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* [2/3] x86/MCE/AMD, EDAC/mce_amd: Enumerate Reserved SMCA bank type
@ 2018-02-01 18:48 Yazen Ghannam
  0 siblings, 0 replies; 3+ messages in thread
From: Yazen Ghannam @ 2018-02-01 18:48 UTC (permalink / raw)
  To: linux-edac; +Cc: Yazen Ghannam, linux-kernel, bp, tony.luck, x86

From: Yazen Ghannam <yazen.ghannam@amd.com>

Currently, bank 4 is reserved on Fam17h, so we chose not to initialize
bank 4 in the smca_banks array. This means that when we check if a bank
is initialized, like during boot or resume, we will see that bank 4 is
not initialized and try to initialize it. This may cause a call trace,
when resuming from suspend, due to *on_cpu() calls in the init path.

Reserved banks will be read-as-zero, so their MCA_IPID register will be
zero. So, like the smca_banks array, the threshold_banks array will not
have an entry for a reserved bank since all its MCA_MISC* registers will
be zero.

Enumerate a "Reserved" bank type that matches on a HWID_MCATYPE of 0,0.

Use the "Reserved" type when checking if a bank is reserved. It's
possible that other bank numbers may be reserved on future systems.

Don't try to find the block address on reserved banks.

Cc: <stable@vger.kernel.org> # 4.14.x
Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
---
 arch/x86/include/asm/mce.h           |  1 +
 arch/x86/kernel/cpu/mcheck/mce_amd.c |  7 +++++++
 drivers/edac/mce_amd.c               | 11 +++++++----
 3 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 96ea4b5ba658..340070415c2c 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -346,6 +346,7 @@ enum smca_bank_types {
 	SMCA_IF,	/* Instruction Fetch */
 	SMCA_L2_CACHE,	/* L2 Cache */
 	SMCA_DE,	/* Decoder Unit */
+	SMCA_RESERVED,	/* Reserved */
 	SMCA_EX,	/* Execution Unit */
 	SMCA_FP,	/* Floating Point */
 	SMCA_L3_CACHE,	/* L3 Cache */
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index 4e16afc0794d..bf53b4549a17 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -82,6 +82,7 @@ static struct smca_bank_name smca_names[] = {
 	[SMCA_IF]	= { "insn_fetch",	"Instruction Fetch Unit" },
 	[SMCA_L2_CACHE]	= { "l2_cache",		"L2 Cache" },
 	[SMCA_DE]	= { "decode_unit",	"Decode Unit" },
+	[SMCA_RESERVED]	= { "reserved",		"Reserved" },
 	[SMCA_EX]	= { "execution_unit",	"Execution Unit" },
 	[SMCA_FP]	= { "floating_point",	"Floating Point Unit" },
 	[SMCA_L3_CACHE]	= { "l3_cache",		"L3 Cache" },
@@ -127,6 +128,9 @@ static enum smca_bank_types smca_get_bank_type(unsigned int bank)
 static struct smca_hwid smca_hwid_mcatypes[] = {
 	/* { bank_type, hwid_mcatype, xec_bitmap } */
 
+	/* Reserved type */
+	{ SMCA_RESERVED, HWID_MCATYPE(0x00, 0x0), 0x0 },
+
 	/* ZN Core (HWID=0xB0) MCA types */
 	{ SMCA_LS,	 HWID_MCATYPE(0xB0, 0x0), 0x1FFFEF },
 	{ SMCA_IF,	 HWID_MCATYPE(0xB0, 0x1), 0x3FFF },
@@ -433,6 +437,9 @@ static u32 get_block_address(unsigned int cpu, u32 current_addr, u32 low, u32 hi
 	u32 addr = 0, offset = 0;
 
 	if (mce_flags.smca) {
+		if (smca_get_bank_type(bank) == SMCA_RESERVED)
+			return addr;
+
 		if (!block) {
 			addr = MSR_AMD64_SMCA_MCx_MISC(bank);
 		} else {
diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
index a11a671c7a38..2ab4d61ee47e 100644
--- a/drivers/edac/mce_amd.c
+++ b/drivers/edac/mce_amd.c
@@ -854,21 +854,24 @@ static void decode_mc6_mce(struct mce *m)
 static void decode_smca_error(struct mce *m)
 {
 	struct smca_hwid *hwid;
-	unsigned int bank_type;
+	enum smca_bank_types bank_type;
 	const char *ip_name;
 	u8 xec = XEC(m->status, xec_mask);
 
 	if (m->bank >= ARRAY_SIZE(smca_banks))
 		return;
 
-	if (x86_family(m->cpuid) >= 0x17 && m->bank == 4)
-		pr_emerg(HW_ERR "Bank 4 is reserved on Fam17h.\n");
-
 	hwid = smca_banks[m->bank].hwid;
 	if (!hwid)
 		return;
 
 	bank_type = hwid->bank_type;
+
+	if (bank_type == SMCA_RESERVED) {
+		pr_emerg(HW_ERR "Bank %d is reserved.\n", m->bank);
+		return;
+	}
+
 	ip_name = smca_get_long_name(bank_type);
 
 	pr_emerg(HW_ERR "%s Extended Error Code: %d\n", ip_name, xec);

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* [2/3] x86/MCE/AMD, EDAC/mce_amd: Enumerate Reserved SMCA bank type
@ 2018-02-08 15:15 Borislav Petkov
  0 siblings, 0 replies; 3+ messages in thread
From: Borislav Petkov @ 2018-02-08 15:15 UTC (permalink / raw)
  To: Yazen Ghannam; +Cc: linux-edac, linux-kernel, bp, tony.luck, x86

On Thu, Feb 01, 2018 at 12:48:12PM -0600, Yazen Ghannam wrote:
> From: Yazen Ghannam <yazen.ghannam@amd.com>
> 
> Currently, bank 4 is reserved on Fam17h, so we chose not to initialize
> bank 4 in the smca_banks array. This means that when we check if a bank
> is initialized, like during boot or resume, we will see that bank 4 is
> not initialized and try to initialize it. This may cause a call trace,
> when resuming from suspend, due to *on_cpu() calls in the init path.

Please be more specific: the rdmsr_*_on_cpu() calls issue an IPI but we're
running with interrupts disabled, which triggers:

 WARNING: CPU: 0 PID: 11523 at kernel/smp.c:291 smp_call_function_single+0xdc/0xe0

> Reserved banks will be read-as-zero, so their MCA_IPID register will be
> zero. So, like the smca_banks array, the threshold_banks array will not
> have an entry for a reserved bank since all its MCA_MISC* registers will
> be zero.
> 
> Enumerate a "Reserved" bank type that matches on a HWID_MCATYPE of 0,0.
> 
> Use the "Reserved" type when checking if a bank is reserved. It's
> possible that other bank numbers may be reserved on future systems.
> 
> Don't try to find the block address on reserved banks.
> 
> Cc: <stable@vger.kernel.org> # 4.14.x
> Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>
> ---
>  arch/x86/include/asm/mce.h           |  1 +
>  arch/x86/kernel/cpu/mcheck/mce_amd.c |  7 +++++++
>  drivers/edac/mce_amd.c               | 11 +++++++----
>  3 files changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
> index 96ea4b5ba658..340070415c2c 100644
> --- a/arch/x86/include/asm/mce.h
> +++ b/arch/x86/include/asm/mce.h
> @@ -346,6 +346,7 @@ enum smca_bank_types {
>  	SMCA_IF,	/* Instruction Fetch */
>  	SMCA_L2_CACHE,	/* L2 Cache */
>  	SMCA_DE,	/* Decoder Unit */
> +	SMCA_RESERVED,	/* Reserved */
>  	SMCA_EX,	/* Execution Unit */
>  	SMCA_FP,	/* Floating Point */
>  	SMCA_L3_CACHE,	/* L3 Cache */
> diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
> index 4e16afc0794d..bf53b4549a17 100644
> --- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
> +++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
> @@ -82,6 +82,7 @@ static struct smca_bank_name smca_names[] = {
>  	[SMCA_IF]	= { "insn_fetch",	"Instruction Fetch Unit" },
>  	[SMCA_L2_CACHE]	= { "l2_cache",		"L2 Cache" },
>  	[SMCA_DE]	= { "decode_unit",	"Decode Unit" },
> +	[SMCA_RESERVED]	= { "reserved",		"Reserved" },
>  	[SMCA_EX]	= { "execution_unit",	"Execution Unit" },
>  	[SMCA_FP]	= { "floating_point",	"Floating Point Unit" },
>  	[SMCA_L3_CACHE]	= { "l3_cache",		"L3 Cache" },
> @@ -127,6 +128,9 @@ static enum smca_bank_types smca_get_bank_type(unsigned int bank)
>  static struct smca_hwid smca_hwid_mcatypes[] = {
>  	/* { bank_type, hwid_mcatype, xec_bitmap } */
>  
> +	/* Reserved type */
> +	{ SMCA_RESERVED, HWID_MCATYPE(0x00, 0x0), 0x0 },
> +
>  	/* ZN Core (HWID=0xB0) MCA types */
>  	{ SMCA_LS,	 HWID_MCATYPE(0xB0, 0x0), 0x1FFFEF },
>  	{ SMCA_IF,	 HWID_MCATYPE(0xB0, 0x1), 0x3FFF },
> @@ -433,6 +437,9 @@ static u32 get_block_address(unsigned int cpu, u32 current_addr, u32 low, u32 hi
>  	u32 addr = 0, offset = 0;
>  
>  	if (mce_flags.smca) {

As a last patch in the series: please carve the code in this
if-statement into a smca_get_block_address() helper. And it doesn't need
the stable tag as it is only a cleanup.

Thx.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* [2/3] x86/MCE/AMD, EDAC/mce_amd: Enumerate Reserved SMCA bank type
@ 2018-02-14 16:28 Yazen Ghannam
  0 siblings, 0 replies; 3+ messages in thread
From: Yazen Ghannam @ 2018-02-14 16:28 UTC (permalink / raw)
  To: Borislav Petkov
  Cc: linux-edac@vger.kernel.org, linux-kernel@vger.kernel.org,
	bp@suse.de, tony.luck@intel.com, x86@kernel.org

> -----Original Message-----
> From: linux-edac-owner@vger.kernel.org [mailto:linux-edac-
> owner@vger.kernel.org] On Behalf Of Borislav Petkov
> Sent: Thursday, February 8, 2018 10:15 AM
> To: Ghannam, Yazen <Yazen.Ghannam@amd.com>
> Cc: linux-edac@vger.kernel.org; linux-kernel@vger.kernel.org; bp@suse.de;
> tony.luck@intel.com; x86@kernel.org
> Subject: Re: [PATCH 2/3] x86/MCE/AMD, EDAC/mce_amd: Enumerate Reserved
> SMCA bank type
> 
> On Thu, Feb 01, 2018 at 12:48:12PM -0600, Yazen Ghannam wrote:
> > From: Yazen Ghannam <yazen.ghannam@amd.com>
> >
> > Currently, bank 4 is reserved on Fam17h, so we chose not to initialize
> > bank 4 in the smca_banks array. This means that when we check if a bank
> > is initialized, like during boot or resume, we will see that bank 4 is
> > not initialized and try to initialize it. This may cause a call trace,
> > when resuming from suspend, due to *on_cpu() calls in the init path.
> 
> Please be more specific: the rdmsr_*_on_cpu() calls issue an IPI but we're
> running with interrupts disabled, which triggers:
> 
>  WARNING: CPU: 0 PID: 11523 at kernel/smp.c:291
> smp_call_function_single+0xdc/0xe0
> 

Okay.

...
> > @@ -433,6 +437,9 @@ static u32 get_block_address(unsigned int cpu, u32
> current_addr, u32 low, u32 hi
> >  	u32 addr = 0, offset = 0;
> >
> >  	if (mce_flags.smca) {
> 
> As a last patch in the series: please carve the code in this
> if-statement into a smca_get_block_address() helper. And it doesn't need
> the stable tag as it is only a cleanup.
> 

Will do.

Thanks,
Yazen

^ permalink raw reply	[flat|nested] 3+ messages in thread

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