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authorWill Deacon <will.deacon@arm.com>2011-08-23 22:19:29 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-10-17 09:02:43 +0100
commitd6257288c4052465feeff7e283e35ec0ed06ca03 (patch)
treee9dbc251dfb47716d592681d228bda73a3a63121 /arch/arm
parentc9018aab8eee24b993c12c7aff7fc99d3d73f298 (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/arm')
-rw-r--r--arch/arm/include/asm/smp.h6
-rw-r--r--arch/arm/kernel/smp.c15
2 files changed, 21 insertions, 0 deletions
diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h
index e42d96a45d3..674ebcd337f 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 62775c5c5ba..3f12ce9b079 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.