diff --git a/debian/changelog b/debian/changelog
index a8ad6f120..614aac0ab 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,10 @@
+linux-2.6 (2.6.39~rc4-1~experimental.2) UNRELEASED; urgency=low
+
+  [ Ben Hutchings ]
+  * [powerpc] kexec: Fix build failure on 32-bit SMP
+
+ -- Ben Hutchings <ben@decadent.org.uk>  Mon, 25 Apr 2011 02:08:20 +0100
+
 linux-2.6 (2.6.39~rc4-1~experimental.1) experimental; urgency=low
 
   * New upstream release candidate
diff --git a/debian/patches/bugfix/powerpc/powerpc-kexec-Fix-build-failure-on-32-bit-SMP.patch b/debian/patches/bugfix/powerpc/powerpc-kexec-Fix-build-failure-on-32-bit-SMP.patch
new file mode 100644
index 000000000..73c04a086
--- /dev/null
+++ b/debian/patches/bugfix/powerpc/powerpc-kexec-Fix-build-failure-on-32-bit-SMP.patch
@@ -0,0 +1,100 @@
+Subject: [PATCH] powerpc/kexec: Fix build failure on 32-bit SMP
+From: Ben Hutchings <ben@decadent.org.uk>
+Date: Mon, 25 Apr 2011 02:04:31 +0100
+
+Commit b987812b3fcaf70fdf0037589e5d2f5f2453e6ce left
+crash_kexec_wait_realmode() undefined for UP.
+
+Commit 7c7a81b53e581d727d069cc45df5510516faac31 defined it for UP but
+left it undefined for 32-bit SMP.
+
+Seems like people are getting confused by nested #ifdef's, so move the
+definitions of crash_kexec_wait_realmode() after the #ifdef CONFIG_SMP
+section.
+
+Compile-tested with 32-bit UP, 32-bit SMP and 64-bit SMP configurations.
+
+Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
+---
+--- a/arch/powerpc/kernel/crash.c
++++ b/arch/powerpc/kernel/crash.c
+@@ -162,34 +162,6 @@
+ 	/* Leave the IPI callback set */
+ }
+ 
+-/* wait for all the CPUs to hit real mode but timeout if they don't come in */
+-#ifdef CONFIG_PPC_STD_MMU_64
+-static void crash_kexec_wait_realmode(int cpu)
+-{
+-	unsigned int msecs;
+-	int i;
+-
+-	msecs = 10000;
+-	for (i=0; i < NR_CPUS && msecs > 0; i++) {
+-		if (i == cpu)
+-			continue;
+-
+-		while (paca[i].kexec_state < KEXEC_STATE_REAL_MODE) {
+-			barrier();
+-			if (!cpu_possible(i)) {
+-				break;
+-			}
+-			if (!cpu_online(i)) {
+-				break;
+-			}
+-			msecs--;
+-			mdelay(1);
+-		}
+-	}
+-	mb();
+-}
+-#endif	/* CONFIG_PPC_STD_MMU_64 */
+-
+ /*
+  * This function will be called by secondary cpus or by kexec cpu
+  * if soft-reset is activated to stop some CPUs.
+@@ -234,7 +206,6 @@
+ }
+ 
+ #else	/* ! CONFIG_SMP */
+-static inline void crash_kexec_wait_realmode(int cpu) {}
+ 
+ static void crash_kexec_prepare_cpus(int cpu)
+ {
+@@ -257,6 +228,36 @@
+ }
+ #endif	/* CONFIG_SMP */
+ 
++/* wait for all the CPUs to hit real mode but timeout if they don't come in */
++#if defined(CONFIG_SMP) && defined(CONFIG_PPC_STD_MMU_64)
++static void crash_kexec_wait_realmode(int cpu)
++{
++	unsigned int msecs;
++	int i;
++
++	msecs = 10000;
++	for (i=0; i < NR_CPUS && msecs > 0; i++) {
++		if (i == cpu)
++			continue;
++
++		while (paca[i].kexec_state < KEXEC_STATE_REAL_MODE) {
++			barrier();
++			if (!cpu_possible(i)) {
++				break;
++			}
++			if (!cpu_online(i)) {
++				break;
++			}
++			msecs--;
++			mdelay(1);
++		}
++	}
++	mb();
++}
++#else
++static inline void crash_kexec_wait_realmode(int cpu) {}
++#endif	/* CONFIG_SMP && CONFIG_PPC_STD_MMU_64 */
++
+ /*
+  * Register a function to be called on shutdown.  Only use this if you
+  * can't reset your device in the second kernel.