From: Andy Lutomirski <luto@kernel.org>
To: x86@kernel.org, linux-kernel@vger.kernel.org
Cc: Borislav Petkov <bp@alien8.de>, Brian Gerst <brgerst@gmail.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Oleg Nesterov <oleg@redhat.com>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
Andy Lutomirski <luto@kernel.org>
Subject: [RFC 06/13] x86/mm: Disable PCID on 32-bit kernels
Date: Fri, 8 Jan 2016 15:15:24 -0800 [thread overview]
Message-ID: <a68c8eb9183aa633c5c976a58120ee0a64f75563.1452294700.git.luto@kernel.org> (raw)
In-Reply-To: <cover.1452294700.git.luto@kernel.org>
In-Reply-To: <cover.1452294700.git.luto@kernel.org>
32-bit kernels on new hardware will see PCID in CPUID, but PCID can
only be used in 64-bit mode. Rather than making all PCID code
conditional, just disable the feature on 32-bit builds.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
arch/x86/include/asm/disabled-features.h | 4 +++-
arch/x86/kernel/cpu/bugs.c | 6 ++++++
2 files changed, 9 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h
index f226df064660..8b17c2ad1048 100644
--- a/arch/x86/include/asm/disabled-features.h
+++ b/arch/x86/include/asm/disabled-features.h
@@ -21,11 +21,13 @@
# define DISABLE_K6_MTRR (1<<(X86_FEATURE_K6_MTRR & 31))
# define DISABLE_CYRIX_ARR (1<<(X86_FEATURE_CYRIX_ARR & 31))
# define DISABLE_CENTAUR_MCR (1<<(X86_FEATURE_CENTAUR_MCR & 31))
+# define DISABLE_PCID 0
#else
# define DISABLE_VME 0
# define DISABLE_K6_MTRR 0
# define DISABLE_CYRIX_ARR 0
# define DISABLE_CENTAUR_MCR 0
+# define DISABLE_PCID (1<<(X86_FEATURE_PCID & 31))
#endif /* CONFIG_X86_64 */
/*
@@ -35,7 +37,7 @@
#define DISABLED_MASK1 0
#define DISABLED_MASK2 0
#define DISABLED_MASK3 (DISABLE_CYRIX_ARR|DISABLE_CENTAUR_MCR|DISABLE_K6_MTRR)
-#define DISABLED_MASK4 0
+#define DISABLED_MASK4 (DISABLE_PCID)
#define DISABLED_MASK5 0
#define DISABLED_MASK6 0
#define DISABLED_MASK7 0
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index bd17db15a2c1..741d107e5376 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -19,6 +19,12 @@
void __init check_bugs(void)
{
+ /*
+ * Regardless of whether PCID is enumerated, it can't be used in
+ * 32-bit mode.
+ */
+ setup_clear_cpu_cap(X86_FEATURE_PCID);
+
identify_boot_cpu();
#ifndef CONFIG_SMP
pr_info("CPU: ");
--
2.5.0
--
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next prev parent reply other threads:[~2016-01-08 23:15 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-08 23:15 [RFC 00/13] x86/mm: PCID and INVPCID Andy Lutomirski
2016-01-08 23:15 ` [RFC 01/13] x86/paravirt: Turn KASAN off for parvirt.o Andy Lutomirski
2016-01-10 18:59 ` Borislav Petkov
2016-01-11 12:51 ` Andrey Ryabinin
2016-01-11 12:51 ` [PATCH 1/2] x86/kasan: clear kasan_zero_page after TLB flush Andrey Ryabinin
2016-01-18 22:24 ` Andy Lutomirski
2016-01-11 12:51 ` [PATCH 2/2] x86/kasan: write protect kasan zero shadow Andrey Ryabinin
2016-01-18 22:24 ` Andy Lutomirski
2016-01-29 10:35 ` [RFC 01/13] x86/paravirt: Turn KASAN off for parvirt.o Borislav Petkov
2016-01-08 23:15 ` [RFC 02/13] x86/mm: Add INVPCID helpers Andy Lutomirski
2016-01-08 23:15 ` [RFC 03/13] x86/mm: Add a noinvpcid option to turn off INVPCID Andy Lutomirski
2016-01-08 23:15 ` [RFC 04/13] x86/mm: If INVPCID is available, use it to flush global mappings Andy Lutomirski
2016-01-08 23:15 ` [RFC 05/13] x86/mm: Add barriers and document switch_mm-vs-flush synchronization Andy Lutomirski
2016-06-03 17:42 ` Nadav Amit
2016-06-09 17:24 ` Andy Lutomirski
2016-06-09 19:45 ` Nadav Amit
2016-09-06 1:22 ` Wanpeng Li
2016-01-08 23:15 ` Andy Lutomirski [this message]
2016-01-08 23:15 ` [RFC 07/13] x86/mm: Add nopcid to turn off PCID Andy Lutomirski
2016-01-08 23:15 ` [RFC 08/13] x86/mm: Teach CR3 readers about PCID Andy Lutomirski
2016-01-08 23:15 ` [RFC 09/13] x86/mm: Disable interrupts when flushing the TLB using CR3 Andy Lutomirski
2016-01-08 23:41 ` Linus Torvalds
2016-01-09 0:18 ` Andy Lutomirski
2016-01-09 2:20 ` Linus Torvalds
2016-01-11 10:51 ` Ingo Molnar
2016-01-13 23:32 ` Andy Lutomirski
2016-01-13 23:35 ` Andy Lutomirski
2016-01-13 23:43 ` Dave Hansen
2016-01-13 23:51 ` Andy Lutomirski
2016-01-13 23:56 ` Dave Hansen
2016-01-14 0:34 ` Andy Lutomirski
2016-01-08 23:15 ` [RFC 10/13] x86/mm: Factor out remote TLB flushing Andy Lutomirski
2016-01-08 23:15 ` [RFC 11/13] x86/mm: Build arch/x86/mm/tlb.c even on !SMP Andy Lutomirski
2016-01-08 23:55 ` Dave Hansen
2016-01-08 23:15 ` [RFC 12/13] x86/mm: Uninline switch_mm Andy Lutomirski
2016-01-08 23:15 ` [RFC 13/13] x86/mm: Try to preserve old TLB entries using PCID Andy Lutomirski
2016-01-09 0:27 ` Dave Hansen
2016-01-09 2:19 ` Andy Lutomirski
2016-01-08 23:31 ` [RFC 00/13] x86/mm: PCID and INVPCID Linus Torvalds
2016-01-08 23:36 ` Andy Lutomirski
2016-01-08 23:42 ` Linus Torvalds
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