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percpu: more flexibility for @dyn_size of pcpu_setup_first_chunk() 

Impact: cleanup, more flexibility for first chunk init

Non-negative @dyn_size used to be allowed iff @unit_size wasn't auto.
This restriction stemmed from implementation detail and made things a
bit less intuitive.  This patch allows @dyn_size to be specified
regardless of @unit_size and swaps the positions of @dyn_size and
@unit_size so that the parameter order makes more sense (static,
reserved and dyn sizes followed by enclosing unit_size).

While at it, add @unit_size >= PCPU_MIN_UNIT_SIZE sanity check.

Signed-off-by: Tejun Heo <tj@kernel.org>
hifive-unleashed-5.1
Tejun Heo 2009-03-10 16:27:48 +09:00
parent e01009833e
commit 6074d5b0a3
3 changed files with 21 additions and 22 deletions
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13
arch/x86/kernel/setup_percpu.c
View File

@ -233,8 +233,8 @@ proceed:
"%zu bytes\n", vm.addr, static_size);
ret = pcpu_setup_first_chunk(pcpur_get_page, static_size,
PERCPU_FIRST_CHUNK_RESERVE,
PMD_SIZE, dyn_size, vm.addr, NULL);
PERCPU_FIRST_CHUNK_RESERVE, dyn_size,
PMD_SIZE, vm.addr, NULL);
goto out_free_ar;
enomem:
@ -315,9 +315,8 @@ static ssize_t __init setup_pcpu_embed(size_t static_size)
pcpue_size >> PAGE_SHIFT, pcpue_ptr, static_size);
return pcpu_setup_first_chunk(pcpue_get_page, static_size,
PERCPU_FIRST_CHUNK_RESERVE,
pcpue_unit_size, dyn_size,
pcpue_ptr, NULL);
PERCPU_FIRST_CHUNK_RESERVE, dyn_size,
pcpue_unit_size, pcpue_ptr, NULL);
}
/*
@ -375,8 +374,8 @@ static ssize_t __init setup_pcpu_4k(size_t static_size)
pcpu4k_nr_static_pages, static_size);
ret = pcpu_setup_first_chunk(pcpu4k_get_page, static_size,
PERCPU_FIRST_CHUNK_RESERVE, -1, -1, NULL,
pcpu4k_populate_pte);
PERCPU_FIRST_CHUNK_RESERVE, -1,
-1, NULL, pcpu4k_populate_pte);
goto out_free_ar;
enomem:

2
include/linux/percpu.h
View File

@ -107,7 +107,7 @@ typedef void (*pcpu_populate_pte_fn_t)(unsigned long addr);
extern size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
size_t static_size, size_t reserved_size,
ssize_t unit_size, ssize_t dyn_size,
ssize_t dyn_size, ssize_t unit_size,
void *base_addr,
pcpu_populate_pte_fn_t populate_pte_fn);

28
mm/percpu.c
View File

@ -1027,8 +1027,8 @@ EXPORT_SYMBOL_GPL(free_percpu);
* @get_page_fn: callback to fetch page pointer
* @static_size: the size of static percpu area in bytes
* @reserved_size: the size of reserved percpu area in bytes
* @unit_size: unit size in bytes, must be multiple of PAGE_SIZE, -1 for auto
* @dyn_size: free size for dynamic allocation in bytes, -1 for auto
* @unit_size: unit size in bytes, must be multiple of PAGE_SIZE, -1 for auto
* @base_addr: mapped address, NULL for auto
* @populate_pte_fn: callback to allocate pagetable, NULL if unnecessary
*
@ -1053,14 +1053,14 @@ EXPORT_SYMBOL_GPL(free_percpu);
* limited offset range for symbol relocations to guarantee module
* percpu symbols fall inside the relocatable range.
*
* @dyn_size, if non-negative, determines the number of bytes
* available for dynamic allocation in the first chunk. Specifying
* non-negative value makes percpu leave alone the area beyond
* @static_size + @reserved_size + @dyn_size.
*
* @unit_size, if non-negative, specifies unit size and must be
* aligned to PAGE_SIZE and equal to or larger than @static_size +
* @reserved_size + @dyn_size.
*
* @dyn_size, if non-negative, limits the number of bytes available
* for dynamic allocation in the first chunk. Specifying non-negative
* value make percpu leave alone the area beyond @static_size +
* @reserved_size + @dyn_size.
* @reserved_size + if non-negative, @dyn_size.
*
* Non-null @base_addr means that the caller already allocated virtual
* region for the first chunk and mapped it. percpu must not mess
@ -1083,12 +1083,14 @@ EXPORT_SYMBOL_GPL(free_percpu);
*/
size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
size_t static_size, size_t reserved_size,
ssize_t unit_size, ssize_t dyn_size,
ssize_t dyn_size, ssize_t unit_size,
void *base_addr,
pcpu_populate_pte_fn_t populate_pte_fn)
{
static struct vm_struct first_vm;
static int smap[2], dmap[2];
size_t size_sum = static_size + reserved_size +
(dyn_size >= 0 ? dyn_size : 0);
struct pcpu_chunk *schunk, *dchunk = NULL;
unsigned int cpu;
int nr_pages;
@ -1099,20 +1101,18 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn,
ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC);
BUG_ON(!static_size);
if (unit_size >= 0) {
BUG_ON(unit_size < static_size + reserved_size +
(dyn_size >= 0 ? dyn_size : 0));
BUG_ON(unit_size < size_sum);
BUG_ON(unit_size & ~PAGE_MASK);
} else {
BUG_ON(dyn_size >= 0);
BUG_ON(unit_size < PCPU_MIN_UNIT_SIZE);
} else
BUG_ON(base_addr);
}
BUG_ON(base_addr && populate_pte_fn);
if (unit_size >= 0)
pcpu_unit_pages = unit_size >> PAGE_SHIFT;
else
pcpu_unit_pages = max_t(int, PCPU_MIN_UNIT_SIZE >> PAGE_SHIFT,
PFN_UP(static_size + reserved_size));
PFN_UP(size_sum));
pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT;
pcpu_chunk_size = num_possible_cpus() * pcpu_unit_size;