x86: Fix hwpoison code related build failure on 32-bit NUMAQ

This build failure triggers:

 In file included from include/linux/suspend.h:8,
                 from arch/x86/kernel/asm-offsets_32.c:11,
                 from arch/x86/kernel/asm-offsets.c:2:
 include/linux/mm.h:503:2: error: #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS

Because due to the hwpoison page flag we ran out of page
flags on 32-bit.

Dont turn on hwpoison on 32-bit NUMA (it's rare in any
case).

Also clean up the Kconfig dependencies in the generic MM
code by introducing ARCH_SUPPORTS_MEMORY_FAILURE.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 14 insertions, 1 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 93698794aa3a..8da93745c087 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -432,6 +432,17 @@ config X86_NUMAQ
           of Flat Logical.  You will need a new lynxer.elf file to flash your
           firmware with - send email to <Martin.Bligh@us.ibm.com>.
 
+config X86_SUPPORTS_MEMORY_FAILURE
+        bool
+        # MCE code calls memory_failure():
+        depends on X86_MCE
+        # On 32-bit this adds too big of NODES_SHIFT and we run out of page flags:
+        depends on !X86_NUMAQ
+        # On 32-bit SPARSEMEM adds too big of SECTIONS_WIDTH:
+        depends on X86_64 || !SPARSEMEM
+        select ARCH_SUPPORTS_MEMORY_FAILURE
+        default y
+
 config X86_VISWS
         bool "SGI 320/540 (Visual Workstation)"
         depends on X86_32 && PCI && X86_MPPARSE && PCI_GODIRECT
diff --git a/mm/Kconfig b/mm/Kconfig
index 247760729593..edd300aca173 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -244,10 +244,12 @@ config DEFAULT_MMAP_MIN_ADDR
           This value can be changed after boot using the
           /proc/sys/vm/mmap_min_addr tunable.
 
+config ARCH_SUPPORTS_MEMORY_FAILURE
+        bool
 
 config MEMORY_FAILURE
         depends on MMU
-        depends on X86_MCE
+        depends on ARCH_SUPPORTS_MEMORY_FAILURE
         bool "Enable recovery from hardware memory errors"
         help
           Enables code to recover from some memory failures on systems