From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x241.google.com (mail-pf0-x241.google.com [IPv6:2607:f8b0:400e:c00::241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3ryWRd2b5QzDqdw for ; Mon, 25 Jul 2016 16:23:57 +1000 (AEST) Received: by mail-pf0-x241.google.com with SMTP id h186so11314361pfg.2 for ; Sun, 24 Jul 2016 23:23:57 -0700 (PDT) Date: Mon, 25 Jul 2016 16:23:49 +1000 From: Nicholas Piggin To: "Aneesh Kumar K.V" Cc: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, linuxppc-dev@lists.ozlabs.org Subject: Re: [PATCH for-4.8 V2 03/10] powerpc/mm/radix: Add radix_set_pte to use in early init Message-ID: <20160725162349.1bc9a9fe@roar.ozlabs.ibm.com> In-Reply-To: <1469265163-1491-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com> References: <1469265163-1491-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <1469265163-1491-4-git-send-email-aneesh.kumar@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Sat, 23 Jul 2016 14:42:36 +0530 "Aneesh Kumar K.V" wrote: > We want to use the static key based feature check in set_pte_at. Since > we call radix__map_kernel_page early in boot before jump label is > initialized we can't call set_pte_at there. Add radix__set_pte for the > same. > > Signed-off-by: Aneesh Kumar K.V > --- > arch/powerpc/mm/pgtable-radix.c | 23 ++++++++++++++++++++++- > 1 file changed, 22 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/mm/pgtable-radix.c > b/arch/powerpc/mm/pgtable-radix.c index 003ff48a11b6..6d2eb76b508e > 100644 --- a/arch/powerpc/mm/pgtable-radix.c > +++ b/arch/powerpc/mm/pgtable-radix.c > @@ -39,6 +39,27 @@ static __ref void *early_alloc_pgtable(unsigned > long size) > return pt; > } > +/* > + * set_pte stores a linux PTE into the linux page table. > + */ > +static void radix__set_pte(struct mm_struct *mm, unsigned long addr, > pte_t *ptep, > + pte_t pte) > +{ > + /* > + * When handling numa faults, we already have the pte marked > + * _PAGE_PRESENT, but we can be sure that it is not in hpte. > + * Hence we can use set_pte_at for them. > + */ > + VM_WARN_ON(pte_present(*ptep) && !pte_protnone(*ptep)); > + > + /* > + * Add the pte bit when tryint set a pte > + */ > + pte = __pte(pte_val(pte) | _PAGE_PTE); > + > + /* Perform the setting of the PTE */ > + radix__set_pte_at(mm, addr, ptep, pte, 0); > +} > > int radix__map_kernel_page(unsigned long ea, unsigned long pa, > pgprot_t flags, > @@ -102,7 +123,7 @@ int radix__map_kernel_page(unsigned long ea, > unsigned long pa, } > > set_the_pte: > - set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, > flags)); > + radix__set_pte(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, > flags)); smp_wmb(); What we have in existing code is set_pte_at() function that adds the _PAGE_PTE bit, then calls __set_pte_at(), which calls radix or hash version of __set_pte_at(). Now we also have radix__set_pte(), which has the function of the set_pte_at(), which is starting to confuse the naming convention. The new function is a radix-only set_pte_at(), rather than the radix implementation that gets called via set_pte(). set_pte_at_radix()? That kind of sucks too, though. It might be better if the radix/hash variants were called __radix__set_pte_at(), and this new function was called radix__set_pte_at(). Thanks, Nick