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From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Andrew Morton <akpm@linux-foundation.org>,
	Jason Gunthorpe <jgg@nvidia.com>,
	Peter Xu <peterx@redhat.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>,
	linux-kernel@vger.kernel.org,
	linux-mm@kvack.org,
	linuxppc-dev@lists.ozlabs.org
Subject: [RFC PATCH 5/8] powerpc/mm: Allow hugepages without hugepd
Date: Mon, 25 Mar 2024 15:55:58 +0100
Message-ID: <69591a2e4fd72c1dd09eb8e0b2e7f1256fd32304.1711377230.git.christophe.leroy@csgroup.eu>
In-Reply-To: <cover.1711377230.git.christophe.leroy@csgroup.eu>
References: <cover.1711377230.git.christophe.leroy@csgroup.eu>
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In preparation of implementing huge pages on powerpc 8xx
without hugepd, enclose hugepd related code inside an
ifdef CONFIG_ARCH_HAS_HUGEPD

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/hugetlb.h        |  2 ++
 arch/powerpc/include/asm/nohash/pgtable.h |  8 +++++---
 arch/powerpc/mm/hugetlbpage.c             | 10 ++++++++++
 arch/powerpc/mm/pgtable.c                 |  2 ++
 4 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index ea71f7245a63..a05657e5701b 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -30,10 +30,12 @@ static inline int is_hugepage_only_range(struct mm_struct *mm,
 }
 #define is_hugepage_only_range is_hugepage_only_range
 
+#ifdef CONFIG_ARCH_HAS_HUGEPD
 #define __HAVE_ARCH_HUGETLB_FREE_PGD_RANGE
 void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
 			    unsigned long end, unsigned long floor,
 			    unsigned long ceiling);
+#endif
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index 427db14292c9..ac3353f7f2ac 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -340,7 +340,7 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
 
 #define pgprot_writecombine pgprot_noncached_wc
 
-#ifdef CONFIG_HUGETLB_PAGE
+#ifdef CONFIG_ARCH_HAS_HUGEPD
 static inline int hugepd_ok(hugepd_t hpd)
 {
 #ifdef CONFIG_PPC_8xx
@@ -351,6 +351,10 @@ static inline int hugepd_ok(hugepd_t hpd)
 #endif
 }
 
+#define is_hugepd(hpd)		(hugepd_ok(hpd))
+#endif
+
+#ifdef CONFIG_HUGETLB_PAGE
 static inline int pmd_huge(pmd_t pmd)
 {
 	return 0;
@@ -360,8 +364,6 @@ static inline int pud_huge(pud_t pud)
 {
 	return 0;
 }
-
-#define is_hugepd(hpd)		(hugepd_ok(hpd))
 #endif
 
 int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot);
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 66ac56b26007..db73ad845a2a 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -42,6 +42,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, unsigned long s
 	return __find_linux_pte(mm->pgd, addr, NULL, NULL);
 }
 
+#ifdef CONFIG_ARCH_HAS_HUGEPD
 static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
 			   unsigned long address, unsigned int pdshift,
 			   unsigned int pshift, spinlock_t *ptl)
@@ -193,6 +194,13 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
 
 	return hugepte_offset(*hpdp, addr, pdshift);
 }
+#else
+pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
+		      unsigned long addr, unsigned long sz)
+{
+	return pte_alloc_huge(mm, pmd_off(mm, addr), addr, sz);
+}
+#endif
 
 #ifdef CONFIG_PPC_BOOK3S_64
 /*
@@ -248,6 +256,7 @@ int __init alloc_bootmem_huge_page(struct hstate *h, int nid)
 	return __alloc_bootmem_huge_page(h, nid);
 }
 
+#ifdef CONFIG_ARCH_HAS_HUGEPD
 #ifndef CONFIG_PPC_BOOK3S_64
 #define HUGEPD_FREELIST_SIZE \
 	((PAGE_SIZE - sizeof(struct hugepd_freelist)) / sizeof(pte_t))
@@ -505,6 +514,7 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 		}
 	} while (addr = next, addr != end);
 }
+#endif
 
 bool __init arch_hugetlb_valid_size(unsigned long size)
 {
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 9e7ba9c3851f..acdf64c9b93e 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -487,8 +487,10 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
 	if (!hpdp)
 		return NULL;
 
+#ifdef CONFIG_ARCH_HAS_HUGEPD
 	ret_pte = hugepte_offset(*hpdp, ea, pdshift);
 	pdshift = hugepd_shift(*hpdp);
+#endif
 out:
 	if (hpage_shift)
 		*hpage_shift = pdshift;
-- 
2.43.0