Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757437AbaJIP2w (ORCPT ); Thu, 9 Oct 2014 11:28:52 -0400 Received: from e23smtp04.au.ibm.com ([202.81.31.146]:38277 "EHLO e23smtp04.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757085AbaJIP2n (ORCPT ); Thu, 9 Oct 2014 11:28:43 -0400 From: "Aneesh Kumar K.V" To: Michael Neuling , greg@kroah.com, arnd@arndb.de, mpe@ellerman.id.au, benh@kernel.crashing.org Cc: mikey@neuling.org, anton@samba.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, jk@ozlabs.org, imunsie@au1.ibm.com, cbe-oss-dev@lists.ozlabs.org Subject: Re: [PATCH v4 09/16] powerpc/mm: Add new hash_page_mm() In-Reply-To: <1412758505-23495-10-git-send-email-mikey@neuling.org> References: <1412758505-23495-1-git-send-email-mikey@neuling.org> <1412758505-23495-10-git-send-email-mikey@neuling.org> User-Agent: Notmuch/0.18.1 (http://notmuchmail.org) Emacs/24.3.91.1 (x86_64-unknown-linux-gnu) Date: Thu, 09 Oct 2014 20:58:32 +0530 Message-ID: <87tx3d1cv3.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14100915-0013-0000-0000-000000545E25 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Michael Neuling writes: > From: Ian Munsie > > This adds a new function hash_page_mm() based on the existing hash_page(). > This version allows any struct mm to be passed in, rather than assuming > current. This is useful for servicing co-processor faults which are not in the > context of the current running process. > > We need to be careful here as the current hash_page() assumes current in a few > places. if you move cxl_slbia patch before this, then we could add additonal information here. 1) We use this to insert hpte entries on-behalf of co-processor. 2) we don't need to flush cpu slb entries when adding new hpte entries 3) We do flush the co-processor slb cache, if adding hpte entry result in a segement demotion or have mmu_ci_restrictions enabled. 4) We do update the slice array to indicate the new base page size 5) w.r.t co-processor on segment miss we look at slice array and add new slb entry using newly added copro_calculate_slb "powerpc/cell: Move data segment faulting code out of cell platform" > > Signed-off-by: Ian Munsie > Signed-off-by: Michael Neuling > --- > arch/powerpc/include/asm/mmu-hash64.h | 1 + > arch/powerpc/mm/hash_utils_64.c | 24 +++++++++++++++++------- > 2 files changed, 18 insertions(+), 7 deletions(-) > > diff --git a/arch/powerpc/include/asm/mmu-hash64.h b/arch/powerpc/include/asm/mmu-hash64.h > index aeabd02..764e141 100644 > --- a/arch/powerpc/include/asm/mmu-hash64.h > +++ b/arch/powerpc/include/asm/mmu-hash64.h > @@ -324,6 +324,7 @@ extern int __hash_page_64K(unsigned long ea, unsigned long access, > unsigned int local, int ssize); > struct mm_struct; > unsigned int hash_page_do_lazy_icache(unsigned int pp, pte_t pte, int trap); > +extern int hash_page_mm(struct mm_struct *mm, unsigned long ea, unsigned long access, unsigned long trap); > extern int hash_page(unsigned long ea, unsigned long access, unsigned long trap); > int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid, > pte_t *ptep, unsigned long trap, int local, int ssize, > diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c > index bbdb054..698834d 100644 > --- a/arch/powerpc/mm/hash_utils_64.c > +++ b/arch/powerpc/mm/hash_utils_64.c > @@ -904,7 +904,7 @@ void demote_segment_4k(struct mm_struct *mm, unsigned long addr) > return; > slice_set_range_psize(mm, addr, 1, MMU_PAGE_4K); > copro_flush_all_slbs(mm); > - if (get_paca_psize(addr) != MMU_PAGE_4K) { > + if ((get_paca_psize(addr) != MMU_PAGE_4K) && (current->mm == mm)) { > get_paca()->context = mm->context; > slb_flush_and_rebolt(); > } > @@ -989,12 +989,11 @@ static void check_paca_psize(unsigned long ea, struct mm_struct *mm, > * -1 - critical hash insertion error > * -2 - access not permitted by subpage protection mechanism > */ > -int hash_page(unsigned long ea, unsigned long access, unsigned long trap) > +int hash_page_mm(struct mm_struct *mm, unsigned long ea, unsigned long access, unsigned long trap) > { > enum ctx_state prev_state = exception_enter(); > pgd_t *pgdir; > unsigned long vsid; > - struct mm_struct *mm; > pte_t *ptep; > unsigned hugeshift; > const struct cpumask *tmp; > @@ -1008,7 +1007,6 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) > switch (REGION_ID(ea)) { > case USER_REGION_ID: > user_region = 1; > - mm = current->mm; > if (! mm) { > DBG_LOW(" user region with no mm !\n"); > rc = 1; > @@ -1019,7 +1017,6 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) > vsid = get_vsid(mm->context.id, ea, ssize); > break; > case VMALLOC_REGION_ID: > - mm = &init_mm; > vsid = get_kernel_vsid(ea, mmu_kernel_ssize); > if (ea < VMALLOC_END) > psize = mmu_vmalloc_psize; > @@ -1104,7 +1101,8 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) > WARN_ON(1); > } > #endif > - check_paca_psize(ea, mm, psize, user_region); > + if (current->mm == mm) > + check_paca_psize(ea, mm, psize, user_region); > > goto bail; > } > @@ -1145,7 +1143,8 @@ int hash_page(unsigned long ea, unsigned long access, unsigned long trap) > } > } > > - check_paca_psize(ea, mm, psize, user_region); > + if (current->mm == mm) > + check_paca_psize(ea, mm, psize, user_region); > #endif /* CONFIG_PPC_64K_PAGES */ > > #ifdef CONFIG_PPC_HAS_HASH_64K > @@ -1180,6 +1179,17 @@ bail: > exception_exit(prev_state); > return rc; > } > +EXPORT_SYMBOL_GPL(hash_page_mm); > + > +int hash_page(unsigned long ea, unsigned long access, unsigned long trap) > +{ > + struct mm_struct *mm = current->mm; > + > + if (REGION_ID(ea) == VMALLOC_REGION_ID) > + mm = &init_mm; > + > + return hash_page_mm(mm, ea, access, trap); > +} > EXPORT_SYMBOL_GPL(hash_page); > > void hash_preload(struct mm_struct *mm, unsigned long ea, > -- > 1.9.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/