From: Fenghua Yu <fenghua.yu@intel.com>
To: "Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@elte.hu>,
"H. Peter Anvin" <hpa@linux.intel.com>
Cc: "Ashok Raj" <ashok.raj@intel.com>,
"Dave Hansen" <dave.hansen@intel.com>,
"Rafael Wysocki" <rafael.j.wysocki@intel.com>,
"Tony Luck" <tony.luck@intel.com>,
"Alan Cox" <alan@linux.intel.com>,
"Ravi V Shankar" <ravi.v.shankar@intel.com>,
"Arjan van de Ven" <arjan@infradead.org>,
"linux-kernel" <linux-kernel@vger.kernel.org>,
"x86" <x86@kernel.org>, Fenghua Yu <fenghua.yu@intel.com>
Subject: [RFC PATCH 09/16] x86/split_lock: Add CONFIG to control #AC for split lock at boot time
Date: Sun, 27 May 2018 08:45:58 -0700 [thread overview]
Message-ID: <1527435965-202085-10-git-send-email-fenghua.yu@intel.com> (raw)
In-Reply-To: <1527435965-202085-1-git-send-email-fenghua.yu@intel.com>
User wants to specify how to set up #AC for split lock at boot time.
CONFIG_SPLIT_LOCK_AC_ENABLE_DEFAULT is added to control split
lock setting at boot time.
Default value is 2: Don't explicitly enable or disable #AC for split lock.
Inherit setting of #AC for split lock from firmware.
Value 0 to explicitly disable split lock at boot time.
Value 1 to explicitly enable split lock at boot time.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
arch/x86/Kconfig | 14 ++++++++++++++
arch/x86/kernel/cpu/test_ctl.c | 12 ++++++++++++
2 files changed, 26 insertions(+)
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 043cde9a9b08..1d0dcd6fa69a 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -461,6 +461,20 @@ config SPLIT_LOCK_AC
Say N if unsure.
+config SPLIT_LOCK_AC_ENABLE_DEFAULT
+ int "#AC for split lock enable value (0-2) at boot time"
+ range 0 2
+ default "2"
+ depends on SPLIT_LOCK_AC
+ help
+ Set #AC for split lock enable default value at boot time
+ 0: Explicitly disable #AC for split lock at boot time.
+ 1: Explicitly enable #AC for split lock at boot time.
+ 2: Don't explicitly enable or disable #AC for split lock.
+ Inherit setting of #AC for split lock from firmware.
+
+ Leave this to the default value of 2 if you are unsure.
+
if X86_32
config X86_BIGSMP
bool "Support for big SMP systems with more than 8 CPUs"
diff --git a/arch/x86/kernel/cpu/test_ctl.c b/arch/x86/kernel/cpu/test_ctl.c
index 82440740b2b9..a2f84fcd4da1 100644
--- a/arch/x86/kernel/cpu/test_ctl.c
+++ b/arch/x86/kernel/cpu/test_ctl.c
@@ -21,6 +21,7 @@
#define DISABLE_SPLIT_LOCK_AC 0
#define ENABLE_SPLIT_LOCK_AC 1
+#define INHERIT_SPLIT_LOCK_AC_FIRMWARE 2
/* After disabling #AC for split lock in handler, re-enable it 1 msec later. */
#define reenable_split_lock_delay msecs_to_jiffies(1)
@@ -71,6 +72,17 @@ void detect_split_lock_ac(void)
split_lock_ac_firmware = ENABLE_SPLIT_LOCK_AC;
else
split_lock_ac_firmware = DISABLE_SPLIT_LOCK_AC;
+
+ /*
+ * By default configuration, kernel inherits firmware split lock
+ * setting. Kernel can be configured to explicitly enable or disable
+ * #AC for split lock to override firmware setting.
+ */
+ if (CONFIG_SPLIT_LOCK_AC_ENABLE_DEFAULT ==
+ INHERIT_SPLIT_LOCK_AC_FIRMWARE)
+ split_lock_ac_kernel = split_lock_ac_firmware;
+ else
+ split_lock_ac_kernel = CONFIG_SPLIT_LOCK_AC_ENABLE_DEFAULT;
}
static void _setup_split_lock(int split_lock_ac_val)
--
2.5.0
next prev parent reply other threads:[~2018-05-27 15:49 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-27 15:45 [RFC PATCH 00/16] x86/split_lock: Enable #AC exception for split locked accesses Fenghua Yu
2018-05-27 15:45 ` [RFC PATCH 01/16] x86/split_lock: Add CONFIG and enumerate #AC exception for split locked access feature Fenghua Yu
2018-05-27 15:45 ` [RFC PATCH 02/16] x86/split_lock: Handle #AC exception for split lock in kernel mode Fenghua Yu
2018-06-21 19:46 ` Peter Zijlstra
2018-06-22 10:49 ` Thomas Gleixner
2018-06-22 11:59 ` Thomas Gleixner
2018-06-22 22:41 ` Fenghua Yu
2018-06-22 22:57 ` Thomas Gleixner
2018-06-22 23:03 ` Thomas Gleixner
2018-06-22 23:18 ` Fenghua Yu
2018-06-23 9:08 ` Thomas Gleixner
2018-06-23 4:20 ` Fenghua Yu
2018-06-23 9:17 ` Thomas Gleixner
2018-06-23 15:05 ` Fenghua Yu
2018-06-24 0:55 ` Thomas Gleixner
2018-06-24 1:17 ` Fenghua Yu
2018-06-24 6:43 ` Thomas Gleixner
2018-05-27 15:45 ` [RFC PATCH 03/16] x86/split_lock: Set up #AC exception for split locked accesses on all CPUs Fenghua Yu
2018-05-27 15:45 ` [RFC PATCH 04/16] x86/split_lock: Use non locked bit set instruction in set_cpu_cap Fenghua Yu
2018-06-21 19:55 ` Peter Zijlstra
2018-06-21 20:37 ` Thomas Gleixner
2018-06-27 23:35 ` Fenghua Yu
2018-06-28 7:53 ` Thomas Gleixner
2018-06-28 14:23 ` Fenghua Yu
2018-06-28 14:54 ` Fenghua Yu
2018-05-27 15:45 ` [RFC PATCH 05/16] x86/split_lock: Use non atomic set and clear bit instructions in clear_cpufeature() Fenghua Yu
2018-05-27 15:45 ` [RFC PATCH 06/16] x86/split_lock: Save #AC setting for split lock in firmware in boot time and restore the setting in reboot Fenghua Yu
2018-06-21 19:58 ` Peter Zijlstra
2018-06-22 15:11 ` Alan Cox
2018-06-26 9:05 ` Peter Zijlstra
2018-06-26 9:40 ` Thomas Gleixner
2018-06-26 11:02 ` Alan Cox
2018-06-26 11:31 ` Peter Zijlstra
2018-05-27 15:45 ` [RFC PATCH 07/16] x86/split_lock: Handle suspend/hibernate and resume Fenghua Yu
2018-05-27 15:45 ` [RFC PATCH 08/16] x86/split_lock: Set split lock during EFI runtime service Fenghua Yu
2018-05-27 15:45 ` Fenghua Yu [this message]
2018-05-27 15:45 ` [RFC PATCH 10/16] x86/split_lock: Add a debugfs interface to allow user to enable or disable #AC for split lock during run time Fenghua Yu
2018-05-29 18:43 ` Greg KH
2018-05-27 15:46 ` [RFC PATCH 11/16] x86/split_lock: Add CONFIG to control #AC for split lock from kernel at boot time Fenghua Yu
2018-05-27 15:46 ` [RFC PATCH 12/16] x86/split_lock: Add a debugfs interface to allow user to change how to handle split lock in kernel mode during run time Fenghua Yu
2018-05-27 15:46 ` [RFC PATCH 13/16] x86/split_lock: Add debugfs interface to control user mode behavior Fenghua Yu
2018-05-27 15:46 ` [RFC PATCH 14/16] x86/split_lock: Add debugfs interface to show and control firmware setting for split lock Fenghua Yu
2018-05-27 15:46 ` [RFC PATCH 15/16] x86/split_lock: Add CONFIG and debugfs interface for testing #AC for split lock in kernel mode Fenghua Yu
2018-05-27 15:46 ` [RFC PATCH 16/16] x86/split_lock: Add user space split lock test in selftest Fenghua Yu
2018-05-29 16:39 ` [RFC PATCH 00/16] x86/split_lock: Enable #AC exception for split locked accesses Dave Hansen
2018-05-29 17:25 ` Fenghua Yu
2018-05-29 17:28 ` Dave Hansen
2018-05-29 17:40 ` Fenghua Yu
2018-05-29 16:40 ` Dave Hansen
2018-05-29 17:38 ` Fenghua Yu
2018-06-21 20:06 ` Peter Zijlstra
2018-06-21 19:37 ` Peter Zijlstra
2018-06-21 20:18 ` Fenghua Yu
2018-06-21 20:32 ` Thomas Gleixner
2018-06-21 22:00 ` Fenghua Yu
2018-06-21 22:07 ` Peter Zijlstra
2018-06-21 22:08 ` Peter Zijlstra
2018-06-21 22:18 ` Dave Hansen
2018-06-21 22:42 ` Fenghua Yu
2018-06-22 8:11 ` Peter Zijlstra
2018-06-22 9:30 ` Thomas Gleixner
2018-06-21 22:10 ` Peter Zijlstra
2018-06-21 23:05 ` Fenghua Yu
2018-06-22 8:19 ` Peter Zijlstra
2018-06-21 22:11 ` Peter Zijlstra
2018-06-21 22:43 ` Fenghua Yu
2018-06-21 22:13 ` Peter Zijlstra
2018-06-23 18:47 ` Fenghua Yu
2018-06-22 9:18 ` Thomas Gleixner
2018-06-22 9:22 ` Thomas Gleixner
2018-06-22 9:25 ` Thomas Gleixner
2018-06-22 9:28 ` Thomas Gleixner
2018-06-21 20:36 ` Peter Zijlstra
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