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Commit 8f0b8056 authored by Mahesh Salgaonkar's avatar Mahesh Salgaonkar Committed by Michael Ellerman
Browse files

powerpc/pseries: Display machine check error details. 



Extract the MCE error details from RTAS extended log and display it to
console.

With this patch you should now see mce logs like below:

[  142.371818] Severe Machine check interrupt [Recovered]
[  142.371822]   NIP [d00000000ca301b8]: init_module+0x1b8/0x338 [bork_kernel]
[  142.371822]   Initiator: CPU
[  142.371823]   Error type: SLB [Multihit]
[  142.371824]     Effective address: d00000000ca70000

Signed-off-by: default avatarMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent a43c1590

arch/powerpc/include/asm/rtas.h

+5 −0
Original line number Diff line number Diff line
@@ -197,6 +197,11 @@ static inline uint8_t rtas_error_extended(const struct rtas_error_log *elog) 
	return (elog->byte1 & 0x04) >> 2;

}



static inline uint8_t rtas_error_initiator(const struct rtas_error_log *elog)

{

	return (elog->byte2 & 0xf0) >> 4;

}



#define rtas_error_type(x)	((x)->byte3)



static inline

arch/powerpc/platforms/pseries/ras.c

+133 −0
Original line number Diff line number Diff line
@@ -523,6 +523,136 @@ int pSeries_system_reset_exception(struct pt_regs *regs) 
	return 0; /* need to perform reset */

}



#define VAL_TO_STRING(ar, val)	\

	(((val) < ARRAY_SIZE(ar)) ? ar[(val)] : "Unknown")



static void pseries_print_mce_info(struct pt_regs *regs,

				   struct rtas_error_log *errp)

{

	const char *level, *sevstr;

	struct pseries_errorlog *pseries_log;

	struct pseries_mc_errorlog *mce_log;

	u8 error_type, err_sub_type;

	u64 addr;

	u8 initiator = rtas_error_initiator(errp);

	int disposition = rtas_error_disposition(errp);



	static const char * const initiators[] = {

		"Unknown",

		"CPU",

		"PCI",

		"ISA",

		"Memory",

		"Power Mgmt",

	};

	static const char * const mc_err_types[] = {

		"UE",

		"SLB",

		"ERAT",

		"TLB",

		"D-Cache",

		"Unknown",

		"I-Cache",

	};

	static const char * const mc_ue_types[] = {

		"Indeterminate",

		"Instruction fetch",

		"Page table walk ifetch",

		"Load/Store",

		"Page table walk Load/Store",

	};



	/* SLB sub errors valid values are 0x0, 0x1, 0x2 */

	static const char * const mc_slb_types[] = {

		"Parity",

		"Multihit",

		"Indeterminate",

	};



	/* TLB and ERAT sub errors valid values are 0x1, 0x2, 0x3 */

	static const char * const mc_soft_types[] = {

		"Unknown",

		"Parity",

		"Multihit",

		"Indeterminate",

	};



	if (!rtas_error_extended(errp)) {

		pr_err("Machine check interrupt: Missing extended error log\n");

		return;

	}



	pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);

	if (pseries_log == NULL)

		return;



	mce_log = (struct pseries_mc_errorlog *)pseries_log->data;



	error_type = mce_log->error_type;

	err_sub_type = rtas_mc_error_sub_type(mce_log);



	switch (rtas_error_severity(errp)) {

	case RTAS_SEVERITY_NO_ERROR:

		level = KERN_INFO;

		sevstr = "Harmless";

		break;

	case RTAS_SEVERITY_WARNING:

		level = KERN_WARNING;

		sevstr = "";

		break;

	case RTAS_SEVERITY_ERROR:

	case RTAS_SEVERITY_ERROR_SYNC:

		level = KERN_ERR;

		sevstr = "Severe";

		break;

	case RTAS_SEVERITY_FATAL:

	default:

		level = KERN_ERR;

		sevstr = "Fatal";

		break;

	}



	printk("%s%s Machine check interrupt [%s]\n", level, sevstr,

	       disposition == RTAS_DISP_FULLY_RECOVERED ?

	       "Recovered" : "Not recovered");

	if (user_mode(regs)) {

		printk("%s  NIP: [%016lx] PID: %d Comm: %s\n", level,

		       regs->nip, current->pid, current->comm);

	} else {

		printk("%s  NIP [%016lx]: %pS\n", level, regs->nip,

		       (void *)regs->nip);

	}

	printk("%s  Initiator: %s\n", level,

	       VAL_TO_STRING(initiators, initiator));



	switch (error_type) {

	case MC_ERROR_TYPE_UE:

		printk("%s  Error type: %s [%s]\n", level,

		       VAL_TO_STRING(mc_err_types, error_type),

		       VAL_TO_STRING(mc_ue_types, err_sub_type));

		break;

	case MC_ERROR_TYPE_SLB:

		printk("%s  Error type: %s [%s]\n", level,

		       VAL_TO_STRING(mc_err_types, error_type),

		       VAL_TO_STRING(mc_slb_types, err_sub_type));

		break;

	case MC_ERROR_TYPE_ERAT:

	case MC_ERROR_TYPE_TLB:

		printk("%s  Error type: %s [%s]\n", level,

		       VAL_TO_STRING(mc_err_types, error_type),

		       VAL_TO_STRING(mc_soft_types, err_sub_type));

		break;

	default:

		printk("%s  Error type: %s\n", level,

		       VAL_TO_STRING(mc_err_types, error_type));

		break;

	}



	addr = rtas_mc_get_effective_addr(mce_log);

	if (addr)

		printk("%s    Effective address: %016llx\n", level, addr);

}



static int mce_handle_error(struct rtas_error_log *errp)

{

	struct pseries_errorlog *pseries_log;
@@ -585,8 +715,11 @@ static int recover_mce(struct pt_regs *regs, struct rtas_error_log *err) 
	int recovered = 0;

	int disposition = rtas_error_disposition(err);



	pseries_print_mce_info(regs, err);



	if (!(regs->msr & MSR_RI)) {

		/* If MSR_RI isn't set, we cannot recover */

		pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n");

		recovered = 0;



	} else if (disposition == RTAS_DISP_FULLY_RECOVERED) {