From 3c8bb7aab9ad84bce7d81878fda64d631089a88d Mon Sep 17 00:00:00 2001
From: Nitin Gupta <ngupta@vflare.org>
Date: Fri, 18 Feb 2011 17:33:18 -0500
Subject: [PATCH] staging: Allow sharing xvmalloc for zram and zcache

Both zram and zcache use xvmalloc allocator. If xvmalloc
is compiled separately for both of them, we will get linker
error if they are both selected as "built-in". We can also
get linker error regarding missing xvmalloc symbols if zram
is not built.

So, we now compile xvmalloc separately and export its symbols
which are then used by both of zram and zcache.

Signed-off-by: Nitin Gupta <ngupta@vflare.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 drivers/staging/Makefile        | 1 +
 drivers/staging/zcache/Makefile | 4 +++-
 drivers/staging/zram/Kconfig    | 5 +++++
 drivers/staging/zram/Makefile   | 3 ++-
 drivers/staging/zram/xvmalloc.c | 8 ++++++++
 5 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/Makefile b/drivers/staging/Makefile
index 3519e5703d85..dcd47dba0e9a 100644
--- a/drivers/staging/Makefile
+++ b/drivers/staging/Makefile
@@ -45,6 +45,7 @@ obj-$(CONFIG_DX_SEP)            += sep/
 obj-$(CONFIG_IIO)		+= iio/
 obj-$(CONFIG_CS5535_GPIO)	+= cs5535_gpio/
 obj-$(CONFIG_ZRAM)		+= zram/
+obj-$(CONFIG_XVMALLOC)		+= zram/
 obj-$(CONFIG_ZCACHE)		+= zcache/
 obj-$(CONFIG_WLAGS49_H2)	+= wlags49_h2/
 obj-$(CONFIG_WLAGS49_H25)	+= wlags49_h25/
diff --git a/drivers/staging/zcache/Makefile b/drivers/staging/zcache/Makefile
index 7f64de4dff3b..f5ec64f94470 100644
--- a/drivers/staging/zcache/Makefile
+++ b/drivers/staging/zcache/Makefile
@@ -1 +1,3 @@
-obj-$(CONFIG_ZCACHE)	+=	zcache.o tmem.o
+zcache-y	:=	tmem.o
+
+obj-$(CONFIG_ZCACHE)	+=	zcache.o
diff --git a/drivers/staging/zram/Kconfig b/drivers/staging/zram/Kconfig
index 2f3b484ce5a4..3bec4dba3fe5 100644
--- a/drivers/staging/zram/Kconfig
+++ b/drivers/staging/zram/Kconfig
@@ -1,6 +1,11 @@
+config XVMALLOC
+	bool
+	default n
+
 config ZRAM
 	tristate "Compressed RAM block device support"
 	depends on BLOCK && SYSFS
+	select XVMALLOC
 	select LZO_COMPRESS
 	select LZO_DECOMPRESS
 	default n
diff --git a/drivers/staging/zram/Makefile b/drivers/staging/zram/Makefile
index b1709c57f636..2a6d3213a756 100644
--- a/drivers/staging/zram/Makefile
+++ b/drivers/staging/zram/Makefile
@@ -1,3 +1,4 @@
-zram-y	:=	zram_drv.o zram_sysfs.o xvmalloc.o
+zram-y	:=	zram_drv.o zram_sysfs.o
 
 obj-$(CONFIG_ZRAM)	+=	zram.o
+obj-$(CONFIG_XVMALLOC)	+=	xvmalloc.o
\ No newline at end of file
diff --git a/drivers/staging/zram/xvmalloc.c b/drivers/staging/zram/xvmalloc.c
index ae0623a65ab9..1f9c5082b6d5 100644
--- a/drivers/staging/zram/xvmalloc.c
+++ b/drivers/staging/zram/xvmalloc.c
@@ -14,6 +14,8 @@
 #define DEBUG
 #endif
 
+#include <linux/module.h>
+#include <linux/kernel.h>
 #include <linux/bitops.h>
 #include <linux/errno.h>
 #include <linux/highmem.h>
@@ -315,11 +317,13 @@ struct xv_pool *xv_create_pool(void)
 
 	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.
@@ -408,6 +412,7 @@ int xv_malloc(struct xv_pool *pool, u32 size, struct page **page,
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(xv_malloc);
 
 /*
  * Free block identified with <page, offset>
@@ -484,6 +489,7 @@ void xv_free(struct xv_pool *pool, struct page *page, u32 offset)
 	put_ptr_atomic(page_start, KM_USER0);
 	spin_unlock(&pool->lock);
 }
+EXPORT_SYMBOL_GPL(xv_free);
 
 u32 xv_get_object_size(void *obj)
 {
@@ -492,6 +498,7 @@ u32 xv_get_object_size(void *obj)
 	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)
@@ -500,3 +507,4 @@ u64 xv_get_total_size_bytes(struct xv_pool *pool)
 {
 	return pool->total_pages << PAGE_SHIFT;
 }
+EXPORT_SYMBOL_GPL(xv_get_total_size_bytes);
-- 
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