From: Suresh Siddha Subject: x64, x2apic/intr-remap: add x2apic support, including enabling interrupt-remapping References: fate #303948 and fate #303984 Patch-Mainline: queued for .28 Commit-ID: 6e1cb38a2aef7680975e71f23de187859ee8b158 Signed-off-by: Thomas Renninger x2apic support. Interrupt-remapping must be enabled before enabling x2apic, this is needed to ensure that IO interrupts continue to work properly after the cpu mode is changed to x2apic(which uses 32bit extended physical/cluster apic id). On systems where apicid's are > 255, BIOS can handover the control to OS in x2apic mode. Or if the OS handover was in legacy xapic mode, check if it is capable of x2apic mode. And if we succeed in enabling Interrupt-remapping, then we can enable x2apic mode in the CPU. Signed-off-by: Suresh Siddha Cc: akpm@linux-foundation.org Cc: arjan@linux.intel.com Cc: andi@firstfloor.org Cc: ebiederm@xmission.com Cc: jbarnes@virtuousgeek.org Cc: steiner@sgi.com Signed-off-by: Ingo Molnar --- Documentation/kernel-parameters.txt | 2 arch/x86/kernel/acpi/boot.c | 2 arch/x86/kernel/apic_64.c | 154 +++++++++++++++++++++++++++++++++++- arch/x86/kernel/cpu/common_64.c | 2 arch/x86/kernel/mpparse.c | 2 arch/x86/kernel/setup.c | 2 arch/x86/kernel/smpboot.c | 5 + include/asm-x86/apic.h | 14 +-- 8 files changed, 172 insertions(+), 11 deletions(-) --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1428,6 +1428,8 @@ and is between 256 and 4096 characters. nolapic_timer [X86-32,APIC] Do not use the local APIC timer. + nox2apic [X86-64,APIC] Do not enable x2APIC mode. + noltlbs [PPC] Do not use large page/tlb entries for kernel lowmem mapping on PPC40x. --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -1351,7 +1351,9 @@ static void __init acpi_process_madt(voi acpi_ioapic = 1; smp_found_config = 1; +#ifdef CONFIG_X86_32 setup_apic_routing(); +#endif } } if (error == -EINVAL) { --- a/arch/x86/kernel/apic_64.c +++ b/arch/x86/kernel/apic_64.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #include @@ -39,6 +40,7 @@ #include #include #include +#include #include #include @@ -46,8 +48,12 @@ static int disable_apic_timer __cpuinitdata; static int apic_calibrate_pmtmr __initdata; int disable_apic; +int disable_x2apic; int x2apic; +/* x2apic enabled before OS handover */ +int x2apic_preenabled; + /* Local APIC timer works in C2 */ int local_apic_timer_c2_ok; EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok); @@ -925,6 +931,125 @@ void __cpuinit end_local_APIC_setup(void apic_pm_activate(); } +void check_x2apic(void) +{ + int msr, msr2; + + rdmsr(MSR_IA32_APICBASE, msr, msr2); + + if (msr & X2APIC_ENABLE) { + printk("x2apic enabled by BIOS, switching to x2apic ops\n"); + x2apic_preenabled = x2apic = 1; + apic_ops = &x2apic_ops; + } +} + +void enable_x2apic(void) +{ + int msr, msr2; + + rdmsr(MSR_IA32_APICBASE, msr, msr2); + if (!(msr & X2APIC_ENABLE)) { + printk("Enabling x2apic\n"); + wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0); + } +} + +void enable_IR_x2apic(void) +{ +#ifdef CONFIG_INTR_REMAP + int ret; + unsigned long flags; + + if (!cpu_has_x2apic) + return; + + if (!x2apic_preenabled && disable_x2apic) { + printk(KERN_INFO + "Skipped enabling x2apic and Interrupt-remapping " + "because of nox2apic\n"); + return; + } + + if (x2apic_preenabled && disable_x2apic) + panic("Bios already enabled x2apic, can't enforce nox2apic"); + + if (!x2apic_preenabled && skip_ioapic_setup) { + printk(KERN_INFO + "Skipped enabling x2apic and Interrupt-remapping " + "because of skipping io-apic setup\n"); + return; + } + + ret = dmar_table_init(); + if (ret) { + printk(KERN_INFO + "dmar_table_init() failed with %d:\n", ret); + + if (x2apic_preenabled) + panic("x2apic enabled by bios. But IR enabling failed"); + else + printk(KERN_INFO + "Not enabling x2apic,Intr-remapping\n"); + return; + } + + local_irq_save(flags); + mask_8259A(); + save_mask_IO_APIC_setup(); + + ret = enable_intr_remapping(1); + + if (ret && x2apic_preenabled) { + local_irq_restore(flags); + panic("x2apic enabled by bios. But IR enabling failed"); + } + + if (ret) + goto end; + + if (!x2apic) { + x2apic = 1; + apic_ops = &x2apic_ops; + enable_x2apic(); + } +end: + if (ret) + /* + * IR enabling failed + */ + restore_IO_APIC_setup(); + else + reinit_intr_remapped_IO_APIC(x2apic_preenabled); + + unmask_8259A(); + local_irq_restore(flags); + + if (!ret) { + if (!x2apic_preenabled) + printk(KERN_INFO + "Enabled x2apic and interrupt-remapping\n"); + else + printk(KERN_INFO + "Enabled Interrupt-remapping\n"); + } else + printk(KERN_ERR + "Failed to enable Interrupt-remapping and x2apic\n"); +#else + if (!cpu_has_x2apic) + return; + + if (x2apic_preenabled) + panic("x2apic enabled prior OS handover," + " enable CONFIG_INTR_REMAP"); + + printk(KERN_INFO "Enable CONFIG_INTR_REMAP for enabling intr-remapping " + " and x2apic\n"); +#endif + + return; +} + /* * Detect and enable local APICs on non-SMP boards. * Original code written by Keir Fraser. @@ -972,6 +1097,11 @@ void __init early_init_lapic_mapping(voi */ void __init init_apic_mappings(void) { + if (x2apic) { + boot_cpu_physical_apicid = GET_APIC_ID(read_apic_id()); + return; + } + /* * If no local APIC can be found then set up a fake all * zeroes page to simulate the local APIC and another @@ -1010,6 +1140,9 @@ int __init APIC_init_uniprocessor(void) return -1; } + enable_IR_x2apic(); + setup_apic_routing(); + verify_local_APIC(); connect_bsp_APIC(); @@ -1263,10 +1396,14 @@ static int lapic_resume(struct sys_devic maxlvt = lapic_get_maxlvt(); local_irq_save(flags); - rdmsr(MSR_IA32_APICBASE, l, h); - l &= ~MSR_IA32_APICBASE_BASE; - l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr; - wrmsr(MSR_IA32_APICBASE, l, h); + if (!x2apic) { + rdmsr(MSR_IA32_APICBASE, l, h); + l &= ~MSR_IA32_APICBASE_BASE; + l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr; + wrmsr(MSR_IA32_APICBASE, l, h); + } else + enable_x2apic(); + apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED); apic_write(APIC_ID, apic_pm_state.apic_id); apic_write(APIC_DFR, apic_pm_state.apic_dfr); @@ -1406,6 +1543,15 @@ __cpuinit int apic_is_clustered_box(void return (clusters > 2); } +static __init int setup_nox2apic(char *str) +{ + disable_x2apic = 1; + clear_cpu_cap(&boot_cpu_data, X86_FEATURE_X2APIC); + return 0; +} +early_param("nox2apic", setup_nox2apic); + + /* * APIC command line parameters */ --- a/arch/x86/kernel/cpu/common_64.c +++ b/arch/x86/kernel/cpu/common_64.c @@ -636,6 +636,8 @@ void __cpuinit cpu_init(void) barrier(); check_efer(); + if (cpu != 0 && x2apic) + enable_x2apic(); /* * set up and load the per-CPU TSS --- a/arch/x86/kernel/mpparse.c +++ b/arch/x86/kernel/mpparse.c @@ -397,7 +397,9 @@ static int __init smp_read_mpc(struct mp generic_bigsmp_probe(); #endif +#ifdef CONFIG_X86_32 setup_apic_routing(); +#endif if (!num_processors) printk(KERN_ERR "MPTABLE: no processors registered!\n"); return num_processors; --- a/arch/x86/kernel/setup.c +++ b/arch/x86/kernel/setup.c @@ -769,6 +769,8 @@ void __init setup_arch(char **cmdline_p) #else num_physpages = max_pfn; + if (cpu_has_x2apic) + check_x2apic(); /* How many end-of-memory variables you have, grandma! */ /* need this before calling reserve_initrd */ --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1169,6 +1169,11 @@ void __init native_smp_prepare_cpus(unsi current_thread_info()->cpu = 0; /* needed? */ set_cpu_sibling_map(0); +#ifdef CONFIG_X86_64 + enable_IR_x2apic(); + setup_apic_routing(); +#endif + if (smp_sanity_check(max_cpus) < 0) { printk(KERN_INFO "SMP disabled\n"); disable_smp(); --- a/include/asm-x86/apic.h +++ b/include/asm-x86/apic.h @@ -93,12 +93,13 @@ static inline u32 native_apic_msr_read(u return low; } -#ifdef CONFIG_X86_32 -extern void apic_wait_icr_idle(void); -extern u32 safe_apic_wait_icr_idle(void); -extern void apic_icr_write(u32 low, u32 id); -#else -extern void x2apic_icr_write(u32 low, u32 id); +#ifndef CONFIG_X86_32 + extern int x2apic, x2apic_preenabled; + extern void check_x2apic(void); + extern void enable_x2apic(void); + extern void enable_IR_x2apic(void); + extern void x2apic_icr_write(u32 low, u32 id); +#endif struct apic_ops { u32 (*read)(u32 reg); @@ -119,7 +120,6 @@ extern struct apic_ops *apic_ops; #define apic_icr_write (apic_ops->icr_write) #define apic_wait_icr_idle (apic_ops->wait_icr_idle) #define safe_apic_wait_icr_idle (apic_ops->safe_wait_icr_idle) -#endif extern int get_physical_broadcast(void);