From 351750331fc1580cdb60d2efef04238f5faa89fe Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Fri, 12 Jan 2018 13:45:29 +0100 Subject: [PATCH] powerpc/mm: Introduce _PAGE_NA Today, PAGE_NONE is defined as a page not having _PAGE_USER. In some circunstances, when the CPU supports it, it might be better to be able to flag a page with NO ACCESS. In a following patch, the 8xx will switch user access being flagged in the PMD, therefore it will not be possible anymore to use _PAGE_USER as a way to flag a page with no access. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/book3s/64/pgtable.h | 1 + arch/powerpc/include/asm/nohash/32/pgtable.h | 2 +- arch/powerpc/include/asm/pte-common.h | 7 +++++-- arch/powerpc/mm/dump_linuxpagetables.c | 18 +++++++++++------- 4 files changed, 18 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index 8e28febedac3..60a0d7fd82bc 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -14,6 +14,7 @@ */ #define _PAGE_BIT_SWAP_TYPE 0 +#define _PAGE_NA 0 #define _PAGE_RO 0 #define _PAGE_USER 0 diff --git a/arch/powerpc/include/asm/nohash/32/pgtable.h b/arch/powerpc/include/asm/nohash/32/pgtable.h index cc2bfec3aa3b..504a3c36ce5c 100644 --- a/arch/powerpc/include/asm/nohash/32/pgtable.h +++ b/arch/powerpc/include/asm/nohash/32/pgtable.h @@ -282,7 +282,7 @@ static inline void __ptep_set_access_flags(struct mm_struct *mm, { unsigned long set = pte_val(entry) & (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC); - unsigned long clr = ~pte_val(entry) & _PAGE_RO; + unsigned long clr = ~pte_val(entry) & (_PAGE_RO | _PAGE_NA); pte_update(ptep, clr, set); } diff --git a/arch/powerpc/include/asm/pte-common.h b/arch/powerpc/include/asm/pte-common.h index 0e6595a1b9d8..426a902816c5 100644 --- a/arch/powerpc/include/asm/pte-common.h +++ b/arch/powerpc/include/asm/pte-common.h @@ -50,6 +50,9 @@ #define _PAGE_USER 0 #endif #endif +#ifndef _PAGE_NA +#define _PAGE_NA 0 +#endif #ifndef _PMD_PRESENT_MASK #define _PMD_PRESENT_MASK _PMD_PRESENT @@ -122,7 +125,7 @@ static inline bool pte_user(pte_t pte) /* Mask of bits returned by pte_pgprot() */ #define PAGE_PROT_BITS (_PAGE_GUARDED | _PAGE_COHERENT | _PAGE_NO_CACHE | \ _PAGE_WRITETHRU | _PAGE_ENDIAN | _PAGE_4K_PFN | \ - _PAGE_USER | _PAGE_ACCESSED | _PAGE_RO | \ + _PAGE_USER | _PAGE_ACCESSED | _PAGE_RO | _PAGE_NA | \ _PAGE_PRIVILEGED | \ _PAGE_RW | _PAGE_HWWRITE | _PAGE_DIRTY | _PAGE_EXEC) @@ -150,7 +153,7 @@ static inline bool pte_user(pte_t pte) * * Note due to the way vm flags are laid out, the bits are XWR */ -#define PAGE_NONE __pgprot(_PAGE_BASE) +#define PAGE_NONE __pgprot(_PAGE_BASE | _PAGE_NA) #define PAGE_SHARED __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW) #define PAGE_SHARED_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | \ _PAGE_EXEC) diff --git a/arch/powerpc/mm/dump_linuxpagetables.c b/arch/powerpc/mm/dump_linuxpagetables.c index d87ab2cabaa6..876e2a3c79f2 100644 --- a/arch/powerpc/mm/dump_linuxpagetables.c +++ b/arch/powerpc/mm/dump_linuxpagetables.c @@ -117,16 +117,20 @@ static const struct flag_info flag_array[] = { .set = "user", .clear = " ", }, { -#if _PAGE_RO == 0 - .mask = _PAGE_RW, + .mask = _PAGE_RW | _PAGE_RO | _PAGE_NA, .val = _PAGE_RW, -#else - .mask = _PAGE_RO, - .val = 0, -#endif .set = "rw", - .clear = "ro", }, { + .mask = _PAGE_RW | _PAGE_RO | _PAGE_NA, + .val = _PAGE_RO, + .set = "ro", + }, { +#if _PAGE_NA != 0 + .mask = _PAGE_RW | _PAGE_RO | _PAGE_NA, + .val = _PAGE_RO, + .set = "na", + }, { +#endif .mask = _PAGE_EXEC, .val = _PAGE_EXEC, .set = " X ", -- 2.45.2