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authorSebastian Ott <sebott@linux.vnet.ibm.com>2015-06-16 14:03:37 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2015-06-18 15:45:46 +0200
commit0c36b8ac7052eafed952ad3487ed8671dc9dc5f9 (patch)
treea21c1f42b85f175429f9da8365540f6f67e40a92 /arch/s390
parentd9a5c0c65bb93e6c0236c73fe560fe980c3a5d1c (diff)
downloadlinux-0c36b8ac7052eafed952ad3487ed8671dc9dc5f9.tar.gz
s390/setup: fix DMA_API_DEBUG warnings
Addresses from the usable space in [_ehead, _stext] lead to false
positives in DMA_API_DEBUG code (which will complain when an address
is in [_text, _etext]).

Avoid these warnings by not using that memory in case of
CONFIG_DMA_API_DEBUG=y.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/kernel/setup.c13
1 files changed, 9 insertions, 4 deletions
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index bdde603ee0ac..af4f41d52cde 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -640,19 +640,24 @@ static void __init check_initrd(void)
 }
 
 /*
- * Reserve all kernel text
+ * Reserve memory used for lowcore/command line/kernel image.
  */
 static void __init reserve_kernel(void)
 {
-	unsigned long start_pfn;
-	start_pfn = PFN_UP(__pa(&_end));
+	unsigned long start_pfn = PFN_UP(__pa(&_end));
 
+#ifdef CONFIG_DMA_API_DEBUG
 	/*
-	 * Reserve memory used for lowcore/command line/kernel image.
+	 * DMA_API_DEBUG code stumbles over addresses from the
+	 * range [_ehead, _stext]. Mark the memory as reserved
+	 * so it is not used for CONFIG_DMA_API_DEBUG=y.
 	 */
+	memblock_reserve(0, PFN_PHYS(start_pfn));
+#else
 	memblock_reserve(0, (unsigned long)_ehead);
 	memblock_reserve((unsigned long)_stext, PFN_PHYS(start_pfn)
 			 - (unsigned long)_stext);
+#endif
 }
 
 static void __init reserve_elfcorehdr(void)