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x86/asm/entry: Remove INIT_TSS and fold the definitions into 'cpu_tss' 

The INIT_TSS is unnecessary.  Just define the initial TSS where
'cpu_tss' is defined.

While we're at it, merge the 32-bit and 64-bit definitions.  The
only syntactic change is that 32-bit kernels were computing sp0
as long, but now they compute it as unsigned long.

Verified by objdump: the contents and relocations of
.data..percpu..shared_aligned are unchanged on 32-bit and 64-bit
kernels.

Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/8fc39fa3f6c5d635e93afbdd1a0fe0678a6d7913.1425611534.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Andy Lutomirski 2015-03-05 19:19:06 -08:00 committed by Ingo Molnar
parent 24933b82c0
commit d0a0de21f8
2 changed files with 19 additions and 21 deletions
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20
arch/x86/include/asm/processor.h
View File

@ -818,22 +818,6 @@ static inline void spin_lock_prefetch(const void *x)
.io_bitmap_ptr = NULL, \
}
/*
* Note that the .io_bitmap member must be extra-big. This is because
* the CPU will access an additional byte beyond the end of the IO
* permission bitmap. The extra byte must be all 1 bits, and must
* be within the limit.
*/
#define INIT_TSS { \
.x86_tss = { \
.sp0 = sizeof(init_stack) + (long)&init_stack, \
.ss0 = __KERNEL_DS, \
.ss1 = __KERNEL_CS, \
.io_bitmap_base = INVALID_IO_BITMAP_OFFSET, \
}, \
.io_bitmap = { [0 ... IO_BITMAP_LONGS] = ~0 }, \
}
extern unsigned long thread_saved_pc(struct task_struct *tsk);
#define THREAD_SIZE_LONGS (THREAD_SIZE/sizeof(unsigned long))
@ -892,10 +876,6 @@ extern unsigned long thread_saved_pc(struct task_struct *tsk);
.sp0 = (unsigned long)&init_stack + sizeof(init_stack) \
}
#define INIT_TSS { \
.x86_tss.sp0 = (unsigned long)&init_stack + sizeof(init_stack) \
}
/*
* Return saved PC of a blocked thread.
* What is this good for? it will be always the scheduler or ret_from_fork.

20
arch/x86/kernel/process.c
View File

@ -37,7 +37,25 @@
* section. Since TSS's are completely CPU-local, we want them
* on exact cacheline boundaries, to eliminate cacheline ping-pong.
*/
__visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = INIT_TSS;
__visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = {
.x86_tss = {
.sp0 = (unsigned long)&init_stack + sizeof(init_stack),
#ifdef CONFIG_X86_32
.ss0 = __KERNEL_DS,
.ss1 = __KERNEL_CS,
.io_bitmap_base = INVALID_IO_BITMAP_OFFSET,
#endif
},
#ifdef CONFIG_X86_32
/*
* Note that the .io_bitmap member must be extra-big. This is because
* the CPU will access an additional byte beyond the end of the IO
* permission bitmap. The extra byte must be all 1 bits, and must
* be within the limit.
*/
.io_bitmap = { [0 ... IO_BITMAP_LONGS] = ~0 },
#endif
};
EXPORT_PER_CPU_SYMBOL_GPL(cpu_tss);
#ifdef CONFIG_X86_64