From f2b36db692b7ff6972320ad9839ae656a3b0ee3e Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Sun, 30 Oct 2005 14:59:41 -0800 Subject: [PATCH] i386: move apic init in init_IRQs All kinds of ugliness exists because we don't initialize the apics during init_IRQs. - We calibrate jiffies in non apic mode even when we are using apics. - We have to have special code to initialize the apics when non-smp. - The legacy i8259 must exist and be setup correctly, even when we won't use it past initialization. - The kexec on panic code must restore the state of the io_apics. - init/main.c needs a special case for !smp smp_init on x86 In addition to pure code movement I needed a couple of non-obvious changes: - Move setup_boot_APIC_clock into APIC_late_time_init for simplicity. - Use cpu_khz to generate a better approximation of loops_per_jiffies so I can verify the timer interrupt is working. - Call setup_apic_nmi_watchdog again after cpu_khz is initialized on the boot cpu. Signed-off-by: Eric W. Biederman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/apic.c | 81 ++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 64 insertions(+), 17 deletions(-) (limited to 'arch/i386/kernel/apic.c') diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c index 5546ddebec33..8d81b7bf7ad2 100644 --- a/arch/i386/kernel/apic.c +++ b/arch/i386/kernel/apic.c @@ -803,6 +803,7 @@ no_apic: void __init init_apic_mappings(void) { + unsigned int orig_apicid; unsigned long apic_phys; /* @@ -824,8 +825,11 @@ void __init init_apic_mappings(void) * Fetch the APIC ID of the BSP in case we have a * default configuration (or the MP table is broken). */ - if (boot_cpu_physical_apicid == -1U) - boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID)); + orig_apicid = boot_cpu_physical_apicid; + boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID)); + if ((orig_apicid != -1U) && (orig_apicid != boot_cpu_physical_apicid)) + printk(KERN_WARNING "Boot APIC ID in local APIC unexpected (%d vs %d)", + orig_apicid, boot_cpu_physical_apicid); #ifdef CONFIG_X86_IO_APIC { @@ -1046,9 +1050,11 @@ static unsigned int calibration_result; void __init setup_boot_APIC_clock(void) { + unsigned long flags; apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"); using_apic_timer = 1; + local_irq_save(flags); local_irq_disable(); calibration_result = calibrate_APIC_clock(); @@ -1057,7 +1063,7 @@ void __init setup_boot_APIC_clock(void) */ setup_APIC_timer(calibration_result); - local_irq_enable(); + local_irq_restore(flags); } void __devinit setup_secondary_APIC_clock(void) @@ -1254,40 +1260,81 @@ fastcall void smp_error_interrupt(struct pt_regs *regs) } /* - * This initializes the IO-APIC and APIC hardware if this is - * a UP kernel. + * This initializes the IO-APIC and APIC hardware. */ -int __init APIC_init_uniprocessor (void) +int __init APIC_init(void) { - if (enable_local_apic < 0) - clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability); + if (enable_local_apic < 0) { + printk(KERN_INFO "APIC disabled\n"); + return -1; + } - if (!smp_found_config && !cpu_has_apic) + /* See if we have a SMP configuration or have forced enabled + * the local apic. + */ + if (!smp_found_config && !acpi_lapic && !cpu_has_apic) { + enable_local_apic = -1; return -1; + } /* - * Complain if the BIOS pretends there is one. + * Complain if the BIOS pretends there is an apic. + * Then get out because we don't have an a local apic. */ if (!cpu_has_apic && APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) { printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n", boot_cpu_physical_apicid); + printk(KERN_ERR "... forcing use of dummy APIC emulation. (tell your hw vendor)\n"); + enable_local_apic = -1; return -1; } verify_local_APIC(); + /* + * Should not be necessary because the MP table should list the boot + * CPU too, but we do it for the sake of robustness anyway. + * Makes no sense to do this check in clustered apic mode, so skip it + */ + if (!check_phys_apicid_present(boot_cpu_physical_apicid)) { + printk("weird, boot CPU (#%d) not listed by the BIOS.\n", + boot_cpu_physical_apicid); + physid_set(hard_smp_processor_id(), phys_cpu_present_map); + } + + /* + * Switch from PIC to APIC mode. + */ connect_bsp_APIC(); + setup_local_APIC(); - phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid); +#ifdef CONFIG_X86_IO_APIC + /* + * Now start the IO-APICs + */ + if (smp_found_config && !skip_ioapic_setup && nr_ioapics) + setup_IO_APIC(); +#endif + return 0; +} - setup_local_APIC(); +void __init APIC_late_time_init(void) +{ + /* Improve our loops per jiffy estimate */ + loops_per_jiffy = ((1000 + HZ - 1)/HZ)*cpu_khz; + boot_cpu_data.loops_per_jiffy = loops_per_jiffy; + cpu_data[0].loops_per_jiffy = loops_per_jiffy; + + /* setup_apic_nmi_watchdog doesn't work properly before cpu_khz is + * initialized. So redo it here to ensure the boot cpu is setup + * properly. + */ + if (nmi_watchdog == NMI_LOCAL_APIC) + setup_apic_nmi_watchdog(); #ifdef CONFIG_X86_IO_APIC - if (smp_found_config) - if (!skip_ioapic_setup && nr_ioapics) - setup_IO_APIC(); + if (smp_found_config && !skip_ioapic_setup && nr_ioapics) + IO_APIC_late_time_init(); #endif setup_boot_APIC_clock(); - - return 0; } -- cgit v1.2.3