From: Deb McLemore <debmc@linux.vnet.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: jk@ozlabs.org, Deb McLemore <debmc@linux.vnet.ibm.com>
Subject: [PATCH v2] powerpc/powernv: Add queue mechanism for early messages
Date: Wed, 29 Nov 2017 15:05:53 -0600 [thread overview]
Message-ID: <1511989553-16198-1-git-send-email-debmc@linux.vnet.ibm.com> (raw)
In-Reply-To: <cc9d63a2-c548-0669-4abc-f816dc99b8cc@linux.vnet.ibm.com>
Problem being solved is when issuing a BMC soft poweroff during IPL,
the poweroff was being lost so the machine would not poweroff.
Opal messages were being received before the opal-power code
registered its notifiers.
Alternatives discussed (option #3 was chosen):
1 - Have opal_message_init() explicitly call opal_power_control_init()
before it dequeues any OPAL messages (i.e. before we register the
opal-msg IRQ handler).
2 - Introduce concept of critical message types and when we register
handlers we track which message types have a registered handler,
then defer the opal-msg IRQ registration until we have a handler
registered for all the critical types.
3 - Buffering messages, if we receive a message and do not yet
have a handler for that type, store the message and replay when
a handler for that type is registered.
Signed-off-by: Deb McLemore <debmc@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/opal.c | 83 ++++++++++++++++++++++++++++++++---
1 file changed, 78 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index 65c79ec..46d7604 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -40,6 +40,16 @@
#include "powernv.h"
+#define OPAL_MSG_QUEUE_MAX 16
+
+struct opal_msg_node {
+ struct list_head list;
+ struct opal_msg msg;
+};
+
+static DEFINE_SPINLOCK(msg_list_lock);
+static LIST_HEAD(msg_list);
+
/* /sys/firmware/opal */
struct kobject *opal_kobj;
@@ -55,6 +65,8 @@ struct mcheck_recoverable_range {
u64 recover_addr;
};
+static int msg_list_size;
+
static struct mcheck_recoverable_range *mc_recoverable_range;
static int mc_recoverable_range_len;
@@ -231,6 +243,44 @@ static int __init opal_register_exception_handlers(void)
}
machine_early_initcall(powernv, opal_register_exception_handlers);
+static void queue_replay_msg(void *msg)
+{
+ struct opal_msg_node *msg_node;
+
+ if (msg_list_size < OPAL_MSG_QUEUE_MAX) {
+ msg_node = kzalloc(sizeof(*msg_node), GFP_ATOMIC);
+ if (msg_node) {
+ INIT_LIST_HEAD(&msg_node->list);
+ memcpy(&msg_node->msg, msg, sizeof(struct opal_msg));
+ list_add_tail(&msg_node->list, &msg_list);
+ msg_list_size++;
+ } else
+ pr_warn_once("message queue no memory\n");
+
+ if (msg_list_size >= OPAL_MSG_QUEUE_MAX)
+ pr_warn_once("message queue full\n");
+ }
+}
+
+static void dequeue_replay_msg(enum opal_msg_type msg_type)
+{
+ struct opal_msg_node *msg_node, *tmp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&msg_list_lock, flags);
+ list_for_each_entry_safe(msg_node, tmp, &msg_list, list) {
+ if (be32_to_cpu(msg_node->msg.msg_type) != msg_type)
+ continue;
+ atomic_notifier_call_chain(&opal_msg_notifier_head[msg_type],
+ msg_type,
+ &msg_node->msg);
+ list_del(&msg_node->list);
+ kfree(msg_node);
+ msg_list_size--;
+ }
+ spin_unlock_irqrestore(&msg_list_lock, flags);
+}
+
/*
* Opal message notifier based on message type. Allow subscribers to get
* notified for specific messgae type.
@@ -238,14 +288,25 @@ machine_early_initcall(powernv, opal_register_exception_handlers);
int opal_message_notifier_register(enum opal_msg_type msg_type,
struct notifier_block *nb)
{
+ int ret;
+
if (!nb || msg_type >= OPAL_MSG_TYPE_MAX) {
pr_warning("%s: Invalid arguments, msg_type:%d\n",
__func__, msg_type);
return -EINVAL;
}
- return atomic_notifier_chain_register(
- &opal_msg_notifier_head[msg_type], nb);
+ ret = atomic_notifier_chain_register(
+ &opal_msg_notifier_head[msg_type], nb);
+
+ if (ret)
+ return ret;
+
+ /* Replay any queued messages that came in */
+ /* prior to the notifier chain registration */
+ dequeue_replay_msg(msg_type);
+
+ return 0;
}
EXPORT_SYMBOL_GPL(opal_message_notifier_register);
@@ -259,9 +320,21 @@ EXPORT_SYMBOL_GPL(opal_message_notifier_unregister);
static void opal_message_do_notify(uint32_t msg_type, void *msg)
{
- /* notify subscribers */
- atomic_notifier_call_chain(&opal_msg_notifier_head[msg_type],
- msg_type, msg);
+ unsigned long flags;
+
+ spin_lock_irqsave(&msg_list_lock, flags);
+
+ if (opal_msg_notifier_head[msg_type].head != NULL) {
+ /* notify subscribers */
+ atomic_notifier_call_chain(&opal_msg_notifier_head[msg_type],
+ msg_type, msg);
+ } else {
+ /* Queue up the msg since no notifiers have */
+ /* registered yet for this msg_type */
+ queue_replay_msg(msg);
+ }
+
+ spin_unlock_irqrestore(&msg_list_lock, flags);
}
static void opal_handle_message(void)
--
2.7.4
next prev parent reply other threads:[~2017-11-29 21:06 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-26 14:30 [PATCH] powerpc/powernv: Add queue mechanism for early messages Deb McLemore
2017-11-28 13:30 ` Michael Ellerman
2017-11-28 15:29 ` Deb McLemore
2017-11-29 21:05 ` Deb McLemore [this message]
2018-05-16 13:35 ` [PATCH v2] " Michael Ellerman
2018-05-21 2:04 ` [PATCH v3] " Deb McLemore
2019-10-30 12:14 ` Michael Ellerman
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1511989553-16198-1-git-send-email-debmc@linux.vnet.ibm.com \
--to=debmc@linux.vnet.ibm.com \
--cc=jk@ozlabs.org \
--cc=linuxppc-dev@lists.ozlabs.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).