[PATCH 2/2] mm/zbud: don't export any zbud API

From: Miaohe Lin
Date: Sat Jun 05 2021 - 03:53:40 EST


The zbud doesn't need to export any API and it is meant to be used via
zpool API since the commit 12d79d64bfd3 ("mm/zpool: update zswap to use
zpool"). So we can remove the unneeded zbud.h and move down zpool API
to avoid any forward declaration.

Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
---
MAINTAINERS | 1 -
include/linux/zbud.h | 23 -----
mm/zbud.c | 219 ++++++++++++++++++++++---------------------
3 files changed, 112 insertions(+), 131 deletions(-)
delete mode 100644 include/linux/zbud.h

diff --git a/MAINTAINERS b/MAINTAINERS
index d8648ee43199..625d66d7aacc 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20264,7 +20264,6 @@ M: Seth Jennings <sjenning@xxxxxxxxxx>
M: Dan Streetman <ddstreet@xxxxxxxx>
L: linux-mm@xxxxxxxxx
S: Maintained
-F: include/linux/zbud.h
F: mm/zbud.c

ZD1211RW WIRELESS DRIVER
diff --git a/include/linux/zbud.h b/include/linux/zbud.h
deleted file mode 100644
index b1eaf6e31735..000000000000
--- a/include/linux/zbud.h
+++ /dev/null
@@ -1,23 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ZBUD_H_
-#define _ZBUD_H_
-
-#include <linux/types.h>
-
-struct zbud_pool;
-
-struct zbud_ops {
- int (*evict)(struct zbud_pool *pool, unsigned long handle);
-};
-
-struct zbud_pool *zbud_create_pool(gfp_t gfp, const struct zbud_ops *ops);
-void zbud_destroy_pool(struct zbud_pool *pool);
-int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,
- unsigned long *handle);
-void zbud_free(struct zbud_pool *pool, unsigned long handle);
-int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries);
-void *zbud_map(struct zbud_pool *pool, unsigned long handle);
-void zbud_unmap(struct zbud_pool *pool, unsigned long handle);
-u64 zbud_get_pool_size(struct zbud_pool *pool);
-
-#endif /* _ZBUD_H_ */
diff --git a/mm/zbud.c b/mm/zbud.c
index 91543be47e3d..3a048f603255 100644
--- a/mm/zbud.c
+++ b/mm/zbud.c
@@ -51,7 +51,6 @@
#include <linux/preempt.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
-#include <linux/zbud.h>
#include <linux/zpool.h>

/*****************
@@ -73,6 +72,12 @@
#define ZHDR_SIZE_ALIGNED CHUNK_SIZE
#define NCHUNKS ((PAGE_SIZE - ZHDR_SIZE_ALIGNED) >> CHUNK_SHIFT)

+struct zbud_pool;
+
+struct zbud_ops {
+ int (*evict)(struct zbud_pool *pool, unsigned long handle);
+};
+
/**
* struct zbud_pool - stores metadata for each zbud pool
* @lock: protects all pool fields and first|last_chunk fields of any
@@ -122,104 +127,6 @@ struct zbud_header {
bool under_reclaim;
};

-/*****************
- * zpool
- ****************/
-
-#ifdef CONFIG_ZPOOL
-
-static int zbud_zpool_evict(struct zbud_pool *pool, unsigned long handle)
-{
- if (pool->zpool && pool->zpool_ops && pool->zpool_ops->evict)
- return pool->zpool_ops->evict(pool->zpool, handle);
- else
- return -ENOENT;
-}
-
-static const struct zbud_ops zbud_zpool_ops = {
- .evict = zbud_zpool_evict
-};
-
-static void *zbud_zpool_create(const char *name, gfp_t gfp,
- const struct zpool_ops *zpool_ops,
- struct zpool *zpool)
-{
- struct zbud_pool *pool;
-
- pool = zbud_create_pool(gfp, zpool_ops ? &zbud_zpool_ops : NULL);
- if (pool) {
- pool->zpool = zpool;
- pool->zpool_ops = zpool_ops;
- }
- return pool;
-}
-
-static void zbud_zpool_destroy(void *pool)
-{
- zbud_destroy_pool(pool);
-}
-
-static int zbud_zpool_malloc(void *pool, size_t size, gfp_t gfp,
- unsigned long *handle)
-{
- return zbud_alloc(pool, size, gfp, handle);
-}
-static void zbud_zpool_free(void *pool, unsigned long handle)
-{
- zbud_free(pool, handle);
-}
-
-static int zbud_zpool_shrink(void *pool, unsigned int pages,
- unsigned int *reclaimed)
-{
- unsigned int total = 0;
- int ret = -EINVAL;
-
- while (total < pages) {
- ret = zbud_reclaim_page(pool, 8);
- if (ret < 0)
- break;
- total++;
- }
-
- if (reclaimed)
- *reclaimed = total;
-
- return ret;
-}
-
-static void *zbud_zpool_map(void *pool, unsigned long handle,
- enum zpool_mapmode mm)
-{
- return zbud_map(pool, handle);
-}
-static void zbud_zpool_unmap(void *pool, unsigned long handle)
-{
- zbud_unmap(pool, handle);
-}
-
-static u64 zbud_zpool_total_size(void *pool)
-{
- return zbud_get_pool_size(pool) * PAGE_SIZE;
-}
-
-static struct zpool_driver zbud_zpool_driver = {
- .type = "zbud",
- .sleep_mapped = true,
- .owner = THIS_MODULE,
- .create = zbud_zpool_create,
- .destroy = zbud_zpool_destroy,
- .malloc = zbud_zpool_malloc,
- .free = zbud_zpool_free,
- .shrink = zbud_zpool_shrink,
- .map = zbud_zpool_map,
- .unmap = zbud_zpool_unmap,
- .total_size = zbud_zpool_total_size,
-};
-
-MODULE_ALIAS("zpool-zbud");
-#endif /* CONFIG_ZPOOL */
-
/*****************
* Helpers
*****************/
@@ -306,7 +213,7 @@ static int num_free_chunks(struct zbud_header *zhdr)
* Return: pointer to the new zbud pool or NULL if the metadata allocation
* failed.
*/
-struct zbud_pool *zbud_create_pool(gfp_t gfp, const struct zbud_ops *ops)
+static struct zbud_pool *zbud_create_pool(gfp_t gfp, const struct zbud_ops *ops)
{
struct zbud_pool *pool;
int i;
@@ -330,7 +237,7 @@ struct zbud_pool *zbud_create_pool(gfp_t gfp, const struct zbud_ops *ops)
*
* The pool should be emptied before this function is called.
*/
-void zbud_destroy_pool(struct zbud_pool *pool)
+static void zbud_destroy_pool(struct zbud_pool *pool)
{
kfree(pool);
}
@@ -354,7 +261,7 @@ void zbud_destroy_pool(struct zbud_pool *pool)
* gfp arguments are invalid or -ENOMEM if the pool was unable to allocate
* a new page.
*/
-int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,
+static int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,
unsigned long *handle)
{
int chunks, i, freechunks;
@@ -429,7 +336,7 @@ int zbud_alloc(struct zbud_pool *pool, size_t size, gfp_t gfp,
* only sets the first|last_chunks to 0. The page is actually freed
* once both buddies are evicted (see zbud_reclaim_page() below).
*/
-void zbud_free(struct zbud_pool *pool, unsigned long handle)
+static void zbud_free(struct zbud_pool *pool, unsigned long handle)
{
struct zbud_header *zhdr;
int freechunks;
@@ -501,7 +408,7 @@ void zbud_free(struct zbud_pool *pool, unsigned long handle)
* no pages to evict or an eviction handler is not registered, -EAGAIN if
* the retry limit was hit.
*/
-int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries)
+static int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries)
{
int i, ret, freechunks;
struct zbud_header *zhdr;
@@ -583,7 +490,7 @@ int zbud_reclaim_page(struct zbud_pool *pool, unsigned int retries)
*
* Returns: a pointer to the mapped allocation
*/
-void *zbud_map(struct zbud_pool *pool, unsigned long handle)
+static void *zbud_map(struct zbud_pool *pool, unsigned long handle)
{
return (void *)(handle);
}
@@ -593,7 +500,7 @@ void *zbud_map(struct zbud_pool *pool, unsigned long handle)
* @pool: pool in which the allocation resides
* @handle: handle associated with the allocation to be unmapped
*/
-void zbud_unmap(struct zbud_pool *pool, unsigned long handle)
+static void zbud_unmap(struct zbud_pool *pool, unsigned long handle)
{
}

@@ -604,11 +511,109 @@ void zbud_unmap(struct zbud_pool *pool, unsigned long handle)
* Returns: size in pages of the given pool. The pool lock need not be
* taken to access pages_nr.
*/
-u64 zbud_get_pool_size(struct zbud_pool *pool)
+static u64 zbud_get_pool_size(struct zbud_pool *pool)
{
return pool->pages_nr;
}

+/*****************
+ * zpool
+ ****************/
+
+#ifdef CONFIG_ZPOOL
+
+static int zbud_zpool_evict(struct zbud_pool *pool, unsigned long handle)
+{
+ if (pool->zpool && pool->zpool_ops && pool->zpool_ops->evict)
+ return pool->zpool_ops->evict(pool->zpool, handle);
+ else
+ return -ENOENT;
+}
+
+static const struct zbud_ops zbud_zpool_ops = {
+ .evict = zbud_zpool_evict
+};
+
+static void *zbud_zpool_create(const char *name, gfp_t gfp,
+ const struct zpool_ops *zpool_ops,
+ struct zpool *zpool)
+{
+ struct zbud_pool *pool;
+
+ pool = zbud_create_pool(gfp, zpool_ops ? &zbud_zpool_ops : NULL);
+ if (pool) {
+ pool->zpool = zpool;
+ pool->zpool_ops = zpool_ops;
+ }
+ return pool;
+}
+
+static void zbud_zpool_destroy(void *pool)
+{
+ zbud_destroy_pool(pool);
+}
+
+static int zbud_zpool_malloc(void *pool, size_t size, gfp_t gfp,
+ unsigned long *handle)
+{
+ return zbud_alloc(pool, size, gfp, handle);
+}
+static void zbud_zpool_free(void *pool, unsigned long handle)
+{
+ zbud_free(pool, handle);
+}
+
+static int zbud_zpool_shrink(void *pool, unsigned int pages,
+ unsigned int *reclaimed)
+{
+ unsigned int total = 0;
+ int ret = -EINVAL;
+
+ while (total < pages) {
+ ret = zbud_reclaim_page(pool, 8);
+ if (ret < 0)
+ break;
+ total++;
+ }
+
+ if (reclaimed)
+ *reclaimed = total;
+
+ return ret;
+}
+
+static void *zbud_zpool_map(void *pool, unsigned long handle,
+ enum zpool_mapmode mm)
+{
+ return zbud_map(pool, handle);
+}
+static void zbud_zpool_unmap(void *pool, unsigned long handle)
+{
+ zbud_unmap(pool, handle);
+}
+
+static u64 zbud_zpool_total_size(void *pool)
+{
+ return zbud_get_pool_size(pool) * PAGE_SIZE;
+}
+
+static struct zpool_driver zbud_zpool_driver = {
+ .type = "zbud",
+ .sleep_mapped = true,
+ .owner = THIS_MODULE,
+ .create = zbud_zpool_create,
+ .destroy = zbud_zpool_destroy,
+ .malloc = zbud_zpool_malloc,
+ .free = zbud_zpool_free,
+ .shrink = zbud_zpool_shrink,
+ .map = zbud_zpool_map,
+ .unmap = zbud_zpool_unmap,
+ .total_size = zbud_zpool_total_size,
+};
+
+MODULE_ALIAS("zpool-zbud");
+#endif /* CONFIG_ZPOOL */
+
static int __init init_zbud(void)
{
/* Make sure the zbud header will fit in one chunk */
--
2.23.0