alistair23-linux/arch/arm/mach-shmobile/smp-sh73a0.c

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/*
* SMP support for R-Mobile / SH-Mobile - sh73a0 portion
*
* Copyright (C) 2010 Magnus Damm
* Copyright (C) 2010 Takashi Yoshii
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <asm/smp_plat.h>
#include <asm/smp_twd.h>
#include "common.h"
#include "sh73a0.h"
#define WUPCR IOMEM(0xe6151010)
#define SRESCR IOMEM(0xe6151018)
#define PSTR IOMEM(0xe6151040)
#define SBAR IOMEM(0xe6180020)
#define APARMBAREA IOMEM(0xe6f10020)
#define SH73A0_SCU_BASE 0xf0000000
arm: delete __cpuinit/__CPUINIT usage from all ARM users The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the ARM uses of the __cpuinit macros from C code, and all __CPUINIT from assembly code. It also had two ".previous" section statements that were paired off against __CPUINIT (aka .section ".cpuinit.text") that also get removed here. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2013-06-17 13:43:14 -06:00
static int sh73a0_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
unsigned int lcpu = cpu_logical_map(cpu);
if (((__raw_readl(PSTR) >> (4 * lcpu)) & 3) == 3)
__raw_writel(1 << lcpu, WUPCR); /* wake up */
else
__raw_writel(1 << lcpu, SRESCR); /* reset */
return 0;
}
static void __init sh73a0_smp_prepare_cpus(unsigned int max_cpus)
{
/* Map the reset vector (in headsmp.S) */
__raw_writel(0, APARMBAREA); /* 4k */
__raw_writel(__pa(shmobile_boot_vector), SBAR);
/* setup sh73a0 specific SCU bits */
shmobile_scu_base = IOMEM(SH73A0_SCU_BASE);
shmobile_smp_scu_prepare_cpus(max_cpus);
}
struct smp_operations sh73a0_smp_ops __initdata = {
.smp_prepare_cpus = sh73a0_smp_prepare_cpus,
.smp_boot_secondary = sh73a0_boot_secondary,
#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 17:34:48 -06:00
.cpu_can_disable = shmobile_smp_cpu_can_disable,
.cpu_die = shmobile_smp_scu_cpu_die,
.cpu_kill = shmobile_smp_scu_cpu_kill,
#endif
};