[PATCH 5/5] powerpc/mm: Move hash specific pte bits to be top bits of RPN
From: Aneesh Kumar K.V <hidden>
Date: 2017-02-21 08:19:49
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
We don't support the full 57 bits of physical address and hence can overload the top bits of RPN as hash specific pte bits. Signed-off-by: Aneesh Kumar K.V <redacted> --- arch/powerpc/include/asm/book3s/64/hash.h | 18 ++++++------------ arch/powerpc/include/asm/book3s/64/pgtable.h | 19 ++++++++++++++++--- 2 files changed, 22 insertions(+), 15 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index af3c88624d3a..205c04df9cf3 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h@@ -6,20 +6,14 @@ * Common bits between 4K and 64K pages in a linux-style PTE. * Additional bits may be defined in pgtable-hash64-*.h * - * Note: We only support user read/write permissions. Supervisor always - * have full read/write to pages above PAGE_OFFSET (pages below that - * always use the user access permissions). - * - * We could create separate kernel read-only if we used the 3 PP bits - * combinations that newer processors provide but we currently don't. */ -#define H_PAGE_BUSY _RPAGE_SW1 /* software: PTE & hash are busy */ +#define H_PAGE_BUSY _RPAGE_RPN45 /* software: PTE & hash are busy */ #define H_PTE_NONE_MASK _PAGE_HPTEFLAGS -#define H_PAGE_F_GIX_SHIFT 57 -/* (7ul << 57) HPTE index within HPTEG */ -#define H_PAGE_F_GIX (_RPAGE_RSV2 | _RPAGE_RSV3 | _RPAGE_RSV4) -#define H_PAGE_F_SECOND _RPAGE_RSV1 /* HPTE is in 2ndary HPTEG */ -#define H_PAGE_HASHPTE _RPAGE_SW0 /* PTE has associated HPTE */ +#define H_PAGE_F_GIX_SHIFT 53 +/* (7ul << 53) HPTE index within HPTEG */ +#define H_PAGE_F_GIX (_RPAGE_RPN44 | _RPAGE_RPN43 | _RPAGE_RPN42) +#define H_PAGE_F_SECOND _RPAGE_RPN41 /* HPTE is in 2ndary HPTEG */ +#define H_PAGE_HASHPTE _RPAGE_RPN40 /* PTE has associated HPTE */ /* * Max physical address bit we will use for now. *
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 0ea69c91520b..3fd9e46e44c5 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h@@ -30,16 +30,29 @@ #define _RPAGE_RSV2 0x0800000000000000UL #define _RPAGE_RSV3 0x0400000000000000UL #define _RPAGE_RSV4 0x0200000000000000UL + +#define _PAGE_PTE 0x4000000000000000UL /* distinguishes PTEs from pointers */ +#define _PAGE_PRESENT 0x8000000000000000UL /* pte contains a translation */ + +/* + * Top and bottom bits of RPN which can be used by hash + * translation mode, because we expect them to be zero + * otherwise. + */ #define _RPAGE_RPN0 0x01000 #define _RPAGE_RPN1 0x02000 +#define _RPAGE_RPN45 0x0100000000000000UL +#define _RPAGE_RPN44 0x0080000000000000UL +#define _RPAGE_RPN43 0x0040000000000000UL +#define _RPAGE_RPN42 0x0020000000000000UL +#define _RPAGE_RPN41 0x0010000000000000UL +#define _RPAGE_RPN40 0x0008000000000000UL + /* Max physicall address bit as per radix table */ #define _RPAGE_PA_MAX 57 #define _PAGE_SOFT_DIRTY _RPAGE_SW3 /* software: software dirty tracking */ #define _PAGE_SPECIAL _RPAGE_SW2 /* software: special page */ - -#define _PAGE_PTE 0x4000000000000000UL /* distinguishes PTEs from pointers */ -#define _PAGE_PRESENT 0x8000000000000000UL /* pte contains a translation */ /* * Drivers request for cache inhibited pte mapping using _PAGE_NO_CACHE * Instead of fixing all of them, add an alternate define which
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2.7.4