From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guo Ren Subject: Re: [PATCH 05/15] csky: switch to generic version of pte allocation Date: Sat, 4 May 2019 00:03:48 +0800 Message-ID: <20190503160348.GA9526@guoren-Inspiron-7460> References: <1556810922-20248-1-git-send-email-rppt@linux.ibm.com> <1556810922-20248-6-git-send-email-rppt@linux.ibm.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556899448; bh=9K26hWqGMesApQFdaAhFuNyta2kJgrhs2hDdmQ00qcY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HpZWwg5gL0lVYH9xXr2lFjIs4Hr4EFxgLMU0fvIEmuLFdJqilQ6jQYN4Ocb6SStWw iJWfiG66zAQYSvJeB8l3sHAhW93+kPdDD0sZUeypbCGK/KXfyMm98BkvfNuimDaaPM OT2y75fIlpEILXIObpyUg29WsNXovSO+5g+0/f6w= Content-Disposition: inline In-Reply-To: <1556810922-20248-6-git-send-email-rppt@linux.ibm.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane.org@lists.ozlabs.org Sender: "Linuxppc-dev" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Mike Rapoport Cc: Michal Hocko , Catalin Marinas , Palmer Dabbelt , linux-mips@vger.kernel.org, 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 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. 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 >