[openib-general] [PATCH v4 3/3] ofed_1_2 Provide generic allocator backport to 2.6.20.
Steve Wise
swise at opengridcomputing.com
Mon Jan 15 05:56:42 PST 2007
This is needed even on kernels that might have genalloc because it
may not be configured into the running kernel. Right now the only
subsystem that turns on the generic allocator config option is IA64.
So chances are good that 2.6.20 kernels will _not_ have this compiled in.
So we just backport it to all supported kernels.
To avoid collisions with kernels that _do_ have this compiled in,
change the names of the exported symbols in the backport.
Changes to genalloc.h:
- Change exported symbol names by prepending ib_
- added #defines for original exported symbol names to new names. Thus
code calling the allocator doesn't need to change.
EG: #define gen_pool_alloc ib_gen_pool alloc
Signed-off-by: Steve Wise <swise at opengridcomputing.com>
---
.../backport/2.6.20/include/linux/genalloc.h | 42 +++++
.../backport/2.6.20/include/src/genalloc.c | 198 +++++++++++++++++++++++
.../backport/2.6.20/linux_genalloc_to_2.6.20.patch | 17 ++
3 files changed, 257 insertions(+), 0 deletions(-)
diff --git a/kernel_addons/backport/2.6.20/include/linux/genalloc.h b/kernel_addons/backport/2.6.20/include/linux/genalloc.h
new file mode 100644
index 0000000..3c23c68
--- /dev/null
+++ b/kernel_addons/backport/2.6.20/include/linux/genalloc.h
@@ -0,0 +1,42 @@
+/*
+ * Basic general purpose allocator for managing special purpose memory
+ * not managed by the regular kmalloc/kfree interface.
+ * Uses for this includes on-device special memory, uncached memory
+ * etc.
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+
+/*
+ * General purpose special memory pool descriptor.
+ */
+struct gen_pool {
+ rwlock_t lock;
+ struct list_head chunks; /* list of chunks in this pool */
+ int min_alloc_order; /* minimum allocation order */
+};
+
+/*
+ * General purpose special memory pool chunk descriptor.
+ */
+struct gen_pool_chunk {
+ spinlock_t lock;
+ 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 */
+};
+
+extern struct gen_pool *ib_gen_pool_create(int, int);
+extern int ib_gen_pool_add(struct gen_pool *, unsigned long, size_t, int);
+extern void ib_gen_pool_destroy(struct gen_pool *);
+extern unsigned long ib_gen_pool_alloc(struct gen_pool *, size_t);
+extern void ib_gen_pool_free(struct gen_pool *, unsigned long, size_t);
+
+#define gen_pool_create ib_gen_pool_create
+#define gen_pool_add ib_gen_pool_add
+#define gen_pool_destroy ib_gen_pool_destroy
+#define gen_pool_alloc ib_gen_pool_alloc
+#define gen_pool_free ib_gen_pool_free
diff --git a/kernel_addons/backport/2.6.20/include/src/genalloc.c b/kernel_addons/backport/2.6.20/include/src/genalloc.c
new file mode 100644
index 0000000..75ae68c
--- /dev/null
+++ b/kernel_addons/backport/2.6.20/include/src/genalloc.c
@@ -0,0 +1,198 @@
+/*
+ * Basic general purpose allocator for managing special purpose memory
+ * not managed by the regular kmalloc/kfree interface.
+ * Uses for this includes on-device special memory, uncached memory
+ * etc.
+ *
+ * Copyright 2005 (C) Jes Sorensen <jes at trained-monkey.org>
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2. See the file COPYING for more details.
+ */
+
+#include <linux/module.h>
+#include <linux/genalloc.h>
+
+
+/**
+ * gen_pool_create - 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
+ *
+ * Create a new special memory pool that can be used to manage special purpose
+ * memory not managed by the regular kmalloc/kfree interface.
+ */
+struct gen_pool *gen_pool_create(int min_alloc_order, int nid)
+{
+ struct gen_pool *pool;
+
+ 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);
+
+/**
+ * gen_pool_add - add a new chunk of special memory to the 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
+ *
+ * Add a new chunk of special memory to the specified pool.
+ */
+int gen_pool_add(struct gen_pool *pool, unsigned long addr, size_t size,
+ int nid)
+{
+ 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;
+
+ chunk = kmalloc_node(nbytes, GFP_KERNEL, nid);
+ if (unlikely(chunk == NULL))
+ return -1;
+
+ memset(chunk, 0, nbytes);
+ spin_lock_init(&chunk->lock);
+ chunk->start_addr = addr;
+ chunk->end_addr = addr + size;
+
+ write_lock(&pool->lock);
+ list_add(&chunk->next_chunk, &pool->chunks);
+ write_unlock(&pool->lock);
+
+ return 0;
+}
+EXPORT_SYMBOL(gen_pool_add);
+
+/**
+ * gen_pool_destroy - destroy a special memory pool
+ * @pool: pool to destroy
+ *
+ * Destroy the specified special memory pool. Verifies that there are no
+ * outstanding allocations.
+ */
+void gen_pool_destroy(struct gen_pool *pool)
+{
+ struct list_head *_chunk, *_next_chunk;
+ struct gen_pool_chunk *chunk;
+ int order = pool->min_alloc_order;
+ int bit, end_bit;
+
+
+ write_lock(&pool->lock);
+ list_for_each_safe(_chunk, _next_chunk, &pool->chunks) {
+ chunk = list_entry(_chunk, struct gen_pool_chunk, next_chunk);
+ list_del(&chunk->next_chunk);
+
+ end_bit = (chunk->end_addr - chunk->start_addr) >> order;
+ bit = find_next_bit(chunk->bits, end_bit, 0);
+ BUG_ON(bit < end_bit);
+
+ kfree(chunk);
+ }
+ kfree(pool);
+ return;
+}
+EXPORT_SYMBOL(gen_pool_destroy);
+
+/**
+ * gen_pool_alloc - allocate special memory from the pool
+ * @pool: pool to allocate from
+ * @size: number of bytes to allocate from the pool
+ *
+ * Allocate the requested number of bytes from the specified pool.
+ * Uses a first-fit algorithm.
+ */
+unsigned long gen_pool_alloc(struct gen_pool *pool, size_t size)
+{
+ 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 == 0)
+ return 0;
+
+ 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;
+ }
+ spin_unlock_irqrestore(&chunk->lock, flags);
+ }
+ read_unlock(&pool->lock);
+ return 0;
+}
+EXPORT_SYMBOL(gen_pool_alloc);
+
+/**
+ * gen_pool_free - free allocated special memory back to the pool
+ * @pool: pool to free to
+ * @addr: starting address of memory to free back to pool
+ * @size: size in bytes of memory to free
+ *
+ * Free previously allocated special memory back to the specified pool.
+ */
+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;
+ }
+ }
+ BUG_ON(nbits > 0);
+ read_unlock(&pool->lock);
+}
+EXPORT_SYMBOL(gen_pool_free);
diff --git a/kernel_patches/backport/2.6.20/linux_genalloc_to_2.6.20.patch b/kernel_patches/backport/2.6.20/linux_genalloc_to_2.6.20.patch
new file mode 100644
index 0000000..93fee2b
--- /dev/null
+++ b/kernel_patches/backport/2.6.20/linux_genalloc_to_2.6.20.patch
@@ -0,0 +1,17 @@
+diff --git a/drivers/infiniband/core/Makefile b/drivers/infiniband/core/Makefile
+index 163d991..2cd239f 100644
+--- a/drivers/infiniband/core/Makefile
++++ b/drivers/infiniband/core/Makefile
+@@ -30,3 +30,5 @@ ib_ucm-y := ucm.o
+
+ ib_uverbs-y := uverbs_main.o uverbs_cmd.o uverbs_mem.o \
+ uverbs_marshall.o
++
++ib_core-y += genalloc.o
+diff --git a/drivers/infiniband/core/genalloc.c b/drivers/infiniband/core/genalloc.c
+new file mode 100644
+index 0000000..96a48fe
+--- /dev/null
++++ b/drivers/infiniband/core/genalloc.c
+@@ -0,0 +1 @@
++#include "src/genalloc.c"
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