[RFC PATCH 1/2_v9] IPMI: Add one interface to get more info of low-level IPMI device

[yakui.zhao@intel.com]

From: Zhao Yakui <yakui.zhao@intel.com>

The IPMI smi_watcher will be used to catch the IPMI interface as they come or go.
In order to communicate with the correct IPMI device, it should be confirmed
 whether it is what we wanted especially on the system with multiple IPMI
devices. But the new_smi callback function of smi_watcher provides very
limited info(only the interface number and dev pointer) and there is no
detailed info about the low level interface. For example: which mechanism
registers the IPMI interface(ACPI, PCI, DMI and so on).

This is to add one interface that can get more info of low-level IPMI
device. For example: the ACPI device handle will be returned for the pnp_acpi
IPMI device.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
---
In this patch only the info of pnp_acpi IPMI is provided. If the detailed info
is also required for other mechanism, we can redesign the structure of
ipmi_smi_data and fill it correctly.

 drivers/char/ipmi/ipmi_msghandler.c |   26 ++++++++++++++++++++++++++
 drivers/char/ipmi/ipmi_si_intf.c    |   24 ++++++++++++++++++++----
 include/linux/ipmi.h                |   16 ++++++++++++++++
 include/linux/ipmi_smi.h            |   11 +++++++++++
 4 files changed, 73 insertions(+), 4 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index 4f3f8c9..f82d426 100644
--- a/drivers/char/ipmi/ipmi_msghandler.c
+++ b/drivers/char/ipmi/ipmi_msghandler.c
@@ -970,6 +970,32 @@ out_kfree:
 }
 EXPORT_SYMBOL(ipmi_create_user);
 
+int ipmi_get_smi_info(int if_num, enum ipmi_addr_src type,
+			union ipmi_smi_data *data)
+{
+	int           rv = 0;
+	ipmi_smi_t    intf;
+	struct ipmi_smi_handlers *handlers;
+
+	mutex_lock(&ipmi_interfaces_mutex);
+	list_for_each_entry_rcu(intf, &ipmi_interfaces, link) {
+		if (intf->intf_num == if_num)
+			goto found;
+	}
+	/* Not found, return an error */
+	rv = -EINVAL;
+	mutex_unlock(&ipmi_interfaces_mutex);
+	return rv;
+
+found:
+	handlers = intf->handlers;
+	rv = handlers->get_smi_info(intf->send_info, type, data);
+	mutex_unlock(&ipmi_interfaces_mutex);
+
+	return rv;
+}
+EXPORT_SYMBOL(ipmi_get_smi_info);
+
 static void free_user(struct kref *ref)
 {
 	ipmi_user_t user = container_of(ref, struct ipmi_user, refcount);
diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 3822b4f..ebb87b4 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -57,6 +57,7 @@
 #include <asm/irq.h>
 #include <linux/interrupt.h>
 #include <linux/rcupdate.h>
+#include <linux/ipmi.h>
 #include <linux/ipmi_smi.h>
 #include <asm/io.h>
 #include "ipmi_si_sm.h"
@@ -107,10 +108,6 @@ enum si_type {
 };
 static char *si_to_str[] = { "kcs", "smic", "bt" };
 
-enum ipmi_addr_src {
-	SI_INVALID = 0, SI_HOTMOD, SI_HARDCODED, SI_SPMI, SI_ACPI, SI_SMBIOS,
-	SI_PCI,	SI_DEVICETREE, SI_DEFAULT
-};
 static char *ipmi_addr_src_to_str[] = { NULL, "hotmod", "hardcoded", "SPMI",
 					"ACPI", "SMBIOS", "PCI",
 					"device-tree", "default" };
@@ -291,6 +288,7 @@ struct smi_info {
 	struct task_struct *thread;
 
 	struct list_head link;
+	union ipmi_smi_data smi_data;
 };
 
 #define smi_inc_stat(smi, stat) \
@@ -1183,6 +1181,21 @@ static int smi_start_processing(void       *send_info,
 	return 0;
 }
 
+static int get_smi_info(void *send_info,
+			enum ipmi_addr_src type,
+			union ipmi_smi_data *data)
+{
+	struct smi_info *new_smi = send_info;
+	union ipmi_smi_data *smi_data = &new_smi->smi_data;
+
+	if (new_smi->addr_source != type)
+		return -EINVAL;
+
+	memcpy(data, smi_data, sizeof(*smi_data));
+
+	return 0;
+}
+
 static void set_maintenance_mode(void *send_info, int enable)
 {
 	struct smi_info   *smi_info = send_info;
@@ -1194,6 +1207,7 @@ static void set_maintenance_mode(void *send_info, int enable)
 static struct ipmi_smi_handlers handlers = {
 	.owner                  = THIS_MODULE,
 	.start_processing       = smi_start_processing,
+	.get_smi_info		= get_smi_info,
 	.sender			= sender,
 	.request_events		= request_events,
 	.set_maintenance_mode   = set_maintenance_mode,
@@ -2140,6 +2154,8 @@ static int __devinit ipmi_pnp_probe(struct pnp_dev *dev,
 		return -ENOMEM;
 
 	info->addr_source = SI_ACPI;
+	info->smi_data.acpi_data.acpi_handle = acpi_dev->handle;
+	info->smi_data.acpi_data.dev = &dev->dev;
 	printk(KERN_INFO PFX "probing via ACPI\n");
 
 	handle = acpi_dev->handle;
diff --git a/include/linux/ipmi.h b/include/linux/ipmi.h
index 65aae34..04e4a90 100644
--- a/include/linux/ipmi.h
+++ b/include/linux/ipmi.h
@@ -454,6 +454,22 @@ unsigned int ipmi_addr_length(int addr_type);
 /* Validate that the given IPMI address is valid. */
 int ipmi_validate_addr(struct ipmi_addr *addr, int len);
 
+enum ipmi_addr_src {
+	SI_INVALID = 0, SI_HOTMOD, SI_HARDCODED, SI_SPMI, SI_ACPI, SI_SMBIOS,
+	SI_PCI,	SI_DEVICETREE, SI_DEFAULT
+};
+union ipmi_smi_data{
+	/* If the other type of data is required, please add it	 */
+	u8 data[16];
+	struct {
+		void *acpi_handle;
+		struct device *dev;
+	} acpi_data;
+};
+
+/* This is to get the private info of ipmi_smi_t */
+extern int ipmi_get_smi_info(int if_num, enum ipmi_addr_src type,
+		union ipmi_smi_data *data);
 #endif /* __KERNEL__ */
 
 
diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h
index 4b48318..d5bae83 100644
--- a/include/linux/ipmi_smi.h
+++ b/include/linux/ipmi_smi.h
@@ -86,6 +86,17 @@ struct ipmi_smi_handlers {
 	int (*start_processing)(void       *send_info,
 				ipmi_smi_t new_intf);
 
+	/*
+	 * Get the detailed private info of the low level interface and store
+	 * it into the union structure of ipmi_smi_data. For example: the
+	 * ACPI device handle will be returned for the pnp_acpi IPMI device.
+	 * Of course it will firstly compare the interface type of low-level
+	 * interface(Hardcoded type, DMI, ACPI and so on). If the type doesn't
+	 * match, it will return -EINVAL.
+	 */
+	int (*get_smi_info)(void *send_info, enum ipmi_addr_src type,
+				union ipmi_smi_data *data);
+
 	/* Called to enqueue an SMI message to be sent.  This
 	   operation is not allowed to fail.  If an error occurs, it
 	   should report back the error in a received message.  It may
-- 
1.5.4.5