x86: Fix APIC ID sizing bug on larger systems, clean up MAX_APICS confusion
Found one x2apic pre-enabled system, x2apic_mode suddenly get
corrupted after register some cpus, when compiled
CONFIG_NR_CPUS=255 instead of 512.
It turns out that generic_processor_info() ==> phyid_set(apicid,
phys_cpu_present_map) causes the problem.
phys_cpu_present_map is sized by MAX_APICS bits, and pre-enabled
system some cpus have an apic id > 255.
The variable after phys_cpu_present_map may get corrupted
silently:
ffffffff828e8420 B phys_cpu_present_map
ffffffff828e8440 B apic_verbosity
ffffffff828e8444 B local_apic_timer_c2_ok
ffffffff828e8448 B disable_apic
ffffffff828e844c B x2apic_mode
ffffffff828e8450 B x2apic_disabled
ffffffff828e8454 B num_processors
...
Actually phys_cpu_present_map is referenced via apic id, instead
index. We should use MAX_LOCAL_APIC instead MAX_APICS.
For 64-bit it will be 32768 in all cases. BSS will increase by 4k bytes
on 64-bit:
text data bss dec filename
21696943 4193748 12787712 38678403 vmlinux.before
21696943 4193748 12791808 38682499 vmlinux.after
No change on 32bit.
Finally we can remove MAX_APCIS that was rather confusing.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
LKML-Reference: <4D23BD9C.3070102@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h
index 7c1aebf..0c90dd9 100644
--- a/arch/x86/include/asm/mpspec.h
+++ b/arch/x86/include/asm/mpspec.h
@@ -5,6 +5,7 @@
#include <asm/mpspec_def.h>
#include <asm/x86_init.h>
+#include <asm/apicdef.h>
extern int apic_version[];
extern int pic_mode;
@@ -107,7 +108,7 @@
int active_high_low);
#endif /* CONFIG_ACPI */
-#define PHYSID_ARRAY_SIZE BITS_TO_LONGS(MAX_APICS)
+#define PHYSID_ARRAY_SIZE BITS_TO_LONGS(MAX_LOCAL_APIC)
struct physid_mask {
unsigned long mask[PHYSID_ARRAY_SIZE];
@@ -122,31 +123,31 @@
test_and_set_bit(physid, (map).mask)
#define physids_and(dst, src1, src2) \
- bitmap_and((dst).mask, (src1).mask, (src2).mask, MAX_APICS)
+ bitmap_and((dst).mask, (src1).mask, (src2).mask, MAX_LOCAL_APIC)
#define physids_or(dst, src1, src2) \
- bitmap_or((dst).mask, (src1).mask, (src2).mask, MAX_APICS)
+ bitmap_or((dst).mask, (src1).mask, (src2).mask, MAX_LOCAL_APIC)
#define physids_clear(map) \
- bitmap_zero((map).mask, MAX_APICS)
+ bitmap_zero((map).mask, MAX_LOCAL_APIC)
#define physids_complement(dst, src) \
- bitmap_complement((dst).mask, (src).mask, MAX_APICS)
+ bitmap_complement((dst).mask, (src).mask, MAX_LOCAL_APIC)
#define physids_empty(map) \
- bitmap_empty((map).mask, MAX_APICS)
+ bitmap_empty((map).mask, MAX_LOCAL_APIC)
#define physids_equal(map1, map2) \
- bitmap_equal((map1).mask, (map2).mask, MAX_APICS)
+ bitmap_equal((map1).mask, (map2).mask, MAX_LOCAL_APIC)
#define physids_weight(map) \
- bitmap_weight((map).mask, MAX_APICS)
+ bitmap_weight((map).mask, MAX_LOCAL_APIC)
#define physids_shift_right(d, s, n) \
- bitmap_shift_right((d).mask, (s).mask, n, MAX_APICS)
+ bitmap_shift_right((d).mask, (s).mask, n, MAX_LOCAL_APIC)
#define physids_shift_left(d, s, n) \
- bitmap_shift_left((d).mask, (s).mask, n, MAX_APICS)
+ bitmap_shift_left((d).mask, (s).mask, n, MAX_LOCAL_APIC)
static inline unsigned long physids_coerce(physid_mask_t *map)
{
@@ -159,14 +160,6 @@
map->mask[0] = physids;
}
-/* Note: will create very large stack frames if physid_mask_t is big */
-#define physid_mask_of_physid(physid) \
- ({ \
- physid_mask_t __physid_mask = PHYSID_MASK_NONE; \
- physid_set(physid, __physid_mask); \
- __physid_mask; \
- })
-
static inline void physid_set_mask_of_physid(int physid, physid_mask_t *map)
{
physids_clear(*map);
diff --git a/arch/x86/include/asm/mpspec_def.h b/arch/x86/include/asm/mpspec_def.h
index 4a7f96d..c0a955a 100644
--- a/arch/x86/include/asm/mpspec_def.h
+++ b/arch/x86/include/asm/mpspec_def.h
@@ -15,13 +15,6 @@
#ifdef CONFIG_X86_32
# define MAX_MPC_ENTRY 1024
-# define MAX_APICS 256
-#else
-# if NR_CPUS <= 255
-# define MAX_APICS 255
-# else
-# define MAX_APICS 32768
-# endif
#endif
/* Intel MP Floating Pointer Structure */