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linux/arch/arm/mach-shmobile/platsmp.c

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ARM: mach-shmobile: SMP base support Add SMP base support for R-Mobile / SH-Mobile processors. This patch contains all base code to support CONFIG_SMP regardless of ARCH_SHMOBILE processor type. Both local timer and CPU hotplug are supported, but no processor specific code is included. At this point only the default behavior is in place, so a single core will always be used even though CONFIG_SMP is enabled on multicore systems. The SMP Kconfig entry for arch/arm/Kconfig is excluded from this patch to simplify merging. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-12-14 07:56:55 +00:00
/*
* SMP support for R-Mobile / SH-Mobile
*
* Copyright (C) 2010 Magnus Damm
ARM: mach-shmobile: update for SMP changes. There have likewise been some API updates, so we refactor to use the consolidated smp_prepare_cpus(). Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2011-01-07 03:03:22 +00:00
* Copyright (C) 2011 Paul Mundt
ARM: mach-shmobile: SMP base support Add SMP base support for R-Mobile / SH-Mobile processors. This patch contains all base code to support CONFIG_SMP regardless of ARCH_SHMOBILE processor type. Both local timer and CPU hotplug are supported, but no processor specific code is included. At this point only the default behavior is in place, so a single core will always be used even though CONFIG_SMP is enabled on multicore systems. The SMP Kconfig entry for arch/arm/Kconfig is excluded from this patch to simplify merging. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-12-14 07:56:55 +00:00
*
* Based on vexpress, Copyright (C) 2002 ARM Ltd, All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
ARM: shmobile: Introduce per-CPU SMP boot / sleep code Add per-CPU SMP boot / sleep code that can be used by all SoCs included in mach-shmobile. The boot code reads out the per-CPU MPIDR id value and matches it with the value stored for any CPU number, and if there is a match and the boot function is set as well then the boot function will be executed. The sleep code simply uses WFI and then jumps back to the boot code to see if anyone has asked to wake up that CPU, if not it will sleep again. Signed-off-by: Magnus Damm <damm@opensource.se> [horms+renesas@verge.net.au: Remove trailing whitespace] Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-07-31 18:38:18 +00:00
#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
ARM: shmobile: Move common.h Change location for common.h so it can be used as #include "common.h" instead of the old style #include <mach/common.h>. Signed-off-by: Magnus Damm <damm+renesas@opensource.se> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2014-06-17 07:47:37 +00:00
#include "common.h"
ARM: mach-shmobile: SMP base support Add SMP base support for R-Mobile / SH-Mobile processors. This patch contains all base code to support CONFIG_SMP regardless of ARCH_SHMOBILE processor type. Both local timer and CPU hotplug are supported, but no processor specific code is included. At this point only the default behavior is in place, so a single core will always be used even though CONFIG_SMP is enabled on multicore systems. The SMP Kconfig entry for arch/arm/Kconfig is excluded from this patch to simplify merging. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-12-14 07:56:55 +00:00
ARM: shmobile: Introduce per-CPU SMP boot / sleep code Add per-CPU SMP boot / sleep code that can be used by all SoCs included in mach-shmobile. The boot code reads out the per-CPU MPIDR id value and matches it with the value stored for any CPU number, and if there is a match and the boot function is set as well then the boot function will be executed. The sleep code simply uses WFI and then jumps back to the boot code to see if anyone has asked to wake up that CPU, if not it will sleep again. Signed-off-by: Magnus Damm <damm@opensource.se> [horms+renesas@verge.net.au: Remove trailing whitespace] Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-07-31 18:38:18 +00:00
extern unsigned long shmobile_smp_fn[];
extern unsigned long shmobile_smp_arg[];
extern unsigned long shmobile_smp_mpidr[];
void shmobile_smp_hook(unsigned int cpu, unsigned long fn, unsigned long arg)
{
shmobile_smp_fn[cpu] = 0;
flush_cache_all();
shmobile_smp_mpidr[cpu] = cpu_logical_map(cpu);
shmobile_smp_fn[cpu] = fn;
shmobile_smp_arg[cpu] = arg;
flush_cache_all();
}
ARM: shmobile: Introduce shmobile_smp_cpu_disable() Introduce the shared CPU Hotplug function shmobile_smp_cpu_disable() for mach-shmobile. It is useful for the case when all CPUs may be hotplugged, including CPU 0. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-08-07 22:13:30 +00:00
#ifdef CONFIG_HOTPLUG_CPU
ARM: 8392/3: smp: Only expose /sys/.../cpuX/online if hotpluggable Writes to /sys/.../cpuX/online fail if we determine the platform doesn't support hotplug for that CPU. Furthermore, if the cpu_die op isn't specified the system hangs when we try to offline a CPU and it comes right back online unexpectedly. Let's figure this stuff out before we make the sysfs nodes so that the online file doesn't even exist if it isn't (at least sometimes) possible to hotplug the CPU. Add a new 'cpu_can_disable' op and repoint all 'cpu_disable' implementations at it because all implementers use the op to indicate if a CPU can be hotplugged or not in a static fashion. With PSCI we may need to add a 'cpu_disable' op so that the secure OS can be migrated off the CPU we're trying to hotplug. In this case, the 'cpu_can_disable' op will indicate that all CPUs are hotpluggable by returning true, but the 'cpu_disable' op will make a PSCI migration call and occasionally fail, denying the hotplug of a CPU. This shouldn't be any worse than x86 where we may indicate that all CPUs are hotpluggable but occasionally we can't offline a CPU due to check_irq_vectors_for_cpu_disable() failing to find a CPU to move vectors to. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Nicolas Pitre <nico@linaro.org> Cc: Dave Martin <Dave.Martin@arm.com> Acked-by: Simon Horman <horms@verge.net.au> [shmobile portion] Tested-by: Simon Horman <horms@verge.net.au> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: <linux-sh@vger.kernel.org> Tested-by: Tyler Baker <tyler.baker@linaro.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-07-28 23:34:48 +00:00
bool shmobile_smp_cpu_can_disable(unsigned int cpu)
ARM: shmobile: Introduce shmobile_smp_cpu_disable() Introduce the shared CPU Hotplug function shmobile_smp_cpu_disable() for mach-shmobile. It is useful for the case when all CPUs may be hotplugged, including CPU 0. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-08-07 22:13:30 +00:00
{
ARM: 8392/3: smp: Only expose /sys/.../cpuX/online if hotpluggable Writes to /sys/.../cpuX/online fail if we determine the platform doesn't support hotplug for that CPU. Furthermore, if the cpu_die op isn't specified the system hangs when we try to offline a CPU and it comes right back online unexpectedly. Let's figure this stuff out before we make the sysfs nodes so that the online file doesn't even exist if it isn't (at least sometimes) possible to hotplug the CPU. Add a new 'cpu_can_disable' op and repoint all 'cpu_disable' implementations at it because all implementers use the op to indicate if a CPU can be hotplugged or not in a static fashion. With PSCI we may need to add a 'cpu_disable' op so that the secure OS can be migrated off the CPU we're trying to hotplug. In this case, the 'cpu_can_disable' op will indicate that all CPUs are hotpluggable by returning true, but the 'cpu_disable' op will make a PSCI migration call and occasionally fail, denying the hotplug of a CPU. This shouldn't be any worse than x86 where we may indicate that all CPUs are hotpluggable but occasionally we can't offline a CPU due to check_irq_vectors_for_cpu_disable() failing to find a CPU to move vectors to. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Nicolas Pitre <nico@linaro.org> Cc: Dave Martin <Dave.Martin@arm.com> Acked-by: Simon Horman <horms@verge.net.au> [shmobile portion] Tested-by: Simon Horman <horms@verge.net.au> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: <linux-sh@vger.kernel.org> Tested-by: Tyler Baker <tyler.baker@linaro.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-07-28 23:34:48 +00:00
return true; /* Hotplug of any CPU is supported */
ARM: shmobile: Introduce shmobile_smp_cpu_disable() Introduce the shared CPU Hotplug function shmobile_smp_cpu_disable() for mach-shmobile. It is useful for the case when all CPUs may be hotplugged, including CPU 0. Signed-off-by: Magnus Damm <damm@opensource.se> Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2013-08-07 22:13:30 +00:00
}
#endif
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