From cb45babe1b80090fd0272da76bf39e781439f1d6 Mon Sep 17 00:00:00 2001 From: Anshuman Khandual Date: Mon, 9 Nov 2020 09:58:55 +0530 Subject: [PATCH] arm64/mm/hotplug: Register boot memory hot remove notifier earlier This moves memory notifier registration earlier in the boot process from device_initcall() to early_initcall() which will help in guarding against potential early boot memory offline requests. Even though there should not be any actual offlinig requests till memory block devices are initialized with memory_dev_init() but then generic init sequence might just change in future. Hence an early registration for the memory event notifier would be helpful. While here, just skip the registration if CONFIG_MEMORY_HOTREMOVE is not enabled and also call out when memory notifier registration fails. Signed-off-by: Anshuman Khandual Reviewed-by: Gavin Shan Reviewed-by: Catalin Marinas Cc: Will Deacon Cc: Mark Rutland Cc: Marc Zyngier Cc: Steve Capper Cc: Mark Brown Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Link: https://lore.kernel.org/r/1604896137-16644-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Catalin Marinas --- arch/arm64/mm/mmu.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 1c0f3e02f731..71dd9d753b8b 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1510,7 +1510,16 @@ static struct notifier_block prevent_bootmem_remove_nb = { static int __init prevent_bootmem_remove_init(void) { - return register_memory_notifier(&prevent_bootmem_remove_nb); + int ret = 0; + + if (!IS_ENABLED(CONFIG_MEMORY_HOTREMOVE)) + return ret; + + ret = register_memory_notifier(&prevent_bootmem_remove_nb); + if (ret) + pr_err("%s: Notifier registration failed %d\n", __func__, ret); + + return ret; } -device_initcall(prevent_bootmem_remove_init); +early_initcall(prevent_bootmem_remove_init); #endif