[mirror_ubuntu-zesty-kernel.git] / arch / s390 / kernel / mem_detect.c

/*
 * 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 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 = __arch_local_irq_stnsm(0xf8);
	__ctl_store(cr0, 0, 0);
	__ctl_clear_bit(0, 28);
	find_memory_chunks(chunk);
	__ctl_load(cr0, 0, 0);
	arch_local_irq_restore(flags);
}
EXPORT_SYMBOL(detect_memory_layout);
Commit	Line	Data
23d17421	1	/*
155af2f9 HJP	2	* Copyright IBM Corp. 2008, 2009
	3	*
	4	* Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
23d17421 HC	5	*/
	6
	7	#include <linux/kernel.h>
	8	#include <linux/module.h>
	9	#include <asm/ipl.h>
	10	#include <asm/sclp.h>
	11	#include <asm/setup.h>
	12
23d17421 HC	13	#define ADDR2G (1ULL << 31)
	14
	15	static void find_memory_chunks(struct mem_chunk chunk[])
	16	{
	17	unsigned long long memsize, rnmax, rzm;
	18	unsigned long addr = 0, size;
	19	int i = 0, type;
	20
	21	rzm = sclp_get_rzm();
	22	rnmax = sclp_get_rnmax();
	23	memsize = rzm * rnmax;
	24	if (!rzm)
	25	rzm = 1ULL << 17;
	26	if (sizeof(long) == 4) {
	27	rzm = min(ADDR2G, rzm);
	28	memsize = memsize ? min(ADDR2G, memsize) : ADDR2G;
	29	}
	30	do {
	31	size = 0;
	32	type = tprot(addr);
	33	do {
	34	size += rzm;
	35	if (memsize && addr + size >= memsize)
	36	break;
	37	} while (type == tprot(addr + size));
	38	if (type == CHUNK_READ_WRITE \|\| type == CHUNK_READ_ONLY) {
	39	chunk[i].addr = addr;
	40	chunk[i].size = size;
	41	chunk[i].type = type;
	42	i++;
	43	}
	44	addr += size;
	45	} while (addr < memsize && i < MEMORY_CHUNKS);
	46	}
	47
	48	void detect_memory_layout(struct mem_chunk chunk[])
	49	{
	50	unsigned long flags, cr0;
	51
	52	memset(chunk, 0, MEMORY_CHUNKS * sizeof(struct mem_chunk));
23d17421 HC	53	/* Disable IRQs, DAT and low address protection so tprot does the
	54	* right thing and we don't get scheduled away with low address
	55	* protection disabled.
	56	*/
df9ee292	57	flags = __arch_local_irq_stnsm(0xf8);
23d17421 HC	58	__ctl_store(cr0, 0, 0);
	59	__ctl_clear_bit(0, 28);
	60	find_memory_chunks(chunk);
	61	__ctl_load(cr0, 0, 0);
df9ee292	62	arch_local_irq_restore(flags);
23d17421 HC	63	}
23d17421 HC	64	EXPORT_SYMBOL(detect_memory_layout);