[PATCH v4 1/2] powerpc/powernv: Enhance opal message read interface

[PATCH v4 1/2] powerpc/powernv: Enhance opal message read interface

[Vasant Hegde]

Use "opal-msg-size" device tree property to allocate memory for "opal_msg".

Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/powernv/opal.c | 32 ++++++++++++++++++---------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index aba443be7daa..afa494849477 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -58,6 +58,8 @@ static DEFINE_SPINLOCK(opal_write_lock);
 static struct atomic_notifier_head opal_msg_notifier_head[OPAL_MSG_TYPE_MAX];
 static uint32_t opal_heartbeat;
 static struct task_struct *kopald_tsk;
+static struct opal_msg *opal_msg;
+static uint32_t opal_msg_size;
 
 void opal_configure_cores(void)
 {
@@ -271,14 +273,9 @@ static void opal_message_do_notify(uint32_t msg_type, void *msg)
 static void opal_handle_message(void)
 {
 	s64 ret;
-	/*
-	 * TODO: pre-allocate a message buffer depending on opal-msg-size
-	 * value in /proc/device-tree.
-	 */
-	static struct opal_msg msg;
 	u32 type;
 
-	ret = opal_get_msg(__pa(&msg), sizeof(msg));
+	ret = opal_get_msg(__pa(opal_msg), opal_msg_size);
 	/* No opal message pending. */
 	if (ret == OPAL_RESOURCE)
 		return;
@@ -290,14 +287,14 @@ static void opal_handle_message(void)
 		return;
 	}
 
-	type = be32_to_cpu(msg.msg_type);
+	type = be32_to_cpu(opal_msg->msg_type);
 
 	/* Sanity check */
 	if (type >= OPAL_MSG_TYPE_MAX) {
 		pr_warn_once("%s: Unknown message type: %u\n", __func__, type);
 		return;
 	}
-	opal_message_do_notify(type, (void *)&msg);
+	opal_message_do_notify(type, (void *)opal_msg);
 }
 
 static irqreturn_t opal_message_notify(int irq, void *data)
@@ -306,10 +303,25 @@ static irqreturn_t opal_message_notify(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static int __init opal_message_init(void)
+static int __init opal_message_init(struct device_node *opal_node)
 {
 	int ret, i, irq;
 
+	ret = of_property_read_u32(opal_node, "opal-msg-size", &opal_msg_size);
+	if (ret) {
+		pr_notice("%s: Failed to read opal-msg-size property\n",
+			  __func__);
+		opal_msg_size = sizeof(struct opal_msg);
+	}
+
+	opal_msg = kmalloc(opal_msg_size, GFP_KERNEL);
+	if (!opal_msg) {
+		opal_msg_size = sizeof(struct opal_msg);
+		/* Try to allocate fixed message size */
+		opal_msg = kmalloc(opal_msg_size, GFP_KERNEL);
+		BUG_ON(opal_msg == NULL);
+	}
+
 	for (i = 0; i < OPAL_MSG_TYPE_MAX; i++)
 		ATOMIC_INIT_NOTIFIER_HEAD(&opal_msg_notifier_head[i]);
 
@@ -910,7 +922,7 @@ static int __init opal_init(void)
 	}
 
 	/* Initialise OPAL messaging system */
-	opal_message_init();
+	opal_message_init(opal_node);
 
 	/* Initialise OPAL asynchronous completion interface */
 	opal_async_comp_init();
-- 
2.21.0

[PATCH v4 2/2] powerpc/powernv: Add new opal message type

[Vasant Hegde]

We have OPAL_MSG_PRD message type to pass prd related messages from OPAL
to `opal-prd`. It can handle messages upto 64 bytes. We have a requirement
to send bigger than 64 bytes of data from OPAL to `opal-prd`. Lets add new
message type (OPAL_MSG_PRD2) to pass bigger data.

Cc: Jeremy Kerr <jk@ozlabs.org>
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/opal-api.h       | 1 +
 arch/powerpc/platforms/powernv/opal-prd.c | 9 ++++++++-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/opal-api.h b/arch/powerpc/include/asm/opal-api.h
index 383242eb0dea..1cad413e1e0e 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -453,6 +453,7 @@ enum opal_msg_type {
 	OPAL_MSG_DPO		= 5,
 	OPAL_MSG_PRD		= 6,
 	OPAL_MSG_OCC		= 7,
+	OPAL_MSG_PRD2		= 8,
 	OPAL_MSG_TYPE_MAX,
 };
 
diff --git a/arch/powerpc/platforms/powernv/opal-prd.c b/arch/powerpc/platforms/powernv/opal-prd.c
index e072bf157d62..50a735d77192 100644
--- a/arch/powerpc/platforms/powernv/opal-prd.c
+++ b/arch/powerpc/platforms/powernv/opal-prd.c
@@ -342,7 +342,7 @@ static int opal_prd_msg_notifier(struct notifier_block *nb,
 	int msg_size, item_size;
 	unsigned long flags;
 
-	if (msg_type != OPAL_MSG_PRD)
+	if (msg_type != OPAL_MSG_PRD && msg_type != OPAL_MSG_PRD2)
 		return 0;
 
 	/* Calculate total size of the message and item we need to store. The
@@ -393,6 +393,13 @@ static int opal_prd_probe(struct platform_device *pdev)
 		return rc;
 	}
 
+	rc = opal_message_notifier_register(OPAL_MSG_PRD2, &opal_prd_event_nb);
+	if (rc) {
+		pr_err("%s: Couldn't register event notifier (%d)\n",
+		       __func__, OPAL_MSG_PRD2);
+		return rc;
+	}
+
 	rc = misc_register(&opal_prd_dev);
 	if (rc) {
 		pr_err("failed to register miscdev\n");
-- 
2.21.0

Re: [PATCH v4 1/2] powerpc/powernv: Enhance opal message read interface

[Michael Ellerman]

On Mon, 2019-08-26 at 06:57:00 UTC, Vasant Hegde wrote:
> Use "opal-msg-size" device tree property to allocate memory for "opal_msg".
> 
> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
> Cc: Jeremy Kerr <jk@ozlabs.org>
> Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/2be1d5d147955e6aea273dc73a9f0ae4510fd225

cheers