static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size)
{
int page_start = PFN_DOWN(off);
int page_end = PFN_UP(off + size);
struct page **pages;
unsigned long *populated;
int rs, re;
rs = page_start;
pcpu_next_unpop(chunk, &rs, &re, page_end);
if (rs == page_start && re == page_end)
return;
WARN_ON(chunk->immutable);
pages = pcpu_get_pages_and_bitmap(chunk, &populated, false);
BUG_ON(!pages);
pcpu_pre_unmap_flush(chunk, page_start, page_end);
pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end)
pcpu_unmap_pages(chunk, pages, populated, rs, re);
pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end)
pcpu_free_pages(chunk, pages, populated, rs, re);
bitmap_copy(chunk->populated, populated, pcpu_unit_pages);
}
/**
* pcpu_alloc_pages - allocates pages for @chunk
* @chunk: target chunk
* @pages: array to put the allocated pages into, indexed by pcpu_page_idx()
* @populated: populated bitmap
* @page_start: page index of the first page to be allocated
* @page_end: page index of the last page to be allocated + 1
*
* Allocate pages [@page_start,@page_end) into @pages for all units.
* The allocation is for @chunk. Percpu core doesn't care about the
* content of @pages and will pass it verbatim to pcpu_map_pages().
*/
static int pcpu_alloc_pages(struct pcpu_chunk *chunk,
struct page **pages, unsigned long *populated,
int page_start, int page_end)
{
const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD;
unsigned int cpu;
int nid;
int i;
for_each_possible_cpu(cpu) {
for (i = page_start; i < page_end; i++) {
struct page **pagep = &pages[pcpu_page_idx(cpu, i)];
//*pagep = alloc_pages_node(cpu_to_node(cpu), gfp, 0);
nid = cpu_to_node(cpu);
if((nid == -1) || !(node_zonelist(nid, GFP_KERNEL)->_zonerefs->zone))
nid = numa_node_id();
*pagep = alloc_pages_node(nid, gfp, 0);
if (!*pagep) {
pcpu_free_pages(chunk, pages, populated,
page_start, page_end);
return -ENOMEM;
}
}
}
return 0;
}
/*! 2016-04-02 study -ing */
static int pcpu_alloc_pages(struct pcpu_chunk *chunk,
struct page **pages, unsigned long *populated,
int page_start, int page_end)
{
const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD;
unsigned int cpu;
int i;
for_each_possible_cpu(cpu) {
for (i = page_start; i < page_end; i++) {
/*! pages에서 pcpu page 의 index에 해당하는 위치를 찾는다.
* (pages 는 포인터 배열)
*/
struct page **pagep = &pages[pcpu_page_idx(cpu, i)];
/*! 해당 위치에 pages node alloc */
*pagep = alloc_pages_node(cpu_to_node(cpu), gfp, 0);
if (!*pagep) {
/*! alloc 실패 시 free */
pcpu_free_pages(chunk, pages, populated,
page_start, page_end);
return -ENOMEM;
}
}
}
return 0;
}
/**
* pcpu_populate_chunk - populate and map an area of a pcpu_chunk
* @chunk: chunk of interest
* @page_start: the start page
* @page_end: the end page
*
* For each cpu, populate and map pages [@page_start,@page_end) into
* @chunk.
*
* CONTEXT:
* pcpu_alloc_mutex, does GFP_KERNEL allocation.
*/
static int pcpu_populate_chunk(struct pcpu_chunk *chunk,
int page_start, int page_end)
{
struct page **pages;
pages = pcpu_get_pages();
if (!pages)
return -ENOMEM;
if (pcpu_alloc_pages(chunk, pages, page_start, page_end))
return -ENOMEM;
if (pcpu_map_pages(chunk, pages, page_start, page_end)) {
pcpu_free_pages(chunk, pages, page_start, page_end);
return -ENOMEM;
}
pcpu_post_map_flush(chunk, page_start, page_end);
return 0;
}
/**
* pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk
* @chunk: chunk to depopulate
* @page_start: the start page
* @page_end: the end page
*
* For each cpu, depopulate and unmap pages [@page_start,@page_end)
* from @chunk.
*
* CONTEXT:
* pcpu_alloc_mutex.
*/
static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk,
int page_start, int page_end)
{
struct page **pages;
/*
* If control reaches here, there must have been at least one
* successful population attempt so the temp pages array must
* be available now.
*/
pages = pcpu_get_pages();
BUG_ON(!pages);
/* unmap and free */
pcpu_pre_unmap_flush(chunk, page_start, page_end);
pcpu_unmap_pages(chunk, pages, page_start, page_end);
/* no need to flush tlb, vmalloc will handle it lazily */
pcpu_free_pages(chunk, pages, page_start, page_end);
}
static int pcpu_alloc_pages(struct pcpu_chunk *chunk,
struct page **pages, unsigned long *populated,
int page_start, int page_end)
{
const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD;
unsigned int cpu;
int i;
for_each_possible_cpu(cpu) {
for (i = page_start; i < page_end; i++) {
struct page **pagep = &pages[pcpu_page_idx(cpu, i)];
*pagep = alloc_pages_node(cpu_to_node(cpu), gfp, 0);
if (!*pagep) {
pcpu_free_pages(chunk, pages, populated,
page_start, page_end);
return -ENOMEM;
}
}
}
return 0;
}
/**
* pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk
* @chunk: chunk to depopulate
* @off: offset to the area to depopulate
* @size: size of the area to depopulate in bytes
* @flush: whether to flush cache and tlb or not
*
* For each cpu, depopulate and unmap pages [@page_start,@page_end)
* from @chunk. If @flush is true, vcache is flushed before unmapping
* and tlb after.
*
* CONTEXT:
* pcpu_alloc_mutex.
*/
static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size)
{
int page_start = PFN_DOWN(off);
int page_end = PFN_UP(off + size);
struct page **pages;
unsigned long *populated;
int rs, re;
/* quick path, check whether it's empty already */
rs = page_start;
pcpu_next_unpop(chunk, &rs, &re, page_end);
if (rs == page_start && re == page_end)
return;
/* immutable chunks can't be depopulated */
WARN_ON(chunk->immutable);
/*
* If control reaches here, there must have been at least one
* successful population attempt so the temp pages array must
* be available now.
*/
pages = pcpu_get_pages_and_bitmap(chunk, &populated, false);
BUG_ON(!pages);
/* unmap and free */
pcpu_pre_unmap_flush(chunk, page_start, page_end);
pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end)
pcpu_unmap_pages(chunk, pages, populated, rs, re);
/* no need to flush tlb, vmalloc will handle it lazily */
pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end)
pcpu_free_pages(chunk, pages, populated, rs, re);
/* commit new bitmap */
bitmap_copy(chunk->populated, populated, pcpu_unit_pages);
}