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Commit c8a51be4 authored by Tejun Heo's avatar Tejun Heo
Browse files

percpu: reorder a few functions in mm/percpu.c 



(de)populate functions are about to be reimplemented to drop
pcpu_chunk->page array.  Move a few functions so that the rewrite
patch doesn't have code movement making it more difficult to read.

[ Impact: code movement ]

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
parent 38a6be52

mm/percpu.c

+45 −45
Original line number Diff line number Diff line
@@ -181,17 +181,17 @@ static int pcpu_page_idx(unsigned int cpu, int page_idx) 
	return cpu * pcpu_unit_pages + page_idx;

}



static struct page **pcpu_chunk_pagep(struct pcpu_chunk *chunk,

static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk,

				     unsigned int cpu, int page_idx)

{

	return &chunk->page[pcpu_page_idx(cpu, page_idx)];

	return (unsigned long)chunk->vm->addr +

		(pcpu_page_idx(cpu, page_idx) << PAGE_SHIFT);

}



static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk,

static struct page **pcpu_chunk_pagep(struct pcpu_chunk *chunk,

				      unsigned int cpu, int page_idx)

{

	return (unsigned long)chunk->vm->addr +

		(pcpu_page_idx(cpu, page_idx) << PAGE_SHIFT);

	return &chunk->page[pcpu_page_idx(cpu, page_idx)];

}



static bool pcpu_chunk_page_occupied(struct pcpu_chunk *chunk,
@@ -583,6 +583,45 @@ static void pcpu_unmap(struct pcpu_chunk *chunk, int page_start, int page_end, 
				       pcpu_chunk_addr(chunk, last, page_end));

}



static int __pcpu_map_pages(unsigned long addr, struct page **pages,

			    int nr_pages)

{

	return map_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT,

					PAGE_KERNEL, pages);

}



/**

 * pcpu_map - map pages into a pcpu_chunk

 * @chunk: chunk of interest

 * @page_start: page index of the first page to map

 * @page_end: page index of the last page to map + 1

 *

 * For each cpu, map pages [@page_start,@page_end) into @chunk.

 * vcache is flushed afterwards.

 */

static int pcpu_map(struct pcpu_chunk *chunk, int page_start, int page_end)

{

	unsigned int last = num_possible_cpus() - 1;

	unsigned int cpu;

	int err;



	/* map must not be done on immutable chunk */

	WARN_ON(chunk->immutable);



	for_each_possible_cpu(cpu) {

		err = __pcpu_map_pages(pcpu_chunk_addr(chunk, cpu, page_start),

				       pcpu_chunk_pagep(chunk, cpu, page_start),

				       page_end - page_start);

		if (err < 0)

			return err;

	}



	/* flush at once, please read comments in pcpu_unmap() */

	flush_cache_vmap(pcpu_chunk_addr(chunk, 0, page_start),

			 pcpu_chunk_addr(chunk, last, page_end));

	return 0;

}



/**

 * pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk

 * @chunk: chunk to depopulate
@@ -632,45 +671,6 @@ static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size, 
		pcpu_unmap(chunk, unmap_start, unmap_end, flush);

}



static int __pcpu_map_pages(unsigned long addr, struct page **pages,

			    int nr_pages)

{

	return map_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT,

					PAGE_KERNEL, pages);

}



/**

 * pcpu_map - map pages into a pcpu_chunk

 * @chunk: chunk of interest

 * @page_start: page index of the first page to map

 * @page_end: page index of the last page to map + 1

 *

 * For each cpu, map pages [@page_start,@page_end) into @chunk.

 * vcache is flushed afterwards.

 */

static int pcpu_map(struct pcpu_chunk *chunk, int page_start, int page_end)

{

	unsigned int last = num_possible_cpus() - 1;

	unsigned int cpu;

	int err;



	/* map must not be done on immutable chunk */

	WARN_ON(chunk->immutable);



	for_each_possible_cpu(cpu) {

		err = __pcpu_map_pages(pcpu_chunk_addr(chunk, cpu, page_start),

				       pcpu_chunk_pagep(chunk, cpu, page_start),

				       page_end - page_start);

		if (err < 0)

			return err;

	}



	/* flush at once, please read comments in pcpu_unmap() */

	flush_cache_vmap(pcpu_chunk_addr(chunk, 0, page_start),

			 pcpu_chunk_addr(chunk, last, page_end));

	return 0;

}



/**

 * pcpu_populate_chunk - populate and map an area of a pcpu_chunk

 * @chunk: chunk of interest