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Commit c8f3329a authored by Tejun Heo's avatar Tejun Heo Committed by Ingo Molnar
Browse files

x86: use static _cpu_pda array 



_cpu_pda array first uses statically allocated storage in data.init
and then switches to allocated bootmem to conserve space.  However,
after folding pda area into percpu area, _cpu_pda array will be
removed completely.  Drop the reallocation part to simplify the code
for soon-to-follow changes.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent f32ff538

arch/x86/include/asm/pda.h

+2 −1
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <linux/stddef.h>

#include <linux/types.h>

#include <linux/cache.h>

#include <linux/threads.h>

#include <asm/page.h>



/* Per processor datastructure. %gs points to it while the kernel runs */
@@ -39,7 +40,7 @@ struct x8664_pda { 
	unsigned irq_spurious_count;

} ____cacheline_aligned_in_smp;



extern struct x8664_pda **_cpu_pda;

extern struct x8664_pda *_cpu_pda[NR_CPUS];

extern void pda_init(int);



#define cpu_pda(i) (_cpu_pda[i])

arch/x86/kernel/cpu/common.c

+1 −1
Original line number Diff line number Diff line
@@ -879,7 +879,7 @@ static __init int setup_disablecpuid(char *arg) 
__setup("clearcpuid=", setup_disablecpuid);



#ifdef CONFIG_X86_64

struct x8664_pda **_cpu_pda __read_mostly;

struct x8664_pda *_cpu_pda[NR_CPUS] __read_mostly;

EXPORT_SYMBOL(_cpu_pda);



struct desc_ptr idt_descr = { 256 * 16 - 1, (unsigned long) idt_table };

arch/x86/kernel/head64.c

+0 −12
Original line number Diff line number Diff line
@@ -29,20 +29,8 @@ 
/* boot cpu pda, referenced by head_64.S to initialize %gs for boot CPU */

struct x8664_pda _boot_cpu_pda;



#ifdef CONFIG_SMP

/*

 * We install an empty cpu_pda pointer table to indicate to early users

 * (numa_set_node) that the cpu_pda pointer table for cpus other than

 * the boot cpu is not yet setup.

 */

static struct x8664_pda *__cpu_pda[NR_CPUS] __initdata;

#else

static struct x8664_pda *__cpu_pda[NR_CPUS] __read_mostly;

#endif



void __init x86_64_init_pda(void)

{

	_cpu_pda = __cpu_pda;

	cpu_pda(0) = &_boot_cpu_pda;

	cpu_pda(0)->data_offset =

		(unsigned long)(__per_cpu_load - __per_cpu_start);

arch/x86/kernel/setup_percpu.c

+3 −11
Original line number Diff line number Diff line
@@ -114,7 +114,6 @@ static inline void setup_cpu_pda_map(void) { } 
static void __init setup_cpu_pda_map(void)

{

	char *pda;

	struct x8664_pda **new_cpu_pda;

	unsigned long size;

	int cpu;
@@ -122,28 +121,21 @@ static void __init setup_cpu_pda_map(void) 


	/* allocate cpu_pda array and pointer table */

	{

		unsigned long tsize = nr_cpu_ids * sizeof(void *);

		unsigned long asize = size * (nr_cpu_ids - 1);



		tsize = roundup(tsize, cache_line_size());

		new_cpu_pda = alloc_bootmem(tsize + asize);

		pda = (char *)new_cpu_pda + tsize;

		pda = alloc_bootmem(asize);

	}



	/* initialize pointer table to static pda's */

	for_each_possible_cpu(cpu) {

		if (cpu == 0) {

			/* leave boot cpu pda in place */

			new_cpu_pda[0] = cpu_pda(0);

			continue;

		}

		new_cpu_pda[cpu] = (struct x8664_pda *)pda;

		new_cpu_pda[cpu]->in_bootmem = 1;

		cpu_pda(cpu) = (struct x8664_pda *)pda;

		cpu_pda(cpu)->in_bootmem = 1;

		pda += size;

	}



	/* point to new pointer table */

	_cpu_pda = new_cpu_pda;

}



#endif /* CONFIG_SMP && CONFIG_X86_64 */