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x86: clean up setup_clear/force_cpu_cap handling

PATCH In review Yinghai Lu 3 participants 5 messages Dec 23, 2008 – Dec 28, 2008 x86

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Yinghai Lu

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#0 lore raw

PATCH 1/1 x86: clean up setup_clear/force_cpu_cap handling

Impact: fix and cleanup

setup_force_cpu_cap() only have one user xen
but it should not reuse cleared_cpu_cpus. it will have problem for smp.

need to have cpu_cpus_set array too.
also need to setup handling before all cpus cap AND

Signed-off-by Yinghai Lu <[email protected]>
---
 arch/x86/include/asm/cpufeature.h |    4 ++--
 arch/x86/include/asm/processor.h  |    3 ++-
 arch/x86/kernel/cpu/common.c      |   17 ++++++++++++-----
 3 files changed, 16 insertions(+), 8 deletions(-)
arch/x86/include/asm/cpufeature.h +2 -2
Index: linux-2.6/arch/x86/include/asm/cpufeature.h
===================================================================
@@ -190,11 +190,11 @@ extern const char * const x86_power_flag
 #define clear_cpu_cap(c, bit)	clear_bit(bit, (unsigned long *)((c)->x86_capability))
 #define setup_clear_cpu_cap(bit) do { \
 	clear_cpu_cap(&boot_cpu_data, bit);	\
-	set_bit(bit, (unsigned long *)cleared_cpu_caps); \
+	set_bit(bit, (unsigned long *)cpu_caps_cleared); \
 } while (0)
 #define setup_force_cpu_cap(bit) do { \
 	set_cpu_cap(&boot_cpu_data, bit);	\
-	clear_bit(bit, (unsigned long *)cleared_cpu_caps);	\
+	set_bit(bit, (unsigned long *)cpu_caps_set);	\
 } while (0)
 
 #define cpu_has_fpu		boot_cpu_has(X86_FEATURE_FPU)
arch/x86/include/asm/processor.h +2 -1
Index: linux-2.6/arch/x86/include/asm/processor.h
===================================================================
@@ -134,7 +134,8 @@ extern struct cpuinfo_x86	boot_cpu_data;
 extern struct cpuinfo_x86	new_cpu_data;
 
 extern struct tss_struct	doublefault_tss;
-extern __u32			cleared_cpu_caps[NCAPINTS];
+extern __u32			cpu_caps_cleared[NCAPINTS];
+extern __u32			cpu_caps_set[NCAPINTS];
 
 #ifdef CONFIG_SMP
 DECLARE_PER_CPU(struct cpuinfo_x86, cpu_info);
arch/x86/kernel/cpu/common.c +12 -5
Index: linux-2.6/arch/x86/kernel/cpu/common.c
===================================================================
@@ -221,7 +221,8 @@ static char __cpuinit *table_lookup_mode
 	return NULL;		/* Not found */
 }
 
-__u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata;
+__u32 cpu_caps_cleared[NCAPINTS] __cpuinitdata;
+__u32 cpu_caps_set[NCAPINTS] __cpuinitdata;
 
 /* Current gdt points %fs at the "master" per-cpu area: after this,
  * it's on the real one. */

@@ -706,6 +707,16 @@ static void __cpuinit identify_cpu(struc
 #endif
 
 	init_hypervisor(c);
+
+	/*
+	 * Clear/Set all flags overriden by options, need do it
+	 * before following smp all cpus cap AND.
+	 */
+	for (i = 0; i < NCAPINTS; i++) {
+		c->x86_capability[i] &= ~cpu_caps_cleared[i];
+		c->x86_capability[i] |= cpu_caps_set[i];
+	}
+
 	/*
 	 * On SMP, boot_cpu_data holds the common feature set between
 	 * all CPUs; so make sure that we indicate which features are

@@ -718,10 +729,6 @@ static void __cpuinit identify_cpu(struc
 			boot_cpu_data.x86_capability[i] &= c->x86_capability[i];
 	}
 
-	/* Clear all flags overriden by options */
-	for (i = 0; i < NCAPINTS; i++)
-		c->x86_capability[i] &= ~cleared_cpu_caps[i];
-
 #ifdef CONFIG_X86_MCE
 	/* Init Machine Check Exception if available. */
 	mcheck_init(c);
#1 lore raw
Quoted 9 lines · Yinghai Lu

Impact: fix and cleanup

setup_force_cpu_cap() only have one user xen
but it should not reuse cleared_cpu_cpus. it will have problem for smp.

need to have cpu_cpus_set array too.
also need to setup handling before all cpus cap AND

Quoted 7 lines
Signed-off-by Yinghai Lu <[email protected]>
---
 arch/x86/include/asm/cpufeature.h |    4 ++--
 arch/x86/include/asm/processor.h  |    3 ++-
 arch/x86/kernel/cpu/common.c      |   17 ++++++++++++-----
 3 files changed, 16 insertions(+), 8 deletions(-)

Rusty, you'll carry this patch in your linux-2.6-boot-params.git tree, right? Merging this in the x86 tree would just needlessly complicate your logistics, right?

Ingo

author
#2 lore raw
Quoted 19 lines · Ingo Molnar
Quoted 9 lines · Yinghai Lu

Impact: fix and cleanup

setup_force_cpu_cap() only have one user xen
but it should not reuse cleared_cpu_cpus. it will have problem for smp.

need to have cpu_cpus_set array too.
also need to setup handling before all cpus cap AND

Quoted 7 lines
Signed-off-by Yinghai Lu <[email protected]>
---
 arch/x86/include/asm/cpufeature.h |    4 ++--
 arch/x86/include/asm/processor.h  |    3 ++-
 arch/x86/kernel/cpu/common.c      |   17 ++++++++++++-----
 3 files changed, 16 insertions(+), 8 deletions(-)
Quoted 3 lines

Rusty, you'll carry this patch in your linux-2.6-boot-params.git tree, right? Merging this in the x86 tree would just needlessly complicate your logistics, right?

Rusty polished this patch a little bit and put the updated one in his tree. so you may need to pick up the updated one.

YH

#3 lore raw
In reply to Ingo Molnar
Quoted 20 lines · On Saturday 27 December 2008 20:52:34 Ingo Molnar wrote:
Quoted 9 lines · Yinghai Lu

Impact: fix and cleanup

setup_force_cpu_cap() only have one user xen
but it should not reuse cleared_cpu_cpus. it will have problem for smp.

need to have cpu_cpus_set array too.
also need to setup handling before all cpus cap AND

Quoted 7 lines
Signed-off-by Yinghai Lu <[email protected]>
---
 arch/x86/include/asm/cpufeature.h |    4 ++--
 arch/x86/include/asm/processor.h  |    3 ++-
 arch/x86/kernel/cpu/common.c      |   17 ++++++++++++-----
 3 files changed, 16 insertions(+), 8 deletions(-)
Quoted 3 lines

Rusty, you'll carry this patch in your linux-2.6-boot-params.git tree, right? Merging this in the x86 tree would just needlessly complicate your logistics, right?

Yep, if you're happy to ack, I'm happy to carry.

Cheers,
Rusty.

Acked-by
#4 lore raw
Quoted 21 lines · Rusty Russell
Quoted 20 lines · On Saturday 27 December 2008 20:52:34 Ingo Molnar wrote:
Quoted 16 lines · Yinghai Lu

Impact: fix and cleanup

setup_force_cpu_cap() only have one user xen
but it should not reuse cleared_cpu_cpus. it will have problem for smp.

need to have cpu_cpus_set array too.
also need to setup handling before all cpus cap AND

Signed-off-by Yinghai Lu <[email protected]>
---
 arch/x86/include/asm/cpufeature.h |    4 ++--
 arch/x86/include/asm/processor.h  |    3 ++-
 arch/x86/kernel/cpu/common.c      |   17 ++++++++++++-----
 3 files changed, 16 insertions(+), 8 deletions(-)
Quoted 5 lines
Quoted 3 lines

Rusty, you'll carry this patch in your linux-2.6-boot-params.git tree, right? Merging this in the x86 tree would just needlessly complicate your logistics, right?

Yep, if you're happy to ack, I'm happy to carry.

yeah. And if it breaks, that's your fault ;-)

Acked-by Ingo Molnar <[email protected]>

Ingo