[PATCH v2 33/69] mm/sparse: Remove SPARSEMEM_VMEMMAP_PREINIT

[Muchun Song <songmuchun@bytedance.com>]

SPARSEMEM_VMEMMAP_PREINIT was only there to support HugeTLB's early
vmemmap optimization setup.

Now that HugeTLB bootmem vmemmap optimization uses the common
section-based sparse-vmemmap path, sparsemem no longer needs a separate
pre-initialization mechanism.

Remove the Kconfig symbols, section flag, and empty sparse-vmemmap early
hook, and always initialize present sections through the normal sparse
setup path.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 arch/x86/Kconfig       |  1 -
 fs/Kconfig             |  1 -
 include/linux/mmzone.h | 25 -------------------------
 mm/Kconfig             |  5 -----
 mm/sparse-vmemmap.c    | 13 -------------
 mm/sparse.c            | 23 ++++++++---------------
 6 files changed, 8 insertions(+), 60 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index f24810015234..ed2aa0e4c472 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -148,7 +148,6 @@ config X86
 	select ARCH_WANT_LD_ORPHAN_WARN
 	select ARCH_WANT_OPTIMIZE_DAX_VMEMMAP	if X86_64
 	select ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP	if X86_64
-	select ARCH_WANT_HUGETLB_VMEMMAP_PREINIT if X86_64
 	select ARCH_WANTS_THP_SWAP		if X86_64
 	select ARCH_HAS_PARANOID_L1D_FLUSH
 	select ARCH_WANT_IRQS_OFF_ACTIVATE_MM
diff --git a/fs/Kconfig b/fs/Kconfig
index cf6ae64776e6..ccb9dd480523 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -278,7 +278,6 @@ config HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 	def_bool HUGETLB_PAGE
 	depends on ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
 	depends on SPARSEMEM_VMEMMAP
-	select SPARSEMEM_VMEMMAP_PREINIT if ARCH_WANT_HUGETLB_VMEMMAP_PREINIT
 
 config HUGETLB_PMD_PAGE_TABLE_SHARING
 	def_bool HUGETLB_PAGE
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index d6a5dd042c25..b9baef8cca91 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -2092,9 +2092,6 @@ enum {
 	SECTION_IS_EARLY_BIT,
 #ifdef CONFIG_ZONE_DEVICE
 	SECTION_TAINT_ZONE_DEVICE_BIT,
-#endif
-#ifdef CONFIG_SPARSEMEM_VMEMMAP_PREINIT
-	SECTION_IS_VMEMMAP_PREINIT_BIT,
 #endif
 	SECTION_MAP_LAST_BIT,
 };
@@ -2106,9 +2103,6 @@ enum {
 #ifdef CONFIG_ZONE_DEVICE
 #define SECTION_TAINT_ZONE_DEVICE	BIT(SECTION_TAINT_ZONE_DEVICE_BIT)
 #endif
-#ifdef CONFIG_SPARSEMEM_VMEMMAP_PREINIT
-#define SECTION_IS_VMEMMAP_PREINIT	BIT(SECTION_IS_VMEMMAP_PREINIT_BIT)
-#endif
 #define SECTION_MAP_MASK		(~(BIT(SECTION_MAP_LAST_BIT) - 1))
 #define SECTION_NID_SHIFT		SECTION_MAP_LAST_BIT
 
@@ -2163,24 +2157,6 @@ static inline int online_device_section(const struct mem_section *section)
 }
 #endif
 
-#ifdef CONFIG_SPARSEMEM_VMEMMAP_PREINIT
-static inline int preinited_vmemmap_section(const struct mem_section *section)
-{
-	return (section &&
-		(section->section_mem_map & SECTION_IS_VMEMMAP_PREINIT));
-}
-
-void sparse_vmemmap_init_nid_early(int nid);
-#else
-static inline int preinited_vmemmap_section(const struct mem_section *section)
-{
-	return 0;
-}
-static inline void sparse_vmemmap_init_nid_early(int nid)
-{
-}
-#endif
-
 static inline int online_section_nr(unsigned long nr)
 {
 	return online_section(__nr_to_section(nr));
@@ -2427,7 +2403,6 @@ static inline unsigned long next_present_section_nr(unsigned long section_nr)
 #endif
 
 #else
-#define sparse_vmemmap_init_nid_early(_nid) do {} while (0)
 #define pfn_in_present_section pfn_valid
 static inline void section_set_order_range(unsigned long pfn, unsigned long nr_pages,
 					   unsigned int order)
diff --git a/mm/Kconfig b/mm/Kconfig
index bb0202cf8b15..c26d2d2050d5 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -410,8 +410,6 @@ config SPARSEMEM_VMEMMAP
 	  pfn_to_page and page_to_pfn operations.  This is the most
 	  efficient option when sufficient kernel resources are available.
 
-config SPARSEMEM_VMEMMAP_PREINIT
-	bool
 #
 # Select this config option from the architecture Kconfig, if it is preferred
 # to enable the feature of HugeTLB/dev_dax vmemmap optimization.
@@ -422,9 +420,6 @@ config ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
 config ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP
 	bool
 
-config ARCH_WANT_HUGETLB_VMEMMAP_PREINIT
-	bool
-
 config HAVE_MEMBLOCK_PHYS_MAP
 	bool
 
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index f1c3b2d0f23c..dde4486195ad 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -548,19 +548,6 @@ struct page * __meminit __populate_section_memmap(unsigned long pfn,
 	return pfn_to_page(pfn);
 }
 
-#ifdef CONFIG_SPARSEMEM_VMEMMAP_PREINIT
-/*
- * This is called just before initializing sections for a NUMA node.
- * Any special initialization that needs to be done before the
- * generic initialization can be done from here. Sections that
- * are initialized in hooks called from here will be skipped by
- * the generic initialization.
- */
-void __init sparse_vmemmap_init_nid_early(int nid)
-{
-}
-#endif
-
 static void subsection_mask_set(unsigned long *map, unsigned long pfn,
 		unsigned long nr_pages)
 {
diff --git a/mm/sparse.c b/mm/sparse.c
index 47349f6f463f..eab37504819d 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -316,27 +316,20 @@ static void __init sparse_init_nid(int nid, unsigned long pnum_begin,
 	if (sparse_usage_init(nid, map_count))
 		panic("Failed to allocate usemap for node %d\n", nid);
 
-	sparse_vmemmap_init_nid_early(nid);
-
 	for_each_present_section_nr(pnum_begin, pnum) {
-		struct mem_section *ms;
 		unsigned long pfn = section_nr_to_pfn(pnum);
+		struct page *map;
 
 		if (pnum >= pnum_end)
 			break;
 
-		ms = __nr_to_section(pnum);
-		if (!preinited_vmemmap_section(ms)) {
-			struct page *map;
-
-			map = __populate_section_memmap(pfn, PAGES_PER_SECTION,
-							nid, NULL, NULL);
-			if (!map)
-				panic("Failed to allocate memmap for section %lu\n", pnum);
-			memmap_boot_pages_add(section_nr_vmemmap_pages(pfn, PAGES_PER_SECTION,
-								       NULL, NULL));
-			sparse_init_early_section(nid, map, pnum, 0);
-		}
+		map = __populate_section_memmap(pfn, PAGES_PER_SECTION,
+						nid, NULL, NULL);
+		if (!map)
+			panic("Failed to allocate memmap for section %lu\n", pnum);
+		memmap_boot_pages_add(section_nr_vmemmap_pages(pfn, PAGES_PER_SECTION,
+							       NULL, NULL));
+		sparse_init_early_section(nid, map, pnum, 0);
 	}
 	sparse_usage_fini();
 }
-- 
2.54.0