bzip2/lzma: make config machinery an arch configurable

Impact: Bug fix (we should not show this menu on irrelevant architectures)

Make the config machinery to drive the gzip/bzip2/lzma selection
dependent on the architecture advertising HAVE_KERNEL_* so that we
don't display this for architectures where it doesn't matter.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

2 files changed, 34 insertions, 21 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 862adb9bf0d4..7b66c34d0aae 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -39,6 +39,9 @@ config X86
         select HAVE_GENERIC_DMA_COHERENT if X86_32
         select HAVE_EFFICIENT_UNALIGNED_ACCESS
         select USER_STACKTRACE_SUPPORT
+        select HAVE_KERNEL_GZIP
+        select HAVE_KERNEL_BZIP2
+        select HAVE_KERNEL_LZMA
 
 config ARCH_DEFCONFIG
         string
diff --git a/init/Kconfig b/init/Kconfig
index df84625b1373..f9633c03cb12 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -101,10 +101,20 @@ config LOCALVERSION_AUTO
 
           which is done within the script "scripts/setlocalversion".)
 
+config HAVE_KERNEL_GZIP
+        bool
+
+config HAVE_KERNEL_BZIP2
+        bool
+
+config HAVE_KERNEL_LZMA
+        bool
+
 choice
-        prompt "Kernel compression mode"
-        default KERNEL_GZIP
-        help
+        prompt "Kernel compression mode"
+        default KERNEL_GZIP
+        depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA
+        help
           The linux kernel is a kind of self-extracting executable.
           Several compression algorithms are available, which differ
           in efficiency, compression and decompression speed.
@@ -123,34 +133,34 @@ choice
           If in doubt, select 'gzip'
 
 config KERNEL_GZIP
-       bool "Gzip"
-       help
-         The old and tried gzip compression. Its compression ratio is
-         the poorest among the 3 choices; however its speed (both
-         compression and decompression) is the fastest.
+        bool "Gzip"
+        depends on HAVE_KERNEL_GZIP
+        help
+          The old and tried gzip compression. Its compression ratio is
+          the poorest among the 3 choices; however its speed (both
+          compression and decompression) is the fastest.
 
 config KERNEL_BZIP2
         bool "Bzip2"
+        depends on HAVE_KERNEL_BZIP2
         help
           Its compression ratio and speed is intermediate.
-          Decompression speed is slowest among the 3.
-          The kernel size is about 10 per cent smaller with bzip2,
-          in comparison to gzip.
-          Bzip2 uses a large amount of memory. For modern kernels
-          you will need at least 8MB RAM or more for booting.
+          Decompression speed is slowest among the three.  The kernel
+          size is about 10% smaller with bzip2, in comparison to gzip.
+          Bzip2 uses a large amount of memory. For modern kernels you
+          will need at least 8MB RAM or more for booting.
 
 config KERNEL_LZMA
-       bool "LZMA"
-       help
-         The most recent compression algorithm.
-         Its ratio is best, decompression speed is between the other
-         2. Compression is slowest.
-         The kernel size is about 33 per cent smaller with lzma,
-         in comparison to gzip.
+        bool "LZMA"
+        depends on HAVE_KERNEL_LZMA
+        help
+          The most recent compression algorithm.
+          Its ratio is best, decompression speed is between the other
+          two. Compression is slowest.  The kernel size is about 33%
+          smaller with LZMA in comparison to gzip.
 
 endchoice
 
-
 config SWAP
         bool "Support for paging of anonymous memory (swap)"
         depends on MMU && BLOCK