From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Gonzalez Subject: [PATCH v4 1/2] ARM: tango: add HOTPLUG_CPU support Date: Wed, 29 Jun 2016 14:21:42 +0200 Message-ID: <5773BD56.5040104@sigmadesigns.com> References: <57726597.8030501@sigmadesigns.com> <577266AD.8000006@sigmadesigns.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <577266AD.8000006@sigmadesigns.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: arm-soc Cc: Mark Rutland , Sebastian Frias , linux-pm , Thibaud Cornic , Mason , Robin Murphy , Linux ARM List-Id: linux-pm@vger.kernel.org cpu_die() and cpu_kill() are implemented in firmware. Signed-off-by: Marc Gonzalez --- New in v4: o panic() if tango_cpu_die() returns unexpectedly o timeout after 10 tries in tango_cpu_kill() --- arch/arm/mach-tango/platsmp.c | 36 ++++++++++++++++++++++++++++++++++++ arch/arm/mach-tango/smc.h | 4 +++- 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/arch/arm/mach-tango/platsmp.c b/arch/arm/mach-tango/platsmp.c index a21f55e000d2..8380699d4fa3 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 +10,43 @@ 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". + * Try a few times to kill a core before giving up, and sleep + * between tries to give that core enough time to die. + */ +static int tango_cpu_kill(unsigned int cpu) +{ + int i, err; + + for (i = 0; i < 10; ++i) { + msleep(10); + err = tango_aux_core_kill(cpu); + if (!err) + return true; + } + + return false; +} + +static void tango_cpu_die(unsigned int cpu) +{ + while (tango_aux_core_die(cpu) < 0) + cpu_relax(); + + panic("cpu %d failed to die\n", cpu); +} +#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