[RFC PATCH v4 11/16] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits)

[Christophe Leroy]

At the time being when CONFIG_PTE_64BIT is selected, PTE entries are
64 bits but PGD entries are still 32 bits.

In order to allow leaf PMD entries, switch the PGD to 64 bits entries.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
 arch/powerpc/include/asm/pgtable-types.h |  4 ++++
 arch/powerpc/kernel/head_85xx.S          | 10 ++++++----
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/pgtable-types.h b/arch/powerpc/include/asm/pgtable-types.h
index 082c85cc09b1..db965d98e0ae 100644
--- a/arch/powerpc/include/asm/pgtable-types.h
+++ b/arch/powerpc/include/asm/pgtable-types.h
@@ -49,7 +49,11 @@ static inline unsigned long pud_val(pud_t x)
 #endif /* CONFIG_PPC64 */
 
 /* PGD level */
+#if defined(CONFIG_PPC_E500) && defined(CONFIG_PTE_64BIT)
+typedef struct { unsigned long long pgd; } pgd_t;
+#else
 typedef struct { unsigned long pgd; } pgd_t;
+#endif
 #define __pgd(x)	((pgd_t) { (x) })
 static inline unsigned long pgd_val(pgd_t x)
 {
diff --git a/arch/powerpc/kernel/head_85xx.S b/arch/powerpc/kernel/head_85xx.S
index 39724ff5ae1f..a305244afc9f 100644
--- a/arch/powerpc/kernel/head_85xx.S
+++ b/arch/powerpc/kernel/head_85xx.S
@@ -307,8 +307,9 @@ set_ivor:
 #ifdef CONFIG_PTE_64BIT
 #ifdef CONFIG_HUGETLB_PAGE
 #define FIND_PTE	\
-	rlwinm	r12, r10, 13, 19, 29;	/* Compute pgdir/pmd offset */	\
-	lwzx	r11, r12, r11;		/* Get pgd/pmd entry */		\
+	rlwinm	r12, r10, 14, 18, 28;	/* Compute pgdir/pmd offset */	\
+	add	r12, r11, r12;						\
+	lwz	r11, 4(r12);		/* Get pgd/pmd entry */		\
 	rlwinm.	r12, r11, 0, 0, 20;	/* Extract pt base address */	\
 	blt	1000f;			/* Normal non-huge page */	\
 	beq	2f;			/* Bail if no table */		\
@@ -321,8 +322,9 @@ set_ivor:
 1001:	lwz	r11, 4(r12);		/* Get pte entry */
 #else
 #define FIND_PTE	\
-	rlwinm	r12, r10, 13, 19, 29;	/* Compute pgdir/pmd offset */	\
-	lwzx	r11, r12, r11;		/* Get pgd/pmd entry */		\
+	rlwinm	r12, r10, 14, 18, 28;	/* Compute pgdir/pmd offset */	\
+	add	r12, r11, r12;						\
+	lwz	r11, 4(r12);		/* Get pgd/pmd entry */		\
 	rlwinm.	r12, r11, 0, 0, 20;	/* Extract pt base address */	\
 	beq	2f;			/* Bail if no table */		\
 	rlwimi	r12, r10, 23, 20, 28;	/* Compute pte address */	\
-- 
2.44.0