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powerpc/mm: add pte helpers to query and change pte flags

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In order to avoid using generic _PAGE_XXX flags in powerpc
core functions, define helpers for all needed flags:
- pte_mkuser() and pte_mkprivileged() to set/unset and/or
unset/set _PAGE_USER and/or _PAGE_PRIVILEGED
- pte_hashpte() to check if _PAGE_HASHPTE is set.
- pte_ci() check if cache is inhibited (already existing on book3s/64)
- pte_exprotect() to protect against execution
- pte_exec() and pte_mkexec() to query and set page execution
- pte_mkpte() to set _PAGE_PTE flag.
- pte_hw_valid() to check _PAGE_PRESENT since pte_present does
something different on book3s/64.

On book3s/32 there is no exec protection, so pte_mkexec() and
pte_exprotect() are nops and pte_exec() returns always true.

Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Christophe Leroy
2018-10-09 13:51:52 +00:00
committed by Michael Ellerman
parent aa9cd505e3
commit daba790242
5 changed files with 114 additions and 0 deletions
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28
arch/powerpc/include/asm/nohash/pgtable.h
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@@ -19,6 +19,9 @@ static inline int pte_read(pte_t pte) { return 1; }
static inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; }
static inline int pte_none(pte_t pte) { return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; }
static inline bool pte_hashpte(pte_t pte) { return false; }
static inline bool pte_ci(pte_t pte) { return pte_val(pte) & _PAGE_NO_CACHE; }
static inline bool pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_EXEC; }
static inline pgprot_t pte_pgprot(pte_t pte) { return __pgprot(pte_val(pte) & PAGE_PROT_BITS); }
#ifdef CONFIG_NUMA_BALANCING
@@ -44,6 +47,11 @@ static inline int pte_present(pte_t pte)
return pte_val(pte) & _PAGE_PRESENT;
}
static inline bool pte_hw_valid(pte_t pte)
{
return pte_val(pte) & _PAGE_PRESENT;
}
/*
* We only find page table entry in the last level
* Hence no need for other accessors
@@ -77,6 +85,11 @@ static inline unsigned long pte_pfn(pte_t pte) {
return pte_val(pte) >> PTE_RPN_SHIFT; }
/* Generic modifiers for PTE bits */
static inline pte_t pte_exprotect(pte_t pte)
{
return __pte(pte_val(pte) & ~_PAGE_EXEC);
}
static inline pte_t pte_mkclean(pte_t pte)
{
return __pte(pte_val(pte) & ~(_PAGE_DIRTY | _PAGE_HWWRITE));
@@ -87,6 +100,11 @@ static inline pte_t pte_mkold(pte_t pte)
return __pte(pte_val(pte) & ~_PAGE_ACCESSED);
}
static inline pte_t pte_mkpte(pte_t pte)
{
return pte;
}
static inline pte_t pte_mkspecial(pte_t pte)
{
return __pte(pte_val(pte) | _PAGE_SPECIAL);
@@ -97,6 +115,16 @@ static inline pte_t pte_mkhuge(pte_t pte)
return __pte(pte_val(pte) | _PAGE_HUGE);
}
static inline pte_t pte_mkprivileged(pte_t pte)
{
return __pte((pte_val(pte) & ~_PAGE_USER) | _PAGE_PRIVILEGED);
}
static inline pte_t pte_mkuser(pte_t pte)
{
return __pte((pte_val(pte) & ~_PAGE_PRIVILEGED) | _PAGE_USER);
}
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));