From: "Luck, Tony" <tony.luck@intel.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
hdegoede@redhat.com, markgross@kernel.org, mingo@redhat.com,
bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org,
hpa@zytor.com, corbet@lwn.net, gregkh@linuxfoundation.org,
andriy.shevchenko@linux.intel.com, jithu.joseph@intel.com,
ashok.raj@intel.com, rostedt@goodmis.org,
dan.j.williams@intel.com, linux-kernel@vger.kernel.org,
linux-doc@vger.kernel.org, platform-driver-x86@vger.kernel.org,
patches@lists.linux.dev, ravi.v.shankar@intel.com
Subject: Re: [PATCH v5 07/10] platform/x86/intel/ifs: Add scan test support
Date: Thu, 5 May 2022 11:32:04 -0700 [thread overview]
Message-ID: <YnQYJIVC0scuL7D7@agluck-desk3.sc.intel.com> (raw)
In-Reply-To: <87bkwcic9k.ffs@tglx>
On Thu, May 05, 2022 at 11:01:27AM +0200, Thomas Gleixner wrote:
> On Thu, May 05 2022 at 10:28, Peter Zijlstra wrote:
> > On Thu, May 05, 2022 at 01:15:07AM +0200, Thomas Gleixner wrote:
> >> We don't have stomp_cpumask() today, but that's trivial enough to
> >> implement.
> >
> > I don't think we want to gift people a random cpumask stop_machine(),
>
> Fair enough.
>
> > but here's one that stops a core. It runs the @fn on every cpu since I
> > thought to have understood that was the requirement for this muck.
>
> Yes.
>
> > *completely* untestededed.
>
> Looks about right neverthelessesseess.
Close enough. I made these changes:
1) Added EXPORT_SYMBOL_GPL()
2) Added protoype in <linux/stop_machine.h>
3) Moved the kerneldoc comment to the header (for some reason
the other stop* functions document there).
4) Edited that kerneldoc a bit <<<< NEEDS REVIEW >>>
5) Changed a ';' to a ',' to make it compile.
With that it works, and will do exactly what I need (with less code
in the IFS driver by the look of things).
A couple of thousand tests shows it works. The two threads
arrive within 20 TSC cycles of each other 60% of the time,
but I have some outliers up to 654 cycles ... which is plenty
close enough.
Patch now looks like this. Author credit to Peter ... are you willing
to add a Signed-off-by to stop checkpatch from whining at me?
There isn't a "Something-similar-suggested-by:" tag to credit Thomas
with this. Perhaps "Inspired-by:"?
-Tony
From df5ca8024997d3d782978d154cfbff5147f451ad Mon Sep 17 00:00:00 2001
From: Peter Zijlstra <peterz@infradead.org>
Date: Thu, 5 May 2022 08:55:09 -0700
Subject: [PATCH] stop_machine: Add stop_core_cpuslocked() for per-core
operations
Hardware core level testing features require near simultaneous execution
of WRMSR instructions on all threads of a core to initiate a test.
Provide a customized cut down version of stop_machine_cpuslocked() that
just operates on the threads of a single core.
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
include/linux/stop_machine.h | 16 ++++++++++++++++
kernel/stop_machine.c | 19 +++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/include/linux/stop_machine.h b/include/linux/stop_machine.h
index 46fb3ebdd16e..ea7a74ea7389 100644
--- a/include/linux/stop_machine.h
+++ b/include/linux/stop_machine.h
@@ -124,6 +124,22 @@ int stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus);
*/
int stop_machine_cpuslocked(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus);
+/**
+ * stop_core_cpuslocked: - stop all threads on just one core
+ * @cpu: any cpu in the targeted core
+ * @fn: the function to run
+ * @data: the data ptr for @fn()
+ *
+ * Same as above, but instead of every CPU, only the logical CPUs of a
+ * single core are affected.
+ *
+ * Context: Must be called from within a cpus_read_lock() protected region.
+ *
+ * Return: 0 if all executions of @fn returned 0, any non zero return
+ * value if any returned non zero.
+ */
+int stop_core_cpuslocked(unsigned int cpu, cpu_stop_fn_t fn, void *data);
+
int stop_machine_from_inactive_cpu(cpu_stop_fn_t fn, void *data,
const struct cpumask *cpus);
#else /* CONFIG_SMP || CONFIG_HOTPLUG_CPU */
diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index cbc30271ea4d..579761729836 100644
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -633,6 +633,25 @@ int stop_machine(cpu_stop_fn_t fn, void *data, const struct cpumask *cpus)
}
EXPORT_SYMBOL_GPL(stop_machine);
+int stop_core_cpuslocked(unsigned int cpu, cpu_stop_fn_t fn, void *data)
+{
+ const struct cpumask *smt_mask = cpu_smt_mask(cpu);
+
+ struct multi_stop_data msdata = {
+ .fn = fn,
+ .data = data,
+ .num_threads = cpumask_weight(smt_mask),
+ .active_cpus = smt_mask,
+ };
+
+ lockdep_assert_cpus_held();
+
+ /* Set the initial state and stop all online cpus. */
+ set_state(&msdata, MULTI_STOP_PREPARE);
+ return stop_cpus(smt_mask, multi_cpu_stop, &msdata);
+}
+EXPORT_SYMBOL_GPL(stop_core_cpuslocked);
+
/**
* stop_machine_from_inactive_cpu - stop_machine() from inactive CPU
* @fn: the function to run
--
2.35.1
next prev parent reply other threads:[~2022-05-05 18:39 UTC|newest]
Thread overview: 152+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-07 19:13 [PATCH v2 00/10] Introduce In Field Scan driver Jithu Joseph
2022-04-07 19:13 ` [PATCH v2 01/10] x86/microcode/intel: expose collect_cpu_info_early() for IFS Jithu Joseph
2022-04-08 8:34 ` Borislav Petkov
2022-04-21 14:56 ` Thomas Gleixner
2022-04-07 19:13 ` [PATCH v2 02/10] Documentation: In-Field Scan Jithu Joseph
2022-04-07 19:13 ` [PATCH v2 03/10] platform/x86/intel/ifs: Add driver for " Jithu Joseph
2022-04-07 19:13 ` [PATCH v2 04/10] platform/x86/intel/ifs: Load IFS Image Jithu Joseph
2022-04-08 5:02 ` Greg KH
2022-04-08 5:04 ` Greg KH
2022-04-07 19:13 ` [PATCH v2 05/10] platform/x86/intel/ifs: Check IFS Image sanity Jithu Joseph
2022-04-07 19:13 ` [PATCH v2 06/10] platform/x86/intel/ifs: Authenticate and copy to secured memory Jithu Joseph
2022-04-07 19:13 ` [PATCH v2 07/10] platform/x86/intel/ifs: Add scan test support Jithu Joseph
2022-04-07 19:13 ` [PATCH v2 08/10] platform/x86/intel/ifs: Add IFS sysfs interface Jithu Joseph
2022-04-08 4:59 ` Greg KH
2022-04-07 19:13 ` [PATCH v2 09/10] platform/x86/intel/ifs: add ABI documentation for IFS Jithu Joseph
2022-04-08 5:02 ` Greg KH
2022-04-07 19:13 ` [PATCH v2 10/10] trace: platform/x86/intel/ifs: Add trace point to track Intel IFS operations Jithu Joseph
2022-04-19 16:38 ` [PATCH v3 00/11] Introduce In Field Scan driver Tony Luck
2022-04-19 16:38 ` [PATCH v3 01/11] x86/microcode/intel: Expose collect_cpu_info_early() for IFS Tony Luck
2022-04-19 16:38 ` [PATCH v3 02/11] Documentation: In-Field Scan Tony Luck
2022-04-19 16:48 ` Greg KH
2022-04-19 19:45 ` Dan Williams
2022-04-20 7:48 ` Greg KH
2022-04-19 16:38 ` [PATCH v3 03/11] platform/x86/intel/ifs: Create device for Intel IFS (In Field Scan) Tony Luck
2022-04-19 16:47 ` Greg KH
2022-04-19 18:09 ` Dan Williams
2022-04-19 22:28 ` Dan Williams
2022-04-20 7:49 ` Greg KH
2022-04-20 7:48 ` Greg KH
2022-04-20 15:27 ` Luck, Tony
2022-04-20 17:46 ` Greg KH
2022-04-20 17:57 ` Luck, Tony
2022-04-20 18:04 ` Greg KH
2022-04-20 18:08 ` Luck, Tony
2022-04-20 19:04 ` Greg KH
2022-04-19 16:38 ` [PATCH v3 04/11] platform/x86/intel/ifs: Add stub driver for In-Field Scan Tony Luck
2022-04-19 16:38 ` [PATCH v3 05/11] platform/x86/intel/ifs: Read IFS firmware image Tony Luck
2022-04-19 17:14 ` Greg KH
2022-04-19 16:38 ` [PATCH v3 06/11] platform/x86/intel/ifs: Check IFS Image sanity Tony Luck
2022-04-19 17:16 ` Greg KH
2022-04-19 16:38 ` [PATCH v3 07/11] platform/x86/intel/ifs: Authenticate and copy to secured memory Tony Luck
2022-04-19 16:38 ` [PATCH v3 08/11] platform/x86/intel/ifs: Add scan test support Tony Luck
2022-04-19 16:38 ` [PATCH v3 09/11] platform/x86/intel/ifs: Add IFS sysfs interface Tony Luck
2022-04-19 17:20 ` Greg KH
2022-04-19 17:35 ` Luck, Tony
2022-04-19 17:58 ` Greg KH
2022-04-19 18:15 ` Dan Williams
2022-04-19 18:24 ` Dan Williams
2022-04-19 16:38 ` [PATCH v3 10/11] trace: platform/x86/intel/ifs: Add trace point to track Intel IFS operations Tony Luck
2022-04-20 23:38 ` Steven Rostedt
2022-04-21 4:26 ` Luck, Tony
2022-04-21 12:41 ` Steven Rostedt
2022-04-19 16:38 ` [PATCH v3 11/11] platform/x86/intel/ifs: add ABI documentation for IFS Tony Luck
2022-04-22 20:02 ` [PATCH v4 00/10] Introduce In Field Scan driver Tony Luck
2022-04-22 20:02 ` [PATCH v4 01/10] x86/microcode/intel: Expose collect_cpu_info_early() for IFS Tony Luck
2022-04-22 20:02 ` [PATCH v4 02/10] x86/msr-index: Define INTEGRITY_CAPABILITIES MSR Tony Luck
2022-04-22 20:02 ` [PATCH v4 03/10] platform/x86/intel/ifs: Add stub driver for In-Field Scan Tony Luck
2022-04-22 20:02 ` [PATCH v4 04/10] platform/x86/intel/ifs: Read IFS firmware image Tony Luck
2022-04-26 10:45 ` Greg KH
2022-04-26 16:12 ` Luck, Tony
2022-04-26 16:36 ` Greg KH
2022-04-26 18:47 ` Luck, Tony
2022-04-22 20:02 ` [PATCH v4 05/10] platform/x86/intel/ifs: Check IFS Image sanity Tony Luck
2022-04-22 20:02 ` [PATCH v4 06/10] platform/x86/intel/ifs: Authenticate and copy to secured memory Tony Luck
2022-04-22 20:02 ` [PATCH v4 07/10] platform/x86/intel/ifs: Add scan test support Tony Luck
2022-04-22 20:02 ` [PATCH v4 08/10] platform/x86/intel/ifs: Add IFS sysfs interface Tony Luck
2022-04-22 20:02 ` [PATCH v4 09/10] trace: platform/x86/intel/ifs: Add trace point to track Intel IFS operations Tony Luck
2022-04-25 14:52 ` Steven Rostedt
2022-04-25 16:49 ` Luck, Tony
2022-04-26 1:49 ` Steven Rostedt
2022-04-26 23:53 ` Luck, Tony
2022-04-27 2:42 ` Steven Rostedt
2022-04-22 20:02 ` [PATCH v4 10/10] platform/x86/intel/ifs: add ABI documentation for IFS Tony Luck
2022-04-28 15:38 ` [PATCH v5 00/10] Introduce In Field Scan driver Tony Luck
2022-04-28 15:38 ` [PATCH v5 01/10] x86/microcode/intel: Expose collect_cpu_info_early() for IFS Tony Luck
2022-05-03 15:29 ` Borislav Petkov
2022-05-04 10:28 ` Thomas Gleixner
2022-04-28 15:38 ` [PATCH v5 02/10] x86/msr-index: Define INTEGRITY_CAPABILITIES MSR Tony Luck
2022-04-28 15:38 ` [PATCH v5 03/10] platform/x86/intel/ifs: Add stub driver for In-Field Scan Tony Luck
2022-05-04 10:35 ` Thomas Gleixner
2022-05-04 16:24 ` Luck, Tony
2022-05-04 16:28 ` Borislav Petkov
2022-04-28 15:38 ` [PATCH v5 04/10] platform/x86/intel/ifs: Read IFS firmware image Tony Luck
2022-05-04 10:37 ` Thomas Gleixner
2022-05-04 16:49 ` Luck, Tony
2022-04-28 15:38 ` [PATCH v5 05/10] platform/x86/intel/ifs: Check IFS Image sanity Tony Luck
2022-04-28 15:38 ` [PATCH v5 06/10] platform/x86/intel/ifs: Authenticate and copy to secured memory Tony Luck
2022-05-04 10:48 ` Thomas Gleixner
2022-04-28 15:38 ` [PATCH v5 07/10] platform/x86/intel/ifs: Add scan test support Tony Luck
2022-05-04 12:29 ` Thomas Gleixner
2022-05-04 18:52 ` Luck, Tony
2022-05-04 23:15 ` Thomas Gleixner
2022-05-05 8:28 ` Peter Zijlstra
2022-05-05 9:01 ` Thomas Gleixner
2022-05-05 18:32 ` Luck, Tony [this message]
2022-05-05 20:21 ` Peter Zijlstra
2022-04-28 15:38 ` [PATCH v5 08/10] platform/x86/intel/ifs: Add IFS sysfs interface Tony Luck
2022-04-28 15:38 ` [PATCH v5 09/10] trace: platform/x86/intel/ifs: Add trace point to track Intel IFS operations Tony Luck
2022-04-28 15:38 ` [PATCH v5 10/10] platform/x86/intel/ifs: add ABI documentation for IFS Tony Luck
2022-04-28 15:58 ` [PATCH v5 00/10] Introduce In Field Scan driver Greg KH
2022-04-28 16:07 ` Luck, Tony
2022-05-02 15:15 ` Hans de Goede
2022-05-02 17:23 ` Luck, Tony
2022-05-03 15:32 ` Borislav Petkov
2022-05-03 16:04 ` Luck, Tony
2022-05-03 16:26 ` Luck, Tony
2022-05-06 14:19 ` Hans de Goede
2022-05-06 15:53 ` Luck, Tony
2022-05-06 18:41 ` Hans de Goede
2022-05-09 17:05 ` Luck, Tony
2022-05-09 18:12 ` Hans de Goede
2022-05-06 1:40 ` [PATCH v6 00/11] " Tony Luck
2022-05-06 1:40 ` [PATCH v6 01/11] x86/microcode/intel: Expose collect_cpu_info_early() for IFS Tony Luck
2022-05-06 1:40 ` [PATCH v6 02/11] x86/msr-index: Define INTEGRITY_CAPABILITIES MSR Tony Luck
2022-05-06 8:19 ` Thomas Gleixner
2022-05-06 1:40 ` [PATCH v6 03/11] stop_machine: Add stop_core_cpuslocked() for per-core operations Tony Luck
2022-05-06 8:20 ` Thomas Gleixner
2022-05-06 1:40 ` [PATCH v6 04/11] platform/x86/intel/ifs: Add stub driver for In-Field Scan Tony Luck
2022-05-06 8:23 ` Thomas Gleixner
2022-05-06 1:40 ` [PATCH v6 05/11] platform/x86/intel/ifs: Read IFS firmware image Tony Luck
2022-05-06 1:40 ` [PATCH v6 06/11] platform/x86/intel/ifs: Check IFS Image sanity Tony Luck
2022-05-06 1:40 ` [PATCH v6 07/11] platform/x86/intel/ifs: Authenticate and copy to secured memory Tony Luck
2022-05-06 1:40 ` [PATCH v6 08/11] platform/x86/intel/ifs: Add scan test support Tony Luck
2022-05-06 13:30 ` Thomas Gleixner
2022-05-06 18:49 ` Luck, Tony
2022-05-06 19:06 ` Thomas Gleixner
2022-05-06 1:40 ` [PATCH v6 09/11] platform/x86/intel/ifs: Add IFS sysfs interface Tony Luck
2022-05-06 1:40 ` [PATCH v6 10/11] trace: platform/x86/intel/ifs: Add trace point to track Intel IFS operations Tony Luck
2022-05-06 1:40 ` [PATCH v6 11/11] platform/x86/intel/ifs: add ABI documentation for IFS Tony Luck
2022-05-06 22:53 ` [PATCH v7 00/12] Introduce In Field Scan driver Tony Luck
2022-05-06 22:53 ` [PATCH v7 01/12] x86/microcode/intel: Expose collect_cpu_info_early() for IFS Tony Luck
2022-05-06 22:54 ` [PATCH v7 02/12] x86/msr-index: Define INTEGRITY_CAPABILITIES MSR Tony Luck
2022-05-06 22:54 ` [PATCH v7 03/12] stop_machine: Add stop_core_cpuslocked() for per-core operations Tony Luck
2022-05-06 22:54 ` [PATCH v7 04/12] platform/x86/intel/ifs: Add stub driver for In-Field Scan Tony Luck
2022-05-06 22:54 ` [PATCH v7 05/12] platform/x86/intel/ifs: Read IFS firmware image Tony Luck
2022-05-09 12:11 ` Thomas Gleixner
2022-05-06 22:54 ` [PATCH v7 06/12] platform/x86/intel/ifs: Check IFS Image sanity Tony Luck
2022-05-09 12:11 ` Thomas Gleixner
2022-05-09 16:31 ` Borislav Petkov
2022-05-09 16:51 ` Luck, Tony
2022-05-09 16:56 ` Borislav Petkov
2022-05-06 22:54 ` [PATCH v7 07/12] platform/x86/intel/ifs: Authenticate and copy to secured memory Tony Luck
2022-05-09 12:11 ` Thomas Gleixner
2022-05-06 22:54 ` [PATCH v7 08/12] platform/x86/intel/ifs: Add scan test support Tony Luck
2022-05-09 12:11 ` Thomas Gleixner
2022-05-06 22:54 ` [PATCH v7 09/12] platform/x86/intel/ifs: Add IFS sysfs interface Tony Luck
2022-05-09 12:12 ` Thomas Gleixner
2022-05-06 22:54 ` [PATCH v7 10/12] trace: platform/x86/intel/ifs: Add trace point to track Intel IFS operations Tony Luck
2022-05-06 22:54 ` [PATCH v7 11/12] platform/x86/intel/ifs: add ABI documentation for IFS Tony Luck
2022-05-06 22:54 ` [PATCH v7 12/12] Documentation: In-Field Scan Tony Luck
2022-05-09 12:16 ` Thomas Gleixner
2022-05-11 15:51 ` [PATCH v7 00/12] Introduce In Field Scan driver Hans de Goede
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