From nobody Sun Feb 8 20:52:27 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 926D6158219; Thu, 1 Aug 2024 07:17:03 +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=1722496625; cv=none; b=Ie2kaepS6Z0SQkmIsEsqf4U7b27o5qav93ugUW0/TDJ1nTIRhsUMDM4cWkpkzFAHm6GPEVbOHvIkfHUzw3K5QGIHuJexvgy/fFM74FDos8GBWs9+XP5FXiyL9Rc7OKru7RLYYCl2VX3laamhnpMdRfLW1v2FqlPwiaueQKfgsxQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722496625; c=relaxed/simple; bh=zKcECkm8nar+w75DnzuxDPf4ZLyYPifOgs5mMZbvdEQ=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=kI2t1VOh86l8DVv3a3jQQxjvxah+/tT+qLPF7ph13xeJBDkFQKbdIhE79Xcei6BnxSXYVb0Eihielim6uPuGucXPTllQAYkEkrMR/4iDiqjLzFFpGsrHjNSFmZGL6fpfi+VWE+hXlfOjFaJlgeHWv/xgsWRYg7jqP4YE0ETqJxk= 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 6FDC01063; Thu, 1 Aug 2024 00:17:28 -0700 (PDT) Received: from a077893.arm.com (unknown [10.163.56.112]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id B508C3F766; Thu, 1 Aug 2024 00:16:59 -0700 (PDT) From: Anshuman Khandual To: linux-kernel@vger.kernel.org Cc: anshuman.khandual@arm.com, ardb@kernel.org, Andrew Morton , Yury Norov , Rasmus Villemoes , Arnd Bergmann , linux-arch@vger.kernel.org Subject: [PATCH V3 1/2] uapi: Define GENMASK_U128 Date: Thu, 1 Aug 2024 12:46:45 +0530 Message-Id: <20240801071646.682731-2-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240801071646.682731-1-anshuman.khandual@arm.com> References: <20240801071646.682731-1-anshuman.khandual@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This adds GENMASK_U128() and __GENMASK_U128() macros using __BITS_PER_U128 and __int128 data types. These macros will be used in providing support for generating 128 bit masks. Cc: Yury Norov Cc: Rasmus Villemoes Cc: Arnd Bergmann > Cc: linux-kernel@vger.kernel.org Cc: linux-arch@vger.kernel.org Reviewed-by: Arnd Bergmann Signed-off-by: Anshuman Khandual Reviewed-by: Yury Norov --- include/linux/bits.h | 13 +++++++++++++ include/uapi/linux/bits.h | 3 +++ include/uapi/linux/const.h | 15 +++++++++++++++ 3 files changed, 31 insertions(+) diff --git a/include/linux/bits.h b/include/linux/bits.h index 0eb24d21aac2..bf99feb5570e 100644 --- a/include/linux/bits.h +++ b/include/linux/bits.h @@ -36,4 +36,17 @@ #define GENMASK_ULL(h, l) \ (GENMASK_INPUT_CHECK(h, l) + __GENMASK_ULL(h, l)) =20 +/* + * Missing asm support + * + * __GENMASK_U128() depends on _BIT128() which would not work + * in the asm code, as it shifts an 'unsigned __init128' data + * type instead of direct representation of 128 bit constants + * such as long and unsigned long. The fundamental problem is + * that a 128 bit constant will get silently truncated by the + * gcc compiler. + */ +#define GENMASK_U128(h, l) \ + (GENMASK_INPUT_CHECK(h, l) + __GENMASK_U128(h, l)) + #endif /* __LINUX_BITS_H */ diff --git a/include/uapi/linux/bits.h b/include/uapi/linux/bits.h index 3c2a101986a3..4d4b7b08003c 100644 --- a/include/uapi/linux/bits.h +++ b/include/uapi/linux/bits.h @@ -12,4 +12,7 @@ (((~_ULL(0)) - (_ULL(1) << (l)) + 1) & \ (~_ULL(0) >> (__BITS_PER_LONG_LONG - 1 - (h)))) =20 +#define __GENMASK_U128(h, l) \ + ((_BIT128((h) + 1)) - (_BIT128(l))) + #endif /* _UAPI_LINUX_BITS_H */ diff --git a/include/uapi/linux/const.h b/include/uapi/linux/const.h index a429381e7ca5..5be12e8f8f9c 100644 --- a/include/uapi/linux/const.h +++ b/include/uapi/linux/const.h @@ -28,6 +28,21 @@ #define _BITUL(x) (_UL(1) << (x)) #define _BITULL(x) (_ULL(1) << (x)) =20 +/* + * Missing asm support + * + * __BIT128() would not work in the asm code, as it shifts an + * 'unsigned __init128' data type as direct representation of + * 128 bit constants is not supported in the gcc compiler, as + * they get silently truncated. + * + * TODO: Please revisit this implementation when gcc compiler + * starts representing 128 bit constants directly like long + * and unsigned long etc. Subsequently drop the comment for + * GENMASK_U128() which would then start supporting asm code. + */ +#define _BIT128(x) ((unsigned __int128)(1) << (x)) + #define __ALIGN_KERNEL(x, a) __ALIGN_KERNEL_MASK(x, (__typeof__(x))(a) - = 1) #define __ALIGN_KERNEL_MASK(x, mask) (((x) + (mask)) & ~(mask)) =20 --=20 2.30.2 From nobody Sun Feb 8 20:52:27 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 6F3A6158219; Thu, 1 Aug 2024 07:17:07 +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=1722496629; cv=none; b=TOW4k96aPe04g9P6uJ7T1KUOo+gPS370HxxAxU5DUpzc3keNXZCUGi9SIdUj08NO0j1Um0K1x6XZiI3etsEq2H9NEBJeMl+G4wolae4WkdzoK4EodF2KRcY+28mReXDrJ6yIYQT+cPuq7Aw1szjcP72JeZUKQ+gpxfRyt5s8gwU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722496629; c=relaxed/simple; bh=qqjftvWxtSMvNLDG28PttSQy2YcANG4yqZsJe6TwPUc=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=IKpem1SN4D0J+P06mT1lFjRhK1chPhkP4k3TtpT3Fg/NYo9bX7nICcyE+nYqYwyqPl0yFSZ+M3Q2/D4vwppxeUwqBS2E3u1Ux8vjCvKI9cJYgyABFoTotaCpnitnNlZoNgRhlTDwxbwapKl0qajdrNCuEC4QC/3PNfTb/Azj3LE= 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 22D321007; Thu, 1 Aug 2024 00:17:32 -0700 (PDT) Received: from a077893.arm.com (unknown [10.163.56.112]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 5E8F23F766; Thu, 1 Aug 2024 00:17:03 -0700 (PDT) From: Anshuman Khandual To: linux-kernel@vger.kernel.org Cc: anshuman.khandual@arm.com, ardb@kernel.org, Andrew Morton , Yury Norov , Rasmus Villemoes , Arnd Bergmann , linux-arch@vger.kernel.org Subject: [PATCH V3 2/2] lib/test_bits.c: Add tests for GENMASK_U128() Date: Thu, 1 Aug 2024 12:46:46 +0530 Message-Id: <20240801071646.682731-3-anshuman.khandual@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240801071646.682731-1-anshuman.khandual@arm.com> References: <20240801071646.682731-1-anshuman.khandual@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" This adds GENMASK_U128() tests although currently only 64 bit wide masks are being tested. Cc: Andrew Morton Cc: linux-kernel@vger.kernel.org Reviewed-by: Arnd Bergmann Signed-off-by: Anshuman Khandual Reviewed-by: Yury Norov --- lib/test_bits.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/lib/test_bits.c b/lib/test_bits.c index 01313980f175..d3d858b24e02 100644 --- a/lib/test_bits.c +++ b/lib/test_bits.c @@ -39,6 +39,26 @@ static void genmask_ull_test(struct kunit *test) #endif } =20 +static void genmask_u128_test(struct kunit *test) +{ +#ifdef CONFIG_ARCH_SUPPORTS_INT128 + /* Tests mask generation only when the mask width is within 64 bits */ + KUNIT_EXPECT_EQ(test, 0x0000000000ff0000ULL, GENMASK_U128(87, 80) >> 64); + KUNIT_EXPECT_EQ(test, 0x0000000000ffffffULL, GENMASK_U128(87, 64) >> 64); + KUNIT_EXPECT_EQ(test, 0x0000000000000001ULL, GENMASK_U128(0, 0)); + KUNIT_EXPECT_EQ(test, 0xffffffffffffffffULL, GENMASK_U128(63, 0)); + KUNIT_EXPECT_EQ(test, 0xffffffffffffffffULL, GENMASK_U128(64, 0) >> 1); + KUNIT_EXPECT_EQ(test, 0x00000000ffffffffULL, GENMASK_U128(81, 50) >> 50); + +#ifdef TEST_GENMASK_FAILURES + /* these should fail compilation */ + GENMASK_U128(0, 1); + GENMASK_U128(0, 10); + GENMASK_U128(9, 10); +#endif /* TEST_GENMASK_FAILURES */ +#endif /* CONFIG_ARCH_SUPPORTS_INT128 */ +} + static void genmask_input_check_test(struct kunit *test) { unsigned int x, y; @@ -56,12 +76,15 @@ static void genmask_input_check_test(struct kunit *test) /* Valid input */ KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(1, 1)); KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(39, 21)); + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(100, 80)); + KUNIT_EXPECT_EQ(test, 0, GENMASK_INPUT_CHECK(110, 65)); } =20 =20 static struct kunit_case bits_test_cases[] =3D { KUNIT_CASE(genmask_test), KUNIT_CASE(genmask_ull_test), + KUNIT_CASE(genmask_u128_test), KUNIT_CASE(genmask_input_check_test), {} }; --=20 2.30.2