[RFC PATCH 3/4] mm: Export functions for writing MM Filesystems

[Bijan Tabatabai <bijan311@xxxxxxxxx>]

This patch exports memory management functions that are useful to memory
managers, so that they can be used in memory management filesystems created
in kernel modules.

Signed-off-by: Bijan Tabatabai <btabatabai@xxxxxxxx>
---
 arch/x86/include/asm/tlbflush.h | 2 --
 arch/x86/mm/tlb.c               | 1 +
 mm/filemap.c                    | 2 ++
 mm/memory.c                     | 1 +
 mm/mmap.c                       | 2 ++
 mm/pgtable-generic.c            | 1 +
 mm/rmap.c                       | 2 ++
 7 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 25726893c6f4..9877176d396f 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -57,7 +57,6 @@ static inline void cr4_clear_bits(unsigned long mask)
 	local_irq_restore(flags);
 }
 
-#ifndef MODULE
 /*
  * 6 because 6 should be plenty and struct tlb_state will fit in two cache
  * lines.
@@ -417,7 +416,6 @@ static inline void set_tlbstate_lam_mode(struct mm_struct *mm)
 {
 }
 #endif
-#endif /* !MODULE */
 
 static inline void __native_tlb_flush_global(unsigned long cr4)
 {
diff --git a/arch/x86/mm/tlb.c b/arch/x86/mm/tlb.c
index 44ac64f3a047..f054cee7bc7c 100644
--- a/arch/x86/mm/tlb.c
+++ b/arch/x86/mm/tlb.c
@@ -1036,6 +1036,7 @@ void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
 	put_cpu();
 	mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end);
 }
+EXPORT_SYMBOL_GPL(flush_tlb_mm_range);
 
 
 static void do_flush_tlb_all(void *info)
diff --git a/mm/filemap.c b/mm/filemap.c
index 657bcd887fdb..8532ddd37e7f 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -269,6 +269,7 @@ void filemap_remove_folio(struct folio *folio)
 
 	filemap_free_folio(mapping, folio);
 }
+EXPORT_SYMBOL_GPL(filemap_remove_folio);
 
 /*
  * page_cache_delete_batch - delete several folios from page cache
@@ -955,6 +956,7 @@ noinline int __filemap_add_folio(struct address_space *mapping,
 	return xas_error(&xas);
 }
 ALLOW_ERROR_INJECTION(__filemap_add_folio, ERRNO);
+EXPORT_SYMBOL_GPL(__filemap_add_folio);
 
 int filemap_add_folio(struct address_space *mapping, struct folio *folio,
 				pgoff_t index, gfp_t gfp)
diff --git a/mm/memory.c b/mm/memory.c
index fa2fe3ee0867..23e74a0397fa 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -448,6 +448,7 @@ int __pte_alloc(struct mm_struct *mm, pmd_t *pmd)
 		pte_free(mm, new);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(__pte_alloc);
 
 int __pte_alloc_kernel(pmd_t *pmd)
 {
diff --git a/mm/mmap.c b/mm/mmap.c
index d684d8bd218b..1090ef982929 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1780,6 +1780,7 @@ generic_get_unmapped_area(struct file *filp, unsigned long addr,
 	info.high_limit = mmap_end;
 	return vm_unmapped_area(&info);
 }
+EXPORT_SYMBOL_GPL(generic_get_unmapped_area);
 
 #ifndef HAVE_ARCH_UNMAPPED_AREA
 unsigned long
@@ -1844,6 +1845,7 @@ generic_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 
 	return addr;
 }
+EXPORT_SYMBOL_GPL(generic_get_unmapped_area_topdown);
 
 #ifndef HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 unsigned long
diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index a78a4adf711a..1a3b4a86b005 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -304,6 +304,7 @@ pte_t *__pte_offset_map(pmd_t *pmd, unsigned long addr, pmd_t *pmdvalp)
 	rcu_read_unlock();
 	return NULL;
 }
+EXPORT_SYMBOL_GPL(__pte_offset_map);
 
 pte_t *pte_offset_map_nolock(struct mm_struct *mm, pmd_t *pmd,
 			     unsigned long addr, spinlock_t **ptlp)
diff --git a/mm/rmap.c b/mm/rmap.c
index e8fc5ecb59b2..fdade910cc95 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1468,6 +1468,7 @@ void folio_add_file_rmap_ptes(struct folio *folio, struct page *page,
 {
 	__folio_add_file_rmap(folio, page, nr_pages, vma, RMAP_LEVEL_PTE);
 }
+EXPORT_SYMBOL_GPL(folio_add_file_rmap_ptes);
 
 /**
  * folio_add_file_rmap_pmd - add a PMD mapping to a page range of a folio
@@ -1594,6 +1595,7 @@ void folio_remove_rmap_ptes(struct folio *folio, struct page *page,
 {
 	__folio_remove_rmap(folio, page, nr_pages, vma, RMAP_LEVEL_PTE);
 }
+EXPORT_SYMBOL_GPL(folio_remove_rmap_ptes);
 
 /**
  * folio_remove_rmap_pmd - remove a PMD mapping from a page range of a folio
-- 
2.34.1