4 files changed, 48 insertions, 11 deletions

diff --git a/arch/s390/kernel/head.S b/arch/s390/kernel/head.S
index adad8863ee2f..a6e9bdb53591 100644
--- a/arch/s390/kernel/head.S
+++ b/arch/s390/kernel/head.S
@@ -272,7 +272,7 @@ iplstart:
 # load parameter file from ipl device
 #
 .Lagain1:
-        l     %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # ramdisk loc. is temp
+        l     %r2,.Linitrd                     # ramdisk loc. is temp
         bas   %r14,.Lloader                    # load parameter file
         ltr   %r2,%r2                          # got anything ?
         bz    .Lnopf
@@ -280,7 +280,7 @@ iplstart:
         bnh   .Lnotrunc
         la    %r2,895
 .Lnotrunc:
-        l     %r4,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
+        l     %r4,.Linitrd
         clc   0(3,%r4),.L_hdr                  # if it is HDRx
         bz    .Lagain1                         # skip dataset header
         clc   0(3,%r4),.L_eof                  # if it is EOFx
@@ -323,14 +323,15 @@ iplstart:
 # load ramdisk from ipl device
 #       
 .Lagain2:
-        l     %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # addr of ramdisk
+        l     %r2,.Linitrd                     # addr of ramdisk
+        st    %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
         bas   %r14,.Lloader                    # load ramdisk
         st    %r2,INITRD_SIZE+ARCH_OFFSET-PARMAREA(%r12) # store size of ramdisk
         ltr   %r2,%r2
         bnz   .Lrdcont
         st    %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12) # no ramdisk found
 .Lrdcont:
-        l     %r2,INITRD_START+ARCH_OFFSET-PARMAREA(%r12)
+        l     %r2,.Linitrd
 
         clc   0(3,%r2),.L_hdr                  # skip HDRx and EOFx 
         bz    .Lagain2
@@ -379,6 +380,7 @@ iplstart:
         l     %r1,.Lstartup
         br    %r1
 
+.Linitrd:.long _end + 0x400000                 # default address of initrd
 .Lparm: .long  PARMAREA
 .Lstartup: .long startup
 .Lcvtab:.long  _ebcasc                         # ebcdic to ascii table
diff --git a/arch/s390/kernel/head31.S b/arch/s390/kernel/head31.S
index a4dc61f3285e..0e46077d7140 100644
--- a/arch/s390/kernel/head31.S
+++ b/arch/s390/kernel/head31.S
@@ -26,8 +26,8 @@ startup:basr	%r13,0			# get base
 #
         .org    PARMAREA
         .long   0,0                     # IPL_DEVICE
-        .long   0,RAMDISK_ORIGIN        # INITRD_START
-        .long   0,RAMDISK_SIZE          # INITRD_SIZE
+        .long   0,0                     # INITRD_START
+        .long   0,0                     # INITRD_SIZE
 
         .org    COMMAND_LINE
         .byte   "root=/dev/ram0 ro"
diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S
index 9d80c5b1ef95..3e0341acd04e 100644
--- a/arch/s390/kernel/head64.S
+++ b/arch/s390/kernel/head64.S
@@ -26,8 +26,8 @@ startup:basr  %r13,0			 # get base
 #
         .org   PARMAREA
         .quad  0                        # IPL_DEVICE
-        .quad  RAMDISK_ORIGIN           # INITRD_START
-        .quad  RAMDISK_SIZE             # INITRD_SIZE
+        .quad  0                        # INITRD_START
+        .quad  0                        # INITRD_SIZE
 
         .org   COMMAND_LINE
         .byte  "root=/dev/ram0 ro"
diff --git a/arch/s390/kernel/setup.c b/arch/s390/kernel/setup.c
index c902f059c7aa..89051e8a5d8d 100644
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -37,6 +37,7 @@
 #include <linux/kernel_stat.h>
 #include <linux/device.h>
 #include <linux/notifier.h>
+#include <linux/pfn.h>
 
 #include <asm/uaccess.h>
 #include <asm/system.h>
@@ -501,13 +502,47 @@ setup_memory(void)
          * partially used pages are not usable - thus
          * we are rounding upwards:
          */
-        start_pfn = (__pa(&_end) + PAGE_SIZE - 1) >> PAGE_SHIFT;
-        end_pfn = max_pfn = memory_end >> PAGE_SHIFT;
+        start_pfn = PFN_UP(__pa(&_end));
+        end_pfn = max_pfn = PFN_DOWN(memory_end);
 
         /* Initialize storage key for kernel pages */
         for (init_pfn = 0 ; init_pfn < start_pfn; init_pfn++)
                 page_set_storage_key(init_pfn << PAGE_SHIFT, PAGE_DEFAULT_KEY);
 
+#ifdef CONFIG_BLK_DEV_INITRD
+        /*
+         * Move the initrd in case the bitmap of the bootmem allocater
+         * would overwrite it.
+         */
+
+        if (INITRD_START && INITRD_SIZE) {
+                unsigned long bmap_size;
+                unsigned long start;
+
+                bmap_size = bootmem_bootmap_pages(end_pfn - start_pfn + 1);
+                bmap_size = PFN_PHYS(bmap_size);
+
+                if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
+                        start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;
+
+                        if (start + INITRD_SIZE > memory_end) {
+                                printk("initrd extends beyond end of memory "
+                                       "(0x%08lx > 0x%08lx)\n"
+                                       "disabling initrd\n",
+                                       start + INITRD_SIZE, memory_end);
+                                INITRD_START = INITRD_SIZE = 0;
+                        } else {
+                                printk("Moving initrd (0x%08lx -> 0x%08lx, "
+                                       "size: %ld)\n",
+                                       INITRD_START, start, INITRD_SIZE);
+                                memmove((void *) start, (void *) INITRD_START,
+                                        INITRD_SIZE);
+                                INITRD_START = start;
+                        }
+                }
+        }
+#endif
+
         /*
          * Initialize the boot-time allocator (with low memory only):
          */
@@ -559,7 +594,7 @@ setup_memory(void)
         reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size);
 
 #ifdef CONFIG_BLK_DEV_INITRD
-        if (INITRD_START) {
+        if (INITRD_START && INITRD_SIZE) {
                 if (INITRD_START + INITRD_SIZE <= memory_end) {
                         reserve_bootmem(INITRD_START, INITRD_SIZE);
                         initrd_start = INITRD_START;