From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc_gonzalez@sigmadesigns.com (Marc Gonzalez) Date: Tue, 28 Jun 2016 13:59:41 +0200 Subject: [PATCH v3 1/2] ARM: tango: add HOTPLUG_CPU support In-Reply-To: <57726597.8030501@sigmadesigns.com> References: <57726597.8030501@sigmadesigns.com> Message-ID: <577266AD.8000006@sigmadesigns.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org cpu_die() and cpu_kill() are implemented in firmware. Signed-off-by: Marc Gonzalez --- arch/arm/mach-tango/platsmp.c | 30 ++++++++++++++++++++++++++++++ arch/arm/mach-tango/smc.h | 4 +++- 2 files changed, 33 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-tango/platsmp.c b/arch/arm/mach-tango/platsmp.c index a21f55e000d2..a24b9b1d0b1a 100644 --- a/arch/arm/mach-tango/platsmp.c +++ b/arch/arm/mach-tango/platsmp.c @@ -1,3 +1,4 @@ +#include #include #include #include "smc.h" @@ -9,8 +10,37 @@ static int tango_boot_secondary(unsigned int cpu, struct task_struct *idle) return 0; } +#ifdef CONFIG_HOTPLUG_CPU +/* + * cpu_kill() and cpu_die() run concurrently on different cores. + * Firmware will only "kill" a core once it has properly "died". + * Keep trying to kill a core until the operation succeeds, but + * sleep between tries to give the core time to die. + */ +static int tango_cpu_kill(unsigned int cpu) +{ + do { + msleep(10); + } while (tango_aux_core_kill(cpu) != 0); + + return 1; +} + +static void tango_cpu_die(unsigned int cpu) +{ + do { + cpu_relax(); + } while (tango_aux_core_die(cpu) != 0); +} +#else +#define tango_cpu_kill NULL +#define tango_cpu_die NULL +#endif + static const struct smp_operations tango_smp_ops __initconst = { .smp_boot_secondary = tango_boot_secondary, + .cpu_kill = tango_cpu_kill, + .cpu_die = tango_cpu_die, }; CPU_METHOD_OF_DECLARE(tango4_smp, "sigma,tango4-smp", &tango_smp_ops); diff --git a/arch/arm/mach-tango/smc.h b/arch/arm/mach-tango/smc.h index 7a4af35cc390..3d31f984f44c 100644 --- a/arch/arm/mach-tango/smc.h +++ b/arch/arm/mach-tango/smc.h @@ -2,4 +2,6 @@ extern int tango_smc(unsigned int val, unsigned int service); #define tango_set_l2_control(val) tango_smc(val, 0x102) #define tango_start_aux_core(val) tango_smc(val, 0x104) -#define tango_set_aux_boot_addr(val) tango_smc((unsigned int)val, 0x105) +#define tango_set_aux_boot_addr(val) tango_smc(val, 0x105) +#define tango_aux_core_die(val) tango_smc(val, 0x121) +#define tango_aux_core_kill(val) tango_smc(val, 0x122) -- 2.9.0