The patch below was submitted to be applied to the 4.14-stable tree.

I fail to see how this patch meets the stable kernel rules as found at Documentation/process/stable-kernel-rules.rst.

I could be totally wrong, and if so, please respond to stable@vger.kernel.org and let me know why this patch should be applied. Otherwise, it is now dropped from my patch queues, never to be seen again.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 18b4b276b490a8b9f86c512de8a6054c27bb87c2 Mon Sep 17 00:00:00 2001

From: James Morse james.morse@arm.com Date: Mon, 6 Nov 2017 18:44:26 +0000 Subject: [PATCH] arm64: mm: Remove arch_apei_flush_tlb_one()

Nothing calls arch_apei_flush_tlb_one() anymore, instead relying on __set_fixmap() to do the invalidation. Remove it.

Move the IPI-considered-harmful comment to __set_fixmap().

Signed-off-by: James Morse james.morse@arm.com Acked-by: Will Deacon will.deacon@arm.com Tested-by: Tyler Baicar tbaicar@codeaurora.org Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Cc: All applicable stable@vger.kernel.org

diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 59cca1d6ec54..32f465a80e4e 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -126,18 +126,6 @@ static inline const char *acpi_get_enable_method(int cpu) */ #define acpi_disable_cmcff 1 pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr); - -/* - * Despite its name, this function must still broadcast the TLB - * invalidation in order to ensure other CPUs don't end up with junk - * entries as a result of speculation. Unusually, its also called in - * IRQ context (ghes_iounmap_irq) so if we ever need to use IPIs for - * TLB broadcasting, then we're in trouble here. - */ -static inline void arch_apei_flush_tlb_one(unsigned long addr) -{ - flush_tlb_kernel_range(addr, addr + PAGE_SIZE); -} #endif /* CONFIG_ACPI_APEI */

#ifdef CONFIG_ACPI_NUMA diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index f1eb15e0e864..267d2b79d52d 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -778,6 +778,10 @@ void __init early_fixmap_init(void) } }

+/* + * Unusually, this is also called in IRQ context (ghes_iounmap_irq) so if we + * ever need to use IPIs for TLB broadcasting, then we're in trouble here. + */ void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) {