From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3032DD2F00D for ; Tue, 27 Jan 2026 12:46:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Subject:CC:To: From:Date:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=OLEIphBuwiCI4Q+wjDY7yvdGl/mzbImG+fV1xIKwe+8=; b=zqb0jmzyKCGH5qz6kJPSYWCddh f7YkqwMswYNiY8ax/pBVstdi99yfDF3DWKK3OSLjLNQbPT6pzkX0I9eTX6+XKXqnVnS05wgQoZmZV vKqvkrUO3FsggRjPR2XIGJrU9e3paanQi+D79tqv/Q9UI44+vPuO0GEPEO/PZX14Blfb1F0dPXTX+ aGSPe606Yq/4hfMR7x/qbNm3D7e4HkEqYyl2TThErdcVBQ8x9YHfdpFjN45MaZcxGaTjMGJNnFHrY mp6QsAtx/ba3lORn8oFtl2IsQvLyAd+80c0FUH38NnRIKzP3BvwUNosgNrMdSJ1KimXg3OQZw5eDc IfsdgX1w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vkiSB-0000000EGRK-29Z6; Tue, 27 Jan 2026 12:46:00 +0000 Received: from sinmsgout03.his.huawei.com ([119.8.177.38]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vkiS2-0000000EGQH-2xla for linux-arm-kernel@lists.infradead.org; Tue, 27 Jan 2026 12:45:54 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=OLEIphBuwiCI4Q+wjDY7yvdGl/mzbImG+fV1xIKwe+8=; b=DxoSt981sOYiN/cO+3wq3Y95MlPoUZ/uqoMb1Nbi4J9dCwXVN11GGacRSprEiGuT2clOkTA6+ vftw0YA/dUsK+oqqKADw4Zl1aK9yXQoqnykRTpKW6IP5g9za0FYo6zrdrCYpJFnVqwevs1ztQj+ 7cZgNrQ2hzddnTwgerbiHEk= Received: from frasgout.his.huawei.com (unknown [172.18.146.33]) by sinmsgout03.his.huawei.com (SkyGuard) with ESMTPS id 4f0lS920smzN0dD; Tue, 27 Jan 2026 20:43:05 +0800 (CST) Received: from mail.maildlp.com (unknown [172.18.224.83]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4f0lVM4VtvzJ46bP; Tue, 27 Jan 2026 20:44:59 +0800 (CST) Received: from dubpeml500005.china.huawei.com (unknown [7.214.145.207]) by mail.maildlp.com (Postfix) with ESMTPS id 87BCE40569; Tue, 27 Jan 2026 20:45:35 +0800 (CST) Received: from localhost (10.203.177.15) by dubpeml500005.china.huawei.com (7.214.145.207) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 27 Jan 2026 12:45:34 +0000 Date: Tue, 27 Jan 2026 12:45:33 +0000 From: Jonathan Cameron To: Ryan Roberts CC: Will Deacon , Ard Biesheuvel , Catalin Marinas , Mark Rutland , Linus Torvalds , Oliver Upton , Marc Zyngier , "Dev Jain" , Linu Cherian , , Subject: Re: [PATCH v2 11/13] arm64: mm: More flags for __flush_tlb_range() Message-ID: <20260127124533.0000302e@huawei.com> In-Reply-To: <20260119172202.1681510-12-ryan.roberts@arm.com> References: <20260119172202.1681510-1-ryan.roberts@arm.com> <20260119172202.1681510-12-ryan.roberts@arm.com> X-Mailer: Claws Mail 4.3.0 (GTK 3.24.42; x86_64-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.203.177.15] X-ClientProxiedBy: lhrpeml100012.china.huawei.com (7.191.174.184) To dubpeml500005.china.huawei.com (7.214.145.207) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260127_044552_730515_88106E3A X-CRM114-Status: GOOD ( 34.16 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, 19 Jan 2026 17:21:58 +0000 Ryan Roberts wrote: > Refactor function variants with "_nosync", "_local" and "_nonotify" into > a single __always_inline implementation that takes flags and rely on > constant folding to select the parts that are actually needed at any > given callsite, based on the provided flags. > > Flags all live in the tlbf_t (TLB flags) type; TLBF_NONE (0) continues > to provide the strongest semantics (i.e. evict from walk cache, > broadcast, synchronise and notify). Each flag reduces the strength in > some way; TLBF_NONOTIFY, TLBF_NOSYNC and TLBF_NOBROADCAST are added to > complement the existing TLBF_NOWALKCACHE. Unless I'm missing something the case of TLBF_NOBROADCAST but not TLBF_NOWALKCACHE isn't currently used. I wonder if bringing that in with a user will make it easier to see what is going on. Otherwise, 3 vs 2 underscores? Can we come up with something easier to read than that? > > The result is a clearer, simpler, more powerful API. > > Signed-off-by: Ryan Roberts > --- > arch/arm64/include/asm/tlbflush.h | 107 +++++++++++++++++++----------- > arch/arm64/mm/contpte.c | 9 ++- > 2 files changed, 74 insertions(+), 42 deletions(-) > > diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h > index 1ad1c864e1f8..f03831cd8719 100644 > --- a/arch/arm64/include/asm/tlbflush.h > +++ b/arch/arm64/include/asm/tlbflush.h > @@ -107,6 +107,12 @@ static inline unsigned long get_trans_granule(void) > > typedef void (*tlbi_op)(u64 arg); > > +static __always_inline void vae1(u64 arg) > +{ > + __tlbi(vae1, arg); > + __tlbi_user(vae1, arg); > +} > + > static __always_inline void vae1is(u64 arg) > { > __tlbi(vae1is, arg); > @@ -275,7 +281,10 @@ static inline void __tlbi_level(tlbi_op op, u64 addr, u32 level) > * no invalidation may take place. In the case where the level > * cannot be easily determined, the value TLBI_TTL_UNKNOWN will > * perform a non-hinted invalidation. flags may be TLBF_NONE (0) or > - * TLBF_NOWALKCACHE (elide eviction of walk cache entries). > + * any combination of TLBF_NOWALKCACHE (elide eviction of walk > + * cache entries), TLBF_NONOTIFY (don't call mmu notifiers), > + * TLBF_NOSYNC (don't issue trailing dsb) and TLBF_NOBROADCAST > + * (only perform the invalidation for the local cpu). > * > * local_flush_tlb_page(vma, addr) > * Local variant of flush_tlb_page(). Stale TLB entries may > @@ -285,12 +294,6 @@ static inline void __tlbi_level(tlbi_op op, u64 addr, u32 level) > * Same as local_flush_tlb_page() except MMU notifier will not be > * called. > * > - * local_flush_tlb_contpte(vma, addr) > - * Invalidate the virtual-address range > - * '[addr, addr+CONT_PTE_SIZE)' mapped with contpte on local CPU > - * for the user address space corresponding to 'vma->mm'. Stale > - * TLB entries may remain in remote CPUs. > - * > * Finally, take a look at asm/tlb.h to see how tlb_flush() is implemented > * on top of these routines, since that is our interface to the mmu_gather > * API as used by munmap() and friends. > @@ -435,6 +438,12 @@ static inline void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch) > * operations can only span an even number of pages. We save this for last to > * ensure 64KB start alignment is maintained for the LPA2 case. > */ > +static __always_inline void rvae1(u64 arg) > +{ > + __tlbi(rvae1, arg); > + __tlbi_user(rvae1, arg); > +} > + > static __always_inline void rvae1is(u64 arg) > { > __tlbi(rvae1is, arg); > @@ -541,15 +550,23 @@ typedef unsigned __bitwise tlbf_t; > /* Invalidate tlb entries only, leaving the page table walk cache intact. */ > #define TLBF_NOWALKCACHE ((__force tlbf_t)BIT(0)) > > -static inline void __flush_tlb_range_nosync(struct mm_struct *mm, > - unsigned long start, unsigned long end, > - unsigned long stride, int tlb_level, > - tlbf_t flags) > +/* Skip the trailing dsb after issuing tlbi. */ > +#define TLBF_NOSYNC ((__force tlbf_t)BIT(1)) > + > +/* Suppress tlb notifier callbacks for this flush operation. */ > +#define TLBF_NONOTIFY ((__force tlbf_t)BIT(2)) > + > +/* Perform the tlbi locally without broadcasting to other CPUs. */ > +#define TLBF_NOBROADCAST ((__force tlbf_t)BIT(3)) > + > +static __always_inline void ___flush_tlb_range(struct vm_area_struct *vma, Can we come up with anything better for naming than more underscores? My eyes skipped over there being 3 here rather than 2 and I got rather confused as a result. Maybe at least make it excessive and go from 2 to 4+? > + unsigned long start, unsigned long end, > + unsigned long stride, int tlb_level, > + tlbf_t flags) > { > + struct mm_struct *mm = vma->vm_mm; > unsigned long asid, pages; > > - start = round_down(start, stride); > - end = round_up(end, stride); > pages = (end - start) >> PAGE_SHIFT; > > if (__flush_tlb_range_limit_excess(pages, stride)) { > @@ -557,17 +574,41 @@ static inline void __flush_tlb_range_nosync(struct mm_struct *mm, > return; > } > > - dsb(ishst); > + if (!(flags & TLBF_NOBROADCAST)) > + dsb(ishst); > + else > + dsb(nshst); > + > asid = ASID(mm); > > - if (flags & TLBF_NOWALKCACHE) > - __flush_s1_tlb_range_op(vale1is, start, pages, stride, > - asid, tlb_level); > - else > + switch (flags & (TLBF_NOWALKCACHE | TLBF_NOBROADCAST)) { > + case TLBF_NONE: > __flush_s1_tlb_range_op(vae1is, start, pages, stride, > - asid, tlb_level); > + asid, tlb_level); > + break; > + case TLBF_NOWALKCACHE: > + __flush_s1_tlb_range_op(vale1is, start, pages, stride, > + asid, tlb_level); > + break; > + case TLBF_NOBROADCAST: > + __flush_s1_tlb_range_op(vae1, start, pages, stride, > + asid, tlb_level); > + break; > + case TLBF_NOWALKCACHE | TLBF_NOBROADCAST: > + __flush_s1_tlb_range_op(vale1, start, pages, stride, > + asid, tlb_level); > + break; > + } > + > + if (!(flags & TLBF_NONOTIFY)) > + mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end); > > - mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end); > + if (!(flags & TLBF_NOSYNC)) { > + if (!(flags & TLBF_NOBROADCAST)) > + dsb(ish); > + else > + dsb(nsh); > + } > } > > static inline void __flush_tlb_range(struct vm_area_struct *vma, > @@ -575,24 +616,9 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma, > unsigned long stride, int tlb_level, > tlbf_t flags) > { > - __flush_tlb_range_nosync(vma->vm_mm, start, end, stride, > - tlb_level, flags); > - dsb(ish); > -} > - > -static inline void local_flush_tlb_contpte(struct vm_area_struct *vma, > - unsigned long addr) > -{ > - unsigned long asid; > - > - addr = round_down(addr, CONT_PTE_SIZE); > - > - dsb(nshst); > - asid = ASID(vma->vm_mm); > - __flush_s1_tlb_range_op(vale1, addr, CONT_PTES, PAGE_SIZE, asid, 3); > - mmu_notifier_arch_invalidate_secondary_tlbs(vma->vm_mm, addr, > - addr + CONT_PTE_SIZE); > - dsb(nsh); > + start = round_down(start, stride); > + end = round_up(end, stride); > + ___flush_tlb_range(vma, start, end, stride, tlb_level, flags); > } > > static inline void flush_tlb_range(struct vm_area_struct *vma, > @@ -645,7 +671,10 @@ static inline void __flush_tlb_kernel_pgtable(unsigned long kaddr) > static inline void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch, > struct mm_struct *mm, unsigned long start, unsigned long end) > { > - __flush_tlb_range_nosync(mm, start, end, PAGE_SIZE, 3, TLBF_NOWALKCACHE); > + struct vm_area_struct vma = { .vm_mm = mm, .vm_flags = 0 }; > + > + __flush_tlb_range(&vma, start, end, PAGE_SIZE, 3, > + TLBF_NOWALKCACHE | TLBF_NOSYNC); > } > > static inline bool __pte_flags_need_flush(ptdesc_t oldval, ptdesc_t newval) > diff --git a/arch/arm64/mm/contpte.c b/arch/arm64/mm/contpte.c > index 1a12bb728ee1..ec17a0e70415 100644 > --- a/arch/arm64/mm/contpte.c > +++ b/arch/arm64/mm/contpte.c > @@ -527,8 +527,8 @@ int contpte_ptep_clear_flush_young(struct vm_area_struct *vma, > * eliding the trailing DSB applies here. > */ > addr = ALIGN_DOWN(addr, CONT_PTE_SIZE); > - __flush_tlb_range_nosync(vma->vm_mm, addr, addr + CONT_PTE_SIZE, > - PAGE_SIZE, 3, TLBF_NOWALKCACHE); > + __flush_tlb_range(vma, addr, addr + CONT_PTE_SIZE, > + PAGE_SIZE, 3, TLBF_NOWALKCACHE | TLBF_NOSYNC); > } > > return young; > @@ -623,7 +623,10 @@ int contpte_ptep_set_access_flags(struct vm_area_struct *vma, > __ptep_set_access_flags(vma, addr, ptep, entry, 0); > > if (dirty) > - local_flush_tlb_contpte(vma, start_addr); > + __flush_tlb_range(vma, start_addr, > + start_addr + CONT_PTE_SIZE, > + PAGE_SIZE, 3, > + TLBF_NOWALKCACHE | TLBF_NOBROADCAST); > } else { > __contpte_try_unfold(vma->vm_mm, addr, ptep, orig_pte); > __ptep_set_access_flags(vma, addr, ptep, entry, dirty);