[PATCH RFC 6/7] zram: Add recompression algorithm choice to Kconfig

[Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>]

Make (secondary) recompression algorithm selectable just like
we do it for the (primary) default one.

Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
 drivers/block/zram/Kconfig    | 40 +++++++++++++++++++++++++++++++++++
 drivers/block/zram/zram_drv.c |  2 +-
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/block/zram/Kconfig b/drivers/block/zram/Kconfig
index 81ae4b96ec1a..fc2d4d66c484 100644
--- a/drivers/block/zram/Kconfig
+++ b/drivers/block/zram/Kconfig
@@ -89,3 +89,43 @@ config ZRAM_MULTI_COMP
 
           echo TIMEOUT > /sys/block/zramX/idle
           echo SIZE > /sys/block/zramX/recompress
+
+choice
+	prompt "Default zram recompression algorithm"
+	default ZRAM_DEF_RECOMP_ZSTD
+	depends on ZRAM && ZRAM_MULTI_COMP
+
+config ZRAM_DEF_RECOMP_LZORLE
+	bool "lzo-rle"
+	depends on CRYPTO_LZO
+
+config ZRAM_DEF_RECOMP_ZSTD
+	bool "zstd"
+	depends on CRYPTO_ZSTD
+
+config ZRAM_DEF_RECOMP_LZ4
+	bool "lz4"
+	depends on CRYPTO_LZ4
+
+config ZRAM_DEF_RECOMP_LZO
+	bool "lzo"
+	depends on CRYPTO_LZO
+
+config ZRAM_DEF_RECOMP_LZ4HC
+	bool "lz4hc"
+	depends on CRYPTO_LZ4HC
+
+config ZRAM_DEF_RECOMP_842
+	bool "842"
+	depends on CRYPTO_842
+
+endchoice
+
+config ZRAM_DEF_RECOMP
+	string
+	default "lzo-rle" if ZRAM_DEF_RECOMP_LZORLE
+	default "zstd" if ZRAM_DEF_RECOMP_ZSTD
+	default "lz4" if ZRAM_DEF_RECOMP_LZ4
+	default "lzo" if ZRAM_DEF_RECOMP_LZO
+	default "lz4hc" if ZRAM_DEF_RECOMP_LZ4HC
+	default "842" if ZRAM_DEF_RECOMP_842
diff --git a/drivers/block/zram/zram_drv.c b/drivers/block/zram/zram_drv.c
index 386e49a13806..8ed41514b8f0 100644
--- a/drivers/block/zram/zram_drv.c
+++ b/drivers/block/zram/zram_drv.c
@@ -44,7 +44,7 @@ static int zram_major;
 static const char *default_comp_algs[ZRAM_MAX_ZCOMPS] = {
 	CONFIG_ZRAM_DEF_COMP,
 #ifdef CONFIG_ZRAM_MULTI_COMP
-	"zstd",
+	CONFIG_ZRAM_DEF_RECOMP,
 #endif
 };
 
-- 
2.37.2.789.g6183377224-goog