[S390] Memory detection fixes.

From: Martin Schwidefsky
Date: Mon Dec 04 2006 - 09:58:03 EST

From: Heiko Carstens <heiko.carstens@xxxxxxxxxx>

[S390] Memory detection fixes.

VMALLOC_END on 31bit should be 0x8000000UL instead of 0x7fffffffL.
The page mask which is used to make sure memory_end is on 4MB/2MB
boundary is wrong and not needed. Therefore remove it.
Make sure a vmalloc area does also exist and work on (future)
machines with 4TB and more memory.

Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
---

arch/s390/kernel/head31.S | 3 --
arch/s390/kernel/head64.S | 4 ---
arch/s390/kernel/setup.c | 49 +++++++++++++++++++++++++++++----------------
include/asm-s390/pgtable.h | 15 +++++++++++--
4 files changed, 44 insertions(+), 27 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 2006-12-04 14:50:53.000000000 +0100
+++ linux-2.6-patched/arch/s390/kernel/head31.S 2006-12-04 14:51:01.000000000 +0100
@@ -177,8 +177,6 @@ startup_continue:
st %r0,4(%r3) # store size of chunk
st %r6,8(%r3) # store type of chunk
la %r3,12(%r3)
- l %r4,.Lmemsize-.LPG1(%r13) # address of variable memory_size
- st %r5,0(%r4) # store last end to memory size
ahi %r10,-1 # update chunk number
.Lchkloop:
lr %r6,%r7 # set access code to last cc
@@ -293,7 +291,6 @@ startup_continue:
.Lpcmvpg:.long 0x00080000,0x80000000 + .Lchkmvpg
.Lpcidte:.long 0x00080000,0x80000000 + .Lchkidte
.Lpcdiag9c:.long 0x00080000,0x80000000 + .Lchkdiag9c
-.Lmemsize:.long memory_size
.Lmchunk:.long memory_chunk
.Lmflags:.long machine_flags
.Lbss_bgn: .long __bss_start
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 2006-12-04 14:50:56.000000000 +0100
+++ linux-2.6-patched/arch/s390/kernel/head64.S 2006-12-04 14:51:01.000000000 +0100
@@ -81,8 +81,6 @@ startup_continue:
aghi %r1,1 # size is one more than end
larl %r2,memory_chunk
stg %r1,8(%r2) # store size of chunk
- larl %r2,memory_size
- stg %r1,0(%r2) # set memory size
j .Ldonemem

.Lslowmemdetect:
@@ -188,8 +186,6 @@ startup_continue:
stg %r0,8(%r3) # store size of chunk
st %r6,20(%r3) # store type of chunk
la %r3,24(%r3)
- larl %r8,memory_size
- stg %r5,0(%r8) # store memory size
ahi %r10,-1 # update chunk number
.Lchkloop:
lr %r6,%r7 # set access code to last cc
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 2006-12-04 14:50:53.000000000 +0100
+++ linux-2.6-patched/arch/s390/kernel/setup.c 2006-12-04 14:51:01.000000000 +0100
@@ -62,7 +62,6 @@ EXPORT_SYMBOL_GPL(uaccess);
unsigned int console_mode = 0;
unsigned int console_devno = -1;
unsigned int console_irq = -1;
-unsigned long memory_size = 0;
unsigned long machine_flags = 0;

struct mem_chunk memory_chunk[MEMORY_CHUNKS];
@@ -486,6 +485,37 @@ setup_resources(void)
}
}

+static void __init setup_memory_end(void)
+{
+ unsigned long real_size, memory_size;
+ unsigned long max_mem, max_phys;
+ int i;
+
+ memory_size = real_size = 0;
+ max_phys = VMALLOC_END - VMALLOC_MIN_SIZE;
+ memory_end &= PAGE_MASK;
+
+ max_mem = memory_end ? min(max_phys, memory_end) : max_phys;
+
+ for (i = 0; i < MEMORY_CHUNKS; i++) {
+ struct mem_chunk *chunk = &memory_chunk[i];
+
+ real_size = max(real_size, chunk->addr + chunk->size);
+ if (chunk->addr >= max_mem) {
+ memset(chunk, 0, sizeof(*chunk));
+ continue;
+ }
+ if (chunk->addr + chunk->size > max_mem)
+ chunk->size = max_mem - chunk->addr;
+ memory_size = max(memory_size, chunk->addr + chunk->size);
+ }
+ if (!memory_end)
+ memory_end = memory_size;
+ if (real_size > memory_end)
+ printk("More memory detected than supported. Unused: %luk\n",
+ (real_size - memory_end) >> 10);
+}
+
static void __init
setup_memory(void)
{
@@ -642,8 +672,6 @@ setup_arch(char **cmdline_p)
init_mm.end_data = (unsigned long) &_edata;
init_mm.brk = (unsigned long) &_end;

- memory_end = memory_size;
-
if (MACHINE_HAS_MVCOS)
memcpy(&uaccess, &uaccess_mvcos, sizeof(uaccess));
else
@@ -651,20 +679,7 @@ setup_arch(char **cmdline_p)

parse_early_param();

-#ifndef CONFIG_64BIT
- memory_end &= ~0x400000UL;
-
- /*
- * We need some free virtual space to be able to do vmalloc.
- * On a machine with 2GB memory we make sure that we have at
- * least 128 MB free space for vmalloc.
- */
- if (memory_end > 1920*1024*1024)
- memory_end = 1920*1024*1024;
-#else /* CONFIG_64BIT */
- memory_end &= ~0x200000UL;
-#endif /* CONFIG_64BIT */
-
+ setup_memory_end();
setup_memory();
setup_resources();
setup_lowcore();
diff -urpN linux-2.6/include/asm-s390/pgtable.h linux-2.6-patched/include/asm-s390/pgtable.h
--- linux-2.6/include/asm-s390/pgtable.h 2006-11-29 22:57:37.000000000 +0100
+++ linux-2.6-patched/include/asm-s390/pgtable.h 2006-12-04 14:51:01.000000000 +0100
@@ -110,13 +110,22 @@ extern char empty_zero_page[PAGE_SIZE];
#define VMALLOC_OFFSET (8*1024*1024)
#define VMALLOC_START (((unsigned long) high_memory + VMALLOC_OFFSET) \
& ~(VMALLOC_OFFSET-1))
+
+/*
+ * We need some free virtual space to be able to do vmalloc.
+ * VMALLOC_MIN_SIZE defines the minimum size of the vmalloc
+ * area. On a machine with 2GB memory we make sure that we
+ * have at least 128MB free space for vmalloc. On a machine
+ * with 4TB we make sure we have at least 1GB.
+ */
#ifndef __s390x__
-# define VMALLOC_END (0x7fffffffL)
+#define VMALLOC_MIN_SIZE 0x8000000UL
+#define VMALLOC_END 0x80000000UL
#else /* __s390x__ */
-# define VMALLOC_END (0x40000000000L)
+#define VMALLOC_MIN_SIZE 0x40000000UL
+#define VMALLOC_END 0x40000000000UL
#endif /* __s390x__ */

-
/*
* A 31 bit pagetable entry of S390 has following format:
* | PFRA | | OS |
-
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