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| author |   Chang S. Bae <chang.seok.bae@intel.com> | 2018-09-18 16:08:57 -0700 |
|---|---|---|
| committer |   Ingo Molnar <mingo@kernel.org> | 2018-10-08 10:41:10 +0200 |
| commit | c4755613a1339ea77dbb15de75c9f74217209265 (patch) | |
| tree | fc7b090af6ae081c5c6faec8d175a246581fa130 | |
| parent | x86/fsgsbase/64: Factor out FS/GS segment loading from __switch_to() (diff) | |
| download | linux-dev-c4755613a1339ea77dbb15de75c9f74217209265.tar.xz linux-dev-c4755613a1339ea77dbb15de75c9f74217209265.zip | |
x86/segments/64: Rename the GDT PER_CPU entry to CPU_NUMBER
The old 'per CPU' naming was misleading: 64-bit kernels don't use this
GDT entry for per CPU data, but to store the CPU (and node) ID.
[ mingo: Wrote new changelog. ]
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Markus T Metzger <markus.t.metzger@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Link: http://lkml.kernel.org/r/1537312139-5580-7-git-send-email-chang.seok.bae@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
| -rw-r--r-- | arch/x86/entry/vdso/vma.c | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/segment.h | 5 | ||||
| -rw-r--r-- | arch/x86/include/asm/vgtod.h | 8 |
3 files changed, 7 insertions, 8 deletions
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 5b8b556dbb12..0b114aafcedc 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -359,7 +359,7 @@ static void vgetcpu_cpu_init(void *arg) d.p = 1; /* Present */ d.d = 1; /* 32-bit */ - write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_PER_CPU, &d, DESCTYPE_S); + write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_CPU_NUMBER, &d, DESCTYPE_S); } static int vgetcpu_online(unsigned int cpu) diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h index e293c122d0d5..e3e788ea52e5 100644 --- a/arch/x86/include/asm/segment.h +++ b/arch/x86/include/asm/segment.h @@ -186,8 +186,7 @@ #define GDT_ENTRY_TLS_MIN 12 #define GDT_ENTRY_TLS_MAX 14 -/* Abused to load per CPU data from limit */ -#define GDT_ENTRY_PER_CPU 15 +#define GDT_ENTRY_CPU_NUMBER 15 /* * Number of entries in the GDT table: @@ -207,7 +206,7 @@ #define __USER_DS (GDT_ENTRY_DEFAULT_USER_DS*8 + 3) #define __USER32_DS __USER_DS #define __USER_CS (GDT_ENTRY_DEFAULT_USER_CS*8 + 3) -#define __PER_CPU_SEG (GDT_ENTRY_PER_CPU*8 + 3) +#define __CPU_NUMBER_SEG (GDT_ENTRY_CPU_NUMBER*8 + 3) #endif diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h index 53748541c487..4e81ea920722 100644 --- a/arch/x86/include/asm/vgtod.h +++ b/arch/x86/include/asm/vgtod.h @@ -86,9 +86,9 @@ static inline unsigned int __getcpu(void) unsigned int p; /* - * Load per CPU data from GDT. LSL is faster than RDTSCP and - * works on all CPUs. This is volatile so that it orders - * correctly wrt barrier() and to keep gcc from cleverly + * Load CPU (and node) number from GDT. LSL is faster than RDTSCP + * and works on all CPUs. This is volatile so that it orders + * correctly with respect to barrier() and to keep GCC from cleverly * hoisting it out of the calling function. * * If RDPID is available, use it. @@ -96,7 +96,7 @@ static inline unsigned int __getcpu(void) alternative_io ("lsl %[seg],%[p]", ".byte 0xf3,0x0f,0xc7,0xf8", /* RDPID %eax/rax */ X86_FEATURE_RDPID, - [p] "=a" (p), [seg] "r" (__PER_CPU_SEG)); + [p] "=a" (p), [seg] "r" (__CPU_NUMBER_SEG)); return p; } |