From 5a7ae78fd478624df3059cb6f55056b85d074acc Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 19 Oct 2010 10:46:28 -0700 Subject: x86: Allow platforms to force enable apic Some embedded x86 platforms don't setup the APIC in the BIOS/bootloader and would be forced to add "lapic" on the kernel command line. That's a bit akward. Split out the force enable code from detect_init_APIC() and allow platform code to call it from the platform setup. That avoids the command line parameter and possible replication of the MSR dance in the force enable code. Signed-off-by: Thomas Gleixner LKML-Reference: <1287510389-8388-1-git-send-email-dirk.brandewie@gmail.com> Signed-off-by: Dirk Brandewie --- arch/x86/kernel/apic/apic.c | 87 ++++++++++++++++++++++++++++----------------- 1 file changed, 54 insertions(+), 33 deletions(-) (limited to 'arch/x86/kernel/apic/apic.c') diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 850657d1b0ed..463839645f9b 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1531,13 +1531,60 @@ static int __init detect_init_APIC(void) return 0; } #else + +static int apic_verify(void) +{ + u32 features, h, l; + + /* + * The APIC feature bit should now be enabled + * in `cpuid' + */ + features = cpuid_edx(1); + if (!(features & (1 << X86_FEATURE_APIC))) { + pr_warning("Could not enable APIC!\n"); + return -1; + } + set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC); + mp_lapic_addr = APIC_DEFAULT_PHYS_BASE; + + /* The BIOS may have set up the APIC at some other address */ + rdmsr(MSR_IA32_APICBASE, l, h); + if (l & MSR_IA32_APICBASE_ENABLE) + mp_lapic_addr = l & MSR_IA32_APICBASE_BASE; + + pr_info("Found and enabled local APIC!\n"); + return 0; +} + +int apic_force_enable(void) +{ + u32 h, l; + + if (disable_apic) + return -1; + + /* + * Some BIOSes disable the local APIC in the APIC_BASE + * MSR. This can only be done in software for Intel P6 or later + * and AMD K7 (Model > 1) or later. + */ + rdmsr(MSR_IA32_APICBASE, l, h); + if (!(l & MSR_IA32_APICBASE_ENABLE)) { + pr_info("Local APIC disabled by BIOS -- reenabling.\n"); + l &= ~MSR_IA32_APICBASE_BASE; + l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE; + wrmsr(MSR_IA32_APICBASE, l, h); + enabled_via_apicbase = 1; + } + return apic_verify(); +} + /* * Detect and initialize APIC */ static int __init detect_init_APIC(void) { - u32 h, l, features; - /* Disabled by kernel option? */ if (disable_apic) return -1; @@ -1567,38 +1614,12 @@ static int __init detect_init_APIC(void) "you can enable it with \"lapic\"\n"); return -1; } - /* - * Some BIOSes disable the local APIC in the APIC_BASE - * MSR. This can only be done in software for Intel P6 or later - * and AMD K7 (Model > 1) or later. - */ - rdmsr(MSR_IA32_APICBASE, l, h); - if (!(l & MSR_IA32_APICBASE_ENABLE)) { - pr_info("Local APIC disabled by BIOS -- reenabling.\n"); - l &= ~MSR_IA32_APICBASE_BASE; - l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE; - wrmsr(MSR_IA32_APICBASE, l, h); - enabled_via_apicbase = 1; - } - } - /* - * The APIC feature bit should now be enabled - * in `cpuid' - */ - features = cpuid_edx(1); - if (!(features & (1 << X86_FEATURE_APIC))) { - pr_warning("Could not enable APIC!\n"); - return -1; + if (apic_force_enable()) + return -1; + } else { + if (apic_verify()) + return -1; } - set_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC); - mp_lapic_addr = APIC_DEFAULT_PHYS_BASE; - - /* The BIOS may have set up the APIC at some other address */ - rdmsr(MSR_IA32_APICBASE, l, h); - if (l & MSR_IA32_APICBASE_ENABLE) - mp_lapic_addr = l & MSR_IA32_APICBASE_BASE; - - pr_info("Found and enabled local APIC!\n"); apic_pm_activate(); -- cgit v1.2.2 From c0104d38a740b25662c592c71f6907676510289c Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 7 Dec 2010 00:55:17 -0800 Subject: x86, apic: Unify identical register_lapic_address() functions They are the same, move the common function to apic.c to allow further cleanups. Signed-off-by: Yinghai Lu Cc: Suresh Siddha Cc: "Eric W. Biederman" Cc: Len Brown LKML-Reference: <4CFDF675.4060305@kernel.org> Signed-off-by: Thomas Gleixner --- arch/x86/kernel/apic/apic.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'arch/x86/kernel/apic/apic.c') diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index c48a64510844..c02bf135de9d 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1702,6 +1702,18 @@ void __init init_apic_mappings(void) } } +void __init register_lapic_address(unsigned long address) +{ + mp_lapic_addr = address; + + set_fixmap_nocache(FIX_APIC_BASE, address); + if (boot_cpu_physical_apicid == -1U) { + boot_cpu_physical_apicid = read_apic_id(); + apic_version[boot_cpu_physical_apicid] = + GET_APIC_VERSION(apic_read(APIC_LVR)); + } +} + /* * This initializes the IO-APIC and APIC hardware if this is * a UP kernel. -- cgit v1.2.2 From f1157141636848f52c5f74040bed0ba355cf59b7 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 7 Dec 2010 00:55:29 -0800 Subject: x86, apic: Remove early_init_lapic_mapping() It is almost the same as smp_register_lapic_addr(). We just need to let smp_read_mpc() call smp_register_lapic_addr() when early==1. Add the apic_printk to smp_register_lapic_address() Signed-off-by: Yinghai Lu Cc: Suresh Siddha Cc: "Eric W. Biederman" LKML-Reference: <4CFDF681.3030509@kernel.org> Signed-off-by: Thomas Gleixner --- arch/x86/kernel/apic/apic.c | 24 ++---------------------- 1 file changed, 2 insertions(+), 22 deletions(-) (limited to 'arch/x86/kernel/apic/apic.c') diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index c02bf135de9d..f507f311d44d 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1630,28 +1630,6 @@ no_apic: } #endif -#ifdef CONFIG_X86_64 -void __init early_init_lapic_mapping(void) -{ - /* - * If no local APIC can be found then go out - * : it means there is no mpatable and MADT - */ - if (!smp_found_config) - return; - - set_fixmap_nocache(FIX_APIC_BASE, mp_lapic_addr); - apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n", - APIC_BASE, mp_lapic_addr); - - /* - * Fetch the APIC ID of the BSP in case we have a - * default configuration (or the MP table is broken). - */ - boot_cpu_physical_apicid = read_apic_id(); -} -#endif - /** * init_apic_mappings - initialize APIC mappings */ @@ -1707,6 +1685,8 @@ void __init register_lapic_address(unsigned long address) mp_lapic_addr = address; set_fixmap_nocache(FIX_APIC_BASE, address); + apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n", + APIC_BASE, mp_lapic_addr); if (boot_cpu_physical_apicid == -1U) { boot_cpu_physical_apicid = read_apic_id(); apic_version[boot_cpu_physical_apicid] = -- cgit v1.2.2 From 326a2e6bae250b1172c0ae80f3b259d79e9cb56c Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 7 Dec 2010 00:55:38 -0800 Subject: x86, apic: Use register_lapic_address() in init_apic_mapping() Remove the printk as well, we don't want to print when nothing changed. We print in register_lapic_address() already. Signed-off-by: Yinghai Lu Cc: Suresh Siddha Cc: "Eric W. Biederman" LKML-Reference: <4CFDF68A.7020902@kernel.org> Signed-off-by: Thomas Gleixner --- arch/x86/kernel/apic/apic.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'arch/x86/kernel/apic/apic.c') diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index f507f311d44d..9303364e2009 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1655,10 +1655,7 @@ void __init init_apic_mappings(void) * acpi_register_lapic_address() */ if (!acpi_lapic && !smp_found_config) - set_fixmap_nocache(FIX_APIC_BASE, apic_phys); - - apic_printk(APIC_VERBOSE, "mapped APIC to %08lx (%08lx)\n", - APIC_BASE, apic_phys); + register_lapic_address(apic_phys); } /* -- cgit v1.2.2 From 0450193bffed6e4b6160c4a5ccb0df158eba7d2a Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 7 Dec 2010 00:55:56 -0800 Subject: x86, x2apic: Don't map lapic addr for preenabled x2apic systems If x2apic is preenabled and used by the kernel, we don't need to map the lapic address. That mapping will never be used. So just skip that in register_lapic_address() Signed-off-by: Yinghai Lu Cc: Suresh Siddha Cc: "Eric W. Biederman" LKML-Reference: <4CFDF69C.9070501@kernel.org> Signed-off-by: Thomas Gleixner --- arch/x86/kernel/apic/apic.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'arch/x86/kernel/apic/apic.c') diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 9303364e2009..89339360b3d8 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1681,9 +1681,11 @@ void __init register_lapic_address(unsigned long address) { mp_lapic_addr = address; - set_fixmap_nocache(FIX_APIC_BASE, address); - apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n", - APIC_BASE, mp_lapic_addr); + if (!x2apic_mode) { + set_fixmap_nocache(FIX_APIC_BASE, address); + apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n", + APIC_BASE, mp_lapic_addr); + } if (boot_cpu_physical_apicid == -1U) { boot_cpu_physical_apicid = read_apic_id(); apic_version[boot_cpu_physical_apicid] = -- cgit v1.2.2 From 0aa002fe602939370e9476e5ec32b562000a0425 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 9 Dec 2010 11:47:21 +0100 Subject: x86: apic: Cleanup and simplify setup_local_APIC() setup_local_APIC() is used to setup local APIC early during CPU initialization and already assumes that preemption is disabled on entry. However, The function unnecessarily disables and enables preemption and uses smp_processor_id() multiple times in and out of the nested preemption disabled section. This gives the wrong impression that the function might be able to handle being called with preemption enabled and/or migrated to another processor in the middle. Make it clear that the function is always called with preemption disabled, drop the confusing preemption disable block and call smp_processor_id() once at the beginning of the function. Signed-off-by: Tejun Heo Acked-by: Cyrill Gorcunov Reviewed-by: Pekka Enberg Cc: Yinghai Lu Cc: brgerst@gmail.com LKML-Reference: <4D00B3B9.7060702@kernel.org> Signed-off-by: Thomas Gleixner --- arch/x86/kernel/apic/apic.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) (limited to 'arch/x86/kernel/apic/apic.c') diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 89339360b3d8..c0f6426cd337 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1195,12 +1195,15 @@ static void __cpuinit lapic_setup_esr(void) oldvalue, value); } - /** * setup_local_APIC - setup the local APIC + * + * Used to setup local APIC while initializing BSP or bringin up APs. + * Always called with preemption disabled. */ void __cpuinit setup_local_APIC(void) { + int cpu = smp_processor_id(); unsigned int value, queued; int i, j, acked = 0; unsigned long long tsc = 0, ntsc; @@ -1225,8 +1228,6 @@ void __cpuinit setup_local_APIC(void) #endif perf_events_lapic_init(); - preempt_disable(); - /* * Double-check whether this APIC is really registered. * This is meaningless in clustered apic mode, so we skip it. @@ -1342,21 +1343,19 @@ void __cpuinit setup_local_APIC(void) * TODO: set up through-local-APIC from through-I/O-APIC? --macro */ value = apic_read(APIC_LVT0) & APIC_LVT_MASKED; - if (!smp_processor_id() && (pic_mode || !value)) { + if (!cpu && (pic_mode || !value)) { value = APIC_DM_EXTINT; - apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", - smp_processor_id()); + apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", cpu); } else { value = APIC_DM_EXTINT | APIC_LVT_MASKED; - apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", - smp_processor_id()); + apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", cpu); } apic_write(APIC_LVT0, value); /* * only the BP should see the LINT1 NMI signal, obviously. */ - if (!smp_processor_id()) + if (!cpu) value = APIC_DM_NMI; else value = APIC_DM_NMI | APIC_LVT_MASKED; @@ -1364,11 +1363,9 @@ void __cpuinit setup_local_APIC(void) value |= APIC_LVT_LEVEL_TRIGGER; apic_write(APIC_LVT1, value); - preempt_enable(); - #ifdef CONFIG_X86_MCE_INTEL /* Recheck CMCI information after local APIC is up on CPU #0 */ - if (smp_processor_id() == 0) + if (!cpu) cmci_recheck(); #endif } -- cgit v1.2.2