From: Fenghua Yu <fenghua.yu@intel.com>
To: "Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>, "H Peter Anvin" <hpa@zytor.com>,
"Dave Hansen" <dave.hansen@intel.com>,
"Ashok Raj" <ashok.raj@intel.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Michael Chan" <michael.chan@broadcom.com>,
"Ravi V Shankar" <ravi.v.shankar@intel.com>,
"Ricardo Neri" <ricardo.neri@intel.com>
Cc: "linux-kernel" <linux-kernel@vger.kernel.org>,
"x86" <x86@kernel.org>, Fenghua Yu <fenghua.yu@intel.com>
Subject: [PATCH v3 06/10] x86/clearcpuid: Support feature flag string in kernel option clearcpuid
Date: Fri, 1 Feb 2019 21:14:47 -0800 [thread overview]
Message-ID: <1549084491-57808-7-git-send-email-fenghua.yu@intel.com> (raw)
In-Reply-To: <1549084491-57808-1-git-send-email-fenghua.yu@intel.com>
The kernel option clearcpuid currently only takes feature bit which
can be changed from kernel to kernel.
Extend clearcpuid to use cap flag string, which is defined in
x86_cap_flags[] and won't be changed from kernel to kernel.
And user can easily get the cap flag string from /proc/cpuinfo.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
arch/x86/include/asm/cpufeature.h | 1 +
arch/x86/kernel/cpu/cpuid-deps.c | 26 ++++++++++++++++++++++++++
arch/x86/kernel/fpu/init.c | 3 ++-
3 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index ce95b8cbd229..6792088525e3 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -132,6 +132,7 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
extern void setup_clear_cpu_cap(unsigned int bit);
extern void clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit);
+bool find_cpu_cap(char *cap_flag, unsigned int *pfeature);
#define setup_force_cpu_cap(bit) do { \
set_cpu_cap(&boot_cpu_data, bit); \
diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index 2c0bd38a44ab..19bfab0858ac 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -119,3 +119,29 @@ void setup_clear_cpu_cap(unsigned int feature)
{
do_clear_cpu_cap(NULL, feature);
}
+
+/**
+ * find_cpu_cap - Given a cap flag string, find its corresponding feature bit.
+ * @cap_flag: cap flag string as defined in x86_cap_flags[]
+ * @pfeature: feature bit
+ *
+ * Return: true if the feature is found. false if not found
+ */
+bool find_cpu_cap(char *cap_flag, unsigned int *pfeature)
+{
+#ifdef CONFIG_X86_FEATURE_NAMES
+ unsigned int feature;
+
+ for (feature = 0; feature < NCAPINTS * 32; feature++) {
+ if (!x86_cap_flags[feature])
+ continue;
+
+ if (strcmp(cap_flag, x86_cap_flags[feature]) == 0) {
+ *pfeature = feature;
+
+ return true;
+ }
+ }
+#endif
+ return false;
+}
diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index da92f7f340c1..a9a67645a607 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -261,7 +261,8 @@ static void __init setup_cpuid_option(char *setup_cpuid_option)
/* Chang command line range for next search. */
cmdline_size = option_pos - boot_command_line + 1;
argptr = arg;
- if (get_option(&argptr, &bit) &&
+ /* cpu cap can be specified by either feature bit or string */
+ if ((get_option(&argptr, &bit) || find_cpu_cap(arg, &bit)) &&
bit >= 0 && bit < NCAPINTS * 32)
setup_cpu_cap(bit);
}
--
2.7.4
next prev parent reply other threads:[~2019-02-02 5:21 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-02 5:14 [PATCH v3 00/10] x86/split_lock: Enable #AC exception for split locked accesses Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 01/10] x86/common: Align cpu_caps_cleared and cpu_caps_set to unsigned long Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 02/10] drivers/net/b44: Align pwol_mask to unsigned long for better performance Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 03/10] wlcore: Align reg_ch_conf_pending and tmp_ch_bitmap " Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 04/10] x86/split_lock: Align x86_capability to unsigned long to avoid split locked access Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 05/10] x86/clearcpuid: Support multiple clearcpuid options Fenghua Yu
2019-02-02 5:14 ` Fenghua Yu [this message]
2019-02-02 5:14 ` [PATCH v3 07/10] Change document for kernel option clearcpuid Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 08/10] x86/setcpuid: Add kernel option setcpuid Fenghua Yu
2019-02-04 17:49 ` Thomas Gleixner
2019-02-04 19:05 ` Dave Hansen
2019-02-04 19:57 ` Borislav Petkov
2019-02-04 20:46 ` Dave Hansen
2019-02-04 21:40 ` Borislav Petkov
2019-02-04 22:14 ` Fenghua Yu
2019-02-05 6:10 ` Borislav Petkov
2019-02-04 23:24 ` Dave Hansen
2019-02-05 6:18 ` Borislav Petkov
2019-02-05 16:46 ` Dave Hansen
2019-02-05 17:09 ` Peter Zijlstra
2019-02-05 8:57 ` Peter Zijlstra
2019-02-05 13:15 ` Peter Zijlstra
2019-02-05 8:48 ` Peter Zijlstra
2019-02-05 15:19 ` Dave Hansen
2019-02-05 15:43 ` Borislav Petkov
2019-02-05 18:26 ` Fenghua Yu
2019-02-05 17:04 ` Peter Zijlstra
2019-02-10 19:20 ` Thomas Gleixner
2019-02-11 19:16 ` Fenghua Yu
2019-02-12 13:37 ` Peter Zijlstra
2019-02-12 13:51 ` Thomas Gleixner
2019-02-12 16:48 ` Peter Zijlstra
2019-02-12 16:50 ` Dave Hansen
2019-02-12 17:52 ` Yu, Fenghua
2019-02-04 21:09 ` Fenghua Yu
2019-02-05 8:51 ` Peter Zijlstra
2019-02-05 15:21 ` Dave Hansen
2019-02-05 15:34 ` Peter Zijlstra
2019-02-02 5:14 ` [PATCH v3 09/10] x86/split_lock: Define #AC for split lock feature Fenghua Yu
2019-02-04 18:41 ` Dave Hansen
2019-02-04 18:45 ` Fenghua Yu
2019-02-04 19:00 ` Dave Hansen
2019-02-04 19:03 ` Fenghua Yu
2019-02-02 5:14 ` [PATCH v3 10/10] x86/split_lock: Handle #AC exception for split lock Fenghua Yu
2019-02-04 11:00 ` kbuild test robot
2019-02-04 14:43 ` kbuild test robot
2019-02-11 10:53 ` Ingo Molnar
2019-02-11 18:10 ` Fenghua Yu
2019-02-13 8:14 ` Ingo Molnar
2019-02-13 14:37 ` Yu, Fenghua
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