From: Yazen Ghannam <yazen.ghannam@amd.com> To: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org> Cc: "Ghannam, Yazen" <Yazen.Ghannam@amd.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "bp@suse.de" <bp@suse.de>, "tony.luck@intel.com" <tony.luck@intel.com>, "x86@kernel.org" <x86@kernel.org> Subject: [v3,6/6] x86/MCE: Treat MCE bank as initialized if control bits set in hardware Date: Tue, 30 Apr 2019 20:32:21 +0000 [thread overview] Message-ID: <20190430203206.104163-7-Yazen.Ghannam@amd.com> (raw) From: Yazen Ghannam <yazen.ghannam@amd.com> The OS is expected to write all bits to MCA_CTL for each bank. However, some banks may be unused in which case the registers for such banks are Read-as-Zero/Writes-Ignored. Also, the OS may not write any control bits because of quirks, etc. A bank can be considered uninitialized if the MCA_CTL register returns zero. This is because either the OS did not write anything or because the hardware is enforcing RAZ/WI for the bank. Set a bank's init value based on if the control bits are set or not in hardware. Return an error code in the sysfs interface for uninitialized banks. Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> --- Link: https://lkml.kernel.org/r/20190411201743.43195-7-Yazen.Ghannam@amd.com v2->v3: * No change. v1->v2: * New in v2. * Based on discussion from v1 patch 2. arch/x86/kernel/cpu/mce/core.c | 9 +++++++++ 1 file changed, 9 insertions(+) -- 2.17.1 diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 551366c155ef..e59947e10ee0 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -1574,6 +1574,9 @@ static void __mcheck_cpu_init_clear_banks(void) /* Save bits set in hardware. */ rdmsrl(msr_ops.ctl(i), b->ctl); + + /* Bank is initialized if bits are set in hardware. */ + b->init = !!b->ctl; } } @@ -2098,6 +2101,9 @@ static ssize_t show_bank(struct device *s, struct device_attribute *attr, b = &per_cpu(mce_banks_percpu, s->id)[bank]; + if (!b->init) + return -ENODEV; + return sprintf(buf, "%llx\n", b->ctl); } @@ -2116,6 +2122,9 @@ static ssize_t set_bank(struct device *s, struct device_attribute *attr, b = &per_cpu(mce_banks_percpu, s->id)[bank]; + if (!b->init) + return -ENODEV; + b->ctl = new; mce_restart();
WARNING: multiple messages have this Message-ID (diff)
From: "Ghannam, Yazen" <Yazen.Ghannam@amd.com> To: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org> Cc: "Ghannam, Yazen" <Yazen.Ghannam@amd.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, "bp@suse.de" <bp@suse.de>, "tony.luck@intel.com" <tony.luck@intel.com>, "x86@kernel.org" <x86@kernel.org> Subject: [PATCH v3 6/6] x86/MCE: Treat MCE bank as initialized if control bits set in hardware Date: Tue, 30 Apr 2019 20:32:21 +0000 [thread overview] Message-ID: <20190430203206.104163-7-Yazen.Ghannam@amd.com> (raw) Message-ID: <20190430203221.pUl2riiA5M7bDkyKvlbhgXre6SNpV0H4cBqMSBMvcLs@z> (raw) In-Reply-To: <20190430203206.104163-1-Yazen.Ghannam@amd.com> From: Yazen Ghannam <yazen.ghannam@amd.com> The OS is expected to write all bits to MCA_CTL for each bank. However, some banks may be unused in which case the registers for such banks are Read-as-Zero/Writes-Ignored. Also, the OS may not write any control bits because of quirks, etc. A bank can be considered uninitialized if the MCA_CTL register returns zero. This is because either the OS did not write anything or because the hardware is enforcing RAZ/WI for the bank. Set a bank's init value based on if the control bits are set or not in hardware. Return an error code in the sysfs interface for uninitialized banks. Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com> --- Link: https://lkml.kernel.org/r/20190411201743.43195-7-Yazen.Ghannam@amd.com v2->v3: * No change. v1->v2: * New in v2. * Based on discussion from v1 patch 2. arch/x86/kernel/cpu/mce/core.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 551366c155ef..e59947e10ee0 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -1574,6 +1574,9 @@ static void __mcheck_cpu_init_clear_banks(void) /* Save bits set in hardware. */ rdmsrl(msr_ops.ctl(i), b->ctl); + + /* Bank is initialized if bits are set in hardware. */ + b->init = !!b->ctl; } } @@ -2098,6 +2101,9 @@ static ssize_t show_bank(struct device *s, struct device_attribute *attr, b = &per_cpu(mce_banks_percpu, s->id)[bank]; + if (!b->init) + return -ENODEV; + return sprintf(buf, "%llx\n", b->ctl); } @@ -2116,6 +2122,9 @@ static ssize_t set_bank(struct device *s, struct device_attribute *attr, b = &per_cpu(mce_banks_percpu, s->id)[bank]; + if (!b->init) + return -ENODEV; + b->ctl = new; mce_restart(); -- 2.17.1
next prev reply other threads:[~2019-04-30 20:32 UTC|newest] Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-04-30 20:32 [PATCH v3 0/6] Handle MCA banks in a per_cpu way Ghannam, Yazen 2019-04-30 20:32 ` [v3,1/6] x86/MCE: Make struct mce_banks[] static Yazen Ghannam 2019-04-30 20:32 ` [PATCH v3 1/6] " Ghannam, Yazen 2019-04-30 20:32 ` [v3,2/6] x86/MCE: Handle MCA controls in a per_cpu way Yazen Ghannam 2019-04-30 20:32 ` [PATCH v3 2/6] " Ghannam, Yazen 2019-04-30 20:32 ` [v3,3/6] x86/MCE/AMD: Don't cache block addresses on SMCA systems Yazen Ghannam 2019-04-30 20:32 ` [PATCH v3 3/6] " Ghannam, Yazen 2019-04-30 20:32 ` [v3,5/6] x86/MCE: Save MCA control bits that get set in hardware Yazen Ghannam 2019-04-30 20:32 ` [PATCH v3 5/6] " Ghannam, Yazen 2019-05-16 15:52 ` Luck, Tony 2019-05-16 16:14 ` Ghannam, Yazen 2019-05-16 16:56 ` Borislav Petkov 2019-05-16 17:09 ` Ghannam, Yazen 2019-05-16 17:21 ` Borislav Petkov 2019-05-16 20:20 ` Ghannam, Yazen 2019-05-16 20:34 ` Borislav Petkov 2019-05-16 20:59 ` Luck, Tony 2019-05-17 10:10 ` Borislav Petkov 2019-05-17 15:46 ` Ghannam, Yazen 2019-05-17 16:37 ` Borislav Petkov 2019-05-17 17:26 ` Luck, Tony 2019-05-17 17:48 ` Borislav Petkov 2019-05-17 18:06 ` Luck, Tony 2019-05-17 19:34 ` Borislav Petkov 2019-05-17 19:44 ` Luck, Tony 2019-05-17 19:50 ` Borislav Petkov 2019-05-17 19:49 ` Ghannam, Yazen 2019-05-17 20:02 ` Borislav Petkov 2019-05-23 20:00 ` Ghannam, Yazen 2019-05-27 23:28 ` Borislav Petkov 2019-06-07 14:49 ` Ghannam, Yazen 2019-06-07 16:37 ` Borislav Petkov 2019-06-07 16:44 ` Ghannam, Yazen 2019-06-07 16:59 ` Borislav Petkov 2019-06-07 17:08 ` Ghannam, Yazen 2019-06-07 17:20 ` Borislav Petkov 2019-06-11 5:13 ` Borislav Petkov 2019-04-30 20:32 ` [v3,4/6] x86/MCE: Make number of MCA banks per_cpu Yazen Ghannam 2019-04-30 20:32 ` [PATCH v3 4/6] " Ghannam, Yazen 2019-05-18 11:25 ` Borislav Petkov 2019-05-21 17:52 ` Ghannam, Yazen 2019-05-21 20:29 ` Borislav Petkov 2019-05-21 20:42 ` Luck, Tony 2019-05-21 23:09 ` Borislav Petkov 2019-05-22 14:01 ` Ghannam, Yazen 2019-04-30 20:32 ` Yazen Ghannam [this message] 2019-04-30 20:32 ` [PATCH v3 6/6] x86/MCE: Treat MCE bank as initialized if control bits set in hardware Ghannam, Yazen
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