linux/drivers/misc/sgi-xp/xpc_partition.c

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/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2004-2008 Silicon Graphics, Inc. All Rights Reserved.
*/
/*
* Cross Partition Communication (XPC) partition support.
*
* This is the part of XPC that detects the presence/absence of
* other partitions. It provides a heartbeat and monitors the
* heartbeats of other partitions.
*
*/
#include <linux/device.h>
#include <linux/hardirq.h>
#include "xpc.h"
/* XPC is exiting flag */
int xpc_exiting;
/* this partition's reserved page pointers */
struct xpc_rsvd_page *xpc_rsvd_page;
static unsigned long *xpc_part_nasids;
unsigned long *xpc_mach_nasids;
static int xpc_nasid_mask_nbytes; /* #of bytes in nasid mask */
int xpc_nasid_mask_nlongs; /* #of longs in nasid mask */
struct xpc_partition *xpc_partitions;
/*
* Guarantee that the kmalloc'd memory is cacheline aligned.
*/
void *
xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
{
/* see if kmalloc will give us cachline aligned memory by default */
*base = kmalloc(size, flags);
if (*base == NULL)
return NULL;
if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
return *base;
kfree(*base);
/* nope, we'll have to do it ourselves */
*base = kmalloc(size + L1_CACHE_BYTES, flags);
if (*base == NULL)
return NULL;
return (void *)L1_CACHE_ALIGN((u64)*base);
}
/*
* Given a nasid, get the physical address of the partition's reserved page
* for that nasid. This function returns 0 on any error.
*/
static unsigned long
xpc_get_rsvd_page_pa(int nasid)
{
enum xp_retval ret;
u64 cookie = 0;
unsigned long rp_pa = nasid; /* seed with nasid */
size_t len = 0;
size_t buf_len = 0;
void *buf = buf;
void *buf_base = NULL;
enum xp_retval (*get_partition_rsvd_page_pa)
(void *, u64 *, unsigned long *, size_t *) =
xpc_arch_ops.get_partition_rsvd_page_pa;
while (1) {
/* !!! rp_pa will need to be _gpa on UV.
* ??? So do we save it into the architecture specific parts
* ??? of the xpc_partition structure? Do we rename this
* ??? function or have two versions? Rename rp_pa for UV to
* ??? rp_gpa?
*/
ret = get_partition_rsvd_page_pa(buf, &cookie, &rp_pa, &len);
dev_dbg(xpc_part, "SAL returned with ret=%d, cookie=0x%016lx, "
"address=0x%016lx, len=0x%016lx\n", ret,
(unsigned long)cookie, rp_pa, len);
if (ret != xpNeedMoreInfo)
break;
/* !!! L1_CACHE_ALIGN() is only a sn2-bte_copy requirement */
if (L1_CACHE_ALIGN(len) > buf_len) {
kfree(buf_base);
buf_len = L1_CACHE_ALIGN(len);
buf = xpc_kmalloc_cacheline_aligned(buf_len, GFP_KERNEL,
&buf_base);
if (buf_base == NULL) {
dev_err(xpc_part, "unable to kmalloc "
"len=0x%016lx\n", buf_len);
ret = xpNoMemory;
break;
}
}
ret = xp_remote_memcpy(xp_pa(buf), rp_pa, buf_len);
if (ret != xpSuccess) {
dev_dbg(xpc_part, "xp_remote_memcpy failed %d\n", ret);
break;
}
}
kfree(buf_base);
if (ret != xpSuccess)
rp_pa = 0;
dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
return rp_pa;
}
/*
* Fill the partition reserved page with the information needed by
* other partitions to discover we are alive and establish initial
* communications.
*/
int
xpc_setup_rsvd_page(void)
{
int ret;
struct xpc_rsvd_page *rp;
unsigned long rp_pa;
unsigned long new_ts_jiffies;
/* get the local reserved page's address */
preempt_disable();
rp_pa = xpc_get_rsvd_page_pa(xp_cpu_to_nasid(smp_processor_id()));
preempt_enable();
if (rp_pa == 0) {
dev_err(xpc_part, "SAL failed to locate the reserved page\n");
return -ESRCH;
}
rp = (struct xpc_rsvd_page *)__va(rp_pa);
if (rp->SAL_version < 3) {
/* SAL_versions < 3 had a SAL_partid defined as a u8 */
rp->SAL_partid &= 0xff;
}
BUG_ON(rp->SAL_partid != xp_partition_id);
if (rp->SAL_partid < 0 || rp->SAL_partid >= xp_max_npartitions) {
dev_err(xpc_part, "the reserved page's partid of %d is outside "
"supported range (< 0 || >= %d)\n", rp->SAL_partid,
xp_max_npartitions);
return -EINVAL;
}
rp->version = XPC_RP_VERSION;
rp->max_npartitions = xp_max_npartitions;
/* establish the actual sizes of the nasid masks */
if (rp->SAL_version == 1) {
/* SAL_version 1 didn't set the nasids_size field */
rp->SAL_nasids_size = 128;
}
xpc_nasid_mask_nbytes = rp->SAL_nasids_size;
xpc_nasid_mask_nlongs = BITS_TO_LONGS(rp->SAL_nasids_size *
BITS_PER_BYTE);
/* setup the pointers to the various items in the reserved page */
xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
ret = xpc_arch_ops.setup_rsvd_page(rp);
if (ret != 0)
return ret;
/*
* Set timestamp of when reserved page was setup by XPC.
* This signifies to the remote partition that our reserved
* page is initialized.
*/
new_ts_jiffies = jiffies;
if (new_ts_jiffies == 0 || new_ts_jiffies == rp->ts_jiffies)
new_ts_jiffies++;
rp->ts_jiffies = new_ts_jiffies;
xpc_rsvd_page = rp;
return 0;
}
void
xpc_teardown_rsvd_page(void)
{
/* a zero timestamp indicates our rsvd page is not initialized */
xpc_rsvd_page->ts_jiffies = 0;
}
/*
* Get a copy of a portion of the remote partition's rsvd page.
*
* remote_rp points to a buffer that is cacheline aligned for BTE copies and
* is large enough to contain a copy of their reserved page header and
* part_nasids mask.
*/
enum xp_retval
xpc_get_remote_rp(int nasid, unsigned long *discovered_nasids,
struct xpc_rsvd_page *remote_rp, unsigned long *remote_rp_pa)
{
int l;
enum xp_retval ret;
/* get the reserved page's physical address */
*remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
if (*remote_rp_pa == 0)
return xpNoRsvdPageAddr;
/* pull over the reserved page header and part_nasids mask */
ret = xp_remote_memcpy(xp_pa(remote_rp), *remote_rp_pa,
XPC_RP_HEADER_SIZE + xpc_nasid_mask_nbytes);
if (ret != xpSuccess)
return ret;
if (discovered_nasids != NULL) {
unsigned long *remote_part_nasids =
XPC_RP_PART_NASIDS(remote_rp);
for (l = 0; l < xpc_nasid_mask_nlongs; l++)
discovered_nasids[l] |= remote_part_nasids[l];
}
/* zero timestamp indicates the reserved page has not been setup */
if (remote_rp->ts_jiffies == 0)
return xpRsvdPageNotSet;
if (XPC_VERSION_MAJOR(remote_rp->version) !=
XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
return xpBadVersion;
}
/* check that both remote and local partids are valid for each side */
if (remote_rp->SAL_partid < 0 ||
remote_rp->SAL_partid >= xp_max_npartitions ||
remote_rp->max_npartitions <= xp_partition_id) {
return xpInvalidPartid;
}
if (remote_rp->SAL_partid == xp_partition_id)
return xpLocalPartid;
return xpSuccess;
}
/*
* See if the other side has responded to a partition deactivate request
* from us. Though we requested the remote partition to deactivate with regard
* to us, we really only need to wait for the other side to disengage from us.
*/
int
xpc_partition_disengaged(struct xpc_partition *part)
{
short partid = XPC_PARTID(part);
int disengaged;
disengaged = !xpc_arch_ops.partition_engaged(partid);
if (part->disengage_timeout) {
if (!disengaged) {
if (time_is_after_jiffies(part->disengage_timeout)) {
/* timelimit hasn't been reached yet */
return 0;
}
/*
* Other side hasn't responded to our deactivate
* request in a timely fashion, so assume it's dead.
*/
dev_info(xpc_part, "deactivate request to remote "
"partition %d timed out\n", partid);
xpc_disengage_timedout = 1;
xpc_arch_ops.assume_partition_disengaged(partid);
disengaged = 1;
}
part->disengage_timeout = 0;
/* cancel the timer function, provided it's not us */
if (!in_interrupt())
del_singleshot_timer_sync(&part->disengage_timer);
DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING &&
part->act_state != XPC_P_AS_INACTIVE);
if (part->act_state != XPC_P_AS_INACTIVE)
xpc_wakeup_channel_mgr(part);
xpc_arch_ops.cancel_partition_deactivation_request(part);
}
return disengaged;
}
/*
* Mark specified partition as active.
*/
enum xp_retval
xpc_mark_partition_active(struct xpc_partition *part)
{
unsigned long irq_flags;
enum xp_retval ret;
dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
spin_lock_irqsave(&part->act_lock, irq_flags);
if (part->act_state == XPC_P_AS_ACTIVATING) {
part->act_state = XPC_P_AS_ACTIVE;
ret = xpSuccess;
} else {
DBUG_ON(part->reason == xpSuccess);
ret = part->reason;
}
spin_unlock_irqrestore(&part->act_lock, irq_flags);
return ret;
}
/*
* Start the process of deactivating the specified partition.
*/
void
xpc_deactivate_partition(const int line, struct xpc_partition *part,
enum xp_retval reason)
{
unsigned long irq_flags;
spin_lock_irqsave(&part->act_lock, irq_flags);
if (part->act_state == XPC_P_AS_INACTIVE) {
XPC_SET_REASON(part, reason, line);
spin_unlock_irqrestore(&part->act_lock, irq_flags);
if (reason == xpReactivating) {
/* we interrupt ourselves to reactivate partition */
xpc_arch_ops.request_partition_reactivation(part);
}
return;
}
if (part->act_state == XPC_P_AS_DEACTIVATING) {
if ((part->reason == xpUnloading && reason != xpUnloading) ||
reason == xpReactivating) {
XPC_SET_REASON(part, reason, line);
}
spin_unlock_irqrestore(&part->act_lock, irq_flags);
return;
}
part->act_state = XPC_P_AS_DEACTIVATING;
XPC_SET_REASON(part, reason, line);
spin_unlock_irqrestore(&part->act_lock, irq_flags);
/* ask remote partition to deactivate with regard to us */
xpc_arch_ops.request_partition_deactivation(part);
/* set a timelimit on the disengage phase of the deactivation request */
part->disengage_timeout = jiffies + (xpc_disengage_timelimit * HZ);
part->disengage_timer.expires = part->disengage_timeout;
add_timer(&part->disengage_timer);
dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
XPC_PARTID(part), reason);
xpc_partition_going_down(part, reason);
}
/*
* Mark specified partition as inactive.
*/
void
xpc_mark_partition_inactive(struct xpc_partition *part)
{
unsigned long irq_flags;
dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
XPC_PARTID(part));
spin_lock_irqsave(&part->act_lock, irq_flags);
part->act_state = XPC_P_AS_INACTIVE;
spin_unlock_irqrestore(&part->act_lock, irq_flags);
part->remote_rp_pa = 0;
}
/*
* SAL has provided a partition and machine mask. The partition mask
* contains a bit for each even nasid in our partition. The machine
* mask contains a bit for each even nasid in the entire machine.
*
* Using those two bit arrays, we can determine which nasids are
* known in the machine. Each should also have a reserved page
* initialized if they are available for partitioning.
*/
void
xpc_discovery(void)
{
void *remote_rp_base;
struct xpc_rsvd_page *remote_rp;
unsigned long remote_rp_pa;
int region;
int region_size;
int max_regions;
int nasid;
struct xpc_rsvd_page *rp;
unsigned long *discovered_nasids;
enum xp_retval ret;
remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
xpc_nasid_mask_nbytes,
GFP_KERNEL, &remote_rp_base);
if (remote_rp == NULL)
return;
discovered_nasids = kzalloc(sizeof(long) * xpc_nasid_mask_nlongs,
GFP_KERNEL);
if (discovered_nasids == NULL) {
kfree(remote_rp_base);
return;
}
rp = (struct xpc_rsvd_page *)xpc_rsvd_page;
/*
* The term 'region' in this context refers to the minimum number of
* nodes that can comprise an access protection grouping. The access
* protection is in regards to memory, IOI and IPI.
*/
max_regions = 64;
region_size = xp_region_size;
switch (region_size) {
case 128:
max_regions *= 2;
case 64:
max_regions *= 2;
case 32:
max_regions *= 2;
region_size = 16;
DBUG_ON(!is_shub2());
}
for (region = 0; region < max_regions; region++) {
if (xpc_exiting)
break;
dev_dbg(xpc_part, "searching region %d\n", region);
for (nasid = (region * region_size * 2);
nasid < ((region + 1) * region_size * 2); nasid += 2) {
if (xpc_exiting)
break;
dev_dbg(xpc_part, "checking nasid %d\n", nasid);
if (test_bit(nasid / 2, xpc_part_nasids)) {
dev_dbg(xpc_part, "PROM indicates Nasid %d is "
"part of the local partition; skipping "
"region\n", nasid);
break;
}
if (!(test_bit(nasid / 2, xpc_mach_nasids))) {
dev_dbg(xpc_part, "PROM indicates Nasid %d was "
"not on Numa-Link network at reset\n",
nasid);
continue;
}
if (test_bit(nasid / 2, discovered_nasids)) {
dev_dbg(xpc_part, "Nasid %d is part of a "
"partition which was previously "
"discovered\n", nasid);
continue;
}
/* pull over the rsvd page header & part_nasids mask */
ret = xpc_get_remote_rp(nasid, discovered_nasids,
remote_rp, &remote_rp_pa);
if (ret != xpSuccess) {
dev_dbg(xpc_part, "unable to get reserved page "
"from nasid %d, reason=%d\n", nasid,
ret);
if (ret == xpLocalPartid)
break;
continue;
}
xpc_arch_ops.request_partition_activation(remote_rp,
remote_rp_pa, nasid);
}
}
kfree(discovered_nasids);
kfree(remote_rp_base);
}
/*
* Given a partid, get the nasids owned by that partition from the
* remote partition's reserved page.
*/
enum xp_retval
xpc_initiate_partid_to_nasids(short partid, void *nasid_mask)
{
struct xpc_partition *part;
unsigned long part_nasid_pa;
part = &xpc_partitions[partid];
if (part->remote_rp_pa == 0)
return xpPartitionDown;
memset(nasid_mask, 0, xpc_nasid_mask_nbytes);
part_nasid_pa = (unsigned long)XPC_RP_PART_NASIDS(part->remote_rp_pa);
return xp_remote_memcpy(xp_pa(nasid_mask), part_nasid_pa,
xpc_nasid_mask_nbytes);
}