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[patch 1/2] x86, apic: use physical mode for IBM summit platforms

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Suresh Siddha

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Jan 18, 2010, 3:30:01 PM1/18/10
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ibm_summit_oem_check_for_x64.patch

Suresh Siddha

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Jan 18, 2010, 3:30:02 PM1/18/10
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use_flat_mode_for_upto_8_logical_cpus.patch

tip-bot for Suresh Siddha

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Feb 9, 2010, 1:10:03 PM2/9/10
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Commit-ID: 418f727639cfc8f03068aae09f473c493c759b9b
Gitweb: http://git.kernel.org/tip/418f727639cfc8f03068aae09f473c493c759b9b
Author: Suresh Siddha <suresh....@intel.com>
AuthorDate: Tue, 9 Feb 2010 09:18:35 -0800
Committer: H. Peter Anvin <h...@zytor.com>
CommitDate: Tue, 9 Feb 2010 09:29:17 -0800

x86, apic: Don't use logical-flat mode when CPU hotplug may exceed 8 CPUs

We need to fall back from logical-flat APIC mode to physical-flat mode
when we have more than 8 CPUs. However, in the presence of CPU
hotplug, we have to consider the number of possible CPUs rather than
the number of current CPUs; otherwise we may cross the 8-CPU boundary
when CPUs are added later.

Reported-by: Shaohui Zheng <shaohu...@intel.com>
Acked-by: Shaohui Zheng <shaohu...@intel.com>
Cc: Yinghai Lu <yin...@kernel.org>
LKML-Reference: <201001182012...@sbs-t61.sc.intel.com>
Signed-off-by: H. Peter Anvin <h...@zytor.com>
Cc: <sta...@kernel.org>
---
arch/x86/kernel/apic/apic.c | 2 +-
arch/x86/kernel/apic/probe_64.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 3987e44..fc1d579 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1892,7 +1892,7 @@ void __cpuinit generic_processor_info(int apicid, int version)
max_physical_apicid = apicid;

#ifdef CONFIG_X86_32
- if (num_processors > 8) {
+ if (num_possible_cpus() > 8) {
switch (boot_cpu_data.x86_vendor) {
case X86_VENDOR_INTEL:
if (!APIC_XAPIC(version)) {
diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c
index 450fe20..83e9be4 100644
--- a/arch/x86/kernel/apic/probe_64.c
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -67,7 +67,7 @@ void __init default_setup_apic_routing(void)
}
#endif

- if (apic == &apic_flat && num_processors > 8)
+ if (apic == &apic_flat && num_possible_cpus() > 8)
apic = &apic_physflat;

printk(KERN_INFO "Setting APIC routing to %s\n", apic->name);
--
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Yinghai Lu

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Feb 9, 2010, 1:50:01 PM2/9/10
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for 32bit you can not use this function yet.
that only can be used after prefill_possible_map()

> switch (boot_cpu_data.x86_vendor) {
> case X86_VENDOR_INTEL:
> if (!APIC_XAPIC(version)) {
> diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c
> index 450fe20..83e9be4 100644
> --- a/arch/x86/kernel/apic/probe_64.c
> +++ b/arch/x86/kernel/apic/probe_64.c
> @@ -67,7 +67,7 @@ void __init default_setup_apic_routing(void)
> }
> #endif
>
> - if (apic == &apic_flat && num_processors > 8)
> + if (apic == &apic_flat && num_possible_cpus() > 8)
> apic = &apic_physflat;
>
> printk(KERN_INFO "Setting APIC routing to %s\n", apic->name);

please check
http://patchwork.kernel.org/patch/74536/
http://patchwork.kernel.org/patch/74533/
http://patchwork.kernel.org/patch/74525/
http://patchwork.kernel.org/patch/74524/

YH

Suresh Siddha

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Feb 9, 2010, 9:10:02 PM2/9/10
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On Tue, 2010-02-09 at 10:47 -0800, Yinghai Lu wrote:
> > #ifdef CONFIG_X86_32
> > - if (num_processors > 8) {
> > + if (num_possible_cpus() > 8) {
>
> for 32bit you can not use this function yet.
> that only can be used after prefill_possible_map()

Yinghai, Agreed. How about the appended patch? I tested and it works.
Peter wants a small quick fix for this issue (to resolve the boot issue
reported in the virtualization guest context) so that we can queue it
for .33 and .32 kernels (as some distributions will be based on these
kernels).

Can you please Ack if it is ok?

thanks,
suresh
---

From: Suresh Siddha <suresh....@intel.com>
Subject: x86, apic: Don't use logical-flat mode when CPU hotplug may exceed 8 CPUs

We need to fall back from logical-flat APIC mode to physical-flat mode
when we have more than 8 CPUs. However, in the presence of CPU

hotplug(with bios listing not enabled but possible cpus as disabled cpus in
MADT), we have to consider the number of possible CPUs rather than


the number of current CPUs; otherwise we may cross the 8-CPU boundary
when CPUs are added later.

32bit apic code can use more cleanups (like the removal of vendor checks in
32bit default_setup_apic_routing()) and more unifications with 64bit code.
Yinghai has some patches in works already. This patch addresses the boot issue
that is reported in the virtualization guest context.

Signed-off-by: Suresh Siddha <suresh....@intel.com>
Acked-by: Shaohui Zheng <shaohu...@intel.com>
Cc: <sta...@kernel.org>
---

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 036d28a..0acbcdf 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1185,9 +1185,6 @@ static void __init acpi_process_madt(void)
if (!error) {
acpi_lapic = 1;

-#ifdef CONFIG_X86_BIGSMP
- generic_bigsmp_probe();
-#endif
/*
* Parse MADT IO-APIC entries
*/
@@ -1197,8 +1194,6 @@ static void __init acpi_process_madt(void)
acpi_ioapic = 1;

smp_found_config = 1;
- if (apic->setup_apic_routing)
- apic->setup_apic_routing();
}
}
if (error == -EINVAL) {
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index a85f216..6e29b2a 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1641,9 +1641,7 @@ int __init APIC_init_uniprocessor(void)
#endif

enable_IR_x2apic();
-#ifdef CONFIG_X86_64
default_setup_apic_routing();
-#endif

verify_local_APIC();
connect_bsp_APIC();
@@ -1891,21 +1889,6 @@ void __cpuinit generic_processor_info(int apicid, int version)
if (apicid > max_physical_apicid)
max_physical_apicid = apicid;

-#ifdef CONFIG_X86_32
- if (num_processors > 8) {
- switch (boot_cpu_data.x86_vendor) {
- case X86_VENDOR_INTEL:
- if (!APIC_XAPIC(version)) {
- def_to_bigsmp = 0;
- break;
- }
- /* If P4 and above fall through */
- case X86_VENDOR_AMD:
- def_to_bigsmp = 1;
- }
- }
-#endif
-
#if defined(CONFIG_SMP) || defined(CONFIG_X86_64)
early_per_cpu(x86_cpu_to_apicid, cpu) = apicid;
early_per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
diff --git a/arch/x86/kernel/apic/probe_32.c b/arch/x86/kernel/apic/probe_32.c
index 1a6559f..88e78ae 100644
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -54,6 +54,31 @@ late_initcall(print_ipi_mode);

void default_setup_apic_routing(void)
{
+ int version = apic_version[boot_cpu_physical_apicid];
+
+ if (num_possible_cpus() > 8) {
+ switch (boot_cpu_data.x86_vendor) {
+ case X86_VENDOR_INTEL:
+ if (!APIC_XAPIC(version)) {
+ def_to_bigsmp = 0;
+ break;
+ }
+ /* If P4 and above fall through */
+ case X86_VENDOR_AMD:
+ def_to_bigsmp = 1;
+ }
+ }
+
+#ifdef CONFIG_X86_BIGSMP
+ generic_bigsmp_probe();
+#endif
+
+ if (apic->setup_apic_routing)
+ apic->setup_apic_routing();
+}
+
+void setup_apic_flat_routing(void)
+{
#ifdef CONFIG_X86_IO_APIC
printk(KERN_INFO
"Enabling APIC mode: Flat. Using %d I/O APICs\n",
@@ -103,7 +128,7 @@ struct apic apic_default = {
.init_apic_ldr = default_init_apic_ldr,

.ioapic_phys_id_map = default_ioapic_phys_id_map,
- .setup_apic_routing = default_setup_apic_routing,
+ .setup_apic_routing = setup_apic_flat_routing,
.multi_timer_check = NULL,
.apicid_to_node = default_apicid_to_node,
.cpu_to_logical_apicid = default_cpu_to_logical_apicid,


diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c
index 450fe20..83e9be4 100644
--- a/arch/x86/kernel/apic/probe_64.c
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -67,7 +67,7 @@ void __init default_setup_apic_routing(void)
}
#endif

- if (apic == &apic_flat && num_processors > 8)
+ if (apic == &apic_flat && num_possible_cpus() > 8)
apic = &apic_physflat;

printk(KERN_INFO "Setting APIC routing to %s\n", apic->name);

diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index 40b54ce..a2c1edd 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -359,13 +359,6 @@ static int __init smp_read_mpc(struct mpc_table *mpc, unsigned early)
x86_init.mpparse.mpc_record(1);
}

-#ifdef CONFIG_X86_BIGSMP
- generic_bigsmp_probe();
-#endif
-
- if (apic->setup_apic_routing)
- apic->setup_apic_routing();
-
if (!num_processors)
printk(KERN_ERR "MPTABLE: no processors registered!\n");
return num_processors;
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index b2ebcba..c08829a 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1087,9 +1087,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)
set_cpu_sibling_map(0);

enable_IR_x2apic();
-#ifdef CONFIG_X86_64
default_setup_apic_routing();
-#endif

if (smp_sanity_check(max_cpus) < 0) {
printk(KERN_INFO "SMP disabled\n");

Yinghai Lu

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Feb 9, 2010, 9:30:01 PM2/9/10
to

the main difference between this patch and
http://patchwork.kernel.org/patch/74525/

is moving apic->setup_apic_routing calling.

wonder if it will affect subarch other than logical flat and physical flat.

YH

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Yinghai Lu

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Feb 9, 2010, 10:10:01 PM2/9/10
to

other subarch setup_apic_routing is just pr_info...

so your patch should be ok.

YH

Yinghai Lu

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Feb 9, 2010, 10:20:02 PM2/9/10
to
On 02/09/2010 07:03 PM, H. Peter Anvin wrote:

> On 02/09/2010 07:00 PM, Yinghai Lu wrote:
>>
>> other subarch setup_apic_routing is just pr_info...
>>
>> so your patch should be ok.
>>
>
> Great, can I take that as an Acked-by: or Reviewed-by: from you?
>
sure.

H. Peter Anvin

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Feb 9, 2010, 10:20:02 PM2/9/10
to
On 02/09/2010 07:00 PM, Yinghai Lu wrote:
>
> other subarch setup_apic_routing is just pr_info...
>
> so your patch should be ok.
>

Great, can I take that as an Acked-by: or Reviewed-by: from you?

I really appreciate the review.

-hpa

Yinghai Lu

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Feb 9, 2010, 10:50:01 PM2/9/10
to
On 02/09/2010 06:01 PM, Suresh Siddha wrote:

__init

> {
> + int version = apic_version[boot_cpu_physical_apicid];
> +
> + if (num_possible_cpus() > 8) {
> + switch (boot_cpu_data.x86_vendor) {
> + case X86_VENDOR_INTEL:
> + if (!APIC_XAPIC(version)) {
> + def_to_bigsmp = 0;
> + break;
> + }
> + /* If P4 and above fall through */
> + case X86_VENDOR_AMD:
> + def_to_bigsmp = 1;
> + }
> + }
> +
> +#ifdef CONFIG_X86_BIGSMP
> + generic_bigsmp_probe();
> +#endif
> +
> + if (apic->setup_apic_routing)
> + apic->setup_apic_routing();
> +}
> +
> +void setup_apic_flat_routing(void)

static?

YH

tip-bot for Suresh Siddha

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Feb 10, 2010, 1:30:02 AM2/10/10
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Commit-ID: 681ee44d40d7c93b42118320e4620d07d8704fd6
Gitweb: http://git.kernel.org/tip/681ee44d40d7c93b42118320e4620d07d8704fd6
Author: Suresh Siddha <suresh....@intel.com>
AuthorDate: Tue, 9 Feb 2010 18:01:44 -0800

Committer: H. Peter Anvin <h...@zytor.com>
CommitDate: Tue, 9 Feb 2010 20:51:11 -0800

x86, apic: Don't use logical-flat mode when CPU hotplug may exceed 8 CPUs

We need to fall back from logical-flat APIC mode to physical-flat mode
when we have more than 8 CPUs. However, in the presence of CPU
hotplug(with bios listing not enabled but possible cpus as disabled cpus in
MADT), we have to consider the number of possible CPUs rather than
the number of current CPUs; otherwise we may cross the 8-CPU boundary
when CPUs are added later.

32bit apic code can use more cleanups (like the removal of vendor checks in
32bit default_setup_apic_routing()) and more unifications with 64bit code.
Yinghai has some patches in works already. This patch addresses the boot issue
that is reported in the virtualization guest context.

[ hpa: incorporated function annotation feedback from Yinghai Lu ]

Signed-off-by: Suresh Siddha <suresh....@intel.com>
LKML-Reference: <1265767304.2...@sbs-t61.sc.intel.com>
Acked-by: Shaohui Zheng <shaohu...@intel.com>
Reviewed-by: Yinghai Lu <yin...@kernel.org>
Cc: <sta...@kernel.org>


Signed-off-by: H. Peter Anvin <h...@zytor.com>

---
arch/x86/kernel/acpi/boot.c | 5 -----
arch/x86/kernel/apic/apic.c | 17 -----------------
arch/x86/kernel/apic/probe_32.c | 29 +++++++++++++++++++++++++++--
arch/x86/kernel/apic/probe_64.c | 2 +-
arch/x86/kernel/mpparse.c | 7 -------
arch/x86/kernel/smpboot.c | 2 --
6 files changed, 28 insertions(+), 34 deletions(-)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 036d28a..0acbcdf 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1185,9 +1185,6 @@ static void __init acpi_process_madt(void)
if (!error) {
acpi_lapic = 1;

-#ifdef CONFIG_X86_BIGSMP
- generic_bigsmp_probe();
-#endif
/*
* Parse MADT IO-APIC entries
*/
@@ -1197,8 +1194,6 @@ static void __init acpi_process_madt(void)
acpi_ioapic = 1;

smp_found_config = 1;
- if (apic->setup_apic_routing)
- apic->setup_apic_routing();
}
}
if (error == -EINVAL) {
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c

index 3987e44..dfca210 100644

index 1a6559f..99d2fe0 100644
--- a/arch/x86/kernel/apic/probe_32.c
+++ b/arch/x86/kernel/apic/probe_32.c
@@ -52,7 +52,32 @@ static int __init print_ipi_mode(void)
}
late_initcall(print_ipi_mode);

-void default_setup_apic_routing(void)
+void __init default_setup_apic_routing(void)
+{


+ int version = apic_version[boot_cpu_physical_apicid];
+
+ if (num_possible_cpus() > 8) {
+ switch (boot_cpu_data.x86_vendor) {
+ case X86_VENDOR_INTEL:
+ if (!APIC_XAPIC(version)) {
+ def_to_bigsmp = 0;
+ break;
+ }
+ /* If P4 and above fall through */
+ case X86_VENDOR_AMD:
+ def_to_bigsmp = 1;
+ }
+ }
+
+#ifdef CONFIG_X86_BIGSMP
+ generic_bigsmp_probe();
+#endif
+
+ if (apic->setup_apic_routing)
+ apic->setup_apic_routing();
+}
+

+static void setup_apic_flat_routing(void)
{
#ifdef CONFIG_X86_IO_APIC
printk(KERN_INFO

index 678d0b8..b4e870c 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1083,9 +1083,7 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus)

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