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Commit e0bc2495 authored by Heiko Carstens's avatar Heiko Carstens
Browse files

[S390] Add support for memory hot-add via sclp.



Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 421c175c
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+308 −8
Original line number Diff line number Diff line
@@ -11,6 +11,9 @@
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/mmzone.h>
#include <linux/memory.h>
#include <asm/chpid.h>
#include <asm/sclp.h>
#include "sclp.h"
@@ -43,6 +46,8 @@ static int __initdata early_read_info_sccb_valid;

u64 sclp_facilities;
static u8 sclp_fac84;
static unsigned long long rzm;
static unsigned long long rnmax;

static int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb)
{
@@ -106,14 +111,10 @@ unsigned long long __init sclp_memory_detect(void)
	if (!early_read_info_sccb_valid)
		return 0;
	sccb = &early_read_info_sccb;
	if (sccb->rnsize)
		memsize = sccb->rnsize << 20;
	else
		memsize = sccb->rnsize2 << 20;
	if (sccb->rnmax)
		memsize *= sccb->rnmax;
	else
		memsize *= sccb->rnmax2;
	rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
	rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
	rzm <<= 20;
	memsize = rzm * rnmax;
	return memsize;
}

@@ -278,6 +279,305 @@ int sclp_cpu_deconfigure(u8 cpu)
	return do_cpu_configure(SCLP_CMDW_DECONFIGURE_CPU | cpu << 8);
}

#ifdef CONFIG_MEMORY_HOTPLUG

static DEFINE_MUTEX(sclp_mem_mutex);
static LIST_HEAD(sclp_mem_list);
static u8 sclp_max_storage_id;
static unsigned long sclp_storage_ids[256 / BITS_PER_LONG];

struct memory_increment {
	struct list_head list;
	u16 rn;
	int standby;
	int usecount;
};

struct assign_storage_sccb {
	struct sccb_header header;
	u16 rn;
} __packed;

static unsigned long long rn2addr(u16 rn)
{
	return (unsigned long long) (rn - 1) * rzm;
}

static int do_assign_storage(sclp_cmdw_t cmd, u16 rn)
{
	struct assign_storage_sccb *sccb;
	int rc;

	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!sccb)
		return -ENOMEM;
	sccb->header.length = PAGE_SIZE;
	sccb->rn = rn;
	rc = do_sync_request(cmd, sccb);
	if (rc)
		goto out;
	switch (sccb->header.response_code) {
	case 0x0020:
	case 0x0120:
		break;
	default:
		rc = -EIO;
		break;
	}
out:
	free_page((unsigned long) sccb);
	return rc;
}

static int sclp_assign_storage(u16 rn)
{
	return do_assign_storage(0x000d0001, rn);
}

static int sclp_unassign_storage(u16 rn)
{
	return do_assign_storage(0x000c0001, rn);
}

struct attach_storage_sccb {
	struct sccb_header header;
	u16 :16;
	u16 assigned;
	u32 :32;
	u32 entries[0];
} __packed;

static int sclp_attach_storage(u8 id)
{
	struct attach_storage_sccb *sccb;
	int rc;
	int i;

	sccb = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
	if (!sccb)
		return -ENOMEM;
	sccb->header.length = PAGE_SIZE;
	rc = do_sync_request(0x00080001 | id << 8, sccb);
	if (rc)
		goto out;
	switch (sccb->header.response_code) {
	case 0x0020:
		set_bit(id, sclp_storage_ids);
		for (i = 0; i < sccb->assigned; i++)
			sclp_unassign_storage(sccb->entries[i] >> 16);
		break;
	default:
		rc = -EIO;
		break;
	}
out:
	free_page((unsigned long) sccb);
	return rc;
}

static int sclp_mem_change_state(unsigned long start, unsigned long size,
				 int online)
{
	struct memory_increment *incr;
	unsigned long long istart;
	int rc = 0;

	list_for_each_entry(incr, &sclp_mem_list, list) {
		istart = rn2addr(incr->rn);
		if (start + size - 1 < istart)
			break;
		if (start > istart + rzm - 1)
			continue;
		if (online) {
			if (incr->usecount++)
				continue;
			/*
			 * Don't break the loop if one assign fails. Loop may
			 * be walked again on CANCEL and we can't save
			 * information if state changed before or not.
			 * So continue and increase usecount for all increments.
			 */
			rc |= sclp_assign_storage(incr->rn);
		} else {
			if (--incr->usecount)
				continue;
			sclp_unassign_storage(incr->rn);
		}
	}
	return rc ? -EIO : 0;
}

static int sclp_mem_notifier(struct notifier_block *nb,
			     unsigned long action, void *data)
{
	unsigned long start, size;
	struct memory_notify *arg;
	unsigned char id;
	int rc = 0;

	arg = data;
	start = arg->start_pfn << PAGE_SHIFT;
	size = arg->nr_pages << PAGE_SHIFT;
	mutex_lock(&sclp_mem_mutex);
	for (id = 0; id <= sclp_max_storage_id; id++)
		if (!test_bit(id, sclp_storage_ids))
			sclp_attach_storage(id);
	switch (action) {
	case MEM_ONLINE:
		break;
	case MEM_GOING_ONLINE:
		rc = sclp_mem_change_state(start, size, 1);
		break;
	case MEM_CANCEL_ONLINE:
		sclp_mem_change_state(start, size, 0);
		break;
	default:
		rc = -EINVAL;
		break;
	}
	mutex_unlock(&sclp_mem_mutex);
	return rc ? NOTIFY_BAD : NOTIFY_OK;
}

static struct notifier_block sclp_mem_nb = {
	.notifier_call = sclp_mem_notifier,
};

static void __init add_memory_merged(u16 rn)
{
	static u16 first_rn, num;
	unsigned long long start, size;

	if (rn && first_rn && (first_rn + num == rn)) {
		num++;
		return;
	}
	if (!first_rn)
		goto skip_add;
	start = rn2addr(first_rn);
	size = (unsigned long long ) num * rzm;
	if (start >= VMEM_MAX_PHYS)
		goto skip_add;
	if (start + size > VMEM_MAX_PHYS)
		size = VMEM_MAX_PHYS - start;
	add_memory(0, start, size);
skip_add:
	first_rn = rn;
	num = 1;
}

static void __init sclp_add_standby_memory(void)
{
	struct memory_increment *incr;

	list_for_each_entry(incr, &sclp_mem_list, list)
		if (incr->standby)
			add_memory_merged(incr->rn);
	add_memory_merged(0);
}

static void __init insert_increment(u16 rn, int standby, int assigned)
{
	struct memory_increment *incr, *new_incr;
	struct list_head *prev;
	u16 last_rn;

	new_incr = kzalloc(sizeof(*new_incr), GFP_KERNEL);
	if (!new_incr)
		return;
	new_incr->rn = rn;
	new_incr->standby = standby;
	last_rn = 0;
	prev = &sclp_mem_list;
	list_for_each_entry(incr, &sclp_mem_list, list) {
		if (assigned && incr->rn > rn)
			break;
		if (!assigned && incr->rn - last_rn > 1)
			break;
		last_rn = incr->rn;
		prev = &incr->list;
	}
	if (!assigned)
		new_incr->rn = last_rn + 1;
	if (new_incr->rn > rnmax) {
		kfree(new_incr);
		return;
	}
	list_add(&new_incr->list, prev);
}

struct read_storage_sccb {
	struct sccb_header header;
	u16 max_id;
	u16 assigned;
	u16 standby;
	u16 :16;
	u32 entries[0];
} __packed;

static int __init sclp_detect_standby_memory(void)
{
	struct read_storage_sccb *sccb;
	int i, id, assigned, rc;

	if (!early_read_info_sccb_valid)
		return 0;
	if ((sclp_facilities & 0xe00000000000ULL) != 0xe00000000000ULL)
		return 0;
	rc = -ENOMEM;
	sccb = (void *) __get_free_page(GFP_KERNEL | GFP_DMA);
	if (!sccb)
		goto out;
	assigned = 0;
	for (id = 0; id <= sclp_max_storage_id; id++) {
		memset(sccb, 0, PAGE_SIZE);
		sccb->header.length = PAGE_SIZE;
		rc = do_sync_request(0x00040001 | id << 8, sccb);
		if (rc)
			goto out;
		switch (sccb->header.response_code) {
		case 0x0010:
			set_bit(id, sclp_storage_ids);
			for (i = 0; i < sccb->assigned; i++) {
				if (!sccb->entries[i])
					continue;
				assigned++;
				insert_increment(sccb->entries[i] >> 16, 0, 1);
			}
			break;
		case 0x0310:
			break;
		case 0x0410:
			for (i = 0; i < sccb->assigned; i++) {
				if (!sccb->entries[i])
					continue;
				assigned++;
				insert_increment(sccb->entries[i] >> 16, 1, 1);
			}
			break;
		default:
			rc = -EIO;
			break;
		}
		if (!rc)
			sclp_max_storage_id = sccb->max_id;
	}
	if (rc || list_empty(&sclp_mem_list))
		goto out;
	for (i = 1; i <= rnmax - assigned; i++)
		insert_increment(0, 1, 0);
	rc = register_memory_notifier(&sclp_mem_nb);
	if (rc)
		goto out;
	sclp_add_standby_memory();
out:
	free_page((unsigned long) sccb);
	return rc;
}
__initcall(sclp_detect_standby_memory);

#endif /* CONFIG_MEMORY_HOTPLUG */

/*
 * Channel path configuration related functions.
 */