[PATCH v1 6/6] x86: remove memory hotplug support on X86_32

David Hildenbrand
2021-09-29T14:37:46Z

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.

Signed-off-by: David Hildenbrand <david@redhat.com>
---
arch/x86/Kconfig | 6 +++---
arch/x86/mm/init_32.c | 31 -------------------------------
2 files changed, 3 insertions(+), 34 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index ab83c22d274e..85f4762429f1 100644
--- a/arch/x86/Kconfig
+++ b/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
@@ -1615,7 +1615,7 @@ 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.
@@ -2395,7 +2395,7 @@ 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
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index bd90b8fe81e4..5cd7ea6d645c 100644
--- a/arch/x86/mm/init_32.c
+++ b/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)
--
2.31.1