[patch] s390: initrd vs. bootmem bitmap.
From: Martin Schwidefsky
Date: Mon Aug 07 2006 - 11:05:27 EST
From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
[S390] initrd vs. bootmem bitmap.
Move initrd if the bitmap of the bootmem allocator would overwrite it.
In addition this patch sets the default size and address of the initrd to 0.
Therefore all boot loaders must set the initrd size and address correctly.
This is especially relevant for ftp boot via HMC/SE, where this change
requires a special patch file entry in the .ins file which sets these two
values contained at address 0x10408 and 0x10410.
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---
arch/s390/kernel/head.S | 10 ++++++----
arch/s390/kernel/head31.S | 4 ++--
arch/s390/kernel/head64.S | 4 ++--
arch/s390/kernel/setup.c | 40 +++++++++++++++++++++++++++++++++++++---
include/asm-s390/setup.h | 2 --
5 files changed, 47 insertions(+), 13 deletions(-)
diff -urpN linux-2.6/arch/s390/kernel/head31.S linux-2.6-patched/arch/s390/kernel/head31.S
--- linux-2.6/arch/s390/kernel/head31.S 2006-08-07 14:14:23.000000000 +0200
+++ linux-2.6-patched/arch/s390/kernel/head31.S 2006-08-07 14:14:47.000000000 +0200
@@ -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 -urpN linux-2.6/arch/s390/kernel/head64.S linux-2.6-patched/arch/s390/kernel/head64.S
--- linux-2.6/arch/s390/kernel/head64.S 2006-08-07 14:14:23.000000000 +0200
+++ linux-2.6-patched/arch/s390/kernel/head64.S 2006-08-07 14:14:47.000000000 +0200
@@ -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 -urpN linux-2.6/arch/s390/kernel/head.S linux-2.6-patched/arch/s390/kernel/head.S
--- linux-2.6/arch/s390/kernel/head.S 2006-08-07 14:14:23.000000000 +0200
+++ linux-2.6-patched/arch/s390/kernel/head.S 2006-08-07 14:14:47.000000000 +0200
@@ -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 -urpN linux-2.6/arch/s390/kernel/setup.c linux-2.6-patched/arch/s390/kernel/setup.c
--- linux-2.6/arch/s390/kernel/setup.c 2006-08-07 14:14:23.000000000 +0200
+++ linux-2.6-patched/arch/s390/kernel/setup.c 2006-08-07 14:14:47.000000000 +0200
@@ -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 +502,46 @@ 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 = PFN_ALIGN((end_pfn - start_pfn) >> 3);
+
+ 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 +593,7 @@ 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;
diff -urpN linux-2.6/include/asm-s390/setup.h linux-2.6-patched/include/asm-s390/setup.h
--- linux-2.6/include/asm-s390/setup.h 2006-08-07 14:14:35.000000000 +0200
+++ linux-2.6-patched/include/asm-s390/setup.h 2006-08-07 14:14:47.000000000 +0200
@@ -14,8 +14,6 @@
#define PARMAREA 0x10400
#define COMMAND_LINE_SIZE 896
-#define RAMDISK_ORIGIN 0x800000
-#define RAMDISK_SIZE 0x800000
#define MEMORY_CHUNKS 16 /* max 0x7fff */
#define IPL_PARMBLOCK_ORIGIN 0x2000
-
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