On Wed, Mar 22, 2017 at 02:29:30PM -0500, Yazen Ghannam wrote:
> From: Yazen Ghannam <yazen.ghan...@amd.com>
>
> We have support for the new SMCA MCA_DE{STAT,ADDR} registers in Linux. So
> we've used these registers in place of MCA_{STATUS,ADDR} on SMCA systems.
> However, the guidance for current implementations of SMCA is to continue
> using MCA_{STATUS,ADDR} and to use MCA_DE{STAT,ADDR} only if a Deferred
> error was not found in the former registers. This also means we shouldn't
> clear MCA_CONFIG[LogDeferredInMcaStat].
>
> Redo the AMD Deferred error interrupt handler to follow the guidance for
> current SMCA systems. Also, don't break after finding the first error.
>
> Don't clear MCA_CONFIG[LogDeferredInMcaStat] during AMD mcheck init.
>
> Signed-off-by: Yazen Ghannam <yazen.ghan...@amd.com>
> ---
> arch/x86/kernel/cpu/mcheck/mce_amd.c | 47
> ++++++++++++++++--------------------
> 1 file changed, 21 insertions(+), 26 deletions(-)
>
> diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c
> b/arch/x86/kernel/cpu/mcheck/mce_amd.c
> index 524cc57..4e459e0 100644
> --- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
> +++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
> @@ -472,20 +472,6 @@ prepare_threshold_block(unsigned int bank, unsigned int
> block, u32 addr,
> smca_high |= BIT(0);
>
> /*
> - * SMCA logs Deferred Error information in MCA_DE{STAT,ADDR}
> - * registers with the option of additionally logging to
> - * MCA_{STATUS,ADDR} if MCA_CONFIG[LogDeferredInMcaStat] is set.
> - *
> - * This bit is usually set by BIOS to retain the old behavior
> - * for OSes that don't use the new registers. Linux supports the
> - * new registers so let's disable that additional logging here.
> - *
> - * MCA_CONFIG[LogDeferredInMcaStat] is bit 34 (bit 2 in the high
> - * portion of the MSR).
> - */
> - smca_high &= ~BIT(2);
> -
> - /*
> * SMCA sets the Deferred Error Interrupt type per bank.
> *
> * MCA_CONFIG[DeferredIntTypeSupported] is bit 5, and tells us
> @@ -756,7 +742,8 @@ int umc_normaddr_to_sysaddr(u64 norm_addr, u16 nid, u8
> umc, u64 *sys_addr)
> EXPORT_SYMBOL_GPL(umc_normaddr_to_sysaddr);
>
> static void
> -__log_error(unsigned int bank, bool deferred_err, bool threshold_err, u64
> misc)
> +__log_error(unsigned int bank, bool deferred_err, bool use_smca_destat,
> + bool threshold_err, u64 misc)
So I had to paste the function signature in a separate vim window and
keep looking between those arguments' names and the function calls.
Because if I look at:
__log_error(bank, true, false, false, 0);
I absolutely have no clue what that code does. So we need to think of
something better. From the looks of it, I guess we dealt with a single
__log_error() function long enough. Perhaps it is time for separation:
log_error_deferred
log_error_smca
log_error...
and have a function __log_error() which all three call to do the work
which all three share.
That should make the code readable again IMO. __log_error() as it is now
is hard to follow anyway.
> {
> u32 msr_status = msr_ops.status(bank);
> u32 msr_addr = msr_ops.addr(bank);
> @@ -765,7 +752,7 @@ __log_error(unsigned int bank, bool deferred_err, bool
> threshold_err, u64 misc)
>
> WARN_ON_ONCE(deferred_err && threshold_err);
>
> - if (deferred_err && mce_flags.smca) {
> + if (deferred_err && use_smca_destat) {
> msr_status = MSR_AMD64_SMCA_MCx_DESTAT(bank);
> msr_addr = MSR_AMD64_SMCA_MCx_DEADDR(bank);
> }
> @@ -807,6 +794,10 @@ __log_error(unsigned int bank, bool deferred_err, bool
> threshold_err, u64 misc)
>
> mce_log(&m);
>
> + /* We should still clear MCA_DESTAT even if we used MCA_STATUS. */
> + if (mce_flags.smca && !use_smca_destat)
> + wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(bank), 0);
> +
> wrmsrl(msr_status, 0);
> }
>
> @@ -832,25 +823,29 @@ asmlinkage __visible void __irq_entry
> smp_trace_deferred_error_interrupt(void)
> exiting_ack_irq();
> }
>
> +static inline bool check_deferred_status(u64 status)
This function name does not tell me anything.
if (is_deferred_error(status))
tells me more.
Thanks.
--
Regards/Gruss,
Boris.
SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284
(AG Nürnberg)
--
