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authorMagnus Damm <damm@opensource.se>2014-02-26 18:59:16 +0900
committerSimon Horman <horms+renesas@verge.net.au>2014-04-14 11:28:43 +0900
commit277efd30cfc72ec2f44a9bc95d93807b867bd9e9 (patch)
tree012366acc7e369a872e91cdebd3c4bf30d38fc62 /arch/arm/mach-shmobile
parent835d737d664650d7f164a5b688271a424db4434c (diff)
ARM: shmobile: Check r8a7791 MD21 at SMP boot
On r8a7791 the hardware boot mode bit MD21 indicates if hardware debug mode is enabled or not. In case hardware debug mode is enabled print a warning and refrain from booting secondary CPU cores. Without this patch Koelsch with SW8-4 set to OFF will hang at SMP boot. Signed-off-by: Magnus Damm <damm@opensource.se> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
Diffstat (limited to 'arch/arm/mach-shmobile')
-rw-r--r--arch/arm/mach-shmobile/smp-r8a7791.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/arch/arm/mach-shmobile/smp-r8a7791.c b/arch/arm/mach-shmobile/smp-r8a7791.c
index 2df5bd190fe4..ec979529f30f 100644
--- a/arch/arm/mach-shmobile/smp-r8a7791.c
+++ b/arch/arm/mach-shmobile/smp-r8a7791.c
@@ -20,6 +20,7 @@
#include <asm/smp_plat.h>
#include <mach/common.h>
#include <mach/r8a7791.h>
+#include <mach/rcar-gen2.h>
#define RST 0xe6160000
#define CA15BAR 0x0020
@@ -51,9 +52,21 @@ static void __init r8a7791_smp_prepare_cpus(unsigned int max_cpus)
iounmap(p);
}
+static int r8a7791_smp_boot_secondary(unsigned int cpu,
+ struct task_struct *idle)
+{
+ /* Error out when hardware debug mode is enabled */
+ if (rcar_gen2_read_mode_pins() & BIT(21)) {
+ pr_warn("Unable to boot CPU%u when MD21 is set\n", cpu);
+ return -ENOTSUPP;
+ }
+
+ return shmobile_smp_apmu_boot_secondary(cpu, idle);
+}
+
struct smp_operations r8a7791_smp_ops __initdata = {
.smp_prepare_cpus = r8a7791_smp_prepare_cpus,
- .smp_boot_secondary = shmobile_smp_apmu_boot_secondary,
+ .smp_boot_secondary = r8a7791_smp_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_disable = shmobile_smp_cpu_disable,
.cpu_die = shmobile_smp_apmu_cpu_die,