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Commit b154ff05 authored by Nitin Gupta's avatar Nitin Gupta Committed by Greg Kroah-Hartman
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staging: zram: remove xvmalloc 

Removes the xvmalloc allocator code from the zram driver
Signed-off-by: default avatarNitin Gupta <ngupta@vflare.org>
Acked-by: default avatarSeth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fd1a30de
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drivers/staging/Makefile
View file @ b154ff05
......@@ -35,7 +35,6 @@ obj-$(CONFIG_VME_BUS) += vme/
obj-$(CONFIG_DX_SEP) += sep/
obj-$(CONFIG_IIO) += iio/
obj-$(CONFIG_ZRAM) += zram/
obj-$(CONFIG_XVMALLOC) += zram/
obj-$(CONFIG_ZCACHE) += zcache/
obj-$(CONFIG_ZSMALLOC) += zsmalloc/
obj-$(CONFIG_WLAGS49_H2) += wlags49_h2/
......
drivers/staging/zram/xvmalloc.c deleted 100644 → 0
View file @ fd1a30de
/*
* xvmalloc memory allocator
*
* Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
*
* Released under the terms of 3-clause BSD License
* Released under the terms of GNU General Public License Version 2.0
*/
#ifdef CONFIG_ZRAM_DEBUG
#define DEBUG
#endif
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/highmem.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/slab.h>
#include "xvmalloc.h"
#include "xvmalloc_int.h"
static void stat_inc(u64 *value)
{
*value = *value + 1;
}
static void stat_dec(u64 *value)
{
*value = *value - 1;
}
static int test_flag(struct block_header *block, enum blockflags flag)
{
return block->prev & BIT(flag);
}
static void set_flag(struct block_header *block, enum blockflags flag)
{
block->prev |= BIT(flag);
}
static void clear_flag(struct block_header *block, enum blockflags flag)
{
block->prev &= ~BIT(flag);
}
/*
* Given <page, offset> pair, provide a dereferencable pointer.
* This is called from xv_malloc/xv_free path, so it
* needs to be fast.
*/
static void *get_ptr_atomic(struct page *page, u16 offset, enum km_type type)
{
unsigned char *base;
base = kmap_atomic(page, type);
return base + offset;
}
static void put_ptr_atomic(void *ptr, enum km_type type)
{
kunmap_atomic(ptr, type);
}
static u32 get_blockprev(struct block_header *block)
{
return block->prev & PREV_MASK;
}
static void set_blockprev(struct block_header *block, u16 new_offset)
{
block->prev = new_offset | (block->prev & FLAGS_MASK);
}
static struct block_header *BLOCK_NEXT(struct block_header *block)
{
return (struct block_header *)
((char *)block + block->size + XV_ALIGN);
}
/*
* Get index of free list containing blocks of maximum size
* which is less than or equal to given size.
*/
static u32 get_index_for_insert(u32 size)
{
if (unlikely(size > XV_MAX_ALLOC_SIZE))
size = XV_MAX_ALLOC_SIZE;
size &= ~FL_DELTA_MASK;
return (size - XV_MIN_ALLOC_SIZE) >> FL_DELTA_SHIFT;
}
/*
* Get index of free list having blocks of size greater than
* or equal to requested size.
*/
static u32 get_index(u32 size)
{
if (unlikely(size < XV_MIN_ALLOC_SIZE))
size = XV_MIN_ALLOC_SIZE;
size = ALIGN(size, FL_DELTA);
return (size - XV_MIN_ALLOC_SIZE) >> FL_DELTA_SHIFT;
}
/**
* find_block - find block of at least given size
* @pool: memory pool to search from
* @size: size of block required
* @page: page containing required block
* @offset: offset within the page where block is located.
*
* Searches two level bitmap to locate block of at least
* the given size. If such a block is found, it provides
* <page, offset> to identify this block and returns index
* in freelist where we found this block.
* Otherwise, returns 0 and <page, offset> params are not touched.
*/
static u32 find_block(struct xv_pool *pool, u32 size,
struct page **page, u32 *offset)
{
ulong flbitmap, slbitmap;
u32 flindex, slindex, slbitstart;
/* There are no free blocks in this pool */
if (!pool->flbitmap)
return 0;
/* Get freelist index correspoding to this size */
slindex = get_index(size);
slbitmap = pool->slbitmap[slindex / BITS_PER_LONG];
slbitstart = slindex % BITS_PER_LONG;
/*
* If freelist is not empty at this index, we found the
* block - head of this list. This is approximate best-fit match.
*/
if (test_bit(slbitstart, &slbitmap)) {
*page = pool->freelist[slindex].page;
*offset = pool->freelist[slindex].offset;
return slindex;
}
/*
* No best-fit found. Search a bit further in bitmap for a free block.
* Second level bitmap consists of series of 32-bit chunks. Search
* further in the chunk where we expected a best-fit, starting from
* index location found above.
*/
slbitstart++;
slbitmap >>= slbitstart;
/* Skip this search if we were already at end of this bitmap chunk */
if ((slbitstart != BITS_PER_LONG) && slbitmap) {
slindex += __ffs(slbitmap) + 1;
*page = pool->freelist[slindex].page;
*offset = pool->freelist[slindex].offset;
return slindex;
}
/* Now do a full two-level bitmap search to find next nearest fit */
flindex = slindex / BITS_PER_LONG;
flbitmap = (pool->flbitmap) >> (flindex + 1);
if (!flbitmap)
return 0;
flindex += __ffs(flbitmap) + 1;
slbitmap = pool->slbitmap[flindex];
slindex = (flindex * BITS_PER_LONG) + __ffs(slbitmap);
*page = pool->freelist[slindex].page;
*offset = pool->freelist[slindex].offset;
return slindex;
}
/*
* Insert block at <page, offset> in freelist of given pool.
* freelist used depends on block size.
*/
static void insert_block(struct xv_pool *pool, struct page *page, u32 offset,
struct block_header *block)
{
u32 flindex, slindex;
struct block_header *nextblock;
slindex = get_index_for_insert(block->size);
flindex = slindex / BITS_PER_LONG;
block->link.prev_page = NULL;
block->link.prev_offset = 0;
block->link.next_page = pool->freelist[slindex].page;
block->link.next_offset = pool->freelist[slindex].offset;
pool->freelist[slindex].page = page;
pool->freelist[slindex].offset = offset;
if (block->link.next_page) {
nextblock = get_ptr_atomic(block->link.next_page,
block->link.next_offset, KM_USER1);
nextblock->link.prev_page = page;
nextblock->link.prev_offset = offset;
put_ptr_atomic(nextblock, KM_USER1);
/* If there was a next page then the free bits are set. */
return;
}
__set_bit(slindex % BITS_PER_LONG, &pool->slbitmap[flindex]);
__set_bit(flindex, &pool->flbitmap);
}
/*
* Remove block from freelist. Index 'slindex' identifies the freelist.
*/
static void remove_block(struct xv_pool *pool, struct page *page, u32 offset,
struct block_header *block, u32 slindex)
{
u32 flindex = slindex / BITS_PER_LONG;
struct block_header *tmpblock;
if (block->link.prev_page) {
tmpblock = get_ptr_atomic(block->link.prev_page,
block->link.prev_offset, KM_USER1);
tmpblock->link.next_page = block->link.next_page;
tmpblock->link.next_offset = block->link.next_offset;
put_ptr_atomic(tmpblock, KM_USER1);
}
if (block->link.next_page) {
tmpblock = get_ptr_atomic(block->link.next_page,
block->link.next_offset, KM_USER1);
tmpblock->link.prev_page = block->link.prev_page;
tmpblock->link.prev_offset = block->link.prev_offset;
put_ptr_atomic(tmpblock, KM_USER1);
}
/* Is this block is at the head of the freelist? */
if (pool->freelist[slindex].page == page
&& pool->freelist[slindex].offset == offset) {
pool->freelist[slindex].page = block->link.next_page;
pool->freelist[slindex].offset = block->link.next_offset;
if (pool->freelist[slindex].page) {
struct block_header *tmpblock;
tmpblock = get_ptr_atomic(pool->freelist[slindex].page,
pool->freelist[slindex].offset,
KM_USER1);
tmpblock->link.prev_page = NULL;
tmpblock->link.prev_offset = 0;
put_ptr_atomic(tmpblock, KM_USER1);
} else {
/* This freelist bucket is empty */
__clear_bit(slindex % BITS_PER_LONG,
&pool->slbitmap[flindex]);
if (!pool->slbitmap[flindex])
__clear_bit(flindex, &pool->flbitmap);
}
}
block->link.prev_page = NULL;
block->link.prev_offset = 0;
block->link.next_page = NULL;
block->link.next_offset = 0;
}
/*
* Allocate a page and add it to freelist of given pool.
*/
static int grow_pool(struct xv_pool *pool, gfp_t flags)
{
struct page *page;
struct block_header *block;
page = alloc_page(flags);
if (unlikely(!page))
return -ENOMEM;
stat_inc(&pool->total_pages);
spin_lock(&pool->lock);
block = get_ptr_atomic(page, 0, KM_USER0);
block->size = PAGE_SIZE - XV_ALIGN;
set_flag(block, BLOCK_FREE);
clear_flag(block, PREV_FREE);
set_blockprev(block, 0);
insert_block(pool, page, 0, block);
put_ptr_atomic(block, KM_USER0);
spin_unlock(&pool->lock);
return 0;
}
/*
* Create a memory pool. Allocates freelist, bitmaps and other
* per-pool metadata.
*/
struct xv_pool *xv_create_pool(void)
{
u32 ovhd_size;
struct xv_pool *pool;
ovhd_size = roundup(sizeof(*pool), PAGE_SIZE);
pool = kzalloc(ovhd_size, GFP_KERNEL);
if (!pool)
return NULL;
spin_lock_init(&pool->lock);
return pool;
}
EXPORT_SYMBOL_GPL(xv_create_pool);
void xv_destroy_pool(struct xv_pool *pool)
{
kfree(pool);
}
EXPORT_SYMBOL_GPL(xv_destroy_pool);
/**
* xv_malloc - Allocate block of given size from pool.
* @pool: pool to allocate from
* @size: size of block to allocate
* @page: page no. that holds the object
* @offset: location of object within page
*
* On success, <page, offset> identifies block allocated
* and 0 is returned. On failure, <page, offset> is set to
* 0 and -ENOMEM is returned.
*
* Allocation requests with size > XV_MAX_ALLOC_SIZE will fail.
*/
int xv_malloc(struct xv_pool *pool, u32 size, struct page **page,
u32 *offset, gfp_t flags)
{
int error;
u32 index, tmpsize, origsize, tmpoffset;
struct block_header *block, *tmpblock;
*page = NULL;
*offset = 0;
origsize = size;
if (unlikely(!size || size > XV_MAX_ALLOC_SIZE))
return -ENOMEM;
size = ALIGN(size, XV_ALIGN);
spin_lock(&pool->lock);
index = find_block(pool, size, page, offset);
if (!*page) {
spin_unlock(&pool->lock);
if (flags & GFP_NOWAIT)
return -ENOMEM;
error = grow_pool(pool, flags);
if (unlikely(error))
return error;
spin_lock(&pool->lock);
index = find_block(pool, size, page, offset);
}
if (!*page) {
spin_unlock(&pool->lock);
return -ENOMEM;
}
block = get_ptr_atomic(*page, *offset, KM_USER0);
remove_block(pool, *page, *offset, block, index);
/* Split the block if required */
tmpoffset = *offset + size + XV_ALIGN;
tmpsize = block->size - size;
tmpblock = (struct block_header *)((char *)block + size + XV_ALIGN);
if (tmpsize) {
tmpblock->size = tmpsize - XV_ALIGN;
set_flag(tmpblock, BLOCK_FREE);
clear_flag(tmpblock, PREV_FREE);
set_blockprev(tmpblock, *offset);
if (tmpblock->size >= XV_MIN_ALLOC_SIZE)
insert_block(pool, *page, tmpoffset, tmpblock);
if (tmpoffset + XV_ALIGN + tmpblock->size != PAGE_SIZE) {
tmpblock = BLOCK_NEXT(tmpblock);
set_blockprev(tmpblock, tmpoffset);
}
} else {
/* This block is exact fit */
if (tmpoffset != PAGE_SIZE)
clear_flag(tmpblock, PREV_FREE);
}
block->size = origsize;
clear_flag(block, BLOCK_FREE);
put_ptr_atomic(block, KM_USER0);
spin_unlock(&pool->lock);
*offset += XV_ALIGN;
return 0;
}
EXPORT_SYMBOL_GPL(xv_malloc);
/*
* Free block identified with <page, offset>
*/
void xv_free(struct xv_pool *pool, struct page *page, u32 offset)
{
void *page_start;
struct block_header *block, *tmpblock;
offset -= XV_ALIGN;
spin_lock(&pool->lock);
page_start = get_ptr_atomic(page, 0, KM_USER0);
block = (struct block_header *)((char *)page_start + offset);
/* Catch double free bugs */
BUG_ON(test_flag(block, BLOCK_FREE));
block->size = ALIGN(block->size, XV_ALIGN);
tmpblock = BLOCK_NEXT(block);
if (offset + block->size + XV_ALIGN == PAGE_SIZE)
tmpblock = NULL;
/* Merge next block if its free */
if (tmpblock && test_flag(tmpblock, BLOCK_FREE)) {
/*
* Blocks smaller than XV_MIN_ALLOC_SIZE
* are not inserted in any free list.
*/
if (tmpblock->size >= XV_MIN_ALLOC_SIZE) {
remove_block(pool, page,
offset + block->size + XV_ALIGN, tmpblock,
get_index_for_insert(tmpblock->size));
}
block->size += tmpblock->size + XV_ALIGN;
}
/* Merge previous block if its free */
if (test_flag(block, PREV_FREE)) {
tmpblock = (struct block_header *)((char *)(page_start) +
get_blockprev(block));
offset = offset - tmpblock->size - XV_ALIGN;
if (tmpblock->size >= XV_MIN_ALLOC_SIZE)
remove_block(pool, page, offset, tmpblock,
get_index_for_insert(tmpblock->size));
tmpblock->size += block->size + XV_ALIGN;
block = tmpblock;
}
/* No used objects in this page. Free it. */
if (block->size == PAGE_SIZE - XV_ALIGN) {
put_ptr_atomic(page_start, KM_USER0);
spin_unlock(&pool->lock);
__free_page(page);
stat_dec(&pool->total_pages);
return;
}
set_flag(block, BLOCK_FREE);
if (block->size >= XV_MIN_ALLOC_SIZE)
insert_block(pool, page, offset, block);
if (offset + block->size + XV_ALIGN != PAGE_SIZE) {
tmpblock = BLOCK_NEXT(block);
set_flag(tmpblock, PREV_FREE);
set_blockprev(tmpblock, offset);
}
put_ptr_atomic(page_start, KM_USER0);
spin_unlock(&pool->lock);
}
EXPORT_SYMBOL_GPL(xv_free);
u32 xv_get_object_size(void *obj)
{
struct block_header *blk;
blk = (struct block_header *)((char *)(obj) - XV_ALIGN);
return blk->size;
}
EXPORT_SYMBOL_GPL(xv_get_object_size);
/*
* Returns total memory used by allocator (userdata + metadata)
*/
u64 xv_get_total_size_bytes(struct xv_pool *pool)
{
return pool->total_pages << PAGE_SHIFT;
}
EXPORT_SYMBOL_GPL(xv_get_total_size_bytes);
drivers/staging/zram/xvmalloc.h deleted 100644 → 0
View file @ fd1a30de
/*
* xvmalloc memory allocator
*
* Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
*
* Released under the terms of 3-clause BSD License
* Released under the terms of GNU General Public License Version 2.0
*/
#ifndef _XV_MALLOC_H_
#define _XV_MALLOC_H_
#include <linux/types.h>
struct xv_pool;
struct xv_pool *xv_create_pool(void);
void xv_destroy_pool(struct xv_pool *pool);
int xv_malloc(struct xv_pool *pool, u32 size, struct page **page,
u32 *offset, gfp_t flags);
void xv_free(struct xv_pool *pool, struct page *page, u32 offset);
u32 xv_get_object_size(void *obj);
u64 xv_get_total_size_bytes(struct xv_pool *pool);
#endif
drivers/staging/zram/xvmalloc_int.h deleted 100644 → 0
View file @ fd1a30de
/*
* xvmalloc memory allocator
*
* Copyright (C) 2008, 2009, 2010 Nitin Gupta
*
* This code is released using a dual license strategy: BSD/GPL
* You can choose the licence that better fits your requirements.
*
* Released under the terms of 3-clause BSD License
* Released under the terms of GNU General Public License Version 2.0
*/
#ifndef _XV_MALLOC_INT_H_
#define _XV_MALLOC_INT_H_
#include <linux/kernel.h>
#include <linux/types.h>
/* User configurable params */
/* Must be power of two */
#ifdef CONFIG_64BIT
#define XV_ALIGN_SHIFT 3
#else
#define XV_ALIGN_SHIFT 2
#endif
#define XV_ALIGN (1 << XV_ALIGN_SHIFT)
#define XV_ALIGN_MASK (XV_ALIGN - 1)
/* This must be greater than sizeof(link_free) */
#define XV_MIN_ALLOC_SIZE 32
#define XV_MAX_ALLOC_SIZE (PAGE_SIZE - XV_ALIGN)
/*
* Free lists are separated by FL_DELTA bytes
* This value is 3 for 4k pages and 4 for 64k pages, for any
* other page size, a conservative (PAGE_SHIFT - 9) is used.
*/
#if PAGE_SHIFT == 16
#define FL_DELTA_SHIFT 4
#else
#define FL_DELTA_SHIFT (PAGE_SHIFT - 9)
#endif
#define FL_DELTA (1 << FL_DELTA_SHIFT)
#define FL_DELTA_MASK (FL_DELTA - 1)
#define NUM_FREE_LISTS ((XV_MAX_ALLOC_SIZE - XV_MIN_ALLOC_SIZE) \
/ FL_DELTA + 1)
#define MAX_FLI DIV_ROUND_UP(NUM_FREE_LISTS, BITS_PER_LONG)
/* End of user params */
enum blockflags {
BLOCK_FREE,
PREV_FREE,
__NR_BLOCKFLAGS,
};
#define FLAGS_MASK XV_ALIGN_MASK
#define PREV_MASK (~FLAGS_MASK)
struct freelist_entry {
struct page *page;
u16 offset;
u16 pad;
};
struct link_free {
struct page *prev_page;
struct page *next_page;
u16 prev_offset;
u16 next_offset;
};
struct block_header {
union {
/* This common header must be XV_ALIGN bytes */
u8 common[XV_ALIGN];
struct {
u16 size;
u16 prev;
};
};
struct link_free link;
};
struct xv_pool {
ulong flbitmap;
ulong slbitmap[MAX_FLI];
u64 total_pages; /* stats */
struct freelist_entry freelist[NUM_FREE_LISTS];
spinlock_t lock;
};
#endif
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