diff options
| author | Will Deacon <will.deacon@arm.com> | 2011-08-23 22:19:29 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-10-17 09:02:43 +0100 |
| commit | d6257288c4052465feeff7e283e35ec0ed06ca03 (patch) | |
| tree | e9dbc251dfb47716d592681d228bda73a3a63121 /arch | |
| parent | c9018aab8eee24b993c12c7aff7fc99d3d73f298 (diff) | |
ARM: 7060/1: smp: populate logical CPU mapping during boot
To allow booting Linux on a CPU with physical ID != 0, we need to
provide a mapping from the logical CPU number to the physical CPU
number.
This patch adds such a mapping and populates it during boot.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/include/asm/smp.h | 6 | ||||
| -rw-r--r-- | arch/arm/kernel/smp.c | 15 |
2 files changed, 21 insertions, 0 deletions
diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index e42d96a45d3e..674ebcd337fe 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -66,6 +66,12 @@ extern void platform_secondary_init(unsigned int cpu); extern void platform_smp_prepare_cpus(unsigned int); /* + * Logical CPU mapping. + */ +extern int __cpu_logical_map[NR_CPUS]; +#define cpu_logical_map(cpu) __cpu_logical_map[cpu] + +/* * Initial data for bringing up a secondary CPU. */ struct secondary_data { diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index 62775c5c5ba0..3f12ce9b0796 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -40,6 +40,7 @@ #include <asm/tlbflush.h> #include <asm/ptrace.h> #include <asm/localtimer.h> +#include <asm/smp_plat.h> /* * as from 2.5, kernels no longer have an init_tasks structure @@ -260,6 +261,20 @@ void __ref cpu_die(void) } #endif /* CONFIG_HOTPLUG_CPU */ +int __cpu_logical_map[NR_CPUS]; + +void __init smp_setup_processor_id(void) +{ + int i; + u32 cpu = is_smp() ? read_cpuid_mpidr() & 0xff : 0; + + cpu_logical_map(0) = cpu; + for (i = 1; i < NR_CPUS; ++i) + cpu_logical_map(i) = i == cpu ? 0 : i; + + printk(KERN_INFO "Booting Linux on physical CPU %d\n", cpu); +} + /* * Called by both boot and secondaries to move global data into * per-processor storage. |