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tegrakernel/kernel/kernel-4.9/drivers/misc/sgi-xp/xpc_sn2.c

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initial commit tegra kernel 32.6.1
2022-02-16 09:13:02 -06:00
/*
* 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) 2008-2009 Silicon Graphics, Inc. All Rights Reserved.
*/
/*
* Cross Partition Communication (XPC) sn2-based functions.
*
* Architecture specific implementation of common functions.
*
*/
#include <linux/delay.h>
#include <linux/slab.h>
#include <asm/uncached.h>
#include <asm/sn/mspec.h>
#include <asm/sn/sn_sal.h>
#include "xpc.h"
/*
* Define the number of u64s required to represent all the C-brick nasids
* as a bitmap. The cross-partition kernel modules deal only with
* C-brick nasids, thus the need for bitmaps which don't account for
* odd-numbered (non C-brick) nasids.
*/
#define XPC_MAX_PHYSNODES_SN2 (MAX_NUMALINK_NODES / 2)
#define XP_NASID_MASK_BYTES_SN2 ((XPC_MAX_PHYSNODES_SN2 + 7) / 8)
#define XP_NASID_MASK_WORDS_SN2 ((XPC_MAX_PHYSNODES_SN2 + 63) / 64)
/*
* Memory for XPC's amo variables is allocated by the MSPEC driver. These
* pages are located in the lowest granule. The lowest granule uses 4k pages
* for cached references and an alternate TLB handler to never provide a
* cacheable mapping for the entire region. This will prevent speculative
* reading of cached copies of our lines from being issued which will cause
* a PI FSB Protocol error to be generated by the SHUB. For XPC, we need 64
* amo variables (based on XP_MAX_NPARTITIONS_SN2) to identify the senders of
* NOTIFY IRQs, 128 amo variables (based on XP_NASID_MASK_WORDS_SN2) to identify
* the senders of ACTIVATE IRQs, 1 amo variable to identify which remote
* partitions (i.e., XPCs) consider themselves currently engaged with the
* local XPC and 1 amo variable to request partition deactivation.
*/
#define XPC_NOTIFY_IRQ_AMOS_SN2 0
#define XPC_ACTIVATE_IRQ_AMOS_SN2 (XPC_NOTIFY_IRQ_AMOS_SN2 + \
XP_MAX_NPARTITIONS_SN2)
#define XPC_ENGAGED_PARTITIONS_AMO_SN2 (XPC_ACTIVATE_IRQ_AMOS_SN2 + \
XP_NASID_MASK_WORDS_SN2)
#define XPC_DEACTIVATE_REQUEST_AMO_SN2 (XPC_ENGAGED_PARTITIONS_AMO_SN2 + 1)
/*
* Buffer used to store a local copy of portions of a remote partition's
* reserved page (either its header and part_nasids mask, or its vars).
*/
static void *xpc_remote_copy_buffer_base_sn2;
static char *xpc_remote_copy_buffer_sn2;
static struct xpc_vars_sn2 *xpc_vars_sn2;
static struct xpc_vars_part_sn2 *xpc_vars_part_sn2;
static int
xpc_setup_partitions_sn2(void)
{
/* nothing needs to be done */
return 0;
}
static void
xpc_teardown_partitions_sn2(void)
{
/* nothing needs to be done */
}
/* SH_IPI_ACCESS shub register value on startup */
static u64 xpc_sh1_IPI_access_sn2;
static u64 xpc_sh2_IPI_access0_sn2;
static u64 xpc_sh2_IPI_access1_sn2;
static u64 xpc_sh2_IPI_access2_sn2;
static u64 xpc_sh2_IPI_access3_sn2;
/*
* Change protections to allow IPI operations.
*/
static void
xpc_allow_IPI_ops_sn2(void)
{
int node;
int nasid;
/* !!! The following should get moved into SAL. */
if (is_shub2()) {
xpc_sh2_IPI_access0_sn2 =
(u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
xpc_sh2_IPI_access1_sn2 =
(u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
xpc_sh2_IPI_access2_sn2 =
(u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
xpc_sh2_IPI_access3_sn2 =
(u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
for_each_online_node(node) {
nasid = cnodeid_to_nasid(node);
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
-1UL);
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
-1UL);
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
-1UL);
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
-1UL);
}
} else {
xpc_sh1_IPI_access_sn2 =
(u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
for_each_online_node(node) {
nasid = cnodeid_to_nasid(node);
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
-1UL);
}
}
}
/*
* Restrict protections to disallow IPI operations.
*/
static void
xpc_disallow_IPI_ops_sn2(void)
{
int node;
int nasid;
/* !!! The following should get moved into SAL. */
if (is_shub2()) {
for_each_online_node(node) {
nasid = cnodeid_to_nasid(node);
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
xpc_sh2_IPI_access0_sn2);
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
xpc_sh2_IPI_access1_sn2);
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
xpc_sh2_IPI_access2_sn2);
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
xpc_sh2_IPI_access3_sn2);
}
} else {
for_each_online_node(node) {
nasid = cnodeid_to_nasid(node);
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
xpc_sh1_IPI_access_sn2);
}
}
}
/*
* The following set of functions are used for the sending and receiving of
* IRQs (also known as IPIs). There are two flavors of IRQs, one that is
* associated with partition activity (SGI_XPC_ACTIVATE) and the other that
* is associated with channel activity (SGI_XPC_NOTIFY).
*/
static u64
xpc_receive_IRQ_amo_sn2(struct amo *amo)
{
return FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_CLEAR);
}
static enum xp_retval
xpc_send_IRQ_sn2(struct amo *amo, u64 flag, int nasid, int phys_cpuid,
int vector)
{
int ret = 0;
unsigned long irq_flags;
local_irq_save(irq_flags);
FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR, flag);
sn_send_IPI_phys(nasid, phys_cpuid, vector, 0);
/*
* We must always use the nofault function regardless of whether we
* are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
* didn't, we'd never know that the other partition is down and would
* keep sending IRQs and amos to it until the heartbeat times out.
*/
ret = xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->variable),
xp_nofault_PIOR_target));
local_irq_restore(irq_flags);
return (ret == 0) ? xpSuccess : xpPioReadError;
}
static struct amo *
xpc_init_IRQ_amo_sn2(int index)
{
struct amo *amo = xpc_vars_sn2->amos_page + index;
(void)xpc_receive_IRQ_amo_sn2(amo); /* clear amo variable */
return amo;
}
/*
* Functions associated with SGI_XPC_ACTIVATE IRQ.
*/
/*
* Notify the heartbeat check thread that an activate IRQ has been received.
*/
static irqreturn_t
xpc_handle_activate_IRQ_sn2(int irq, void *dev_id)
{
unsigned long irq_flags;
spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
xpc_activate_IRQ_rcvd++;
spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
wake_up_interruptible(&xpc_activate_IRQ_wq);
return IRQ_HANDLED;
}
/*
* Flag the appropriate amo variable and send an IRQ to the specified node.
*/
static void
xpc_send_activate_IRQ_sn2(unsigned long amos_page_pa, int from_nasid,
int to_nasid, int to_phys_cpuid)
{
struct amo *amos = (struct amo *)__va(amos_page_pa +
(XPC_ACTIVATE_IRQ_AMOS_SN2 *
sizeof(struct amo)));
(void)xpc_send_IRQ_sn2(&amos[BIT_WORD(from_nasid / 2)],
BIT_MASK(from_nasid / 2), to_nasid,
to_phys_cpuid, SGI_XPC_ACTIVATE);
}
static void
xpc_send_local_activate_IRQ_sn2(int from_nasid)
{
unsigned long irq_flags;
struct amo *amos = (struct amo *)__va(xpc_vars_sn2->amos_page_pa +
(XPC_ACTIVATE_IRQ_AMOS_SN2 *
sizeof(struct amo)));
/* fake the sending and receipt of an activate IRQ from remote nasid */
FETCHOP_STORE_OP(TO_AMO((u64)&amos[BIT_WORD(from_nasid / 2)].variable),
FETCHOP_OR, BIT_MASK(from_nasid / 2));
spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
xpc_activate_IRQ_rcvd++;
spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
wake_up_interruptible(&xpc_activate_IRQ_wq);
}
/*
* Functions associated with SGI_XPC_NOTIFY IRQ.
*/
/*
* Check to see if any chctl flags were sent from the specified partition.
*/
static void
xpc_check_for_sent_chctl_flags_sn2(struct xpc_partition *part)
{
union xpc_channel_ctl_flags chctl;
unsigned long irq_flags;
chctl.all_flags = xpc_receive_IRQ_amo_sn2(part->sn.sn2.
local_chctl_amo_va);
if (chctl.all_flags == 0)
return;
spin_lock_irqsave(&part->chctl_lock, irq_flags);
part->chctl.all_flags |= chctl.all_flags;
spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
dev_dbg(xpc_chan, "received notify IRQ from partid=%d, chctl.all_flags="
"0x%llx\n", XPC_PARTID(part), chctl.all_flags);
xpc_wakeup_channel_mgr(part);
}
/*
* Handle the receipt of a SGI_XPC_NOTIFY IRQ by seeing whether the specified
* partition actually sent it. Since SGI_XPC_NOTIFY IRQs may be shared by more
* than one partition, we use an amo structure per partition to indicate
* whether a partition has sent an IRQ or not. If it has, then wake up the
* associated kthread to handle it.
*
* All SGI_XPC_NOTIFY IRQs received by XPC are the result of IRQs sent by XPC
* running on other partitions.
*
* Noteworthy Arguments:
*
* irq - Interrupt ReQuest number. NOT USED.
*
* dev_id - partid of IRQ's potential sender.
*/
static irqreturn_t
xpc_handle_notify_IRQ_sn2(int irq, void *dev_id)
{
short partid = (short)(u64)dev_id;
struct xpc_partition *part = &xpc_partitions[partid];
DBUG_ON(partid < 0 || partid >= XP_MAX_NPARTITIONS_SN2);
if (xpc_part_ref(part)) {
xpc_check_for_sent_chctl_flags_sn2(part);
xpc_part_deref(part);
}
return IRQ_HANDLED;
}
/*
* Check to see if xpc_handle_notify_IRQ_sn2() dropped any IRQs on the floor
* because the write to their associated amo variable completed after the IRQ
* was received.
*/
static void
xpc_check_for_dropped_notify_IRQ_sn2(struct xpc_partition *part)
{
struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
if (xpc_part_ref(part)) {
xpc_check_for_sent_chctl_flags_sn2(part);
part_sn2->dropped_notify_IRQ_timer.expires = jiffies +
XPC_DROPPED_NOTIFY_IRQ_WAIT_INTERVAL;
add_timer(&part_sn2->dropped_notify_IRQ_timer);
xpc_part_deref(part);
}
}
/*
* Send a notify IRQ to the remote partition that is associated with the
* specified channel.
*/
static void
xpc_send_notify_IRQ_sn2(struct xpc_channel *ch, u8 chctl_flag,
char *chctl_flag_string, unsigned long *irq_flags)
{
struct xpc_partition *part = &xpc_partitions[ch->partid];
struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
union xpc_channel_ctl_flags chctl = { 0 };
enum xp_retval ret;
if (likely(part->act_state != XPC_P_AS_DEACTIVATING)) {
chctl.flags[ch->number] = chctl_flag;
ret = xpc_send_IRQ_sn2(part_sn2->remote_chctl_amo_va,
chctl.all_flags,
part_sn2->notify_IRQ_nasid,
part_sn2->notify_IRQ_phys_cpuid,
SGI_XPC_NOTIFY);
dev_dbg(xpc_chan, "%s sent to partid=%d, channel=%d, ret=%d\n",
chctl_flag_string, ch->partid, ch->number, ret);
if (unlikely(ret != xpSuccess)) {
if (irq_flags != NULL)
spin_unlock_irqrestore(&ch->lock, *irq_flags);
XPC_DEACTIVATE_PARTITION(part, ret);
if (irq_flags != NULL)
spin_lock_irqsave(&ch->lock, *irq_flags);
}
}
}
#define XPC_SEND_NOTIFY_IRQ_SN2(_ch, _ipi_f, _irq_f) \
xpc_send_notify_IRQ_sn2(_ch, _ipi_f, #_ipi_f, _irq_f)
/*
* Make it look like the remote partition, which is associated with the
* specified channel, sent us a notify IRQ. This faked IRQ will be handled
* by xpc_check_for_dropped_notify_IRQ_sn2().
*/
static void
xpc_send_local_notify_IRQ_sn2(struct xpc_channel *ch, u8 chctl_flag,
char *chctl_flag_string)
{
struct xpc_partition *part = &xpc_partitions[ch->partid];
union xpc_channel_ctl_flags chctl = { 0 };
chctl.flags[ch->number] = chctl_flag;
FETCHOP_STORE_OP(TO_AMO((u64)&part->sn.sn2.local_chctl_amo_va->
variable), FETCHOP_OR, chctl.all_flags);
dev_dbg(xpc_chan, "%s sent local from partid=%d, channel=%d\n",
chctl_flag_string, ch->partid, ch->number);
}
#define XPC_SEND_LOCAL_NOTIFY_IRQ_SN2(_ch, _ipi_f) \
xpc_send_local_notify_IRQ_sn2(_ch, _ipi_f, #_ipi_f)
static void
xpc_send_chctl_closerequest_sn2(struct xpc_channel *ch,
unsigned long *irq_flags)
{
struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
args->reason = ch->reason;
XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_CLOSEREQUEST, irq_flags);
}
static void
xpc_send_chctl_closereply_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
{
XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_CLOSEREPLY, irq_flags);
}
static void
xpc_send_chctl_openrequest_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
{
struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
args->entry_size = ch->entry_size;
args->local_nentries = ch->local_nentries;
XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_OPENREQUEST, irq_flags);
}
static void
xpc_send_chctl_openreply_sn2(struct xpc_channel *ch, unsigned long *irq_flags)
{
struct xpc_openclose_args *args = ch->sn.sn2.local_openclose_args;
args->remote_nentries = ch->remote_nentries;
args->local_nentries = ch->local_nentries;
args->local_msgqueue_pa = xp_pa(ch->sn.sn2.local_msgqueue);
XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_OPENREPLY, irq_flags);
}
static void
xpc_send_chctl_opencomplete_sn2(struct xpc_channel *ch,
unsigned long *irq_flags)
{
XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_OPENCOMPLETE, irq_flags);
}
static void
xpc_send_chctl_msgrequest_sn2(struct xpc_channel *ch)
{
XPC_SEND_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_MSGREQUEST, NULL);
}
static void
xpc_send_chctl_local_msgrequest_sn2(struct xpc_channel *ch)
{
XPC_SEND_LOCAL_NOTIFY_IRQ_SN2(ch, XPC_CHCTL_MSGREQUEST);
}
static enum xp_retval
xpc_save_remote_msgqueue_pa_sn2(struct xpc_channel *ch,
unsigned long msgqueue_pa)
{
ch->sn.sn2.remote_msgqueue_pa = msgqueue_pa;
return xpSuccess;
}
/*
* This next set of functions are used to keep track of when a partition is
* potentially engaged in accessing memory belonging to another partition.
*/
static void
xpc_indicate_partition_engaged_sn2(struct xpc_partition *part)
{
unsigned long irq_flags;
struct amo *amo = (struct amo *)__va(part->sn.sn2.remote_amos_page_pa +
(XPC_ENGAGED_PARTITIONS_AMO_SN2 *
sizeof(struct amo)));
local_irq_save(irq_flags);
/* set bit corresponding to our partid in remote partition's amo */
FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR,
BIT(sn_partition_id));
/*
* We must always use the nofault function regardless of whether we
* are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
* didn't, we'd never know that the other partition is down and would
* keep sending IRQs and amos to it until the heartbeat times out.
*/
(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
variable),
xp_nofault_PIOR_target));
local_irq_restore(irq_flags);
}
static void
xpc_indicate_partition_disengaged_sn2(struct xpc_partition *part)
{
struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
unsigned long irq_flags;
struct amo *amo = (struct amo *)__va(part_sn2->remote_amos_page_pa +
(XPC_ENGAGED_PARTITIONS_AMO_SN2 *
sizeof(struct amo)));
local_irq_save(irq_flags);
/* clear bit corresponding to our partid in remote partition's amo */
FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
~BIT(sn_partition_id));
/*
* We must always use the nofault function regardless of whether we
* are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
* didn't, we'd never know that the other partition is down and would
* keep sending IRQs and amos to it until the heartbeat times out.
*/
(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
variable),
xp_nofault_PIOR_target));
local_irq_restore(irq_flags);
/*
* Send activate IRQ to get other side to see that we've cleared our
* bit in their engaged partitions amo.
*/
xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
cnodeid_to_nasid(0),
part_sn2->activate_IRQ_nasid,
part_sn2->activate_IRQ_phys_cpuid);
}
static void
xpc_assume_partition_disengaged_sn2(short partid)
{
struct amo *amo = xpc_vars_sn2->amos_page +
XPC_ENGAGED_PARTITIONS_AMO_SN2;
/* clear bit(s) based on partid mask in our partition's amo */
FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
~BIT(partid));
}
static int
xpc_partition_engaged_sn2(short partid)
{
struct amo *amo = xpc_vars_sn2->amos_page +
XPC_ENGAGED_PARTITIONS_AMO_SN2;
/* our partition's amo variable ANDed with partid mask */
return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
BIT(partid)) != 0;
}
static int
xpc_any_partition_engaged_sn2(void)
{
struct amo *amo = xpc_vars_sn2->amos_page +
XPC_ENGAGED_PARTITIONS_AMO_SN2;
/* our partition's amo variable */
return FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) != 0;
}
/* original protection values for each node */
static u64 xpc_prot_vec_sn2[MAX_NUMNODES];
/*
* Change protections to allow amo operations on non-Shub 1.1 systems.
*/
static enum xp_retval
xpc_allow_amo_ops_sn2(struct amo *amos_page)
{
enum xp_retval ret = xpSuccess;
/*
* On SHUB 1.1, we cannot call sn_change_memprotect() since the BIST
* collides with memory operations. On those systems we call
* xpc_allow_amo_ops_shub_wars_1_1_sn2() instead.
*/
if (!enable_shub_wars_1_1())
ret = xp_expand_memprotect(ia64_tpa((u64)amos_page), PAGE_SIZE);
return ret;
}
/*
* Change protections to allow amo operations on Shub 1.1 systems.
*/
static void
xpc_allow_amo_ops_shub_wars_1_1_sn2(void)
{
int node;
int nasid;
if (!enable_shub_wars_1_1())
return;
for_each_online_node(node) {
nasid = cnodeid_to_nasid(node);
/* save current protection values */
xpc_prot_vec_sn2[node] =
(u64)HUB_L((u64 *)GLOBAL_MMR_ADDR(nasid,
SH1_MD_DQLP_MMR_DIR_PRIVEC0));
/* open up everything */
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
SH1_MD_DQLP_MMR_DIR_PRIVEC0),
-1UL);
HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
SH1_MD_DQRP_MMR_DIR_PRIVEC0),
-1UL);
}
}
static enum xp_retval
xpc_get_partition_rsvd_page_pa_sn2(void *buf, u64 *cookie, unsigned long *rp_pa,
size_t *len)
{
s64 status;
enum xp_retval ret;
status = sn_partition_reserved_page_pa((u64)buf, cookie,
(u64 *)rp_pa, (u64 *)len);
if (status == SALRET_OK)
ret = xpSuccess;
else if (status == SALRET_MORE_PASSES)
ret = xpNeedMoreInfo;
else
ret = xpSalError;
return ret;
}
static int
xpc_setup_rsvd_page_sn2(struct xpc_rsvd_page *rp)
{
struct amo *amos_page;
int i;
int ret;
xpc_vars_sn2 = XPC_RP_VARS(rp);
rp->sn.sn2.vars_pa = xp_pa(xpc_vars_sn2);
/* vars_part array follows immediately after vars */
xpc_vars_part_sn2 = (struct xpc_vars_part_sn2 *)((u8 *)XPC_RP_VARS(rp) +
XPC_RP_VARS_SIZE);
/*
* Before clearing xpc_vars_sn2, see if a page of amos had been
* previously allocated. If not we'll need to allocate one and set
* permissions so that cross-partition amos are allowed.
*
* The allocated amo page needs MCA reporting to remain disabled after
* XPC has unloaded. To make this work, we keep a copy of the pointer
* to this page (i.e., amos_page) in the struct xpc_vars_sn2 structure,
* which is pointed to by the reserved page, and re-use that saved copy
* on subsequent loads of XPC. This amo page is never freed, and its
* memory protections are never restricted.
*/
amos_page = xpc_vars_sn2->amos_page;
if (amos_page == NULL) {
amos_page = (struct amo *)TO_AMO(uncached_alloc_page(0, 1));
if (amos_page == NULL) {
dev_err(xpc_part, "can't allocate page of amos\n");
return -ENOMEM;
}
/*
* Open up amo-R/W to cpu. This is done on Shub 1.1 systems
* when xpc_allow_amo_ops_shub_wars_1_1_sn2() is called.
*/
ret = xpc_allow_amo_ops_sn2(amos_page);
if (ret != xpSuccess) {
dev_err(xpc_part, "can't allow amo operations\n");
uncached_free_page(__IA64_UNCACHED_OFFSET |
TO_PHYS((u64)amos_page), 1);
return -EPERM;
}
}
/* clear xpc_vars_sn2 */
memset(xpc_vars_sn2, 0, sizeof(struct xpc_vars_sn2));
xpc_vars_sn2->version = XPC_V_VERSION;
xpc_vars_sn2->activate_IRQ_nasid = cpuid_to_nasid(0);
xpc_vars_sn2->activate_IRQ_phys_cpuid = cpu_physical_id(0);
xpc_vars_sn2->vars_part_pa = xp_pa(xpc_vars_part_sn2);
xpc_vars_sn2->amos_page_pa = ia64_tpa((u64)amos_page);
xpc_vars_sn2->amos_page = amos_page; /* save for next load of XPC */
/* clear xpc_vars_part_sn2 */
memset((u64 *)xpc_vars_part_sn2, 0, sizeof(struct xpc_vars_part_sn2) *
XP_MAX_NPARTITIONS_SN2);
/* initialize the activate IRQ related amo variables */
for (i = 0; i < xpc_nasid_mask_nlongs; i++)
(void)xpc_init_IRQ_amo_sn2(XPC_ACTIVATE_IRQ_AMOS_SN2 + i);
/* initialize the engaged remote partitions related amo variables */
(void)xpc_init_IRQ_amo_sn2(XPC_ENGAGED_PARTITIONS_AMO_SN2);
(void)xpc_init_IRQ_amo_sn2(XPC_DEACTIVATE_REQUEST_AMO_SN2);
return 0;
}
static int
xpc_hb_allowed_sn2(short partid, void *heartbeating_to_mask)
{
return test_bit(partid, heartbeating_to_mask);
}
static void
xpc_allow_hb_sn2(short partid)
{
DBUG_ON(xpc_vars_sn2 == NULL);
set_bit(partid, xpc_vars_sn2->heartbeating_to_mask);
}
static void
xpc_disallow_hb_sn2(short partid)
{
DBUG_ON(xpc_vars_sn2 == NULL);
clear_bit(partid, xpc_vars_sn2->heartbeating_to_mask);
}
static void
xpc_disallow_all_hbs_sn2(void)
{
DBUG_ON(xpc_vars_sn2 == NULL);
bitmap_zero(xpc_vars_sn2->heartbeating_to_mask, xp_max_npartitions);
}
static void
xpc_increment_heartbeat_sn2(void)
{
xpc_vars_sn2->heartbeat++;
}
static void
xpc_offline_heartbeat_sn2(void)
{
xpc_increment_heartbeat_sn2();
xpc_vars_sn2->heartbeat_offline = 1;
}
static void
xpc_online_heartbeat_sn2(void)
{
xpc_increment_heartbeat_sn2();
xpc_vars_sn2->heartbeat_offline = 0;
}
static void
xpc_heartbeat_init_sn2(void)
{
DBUG_ON(xpc_vars_sn2 == NULL);
bitmap_zero(xpc_vars_sn2->heartbeating_to_mask, XP_MAX_NPARTITIONS_SN2);
xpc_online_heartbeat_sn2();
}
static void
xpc_heartbeat_exit_sn2(void)
{
xpc_offline_heartbeat_sn2();
}
static enum xp_retval
xpc_get_remote_heartbeat_sn2(struct xpc_partition *part)
{
struct xpc_vars_sn2 *remote_vars;
enum xp_retval ret;
remote_vars = (struct xpc_vars_sn2 *)xpc_remote_copy_buffer_sn2;
/* pull the remote vars structure that contains the heartbeat */
ret = xp_remote_memcpy(xp_pa(remote_vars),
part->sn.sn2.remote_vars_pa,
XPC_RP_VARS_SIZE);
if (ret != xpSuccess)
return ret;
dev_dbg(xpc_part, "partid=%d, heartbeat=%lld, last_heartbeat=%lld, "
"heartbeat_offline=%lld, HB_mask[0]=0x%lx\n", XPC_PARTID(part),
remote_vars->heartbeat, part->last_heartbeat,
remote_vars->heartbeat_offline,
remote_vars->heartbeating_to_mask[0]);
if ((remote_vars->heartbeat == part->last_heartbeat &&
!remote_vars->heartbeat_offline) ||
!xpc_hb_allowed_sn2(sn_partition_id,
remote_vars->heartbeating_to_mask)) {
ret = xpNoHeartbeat;
} else {
part->last_heartbeat = remote_vars->heartbeat;
}
return ret;
}
/*
* Get a copy of the remote partition's XPC variables from the reserved page.
*
* remote_vars points to a buffer that is cacheline aligned for BTE copies and
* assumed to be of size XPC_RP_VARS_SIZE.
*/
static enum xp_retval
xpc_get_remote_vars_sn2(unsigned long remote_vars_pa,
struct xpc_vars_sn2 *remote_vars)
{
enum xp_retval ret;
if (remote_vars_pa == 0)
return xpVarsNotSet;
/* pull over the cross partition variables */
ret = xp_remote_memcpy(xp_pa(remote_vars), remote_vars_pa,
XPC_RP_VARS_SIZE);
if (ret != xpSuccess)
return ret;
if (XPC_VERSION_MAJOR(remote_vars->version) !=
XPC_VERSION_MAJOR(XPC_V_VERSION)) {
return xpBadVersion;
}
return xpSuccess;
}
static void
xpc_request_partition_activation_sn2(struct xpc_rsvd_page *remote_rp,
unsigned long remote_rp_pa, int nasid)
{
xpc_send_local_activate_IRQ_sn2(nasid);
}
static void
xpc_request_partition_reactivation_sn2(struct xpc_partition *part)
{
xpc_send_local_activate_IRQ_sn2(part->sn.sn2.activate_IRQ_nasid);
}
static void
xpc_request_partition_deactivation_sn2(struct xpc_partition *part)
{
struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
unsigned long irq_flags;
struct amo *amo = (struct amo *)__va(part_sn2->remote_amos_page_pa +
(XPC_DEACTIVATE_REQUEST_AMO_SN2 *
sizeof(struct amo)));
local_irq_save(irq_flags);
/* set bit corresponding to our partid in remote partition's amo */
FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_OR,
BIT(sn_partition_id));
/*
* We must always use the nofault function regardless of whether we
* are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
* didn't, we'd never know that the other partition is down and would
* keep sending IRQs and amos to it until the heartbeat times out.
*/
(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
variable),
xp_nofault_PIOR_target));
local_irq_restore(irq_flags);
/*
* Send activate IRQ to get other side to see that we've set our
* bit in their deactivate request amo.
*/
xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
cnodeid_to_nasid(0),
part_sn2->activate_IRQ_nasid,
part_sn2->activate_IRQ_phys_cpuid);
}
static void
xpc_cancel_partition_deactivation_request_sn2(struct xpc_partition *part)
{
unsigned long irq_flags;
struct amo *amo = (struct amo *)__va(part->sn.sn2.remote_amos_page_pa +
(XPC_DEACTIVATE_REQUEST_AMO_SN2 *
sizeof(struct amo)));
local_irq_save(irq_flags);
/* clear bit corresponding to our partid in remote partition's amo */
FETCHOP_STORE_OP(TO_AMO((u64)&amo->variable), FETCHOP_AND,
~BIT(sn_partition_id));
/*
* We must always use the nofault function regardless of whether we
* are on a Shub 1.1 system or a Shub 1.2 slice 0xc processor. If we
* didn't, we'd never know that the other partition is down and would
* keep sending IRQs and amos to it until the heartbeat times out.
*/
(void)xp_nofault_PIOR((u64 *)GLOBAL_MMR_ADDR(NASID_GET(&amo->
variable),
xp_nofault_PIOR_target));
local_irq_restore(irq_flags);
}
static int
xpc_partition_deactivation_requested_sn2(short partid)
{
struct amo *amo = xpc_vars_sn2->amos_page +
XPC_DEACTIVATE_REQUEST_AMO_SN2;
/* our partition's amo variable ANDed with partid mask */
return (FETCHOP_LOAD_OP(TO_AMO((u64)&amo->variable), FETCHOP_LOAD) &
BIT(partid)) != 0;
}
/*
* Update the remote partition's info.
*/
static void
xpc_update_partition_info_sn2(struct xpc_partition *part, u8 remote_rp_version,
unsigned long *remote_rp_ts_jiffies,
unsigned long remote_rp_pa,
unsigned long remote_vars_pa,
struct xpc_vars_sn2 *remote_vars)
{
struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
part->remote_rp_version = remote_rp_version;
dev_dbg(xpc_part, " remote_rp_version = 0x%016x\n",
part->remote_rp_version);
part->remote_rp_ts_jiffies = *remote_rp_ts_jiffies;
dev_dbg(xpc_part, " remote_rp_ts_jiffies = 0x%016lx\n",
part->remote_rp_ts_jiffies);
part->remote_rp_pa = remote_rp_pa;
dev_dbg(xpc_part, " remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
part_sn2->remote_vars_pa = remote_vars_pa;
dev_dbg(xpc_part, " remote_vars_pa = 0x%016lx\n",
part_sn2->remote_vars_pa);
part->last_heartbeat = remote_vars->heartbeat - 1;
dev_dbg(xpc_part, " last_heartbeat = 0x%016llx\n",
part->last_heartbeat);
part_sn2->remote_vars_part_pa = remote_vars->vars_part_pa;
dev_dbg(xpc_part, " remote_vars_part_pa = 0x%016lx\n",
part_sn2->remote_vars_part_pa);
part_sn2->activate_IRQ_nasid = remote_vars->activate_IRQ_nasid;
dev_dbg(xpc_part, " activate_IRQ_nasid = 0x%x\n",
part_sn2->activate_IRQ_nasid);
part_sn2->activate_IRQ_phys_cpuid =
remote_vars->activate_IRQ_phys_cpuid;
dev_dbg(xpc_part, " activate_IRQ_phys_cpuid = 0x%x\n",
part_sn2->activate_IRQ_phys_cpuid);
part_sn2->remote_amos_page_pa = remote_vars->amos_page_pa;
dev_dbg(xpc_part, " remote_amos_page_pa = 0x%lx\n",
part_sn2->remote_amos_page_pa);
part_sn2->remote_vars_version = remote_vars->version;
dev_dbg(xpc_part, " remote_vars_version = 0x%x\n",
part_sn2->remote_vars_version);
}
/*
* Prior code has determined the nasid which generated a activate IRQ.
* Inspect that nasid to determine if its partition needs to be activated
* or deactivated.
*
* A partition is considered "awaiting activation" if our partition
* flags indicate it is not active and it has a heartbeat. A
* partition is considered "awaiting deactivation" if our partition
* flags indicate it is active but it has no heartbeat or it is not
* sending its heartbeat to us.
*
* To determine the heartbeat, the remote nasid must have a properly
* initialized reserved page.
*/
static void
xpc_identify_activate_IRQ_req_sn2(int nasid)
{
struct xpc_rsvd_page *remote_rp;
struct xpc_vars_sn2 *remote_vars;
unsigned long remote_rp_pa;
unsigned long remote_vars_pa;
int remote_rp_version;
int reactivate = 0;
unsigned long remote_rp_ts_jiffies = 0;
short partid;
struct xpc_partition *part;
struct xpc_partition_sn2 *part_sn2;
enum xp_retval ret;
/* pull over the reserved page structure */
remote_rp = (struct xpc_rsvd_page *)xpc_remote_copy_buffer_sn2;
ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
if (ret != xpSuccess) {
dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
"which sent interrupt, reason=%d\n", nasid, ret);
return;
}
remote_vars_pa = remote_rp->sn.sn2.vars_pa;
remote_rp_version = remote_rp->version;
remote_rp_ts_jiffies = remote_rp->ts_jiffies;
partid = remote_rp->SAL_partid;
part = &xpc_partitions[partid];
part_sn2 = &part->sn.sn2;
/* pull over the cross partition variables */
remote_vars = (struct xpc_vars_sn2 *)xpc_remote_copy_buffer_sn2;
ret = xpc_get_remote_vars_sn2(remote_vars_pa, remote_vars);
if (ret != xpSuccess) {
dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
"which sent interrupt, reason=%d\n", nasid, ret);
XPC_DEACTIVATE_PARTITION(part, ret);
return;
}
part->activate_IRQ_rcvd++;
dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
"%lld:0x%lx\n", (int)nasid, (int)partid,
part->activate_IRQ_rcvd,
remote_vars->heartbeat, remote_vars->heartbeating_to_mask[0]);
if (xpc_partition_disengaged(part) &&
part->act_state == XPC_P_AS_INACTIVE) {
xpc_update_partition_info_sn2(part, remote_rp_version,
&remote_rp_ts_jiffies,
remote_rp_pa, remote_vars_pa,
remote_vars);
if (xpc_partition_deactivation_requested_sn2(partid)) {
/*
* Other side is waiting on us to deactivate even though
* we already have.
*/
return;
}
xpc_activate_partition(part);
return;
}
DBUG_ON(part->remote_rp_version == 0);
DBUG_ON(part_sn2->remote_vars_version == 0);
if (remote_rp_ts_jiffies != part->remote_rp_ts_jiffies) {
/* the other side rebooted */
DBUG_ON(xpc_partition_engaged_sn2(partid));
DBUG_ON(xpc_partition_deactivation_requested_sn2(partid));
xpc_update_partition_info_sn2(part, remote_rp_version,
&remote_rp_ts_jiffies,
remote_rp_pa, remote_vars_pa,
remote_vars);
reactivate = 1;
}
if (part->disengage_timeout > 0 && !xpc_partition_disengaged(part)) {
/* still waiting on other side to disengage from us */
return;
}
if (reactivate)
XPC_DEACTIVATE_PARTITION(part, xpReactivating);
else if (xpc_partition_deactivation_requested_sn2(partid))
XPC_DEACTIVATE_PARTITION(part, xpOtherGoingDown);
}
/*
* Loop through the activation amo variables and process any bits
* which are set. Each bit indicates a nasid sending a partition
* activation or deactivation request.
*
* Return #of IRQs detected.
*/
int
xpc_identify_activate_IRQ_sender_sn2(void)
{
int l;
int b;
unsigned long nasid_mask_long;
u64 nasid; /* remote nasid */
int n_IRQs_detected = 0;
struct amo *act_amos;
act_amos = xpc_vars_sn2->amos_page + XPC_ACTIVATE_IRQ_AMOS_SN2;
/* scan through activate amo variables looking for non-zero entries */
for (l = 0; l < xpc_nasid_mask_nlongs; l++) {
if (xpc_exiting)
break;
nasid_mask_long = xpc_receive_IRQ_amo_sn2(&act_amos[l]);
b = find_first_bit(&nasid_mask_long, BITS_PER_LONG);
if (b >= BITS_PER_LONG) {
/* no IRQs from nasids in this amo variable */
continue;
}
dev_dbg(xpc_part, "amo[%d] gave back 0x%lx\n", l,
nasid_mask_long);
/*
* If this nasid has been added to the machine since
* our partition was reset, this will retain the
* remote nasid in our reserved pages machine mask.
* This is used in the event of module reload.
*/
xpc_mach_nasids[l] |= nasid_mask_long;
/* locate the nasid(s) which sent interrupts */
do {
n_IRQs_detected++;
nasid = (l * BITS_PER_LONG + b) * 2;
dev_dbg(xpc_part, "interrupt from nasid %lld\n", nasid);
xpc_identify_activate_IRQ_req_sn2(nasid);
b = find_next_bit(&nasid_mask_long, BITS_PER_LONG,
b + 1);
} while (b < BITS_PER_LONG);
}
return n_IRQs_detected;
}
static void
xpc_process_activate_IRQ_rcvd_sn2(void)
{
unsigned long irq_flags;
int n_IRQs_expected;
int n_IRQs_detected;
spin_lock_irqsave(&xpc_activate_IRQ_rcvd_lock, irq_flags);
n_IRQs_expected = xpc_activate_IRQ_rcvd;
xpc_activate_IRQ_rcvd = 0;
spin_unlock_irqrestore(&xpc_activate_IRQ_rcvd_lock, irq_flags);
n_IRQs_detected = xpc_identify_activate_IRQ_sender_sn2();
if (n_IRQs_detected < n_IRQs_expected) {
/* retry once to help avoid missing amo */
(void)xpc_identify_activate_IRQ_sender_sn2();
}
}
/*
* Setup the channel structures that are sn2 specific.
*/
static enum xp_retval
xpc_setup_ch_structures_sn2(struct xpc_partition *part)
{
struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
struct xpc_channel_sn2 *ch_sn2;
enum xp_retval retval;
int ret;
int cpuid;
int ch_number;
struct timer_list *timer;
short partid = XPC_PARTID(part);
/* allocate all the required GET/PUT values */
part_sn2->local_GPs =
xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE, GFP_KERNEL,
&part_sn2->local_GPs_base);
if (part_sn2->local_GPs == NULL) {
dev_err(xpc_chan, "can't get memory for local get/put "
"values\n");
return xpNoMemory;
}
part_sn2->remote_GPs =
xpc_kzalloc_cacheline_aligned(XPC_GP_SIZE, GFP_KERNEL,
&part_sn2->remote_GPs_base);
if (part_sn2->remote_GPs == NULL) {
dev_err(xpc_chan, "can't get memory for remote get/put "
"values\n");
retval = xpNoMemory;
goto out_1;
}
part_sn2->remote_GPs_pa = 0;
/* allocate all the required open and close args */
part_sn2->local_openclose_args =
xpc_kzalloc_cacheline_aligned(XPC_OPENCLOSE_ARGS_SIZE,
GFP_KERNEL, &part_sn2->
local_openclose_args_base);
if (part_sn2->local_openclose_args == NULL) {
dev_err(xpc_chan, "can't get memory for local connect args\n");
retval = xpNoMemory;
goto out_2;
}
part_sn2->remote_openclose_args_pa = 0;
part_sn2->local_chctl_amo_va = xpc_init_IRQ_amo_sn2(partid);
part_sn2->notify_IRQ_nasid = 0;
part_sn2->notify_IRQ_phys_cpuid = 0;
part_sn2->remote_chctl_amo_va = NULL;
sprintf(part_sn2->notify_IRQ_owner, "xpc%02d", partid);
ret = request_irq(SGI_XPC_NOTIFY, xpc_handle_notify_IRQ_sn2,
IRQF_SHARED, part_sn2->notify_IRQ_owner,
(void *)(u64)partid);
if (ret != 0) {
dev_err(xpc_chan, "can't register NOTIFY IRQ handler, "
"errno=%d\n", -ret);
retval = xpLackOfResources;
goto out_3;
}
/* Setup a timer to check for dropped notify IRQs */
timer = &part_sn2->dropped_notify_IRQ_timer;
init_timer(timer);
timer->function =
(void (*)(unsigned long))xpc_check_for_dropped_notify_IRQ_sn2;
timer->data = (unsigned long)part;
timer->expires = jiffies + XPC_DROPPED_NOTIFY_IRQ_WAIT_INTERVAL;
add_timer(timer);
for (ch_number = 0; ch_number < part->nchannels; ch_number++) {
ch_sn2 = &part->channels[ch_number].sn.sn2;
ch_sn2->local_GP = &part_sn2->local_GPs[ch_number];
ch_sn2->local_openclose_args =
&part_sn2->local_openclose_args[ch_number];
mutex_init(&ch_sn2->msg_to_pull_mutex);
}
/*
* Setup the per partition specific variables required by the
* remote partition to establish channel connections with us.
*
* The setting of the magic # indicates that these per partition
* specific variables are ready to be used.
*/
xpc_vars_part_sn2[partid].GPs_pa = xp_pa(part_sn2->local_GPs);
xpc_vars_part_sn2[partid].openclose_args_pa =
xp_pa(part_sn2->local_openclose_args);
xpc_vars_part_sn2[partid].chctl_amo_pa =
xp_pa(part_sn2->local_chctl_amo_va);
cpuid = raw_smp_processor_id(); /* any CPU in this partition will do */
xpc_vars_part_sn2[partid].notify_IRQ_nasid = cpuid_to_nasid(cpuid);
xpc_vars_part_sn2[partid].notify_IRQ_phys_cpuid =
cpu_physical_id(cpuid);
xpc_vars_part_sn2[partid].nchannels = part->nchannels;
xpc_vars_part_sn2[partid].magic = XPC_VP_MAGIC1_SN2;
return xpSuccess;
/* setup of ch structures failed */
out_3:
kfree(part_sn2->local_openclose_args_base);
part_sn2->local_openclose_args = NULL;
out_2:
kfree(part_sn2->remote_GPs_base);
part_sn2->remote_GPs = NULL;
out_1:
kfree(part_sn2->local_GPs_base);
part_sn2->local_GPs = NULL;
return retval;
}
/*
* Teardown the channel structures that are sn2 specific.
*/
static void
xpc_teardown_ch_structures_sn2(struct xpc_partition *part)
{
struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
short partid = XPC_PARTID(part);
/*
* Indicate that the variables specific to the remote partition are no
* longer available for its use.
*/
xpc_vars_part_sn2[partid].magic = 0;
/* in case we've still got outstanding timers registered... */
del_timer_sync(&part_sn2->dropped_notify_IRQ_timer);
free_irq(SGI_XPC_NOTIFY, (void *)(u64)partid);
kfree(part_sn2->local_openclose_args_base);
part_sn2->local_openclose_args = NULL;
kfree(part_sn2->remote_GPs_base);
part_sn2->remote_GPs = NULL;
kfree(part_sn2->local_GPs_base);
part_sn2->local_GPs = NULL;
part_sn2->local_chctl_amo_va = NULL;
}
/*
* Create a wrapper that hides the underlying mechanism for pulling a cacheline
* (or multiple cachelines) from a remote partition.
*
* src_pa must be a cacheline aligned physical address on the remote partition.
* dst must be a cacheline aligned virtual address on this partition.
* cnt must be cacheline sized
*/
/* ??? Replace this function by call to xp_remote_memcpy() or bte_copy()? */
static enum xp_retval
xpc_pull_remote_cachelines_sn2(struct xpc_partition *part, void *dst,
const unsigned long src_pa, size_t cnt)
{
enum xp_retval ret;
DBUG_ON(src_pa != L1_CACHE_ALIGN(src_pa));
DBUG_ON((unsigned long)dst != L1_CACHE_ALIGN((unsigned long)dst));
DBUG_ON(cnt != L1_CACHE_ALIGN(cnt));
if (part->act_state == XPC_P_AS_DEACTIVATING)
return part->reason;
ret = xp_remote_memcpy(xp_pa(dst), src_pa, cnt);
if (ret != xpSuccess) {
dev_dbg(xpc_chan, "xp_remote_memcpy() from partition %d failed,"
" ret=%d\n", XPC_PARTID(part), ret);
}
return ret;
}
/*
* Pull the remote per partition specific variables from the specified
* partition.
*/
static enum xp_retval
xpc_pull_remote_vars_part_sn2(struct xpc_partition *part)
{
struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
u8 buffer[L1_CACHE_BYTES * 2];
struct xpc_vars_part_sn2 *pulled_entry_cacheline =
(struct xpc_vars_part_sn2 *)L1_CACHE_ALIGN((u64)buffer);
struct xpc_vars_part_sn2 *pulled_entry;
unsigned long remote_entry_cacheline_pa;
unsigned long remote_entry_pa;
short partid = XPC_PARTID(part);
enum xp_retval ret;
/* pull the cacheline that contains the variables we're interested in */
DBUG_ON(part_sn2->remote_vars_part_pa !=
L1_CACHE_ALIGN(part_sn2->remote_vars_part_pa));
DBUG_ON(sizeof(struct xpc_vars_part_sn2) != L1_CACHE_BYTES / 2);
remote_entry_pa = part_sn2->remote_vars_part_pa +
sn_partition_id * sizeof(struct xpc_vars_part_sn2);
remote_entry_cacheline_pa = (remote_entry_pa & ~(L1_CACHE_BYTES - 1));
pulled_entry = (struct xpc_vars_part_sn2 *)((u64)pulled_entry_cacheline
+ (remote_entry_pa &
(L1_CACHE_BYTES - 1)));
ret = xpc_pull_remote_cachelines_sn2(part, pulled_entry_cacheline,
remote_entry_cacheline_pa,
L1_CACHE_BYTES);
if (ret != xpSuccess) {
dev_dbg(xpc_chan, "failed to pull XPC vars_part from "
"partition %d, ret=%d\n", partid, ret);
return ret;
}
/* see if they've been set up yet */
if (pulled_entry->magic != XPC_VP_MAGIC1_SN2 &&
pulled_entry->magic != XPC_VP_MAGIC2_SN2) {
if (pulled_entry->magic != 0) {
dev_dbg(xpc_chan, "partition %d's XPC vars_part for "
"partition %d has bad magic value (=0x%llx)\n",
partid, sn_partition_id, pulled_entry->magic);
return xpBadMagic;
}
/* they've not been initialized yet */
return xpRetry;
}
if (xpc_vars_part_sn2[partid].magic == XPC_VP_MAGIC1_SN2) {
/* validate the variables */
if (pulled_entry->GPs_pa == 0 ||
pulled_entry->openclose_args_pa == 0 ||
pulled_entry->chctl_amo_pa == 0) {
dev_err(xpc_chan, "partition %d's XPC vars_part for "
"partition %d are not valid\n", partid,
sn_partition_id);
return xpInvalidAddress;
}
/* the variables we imported look to be valid */
part_sn2->remote_GPs_pa = pulled_entry->GPs_pa;
part_sn2->remote_openclose_args_pa =
pulled_entry->openclose_args_pa;
part_sn2->remote_chctl_amo_va =
(struct amo *)__va(pulled_entry->chctl_amo_pa);
part_sn2->notify_IRQ_nasid = pulled_entry->notify_IRQ_nasid;
part_sn2->notify_IRQ_phys_cpuid =
pulled_entry->notify_IRQ_phys_cpuid;
if (part->nchannels > pulled_entry->nchannels)
part->nchannels = pulled_entry->nchannels;
/* let the other side know that we've pulled their variables */
xpc_vars_part_sn2[partid].magic = XPC_VP_MAGIC2_SN2;
}
if (pulled_entry->magic == XPC_VP_MAGIC1_SN2)
return xpRetry;
return xpSuccess;
}
/*
* Establish first contact with the remote partititon. This involves pulling
* the XPC per partition variables from the remote partition and waiting for
* the remote partition to pull ours.
*/
static enum xp_retval
xpc_make_first_contact_sn2(struct xpc_partition *part)
{
struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
enum xp_retval ret;
/*
* Register the remote partition's amos with SAL so it can handle
* and cleanup errors within that address range should the remote
* partition go down. We don't unregister this range because it is
* difficult to tell when outstanding writes to the remote partition
* are finished and thus when it is safe to unregister. This should
* not result in wasted space in the SAL xp_addr_region table because
* we should get the same page for remote_amos_page_pa after module
* reloads and system reboots.
*/
if (sn_register_xp_addr_region(part_sn2->remote_amos_page_pa,
PAGE_SIZE, 1) < 0) {
dev_warn(xpc_part, "xpc_activating(%d) failed to register "
"xp_addr region\n", XPC_PARTID(part));
ret = xpPhysAddrRegFailed;
XPC_DEACTIVATE_PARTITION(part, ret);
return ret;
}
/*
* Send activate IRQ to get other side to activate if they've not
* already begun to do so.
*/
xpc_send_activate_IRQ_sn2(part_sn2->remote_amos_page_pa,
cnodeid_to_nasid(0),
part_sn2->activate_IRQ_nasid,
part_sn2->activate_IRQ_phys_cpuid);
while ((ret = xpc_pull_remote_vars_part_sn2(part)) != xpSuccess) {
if (ret != xpRetry) {
XPC_DEACTIVATE_PARTITION(part, ret);
return ret;
}
dev_dbg(xpc_part, "waiting to make first contact with "
"partition %d\n", XPC_PARTID(part));
/* wait a 1/4 of a second or so */
(void)msleep_interruptible(250);
if (part->act_state == XPC_P_AS_DEACTIVATING)
return part->reason;
}
return xpSuccess;
}
/*
* Get the chctl flags and pull the openclose args and/or remote GPs as needed.
*/
static u64
xpc_get_chctl_all_flags_sn2(struct xpc_partition *part)
{
struct xpc_partition_sn2 *part_sn2 = &part->sn.sn2;
unsigned long irq_flags;
union xpc_channel_ctl_flags chctl;
enum xp_retval ret;
/*
* See if there are any chctl flags to be handled.
*/
spin_lock_irqsave(&part->chctl_lock, irq_flags);
chctl = part->chctl;
if (chctl.all_flags != 0)
part->chctl.all_flags = 0;
spin_unlock_irqrestore(&part->chctl_lock, irq_flags);
if (xpc_any_openclose_chctl_flags_set(&chctl)) {
ret = xpc_pull_remote_cachelines_sn2(part, part->
remote_openclose_args,
part_sn2->
remote_openclose_args_pa,
XPC_OPENCLOSE_ARGS_SIZE);
if (ret != xpSuccess) {
XPC_DEACTIVATE_PARTITION(part, ret);
dev_dbg(xpc_chan, "failed to pull openclose args from "
"partition %d, ret=%d\n", XPC_PARTID(part),
ret);
/* don't bother processing chctl flags anymore */
chctl.all_flags = 0;
}
}
if (xpc_any_msg_chctl_flags_set(&chctl)) {
ret = xpc_pull_remote_cachelines_sn2(part, part_sn2->remote_GPs,
part_sn2->remote_GPs_pa,
XPC_GP_SIZE);
if (ret != xpSuccess) {
XPC_DEACTIVATE_PARTITION(part, ret);
dev_dbg(xpc_chan, "failed to pull GPs from partition "
"%d, ret=%d\n", XPC_PARTID(part), ret);
/* don't bother processing chctl flags anymore */
chctl.all_flags = 0;
}
}
return chctl.all_flags;
}
/*
* Allocate the local message queue and the notify queue.
*/
static enum xp_retval
xpc_allocate_local_msgqueue_sn2(struct xpc_channel *ch)
{
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
unsigned long irq_flags;
int nentries;
size_t nbytes;
for (nentries = ch->local_nentries; nentries > 0; nentries--) {
nbytes = nentries * ch->entry_size;
ch_sn2->local_msgqueue =
xpc_kzalloc_cacheline_aligned(nbytes, GFP_KERNEL,
&ch_sn2->local_msgqueue_base);
if (ch_sn2->local_msgqueue == NULL)
continue;
nbytes = nentries * sizeof(struct xpc_notify_sn2);
ch_sn2->notify_queue = kzalloc(nbytes, GFP_KERNEL);
if (ch_sn2->notify_queue == NULL) {
kfree(ch_sn2->local_msgqueue_base);
ch_sn2->local_msgqueue = NULL;
continue;
}
spin_lock_irqsave(&ch->lock, irq_flags);
if (nentries < ch->local_nentries) {
dev_dbg(xpc_chan, "nentries=%d local_nentries=%d, "
"partid=%d, channel=%d\n", nentries,
ch->local_nentries, ch->partid, ch->number);
ch->local_nentries = nentries;
}
spin_unlock_irqrestore(&ch->lock, irq_flags);
return xpSuccess;
}
dev_dbg(xpc_chan, "can't get memory for local message queue and notify "
"queue, partid=%d, channel=%d\n", ch->partid, ch->number);
return xpNoMemory;
}
/*
* Allocate the cached remote message queue.
*/
static enum xp_retval
xpc_allocate_remote_msgqueue_sn2(struct xpc_channel *ch)
{
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
unsigned long irq_flags;
int nentries;
size_t nbytes;
DBUG_ON(ch->remote_nentries <= 0);
for (nentries = ch->remote_nentries; nentries > 0; nentries--) {
nbytes = nentries * ch->entry_size;
ch_sn2->remote_msgqueue =
xpc_kzalloc_cacheline_aligned(nbytes, GFP_KERNEL, &ch_sn2->
remote_msgqueue_base);
if (ch_sn2->remote_msgqueue == NULL)
continue;
spin_lock_irqsave(&ch->lock, irq_flags);
if (nentries < ch->remote_nentries) {
dev_dbg(xpc_chan, "nentries=%d remote_nentries=%d, "
"partid=%d, channel=%d\n", nentries,
ch->remote_nentries, ch->partid, ch->number);
ch->remote_nentries = nentries;
}
spin_unlock_irqrestore(&ch->lock, irq_flags);
return xpSuccess;
}
dev_dbg(xpc_chan, "can't get memory for cached remote message queue, "
"partid=%d, channel=%d\n", ch->partid, ch->number);
return xpNoMemory;
}
/*
* Allocate message queues and other stuff associated with a channel.
*
* Note: Assumes all of the channel sizes are filled in.
*/
static enum xp_retval
xpc_setup_msg_structures_sn2(struct xpc_channel *ch)
{
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
enum xp_retval ret;
DBUG_ON(ch->flags & XPC_C_SETUP);
ret = xpc_allocate_local_msgqueue_sn2(ch);
if (ret == xpSuccess) {
ret = xpc_allocate_remote_msgqueue_sn2(ch);
if (ret != xpSuccess) {
kfree(ch_sn2->local_msgqueue_base);
ch_sn2->local_msgqueue = NULL;
kfree(ch_sn2->notify_queue);
ch_sn2->notify_queue = NULL;
}
}
return ret;
}
/*
* Free up message queues and other stuff that were allocated for the specified
* channel.
*/
static void
xpc_teardown_msg_structures_sn2(struct xpc_channel *ch)
{
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
DBUG_ON(!spin_is_locked(&ch->lock));
ch_sn2->remote_msgqueue_pa = 0;
ch_sn2->local_GP->get = 0;
ch_sn2->local_GP->put = 0;
ch_sn2->remote_GP.get = 0;
ch_sn2->remote_GP.put = 0;
ch_sn2->w_local_GP.get = 0;
ch_sn2->w_local_GP.put = 0;
ch_sn2->w_remote_GP.get = 0;
ch_sn2->w_remote_GP.put = 0;
ch_sn2->next_msg_to_pull = 0;
if (ch->flags & XPC_C_SETUP) {
dev_dbg(xpc_chan, "ch->flags=0x%x, partid=%d, channel=%d\n",
ch->flags, ch->partid, ch->number);
kfree(ch_sn2->local_msgqueue_base);
ch_sn2->local_msgqueue = NULL;
kfree(ch_sn2->remote_msgqueue_base);
ch_sn2->remote_msgqueue = NULL;
kfree(ch_sn2->notify_queue);
ch_sn2->notify_queue = NULL;
}
}
/*
* Notify those who wanted to be notified upon delivery of their message.
*/
static void
xpc_notify_senders_sn2(struct xpc_channel *ch, enum xp_retval reason, s64 put)
{
struct xpc_notify_sn2 *notify;
u8 notify_type;
s64 get = ch->sn.sn2.w_remote_GP.get - 1;
while (++get < put && atomic_read(&ch->n_to_notify) > 0) {
notify = &ch->sn.sn2.notify_queue[get % ch->local_nentries];
/*
* See if the notify entry indicates it was associated with
* a message who's sender wants to be notified. It is possible
* that it is, but someone else is doing or has done the
* notification.
*/
notify_type = notify->type;
if (notify_type == 0 ||
cmpxchg(&notify->type, notify_type, 0) != notify_type) {
continue;
}
DBUG_ON(notify_type != XPC_N_CALL);
atomic_dec(&ch->n_to_notify);
if (notify->func != NULL) {
dev_dbg(xpc_chan, "notify->func() called, notify=0x%p "
"msg_number=%lld partid=%d channel=%d\n",
(void *)notify, get, ch->partid, ch->number);
notify->func(reason, ch->partid, ch->number,
notify->key);
dev_dbg(xpc_chan, "notify->func() returned, notify=0x%p"
" msg_number=%lld partid=%d channel=%d\n",
(void *)notify, get, ch->partid, ch->number);
}
}
}
static void
xpc_notify_senders_of_disconnect_sn2(struct xpc_channel *ch)
{
xpc_notify_senders_sn2(ch, ch->reason, ch->sn.sn2.w_local_GP.put);
}
/*
* Clear some of the msg flags in the local message queue.
*/
static inline void
xpc_clear_local_msgqueue_flags_sn2(struct xpc_channel *ch)
{
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
struct xpc_msg_sn2 *msg;
s64 get;
get = ch_sn2->w_remote_GP.get;
do {
msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
(get % ch->local_nentries) *
ch->entry_size);
DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
msg->flags = 0;
} while (++get < ch_sn2->remote_GP.get);
}
/*
* Clear some of the msg flags in the remote message queue.
*/
static inline void
xpc_clear_remote_msgqueue_flags_sn2(struct xpc_channel *ch)
{
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
struct xpc_msg_sn2 *msg;
s64 put, remote_nentries = ch->remote_nentries;
/* flags are zeroed when the buffer is allocated */
if (ch_sn2->remote_GP.put < remote_nentries)
return;
put = max(ch_sn2->w_remote_GP.put, remote_nentries);
do {
msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
(put % remote_nentries) *
ch->entry_size);
DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
DBUG_ON(!(msg->flags & XPC_M_SN2_DONE));
DBUG_ON(msg->number != put - remote_nentries);
msg->flags = 0;
} while (++put < ch_sn2->remote_GP.put);
}
static int
xpc_n_of_deliverable_payloads_sn2(struct xpc_channel *ch)
{
return ch->sn.sn2.w_remote_GP.put - ch->sn.sn2.w_local_GP.get;
}
static void
xpc_process_msg_chctl_flags_sn2(struct xpc_partition *part, int ch_number)
{
struct xpc_channel *ch = &part->channels[ch_number];
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
int npayloads_sent;
ch_sn2->remote_GP = part->sn.sn2.remote_GPs[ch_number];
/* See what, if anything, has changed for each connected channel */
xpc_msgqueue_ref(ch);
if (ch_sn2->w_remote_GP.get == ch_sn2->remote_GP.get &&
ch_sn2->w_remote_GP.put == ch_sn2->remote_GP.put) {
/* nothing changed since GPs were last pulled */
xpc_msgqueue_deref(ch);
return;
}
if (!(ch->flags & XPC_C_CONNECTED)) {
xpc_msgqueue_deref(ch);
return;
}
/*
* First check to see if messages recently sent by us have been
* received by the other side. (The remote GET value will have
* changed since we last looked at it.)
*/
if (ch_sn2->w_remote_GP.get != ch_sn2->remote_GP.get) {
/*
* We need to notify any senders that want to be notified
* that their sent messages have been received by their
* intended recipients. We need to do this before updating
* w_remote_GP.get so that we don't allocate the same message
* queue entries prematurely (see xpc_allocate_msg()).
*/
if (atomic_read(&ch->n_to_notify) > 0) {
/*
* Notify senders that messages sent have been
* received and delivered by the other side.
*/
xpc_notify_senders_sn2(ch, xpMsgDelivered,
ch_sn2->remote_GP.get);
}
/*
* Clear msg->flags in previously sent messages, so that
* they're ready for xpc_allocate_msg().
*/
xpc_clear_local_msgqueue_flags_sn2(ch);
ch_sn2->w_remote_GP.get = ch_sn2->remote_GP.get;
dev_dbg(xpc_chan, "w_remote_GP.get changed to %lld, partid=%d, "
"channel=%d\n", ch_sn2->w_remote_GP.get, ch->partid,
ch->number);
/*
* If anyone was waiting for message queue entries to become
* available, wake them up.
*/
if (atomic_read(&ch->n_on_msg_allocate_wq) > 0)
wake_up(&ch->msg_allocate_wq);
}
/*
* Now check for newly sent messages by the other side. (The remote
* PUT value will have changed since we last looked at it.)
*/
if (ch_sn2->w_remote_GP.put != ch_sn2->remote_GP.put) {
/*
* Clear msg->flags in previously received messages, so that
* they're ready for xpc_get_deliverable_payload_sn2().
*/
xpc_clear_remote_msgqueue_flags_sn2(ch);
smp_wmb(); /* ensure flags have been cleared before bte_copy */
ch_sn2->w_remote_GP.put = ch_sn2->remote_GP.put;
dev_dbg(xpc_chan, "w_remote_GP.put changed to %lld, partid=%d, "
"channel=%d\n", ch_sn2->w_remote_GP.put, ch->partid,
ch->number);
npayloads_sent = xpc_n_of_deliverable_payloads_sn2(ch);
if (npayloads_sent > 0) {
dev_dbg(xpc_chan, "msgs waiting to be copied and "
"delivered=%d, partid=%d, channel=%d\n",
npayloads_sent, ch->partid, ch->number);
if (ch->flags & XPC_C_CONNECTEDCALLOUT_MADE)
xpc_activate_kthreads(ch, npayloads_sent);
}
}
xpc_msgqueue_deref(ch);
}
static struct xpc_msg_sn2 *
xpc_pull_remote_msg_sn2(struct xpc_channel *ch, s64 get)
{
struct xpc_partition *part = &xpc_partitions[ch->partid];
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
unsigned long remote_msg_pa;
struct xpc_msg_sn2 *msg;
u32 msg_index;
u32 nmsgs;
u64 msg_offset;
enum xp_retval ret;
if (mutex_lock_interruptible(&ch_sn2->msg_to_pull_mutex) != 0) {
/* we were interrupted by a signal */
return NULL;
}
while (get >= ch_sn2->next_msg_to_pull) {
/* pull as many messages as are ready and able to be pulled */
msg_index = ch_sn2->next_msg_to_pull % ch->remote_nentries;
DBUG_ON(ch_sn2->next_msg_to_pull >= ch_sn2->w_remote_GP.put);
nmsgs = ch_sn2->w_remote_GP.put - ch_sn2->next_msg_to_pull;
if (msg_index + nmsgs > ch->remote_nentries) {
/* ignore the ones that wrap the msg queue for now */
nmsgs = ch->remote_nentries - msg_index;
}
msg_offset = msg_index * ch->entry_size;
msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue +
msg_offset);
remote_msg_pa = ch_sn2->remote_msgqueue_pa + msg_offset;
ret = xpc_pull_remote_cachelines_sn2(part, msg, remote_msg_pa,
nmsgs * ch->entry_size);
if (ret != xpSuccess) {
dev_dbg(xpc_chan, "failed to pull %d msgs starting with"
" msg %lld from partition %d, channel=%d, "
"ret=%d\n", nmsgs, ch_sn2->next_msg_to_pull,
ch->partid, ch->number, ret);
XPC_DEACTIVATE_PARTITION(part, ret);
mutex_unlock(&ch_sn2->msg_to_pull_mutex);
return NULL;
}
ch_sn2->next_msg_to_pull += nmsgs;
}
mutex_unlock(&ch_sn2->msg_to_pull_mutex);
/* return the message we were looking for */
msg_offset = (get % ch->remote_nentries) * ch->entry_size;
msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->remote_msgqueue + msg_offset);
return msg;
}
/*
* Get the next deliverable message's payload.
*/
static void *
xpc_get_deliverable_payload_sn2(struct xpc_channel *ch)
{
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
struct xpc_msg_sn2 *msg;
void *payload = NULL;
s64 get;
do {
if (ch->flags & XPC_C_DISCONNECTING)
break;
get = ch_sn2->w_local_GP.get;
smp_rmb(); /* guarantee that .get loads before .put */
if (get == ch_sn2->w_remote_GP.put)
break;
/* There are messages waiting to be pulled and delivered.
* We need to try to secure one for ourselves. We'll do this
* by trying to increment w_local_GP.get and hope that no one
* else beats us to it. If they do, we'll we'll simply have
* to try again for the next one.
*/
if (cmpxchg(&ch_sn2->w_local_GP.get, get, get + 1) == get) {
/* we got the entry referenced by get */
dev_dbg(xpc_chan, "w_local_GP.get changed to %lld, "
"partid=%d, channel=%d\n", get + 1,
ch->partid, ch->number);
/* pull the message from the remote partition */
msg = xpc_pull_remote_msg_sn2(ch, get);
if (msg != NULL) {
DBUG_ON(msg->number != get);
DBUG_ON(msg->flags & XPC_M_SN2_DONE);
DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
payload = &msg->payload;
}
break;
}
} while (1);
return payload;
}
/*
* Now we actually send the messages that are ready to be sent by advancing
* the local message queue's Put value and then send a chctl msgrequest to the
* recipient partition.
*/
static void
xpc_send_msgs_sn2(struct xpc_channel *ch, s64 initial_put)
{
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
struct xpc_msg_sn2 *msg;
s64 put = initial_put + 1;
int send_msgrequest = 0;
while (1) {
while (1) {
if (put == ch_sn2->w_local_GP.put)
break;
msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->
local_msgqueue + (put %
ch->local_nentries) *
ch->entry_size);
if (!(msg->flags & XPC_M_SN2_READY))
break;
put++;
}
if (put == initial_put) {
/* nothing's changed */
break;
}
if (cmpxchg_rel(&ch_sn2->local_GP->put, initial_put, put) !=
initial_put) {
/* someone else beat us to it */
DBUG_ON(ch_sn2->local_GP->put < initial_put);
break;
}
/* we just set the new value of local_GP->put */
dev_dbg(xpc_chan, "local_GP->put changed to %lld, partid=%d, "
"channel=%d\n", put, ch->partid, ch->number);
send_msgrequest = 1;
/*
* We need to ensure that the message referenced by
* local_GP->put is not XPC_M_SN2_READY or that local_GP->put
* equals w_local_GP.put, so we'll go have a look.
*/
initial_put = put;
}
if (send_msgrequest)
xpc_send_chctl_msgrequest_sn2(ch);
}
/*
* Allocate an entry for a message from the message queue associated with the
* specified channel.
*/
static enum xp_retval
xpc_allocate_msg_sn2(struct xpc_channel *ch, u32 flags,
struct xpc_msg_sn2 **address_of_msg)
{
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
struct xpc_msg_sn2 *msg;
enum xp_retval ret;
s64 put;
/*
* Get the next available message entry from the local message queue.
* If none are available, we'll make sure that we grab the latest
* GP values.
*/
ret = xpTimeout;
while (1) {
put = ch_sn2->w_local_GP.put;
smp_rmb(); /* guarantee that .put loads before .get */
if (put - ch_sn2->w_remote_GP.get < ch->local_nentries) {
/* There are available message entries. We need to try
* to secure one for ourselves. We'll do this by trying
* to increment w_local_GP.put as long as someone else
* doesn't beat us to it. If they do, we'll have to
* try again.
*/
if (cmpxchg(&ch_sn2->w_local_GP.put, put, put + 1) ==
put) {
/* we got the entry referenced by put */
break;
}
continue; /* try again */
}
/*
* There aren't any available msg entries at this time.
*
* In waiting for a message entry to become available,
* we set a timeout in case the other side is not sending
* completion interrupts. This lets us fake a notify IRQ
* that will cause the notify IRQ handler to fetch the latest
* GP values as if an interrupt was sent by the other side.
*/
if (ret == xpTimeout)
xpc_send_chctl_local_msgrequest_sn2(ch);
if (flags & XPC_NOWAIT)
return xpNoWait;
ret = xpc_allocate_msg_wait(ch);
if (ret != xpInterrupted && ret != xpTimeout)
return ret;
}
/* get the message's address and initialize it */
msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->local_msgqueue +
(put % ch->local_nentries) *
ch->entry_size);
DBUG_ON(msg->flags != 0);
msg->number = put;
dev_dbg(xpc_chan, "w_local_GP.put changed to %lld; msg=0x%p, "
"msg_number=%lld, partid=%d, channel=%d\n", put + 1,
(void *)msg, msg->number, ch->partid, ch->number);
*address_of_msg = msg;
return xpSuccess;
}
/*
* Common code that does the actual sending of the message by advancing the
* local message queue's Put value and sends a chctl msgrequest to the
* partition the message is being sent to.
*/
static enum xp_retval
xpc_send_payload_sn2(struct xpc_channel *ch, u32 flags, void *payload,
u16 payload_size, u8 notify_type, xpc_notify_func func,
void *key)
{
enum xp_retval ret = xpSuccess;
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
struct xpc_msg_sn2 *msg = msg;
struct xpc_notify_sn2 *notify = notify;
s64 msg_number;
s64 put;
DBUG_ON(notify_type == XPC_N_CALL && func == NULL);
if (XPC_MSG_SIZE(payload_size) > ch->entry_size)
return xpPayloadTooBig;
xpc_msgqueue_ref(ch);
if (ch->flags & XPC_C_DISCONNECTING) {
ret = ch->reason;
goto out_1;
}
if (!(ch->flags & XPC_C_CONNECTED)) {
ret = xpNotConnected;
goto out_1;
}
ret = xpc_allocate_msg_sn2(ch, flags, &msg);
if (ret != xpSuccess)
goto out_1;
msg_number = msg->number;
if (notify_type != 0) {
/*
* Tell the remote side to send an ACK interrupt when the
* message has been delivered.
*/
msg->flags |= XPC_M_SN2_INTERRUPT;
atomic_inc(&ch->n_to_notify);
notify = &ch_sn2->notify_queue[msg_number % ch->local_nentries];
notify->func = func;
notify->key = key;
notify->type = notify_type;
/* ??? Is a mb() needed here? */
if (ch->flags & XPC_C_DISCONNECTING) {
/*
* An error occurred between our last error check and
* this one. We will try to clear the type field from
* the notify entry. If we succeed then
* xpc_disconnect_channel() didn't already process
* the notify entry.
*/
if (cmpxchg(&notify->type, notify_type, 0) ==
notify_type) {
atomic_dec(&ch->n_to_notify);
ret = ch->reason;
}
goto out_1;
}
}
memcpy(&msg->payload, payload, payload_size);
msg->flags |= XPC_M_SN2_READY;
/*
* The preceding store of msg->flags must occur before the following
* load of local_GP->put.
*/
smp_mb();
/* see if the message is next in line to be sent, if so send it */
put = ch_sn2->local_GP->put;
if (put == msg_number)
xpc_send_msgs_sn2(ch, put);
out_1:
xpc_msgqueue_deref(ch);
return ret;
}
/*
* Now we actually acknowledge the messages that have been delivered and ack'd
* by advancing the cached remote message queue's Get value and if requested
* send a chctl msgrequest to the message sender's partition.
*
* If a message has XPC_M_SN2_INTERRUPT set, send an interrupt to the partition
* that sent the message.
*/
static void
xpc_acknowledge_msgs_sn2(struct xpc_channel *ch, s64 initial_get, u8 msg_flags)
{
struct xpc_channel_sn2 *ch_sn2 = &ch->sn.sn2;
struct xpc_msg_sn2 *msg;
s64 get = initial_get + 1;
int send_msgrequest = 0;
while (1) {
while (1) {
if (get == ch_sn2->w_local_GP.get)
break;
msg = (struct xpc_msg_sn2 *)((u64)ch_sn2->
remote_msgqueue + (get %
ch->remote_nentries) *
ch->entry_size);
if (!(msg->flags & XPC_M_SN2_DONE))
break;
msg_flags |= msg->flags;
get++;
}
if (get == initial_get) {
/* nothing's changed */
break;
}
if (cmpxchg_rel(&ch_sn2->local_GP->get, initial_get, get) !=
initial_get) {
/* someone else beat us to it */
DBUG_ON(ch_sn2->local_GP->get <= initial_get);
break;
}
/* we just set the new value of local_GP->get */
dev_dbg(xpc_chan, "local_GP->get changed to %lld, partid=%d, "
"channel=%d\n", get, ch->partid, ch->number);
send_msgrequest = (msg_flags & XPC_M_SN2_INTERRUPT);
/*
* We need to ensure that the message referenced by
* local_GP->get is not XPC_M_SN2_DONE or that local_GP->get
* equals w_local_GP.get, so we'll go have a look.
*/
initial_get = get;
}
if (send_msgrequest)
xpc_send_chctl_msgrequest_sn2(ch);
}
static void
xpc_received_payload_sn2(struct xpc_channel *ch, void *payload)
{
struct xpc_msg_sn2 *msg;
s64 msg_number;
s64 get;
msg = container_of(payload, struct xpc_msg_sn2, payload);
msg_number = msg->number;
dev_dbg(xpc_chan, "msg=0x%p, msg_number=%lld, partid=%d, channel=%d\n",
(void *)msg, msg_number, ch->partid, ch->number);
DBUG_ON((((u64)msg - (u64)ch->sn.sn2.remote_msgqueue) / ch->entry_size) !=
msg_number % ch->remote_nentries);
DBUG_ON(!(msg->flags & XPC_M_SN2_READY));
DBUG_ON(msg->flags & XPC_M_SN2_DONE);
msg->flags |= XPC_M_SN2_DONE;
/*
* The preceding store of msg->flags must occur before the following
* load of local_GP->get.
*/
smp_mb();
/*
* See if this message is next in line to be acknowledged as having
* been delivered.
*/
get = ch->sn.sn2.local_GP->get;
if (get == msg_number)
xpc_acknowledge_msgs_sn2(ch, get, msg->flags);
}
static struct xpc_arch_operations xpc_arch_ops_sn2 = {
.setup_partitions = xpc_setup_partitions_sn2,
.teardown_partitions = xpc_teardown_partitions_sn2,
.process_activate_IRQ_rcvd = xpc_process_activate_IRQ_rcvd_sn2,
.get_partition_rsvd_page_pa = xpc_get_partition_rsvd_page_pa_sn2,
.setup_rsvd_page = xpc_setup_rsvd_page_sn2,
.allow_hb = xpc_allow_hb_sn2,
.disallow_hb = xpc_disallow_hb_sn2,
.disallow_all_hbs = xpc_disallow_all_hbs_sn2,
.increment_heartbeat = xpc_increment_heartbeat_sn2,
.offline_heartbeat = xpc_offline_heartbeat_sn2,
.online_heartbeat = xpc_online_heartbeat_sn2,
.heartbeat_init = xpc_heartbeat_init_sn2,
.heartbeat_exit = xpc_heartbeat_exit_sn2,
.get_remote_heartbeat = xpc_get_remote_heartbeat_sn2,
.request_partition_activation =
xpc_request_partition_activation_sn2,
.request_partition_reactivation =
xpc_request_partition_reactivation_sn2,
.request_partition_deactivation =
xpc_request_partition_deactivation_sn2,
.cancel_partition_deactivation_request =
xpc_cancel_partition_deactivation_request_sn2,
.setup_ch_structures = xpc_setup_ch_structures_sn2,
.teardown_ch_structures = xpc_teardown_ch_structures_sn2,
.make_first_contact = xpc_make_first_contact_sn2,
.get_chctl_all_flags = xpc_get_chctl_all_flags_sn2,
.send_chctl_closerequest = xpc_send_chctl_closerequest_sn2,
.send_chctl_closereply = xpc_send_chctl_closereply_sn2,
.send_chctl_openrequest = xpc_send_chctl_openrequest_sn2,
.send_chctl_openreply = xpc_send_chctl_openreply_sn2,
.send_chctl_opencomplete = xpc_send_chctl_opencomplete_sn2,
.process_msg_chctl_flags = xpc_process_msg_chctl_flags_sn2,
.save_remote_msgqueue_pa = xpc_save_remote_msgqueue_pa_sn2,
.setup_msg_structures = xpc_setup_msg_structures_sn2,
.teardown_msg_structures = xpc_teardown_msg_structures_sn2,
.indicate_partition_engaged = xpc_indicate_partition_engaged_sn2,
.indicate_partition_disengaged = xpc_indicate_partition_disengaged_sn2,
.partition_engaged = xpc_partition_engaged_sn2,
.any_partition_engaged = xpc_any_partition_engaged_sn2,
.assume_partition_disengaged = xpc_assume_partition_disengaged_sn2,
.n_of_deliverable_payloads = xpc_n_of_deliverable_payloads_sn2,
.send_payload = xpc_send_payload_sn2,
.get_deliverable_payload = xpc_get_deliverable_payload_sn2,
.received_payload = xpc_received_payload_sn2,
.notify_senders_of_disconnect = xpc_notify_senders_of_disconnect_sn2,
};
int
xpc_init_sn2(void)
{
int ret;
size_t buf_size;
xpc_arch_ops = xpc_arch_ops_sn2;
if (offsetof(struct xpc_msg_sn2, payload) > XPC_MSG_HDR_MAX_SIZE) {
dev_err(xpc_part, "header portion of struct xpc_msg_sn2 is "
"larger than %d\n", XPC_MSG_HDR_MAX_SIZE);
return -E2BIG;
}
buf_size = max(XPC_RP_VARS_SIZE,
XPC_RP_HEADER_SIZE + XP_NASID_MASK_BYTES_SN2);
xpc_remote_copy_buffer_sn2 = xpc_kmalloc_cacheline_aligned(buf_size,
GFP_KERNEL,
&xpc_remote_copy_buffer_base_sn2);
if (xpc_remote_copy_buffer_sn2 == NULL) {
dev_err(xpc_part, "can't get memory for remote copy buffer\n");
return -ENOMEM;
}
/* open up protections for IPI and [potentially] amo operations */
xpc_allow_IPI_ops_sn2();
xpc_allow_amo_ops_shub_wars_1_1_sn2();
/*
* This is safe to do before the xpc_hb_checker thread has started
* because the handler releases a wait queue. If an interrupt is
* received before the thread is waiting, it will not go to sleep,
* but rather immediately process the interrupt.
*/
ret = request_irq(SGI_XPC_ACTIVATE, xpc_handle_activate_IRQ_sn2, 0,
"xpc hb", NULL);
if (ret != 0) {
dev_err(xpc_part, "can't register ACTIVATE IRQ handler, "
"errno=%d\n", -ret);
xpc_disallow_IPI_ops_sn2();
kfree(xpc_remote_copy_buffer_base_sn2);
}
return ret;
}
void
xpc_exit_sn2(void)
{
free_irq(SGI_XPC_ACTIVATE, NULL);
xpc_disallow_IPI_ops_sn2();
kfree(xpc_remote_copy_buffer_base_sn2);
}