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From:   Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
To:     <herbert@gondor.apana.org.au>, <davem@davemloft.net>,
        <tglx@linutronix.de>, <mingo@redhat.com>, <bp@alien8.de>,
        <x86@kernel.org>, <hpa@zytor.com>, <linux-crypto@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     <TimGuo-oc@zhaoxin.com>, <CooperYan@zhaoxin.com>,
        <QiyuanWang@zhaoxin.com>, <HerryYang@zhaoxin.com>,
        <CobeChen@zhaoxin.com>, <SilviaZhao@zhaoxin.com>
Subject: [PATCH] crypto: x86/crc32c-intel - Don't match some Zhaoxin CPUs
Date:   Fri, 11 Dec 2020 19:29:04 +0800
Message-ID: <1607686144-2604-1-git-send-email-TonyWWang-oc@zhaoxin.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

The driver crc32c-intel match CPUs supporting X86_FEATURE_XMM4_2.
On platforms with Zhaoxin CPUs supporting this X86 feature, When
crc32c-intel and crc32c-generic are both registered, system will
use crc32c-intel because its .cra_priority is greater than
crc32c-generic. This case expect to use crc32c-generic driver for
some Zhaoxin CPUs to get performance gain, So remove these Zhaoxin
CPUs support from crc32c-intel.

Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
---
 arch/x86/crypto/crc32c-intel_glue.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/x86/crypto/crc32c-intel_glue.c b/arch/x86/crypto/crc32c-intel_glue.c
index feccb52..6dafdae 100644
--- a/arch/x86/crypto/crc32c-intel_glue.c
+++ b/arch/x86/crypto/crc32c-intel_glue.c
@@ -222,8 +222,16 @@ MODULE_DEVICE_TABLE(x86cpu, crc32c_cpu_id);
 
 static int __init crc32c_intel_mod_init(void)
 {
+	struct cpuinfo_x86 *c = &boot_cpu_data;
+
 	if (!x86_match_cpu(crc32c_cpu_id))
 		return -ENODEV;
+
+	if (c->x86_vendor == X86_VENDOR_ZHAOXIN || c->x86_vendor == X86_VENDOR_CENTAUR) {
+		if (c->x86 == 0x6 || (c->x86 == 0x7 && c->x86_model <= 0x3b))
+			return -ENODEV;
+	}
+
 #ifdef CONFIG_X86_64
 	if (boot_cpu_has(X86_FEATURE_PCLMULQDQ)) {
 		alg.update = crc32c_pcl_intel_update;
-- 
2.7.4