From: Mike Travis Date: Fri, 19 Oct 2007 18:35:03 +0000 (+0200) Subject: x86: convert cpu_to_apicid to be a per cpu variable X-Git-Tag: v2.6.24-rc1~132^2~6 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=71fff5e6ca1b738ac4742580e4c0ff79d906f6c8;p=linux-2.6 x86: convert cpu_to_apicid to be a per cpu variable This patch converts the x86_cpu_to_apicid array to be a per cpu variable. This saves sizeof(apicid) * NR unused cpus. Access is mostly from startup and CPU HOTPLUG functions. MP_processor_info() is one of the functions that require access to the x86_cpu_to_apicid array before the per_cpu data area is setup. For this case, a pointer to the __initdata array is initialized in setup_arch() and removed in smp_prepare_cpus() after the per_cpu data area is initialized. A second change is included to change the initial array value of ARCH i386 from 0xff to BAD_APICID to be consistent with ARCH x86_64. Signed-off-by: Mike Travis Cc: Andi Kleen Cc: Christoph Lameter Cc: "Siddha, Suresh B" Signed-off-by: Andrew Morton Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index afd2afe910..f28b2e251b 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -555,7 +555,7 @@ EXPORT_SYMBOL(acpi_map_lsapic); int acpi_unmap_lsapic(int cpu) { - x86_cpu_to_apicid[cpu] = -1; + per_cpu(x86_cpu_to_apicid, cpu) = -1; cpu_clear(cpu, cpu_present_map); num_processors--; diff --git a/arch/x86/kernel/genapic_64.c b/arch/x86/kernel/genapic_64.c index 4ae03e3e82..ce703e21c9 100644 --- a/arch/x86/kernel/genapic_64.c +++ b/arch/x86/kernel/genapic_64.c @@ -24,10 +24,19 @@ #include #endif -/* which logical CPU number maps to which CPU (physical APIC ID) */ -u8 x86_cpu_to_apicid[NR_CPUS] __read_mostly +/* + * which logical CPU number maps to which CPU (physical APIC ID) + * + * The following static array is used during kernel startup + * and the x86_cpu_to_apicid_ptr contains the address of the + * array during this time. Is it zeroed when the per_cpu + * data area is removed. + */ +u8 x86_cpu_to_apicid_init[NR_CPUS] __initdata = { [0 ... NR_CPUS-1] = BAD_APICID }; -EXPORT_SYMBOL(x86_cpu_to_apicid); +void *x86_cpu_to_apicid_ptr; +DEFINE_PER_CPU(u8, x86_cpu_to_apicid) = BAD_APICID; +EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid); struct genapic __read_mostly *genapic = &apic_flat; diff --git a/arch/x86/kernel/genapic_flat_64.c b/arch/x86/kernel/genapic_flat_64.c index 91c7526768..07352b74bd 100644 --- a/arch/x86/kernel/genapic_flat_64.c +++ b/arch/x86/kernel/genapic_flat_64.c @@ -172,7 +172,7 @@ static unsigned int physflat_cpu_mask_to_apicid(cpumask_t cpumask) */ cpu = first_cpu(cpumask); if ((unsigned)cpu < NR_CPUS) - return x86_cpu_to_apicid[cpu]; + return per_cpu(x86_cpu_to_apicid, cpu); else return BAD_APICID; } diff --git a/arch/x86/kernel/mpparse_64.c b/arch/x86/kernel/mpparse_64.c index 8bf0ca03ac..4336c0fc3b 100644 --- a/arch/x86/kernel/mpparse_64.c +++ b/arch/x86/kernel/mpparse_64.c @@ -86,7 +86,7 @@ static int __init mpf_checksum(unsigned char *mp, int len) return sum & 0xFF; } -static void __cpuinit MP_processor_info (struct mpc_config_processor *m) +static void __cpuinit MP_processor_info(struct mpc_config_processor *m) { int cpu; cpumask_t tmp_map; @@ -123,7 +123,18 @@ static void __cpuinit MP_processor_info (struct mpc_config_processor *m) cpu = 0; } bios_cpu_apicid[cpu] = m->mpc_apicid; - x86_cpu_to_apicid[cpu] = m->mpc_apicid; + /* + * We get called early in the the start_kernel initialization + * process when the per_cpu data area is not yet setup, so we + * use a static array that is removed after the per_cpu data + * area is created. + */ + if (x86_cpu_to_apicid_ptr) { + u8 *x86_cpu_to_apicid = (u8 *)x86_cpu_to_apicid_ptr; + x86_cpu_to_apicid[cpu] = m->mpc_apicid; + } else { + per_cpu(x86_cpu_to_apicid, cpu) = m->mpc_apicid; + } cpu_set(cpu, cpu_possible_map); cpu_set(cpu, cpu_present_map); diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c index 5a19f0cc5b..94630c6647 100644 --- a/arch/x86/kernel/setup_64.c +++ b/arch/x86/kernel/setup_64.c @@ -271,6 +271,11 @@ void __init setup_arch(char **cmdline_p) dmi_scan_machine(); +#ifdef CONFIG_SMP + /* setup to use the static apicid table during kernel startup */ + x86_cpu_to_apicid_ptr = (void *)&x86_cpu_to_apicid_init; +#endif + #ifdef CONFIG_ACPI /* * Initialize the ACPI boot-time table parser (gets the RSDP and SDT). diff --git a/arch/x86/kernel/smp_32.c b/arch/x86/kernel/smp_32.c index 791d9f8036..4974c3d2a0 100644 --- a/arch/x86/kernel/smp_32.c +++ b/arch/x86/kernel/smp_32.c @@ -676,7 +676,7 @@ static int convert_apicid_to_cpu(int apic_id) int i; for (i = 0; i < NR_CPUS; i++) { - if (x86_cpu_to_apicid[i] == apic_id) + if (per_cpu(x86_cpu_to_apicid, i) == apic_id) return i; } return -1; diff --git a/arch/x86/kernel/smpboot_32.c b/arch/x86/kernel/smpboot_32.c index 65e5de7d64..631be36ec2 100644 --- a/arch/x86/kernel/smpboot_32.c +++ b/arch/x86/kernel/smpboot_32.c @@ -92,9 +92,17 @@ static cpumask_t smp_commenced_mask; struct cpuinfo_x86 cpu_data[NR_CPUS] __cacheline_aligned; EXPORT_SYMBOL(cpu_data); -u8 x86_cpu_to_apicid[NR_CPUS] __read_mostly = - { [0 ... NR_CPUS-1] = 0xff }; -EXPORT_SYMBOL(x86_cpu_to_apicid); +/* + * The following static array is used during kernel startup + * and the x86_cpu_to_apicid_ptr contains the address of the + * array during this time. Is it zeroed when the per_cpu + * data area is removed. + */ +u8 x86_cpu_to_apicid_init[NR_CPUS] __initdata = + { [0 ... NR_CPUS-1] = BAD_APICID }; +void *x86_cpu_to_apicid_ptr; +DEFINE_PER_CPU(u8, x86_cpu_to_apicid) = BAD_APICID; +EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid); u8 apicid_2_node[MAX_APICID]; @@ -804,7 +812,7 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu) irq_ctx_init(cpu); - x86_cpu_to_apicid[cpu] = apicid; + per_cpu(x86_cpu_to_apicid, cpu) = apicid; /* * This grunge runs the startup process for * the targeted processor. @@ -866,7 +874,7 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu) cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */ cpucount--; } else { - x86_cpu_to_apicid[cpu] = apicid; + per_cpu(x86_cpu_to_apicid, cpu) = apicid; cpu_set(cpu, cpu_present_map); } @@ -915,7 +923,7 @@ static int __cpuinit __smp_prepare_cpu(int cpu) struct warm_boot_cpu_info info; int apicid, ret; - apicid = x86_cpu_to_apicid[cpu]; + apicid = per_cpu(x86_cpu_to_apicid, cpu); if (apicid == BAD_APICID) { ret = -ENODEV; goto exit; @@ -965,7 +973,7 @@ static void __init smp_boot_cpus(unsigned int max_cpus) boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID)); boot_cpu_logical_apicid = logical_smp_processor_id(); - x86_cpu_to_apicid[0] = boot_cpu_physical_apicid; + per_cpu(x86_cpu_to_apicid, 0) = boot_cpu_physical_apicid; current_thread_info()->cpu = 0; diff --git a/arch/x86/kernel/smpboot_64.c b/arch/x86/kernel/smpboot_64.c index e351ac4ab5..c3e8668c52 100644 --- a/arch/x86/kernel/smpboot_64.c +++ b/arch/x86/kernel/smpboot_64.c @@ -694,7 +694,7 @@ do_rest: clear_node_cpumask(cpu); /* was set by numa_add_cpu */ cpu_clear(cpu, cpu_present_map); cpu_clear(cpu, cpu_possible_map); - x86_cpu_to_apicid[cpu] = BAD_APICID; + per_cpu(x86_cpu_to_apicid, cpu) = BAD_APICID; return -EIO; } @@ -840,6 +840,26 @@ static int __init smp_sanity_check(unsigned max_cpus) return 0; } +/* + * Copy apicid's found by MP_processor_info from initial array to the per cpu + * data area. The x86_cpu_to_apicid_init array is then expendable and the + * x86_cpu_to_apicid_ptr is zeroed indicating that the static array is no + * longer available. + */ +void __init smp_set_apicids(void) +{ + int cpu; + + for_each_cpu_mask(cpu, cpu_possible_map) { + if (per_cpu_offset(cpu)) + per_cpu(x86_cpu_to_apicid, cpu) = + x86_cpu_to_apicid_init[cpu]; + } + + /* indicate the static array will be going away soon */ + x86_cpu_to_apicid_ptr = NULL; +} + /* * Prepare for SMP bootup. The MP table or ACPI has been read * earlier. Just do some sanity checking here and enable APIC mode. @@ -849,6 +869,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus) nmi_watchdog_default(); current_cpu_data = boot_cpu_data; current_thread_info()->cpu = 0; /* needed? */ + smp_set_apicids(); set_cpu_sibling_map(0); if (smp_sanity_check(max_cpus) < 0) { diff --git a/arch/x86/mm/numa_64.c b/arch/x86/mm/numa_64.c index 5eec5e56d0..3d6926ba89 100644 --- a/arch/x86/mm/numa_64.c +++ b/arch/x86/mm/numa_64.c @@ -612,7 +612,7 @@ void __init init_cpu_to_node(void) { int i; for (i = 0; i < NR_CPUS; i++) { - u8 apicid = x86_cpu_to_apicid[i]; + u8 apicid = x86_cpu_to_apicid_init[i]; if (apicid == BAD_APICID) continue; if (apicid_to_node[apicid] == NUMA_NO_NODE) diff --git a/include/asm-x86/ipi.h b/include/asm-x86/ipi.h index a7c75ea408..6d011bd606 100644 --- a/include/asm-x86/ipi.h +++ b/include/asm-x86/ipi.h @@ -119,7 +119,7 @@ static inline void send_IPI_mask_sequence(cpumask_t mask, int vector) */ local_irq_save(flags); for_each_cpu_mask(query_cpu, mask) { - __send_IPI_dest_field(x86_cpu_to_apicid[query_cpu], + __send_IPI_dest_field(per_cpu(x86_cpu_to_apicid, query_cpu), vector, APIC_DEST_PHYSICAL); } local_irq_restore(flags); diff --git a/include/asm-x86/smp_32.h b/include/asm-x86/smp_32.h index ee46038d12..9006f6041b 100644 --- a/include/asm-x86/smp_32.h +++ b/include/asm-x86/smp_32.h @@ -39,9 +39,11 @@ extern void lock_ipi_call_lock(void); extern void unlock_ipi_call_lock(void); #define MAX_APICID 256 -extern u8 x86_cpu_to_apicid[]; +extern u8 __initdata x86_cpu_to_apicid_init[]; +extern void *x86_cpu_to_apicid_ptr; +DECLARE_PER_CPU(u8, x86_cpu_to_apicid); -#define cpu_physical_id(cpu) x86_cpu_to_apicid[cpu] +#define cpu_physical_id(cpu) per_cpu(x86_cpu_to_apicid, cpu) extern void set_cpu_sibling_map(int cpu); diff --git a/include/asm-x86/smp_64.h b/include/asm-x86/smp_64.h index 9d35018e54..f1545704e2 100644 --- a/include/asm-x86/smp_64.h +++ b/include/asm-x86/smp_64.h @@ -86,7 +86,9 @@ static inline int hard_smp_processor_id(void) * Some lowlevel functions might want to know about * the real APIC ID <-> CPU # mapping. */ -extern u8 x86_cpu_to_apicid[NR_CPUS]; /* physical ID */ +extern u8 __initdata x86_cpu_to_apicid_init[]; +extern void *x86_cpu_to_apicid_ptr; +DECLARE_PER_CPU(u8, x86_cpu_to_apicid); /* physical ID */ extern u8 bios_cpu_apicid[]; static inline int cpu_present_to_apicid(int mps_cpu) @@ -117,7 +119,7 @@ static __inline int logical_smp_processor_id(void) } #ifdef CONFIG_SMP -#define cpu_physical_id(cpu) x86_cpu_to_apicid[cpu] +#define cpu_physical_id(cpu) per_cpu(x86_cpu_to_apicid, cpu) #else #define cpu_physical_id(cpu) boot_cpu_id #endif /* !CONFIG_SMP */