Commit cba5d9b3 authored by Kiryl Shutsemau's avatar Kiryl Shutsemau Committed by Ingo Molnar
Browse files

x86/mm/64: Make SPARSEMEM_VMEMMAP the only memory model 



5-level paging only supports SPARSEMEM_VMEMMAP. CONFIG_X86_5LEVEL is
being phased out, making 5-level paging support mandatory.

Make CONFIG_SPARSEMEM_VMEMMAP mandatory for x86-64 and eliminate
any associated conditional statements.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarArd Biesheuvel <ardb@kernel.org>
Reviewed-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20250516123306.3812286-3-kirill.shutemov@linux.intel.com
parent 1bffe6f6

arch/x86/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -1467,7 +1467,6 @@ config X86_PAE 
config X86_5LEVEL

	bool "Enable 5-level page tables support"

	default y

	select SPARSEMEM_VMEMMAP

	depends on X86_64

	help

	  5-level paging enables access to larger address space:
@@ -1579,6 +1578,7 @@ config ARCH_SPARSEMEM_ENABLE 
	def_bool y

	select SPARSEMEM_STATIC if X86_32

	select SPARSEMEM_VMEMMAP_ENABLE if X86_64

	select SPARSEMEM_VMEMMAP if X86_64



config ARCH_SPARSEMEM_DEFAULT

	def_bool X86_64 || (NUMA && X86_32)

arch/x86/mm/init_64.c

+1 −8
Original line number Diff line number Diff line
@@ -833,7 +833,6 @@ void __init paging_init(void) 
	zone_sizes_init();

}



#ifdef CONFIG_SPARSEMEM_VMEMMAP

#define PAGE_UNUSED 0xFD



/*
@@ -932,7 +931,6 @@ static void __meminit vmemmap_use_new_sub_pmd(unsigned long start, unsigned long 
	if (!IS_ALIGNED(end, PMD_SIZE))

		unused_pmd_start = end;

}

#endif



/*

 * Memory hotplug specific functions
@@ -1152,16 +1150,13 @@ remove_pmd_table(pmd_t *pmd_start, unsigned long addr, unsigned long end, 
				pmd_clear(pmd);

				spin_unlock(&init_mm.page_table_lock);

				pages++;

			}

#ifdef CONFIG_SPARSEMEM_VMEMMAP

			else if (vmemmap_pmd_is_unused(addr, next)) {

			} else if (vmemmap_pmd_is_unused(addr, next)) {

					free_hugepage_table(pmd_page(*pmd),

							    altmap);

					spin_lock(&init_mm.page_table_lock);

					pmd_clear(pmd);

					spin_unlock(&init_mm.page_table_lock);

			}

#endif

			continue;

		}
@@ -1500,7 +1495,6 @@ unsigned long memory_block_size_bytes(void) 
	return memory_block_size_probed;

}



#ifdef CONFIG_SPARSEMEM_VMEMMAP

/*

 * Initialise the sparsemem vmemmap using huge-pages at the PMD level.

 */
@@ -1647,4 +1641,3 @@ void __meminit vmemmap_populate_print_last(void) 
		node_start = 0;

	}

}
 
#endif