[PATCH 02/21] ARM: shmobile: Convert to hotplug state machine
From: geert@linux-m68k.org (Geert Uytterhoeven)
Date: 2016-09-06 18:05:41
Also in:
linux-renesas-soc, linux-sh, lkml
Hi Sebastian, CC linux-renesas-soc On Tue, Sep 6, 2016 at 7:04 PM, Sebastian Andrzej Siewior [off-list ref] wrote:
Install the callbacks via the state machine.
Please describe why this is desirable.
quoted hunk ↗ jump to hunk
Cc: Simon Horman <horms@verge.net.au> Cc: Magnus Damm <magnus.damm@gmail.com> Cc: linux-arm-kernel at lists.infradead.org Cc: linux-sh at vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- arch/arm/mach-shmobile/platsmp-scu.c | 26 ++++++++------------------ include/linux/cpuhotplug.h | 1 + 2 files changed, 9 insertions(+), 18 deletions(-)diff --git a/arch/arm/mach-shmobile/platsmp-scu.c b/arch/arm/mach-shmobile/platsmp-scu.c index 8d478f1da265..d1ecaf37d142 100644 --- a/arch/arm/mach-shmobile/platsmp-scu.c +++ b/arch/arm/mach-shmobile/platsmp-scu.c@@ -21,26 +21,14 @@ static phys_addr_t shmobile_scu_base_phys; static void __iomem *shmobile_scu_base; -static int shmobile_smp_scu_notifier_call(struct notifier_block *nfb, - unsigned long action, void *hcpu) +static int shmobile_scu_cpu_prepare(unsigned int cpu) { - unsigned int cpu = (long)hcpu; - - switch (action) { - case CPU_UP_PREPARE: - /* For this particular CPU register SCU SMP boot vector */ - shmobile_smp_hook(cpu, virt_to_phys(shmobile_boot_scu), - shmobile_scu_base_phys); - break; - }; - - return NOTIFY_OK; + /* For this particular CPU register SCU SMP boot vector */ + shmobile_smp_hook(cpu, virt_to_phys(shmobile_boot_scu), + shmobile_scu_base_phys); + return 0; } -static struct notifier_block shmobile_smp_scu_notifier = { - .notifier_call = shmobile_smp_scu_notifier_call, -}; - void __init shmobile_smp_scu_prepare_cpus(phys_addr_t scu_base_phys, unsigned int max_cpus) {@@ -54,7 +42,9 @@ void __init shmobile_smp_scu_prepare_cpus(phys_addr_t scu_base_phys, scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL); /* Use CPU notifier for reset vector control */ - register_cpu_notifier(&shmobile_smp_scu_notifier); + cpuhp_setup_state_nocalls(CPUHP_ARM_SHMOBILE_SCU_PREPARE, + "arm/shmobile-scu:prepare", + shmobile_scu_cpu_prepare, NULL); } #ifdef CONFIG_HOTPLUG_CPUdiff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h index 0da071ff36d2..008eed0c0787 100644 --- a/include/linux/cpuhotplug.h +++ b/include/linux/cpuhotplug.h@@ -35,6 +35,7 @@ enum cpuhp_state { CPUHP_POWERPC_PMAC_PREPARE, CPUHP_POWERPC_MMU_CTX_PREPARE, CPUHP_NOTIFY_PREPARE, + CPUHP_ARM_SHMOBILE_SCU_PREPARE, CPUHP_TIMERS_DEAD, CPUHP_BRINGUP_CPU, CPUHP_AP_IDLE_DEAD,
What's the rationale behind adding all these numbers and always
iterating over all
of them, even though most/all of them cannot be used at the same time
(e.g. CPUHP_SH_SH3X_PREPARE is for SuperH, while
CPUHP_ARM_SHMOBILE_SCU_PREPARE is for ARM)?
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds