From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1516789737; cv=none; d=google.com; s=arc-20160816; b=P97KouncwmICUo0Bzsqo0ywkm9KiLtcU/H3t4FQxcs/XZ3VIuBXNVbXZS3/fv7OR6w 8XSs76l1Oxd7RBieUYYimXrz7v1sB580FD0SU7HcARQIqPed5fvNSA2/X9PxPnYlAMIB M7esXrWWGTpKHdHxQAkcIH3fdObJBQsZ8QZSH+6AaYa1Ku2XTIv6+yQ0Vg1KkSD6VVhs WhmLqW5Ta2WuV4iD2Pwc1OKv3VkFghHCmMJ+C1x21cu5gkSX6Tl79YJxy2pt7hWzuZZW QL86PCYbbt8q1/3R7QnmAXsC6acAgev2oFPLOSy/PtW0jgMHV71fl7VPgmsE4pPIbxZF oRTA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=cc:to:subject:message-id:date:from:references:in-reply-to:sender :mime-version:dkim-signature:arc-authentication-results; bh=/RlZjECWKaDGOjYJRIPUXltWAkXVJNwPWTZiIoPLSLE=; b=HJP5Xa1fnyY9nWQMsXNMfNiuAZUCy+kALmxMpziJkEmALpR/fDO+Ym/yNwBXI4uicL 93UAHSFMjCEjTS3TD+V2lHFE94dyPmqo23SDQSEvQOc6hIAcXIIlBZAPcQ5S5EZTsHc/ tAmtKu4hm2fByC+LNoNCZe48XCTHp+CMeciF9YK9J3rCQXGjL1QQo19QKKyXQRbr5gCe ZrNTFGDevN4iprFJ38BJqnbgmlM6ZlYLn4il0trCHihEXjD792TTgYwxyWY05Day6eY9 2S/9i2Lha7vrY37ltdclJbdTaMmxRpQJ9MPGYiVUH9J9vclitDi7xJXKovp8SNzupqz9 uOEg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=WE8a3xA4; spf=pass (google.com: domain of arndbergmann@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=arndbergmann@gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=WE8a3xA4; spf=pass (google.com: domain of arndbergmann@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=arndbergmann@gmail.com X-Google-Smtp-Source: AH8x22484n1eNRZXyNazM8Uy06sZ69e/PXey7lv1JL7nqo/dLoFZlXf1ov/Jdyd4lWwqQVg9OA97TytkfcQU12V2VX0= MIME-Version: 1.0 Sender: arndbergmann@gmail.com In-Reply-To: <20180124090519.6680-1-ynorov@caviumnetworks.com> References: <20180124090519.6680-1-ynorov@caviumnetworks.com> From: Arnd Bergmann Date: Wed, 24 Jan 2018 11:28:55 +0100 X-Google-Sender-Auth: ZwKSIjt_KbdPbPeAamALAiswap8 Message-ID: Subject: Re: [PATCH RFC 0/3] API for 128-bit IO access To: Yury Norov Cc: Linux ARM , linux-arch , Linux Kernel Mailing List , "open list:HARDWARE RANDOM NUMBER GENERATOR CORE" , Al Viro , Andrew Morton , Andrew Pinski , Catalin Marinas , "David S . Miller" , Geethasowjanya Akula , Greg Kroah-Hartman , Ingo Molnar , Kees Cook , Laura Abbott , Nicholas Piggin , Sunil Goutham , Will Deacon Content-Type: text/plain; charset="UTF-8" X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1590464072821012974?= X-GMAIL-MSGID: =?utf-8?q?1590469315574470138?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed, Jan 24, 2018 at 10:05 AM, Yury Norov wrote: > This series adds API for 128-bit memory IO access and enables it for ARM64. > The original motivation for 128-bit API came from new Cavium network device > driver. The hardware requires 128-bit access to make things work. See > description in patch 3 for details. We might also want to do something similar to the include/linux/io-64-nonatomic-lo-hi.h and hi-lo.h files, to simulate 128-bit access using pairs of 64-bit access on other targets. It's apparently driver specific which half you need to do first to make it work, so we need both. > Also, starting from ARMv8.4, stp and ldp instructions become atomic, and > API for 128-bit access would be helpful in core arm64 code. > > This series is RFC. I'd like to collect opinions on idea and implementation > details. > * I didn't implement all 128-bit operations existing for 64-bit variables > and other types (__swab128p etc). Do we need them all right now, or we > can add them when actually needed? I think in this case it's better to do them all at once. > * u128 name is already used in crypto code. So here I use __uint128_t that > comes from GCC for 128-bit types. Should I rename existing type in crypto > and make core code for 128-bit variables consistent with u64, u32 etc? (I > think yes, but would like to ask crypto people for it.) Hmm, that file probably predates the __uint128_t support. My guess would be that the crypto code using it can actually benefit from the new types as well, so maybe move the existing file to include/linux/int128.h and add an #if/#else logic to it so we use 'typedef __uint128_t __u128' if that is available. > * Some compilers don't support __uint128_t, so I protected all generic code > with config option HAVE_128BIT_ACCESS. I think it's OK, but... That would be nicely solved by using the #if/#else definition above. > * For 128-bit read/write functions I take suffix 'o', which means read/write > the octet of bytes. Is this name OK? Can't think of anything better. It's not an octet though, but 16 bytes ('q' is for quadword, meaning four 16-bit words in Intel terminology). > * my mips-linux-gnu-gcc v6.3.0 doesn't support __uint128_t, and I > don't have other BE setup on hand, so BE case is formally not tested. > BE code for arm64 is looking well though. I've run it through my collection of compilers, it seems that most but not all 64-bit targets support it (exceptions appear to be older versions of gcc for s390x and parisc), and none of the 32-bit targets do: $ for i in /home/arnd/cross-gcc/bin/*gcc-[3-8]* ; do echo -n $i" " ; echo '__uint128_t v;' | $i -xc -S - -o /dev/null && echo ok ; done /home/arnd/cross-gcc/bin/aarch64-linux-gcc-4.8.5 ok /home/arnd/cross-gcc/bin/aarch64-linux-gcc-4.9.3 ok /home/arnd/cross-gcc/bin/aarch64-linux-gcc-4.9.4 ok /home/arnd/cross-gcc/bin/aarch64-linux-gcc-5.2.1 ok /home/arnd/cross-gcc/bin/aarch64-linux-gcc-5.4.1 ok /home/arnd/cross-gcc/bin/aarch64-linux-gcc-5.5.0 ok /home/arnd/cross-gcc/bin/aarch64-linux-gcc-6.3.1 ok /home/arnd/cross-gcc/bin/aarch64-linux-gcc-7.0.0 ok /home/arnd/cross-gcc/bin/aarch64-linux-gcc-7.0.1 ok /home/arnd/cross-gcc/bin/aarch64-linux-gcc-7.1.1 ok /home/arnd/cross-gcc/bin/aarch64-linux-gcc-7.2.1 ok /home/arnd/cross-gcc/bin/aarch64-linux-gcc-8.0.0 ok /home/arnd/cross-gcc/bin/alpha-linux-gcc-4.1.3 ok /home/arnd/cross-gcc/bin/alpha-linux-gcc-4.3.6 ok /home/arnd/cross-gcc/bin/alpha-linux-gcc-4.9.3 ok /home/arnd/cross-gcc/bin/alpha-linux-gcc-7.2.1 ok /home/arnd/cross-gcc/bin/am33_2.0-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/am33_2.0-linux-gcc-5.2.1 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/am33_2.0-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/arc-elf-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-3.4.6 ok /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-4.3.6 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-4.4.7 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-4.5.4 :1:13: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-4.6.4 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-4.7.4 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-4.8.5 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-4.9.0 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-4.9.1 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-4.9.2 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-4.9.4 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-5.0.0 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-5.1.1 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-5.2.1 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-5.3.1 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-5.4.1 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-5.5.0 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-6.0.0 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-6.1.1 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-6.3.1 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-7.0.0 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-7.0.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-7.1.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/arm-linux-gnueabi-gcc-8.0.0 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/bfin-uclinux-gcc-7.0.0 bfin-uclinux-gcc-7.0.0: error trying to exec 'cc1': execvp: No such file or directory /home/arnd/cross-gcc/bin/bfin-uclinux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/c6x-elf-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/cris-linux-gcc-4.1.3 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/cris-linux-gcc-4.3.6 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/cris-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/cris-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/frv-linux-gcc-4.1.3 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/frv-linux-gcc-4.3.6 :1: internal compiler error: in default_secondary_reload, at targhooks.c:618 Please submit a full bug report, with preprocessed source if appropriate. See for instructions. /home/arnd/cross-gcc/bin/frv-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/frv-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/h8300-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/hppa64-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/hppa64-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/hppa-linux-gcc-4.1.3 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/hppa-linux-gcc-4.3.6 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/hppa-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/hppa-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/i386-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/i386-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/ia64-linux-gcc-7.2.1 ok /home/arnd/cross-gcc/bin/m32r-linux-gcc-4.1.3 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/m32r-linux-gcc-4.3.6 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/m32r-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/m32r-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/m68k-linux-gcc-4.1.3 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/m68k-linux-gcc-4.3.6 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/m68k-linux-gcc-6.0.0 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/m68k-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/microblaze-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/microblaze-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/mips64-linux-gcc-4.9.3 ok /home/arnd/cross-gcc/bin/mips64-linux-gcc-7.2.1 ok /home/arnd/cross-gcc/bin/mips-linux-gcc-4.0.4 :1: error: syntax error before 'v' :1: warning: data definition has no type or storage class /home/arnd/cross-gcc/bin/mips-linux-gcc-4.1.3 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/mips-linux-gcc-4.3.6 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/mips-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/mips-linux-gcc-7.0.0 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/mips-linux-gcc-7.0.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/mips-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/nios2-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/parisc-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/powerpc64-linux-gcc-4.1.3 ok /home/arnd/cross-gcc/bin/powerpc64-linux-gcc-4.3.6 ok /home/arnd/cross-gcc/bin/powerpc64-linux-gcc-4.9.3 ok /home/arnd/cross-gcc/bin/powerpc64-linux-gcc-7.2.1 ok /home/arnd/cross-gcc/bin/powerpc-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/powerpc-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/riscv32-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/riscv64-linux-gcc-7.2.1 ok /home/arnd/cross-gcc/bin/s390-linux-gcc-4.1.3 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/s390-linux-gcc-4.3.6 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/s390-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/s390-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/sh2-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/sh3-linux-gcc-4.1.3 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/sh3-linux-gcc-4.3.6 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/sh3-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/sh4-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/sh-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/sparc64-linux-gcc-4.9.3 ok /home/arnd/cross-gcc/bin/sparc64-linux-gcc-7.2.1 ok /home/arnd/cross-gcc/bin/sparc-linux-gcc-4.1.3 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/sparc-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/sparc-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/tilegx-linux-gcc-7.2.1 ok /home/arnd/cross-gcc/bin/tilepro-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'? /home/arnd/cross-gcc/bin/x86_64-linux-gcc-3.4.6 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-4.0.4 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-4.1.3 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-4.2.5 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-4.3.6 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-4.4.7 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-4.5.4 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-4.6.4 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-4.7.4 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-4.8.5 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-4.9.3 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-4.9.4 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-5.4.1 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-5.5.0 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-6.1.1 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-6.3.1 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-7.0.0 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-7.0.1 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-7.1.1 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-7.2.1 ok /home/arnd/cross-gcc/bin/x86_64-linux-gcc-8.0.0 ok /home/arnd/cross-gcc/bin/xtensa-linux-gcc-4.1.3 :1: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'v' /home/arnd/cross-gcc/bin/xtensa-linux-gcc-4.9.3 :1:1: error: unknown type name '__uint128_t' /home/arnd/cross-gcc/bin/xtensa-linux-gcc-7.2.1 :1:1: error: unknown type name '__uint128_t'; did you mean '__int128'?