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[S390] Add support for memory hot-add via sclp.
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Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Heiko Carstens committed Jul 14, 2008
1 parent 421c175 commit e0bc249
Showing 1 changed file with 308 additions and 8 deletions.
316 changes: 308 additions & 8 deletions drivers/s390/char/sclp_cmd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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"
Expand Down Expand Up @@ -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)
{
Expand Down Expand Up @@ -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;
}

Expand Down Expand Up @@ -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.
*/
Expand Down

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