From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Hunter Subject: Re: [PATCH v2 2/2] arm64: tlb: Use the TLBI RANGE feature in arm64 Date: Mon, 13 Jul 2020 15:27:50 +0100 Message-ID: <4040f429-21c8-0825-2ad4-97786c3fe7c1@nvidia.com> References: <20200710094420.517-1-yezhenyu2@huawei.com> <20200710094420.517-3-yezhenyu2@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20200710094420.517-3-yezhenyu2-hv44wF8Li93QT0dZR+AlfA@public.gmane.org> Content-Language: en-US Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Zhenyu Ye , catalin.marinas-5wv7dgnIgG8@public.gmane.org, will-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, suzuki.poulose-5wv7dgnIgG8@public.gmane.org, maz-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, steven.price-5wv7dgnIgG8@public.gmane.org, guohanjun-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, arm-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, xiexiangyou-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, prime.zeng-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org, zhangshaokun-C8/M+/jPZTeaMJb+Lgu22Q@public.gmane.org, kuhn.chenqun-hv44wF8Li93QT0dZR+AlfA@public.gmane.org, linux-tegra List-Id: linux-arch.vger.kernel.org On 10/07/2020 10:44, Zhenyu Ye wrote: > Add __TLBI_VADDR_RANGE macro and rewrite __flush_tlb_range(). > > When cpu supports TLBI feature, the minimum range granularity is > decided by 'scale', so we can not flush all pages by one instruction > in some cases. > > For example, when the pages = 0xe81a, let's start 'scale' from > maximum, and find right 'num' for each 'scale': > > 1. scale = 3, we can flush no pages because the minimum range is > 2^(5*3 + 1) = 0x10000. > 2. scale = 2, the minimum range is 2^(5*2 + 1) = 0x800, we can > flush 0xe800 pages this time, the num = 0xe800/0x800 - 1 = 0x1c. > Remaining pages is 0x1a; > 3. scale = 1, the minimum range is 2^(5*1 + 1) = 0x40, no page > can be flushed. > 4. scale = 0, we flush the remaining 0x1a pages, the num = > 0x1a/0x2 - 1 = 0xd. > > However, in most scenarios, the pages = 1 when flush_tlb_range() is > called. Start from scale = 3 or other proper value (such as scale = > ilog2(pages)), will incur extra overhead. > So increase 'scale' from 0 to maximum, the flush order is exactly > opposite to the example. > > Signed-off-by: Zhenyu Ye After this change I am seeing the following build errors ... /tmp/cckzq3FT.s: Assembler messages: /tmp/cckzq3FT.s:854: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:870: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:1095: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:1111: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:1964: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:1980: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:2286: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:2302: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:4833: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6' /tmp/cckzq3FT.s:4849: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6' /tmp/cckzq3FT.s:5090: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6' /tmp/cckzq3FT.s:5106: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6' /tmp/cckzq3FT.s:874: Error: attempt to move .org backwards /tmp/cckzq3FT.s:1115: Error: attempt to move .org backwards /tmp/cckzq3FT.s:1984: Error: attempt to move .org backwards /tmp/cckzq3FT.s:2306: Error: attempt to move .org backwards /tmp/cckzq3FT.s:4853: Error: attempt to move .org backwards /tmp/cckzq3FT.s:5110: Error: attempt to move .org backwards scripts/Makefile.build:280: recipe for target 'arch/arm64/mm/hugetlbpage.o' failed make[3]: *** [arch/arm64/mm/hugetlbpage.o] Error 1 scripts/Makefile.build:497: recipe for target 'arch/arm64/mm' failed make[2]: *** [arch/arm64/mm] Error 2 Cheers Jon -- nvpublic From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Subject: Re: [PATCH v2 2/2] arm64: tlb: Use the TLBI RANGE feature in arm64 References: <20200710094420.517-1-yezhenyu2@huawei.com> <20200710094420.517-3-yezhenyu2@huawei.com> From: Jon Hunter Message-ID: <4040f429-21c8-0825-2ad4-97786c3fe7c1@nvidia.com> Date: Mon, 13 Jul 2020 15:27:50 +0100 MIME-Version: 1.0 In-Reply-To: <20200710094420.517-3-yezhenyu2@huawei.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Zhenyu Ye , catalin.marinas@arm.com, will@kernel.org, suzuki.poulose@arm.com, maz@kernel.org, steven.price@arm.com, guohanjun@huawei.com, olof@lixom.net Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, arm@kernel.org, xiexiangyou@huawei.com, prime.zeng@hisilicon.com, zhangshaokun@hisilicon.com, kuhn.chenqun@huawei.com, linux-tegra List-ID: Message-ID: <20200713142750.S4nzLV-l1p-_PhwxtSwbrMHPZ7GRQzt0vgCo928WNoA@z> On 10/07/2020 10:44, Zhenyu Ye wrote: > Add __TLBI_VADDR_RANGE macro and rewrite __flush_tlb_range(). > > When cpu supports TLBI feature, the minimum range granularity is > decided by 'scale', so we can not flush all pages by one instruction > in some cases. > > For example, when the pages = 0xe81a, let's start 'scale' from > maximum, and find right 'num' for each 'scale': > > 1. scale = 3, we can flush no pages because the minimum range is > 2^(5*3 + 1) = 0x10000. > 2. scale = 2, the minimum range is 2^(5*2 + 1) = 0x800, we can > flush 0xe800 pages this time, the num = 0xe800/0x800 - 1 = 0x1c. > Remaining pages is 0x1a; > 3. scale = 1, the minimum range is 2^(5*1 + 1) = 0x40, no page > can be flushed. > 4. scale = 0, we flush the remaining 0x1a pages, the num = > 0x1a/0x2 - 1 = 0xd. > > However, in most scenarios, the pages = 1 when flush_tlb_range() is > called. Start from scale = 3 or other proper value (such as scale = > ilog2(pages)), will incur extra overhead. > So increase 'scale' from 0 to maximum, the flush order is exactly > opposite to the example. > > Signed-off-by: Zhenyu Ye After this change I am seeing the following build errors ... /tmp/cckzq3FT.s: Assembler messages: /tmp/cckzq3FT.s:854: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:870: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:1095: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:1111: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:1964: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:1980: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:2286: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:2302: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x7' /tmp/cckzq3FT.s:4833: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6' /tmp/cckzq3FT.s:4849: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6' /tmp/cckzq3FT.s:5090: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6' /tmp/cckzq3FT.s:5106: Error: unknown or missing operation name at operand 1 -- `tlbi rvae1is,x6' /tmp/cckzq3FT.s:874: Error: attempt to move .org backwards /tmp/cckzq3FT.s:1115: Error: attempt to move .org backwards /tmp/cckzq3FT.s:1984: Error: attempt to move .org backwards /tmp/cckzq3FT.s:2306: Error: attempt to move .org backwards /tmp/cckzq3FT.s:4853: Error: attempt to move .org backwards /tmp/cckzq3FT.s:5110: Error: attempt to move .org backwards scripts/Makefile.build:280: recipe for target 'arch/arm64/mm/hugetlbpage.o' failed make[3]: *** [arch/arm64/mm/hugetlbpage.o] Error 1 scripts/Makefile.build:497: recipe for target 'arch/arm64/mm' failed make[2]: *** [arch/arm64/mm] Error 2 Cheers Jon -- nvpublic