> -----Original Message----- > From: Benjamin Herrenschmidt [mailto:benh@xxxxxxxxxxxxxxxxxxx] > Sent: Saturday, August 03, 2013 9:54 AM > To: Bhushan Bharat-R65777 > Cc: Wood Scott-B07421; agraf@xxxxxxx; kvm-ppc@xxxxxxxxxxxxxxx; > kvm@xxxxxxxxxxxxxxx; linuxppc-dev@xxxxxxxxxxxxxxxx > Subject: Re: [PATCH 5/6 v2] kvm: powerpc: booke: Add linux pte lookup like > booke3s > > On Sat, 2013-08-03 at 02:58 +0000, Bhushan Bharat-R65777 wrote: > > One of the problem I saw was that if I put this code in > > asm/pgtable-32.h and asm/pgtable-64.h then pte_persent() and other > > friend function (on which this code depends) are defined in pgtable.h. > > And pgtable.h includes asm/pgtable-32.h and asm/pgtable-64.h before it > > defines pte_present() and friends functions. > > > > Ok I move wove this in asm/pgtable*.h, initially I fought with myself > > to take this code in pgtable* but finally end up doing here (got > > biased by book3s :)). > > Is there a reason why these routines can not be completely generic in pgtable.h > ? How about the generic function: diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h index d257d98..21daf28 100644 --- a/arch/powerpc/include/asm/pgtable-ppc64.h +++ b/arch/powerpc/include/asm/pgtable-ppc64.h @@ -221,6 +221,27 @@ static inline unsigned long pte_update(struct mm_struct *mm, return old; } +static inline unsigned long pte_read(pte_t *p) +{ +#ifdef PTE_ATOMIC_UPDATES + pte_t pte; + pte_t tmp; + __asm__ __volatile__ ( + "1: ldarx %0,0,%3\n" + " andi. %1,%0,%4\n" + " bne- 1b\n" + " ori %1,%0,%4\n" + " stdcx. %1,0,%3\n" + " bne- 1b" + : "=&r" (pte), "=&r" (tmp), "=m" (*p) + : "r" (p), "i" (_PAGE_BUSY) + : "cc"); + + return pte; +#else + return pte_val(*p); +#endif +#endif +} static inline int __ptep_test_and_clear_young(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index 690c8c2..dad712c 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -254,6 +254,45 @@ static inline pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, } #endif /* !CONFIG_HUGETLB_PAGE */ +static inline pte_t lookup_linux_pte(pgd_t *pgdir, unsigned long hva, + int writing, unsigned long *pte_sizep) +{ + pte_t *ptep; + pte_t pte; + unsigned long ps = *pte_sizep; + unsigned int shift; + + ptep = find_linux_pte_or_hugepte(pgdir, hva, &shift); + if (!ptep) + return __pte(0); + if (shift) + *pte_sizep = 1ul << shift; + else + *pte_sizep = PAGE_SIZE; + + if (ps > *pte_sizep) + return __pte(0); + + if (!pte_present(*ptep)) + return __pte(0); + +#ifdef CONFIG_PPC64 + /* Lock PTE (set _PAGE_BUSY) and read */ + pte = pte_read(ptep); +#else + pte = pte_val(*ptep); +#endif + if (pte_present(pte)) { + pte = pte_mkyoung(pte); + if (writing && pte_write(pte)) + pte = pte_mkdirty(pte); + } + + *ptep = __pte(pte); /* 64bit: Also unlock pte (clear _PAGE_BUSY) */ + + return pte; +} + #endif /* __ASSEMBLY__ */ #endif /* __KERNEL__ */ ��.n��������+%������w��{.n�����o�^n�r������&��z�ޗ�zf���h���~����������_��+v���)ߣ�
