Re: [patch -mm] Make check_signature() depend on CONFIG_HAS_IOMEM

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 28 Jun 2007 20:47:33 +0200 (CEST)
Geert Uytterhoeven <geert@linux-m68k.org> wrote:

> > > Apart from many Kconfig dependencies on HAS_IOMEM, CONFIG_HAS_IOMEM is
> > > further only used to control the build of lib/iomap_copy.c, which
> > > doesn't use readb() and friends, but the __raw*() operations.
> > > 
> > 
> > Well this is fun.
> > 
> > How to fix? Should we add a new CONFIG_HAS_IO?  (IOPORTS?)
> 
> There already exists a CONFIG_HAS_IOPORT :-) (for ISA/PCI-style I/O port
> access).
> 
> Just make check_signature() depend on ISA || PCI (and maybe || X86_32).
> According to its comment, it's used to `find BIOS signatures', which is
> a legacy PC thing. Please don't pollute non-legacy architectures with it ;-)

I merged the below and will await the next explosion.


From: Andrew Morton <akpm@linux-foundation.org>

check_signature() needs readb() but with some setups (s390, m68k allmodconfig)
there is no implementation of readb.  This causes build errors with
-Werror-implicit-function-declaration.

So make check_signature.o dependent upon ISA||PCI.

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/Kconfig  |    5 ++++-
 lib/Makefile |    3 ++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff -puN lib/Kconfig~check_signature-needs-readb lib/Kconfig
--- a/lib/Kconfig~check_signature-needs-readb
+++ a/lib/Kconfig
@@ -110,11 +110,14 @@ config TEXTSEARCH_FSM
 	tristate
 
 #
-# plist support is select#ed if needed
+# plist support is selected if needed
 #
 config PLIST
 	boolean
 
+config CHECK_SIGNATURE
+	def_bool ISA || PCI
+
 config HAS_IOMEM
 	boolean
 	depends on !NO_IOMEM
diff -puN lib/Makefile~check_signature-needs-readb lib/Makefile
--- a/lib/Makefile~check_signature-needs-readb
+++ a/lib/Makefile
@@ -13,7 +13,7 @@ lib-$(CONFIG_SMP) += cpumask.o
 lib-y	+= kobject.o kref.o kobject_uevent.o klist.o
 
 obj-y += div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \
-	 bust_spinlocks.o hexdump.o check_signature.o
+	 bust_spinlocks.o hexdump.o
 
 ifeq ($(CONFIG_DEBUG_KOBJECT),y)
 CFLAGS_kobject.o += -DDEBUG
@@ -33,6 +33,7 @@ obj-$(CONFIG_LOCK_KERNEL) += kernel_lock
 obj-$(CONFIG_PLIST) += plist.o
 obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o
 obj-$(CONFIG_DEBUG_LIST) += list_debug.o
+obj-$(CONFIG_CHECK_SIGNATURE) += check_signature.o
 
 ifneq ($(CONFIG_HAVE_DEC_LOCK),y)
   lib-y += dec_and_lock.o
_