powerpc/book3s64/mm: enable transparent pud hugepage

This is enabled only with radix translation and 1G hugepage size.  This
will be used with devdax device memory with a namespace alignment of 1G.

Anon transparent hugepage is not supported even though we do have helpers
checking pud_trans_huge().  We should never find that return true.  The
only expected pte bit combination is _PAGE_PTE | _PAGE_DEVMAP.

Some of the helpers are never expected to get called on hash translation
and hence is marked to call BUG() in such a case.

Link: https://lkml.kernel.org/r/20230724190759.483013-10-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h
index 686001eda936..2ef92f36340f 100644
--- a/arch/powerpc/include/asm/book3s/64/radix.h
+++ b/arch/powerpc/include/asm/book3s/64/radix.h
@@ -250,6 +250,10 @@ static inline int radix__pud_bad(pud_t pud)
 	return !!(pud_val(pud) & RADIX_PUD_BAD_BITS);
 }
 
+static inline int radix__pud_same(pud_t pud_a, pud_t pud_b)
+{
+	return ((pud_raw(pud_a) ^ pud_raw(pud_b)) == 0);
+}
 
 static inline int radix__p4d_bad(p4d_t p4d)
 {
@@ -268,9 +272,22 @@ static inline pmd_t radix__pmd_mkhuge(pmd_t pmd)
 	return __pmd(pmd_val(pmd) | _PAGE_PTE);
 }
 
+static inline int radix__pud_trans_huge(pud_t pud)
+{
+	return (pud_val(pud) & (_PAGE_PTE | _PAGE_DEVMAP)) == _PAGE_PTE;
+}
+
+static inline pud_t radix__pud_mkhuge(pud_t pud)
+{
+	return __pud(pud_val(pud) | _PAGE_PTE);
+}
+
 extern unsigned long radix__pmd_hugepage_update(struct mm_struct *mm, unsigned long addr,
 					  pmd_t *pmdp, unsigned long clr,
 					  unsigned long set);
+extern unsigned long radix__pud_hugepage_update(struct mm_struct *mm, unsigned long addr,
+						pud_t *pudp, unsigned long clr,
+						unsigned long set);
 extern pmd_t radix__pmdp_collapse_flush(struct vm_area_struct *vma,
 				  unsigned long address, pmd_t *pmdp);
 extern void radix__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
@@ -278,6 +295,9 @@ extern void radix__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
 extern pgtable_t radix__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
 extern pmd_t radix__pmdp_huge_get_and_clear(struct mm_struct *mm,
 				      unsigned long addr, pmd_t *pmdp);
+pud_t radix__pudp_huge_get_and_clear(struct mm_struct *mm,
+				     unsigned long addr, pud_t *pudp);
+
 static inline int radix__has_transparent_hugepage(void)
 {
 	/* For radix 2M at PMD level means thp */
@@ -285,6 +305,14 @@ static inline int radix__has_transparent_hugepage(void)
 		return 1;
 	return 0;
 }
+
+static inline int radix__has_transparent_pud_hugepage(void)
+{
+	/* For radix 1G at PUD level means pud hugepage support */
+	if (mmu_psize_defs[MMU_PAGE_1G].shift == PUD_SHIFT)
+		return 1;
+	return 0;
+}
 #endif
 
 static inline pmd_t radix__pmd_mkdevmap(pmd_t pmd)
@@ -292,9 +320,17 @@ static inline pmd_t radix__pmd_mkdevmap(pmd_t pmd)
 	return __pmd(pmd_val(pmd) | (_PAGE_PTE | _PAGE_DEVMAP));
 }
 
+static inline pud_t radix__pud_mkdevmap(pud_t pud)
+{
+	return __pud(pud_val(pud) | (_PAGE_PTE | _PAGE_DEVMAP));
+}
+
+struct vmem_altmap;
 extern int __meminit radix__vmemmap_create_mapping(unsigned long start,
 					     unsigned long page_size,
 					     unsigned long phys);
+int __meminit radix__vmemmap_populate(unsigned long start, unsigned long end,
+				      int node, struct vmem_altmap *altmap);
 extern void radix__vmemmap_remove_mapping(unsigned long start,
 				    unsigned long page_size);