From cb2ded37fd2e1039f96c8c892da024a8f033add5 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Tue, 4 Jan 2011 16:38:52 -0800 Subject: 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 Cc: H. Peter Anvin Cc: "Eric W. Biederman" LKML-Reference: <4D23BD9C.3070102@kernel.org> Signed-off-by: Ingo Molnar --- arch/x86/include/asm/mpspec.h | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-) (limited to 'arch/x86/include/asm/mpspec.h') diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h index 7c1aebf8fcbf..0c90dd9f0505 100644 --- a/arch/x86/include/asm/mpspec.h +++ b/arch/x86/include/asm/mpspec.h @@ -5,6 +5,7 @@ #include #include +#include extern int apic_version[]; extern int pic_mode; @@ -107,7 +108,7 @@ extern int mp_register_gsi(struct device *dev, u32 gsi, int edge_level, 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 @@ typedef struct physid_mask physid_mask_t; 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 @@ static inline void physids_promote(unsigned long physids, physid_mask_t *map) 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); -- cgit v1.2.3