From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Sat, 4 May 2019 00:18:08 +0800 From: Guo Ren Subject: Re: [PATCH 05/15] csky: switch to generic version of pte allocation Message-ID: <20190503161808.GA11596@guoren-Inspiron-7460> References: <1556810922-20248-1-git-send-email-rppt@linux.ibm.com> <1556810922-20248-6-git-send-email-rppt@linux.ibm.com> <20190503160348.GA9526@guoren-Inspiron-7460> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190503160348.GA9526@guoren-Inspiron-7460> To: Mike Rapoport Cc: Michal Hocko , Catalin Marinas , Palmer Dabbelt , linux-mips@vger.kernel.org, Michael Ellerman , linux-hexagon@vger.kernel.org, linux-riscv@lists.infradead.org, linux-arch@vger.kernel.org, Richard Weinberger , Helge Deller , x86@kernel.org, Russell King , Matthew Wilcox , Geert Uytterhoeven , Matt Turner , Sam Creasey , Arnd Bergmann , linux-um@lists.infradead.org, linux-m68k@lists.linux-m68k.org, Greentime Hu , nios2-dev@lists.rocketboards.org, Guan Xuetao , linux-arm-kernel@lists.infradead.org, linux-parisc@vger.kernel.org, linux-kernel@vger.kernel.org, Richard Kuo , Paul Burton , linux-alpha@vger.kernel.org, Ley Foon Tan , Andrew Morton , linuxppc-dev@lists.ozlabs.org List-ID: On Sat, May 04, 2019 at 12:03:48AM +0800, Guo Ren wrote: > Hi Mike, > > Acked-by: Guo Ren > > On Thu, May 02, 2019 at 06:28:32PM +0300, Mike Rapoport wrote: > > The csky implementation pte_alloc_one(), pte_free_kernel() and pte_free() > > is identical to the generic except of lack of __GFP_ACCOUNT for the user > > PTEs allocation. > > > > Switch csky to use generic version of these functions. > Ok. > > > > > The csky implementation of pte_alloc_one_kernel() is not replaced because > > it does not clear the allocated page but rather sets each PTE in it to a > > non-zero value. > Yes, we must set each PTE to _PAGE_GLOBAL because hardware refill the > MMU TLB entry with two PTEs and it use the result of pte0.global | pte1.global. ^^^^^^^^^^^^^^^^^^^^^^^^^ correct: pte0.global & pte1.global > If pte0 is valid and pte1 is invalid, we must set _PAGE_GLOBAL in > invalid pte entry. Fortunately, there is no performance issue. > > > > > The pte_free_kernel() and pte_free() versions on csky are identical to the > > generic ones and can be simply dropped. > Ok. > > Best Regards > Guo Ren > > > > > Signed-off-by: Mike Rapoport > > --- > > arch/csky/include/asm/pgalloc.h | 30 +++--------------------------- > > 1 file changed, 3 insertions(+), 27 deletions(-) > > > > diff --git a/arch/csky/include/asm/pgalloc.h b/arch/csky/include/asm/pgalloc.h > > index d213bb4..98c571670 100644 > > --- a/arch/csky/include/asm/pgalloc.h > > +++ b/arch/csky/include/asm/pgalloc.h > > @@ -8,6 +8,9 @@ > > #include > > #include > > > > +#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL > > +#include /* for pte_{alloc,free}_one */ > > + > > static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, > > pte_t *pte) > > { > > @@ -39,33 +42,6 @@ static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm) > > return pte; > > } > > > > -static inline struct page *pte_alloc_one(struct mm_struct *mm) > > -{ > > - struct page *pte; > > - > > - pte = alloc_pages(GFP_KERNEL | __GFP_ZERO, 0); > > - if (!pte) > > - return NULL; > > - > > - if (!pgtable_page_ctor(pte)) { > > - __free_page(pte); > > - return NULL; > > - } > > - > > - return pte; > > -} > > - > > -static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) > > -{ > > - free_pages((unsigned long)pte, PTE_ORDER); > > -} > > - > > -static inline void pte_free(struct mm_struct *mm, pgtable_t pte) > > -{ > > - pgtable_page_dtor(pte); > > - __free_pages(pte, PTE_ORDER); > > -} > > - > > static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) > > { > > free_pages((unsigned long)pgd, PGD_ORDER); > > -- > > 2.7.4 > > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv