Linux cryptographic layer development
 help / color / mirror / Atom feed
From: Eric Biggers <ebiggers@kernel.org>
To: x86@kernel.org
Cc: linux-um@lists.infradead.org, linux-raid@vger.kernel.org,
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
	Christoph Hellwig <hch@lst.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	Eric Biggers <ebiggers@kernel.org>
Subject: [PATCH 5/8] lib/crc: x86: Stop using cpu_has_xfeatures()
Date: Thu, 25 Jun 2026 21:37:28 -0700	[thread overview]
Message-ID: <20260626043731.319287-6-ebiggers@kernel.org> (raw)
In-Reply-To: <20260626043731.319287-1-ebiggers@kernel.org>

Checking both boot_cpu_has() and cpu_has_xfeatures() has never really
been needed in practice, and it's never been universally done (e.g.,
lib/raid/ omits cpu_has_xfeatures()).  Nevertheless, both x86 and UML
now explicitly clear the AVX and AVX-512 flags if their xfeatures are
missing, which should remove any remaining doubts.

Thus, remove all the calls to cpu_has_xfeatures().

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
 lib/crc/x86/crc-pclmul-template.h | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/lib/crc/x86/crc-pclmul-template.h b/lib/crc/x86/crc-pclmul-template.h
index 02744831c6fa..893119bb7c07 100644
--- a/lib/crc/x86/crc-pclmul-template.h
+++ b/lib/crc/x86/crc-pclmul-template.h
@@ -25,20 +25,18 @@ crc_t prefix##_vpclmul_avx512(crc_t crc, const u8 *p, size_t len,	\
 DEFINE_STATIC_CALL(prefix##_pclmul, prefix##_pclmul_sse)
 
 static inline bool have_vpclmul(void)
 {
 	return boot_cpu_has(X86_FEATURE_VPCLMULQDQ) &&
-	       boot_cpu_has(X86_FEATURE_AVX2) &&
-	       cpu_has_xfeatures(XFEATURE_MASK_YMM, NULL);
+	       boot_cpu_has(X86_FEATURE_AVX2);
 }
 
 static inline bool have_avx512(void)
 {
 	return boot_cpu_has(X86_FEATURE_AVX512BW) &&
 	       boot_cpu_has(X86_FEATURE_AVX512VL) &&
-	       !boot_cpu_has(X86_FEATURE_PREFER_YMM) &&
-	       cpu_has_xfeatures(XFEATURE_MASK_AVX512, NULL);
+	       !boot_cpu_has(X86_FEATURE_PREFER_YMM);
 }
 
 /*
  * Call a [V]PCLMULQDQ optimized CRC function if the data length is at least 16
  * bytes, the CPU has PCLMULQDQ support, and the current context may use SIMD.
-- 
2.54.0


  parent reply	other threads:[~2026-06-26  4:39 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-06-26  4:37 [PATCH 0/8] x86: Remove cpu_has_xfeatures() and add AVX-512 xor_gen() Eric Biggers
2026-06-26  4:37 ` [PATCH 1/8] x86/fpu: Check for missing AVX and AVX-512 xstate bits Eric Biggers
2026-06-26  5:39   ` Christoph Hellwig
2026-06-26  4:37 ` [PATCH 2/8] um: " Eric Biggers
2026-06-26  7:41   ` David Laight
2026-06-26  8:21     ` Anton Ivanov
2026-06-26 10:49       ` David Laight
2026-06-26  4:37 ` [PATCH 3/8] crypto: x86 - Stop using cpu_has_xfeatures() Eric Biggers
2026-06-26  4:37 ` [PATCH 4/8] lib/crypto: x86: " Eric Biggers
2026-06-26  4:37 ` Eric Biggers [this message]
2026-06-26  4:37 ` [PATCH 6/8] x86/fpu: Remove cpu_has_xfeatures() Eric Biggers
2026-06-26  4:37 ` [PATCH 7/8] lib/raid/xor: x86: Remove redundant X86_FEATURE_OSXSAVE check Eric Biggers
2026-06-26  5:40   ` Christoph Hellwig
2026-06-26  4:37 ` [PATCH 8/8] lib/raid/xor: x86: Add AVX-512 optimized xor_gen() Eric Biggers
2026-06-26  5:47   ` Christoph Hellwig
2026-06-26  5:47     ` Christoph Hellwig

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260626043731.319287-6-ebiggers@kernel.org \
    --to=ebiggers@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=hch@lst.de \
    --cc=linux-crypto@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-raid@vger.kernel.org \
    --cc=linux-um@lists.infradead.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox