diff options
Diffstat (limited to 'arch/x86_64/kernel/genapic_flat.c')
| -rw-r--r-- | arch/x86_64/kernel/genapic_flat.c | 142 |
1 files changed, 59 insertions, 83 deletions
diff --git a/arch/x86_64/kernel/genapic_flat.c b/arch/x86_64/kernel/genapic_flat.c index 28284696508..adc96282a9e 100644 --- a/arch/x86_64/kernel/genapic_flat.c +++ b/arch/x86_64/kernel/genapic_flat.c @@ -2,13 +2,11 @@ * Copyright 2004 James Cleverdon, IBM. * Subject to the GNU Public License, v.2 * - * Flat APIC subarch code. Maximum 8 CPUs, logical delivery. + * Flat APIC subarch code. * * Hacked for x86-64 by James Cleverdon from i386 architecture code by * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and * James Cleverdon. - * Ashok Raj <ashok.raj@intel.com> - * Removed IPI broadcast shortcut to support CPU hotplug */ #include <linux/config.h> #include <linux/threads.h> @@ -20,47 +18,6 @@ #include <asm/smp.h> #include <asm/ipi.h> -/* - * The following permit choosing broadcast IPI shortcut v.s sending IPI only - * to online cpus via the send_IPI_mask varient. - * The mask version is my preferred option, since it eliminates a lot of - * other extra code that would need to be written to cleanup intrs sent - * to a CPU while offline. - * - * Sending broadcast introduces lots of trouble in CPU hotplug situations. - * These IPI's are delivered to cpu's irrespective of their offline status - * and could pickup stale intr data when these CPUS are turned online. - * - * Not using broadcast is a cleaner approach IMO, but Andi Kleen disagrees with - * the idea of not using broadcast IPI's anymore. Hence the run time check - * is introduced, on his request so we can choose an alternate mechanism. - * - * Initial wacky performance tests that collect cycle counts show - * no increase in using mask v.s broadcast version. In fact they seem - * identical in terms of cycle counts. - * - * if we need to use broadcast, we need to do the following. - * - * cli; - * hold call_lock; - * clear any pending IPI, just ack and clear all pending intr - * set cpu_online_map; - * release call_lock; - * sti; - * - * The complicated dummy irq processing shown above is not required if - * we didnt sent IPI's to wrong CPU's in the first place. - * - * - Ashok Raj <ashok.raj@intel.com> - */ -#ifdef CONFIG_HOTPLUG_CPU -#define DEFAULT_SEND_IPI (1) -#else -#define DEFAULT_SEND_IPI (0) -#endif - -static int no_broadcast=DEFAULT_SEND_IPI; - static cpumask_t flat_target_cpus(void) { return cpu_online_map; @@ -119,37 +76,15 @@ static void flat_send_IPI_mask(cpumask_t cpumask, int vector) local_irq_restore(flags); } -static inline void __local_flat_send_IPI_allbutself(int vector) -{ - if (no_broadcast) { - cpumask_t mask = cpu_online_map; - int this_cpu = get_cpu(); - - cpu_clear(this_cpu, mask); - flat_send_IPI_mask(mask, vector); - put_cpu(); - } - else - __send_IPI_shortcut(APIC_DEST_ALLBUT, vector, APIC_DEST_LOGICAL); -} - -static inline void __local_flat_send_IPI_all(int vector) -{ - if (no_broadcast) - flat_send_IPI_mask(cpu_online_map, vector); - else - __send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL); -} - static void flat_send_IPI_allbutself(int vector) { if (((num_online_cpus()) - 1) >= 1) - __local_flat_send_IPI_allbutself(vector); + __send_IPI_shortcut(APIC_DEST_ALLBUT, vector,APIC_DEST_LOGICAL); } static void flat_send_IPI_all(int vector) { - __local_flat_send_IPI_all(vector); + __send_IPI_shortcut(APIC_DEST_ALLINC, vector, APIC_DEST_LOGICAL); } static int flat_apic_id_registered(void) @@ -170,16 +105,6 @@ static unsigned int phys_pkg_id(int index_msb) return ((ebx >> 24) & 0xFF) >> index_msb; } -static __init int no_ipi_broadcast(char *str) -{ - get_option(&str, &no_broadcast); - printk ("Using %s mode\n", no_broadcast ? "No IPI Broadcast" : - "IPI Broadcast"); - return 1; -} - -__setup("no_ipi_broadcast", no_ipi_broadcast); - struct genapic apic_flat = { .name = "flat", .int_delivery_mode = dest_LowestPrio, @@ -195,11 +120,62 @@ struct genapic apic_flat = { .phys_pkg_id = phys_pkg_id, }; -static int __init print_ipi_mode(void) +/* + * Physflat mode is used when there are more than 8 CPUs on a AMD system. + * We cannot use logical delivery in this case because the mask + * overflows, so use physical mode. + */ + +static cpumask_t physflat_target_cpus(void) +{ + return cpumask_of_cpu(0); +} + +static void physflat_send_IPI_mask(cpumask_t cpumask, int vector) +{ + send_IPI_mask_sequence(cpumask, vector); +} + +static void physflat_send_IPI_allbutself(int vector) +{ + cpumask_t allbutme = cpu_online_map; + int me = get_cpu(); + cpu_clear(me, allbutme); + physflat_send_IPI_mask(allbutme, vector); + put_cpu(); +} + +static void physflat_send_IPI_all(int vector) { - printk ("Using IPI %s mode\n", no_broadcast ? "No-Shortcut" : - "Shortcut"); - return 0; + physflat_send_IPI_mask(cpu_online_map, vector); } -late_initcall(print_ipi_mode); +static unsigned int physflat_cpu_mask_to_apicid(cpumask_t cpumask) +{ + int cpu; + + /* + * We're using fixed IRQ delivery, can only return one phys APIC ID. + * May as well be the first. + */ + cpu = first_cpu(cpumask); + if ((unsigned)cpu < NR_CPUS) + return x86_cpu_to_apicid[cpu]; + else + return BAD_APICID; +} + +struct genapic apic_physflat = { + .name = "physical flat", + .int_delivery_mode = dest_LowestPrio, + .int_dest_mode = (APIC_DEST_PHYSICAL != 0), + .int_delivery_dest = APIC_DEST_PHYSICAL | APIC_DM_LOWEST, + .target_cpus = physflat_target_cpus, + .apic_id_registered = flat_apic_id_registered, + .init_apic_ldr = flat_init_apic_ldr,/*not needed, but shouldn't hurt*/ + .send_IPI_all = physflat_send_IPI_all, + .send_IPI_allbutself = physflat_send_IPI_allbutself, + .send_IPI_mask = physflat_send_IPI_mask, + .cpu_mask_to_apicid = physflat_cpu_mask_to_apicid, + .phys_pkg_id = phys_pkg_id, +}; |