[PATCH] x86: detect use of extended APIC ID for AMD CPUs

[PATCH] x86: detect use of extended APIC ID for AMD CPUs

[Andreas Herrmann]

Booting a 32-bit kernel on Magny-Cours results in the following panic

  ...
  Using APIC driver default
  ...
  Overriding APIC driver with bigsmp
  ...
  Getting VERSION: 80050010
  Getting VERSION: 80050010
  Getting ID: 10000000
  Getting ID: ef000000
  Getting LVT0: 700
  Getting LVT1: 10000
  Kernel panic - not syncing: Boot APIC ID in local APIC unexpected (16 vs 0)
  Pid: 1, comm: swapper Not tainted 2.6.30-rcX #2
  Call Trace:
   [<c05194da>] ? panic+0x38/0xd3
   [<c0743102>] ? native_smp_prepare_cpus+0x259/0x31f
   [<c073b19d>] ? kernel_init+0x3e/0x141
   [<c073b15f>] ? kernel_init+0x0/0x141
   [<c020325f>] ? kernel_thread_helper+0x7/0x10

The reason is that default_get_apic_id handled extension of local APIC
ID field just in case of XAPIC.
Thus for this AMD CPU, default_get_apic_id() returns 0 and
bigsmp_get_apic_id() returns 16 which leads to the respective kernel
panic.

This patch introduces a Linux specific feature flag to indicate
support for extended APIC id (8 bits instead of 4 bits width) and sets
the flag on AMD CPUs if applicable.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
---
 arch/x86/include/asm/apic.h       |    2 +-
 arch/x86/include/asm/cpufeature.h |    1 +
 arch/x86/kernel/cpu/amd.c         |    9 +++++++++
 3 files changed, 11 insertions(+), 1 deletions(-)

Normally you would run 64-bit kernel on such a CPU which correctly
handles 8-bit APIC id. So this is not a big issue, but it's still a
bug in the 32-bit case.

Patch is against tip/master plus 5 patches from
"[PATCH 0/5 v3] x86: adapt CPU topology detection for AMD Magny-Cours"
Please apply.


Thanks,

Andreas

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 229d0be..bb7d479 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -402,7 +402,7 @@ static inline unsigned default_get_apic_id(unsigned long x)
 {
 	unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
 
-	if (APIC_XAPIC(ver))
+	if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID))
 		return (x >> 24) & 0xFF;
 	else
 		return (x >> 24) & 0x0F;
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 7abe596..6143bfb 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -95,6 +95,7 @@
 #define X86_FEATURE_NONSTOP_TSC	(3*32+24) /* TSC does not stop in C states */
 #define X86_FEATURE_CLFLUSH_MONITOR (3*32+25) /* "" clflush reqd with monitor */
 #define X86_FEATURE_AMD_DCM     (3*32+26) /* multi-node processor */
+#define X86_FEATURE_EXTD_APICID	(3*32+27) /* has extended APICID (8 bits) */
 
 /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
 #define X86_FEATURE_XMM3	(4*32+ 0) /* "pni" SSE-3 */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 8c27925..551adb8 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -409,6 +409,15 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
 		    (c->x86_model == 8 && c->x86_mask >= 8))
 			set_cpu_cap(c, X86_FEATURE_K6_MTRR);
 #endif
+#ifdef CONFIG_X86_LOCAL_APIC
+	/* check CPU config space for extended APIC ID */
+	if (c->x86 >= 0xf) {
+		unsigned int val;
+		val = read_pci_config(0, 24, 0, 0x68);
+		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
+			set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
+	}
+#endif
 }
 
 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
-- 
1.6.0.4

[tip:x86/urgent] x86: Detect use of extended APIC ID for AMD CPUs

[tip-bot for Andreas Herrmann]

Commit-ID:  37f36c1017f0032fa7a1fb85a0cddfc0d526d17f
Gitweb:     http://git.kernel.org/tip/37f36c1017f0032fa7a1fb85a0cddfc0d526d17f
Author:     Andreas Herrmann <andreas.herrmann3@amd.com>
AuthorDate: Thu, 4 Jun 2009 12:40:16 +0200
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Sun, 7 Jun 2009 16:39:38 +0200

x86: Detect use of extended APIC ID for AMD CPUs

Booting a 32-bit kernel on Magny-Cours results in the following panic

  ...
  Using APIC driver default
  ...
  Overriding APIC driver with bigsmp
  ...
  Getting VERSION: 80050010
  Getting VERSION: 80050010
  Getting ID: 10000000
  Getting ID: ef000000
  Getting LVT0: 700
  Getting LVT1: 10000
  Kernel panic - not syncing: Boot APIC ID in local APIC unexpected (16 vs 0)
  Pid: 1, comm: swapper Not tainted 2.6.30-rcX #2
  Call Trace:
   [<c05194da>] ? panic+0x38/0xd3
   [<c0743102>] ? native_smp_prepare_cpus+0x259/0x31f
   [<c073b19d>] ? kernel_init+0x3e/0x141
   [<c073b15f>] ? kernel_init+0x0/0x141
   [<c020325f>] ? kernel_thread_helper+0x7/0x10

The reason is that default_get_apic_id handled extension of local APIC
ID field just in case of XAPIC.

Thus for this AMD CPU, default_get_apic_id() returns 0 and
bigsmp_get_apic_id() returns 16 which leads to the respective kernel
panic.

This patch introduces a Linux specific feature flag to indicate
support for extended APIC id (8 bits instead of 4 bits width) and sets
the flag on AMD CPUs if applicable.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: <stable@kernel.org>
LKML-Reference: <20090604104016.GT5736@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
 arch/x86/include/asm/apic.h       |    2 +-
 arch/x86/include/asm/cpufeature.h |    1 +
 arch/x86/kernel/cpu/amd.c         |   10 ++++++++++
 3 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 42f2f83..9b2c049 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -410,7 +410,7 @@ static inline unsigned default_get_apic_id(unsigned long x)
 {
 	unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
 
-	if (APIC_XAPIC(ver))
+	if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID))
 		return (x >> 24) & 0xFF;
 	else
 		return (x >> 24) & 0x0F;
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index bb83b1c..78dee4f 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -94,6 +94,7 @@
 #define X86_FEATURE_TSC_RELIABLE (3*32+23) /* TSC is known to be reliable */
 #define X86_FEATURE_NONSTOP_TSC	(3*32+24) /* TSC does not stop in C states */
 #define X86_FEATURE_CLFLUSH_MONITOR (3*32+25) /* "" clflush reqd with monitor */
+#define X86_FEATURE_EXTD_APICID	(3*32+26) /* has extended APICID (8 bits) */
 
 /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
 #define X86_FEATURE_XMM3	(4*32+ 0) /* "pni" SSE-3 */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 7e4a459..fae8be8 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -351,6 +351,16 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
 		    (c->x86_model == 8 && c->x86_mask >= 8))
 			set_cpu_cap(c, X86_FEATURE_K6_MTRR);
 #endif
+#ifdef CONFIG_X86_LOCAL_APIC
+	/* check CPU config space for extended APIC ID */
+	if (c->x86 >= 0xf) {
+		unsigned int val;
+
+		val = read_pci_config(0, 24, 0, 0x68);
+		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
+			set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
+	}
+#endif
 }
 
 static void __cpuinit init_amd(struct cpuinfo_x86 *c)

Re: [tip:x86/urgent] x86: Detect use of extended APIC ID for AMD CPUs

[Ingo Molnar]

* tip-bot for Andreas Herrmann <andreas.herrmann3@amd.com> wrote:

> +#ifdef CONFIG_X86_LOCAL_APIC
> +	/* check CPU config space for extended APIC ID */
> +	if (c->x86 >= 0xf) {
> +		unsigned int val;
> +
> +		val = read_pci_config(0, 24, 0, 0x68);
> +		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
> +			set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
> +	}
> +#endif

It's possible to enable local APIC but not CONFIG_PCI - in that case 
this sequence will fail to build.

	Ingo

Re: [tip:x86/urgent] x86: Detect use of extended APIC ID for AMD CPUs

[Yinghai Lu]

tip-bot for Andreas Herrmann wrote:
> Commit-ID:  37f36c1017f0032fa7a1fb85a0cddfc0d526d17f
> Gitweb:     http://git.kernel.org/tip/37f36c1017f0032fa7a1fb85a0cddfc0d526d17f
> Author:     Andreas Herrmann <andreas.herrmann3@amd.com>
> AuthorDate: Thu, 4 Jun 2009 12:40:16 +0200
> Committer:  Ingo Molnar <mingo@elte.hu>
> CommitDate: Sun, 7 Jun 2009 16:39:38 +0200
> 
> x86: Detect use of extended APIC ID for AMD CPUs
> 
> Booting a 32-bit kernel on Magny-Cours results in the following panic
> 
>   ...
>   Using APIC driver default
>   ...
>   Overriding APIC driver with bigsmp
>   ...
>   Getting VERSION: 80050010
>   Getting VERSION: 80050010
>   Getting ID: 10000000
>   Getting ID: ef000000
>   Getting LVT0: 700
>   Getting LVT1: 10000
>   Kernel panic - not syncing: Boot APIC ID in local APIC unexpected (16 vs 0)
>   Pid: 1, comm: swapper Not tainted 2.6.30-rcX #2
>   Call Trace:
>    [<c05194da>] ? panic+0x38/0xd3
>    [<c0743102>] ? native_smp_prepare_cpus+0x259/0x31f
>    [<c073b19d>] ? kernel_init+0x3e/0x141
>    [<c073b15f>] ? kernel_init+0x0/0x141
>    [<c020325f>] ? kernel_thread_helper+0x7/0x10
> 
> The reason is that default_get_apic_id handled extension of local APIC
> ID field just in case of XAPIC.
> 
> Thus for this AMD CPU, default_get_apic_id() returns 0 and
> bigsmp_get_apic_id() returns 16 which leads to the respective kernel
> panic.
> 
> This patch introduces a Linux specific feature flag to indicate
> support for extended APIC id (8 bits instead of 4 bits width) and sets
> the flag on AMD CPUs if applicable.
> 
> Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
> Cc: <stable@kernel.org>
> LKML-Reference: <20090604104016.GT5736@alberich.amd.com>
> Signed-off-by: Ingo Molnar <mingo@elte.hu>
> 
> 
> ---
>  arch/x86/include/asm/apic.h       |    2 +-
>  arch/x86/include/asm/cpufeature.h |    1 +
>  arch/x86/kernel/cpu/amd.c         |   10 ++++++++++
>  3 files changed, 12 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
> index 42f2f83..9b2c049 100644
> --- a/arch/x86/include/asm/apic.h
> +++ b/arch/x86/include/asm/apic.h
> @@ -410,7 +410,7 @@ static inline unsigned default_get_apic_id(unsigned long x)
>  {
>  	unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
>  
> -	if (APIC_XAPIC(ver))
> +	if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID))
>  		return (x >> 24) & 0xFF;
>  	else
>  		return (x >> 24) & 0x0F;

looks like we should fix APIC_XAPIC() or have one global apic_ver.

YH

Re: [tip:x86/urgent] x86: Detect use of extended APIC ID for AMD CPUs

[Andreas Herrmann]

On Sun, Jun 07, 2009 at 05:33:27PM +0200, Ingo Molnar wrote:
> 
> * tip-bot for Andreas Herrmann <andreas.herrmann3@amd.com> wrote:
> 
> > +#ifdef CONFIG_X86_LOCAL_APIC
> > +	/* check CPU config space for extended APIC ID */
> > +	if (c->x86 >= 0xf) {
> > +		unsigned int val;
> > +
> > +		val = read_pci_config(0, 24, 0, 0x68);
> > +		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
> > +			set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
> > +	}
> > +#endif
> 
> It's possible to enable local APIC but not CONFIG_PCI - in that case 
> this sequence will fail to build.

Arrgh, thought that the stuff in early.c is always compiled in. Just
checked arch/x86/pci/Makefile showing
  obj-y                           += common.o early.o
and I didn't check arch/x86/Makefile which contains
  drivers-$(CONFIG_PCI)            += arch/x86/pci/

Sorry.
I'll send an updated patch.


Andreas

Re: [tip:x86/urgent] x86: Detect use of extended APIC ID for AMD CPUs

[Andreas Herrmann]

On Sun, Jun 07, 2009 at 11:46:51AM -0700, Yinghai Lu wrote:
> tip-bot for Andreas Herrmann wrote:
> > diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
> > index 42f2f83..9b2c049 100644
> > --- a/arch/x86/include/asm/apic.h
> > +++ b/arch/x86/include/asm/apic.h
> > @@ -410,7 +410,7 @@ static inline unsigned default_get_apic_id(unsigned long x)
> >  {
> >  	unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
> >  
> > -	if (APIC_XAPIC(ver))
> > +	if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID))
> >  		return (x >> 24) & 0xFF;
> >  	else
> >  		return (x >> 24) & 0x0F;
> 
> looks like we should fix APIC_XAPIC() or have one global apic_ver.

I thought to set the new flag for Intel as well and to replace
APIC_XAPIC with checks for that flag. But for some reason this was
ugly as lapic access must be configured before you can check the
APIC_VERSION and so I decided to keep Intel code as is and not to
potentially introduce regresions.


Regards,
Andreas

[PATCH v2] x86: detect use of extended APIC ID for AMD CPUs

[Andreas Herrmann]

Booting a 32-bit kernel on Magny-Cours results in the following panic

  ...
  Using APIC driver default
  ...
  Overriding APIC driver with bigsmp
  ...
  Getting VERSION: 80050010
  Getting VERSION: 80050010
  Getting ID: 10000000
  Getting ID: ef000000
  Getting LVT0: 700
  Getting LVT1: 10000
  Kernel panic - not syncing: Boot APIC ID in local APIC unexpected (16
vs 0)
  Pid: 1, comm: swapper Not tainted 2.6.30-rc3-numa-fixup-nonuma #2
  Call Trace:
   [<c05194da>] ? panic+0x38/0xd3
   [<c0743102>] ? native_smp_prepare_cpus+0x259/0x31f
   [<c073b19d>] ? kernel_init+0x3e/0x141
   [<c073b15f>] ? kernel_init+0x0/0x141
   [<c020325f>] ? kernel_thread_helper+0x7/0x10

The reason is that default_get_apic_id handled extension of local APIC
ID field just in case of XAPIC.
Thus for this AMD CPU, default_get_apic_id() returns 0 and
bigsmp_get_apic_id() returns 16 which leads to the respective kernel
panic.

This patch introduces a Linux specific feature flag to indicate
support for extended APIC id (8 bits instead of 4 bits width) and sets
the flag on AMD CPUs if applicable.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
---
 arch/x86/include/asm/apic.h       |    2 +-
 arch/x86/include/asm/cpufeature.h |    1 +
 arch/x86/kernel/cpu/amd.c         |   10 ++++++++++
 3 files changed, 12 insertions(+), 1 deletions(-)

New patch version
- is against tip/x86/urgent (as you have tried to integrate the previous
  patch version into this branch)
- avoids linker error in case of CONFIG_PCI=n

Regards,
Andreas

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 42f2f83..9b2c049 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -410,7 +410,7 @@ static inline unsigned default_get_apic_id(unsigned long x)
 {
 	unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
 
-	if (APIC_XAPIC(ver))
+	if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID))
 		return (x >> 24) & 0xFF;
 	else
 		return (x >> 24) & 0x0F;
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index bb83b1c..78dee4f 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -94,6 +94,7 @@
 #define X86_FEATURE_TSC_RELIABLE (3*32+23) /* TSC is known to be reliable */
 #define X86_FEATURE_NONSTOP_TSC	(3*32+24) /* TSC does not stop in C states */
 #define X86_FEATURE_CLFLUSH_MONITOR (3*32+25) /* "" clflush reqd with monitor */
+#define X86_FEATURE_EXTD_APICID	(3*32+26) /* has extended APICID (8 bits) */
 
 /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
 #define X86_FEATURE_XMM3	(4*32+ 0) /* "pni" SSE-3 */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 7e4a459..841ed9f 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -6,6 +6,7 @@
 #include <asm/processor.h>
 #include <asm/apic.h>
 #include <asm/cpu.h>
+#include <asm/pci-direct.h>
 
 #ifdef CONFIG_X86_64
 # include <asm/numa_64.h>
@@ -351,6 +352,15 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
 		    (c->x86_model == 8 && c->x86_mask >= 8))
 			set_cpu_cap(c, X86_FEATURE_K6_MTRR);
 #endif
+#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
+	/* check CPU config space for extended APIC ID */
+	if (c->x86 >= 0xf) {
+		unsigned int val;
+		val = read_pci_config(0, 24, 0, 0x68);
+		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
+			set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
+	}
+#endif
 }
 
 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
-- 
1.6.3.1

[PATCH v3] x86: detect use of extended APIC ID for AMD CPUs

[Andreas Herrmann]

Booting a 32-bit kernel on Magny-Cours results in the following panic

  ...
  Using APIC driver default
  ...
  Overriding APIC driver with bigsmp
  ...
  Getting VERSION: 80050010
  Getting VERSION: 80050010
  Getting ID: 10000000
  Getting ID: ef000000
  Getting LVT0: 700
  Getting LVT1: 10000
  Kernel panic - not syncing: Boot APIC ID in local APIC unexpected (16 vs 0)
  Pid: 1, comm: swapper Not tainted 2.6.30-rcX #2
  Call Trace:
   [<c05194da>] ? panic+0x38/0xd3
   [<c0743102>] ? native_smp_prepare_cpus+0x259/0x31f
   [<c073b19d>] ? kernel_init+0x3e/0x141
   [<c073b15f>] ? kernel_init+0x0/0x141
   [<c020325f>] ? kernel_thread_helper+0x7/0x10

The reason is that default_get_apic_id handled extension of local APIC
ID field just in case of XAPIC.

Thus for this AMD CPU, default_get_apic_id() returns 0 and
bigsmp_get_apic_id() returns 16 which leads to the respective kernel
panic.

This patch introduces a Linux specific feature flag to indicate
support for extended APIC id (8 bits instead of 4 bits width) and sets
the flag on AMD CPUs if applicable.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
---
 arch/x86/include/asm/apic.h       |    2 +-
 arch/x86/include/asm/cpufeature.h |    1 +
 arch/x86/kernel/cpu/amd.c         |   10 ++++++++++
 3 files changed, 12 insertions(+), 1 deletions(-)

Slightly modified changelog in comparision to v2.

Regards,
Andreas


diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 42f2f83..9b2c049 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -410,7 +410,7 @@ static inline unsigned default_get_apic_id(unsigned long x)
 {
 	unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
 
-	if (APIC_XAPIC(ver))
+	if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID))
 		return (x >> 24) & 0xFF;
 	else
 		return (x >> 24) & 0x0F;
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index bb83b1c..78dee4f 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -94,6 +94,7 @@
 #define X86_FEATURE_TSC_RELIABLE (3*32+23) /* TSC is known to be reliable */
 #define X86_FEATURE_NONSTOP_TSC	(3*32+24) /* TSC does not stop in C states */
 #define X86_FEATURE_CLFLUSH_MONITOR (3*32+25) /* "" clflush reqd with monitor */
+#define X86_FEATURE_EXTD_APICID	(3*32+26) /* has extended APICID (8 bits) */
 
 /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
 #define X86_FEATURE_XMM3	(4*32+ 0) /* "pni" SSE-3 */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 7e4a459..0802e15 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -6,6 +6,7 @@
 #include <asm/processor.h>
 #include <asm/apic.h>
 #include <asm/cpu.h>
+#include <asm/pci-direct.h>
 
 #ifdef CONFIG_X86_64
 # include <asm/numa_64.h>
@@ -351,6 +352,15 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
 		    (c->x86_model == 8 && c->x86_mask >= 8))
 			set_cpu_cap(c, X86_FEATURE_K6_MTRR);
 #endif
+#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
+	/* check CPU config space for extended APIC ID */
+	if (c->x86 >= 0xf) {
+		unsigned int val;
+		val = read_pci_config(0, 24, 0, 0x68);
+		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
+			set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
+	}
+#endif
 }
 
 static void __cpuinit init_amd(struct cpuinfo_x86 *c)
-- 
1.6.3.1

[tip:x86/urgent] x86: Detect use of extended APIC ID for AMD CPUs

[tip-bot for Andreas Herrmann]

Commit-ID:  42937e81a82b6bbc51a309c83da140b3a7ca5945
Gitweb:     http://git.kernel.org/tip/42937e81a82b6bbc51a309c83da140b3a7ca5945
Author:     Andreas Herrmann <andreas.herrmann3@amd.com>
AuthorDate: Mon, 8 Jun 2009 15:55:09 +0200
Committer:  Ingo Molnar <mingo@elte.hu>
CommitDate: Tue, 9 Jun 2009 15:28:46 +0200

x86: Detect use of extended APIC ID for AMD CPUs

Booting a 32-bit kernel on Magny-Cours results in the following panic:

  ...
  Using APIC driver default
  ...
  Overriding APIC driver with bigsmp
  ...
  Getting VERSION: 80050010
  Getting VERSION: 80050010
  Getting ID: 10000000
  Getting ID: ef000000
  Getting LVT0: 700
  Getting LVT1: 10000
  Kernel panic - not syncing: Boot APIC ID in local APIC unexpected (16 vs 0)
  Pid: 1, comm: swapper Not tainted 2.6.30-rcX #2
  Call Trace:
   [<c05194da>] ? panic+0x38/0xd3
   [<c0743102>] ? native_smp_prepare_cpus+0x259/0x31f
   [<c073b19d>] ? kernel_init+0x3e/0x141
   [<c073b15f>] ? kernel_init+0x0/0x141
   [<c020325f>] ? kernel_thread_helper+0x7/0x10

The reason is that default_get_apic_id handled extension of local APIC
ID field just in case of XAPIC.

Thus for this AMD CPU, default_get_apic_id() returns 0 and
bigsmp_get_apic_id() returns 16 which leads to the respective kernel
panic.

This patch introduces a Linux specific feature flag to indicate
support for extended APIC id (8 bits instead of 4 bits width) and sets
the flag on AMD CPUs if applicable.

Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Cc: <stable@kernel.org>
LKML-Reference: <20090608135509.GA12431@alberich.amd.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>


---
 arch/x86/include/asm/apic.h       |    2 +-
 arch/x86/include/asm/cpufeature.h |    1 +
 arch/x86/kernel/cpu/amd.c         |   10 ++++++++++
 3 files changed, 12 insertions(+), 1 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 42f2f83..9b2c049 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -410,7 +410,7 @@ static inline unsigned default_get_apic_id(unsigned long x)
 {
 	unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
 
-	if (APIC_XAPIC(ver))
+	if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID))
 		return (x >> 24) & 0xFF;
 	else
 		return (x >> 24) & 0x0F;
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index bb83b1c..78dee4f 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -94,6 +94,7 @@
 #define X86_FEATURE_TSC_RELIABLE (3*32+23) /* TSC is known to be reliable */
 #define X86_FEATURE_NONSTOP_TSC	(3*32+24) /* TSC does not stop in C states */
 #define X86_FEATURE_CLFLUSH_MONITOR (3*32+25) /* "" clflush reqd with monitor */
+#define X86_FEATURE_EXTD_APICID	(3*32+26) /* has extended APICID (8 bits) */
 
 /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
 #define X86_FEATURE_XMM3	(4*32+ 0) /* "pni" SSE-3 */
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 7e4a459..0802e15 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -6,6 +6,7 @@
 #include <asm/processor.h>
 #include <asm/apic.h>
 #include <asm/cpu.h>
+#include <asm/pci-direct.h>
 
 #ifdef CONFIG_X86_64
 # include <asm/numa_64.h>
@@ -351,6 +352,15 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
 		    (c->x86_model == 8 && c->x86_mask >= 8))
 			set_cpu_cap(c, X86_FEATURE_K6_MTRR);
 #endif
+#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
+	/* check CPU config space for extended APIC ID */
+	if (c->x86 >= 0xf) {
+		unsigned int val;
+		val = read_pci_config(0, 24, 0, 0x68);
+		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))
+			set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
+	}
+#endif
 }
 
 static void __cpuinit init_amd(struct cpuinfo_x86 *c)

Re: [PATCH] x86: detect use of extended APIC ID for AMD CPUs

[Bastian Blank]

On Thu, Jun 04, 2009 at 12:40:16PM +0200, Andreas Herrmann wrote:
> Booting a 32-bit kernel on Magny-Cours results in the following panic

This patch breaks Xen really bad. It uses read_pci_config without
knowing that there is something accessible. Also read_pci_config does
not define fault handlers.

| (XEN) traps.c:413:d375 Unhandled general protection fault fault/trap [#13] on VCPU 0 [ec=0000]
| (XEN) domain_crash_sync called from entry.S
| (XEN) Domain 375 (vcpu#0) crashed on cpu#1:
| (XEN) ----[ Xen-3.2-1  x86_64  debug=n  Not tainted ]----
| (XEN) CPU:    1
| (XEN) RIP:    e033:[<ffffffff80401d6b>]
| (XEN) RFLAGS: 0000000000000282   CONTEXT: guest
| (XEN) rax: 000000008000c068   rbx: ffffffff80618a40   rcx: 0000000000000068
| (XEN) rdx: 0000000000000cf8   rsi: 000000000000c000   rdi: 0000000000000000
| (XEN) rbp: 0000000000000018   rsp: ffffffff80621eb0   r8:  ffffffff80621efc
| (XEN) r9:  00000000ffffffff   r10: ffffffff80621ef8   r11: 00000000ffffffff
| (XEN) r12: ffffffffffffffff   r13: ffffffff80621fd8   r14: 0000002040404030
| (XEN) r15: 00000000015bb600   cr0: 000000008005003b   cr4: 00000000000006f0
| (XEN) cr3: 00000002077be000   cr2: 000000204316b000
| (XEN) ds: 0000   es: 0000   fs: 0000   gs: 0000   ss: e02b   cs: e033
| (XEN) Guest stack trace from rsp=ffffffff80621eb0:
| (XEN)    0000000000000068 00000000ffffffff 0000000000000000 ffffffff80401d6b
| (XEN)    000000010000e030 0000000000010082 ffffffff80621ef0 000000000000e02b
| (XEN)    ffffffff804aeb3a 0000000100000000 0000302800000000 ffffffff805bcb20
| (XEN)    ffffffff80651552 0000000000000000 0000000000000000 0000000000fdfd88
| (XEN)    ffffffff8064e47c 0000000001fb9000 ffffffff80545875 0000000000000800
| (XEN)    0000000000002c00 ffffffff81fb9000 ffffffff80650026 ffffffff805ca1c0

| ffffffff80401d44 T read_pci_config
| ffffffff804aeb41 t early_init_amd

I see several ways to fix this:
- Define fault handlers for *_pci_config
- Check for Xen
- Disable early PCI access from Xen if running unpriviledged and check
  that in either in *_pci_config or early_init_amd

Bastian

-- 
Insults are effective only where emotion is present.
		-- Spock, "Who Mourns for Adonais?"  stardate 3468.1

Re: [PATCH] x86: detect use of extended APIC ID for AMD CPUs

[Bastian Blank]

On Thu, Jun 04, 2009 at 12:40:16PM +0200, Andreas Herrmann wrote:
> Booting a 32-bit kernel on Magny-Cours results in the following panic

This patch breaks Xen really bad. It uses read_pci_config without
knowing that there is something accessible. Also read_pci_config does
not define fault handlers.

| (XEN) traps.c:413:d375 Unhandled general protection fault fault/trap [#13] on VCPU 0 [ec=0000]
| (XEN) domain_crash_sync called from entry.S
| (XEN) Domain 375 (vcpu#0) crashed on cpu#1:
| (XEN) ----[ Xen-3.2-1  x86_64  debug=n  Not tainted ]----
| (XEN) CPU:    1
| (XEN) RIP:    e033:[<ffffffff80401d6b>]
| (XEN) RFLAGS: 0000000000000282   CONTEXT: guest
| (XEN) rax: 000000008000c068   rbx: ffffffff80618a40   rcx: 0000000000000068
| (XEN) rdx: 0000000000000cf8   rsi: 000000000000c000   rdi: 0000000000000000
| (XEN) rbp: 0000000000000018   rsp: ffffffff80621eb0   r8:  ffffffff80621efc
| (XEN) r9:  00000000ffffffff   r10: ffffffff80621ef8   r11: 00000000ffffffff
| (XEN) r12: ffffffffffffffff   r13: ffffffff80621fd8   r14: 0000002040404030
| (XEN) r15: 00000000015bb600   cr0: 000000008005003b   cr4: 00000000000006f0
| (XEN) cr3: 00000002077be000   cr2: 000000204316b000
| (XEN) ds: 0000   es: 0000   fs: 0000   gs: 0000   ss: e02b   cs: e033
| (XEN) Guest stack trace from rsp=ffffffff80621eb0:
| (XEN)    0000000000000068 00000000ffffffff 0000000000000000 ffffffff80401d6b
| (XEN)    000000010000e030 0000000000010082 ffffffff80621ef0 000000000000e02b
| (XEN)    ffffffff804aeb3a 0000000100000000 0000302800000000 ffffffff805bcb20
| (XEN)    ffffffff80651552 0000000000000000 0000000000000000 0000000000fdfd88
| (XEN)    ffffffff8064e47c 0000000001fb9000 ffffffff80545875 0000000000000800
| (XEN)    0000000000002c00 ffffffff81fb9000 ffffffff80650026 ffffffff805ca1c0

| ffffffff80401d44 T read_pci_config
| ffffffff804aeb41 t early_init_amd

I see several ways to fix this:
- Define fault handlers for *_pci_config
- Check for Xen
- Disable early PCI access from Xen if running unpriviledged and check
  that in either in *_pci_config or early_init_amd

Bastian

-- 
Insults are effective only where emotion is present.
		-- Spock, "Who Mourns for Adonais?"  stardate 3468.1

Re: [PATCH] x86: detect use of extended APIC ID for AMD CPUs

[Jeremy Fitzhardinge]

On 07/21/09 03:36, Bastian Blank wrote:
> On Thu, Jun 04, 2009 at 12:40:16PM +0200, Andreas Herrmann wrote:
>   
>> Booting a 32-bit kernel on Magny-Cours results in the following panic
>>     
>
> This patch breaks Xen really bad. It uses read_pci_config without
> knowing that there is something accessible. Also read_pci_config does
> not define fault handlers.
>
> | (XEN) traps.c:413:d375 Unhandled general protection fault fault/trap [#13] on VCPU 0 [ec=0000]
> | (XEN) domain_crash_sync called from entry.S
> | (XEN) Domain 375 (vcpu#0) crashed on cpu#1:
> | (XEN) ----[ Xen-3.2-1  x86_64  debug=n  Not tainted ]----
> | (XEN) CPU:    1
> | (XEN) RIP:    e033:[<ffffffff80401d6b>]
> | (XEN) RFLAGS: 0000000000000282   CONTEXT: guest
> | (XEN) rax: 000000008000c068   rbx: ffffffff80618a40   rcx: 0000000000000068
> | (XEN) rdx: 0000000000000cf8   rsi: 000000000000c000   rdi: 0000000000000000
> | (XEN) rbp: 0000000000000018   rsp: ffffffff80621eb0   r8:  ffffffff80621efc
> | (XEN) r9:  00000000ffffffff   r10: ffffffff80621ef8   r11: 00000000ffffffff
> | (XEN) r12: ffffffffffffffff   r13: ffffffff80621fd8   r14: 0000002040404030
> | (XEN) r15: 00000000015bb600   cr0: 000000008005003b   cr4: 00000000000006f0
> | (XEN) cr3: 00000002077be000   cr2: 000000204316b000
> | (XEN) ds: 0000   es: 0000   fs: 0000   gs: 0000   ss: e02b   cs: e033
> | (XEN) Guest stack trace from rsp=ffffffff80621eb0:
> | (XEN)    0000000000000068 00000000ffffffff 0000000000000000 ffffffff80401d6b
> | (XEN)    000000010000e030 0000000000010082 ffffffff80621ef0 000000000000e02b
> | (XEN)    ffffffff804aeb3a 0000000100000000 0000302800000000 ffffffff805bcb20
> | (XEN)    ffffffff80651552 0000000000000000 0000000000000000 0000000000fdfd88
> | (XEN)    ffffffff8064e47c 0000000001fb9000 ffffffff80545875 0000000000000800
> | (XEN)    0000000000002c00 ffffffff81fb9000 ffffffff80650026 ffffffff805ca1c0
>
> | ffffffff80401d44 T read_pci_config
> | ffffffff804aeb41 t early_init_amd
>
> I see several ways to fix this:
> - Define fault handlers for *_pci_config
> - Check for Xen
> - Disable early PCI access from Xen if running unpriviledged and check
>   that in either in *_pci_config or early_init_amd
>
>   

I assume "d375" is a domU.  cpu_has_apic should be false, and this code
shouldn't be running if the CPU has no (visible) apic.

Does this work?  (Completely untested.)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 28e5f59..e2485b0 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -356,7 +356,7 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
 #endif
 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
 	/* check CPU config space for extended APIC ID */
-	if (c->x86 >= 0xf) {
+	if (cpu_has_apic && c->x86 >= 0xf) {
 		unsigned int val;
 		val = read_pci_config(0, 24, 0, 0x68);
 		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))


	J

Re: [PATCH] x86: detect use of extended APIC ID for AMD CPUs

[Jeremy Fitzhardinge]

On 07/21/09 03:36, Bastian Blank wrote:
> On Thu, Jun 04, 2009 at 12:40:16PM +0200, Andreas Herrmann wrote:
>   
>> Booting a 32-bit kernel on Magny-Cours results in the following panic
>>     
>
> This patch breaks Xen really bad. It uses read_pci_config without
> knowing that there is something accessible. Also read_pci_config does
> not define fault handlers.
>
> | (XEN) traps.c:413:d375 Unhandled general protection fault fault/trap [#13] on VCPU 0 [ec=0000]
> | (XEN) domain_crash_sync called from entry.S
> | (XEN) Domain 375 (vcpu#0) crashed on cpu#1:
> | (XEN) ----[ Xen-3.2-1  x86_64  debug=n  Not tainted ]----
> | (XEN) CPU:    1
> | (XEN) RIP:    e033:[<ffffffff80401d6b>]
> | (XEN) RFLAGS: 0000000000000282   CONTEXT: guest
> | (XEN) rax: 000000008000c068   rbx: ffffffff80618a40   rcx: 0000000000000068
> | (XEN) rdx: 0000000000000cf8   rsi: 000000000000c000   rdi: 0000000000000000
> | (XEN) rbp: 0000000000000018   rsp: ffffffff80621eb0   r8:  ffffffff80621efc
> | (XEN) r9:  00000000ffffffff   r10: ffffffff80621ef8   r11: 00000000ffffffff
> | (XEN) r12: ffffffffffffffff   r13: ffffffff80621fd8   r14: 0000002040404030
> | (XEN) r15: 00000000015bb600   cr0: 000000008005003b   cr4: 00000000000006f0
> | (XEN) cr3: 00000002077be000   cr2: 000000204316b000
> | (XEN) ds: 0000   es: 0000   fs: 0000   gs: 0000   ss: e02b   cs: e033
> | (XEN) Guest stack trace from rsp=ffffffff80621eb0:
> | (XEN)    0000000000000068 00000000ffffffff 0000000000000000 ffffffff80401d6b
> | (XEN)    000000010000e030 0000000000010082 ffffffff80621ef0 000000000000e02b
> | (XEN)    ffffffff804aeb3a 0000000100000000 0000302800000000 ffffffff805bcb20
> | (XEN)    ffffffff80651552 0000000000000000 0000000000000000 0000000000fdfd88
> | (XEN)    ffffffff8064e47c 0000000001fb9000 ffffffff80545875 0000000000000800
> | (XEN)    0000000000002c00 ffffffff81fb9000 ffffffff80650026 ffffffff805ca1c0
>
> | ffffffff80401d44 T read_pci_config
> | ffffffff804aeb41 t early_init_amd
>
> I see several ways to fix this:
> - Define fault handlers for *_pci_config
> - Check for Xen
> - Disable early PCI access from Xen if running unpriviledged and check
>   that in either in *_pci_config or early_init_amd
>
>   

I assume "d375" is a domU.  cpu_has_apic should be false, and this code
shouldn't be running if the CPU has no (visible) apic.

Does this work?  (Completely untested.)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 28e5f59..e2485b0 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -356,7 +356,7 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
 #endif
 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
 	/* check CPU config space for extended APIC ID */
-	if (c->x86 >= 0xf) {
+	if (cpu_has_apic && c->x86 >= 0xf) {
 		unsigned int val;
 		val = read_pci_config(0, 24, 0, 0x68);
 		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))


	J

Re: [PATCH] x86: detect use of extended APIC ID for AMD CPUs

[Bastian Blank]

On Tue, Jul 21, 2009 at 09:56:45AM -0700, Jeremy Fitzhardinge wrote:
> Does this work?  (Completely untested.)

Yes, it works. It just looks like a workaround.

Bastian

-- 
Each kiss is as the first.
		-- Miramanee, Kirk's wife, "The Paradise Syndrome",
		   stardate 4842.6

Re: [PATCH] x86: detect use of extended APIC ID for AMD CPUs

[Thomas Gleixner]

On Wed, 22 Jul 2009, Bastian Blank wrote:

> On Tue, Jul 21, 2009 at 09:56:45AM -0700, Jeremy Fitzhardinge wrote:
> > Does this work?  (Completely untested.)
> 
> Yes, it works. It just looks like a workaround.

No, it looks fine. Jeremy, can you please send it again with a proper
changelog.

Thanks,

	tglx

[PATCH] x86/amd: don't probe for extended APIC ID if APICs are disabled

[Jeremy Fitzhardinge]

If we've logically disabled apics, don't probe the PCI space for the
AMD extended APIC ID.

[ Impact: prevent boot crash under Xen. ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Reported-by: Bastian Blank <bastian@waldi.eu.org>

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 28e5f59..e2485b0 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -356,7 +356,7 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
 #endif
 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
 	/* check CPU config space for extended APIC ID */
-	if (c->x86 >= 0xf) {
+	if (cpu_has_apic && c->x86 >= 0xf) {
 		unsigned int val;
 		val = read_pci_config(0, 24, 0, 0x68);
 		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))

[PATCH] x86/amd: don't probe for extended APIC ID if APICs are disabled

[Jeremy Fitzhardinge]

If we've logically disabled apics, don't probe the PCI space for the
AMD extended APIC ID.

[ Impact: prevent boot crash under Xen. ]

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Reported-by: Bastian Blank <bastian@waldi.eu.org>

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 28e5f59..e2485b0 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -356,7 +356,7 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
 #endif
 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
 	/* check CPU config space for extended APIC ID */
-	if (c->x86 >= 0xf) {
+	if (cpu_has_apic && c->x86 >= 0xf) {
 		unsigned int val;
 		val = read_pci_config(0, 24, 0, 0x68);
 		if ((val & ((1 << 17) | (1 << 18))) == ((1 << 17) | (1 << 18)))