From: Borislav Petkov <bp@alien8.de>
To: X86 ML <x86@kernel.org>
Cc: Sherry Hurwitz <sherry.hurwitz@amd.com>,
LKML <linux-kernel@vger.kernel.org>
Subject: [PATCH] x86/AMD: Fix erratum 1076 (CPB bit)
Date: Thu, 7 Sep 2017 19:08:21 +0200 [thread overview]
Message-ID: <20170907170821.16021-1-bp@alien8.de> (raw)
From: Borislav Petkov <bp@suse.de>
CPUID Fn8000_0007_EDX[CPB] is wrongly 0 on models up to B1. But they do
support CPB so fix that.
Signed-off-by: Borislav Petkov <bp@suse.de>
---
arch/x86/kernel/cpu/amd.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 9862e2cd6d93..d58184b7cd44 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -763,6 +763,16 @@ static void init_amd_bd(struct cpuinfo_x86 *c)
}
}
+static void init_amd_zn(struct cpuinfo_x86 *c)
+{
+ /*
+ * Fix erratum 1076: CPB feature bit not being set in CPUID. It affects
+ * all up to and including B1.
+ */
+ if (c->x86_model <= 1 && c->x86_mask <= 1)
+ set_cpu_cap(c, X86_FEATURE_CPB);
+}
+
static void init_amd(struct cpuinfo_x86 *c)
{
early_init_amd(c);
@@ -791,6 +801,7 @@ static void init_amd(struct cpuinfo_x86 *c)
case 0x10: init_amd_gh(c); break;
case 0x12: init_amd_ln(c); break;
case 0x15: init_amd_bd(c); break;
+ case 0x17: init_amd_zn(c); break;
}
/* Enable workaround for FXSAVE leak */
--
2.13.0
next reply other threads:[~2017-09-07 17:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-07 17:08 Borislav Petkov [this message]
2017-09-15 8:45 ` [tip:x86/urgent] x86/cpu/AMD: Fix erratum 1076 (CPB bit) tip-bot for Borislav Petkov
2017-09-15 9:33 ` tip-bot for Borislav Petkov
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=20170907170821.16021-1-bp@alien8.de \
--to=bp@alien8.de \
--cc=linux-kernel@vger.kernel.org \
--cc=sherry.hurwitz@amd.com \
--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;
as well as URLs for NNTP newsgroup(s).