 at 03:42:17PM -0700, Zachary Amsden wrote:
    > On Fri, 2008-07-18 at 15:02 -0700, Maciej W. Rozycki wrote:
    > > On Fri, 18 Jul 2008, Yinghai Lu wrote:
    > >
    > > > CC arch/x86/kernel/apic_64.o
    > > > arch/x86/kernel/apic_64.c:170: error: unknown field 'write_atomic'
    > > > specified in initializer
    > > > arch/x86/kernel/apic_64.c:170: error: 'native_apic_mem_write_atomic'
    > > > undeclared here (not in a function)
    > > > arch/x86/kernel/apic_64.c:209: error: unknown field 'write_atomic'
    > > > specified in initializer
    > > > arch/x86/kernel/apic_64.c:209: warning: initialization from
    > > > incompatible pointer type
    > > > make[1]: *** [arch/x86/kernel/apic_64.o] Error 1
    > > > make: *** [arch/x86/kernel] Error 2

    > >
    > > Just remove the offending initialisers. They are not needed anymore as
    > > the .write method is now used universally including places where
    > > .write_atomic was. I just could not stand watching the thing
    > > proliferate...

    >
    > Thank you for cleaning this up Yinghai, but this really begs the
    > question - is having write_atomic REALLY worthwhile?


    And this thread is about, Maciej's cleanup patch which removed
    write_atomic completely

    Thanks to Maciej who posted this fix. It was on my todo list for
    sometime now!

    thanks,
    suresh
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  10. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, Jul 18, 2008 at 3:49 PM, Suresh Siddha
    wrote:
    > On Fri, Jul 18, 2008 at 03:42:17PM -0700, Zachary Amsden wrote:
    >> On Fri, 2008-07-18 at 15:02 -0700, Maciej W. Rozycki wrote:
    >> > On Fri, 18 Jul 2008, Yinghai Lu wrote:
    >> >
    >> > > CC arch/x86/kernel/apic_64.o
    >> > > arch/x86/kernel/apic_64.c:170: error: unknown field 'write_atomic'
    >> > > specified in initializer
    >> > > arch/x86/kernel/apic_64.c:170: error: 'native_apic_mem_write_atomic'
    >> > > undeclared here (not in a function)
    >> > > arch/x86/kernel/apic_64.c:209: error: unknown field 'write_atomic'
    >> > > specified in initializer
    >> > > arch/x86/kernel/apic_64.c:209: warning: initialization from
    >> > > incompatible pointer type
    >> > > make[1]: *** [arch/x86/kernel/apic_64.o] Error 1
    >> > > make: *** [arch/x86/kernel] Error 2
    >> >
    >> > Just remove the offending initialisers. They are not needed anymore as
    >> > the .write method is now used universally including places where
    >> > .write_atomic was. I just could not stand watching the thing
    >> > proliferate...

    >>
    >> Thank you for cleaning this up Yinghai, but this really begs the
    >> question - is having write_atomic REALLY worthwhile?

    >
    > And this thread is about, Maciej's cleanup patch which removed
    > write_atomic completely
    >
    > Thanks to Maciej who posted this fix. It was on my todo list for
    > sometime now!


    do we rebase tip/x86/x2apic or rework this patch?

    YH
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  11. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, Jul 18, 2008 at 02:03:48PM -0700, Ingo Molnar wrote:
    >
    > * Yinghai Lu wrote:
    >
    > > > git merge tip/x86/x2apic

    > > CONFLICT (content): Merge conflict in arch/x86/kernel/Makefile
    > > CONFLICT (content): Merge conflict in arch/x86/kernel/paravirt.c
    > > CONFLICT (content): Merge conflict in arch/x86/kernel/smpboot.c
    > > CONFLICT (content): Merge conflict in arch/x86/kernel/vmi_32.c
    > > CONFLICT (content): Merge conflict in arch/x86/xen/enlighten.c
    > > CONFLICT (content): Merge conflict in include/asm-x86/apic.h
    > > CONFLICT (content): Merge conflict in include/asm-x86/paravirt.h

    >
    > that's due to the changes in tip/x86/apic and in tip/x86/uv.
    >
    > ok, i've just merged x86/apic into x86/x2apic and x86/uv as well, and
    > pushed out the result.
    >
    > Note: it's a first raw merge and completely untested. It will now merge
    > cleanly into tip/master. There are probably a few details missing.


    Ingo, thanks for doing this. While I was testing my merge changes, you posted
    yours... anyhow we need this piece, which is missing from your merge.

    Signed-off-by: Suresh Siddha
    ---
    diff --git a/arch/x86/kernel/apic_32.c b/arch/x86/kernel/apic_32.c
    index dcb897f..8728f54 100644
    --- a/arch/x86/kernel/apic_32.c
    +++ b/arch/x86/kernel/apic_32.c
    @@ -174,8 +174,8 @@ u32 safe_xapic_wait_icr_idle(void)

    void xapic_icr_write(u32 low, u32 id)
    {
    - apic_write_around(APIC_ICR2, SET_APIC_DEST_FIELD(id));
    - apic_write_around(APIC_ICR, low);
    + apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
    + apic_write(APIC_ICR, low);
    }

    u64 xapic_icr_read(void)
    @@ -191,7 +191,6 @@ u64 xapic_icr_read(void)
    static struct apic_ops xapic_ops = {
    .read = native_apic_mem_read,
    .write = native_apic_mem_write,
    - .write_atomic = native_apic_mem_write_atomic,
    .icr_read = xapic_icr_read,
    .icr_write = xapic_icr_write,
    .wait_icr_idle = xapic_wait_icr_idle,
    diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
    index 46e6124..a850bc6 100644
    --- a/arch/x86/kernel/apic_64.c
    +++ b/arch/x86/kernel/apic_64.c
    @@ -167,7 +167,6 @@ u64 xapic_icr_read(void)
    static struct apic_ops xapic_ops = {
    .read = native_apic_mem_read,
    .write = native_apic_mem_write,
    - .write_atomic = native_apic_mem_write_atomic,
    .icr_read = xapic_icr_read,
    .icr_write = xapic_icr_write,
    .wait_icr_idle = xapic_wait_icr_idle,
    @@ -206,7 +205,6 @@ u64 x2apic_icr_read(void)
    static struct apic_ops x2apic_ops = {
    .read = native_apic_msr_read,
    .write = native_apic_msr_write,
    - .write_atomic = native_apic_msr_write,
    .icr_read = x2apic_icr_read,
    .icr_write = x2apic_icr_write,
    .wait_icr_idle = x2apic_wait_icr_idle,
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  12. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, Jul 18, 2008 at 4:00 PM, Suresh Siddha
    wrote:
    > On Fri, Jul 18, 2008 at 03:51:07PM -0700, Yinghai Lu wrote:
    >> On Fri, Jul 18, 2008 at 3:49 PM, Suresh Siddha
    >> wrote:
    >> > Thanks to Maciej who posted this fix. It was on my todo list for
    >> > sometime now!

    >>
    >> do we rebase tip/x86/x2apic or rework this patch?

    >
    > Ingo just did the merge. And I posted a missing piece. So is this enough?


    maciej, patch will go first, and x2apic will goes later, so bisect on
    x2apic will be broken.

    YH
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  13. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, Jul 18, 2008 at 03:51:07PM -0700, Yinghai Lu wrote:
    > On Fri, Jul 18, 2008 at 3:49 PM, Suresh Siddha
    > wrote:
    > > Thanks to Maciej who posted this fix. It was on my todo list for
    > > sometime now!

    >
    > do we rebase tip/x86/x2apic or rework this patch?


    Ingo just did the merge. And I posted a missing piece. So is this enough?

    I will do more testing of the merge.

    thanks,
    suresh
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  14. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, Jul 18, 2008 at 04:04:29PM -0700, Yinghai Lu wrote:
    > On Fri, Jul 18, 2008 at 4:00 PM, Suresh Siddha
    > wrote:
    > > On Fri, Jul 18, 2008 at 03:51:07PM -0700, Yinghai Lu wrote:
    > >> On Fri, Jul 18, 2008 at 3:49 PM, Suresh Siddha
    > >> wrote:
    > >> > Thanks to Maciej who posted this fix. It was on my todo list for
    > >> > sometime now!
    > >>
    > >> do we rebase tip/x86/x2apic or rework this patch?

    > >
    > > Ingo just did the merge. And I posted a missing piece. So is this enough?

    >
    > maciej, patch will go first, and x2apic will goes later, so bisect on
    > x2apic will be broken.


    hm, ok. Ingo? should I send the rebased 30 or so patches. or we can move this
    patch later.

    thanks,
    suresh
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  15. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives

    On Fri, 2008-07-18 at 15:49 -0700, Suresh Siddha wrote:

    > > Thank you for cleaning this up Yinghai, but this really begs the
    > > question - is having write_atomic REALLY worthwhile?

    >
    > And this thread is about, Maciej's cleanup patch which removed
    > write_atomic completely
    >
    > Thanks to Maciej who posted this fix. It was on my todo list for
    > sometime now!


    Awesome! I just felt the need to use 'flaming crap' in a sentence
    today, and broken APICs seemed like an easy target. Glad to know it's
    gone.

    Zach

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  16. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives


    * Zachary Amsden wrote:

    > On Fri, 2008-07-18 at 15:49 -0700, Suresh Siddha wrote:
    >
    > > > Thank you for cleaning this up Yinghai, but this really begs the
    > > > question - is having write_atomic REALLY worthwhile?

    > >
    > > And this thread is about, Maciej's cleanup patch which removed
    > > write_atomic completely
    > >
    > > Thanks to Maciej who posted this fix. It was on my todo list for
    > > sometime now!

    >
    > Awesome! I just felt the need to use 'flaming crap' in a sentence
    > today, and broken APICs seemed like an easy target. Glad to know it's
    > gone.


    it's gone, but without breaking or limiting old hardware: it's done by
    moving the code into a quirk. And that's the general direction which we
    want to take in such cases - move ugly non-standard stuff into
    low-maintenance-overhead quirks.

    Ingo
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  17. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives


    * Suresh Siddha wrote:

    > On Fri, Jul 18, 2008 at 02:03:48PM -0700, Ingo Molnar wrote:
    > >
    > > * Yinghai Lu wrote:
    > >
    > > > > git merge tip/x86/x2apic
    > > > CONFLICT (content): Merge conflict in arch/x86/kernel/Makefile
    > > > CONFLICT (content): Merge conflict in arch/x86/kernel/paravirt.c
    > > > CONFLICT (content): Merge conflict in arch/x86/kernel/smpboot.c
    > > > CONFLICT (content): Merge conflict in arch/x86/kernel/vmi_32.c
    > > > CONFLICT (content): Merge conflict in arch/x86/xen/enlighten.c
    > > > CONFLICT (content): Merge conflict in include/asm-x86/apic.h
    > > > CONFLICT (content): Merge conflict in include/asm-x86/paravirt.h

    > >
    > > that's due to the changes in tip/x86/apic and in tip/x86/uv.
    > >
    > > ok, i've just merged x86/apic into x86/x2apic and x86/uv as well, and
    > > pushed out the result.
    > >
    > > Note: it's a first raw merge and completely untested. It will now merge
    > > cleanly into tip/master. There are probably a few details missing.

    >
    > Ingo, thanks for doing this. While I was testing my merge changes, you
    > posted yours... anyhow we need this piece, which is missing from your
    > merge.


    thanks, applied and pushed out. Could you check whether the latest
    tip/x86/x2apic code, when git-merge-ed into tip/master, is sane on your
    box(en)?

    Ingo
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  18. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives


    * Ingo Molnar wrote:

    > > > maciej, patch will go first, and x2apic will goes later, so bisect
    > > > on x2apic will be broken.

    > >
    > > hm, ok. Ingo? should I send the rebased 30 or so patches. or we can
    > > move this patch later.

    >
    > hm, yes, please send the rebased patches - as this stuff has some
    > risks so bisectability is important.


    hm, actually - the order is correct so no need to rebase any of this.

    We've got two topics: tip/x86/apic and tip/x86/x2apic.

    both tip/x86/x2apic and tip/x86/apic were OK standalone. I merged them
    together in this commit:

    commit 453c1404c5273a30d715e5a83372a78cff70b6d9
    Merge: a208f37... 35b6805...
    Author: Ingo Molnar
    Date: Fri Jul 18 23:00:05 2008 +0200

    Merge branch 'x86/apic' into x86/x2apic

    Conflicts:

    arch/x86/kernel/paravirt.c
    arch/x86/kernel/smpboot.c
    arch/x86/kernel/vmi_32.c
    arch/x86/lguest/boot.c
    arch/x86/xen/enlighten.c
    include/asm-x86/apic.h
    include/asm-x86/paravirt.h

    Signed-off-by: Ingo Molnar

    and that didnt work straight away, so i applied your fixups - but that's
    the next commit. So there's only a single commit that is not bisectable
    and that's OK.

    so unless there's some other breakage i missed, this should be fine and
    no need to resend/rebase anything.

    Ingo
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  19. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives


    * Suresh Siddha wrote:

    > On Fri, Jul 18, 2008 at 04:04:29PM -0700, Yinghai Lu wrote:
    > > On Fri, Jul 18, 2008 at 4:00 PM, Suresh Siddha
    > > wrote:
    > > > On Fri, Jul 18, 2008 at 03:51:07PM -0700, Yinghai Lu wrote:
    > > >> On Fri, Jul 18, 2008 at 3:49 PM, Suresh Siddha
    > > >> wrote:
    > > >> > Thanks to Maciej who posted this fix. It was on my todo list for
    > > >> > sometime now!
    > > >>
    > > >> do we rebase tip/x86/x2apic or rework this patch?
    > > >
    > > > Ingo just did the merge. And I posted a missing piece. So is this enough?

    > >
    > > maciej, patch will go first, and x2apic will goes later, so bisect on
    > > x2apic will be broken.

    >
    > hm, ok. Ingo? should I send the rebased 30 or so patches. or we can
    > move this patch later.


    hm, yes, please send the rebased patches - as this stuff has some risks
    so bisectability is important.

    Ingo
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  20. Re: [PATCH] x86: APIC: Remove apic_write_around(); use alternatives


    i've merged tip/x86/x2apic into tip/master, and it seems to be working
    fine. One UP build fix was needed for Xen, see below.

    Ingo

    -------------------------->
    commit caf43bf7c6a55e89b6df5179df434d67e24aa32e
    Author: Ingo Molnar
    Date: Sun Jul 20 14:06:50 2008 +0200

    x86, xen: fix apic_ops build on UP

    fix:

    arch/x86/xen/enlighten.c:615: error: variable ‘xen_basic_apic_ops’ has initializer but incomplete type
    arch/x86/xen/enlighten.c:616: error: unknown field ‘read’ specified in initializer
    [...]

    Signed-off-by: Ingo Molnar
    ---
    arch/x86/xen/enlighten.c | 1 +
    1 files changed, 1 insertions(+), 0 deletions(-)

    diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
    index 008b7b6..e4d1459 100644
    --- a/arch/x86/xen/enlighten.c
    +++ b/arch/x86/xen/enlighten.c
    @@ -35,6 +35,7 @@
    #include

    #include
    +#include
    #include
    #include
    #include
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