78 строки
1.7 KiB
C
78 строки
1.7 KiB
C
/*
|
|
* Copyright IBM Corp. 2008
|
|
* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <asm/ipl.h>
|
|
#include <asm/sclp.h>
|
|
#include <asm/setup.h>
|
|
|
|
static inline int tprot(unsigned long addr)
|
|
{
|
|
int rc = -EFAULT;
|
|
|
|
asm volatile(
|
|
" tprot 0(%1),0\n"
|
|
"0: ipm %0\n"
|
|
" srl %0,28\n"
|
|
"1:\n"
|
|
EX_TABLE(0b,1b)
|
|
: "+d" (rc) : "a" (addr) : "cc");
|
|
return rc;
|
|
}
|
|
|
|
#define ADDR2G (1ULL << 31)
|
|
|
|
static void find_memory_chunks(struct mem_chunk chunk[])
|
|
{
|
|
unsigned long long memsize, rnmax, rzm;
|
|
unsigned long addr = 0, size;
|
|
int i = 0, type;
|
|
|
|
rzm = sclp_get_rzm();
|
|
rnmax = sclp_get_rnmax();
|
|
memsize = rzm * rnmax;
|
|
if (!rzm)
|
|
rzm = 1ULL << 17;
|
|
if (sizeof(long) == 4) {
|
|
rzm = min(ADDR2G, rzm);
|
|
memsize = memsize ? min(ADDR2G, memsize) : ADDR2G;
|
|
}
|
|
do {
|
|
size = 0;
|
|
type = tprot(addr);
|
|
do {
|
|
size += rzm;
|
|
if (memsize && addr + size >= memsize)
|
|
break;
|
|
} while (type == tprot(addr + size));
|
|
if (type == CHUNK_READ_WRITE || type == CHUNK_READ_ONLY) {
|
|
chunk[i].addr = addr;
|
|
chunk[i].size = size;
|
|
chunk[i].type = type;
|
|
i++;
|
|
}
|
|
addr += size;
|
|
} while (addr < memsize && i < MEMORY_CHUNKS);
|
|
}
|
|
|
|
void detect_memory_layout(struct mem_chunk chunk[])
|
|
{
|
|
unsigned long flags, cr0;
|
|
|
|
memset(chunk, 0, MEMORY_CHUNKS * sizeof(struct mem_chunk));
|
|
/* Disable IRQs, DAT and low address protection so tprot does the
|
|
* right thing and we don't get scheduled away with low address
|
|
* protection disabled.
|
|
*/
|
|
flags = __raw_local_irq_stnsm(0xf8);
|
|
__ctl_store(cr0, 0, 0);
|
|
__ctl_clear_bit(0, 28);
|
|
find_memory_chunks(chunk);
|
|
__ctl_load(cr0, 0, 0);
|
|
__raw_local_irq_ssm(flags);
|
|
}
|
|
EXPORT_SYMBOL(detect_memory_layout);
|