[RFC PATCH 1/4] 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 mechansim
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, please add them in the structure of
ipmi_smi_info.

 drivers/char/ipmi/ipmi_msghandler.c |   26 ++++++++++++++++++++++++++
 drivers/char/ipmi/ipmi_si_intf.c    |   28 ++++++++++++++++++++++++----
 include/linux/ipmi.h                |   23 +++++++++++++++++++++++
 include/linux/ipmi_smi.h            |   11 +++++++++++
 4 files changed, 84 insertions(+), 4 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c
index 4f3f8c9..6f4da59 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,
+			struct ipmi_smi_info **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 7bd7c45..73b1c82 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;
+	struct ipmi_smi_info smi_data;
 };
 
 #define smi_inc_stat(smi, stat) \
@@ -1186,6 +1184,22 @@ static int smi_start_processing(void       *send_info,
 	return 0;
 }
 
+static int get_smi_info(void *send_info,
+			enum ipmi_addr_src type,
+			struct ipmi_smi_info **data)
+{
+	struct smi_info *new_smi = send_info;
+	struct ipmi_smi_info *smi_data = &new_smi->smi_data;
+
+	if (new_smi->addr_source != type)
+		return -EINVAL;
+
+	smi_data->addr_src = type;
+
+	*data = smi_data;
+	return 0;
+}
+
 static void set_maintenance_mode(void *send_info, int enable)
 {
 	struct smi_info   *smi_info = send_info;
@@ -1197,6 +1211,7 @@ 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,
@@ -2143,6 +2158,8 @@ static int __devinit ipmi_pnp_probe(struct pnp_dev *dev,
 		return -ENOMEM;
 
 	info->addr_source = SI_ACPI;
+	info->smi_data.smi_info.acpi_info.acpi_handle =
+				acpi_dev->handle;
 	printk(KERN_INFO PFX "probing via ACPI\n");
 
 	handle = acpi_dev->handle;
@@ -3092,6 +3109,7 @@ static int try_smi_init(struct smi_info *new_smi)
 {
 	int rv = 0;
 	int i;
+	struct ipmi_smi_info *smi_data = &new_smi->smi_data;
 
 	printk(KERN_INFO PFX "Trying %s-specified %s state"
 	       " machine at %s address 0x%lx, slave address 0x%x,"
@@ -3217,6 +3235,8 @@ static int try_smi_init(struct smi_info *new_smi)
 		new_smi->dev_registered = 1;
 	}
 
+	smi_data->dev = new_smi->dev;
+
 	rv = ipmi_register_smi(&handlers,
 			       new_smi,
 			       &new_smi->device_id,
diff --git a/include/linux/ipmi.h b/include/linux/ipmi.h
index 65aae34..1ce428f 100644
--- a/include/linux/ipmi.h
+++ b/include/linux/ipmi.h
@@ -454,6 +454,29 @@ 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
+};
+struct ipmi_smi_info{
+	enum ipmi_addr_src addr_src;
+	struct device *dev;
+	union {
+		/*
+		 * Now only SI_ACPI info is provided. If the info is required
+		 * for other type, please add it
+		 */
+#ifdef CONFIG_ACPI
+		struct {
+			void *acpi_handle;
+		} acpi_info;
+#endif
+	} smi_info;
+};
+
+/* This is to get the private info of ipmi_smi_t. The pointer is returned */
+extern int ipmi_get_smi_info(int if_num, enum ipmi_addr_src type,
+		struct ipmi_smi_info **data);
 #endif /* __KERNEL__ */
 
 
diff --git a/include/linux/ipmi_smi.h b/include/linux/ipmi_smi.h
index 4b48318..bfa8f40 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 return
+	 * the corresponding pointer.
+	 * 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,
+				struct ipmi_smi_info **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