From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 713FC2A8DA for ; Mon, 8 Apr 2024 08:43:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712565831; cv=none; b=rAtHDSwXMOQmQvQhfbpj7VihJvKWhZCBTqnTNGOC9YmZgamHGzJPXpzC1g+euPD4XkcVKLNjnxdzwo+a4MZ8wrui2Q0vcdvjtAYGuWyJbprBwVdzpPebZXLQWm0J0aQZgclUD6B7d7i3KYnAhvKntwG01PlNwCae89KVNtlJ9UM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712565831; c=relaxed/simple; bh=wjYKK2DUgmUMmbVGl6Cqe3/H4LMiRRRoPqZUt+qbJ/A=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pc4ky4+e0kNps5XgT02STzwKYQcIQll7rsPYJoDtQnxB219/2lmgSlho9F5K43uR+m5ZxYX5P9sNVM5xX5NDUxjKagZhJhP9MX8u0597dnwPxEHvjeo1bvvD080SLBYMkXxXjRmGqFX7APKjf0HCFAbV25vtf11sY0eaDW9o3bg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 05A9C1007; Mon, 8 Apr 2024 01:44:19 -0700 (PDT) Received: from [10.57.73.169] (unknown [10.57.73.169]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6C0F03F766; Mon, 8 Apr 2024 01:43:46 -0700 (PDT) Message-ID: <27718d41-32cb-4976-b50e-e9237da7aedf@arm.com> Date: Mon, 8 Apr 2024 09:43:44 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 3/3] arm64: tlb: Allow range operation for MAX_TLBI_RANGE_PAGES Content-Language: en-GB To: Gavin Shan , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, maz@kernel.org, oliver.upton@linux.dev, apopple@nvidia.com, rananta@google.com, mark.rutland@arm.com, v-songbaohua@oppo.com, yangyicong@hisilicon.com, shahuang@redhat.com, yihyu@redhat.com, shan.gavin@gmail.com References: <20240405035852.1532010-1-gshan@redhat.com> <20240405035852.1532010-4-gshan@redhat.com> From: Ryan Roberts In-Reply-To: <20240405035852.1532010-4-gshan@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 05/04/2024 04:58, Gavin Shan wrote: > MAX_TLBI_RANGE_PAGES pages is covered by SCALE#3 and NUM#31 and it's > supported now. Allow TLBI RANGE operation when the number of pages is > equal to MAX_TLBI_RANGE_PAGES in __flush_tlb_range_nosync(). > > Suggested-by: Marc Zyngier > Signed-off-by: Gavin Shan Reviewed-by: Ryan Roberts > --- > arch/arm64/include/asm/tlbflush.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h > index 243d71f7bc1f..95fbc8c05607 100644 > --- a/arch/arm64/include/asm/tlbflush.h > +++ b/arch/arm64/include/asm/tlbflush.h > @@ -446,11 +446,11 @@ static inline void __flush_tlb_range_nosync(struct vm_area_struct *vma, > * When not uses TLB range ops, we can handle up to > * (MAX_DVM_OPS - 1) pages; > * When uses TLB range ops, we can handle up to > - * (MAX_TLBI_RANGE_PAGES - 1) pages. > + * MAX_TLBI_RANGE_PAGES pages. > */ > if ((!system_supports_tlb_range() && > (end - start) >= (MAX_DVM_OPS * stride)) || > - pages >= MAX_TLBI_RANGE_PAGES) { > + pages > MAX_TLBI_RANGE_PAGES) { As a further enhancement, I wonder if it might be better to test: pages * 4 / MAX_TLBI_RANGE_PAGES > MAX_DVM_OPS Then add an extra loop over __flush_tlb_range_op(), like KVM does. The math is trying to express that there are a maximum of 4 tlbi range instructions for MAX_TLBI_RANGE_PAGES pages (1 per scale) and we only need to fall back to flushing the whole mm if it could generate more than MAX_DVM_OPS ops. > flush_tlb_mm(vma->vm_mm); > return; > }