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authorDean Nelson <dcn@sgi.com>2006-06-23 09:03:21 (GMT)
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-23 14:42:49 (GMT)
commit929f97276bcf7f4a95272ed08a85339b98ba210d (patch)
tree4975698af9559279c83e4e268213ed13e3efee9a
parent833423143c3a7c6545e409d65febd0d92deb351b (diff)
[PATCH] change gen_pool allocator to not touch managed memory
Modify the gen_pool allocator (lib/genalloc.c) to utilize a bitmap scheme instead of the buddy scheme. The purpose of this change is to eliminate the touching of the actual memory being allocated. Since the change modifies the interface, a change to the uncached allocator (arch/ia64/kernel/uncached.c) is also required. Both Andrey Volkov and Jes Sorenson have expressed a desire that the gen_pool allocator not write to the memory being managed. See the following: http://marc.theaimsgroup.com/?l=linux-kernel&m=113518602713125&w=2 http://marc.theaimsgroup.com/?l=linux-kernel&m=113533568827916&w=2 Signed-off-by: Dean Nelson <dcn@sgi.com> Cc: Andrey Volkov <avolkov@varma-el.com> Acked-by: Jes Sorensen <jes@trained-monkey.org> Cc: "Luck, Tony" <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--arch/ia64/kernel/uncached.c200
-rw-r--r--arch/ia64/sn/kernel/sn2/cache.c15
-rw-r--r--include/linux/genalloc.h35
-rw-r--r--lib/genalloc.c263
4 files changed, 252 insertions, 261 deletions
diff --git a/arch/ia64/kernel/uncached.c b/arch/ia64/kernel/uncached.c
index fcd2bad..5f03b9e 100644
--- a/arch/ia64/kernel/uncached.c
+++ b/arch/ia64/kernel/uncached.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2001-2005 Silicon Graphics, Inc. All rights reserved.
+ * Copyright (C) 2001-2006 Silicon Graphics, Inc. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 of the GNU General Public License
@@ -29,15 +29,8 @@
#include <asm/tlbflush.h>
#include <asm/sn/arch.h>
-#define DEBUG 0
-#if DEBUG
-#define dprintk printk
-#else
-#define dprintk(x...) do { } while (0)
-#endif
-
-void __init efi_memmap_walk_uc (efi_freemem_callback_t callback);
+extern void __init efi_memmap_walk_uc(efi_freemem_callback_t, void *);
#define MAX_UNCACHED_GRANULES 5
static int allocated_granules;
@@ -60,6 +53,7 @@ static void uncached_ipi_visibility(void *data)
static void uncached_ipi_mc_drain(void *data)
{
int status;
+
status = ia64_pal_mc_drain();
if (status)
printk(KERN_WARNING "ia64_pal_mc_drain() failed with %i on "
@@ -67,30 +61,35 @@ static void uncached_ipi_mc_drain(void *data)
}
-static unsigned long
-uncached_get_new_chunk(struct gen_pool *poolp)
+/*
+ * Add a new chunk of uncached memory pages to the specified pool.
+ *
+ * @pool: pool to add new chunk of uncached memory to
+ * @nid: node id of node to allocate memory from, or -1
+ *
+ * This is accomplished by first allocating a granule of cached memory pages
+ * and then converting them to uncached memory pages.
+ */
+static int uncached_add_chunk(struct gen_pool *pool, int nid)
{
struct page *page;
- void *tmp;
int status, i;
- unsigned long addr, node;
+ unsigned long c_addr, uc_addr;
if (allocated_granules >= MAX_UNCACHED_GRANULES)
- return 0;
+ return -1;
+
+ /* attempt to allocate a granule's worth of cached memory pages */
- node = poolp->private;
- page = alloc_pages_node(node, GFP_KERNEL | __GFP_ZERO,
+ page = alloc_pages_node(nid, GFP_KERNEL | __GFP_ZERO,
IA64_GRANULE_SHIFT-PAGE_SHIFT);
+ if (!page)
+ return -1;
- dprintk(KERN_INFO "get_new_chunk page %p, addr %lx\n",
- page, (unsigned long)(page-vmem_map) << PAGE_SHIFT);
+ /* convert the memory pages from cached to uncached */
- /*
- * Do magic if no mem on local node! XXX
- */
- if (!page)
- return 0;
- tmp = page_address(page);
+ c_addr = (unsigned long)page_address(page);
+ uc_addr = c_addr - PAGE_OFFSET + __IA64_UNCACHED_OFFSET;
/*
* There's a small race here where it's possible for someone to
@@ -100,76 +99,90 @@ uncached_get_new_chunk(struct gen_pool *poolp)
for (i = 0; i < (IA64_GRANULE_SIZE / PAGE_SIZE); i++)
SetPageUncached(&page[i]);
- flush_tlb_kernel_range(tmp, tmp + IA64_GRANULE_SIZE);
+ flush_tlb_kernel_range(uc_addr, uc_adddr + IA64_GRANULE_SIZE);
status = ia64_pal_prefetch_visibility(PAL_VISIBILITY_PHYSICAL);
-
- dprintk(KERN_INFO "pal_prefetch_visibility() returns %i on cpu %i\n",
- status, raw_smp_processor_id());
-
if (!status) {
status = smp_call_function(uncached_ipi_visibility, NULL, 0, 1);
if (status)
- printk(KERN_WARNING "smp_call_function failed for "
- "uncached_ipi_visibility! (%i)\n", status);
+ goto failed;
}
+ preempt_disable();
+
if (ia64_platform_is("sn2"))
- sn_flush_all_caches((unsigned long)tmp, IA64_GRANULE_SIZE);
+ sn_flush_all_caches(uc_addr, IA64_GRANULE_SIZE);
else
- flush_icache_range((unsigned long)tmp,
- (unsigned long)tmp+IA64_GRANULE_SIZE);
+ flush_icache_range(uc_addr, uc_addr + IA64_GRANULE_SIZE);
+
+ /* flush the just introduced uncached translation from the TLB */
+ local_flush_tlb_all();
+
+ preempt_enable();
ia64_pal_mc_drain();
status = smp_call_function(uncached_ipi_mc_drain, NULL, 0, 1);
if (status)
- printk(KERN_WARNING "smp_call_function failed for "
- "uncached_ipi_mc_drain! (%i)\n", status);
+ goto failed;
- addr = (unsigned long)tmp - PAGE_OFFSET + __IA64_UNCACHED_OFFSET;
+ /*
+ * The chunk of memory pages has been converted to uncached so now we
+ * can add it to the pool.
+ */
+ status = gen_pool_add(pool, uc_addr, IA64_GRANULE_SIZE, nid);
+ if (status)
+ goto failed;
allocated_granules++;
- return addr;
+ return 0;
+
+ /* failed to convert or add the chunk so give it back to the kernel */
+failed:
+ for (i = 0; i < (IA64_GRANULE_SIZE / PAGE_SIZE); i++)
+ ClearPageUncached(&page[i]);
+
+ free_pages(c_addr, IA64_GRANULE_SHIFT-PAGE_SHIFT);
+ return -1;
}
/*
* uncached_alloc_page
*
+ * @starting_nid: node id of node to start with, or -1
+ *
* Allocate 1 uncached page. Allocates on the requested node. If no
* uncached pages are available on the requested node, roundrobin starting
- * with higher nodes.
+ * with the next higher node.
*/
-unsigned long
-uncached_alloc_page(int nid)
+unsigned long uncached_alloc_page(int starting_nid)
{
- unsigned long maddr;
+ unsigned long uc_addr;
+ struct gen_pool *pool;
+ int nid;
- maddr = gen_pool_alloc(uncached_pool[nid], PAGE_SIZE);
+ if (unlikely(starting_nid >= MAX_NUMNODES))
+ return 0;
- dprintk(KERN_DEBUG "uncached_alloc_page returns %lx on node %i\n",
- maddr, nid);
+ if (starting_nid < 0)
+ starting_nid = numa_node_id();
+ nid = starting_nid;
- /*
- * If no memory is availble on our local node, try the
- * remaining nodes in the system.
- */
- if (!maddr) {
- int i;
-
- for (i = MAX_NUMNODES - 1; i >= 0; i--) {
- if (i == nid || !node_online(i))
- continue;
- maddr = gen_pool_alloc(uncached_pool[i], PAGE_SIZE);
- dprintk(KERN_DEBUG "uncached_alloc_page alternate search "
- "returns %lx on node %i\n", maddr, i);
- if (maddr) {
- break;
- }
- }
- }
+ do {
+ if (!node_online(nid))
+ continue;
+ pool = uncached_pool[nid];
+ if (pool == NULL)
+ continue;
+ do {
+ uc_addr = gen_pool_alloc(pool, PAGE_SIZE);
+ if (uc_addr != 0)
+ return uc_addr;
+ } while (uncached_add_chunk(pool, nid) == 0);
+
+ } while ((nid = (nid + 1) % MAX_NUMNODES) != starting_nid);
- return maddr;
+ return 0;
}
EXPORT_SYMBOL(uncached_alloc_page);
@@ -177,21 +190,22 @@ EXPORT_SYMBOL(uncached_alloc_page);
/*
* uncached_free_page
*
+ * @uc_addr: uncached address of page to free
+ *
* Free a single uncached page.
*/
-void
-uncached_free_page(unsigned long maddr)
+void uncached_free_page(unsigned long uc_addr)
{
- int node;
-
- node = paddr_to_nid(maddr - __IA64_UNCACHED_OFFSET);
+ int nid = paddr_to_nid(uc_addr - __IA64_UNCACHED_OFFSET);
+ struct gen_pool *pool = uncached_pool[nid];
- dprintk(KERN_DEBUG "uncached_free_page(%lx) on node %i\n", maddr, node);
+ if (unlikely(pool == NULL))
+ return;
- if ((maddr & (0XFUL << 60)) != __IA64_UNCACHED_OFFSET)
- panic("uncached_free_page invalid address %lx\n", maddr);
+ if ((uc_addr & (0XFUL << 60)) != __IA64_UNCACHED_OFFSET)
+ panic("uncached_free_page invalid address %lx\n", uc_addr);
- gen_pool_free(uncached_pool[node], maddr, PAGE_SIZE);
+ gen_pool_free(pool, uc_addr, PAGE_SIZE);
}
EXPORT_SYMBOL(uncached_free_page);
@@ -199,43 +213,39 @@ EXPORT_SYMBOL(uncached_free_page);
/*
* uncached_build_memmap,
*
+ * @uc_start: uncached starting address of a chunk of uncached memory
+ * @uc_end: uncached ending address of a chunk of uncached memory
+ * @arg: ignored, (NULL argument passed in on call to efi_memmap_walk_uc())
+ *
* Called at boot time to build a map of pages that can be used for
* memory special operations.
*/
-static int __init
-uncached_build_memmap(unsigned long start, unsigned long end, void *arg)
+static int __init uncached_build_memmap(unsigned long uc_start,
+ unsigned long uc_end, void *arg)
{
- long length = end - start;
- int node;
-
- dprintk(KERN_ERR "uncached_build_memmap(%lx %lx)\n", start, end);
+ int nid = paddr_to_nid(uc_start - __IA64_UNCACHED_OFFSET);
+ struct gen_pool *pool = uncached_pool[nid];
+ size_t size = uc_end - uc_start;
touch_softlockup_watchdog();
- memset((char *)start, 0, length);
- node = paddr_to_nid(start - __IA64_UNCACHED_OFFSET);
-
- for (; start < end ; start += PAGE_SIZE) {
- dprintk(KERN_INFO "sticking %lx into the pool!\n", start);
- gen_pool_free(uncached_pool[node], start, PAGE_SIZE);
+ if (pool != NULL) {
+ memset((char *)uc_start, 0, size);
+ (void) gen_pool_add(pool, uc_start, size, nid);
}
-
return 0;
}
-static int __init uncached_init(void) {
- int i;
+static int __init uncached_init(void)
+{
+ int nid;
- for (i = 0; i < MAX_NUMNODES; i++) {
- if (!node_online(i))
- continue;
- uncached_pool[i] = gen_pool_create(0, IA64_GRANULE_SHIFT,
- &uncached_get_new_chunk, i);
+ for_each_online_node(nid) {
+ uncached_pool[nid] = gen_pool_create(PAGE_SHIFT, nid);
}
- efi_memmap_walk_uc(uncached_build_memmap);
-
+ efi_memmap_walk_uc(uncached_build_memmap, NULL);
return 0;
}
diff --git a/arch/ia64/sn/kernel/sn2/cache.c b/arch/ia64/sn/kernel/sn2/cache.c
index bc3cfa1..2862cb3 100644
--- a/arch/ia64/sn/kernel/sn2/cache.c
+++ b/arch/ia64/sn/kernel/sn2/cache.c
@@ -3,11 +3,12 @@
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
- * Copyright (C) 2001-2003 Silicon Graphics, Inc. All rights reserved.
+ * Copyright (C) 2001-2003, 2006 Silicon Graphics, Inc. All rights reserved.
*
*/
#include <linux/module.h>
#include <asm/pgalloc.h>
+#include <asm/sn/arch.h>
/**
* sn_flush_all_caches - flush a range of address from all caches (incl. L4)
@@ -17,18 +18,24 @@
* Flush a range of addresses from all caches including L4.
* All addresses fully or partially contained within
* @flush_addr to @flush_addr + @bytes are flushed
- * from the all caches.
+ * from all caches.
*/
void
sn_flush_all_caches(long flush_addr, long bytes)
{
- flush_icache_range(flush_addr, flush_addr+bytes);
+ unsigned long addr = flush_addr;
+
+ /* SHub1 requires a cached address */
+ if (is_shub1() && (addr & RGN_BITS) == RGN_BASE(RGN_UNCACHED))
+ addr = (addr - RGN_BASE(RGN_UNCACHED)) + RGN_BASE(RGN_KERNEL);
+
+ flush_icache_range(addr, addr + bytes);
/*
* The last call may have returned before the caches
* were actually flushed, so we call it again to make
* sure.
*/
- flush_icache_range(flush_addr, flush_addr+bytes);
+ flush_icache_range(addr, addr + bytes);
mb();
}
EXPORT_SYMBOL(sn_flush_all_caches);
diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h
index 7fd0576..690c428 100644
--- a/include/linux/genalloc.h
+++ b/include/linux/genalloc.h
@@ -4,37 +4,32 @@
* Uses for this includes on-device special memory, uncached memory
* etc.
*
- * This code is based on the buddy allocator found in the sym53c8xx_2
- * driver, adapted for general purpose use.
- *
* This source code is licensed under the GNU General Public License,
* Version 2. See the file COPYING for more details.
*/
-#include <linux/spinlock.h>
-#define ALLOC_MIN_SHIFT 5 /* 32 bytes minimum */
/*
- * Link between free memory chunks of a given size.
+ * General purpose special memory pool descriptor.
*/
-struct gen_pool_link {
- struct gen_pool_link *next;
+struct gen_pool {
+ rwlock_t lock;
+ struct list_head chunks; /* list of chunks in this pool */
+ int min_alloc_order; /* minimum allocation order */
};
/*
- * Memory pool descriptor.
+ * General purpose special memory pool chunk descriptor.
*/
-struct gen_pool {
+struct gen_pool_chunk {
spinlock_t lock;
- unsigned long (*get_new_chunk)(struct gen_pool *);
- struct gen_pool *next;
- struct gen_pool_link *h;
- unsigned long private;
- int max_chunk_shift;
+ struct list_head next_chunk; /* next chunk in pool */
+ unsigned long start_addr; /* starting address of memory chunk */
+ unsigned long end_addr; /* ending address of memory chunk */
+ unsigned long bits[0]; /* bitmap for allocating memory chunk */
};
-unsigned long gen_pool_alloc(struct gen_pool *poolp, int size);
-void gen_pool_free(struct gen_pool *mp, unsigned long ptr, int size);
-struct gen_pool *gen_pool_create(int nr_chunks, int max_chunk_shift,
- unsigned long (*fp)(struct gen_pool *),
- unsigned long data);
+extern struct gen_pool *gen_pool_create(int, int);
+extern int gen_pool_add(struct gen_pool *, unsigned long, size_t, int);
+extern unsigned long gen_pool_alloc(struct gen_pool *, size_t);
+extern void gen_pool_free(struct gen_pool *, unsigned long, size_t);
diff --git a/lib/genalloc.c b/lib/genalloc.c
index 9ce0a6a..71338b4 100644
--- a/lib/genalloc.c
+++ b/lib/genalloc.c
@@ -4,10 +4,6 @@
* Uses for this includes on-device special memory, uncached memory
* etc.
*
- * This code is based on the buddy allocator found in the sym53c8xx_2
- * driver Copyright (C) 1999-2001 Gerard Roudier <groudier@free.fr>,
- * and adapted for general purpose use.
- *
* Copyright 2005 (C) Jes Sorensen <jes@trained-monkey.org>
*
* This source code is licensed under the GNU General Public License,
@@ -15,172 +11,155 @@
*/
#include <linux/module.h>
-#include <linux/stddef.h>
-#include <linux/kernel.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/init.h>
-#include <linux/mm.h>
-#include <linux/spinlock.h>
#include <linux/genalloc.h>
-#include <asm/page.h>
-
-struct gen_pool *gen_pool_create(int nr_chunks, int max_chunk_shift,
- unsigned long (*fp)(struct gen_pool *),
- unsigned long data)
+/*
+ * Create a new special memory pool.
+ *
+ * @min_alloc_order: log base 2 of number of bytes each bitmap bit represents
+ * @nid: node id of the node the pool structure should be allocated on, or -1
+ */
+struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
{
- struct gen_pool *poolp;
- unsigned long tmp;
- int i;
-
- /*
- * This is really an arbitrary limit, +10 is enough for
- * IA64_GRANULE_SHIFT, aka 16MB. If anyone needs a large limit
- * this can be increased without problems.
- */
- if ((max_chunk_shift > (PAGE_SHIFT + 10)) ||
- ((max_chunk_shift < ALLOC_MIN_SHIFT) && max_chunk_shift))
- return NULL;
-
- if (!max_chunk_shift)
- max_chunk_shift = PAGE_SHIFT;
-
- poolp = kmalloc(sizeof(struct gen_pool), GFP_KERNEL);
- if (!poolp)
- return NULL;
- memset(poolp, 0, sizeof(struct gen_pool));
- poolp->h = kmalloc(sizeof(struct gen_pool_link) *
- (max_chunk_shift - ALLOC_MIN_SHIFT + 1),
- GFP_KERNEL);
- if (!poolp->h) {
- printk(KERN_WARNING "gen_pool_alloc() failed to allocate\n");
- kfree(poolp);
- return NULL;
- }
- memset(poolp->h, 0, sizeof(struct gen_pool_link) *
- (max_chunk_shift - ALLOC_MIN_SHIFT + 1));
-
- spin_lock_init(&poolp->lock);
- poolp->get_new_chunk = fp;
- poolp->max_chunk_shift = max_chunk_shift;
- poolp->private = data;
-
- for (i = 0; i < nr_chunks; i++) {
- tmp = poolp->get_new_chunk(poolp);
- printk(KERN_INFO "allocated %lx\n", tmp);
- if (!tmp)
- break;
- gen_pool_free(poolp, tmp, (1 << poolp->max_chunk_shift));
- }
+ struct gen_pool *pool;
- return poolp;
+ pool = kmalloc_node(sizeof(struct gen_pool), GFP_KERNEL, nid);
+ if (pool != NULL) {
+ rwlock_init(&pool->lock);
+ INIT_LIST_HEAD(&pool->chunks);
+ pool->min_alloc_order = min_alloc_order;
+ }
+ return pool;
}
EXPORT_SYMBOL(gen_pool_create);
/*
- * Simple power of two buddy-like generic allocator.
- * Provides naturally aligned memory chunks.
+ * Add a new chunk of memory to the specified pool.
+ *
+ * @pool: pool to add new memory chunk to
+ * @addr: starting address of memory chunk to add to pool
+ * @size: size in bytes of the memory chunk to add to pool
+ * @nid: node id of the node the chunk structure and bitmap should be
+ * allocated on, or -1
*/
-unsigned long gen_pool_alloc(struct gen_pool *poolp, int size)
+int gen_pool_add(struct gen_pool *pool, unsigned long addr, size_t size,
+ int nid)
{
- int j, i, s, max_chunk_size;
- unsigned long a, flags;
- struct gen_pool_link *h = poolp->h;
+ struct gen_pool_chunk *chunk;
+ int nbits = size >> pool->min_alloc_order;
+ int nbytes = sizeof(struct gen_pool_chunk) +
+ (nbits + BITS_PER_BYTE - 1) / BITS_PER_BYTE;
- max_chunk_size = 1 << poolp->max_chunk_shift;
+ chunk = kmalloc_node(nbytes, GFP_KERNEL, nid);
+ if (unlikely(chunk == NULL))
+ return -1;
- if (size > max_chunk_size)
- return 0;
+ memset(chunk, 0, nbytes);
+ spin_lock_init(&chunk->lock);
+ chunk->start_addr = addr;
+ chunk->end_addr = addr + size;
- size = max(size, 1 << ALLOC_MIN_SHIFT);
- i = fls(size - 1);
- s = 1 << i;
- j = i -= ALLOC_MIN_SHIFT;
-
- spin_lock_irqsave(&poolp->lock, flags);
- while (!h[j].next) {
- if (s == max_chunk_size) {
- struct gen_pool_link *ptr;
- spin_unlock_irqrestore(&poolp->lock, flags);
- ptr = (struct gen_pool_link *)poolp->get_new_chunk(poolp);
- spin_lock_irqsave(&poolp->lock, flags);
- h[j].next = ptr;
- if (h[j].next)
- h[j].next->next = NULL;
- break;
- }
- j++;
- s <<= 1;
- }
- a = (unsigned long) h[j].next;
- if (a) {
- h[j].next = h[j].next->next;
- /*
- * This should be split into a seperate function doing
- * the chunk split in order to support custom
- * handling memory not physically accessible by host
- */
- while (j > i) {
- j -= 1;
- s >>= 1;
- h[j].next = (struct gen_pool_link *) (a + s);
- h[j].next->next = NULL;
- }
- }
- spin_unlock_irqrestore(&poolp->lock, flags);
- return a;
+ write_lock(&pool->lock);
+ list_add(&chunk->next_chunk, &pool->chunks);
+ write_unlock(&pool->lock);
+
+ return 0;
}
-EXPORT_SYMBOL(gen_pool_alloc);
+EXPORT_SYMBOL(gen_pool_add);
/*
- * Counter-part of the generic allocator.
+ * Allocate the requested number of bytes from the specified pool.
+ * Uses a first-fit algorithm.
+ *
+ * @pool: pool to allocate from
+ * @size: number of bytes to allocate from the pool
*/
-void gen_pool_free(struct gen_pool *poolp, unsigned long ptr, int size)
+unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
{
- struct gen_pool_link *q;
- struct gen_pool_link *h = poolp->h;
- unsigned long a, b, flags;
- int i, s, max_chunk_size;
-
- max_chunk_size = 1 << poolp->max_chunk_shift;
+ struct list_head *_chunk;
+ struct gen_pool_chunk *chunk;
+ unsigned long addr, flags;
+ int order = pool->min_alloc_order;
+ int nbits, bit, start_bit, end_bit;
- if (size > max_chunk_size)
- return;
-
- size = max(size, 1 << ALLOC_MIN_SHIFT);
- i = fls(size - 1);
- s = 1 << i;
- i -= ALLOC_MIN_SHIFT;
-
- a = ptr;
+ if (size == 0)
+ return 0;
- spin_lock_irqsave(&poolp->lock, flags);
- while (1) {
- if (s == max_chunk_size) {
- ((struct gen_pool_link *)a)->next = h[i].next;
- h[i].next = (struct gen_pool_link *)a;
- break;
+ nbits = (size + (1UL << order) - 1) >> order;
+
+ read_lock(&pool->lock);
+ list_for_each(_chunk, &pool->chunks) {
+ chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
+
+ end_bit = (chunk->end_addr - chunk->start_addr) >> order;
+ end_bit -= nbits + 1;
+
+ spin_lock_irqsave(&chunk->lock, flags);
+ bit = -1;
+ while (bit + 1 < end_bit) {
+ bit = find_next_zero_bit(chunk->bits, end_bit, bit + 1);
+ if (bit >= end_bit)
+ break;
+
+ start_bit = bit;
+ if (nbits > 1) {
+ bit = find_next_bit(chunk->bits, bit + nbits,
+ bit + 1);
+ if (bit - start_bit < nbits)
+ continue;
+ }
+
+ addr = chunk->start_addr +
+ ((unsigned long)start_bit << order);
+ while (nbits--)
+ __set_bit(start_bit++, &chunk->bits);
+ spin_unlock_irqrestore(&chunk->lock, flags);
+ read_unlock(&pool->lock);
+ return addr;
}
- b = a ^ s;
- q = &h[i];
+ spin_unlock_irqrestore(&chunk->lock, flags);
+ }
+ read_unlock(&pool->lock);
+ return 0;
+}
+EXPORT_SYMBOL(gen_pool_alloc);
- while (q->next && q->next != (struct gen_pool_link *)b)
- q = q->next;
- if (!q->next) {
- ((struct gen_pool_link *)a)->next = h[i].next;
- h[i].next = (struct gen_pool_link *)a;
+/*
+ * Free the specified memory back to the specified pool.
+ *
+ * @pool: pool to free to
+ * @addr: starting address of memory to free back to pool
+ * @size: size in bytes of memory to free
+ */
+void gen_pool_free(struct gen_pool *pool, unsigned long addr, size_t size)
+{
+ struct list_head *_chunk;
+ struct gen_pool_chunk *chunk;
+ unsigned long flags;
+ int order = pool->min_alloc_order;
+ int bit, nbits;
+
+ nbits = (size + (1UL << order) - 1) >> order;
+
+ read_lock(&pool->lock);
+ list_for_each(_chunk, &pool->chunks) {
+ chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
+
+ if (addr >= chunk->start_addr && addr < chunk->end_addr) {
+ BUG_ON(addr + size > chunk->end_addr);
+ spin_lock_irqsave(&chunk->lock, flags);
+ bit = (addr - chunk->start_addr) >> order;
+ while (nbits--)
+ __clear_bit(bit++, &chunk->bits);
+ spin_unlock_irqrestore(&chunk->lock, flags);
break;
}
- q->next = q->next->next;
- a = a & b;
- s <<= 1;
- i++;
}
- spin_unlock_irqrestore(&poolp->lock, flags);
+ BUG_ON(nbits > 0);
+ read_unlock(&pool->lock);
}
EXPORT_SYMBOL(gen_pool_free);

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