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/*
* Copyright IBM Corp. 2008, 2009
*
* 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>
#define ADDR2G (1ULL << 31)
static void find_memory_chunks(struct mem_chunk chunk[], unsigned long maxsize)
{
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;
}
if (maxsize)
memsize = memsize ? min((unsigned long)memsize, maxsize) : maxsize;
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) {
if (memsize && (addr + size > memsize))
size = memsize - addr;
chunk[i].addr = addr;
chunk[i].size = size;
chunk[i].type = type;
i++;
}
addr += size;
} while (addr < memsize && i < MEMORY_CHUNKS);
}
/**
* detect_memory_layout - fill mem_chunk array with memory layout data
* @chunk: mem_chunk array to be filled
* @maxsize: maximum address where memory detection should stop
*
* Fills the passed in memory chunk array with the memory layout of the
* machine. The array must have a size of at least MEMORY_CHUNKS and will
* be fully initialized afterwards.
* If the maxsize paramater has a value > 0 memory detection will stop at
* that address. It is guaranteed that all chunks have an ending address
* that is smaller than maxsize.
* If maxsize is 0 all memory will be detected.
*/
void detect_memory_layout(struct mem_chunk chunk[], unsigned long maxsize)
{
unsigned long flags, flags_dat, 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.
*/
local_irq_save(flags);
flags_dat = __arch_local_irq_stnsm(0xfb);
/*
* In case DAT was enabled, make sure chunk doesn't reside in vmalloc
* space. We have disabled DAT and any access to vmalloc area will
* cause an exception.
* If DAT was disabled we are called from early ipl code.
*/
if (test_bit(5, &flags_dat)) {
if (WARN_ON_ONCE(is_vmalloc_or_module_addr(chunk)))
goto out;
}
__ctl_store(cr0, 0, 0);
__ctl_clear_bit(0, 28);
find_memory_chunks(chunk, maxsize);
__ctl_load(cr0, 0, 0);
out:
__arch_local_irq_ssm(flags_dat);
local_irq_restore(flags);
}
EXPORT_SYMBOL(detect_memory_layout);
/*
* Create memory hole with given address and size.
*/
void create_mem_hole(struct mem_chunk mem_chunk[], unsigned long addr,
unsigned long size)
{
int i;
for (i = 0; i < MEMORY_CHUNKS; i++) {
struct mem_chunk *chunk = &mem_chunk[i];
if (chunk->size == 0)
continue;
if (addr > chunk->addr + chunk->size)
continue;
if (addr + size <= chunk->addr)
continue;
/* Split */
if ((addr > chunk->addr) &&
(addr + size < chunk->addr + chunk->size)) {
struct mem_chunk *new = chunk + 1;
memmove(new, chunk, (MEMORY_CHUNKS-i-1) * sizeof(*new));
new->addr = addr + size;
new->size = chunk->addr + chunk->size - new->addr;
chunk->size = addr - chunk->addr;
continue;
} else if ((addr <= chunk->addr) &&
(addr + size >= chunk->addr + chunk->size)) {
memset(chunk, 0 , sizeof(*chunk));
} else if (addr + size < chunk->addr + chunk->size) {
chunk->size = chunk->addr + chunk->size - addr - size;
chunk->addr = addr + size;
} else if (addr > chunk->addr) {
chunk->size = addr - chunk->addr;
}
}
}
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