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

[ykzhao <yakui.zhao@intel.com>]

On Wed, 2010-09-15 at 16:06 +0800, Zhao, Yakui wrote:
> 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.

Hi, Corey
	
	Any comment about this patch? Does the interface make sense?

Thanks.
> 
> 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