From: Borislav Petkov <bp@alien8.de>
To: Yazen Ghannam <yazen.ghannam@amd.com>
Cc: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>,
linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org,
x86@kernel.org, Tony Luck <tony.luck@intel.com>,
hpa@zytor.com, Dave Hansen <dave.hansen@linux.intel.com>
Subject: Re: [PATCH v5 2/2] x86/mce: Add support for Extended Physical Address MCA changes
Date: Wed, 13 Apr 2022 16:54:00 +0200 [thread overview]
Message-ID: <YlbkCK9LU2KdXZUG@zn.tnic> (raw)
In-Reply-To: <YlbZ1k1cT1FVJj4W@yaz-ubuntu>
On Wed, Apr 13, 2022 at 02:10:30PM +0000, Yazen Ghannam wrote:
> This function gets called from __mcheck_cpu_init_early() so that the info is
> available before the MCA banks are polled in __mcheck_cpu_init_generic().
Would that work?
I've moved first bank polling into __mcheck_cpu_init_clear_banks()
because, well, this function is clearing the banks so it might as well
poll them first. First bank polling in a init_generic function doesn't
make too much sense anyway.
And __mcheck_cpu_check_banks() functionality is moved into
__mcheck_cpu_init_clear_banks() because, well, silly.
On a quick scan, I don't see problems with such move but the devil is in
the detail.
Hmm?
---
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 99e3ff9607a3..345e068215c4 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1732,21 +1732,8 @@ static void __mcheck_cpu_cap_init(void)
static void __mcheck_cpu_init_generic(void)
{
- enum mcp_flags m_fl = 0;
- mce_banks_t all_banks;
u64 cap;
- if (!mca_cfg.bootlog)
- m_fl = MCP_DONTLOG;
-
- /*
- * Log the machine checks left over from the previous reset. Log them
- * only, do not start processing them. That will happen in mcheck_late_init()
- * when all consumers have been registered on the notifier chain.
- */
- bitmap_fill(all_banks, MAX_NR_BANKS);
- machine_check_poll(MCP_UC | MCP_QUEUE_LOG | m_fl, &all_banks);
-
cr4_set_bits(X86_CR4_MCE);
rdmsrl(MSR_IA32_MCG_CAP, cap);
@@ -1757,33 +1744,21 @@ static void __mcheck_cpu_init_generic(void)
static void __mcheck_cpu_init_clear_banks(void)
{
struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array);
+ enum mcp_flags m_fl = 0;
+ mce_banks_t all_banks;
+ u64 msrval;
int i;
- for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
- struct mce_bank *b = &mce_banks[i];
-
- if (!b->init)
- continue;
- wrmsrl(mca_msr_reg(i, MCA_CTL), b->ctl);
- wrmsrl(mca_msr_reg(i, MCA_STATUS), 0);
- }
-}
+ if (!mca_cfg.bootlog)
+ m_fl = MCP_DONTLOG;
-/*
- * Do a final check to see if there are any unused/RAZ banks.
- *
- * This must be done after the banks have been initialized and any quirks have
- * been applied.
- *
- * Do not call this from any user-initiated flows, e.g. CPU hotplug or sysfs.
- * Otherwise, a user who disables a bank will not be able to re-enable it
- * without a system reboot.
- */
-static void __mcheck_cpu_check_banks(void)
-{
- struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array);
- u64 msrval;
- int i;
+ /*
+ * Log the machine checks left over from the previous reset. Log them
+ * only, do not start processing them. That will happen in mcheck_late_init()
+ * when all consumers have been registered on the notifier chain.
+ */
+ bitmap_fill(all_banks, MAX_NR_BANKS);
+ machine_check_poll(MCP_UC | MCP_QUEUE_LOG | m_fl, &all_banks);
for (i = 0; i < this_cpu_read(mce_num_banks); i++) {
struct mce_bank *b = &mce_banks[i];
@@ -1791,6 +1766,9 @@ static void __mcheck_cpu_check_banks(void)
if (!b->init)
continue;
+ wrmsrl(mca_msr_reg(i, MCA_CTL), b->ctl);
+ wrmsrl(mca_msr_reg(i, MCA_STATUS), 0);
+
rdmsrl(mca_msr_reg(i, MCA_CTL), msrval);
b->init = !!msrval;
}
@@ -2159,7 +2137,6 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c)
__mcheck_cpu_init_generic();
__mcheck_cpu_init_vendor(c);
__mcheck_cpu_init_clear_banks();
- __mcheck_cpu_check_banks();
__mcheck_cpu_setup_timer();
}
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2022-04-13 14:54 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-12 15:40 [PATCH v5 0/2] x86/mce: Support extended MCA_ADDR address on SMCA systems Smita Koralahalli
2022-04-12 15:40 ` [PATCH v5 1/2] x86/mce: Define function to extract ErrorAddr from MCA_ADDR Smita Koralahalli
2022-04-12 15:40 ` [PATCH v5 2/2] x86/mce: Add support for Extended Physical Address MCA changes Smita Koralahalli
2022-04-13 10:21 ` Borislav Petkov
2022-04-13 14:10 ` Yazen Ghannam
2022-04-13 14:54 ` Borislav Petkov [this message]
2022-04-13 15:59 ` Luck, Tony
2022-04-13 16:19 ` Borislav Petkov
2022-04-13 19:40 ` Yazen Ghannam
2022-04-14 9:11 ` Borislav Petkov
2022-04-15 14:56 ` Yazen Ghannam
2022-04-15 16:37 ` Luck, Tony
2022-06-09 19:19 ` Yazen Ghannam
2022-06-27 15:56 ` Borislav Petkov
2022-07-12 13:51 ` Yazen Ghannam
2022-07-12 14:08 ` Borislav Petkov
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