From: David Hildenbrand <david@xxxxxxxxxx> Subject: x86: remove memory hotplug support on X86_32 CONFIG_MEMORY_HOTPLUG was marked BROKEN over one year and we just restricted it to 64 bit. Let's remove the unused x86 32bit implementation and simplify the Kconfig. Link: https://lkml.kernel.org/r/20210929143600.49379-7-david@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> Cc: Alex Shi <alexs@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Jason Wang <jasowang@xxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: "Michael S. Tsirkin" <mst@xxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- arch/x86/Kconfig | 6 +++--- arch/x86/mm/init_32.c | 31 ------------------------------- 2 files changed, 3 insertions(+), 34 deletions(-) --- a/arch/x86/Kconfig~x86-remove-memory-hotplug-support-on-x86_32 +++ a/arch/x86/Kconfig @@ -62,7 +62,7 @@ config X86 select ARCH_32BIT_OFF_T if X86_32 select ARCH_CLOCKSOURCE_INIT select ARCH_ENABLE_HUGEPAGE_MIGRATION if X86_64 && HUGETLB_PAGE && MIGRATION - select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 || (X86_32 && HIGHMEM) + select ARCH_ENABLE_MEMORY_HOTPLUG if X86_64 select ARCH_ENABLE_MEMORY_HOTREMOVE if MEMORY_HOTPLUG select ARCH_ENABLE_SPLIT_PMD_PTLOCK if (PGTABLE_LEVELS > 2) && (X86_64 || X86_PAE) select ARCH_ENABLE_THP_MIGRATION if X86_64 && TRANSPARENT_HUGEPAGE @@ -1614,7 +1614,7 @@ config ARCH_SELECT_MEMORY_MODEL config ARCH_MEMORY_PROBE bool "Enable sysfs memory/probe interface" - depends on X86_64 && MEMORY_HOTPLUG + depends on MEMORY_HOTPLUG help This option enables a sysfs memory/probe interface for testing. See Documentation/admin-guide/mm/memory-hotplug.rst for more information. @@ -2394,7 +2394,7 @@ endmenu config ARCH_HAS_ADD_PAGES def_bool y - depends on X86_64 && ARCH_ENABLE_MEMORY_HOTPLUG + depends on ARCH_ENABLE_MEMORY_HOTPLUG config ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE def_bool y --- a/arch/x86/mm/init_32.c~x86-remove-memory-hotplug-support-on-x86_32 +++ a/arch/x86/mm/init_32.c @@ -779,37 +779,6 @@ void __init mem_init(void) test_wp_bit(); } -#ifdef CONFIG_MEMORY_HOTPLUG -int arch_add_memory(int nid, u64 start, u64 size, - struct mhp_params *params) -{ - unsigned long start_pfn = start >> PAGE_SHIFT; - unsigned long nr_pages = size >> PAGE_SHIFT; - int ret; - - /* - * The page tables were already mapped at boot so if the caller - * requests a different mapping type then we must change all the - * pages with __set_memory_prot(). - */ - if (params->pgprot.pgprot != PAGE_KERNEL.pgprot) { - ret = __set_memory_prot(start, nr_pages, params->pgprot); - if (ret) - return ret; - } - - return __add_pages(nid, start_pfn, nr_pages, params); -} - -void arch_remove_memory(u64 start, u64 size, struct vmem_altmap *altmap) -{ - unsigned long start_pfn = start >> PAGE_SHIFT; - unsigned long nr_pages = size >> PAGE_SHIFT; - - __remove_pages(start_pfn, nr_pages, altmap); -} -#endif - int kernel_set_to_readonly __read_mostly; static void mark_nxdata_nx(void) _