linux-kernel - Re: [PATCH 1/3] x86/RAS: Simplify SMCA bank descriptor struct

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Date:   Fri, 4 Nov 2016 16:23:17 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Yazen Ghannam <yazen.ghannam@....com>
Cc:     LKML <linux-kernel@...r.kernel.org>, X86 ML <x86@...nel.org>
Subject: Re: [PATCH 1/3] x86/RAS: Simplify SMCA bank descriptor struct

On Fri, Nov 04, 2016 at 10:44:47AM -0400, Yazen Ghannam wrote:
> Please add:
> Tested-by: Yazen Ghannam <yazen.ghannam@....com>
> 
> Ditto for the others.

Thanks, here's one more which I've been meaning to do:

---
From: Borislav Petkov <bp@...e.de>
Date: Thu, 3 Nov 2016 21:12:33 +0100
Subject: [PATCH] x86/RAS: Hide SMCA bank names

Add accessor functions and hide the smca_names array. Also, add a
sanity-check to bank HWID assignment in get_smca_bank_info().

Signed-off-by: Borislav Petkov <bp@...e.de>
---
 arch/x86/include/asm/mce.h           |  8 +-------
 arch/x86/kernel/cpu/mcheck/mce_amd.c | 32 +++++++++++++++++++++++++++++---
 drivers/edac/mce_amd.c               |  2 +-
 3 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 8ffd21596dd7..748b8da8e627 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -356,13 +356,6 @@ enum smca_bank_types {
 	N_SMCA_BANK_TYPES
 };
 
-struct smca_bank_name {
-	const char *name;	/* Short name for sysfs */
-	const char *long_name;	/* Long name for pretty-printing */
-};
-
-extern struct smca_bank_name smca_names[N_SMCA_BANK_TYPES];
-
 #define HWID_MCATYPE(hwid, mcatype) ((hwid << 16) | mcatype)
 
 struct smca_hwid {
@@ -379,6 +372,7 @@ struct smca_bank {
 
 extern struct smca_bank smca_banks[MAX_NR_BANKS];
 
+extern const char *smca_get_long_name(enum smca_bank_types t);
 #endif
 
 #endif /* _ASM_X86_MCE_H */
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index afeb02b87127..e68a305ff666 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -69,7 +69,12 @@ static const char * const smca_umc_block_names[] = {
 	"misc_umc"
 };
 
-struct smca_bank_name smca_names[] = {
+struct smca_bank_name {
+	const char *name;	/* Short name for sysfs */
+	const char *long_name;	/* Long name for pretty-printing */
+};
+
+static struct smca_bank_name smca_names[] = {
 	[SMCA_LS]	= { "load_store",	"Load Store Unit" },
 	[SMCA_IF]	= { "insn_fetch",	"Instruction Fetch Unit" },
 	[SMCA_L2_CACHE]	= { "l2_cache",		"L2 Cache" },
@@ -84,7 +89,23 @@ struct smca_bank_name smca_names[] = {
 	[SMCA_PSP]	= { "psp",		"Platform Security Processor" },
 	[SMCA_SMU]	= { "smu",		"System Management Unit" },
 };
-EXPORT_SYMBOL_GPL(smca_names);
+
+const char *smca_get_name(enum smca_bank_types t)
+{
+	if (t >= N_SMCA_BANK_TYPES)
+		return NULL;
+
+	return smca_names[t].name;
+}
+
+const char *smca_get_long_name(enum smca_bank_types t)
+{
+	if (t >= N_SMCA_BANK_TYPES)
+		return NULL;
+
+	return smca_names[t].long_name;
+}
+EXPORT_SYMBOL_GPL(smca_get_long_name);
 
 static struct smca_hwid smca_hwid_mcatypes[] = {
 	/* { bank_type, hwid_mcatype, xec_bitmap } */
@@ -163,6 +184,11 @@ static void get_smca_bank_info(unsigned int bank)
 	for (i = 0; i < ARRAY_SIZE(smca_hwid_mcatypes); i++) {
 		s_hwid = &smca_hwid_mcatypes[i];
 		if (hwid_mcatype == s_hwid->hwid_mcatype) {
+
+			WARN(smca_banks[bank].hwid,
+			     "Bank %s already initialized!\n",
+			     smca_get_name(s_hwid->bank_type));
+
 			smca_banks[bank].hwid = s_hwid;
 			smca_banks[bank].id = instance_id;
 			break;
@@ -832,7 +858,7 @@ static const char *get_name(unsigned int bank, struct threshold_block *b)
 	}
 
 	snprintf(buf_mcatype, MAX_MCATYPE_NAME_LEN,
-		 "%s_%x", smca_names[bank_type].name,
+		 "%s_%x", smca_get_name(bank_type),
 			  smca_banks[bank].id);
 	return buf_mcatype;
 }
diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
index 3dee58583d25..80762acd8cc8 100644
--- a/drivers/edac/mce_amd.c
+++ b/drivers/edac/mce_amd.c
@@ -867,7 +867,7 @@ static void decode_smca_errors(struct mce *m)
 		return;
 
 	bank_type = hwid->bank_type;
-	ip_name = smca_names[bank_type].long_name;
+	ip_name = smca_get_long_name(bank_type);
 
 	pr_emerg(HW_ERR "%s Extended Error Code: %d\n", ip_name, xec);
 
-- 
2.10.0

-- 
Regards/Gruss,
    Boris.

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