releases/6.17.3/powerpc-603-really-copy-kernel-pgd-entries-into-all-.patch

From 738f2169e016009875c940581adb0c99219b84e9 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Thu, 21 Aug 2025 08:30:18 +0200
Subject: powerpc/603: Really copy kernel PGD entries into all PGDIRs

From: Christophe Leroy <christophe.leroy@csgroup.eu>

[ Upstream commit f2863371f017eb03c230addc253783fa4c7e90f5 ]

Commit 82ef440f9a38 ("powerpc/603: Copy kernel PGD entries into all
PGDIRs and preallocate execmem page tables") was supposed to extend
to powerpc 603 the copy of kernel PGD entries into all PGDIRs
implemented in a previous patch on the 8xx. But 603 is book3s/32 and
uses a duplicate of pgd_alloc() defined in another header.

So really do the copy at the correct place for the 603.

Fixes: 82ef440f9a38 ("powerpc/603: Copy kernel PGD entries into all PGDIRs and preallocate execmem page tables")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/752ab7514cae089a2dd7cc0f3d5e35849f76adb9.1755757797.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/include/asm/book3s/32/pgalloc.h | 10 ++++++++--
 arch/powerpc/include/asm/nohash/pgalloc.h    |  2 +-
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h b/arch/powerpc/include/asm/book3s/32/pgalloc.h
index dd4eb30631758..f4390704d5ba2 100644
--- a/arch/powerpc/include/asm/book3s/32/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h
@@ -7,8 +7,14 @@
 
 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 {
-	return kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE),
-			pgtable_gfp_flags(mm, GFP_KERNEL));
+	pgd_t *pgd = kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE),
+				      pgtable_gfp_flags(mm, GFP_KERNEL));
+
+#ifdef CONFIG_PPC_BOOK3S_603
+	memcpy(pgd + USER_PTRS_PER_PGD, swapper_pg_dir + USER_PTRS_PER_PGD,
+	       (MAX_PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
+#endif
+	return pgd;
 }
 
 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
diff --git a/arch/powerpc/include/asm/nohash/pgalloc.h b/arch/powerpc/include/asm/nohash/pgalloc.h
index bb5f3e8ea912d..4ef780b291bc3 100644
--- a/arch/powerpc/include/asm/nohash/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/pgalloc.h
@@ -22,7 +22,7 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 	pgd_t *pgd = kmem_cache_alloc(PGT_CACHE(PGD_INDEX_SIZE),
 			pgtable_gfp_flags(mm, GFP_KERNEL));
 
-#if defined(CONFIG_PPC_8xx) || defined(CONFIG_PPC_BOOK3S_603)
+#ifdef CONFIG_PPC_8xx
 	memcpy(pgd + USER_PTRS_PER_PGD, swapper_pg_dir + USER_PTRS_PER_PGD,
 	       (MAX_PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
 #endif
-- 
2.51.0