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Commit 1f91bca8 authored by K. Y. Srinivasan's avatar K. Y. Srinivasan Committed by Greg Kroah-Hartman
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Staging: hv: Introduce a function to map channel properties onto block device info 



In preparation for removing the IDE details from the block driver, implement
a function that maps channel properties to block device information.

Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarHaiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: default avatarHank Janssen <hjanssen@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 487ae7cd

drivers/staging/hv/storvsc.c

+68 −0
Original line number Diff line number Diff line
@@ -17,6 +17,8 @@ 
 * Authors:

 *   Haiyang Zhang <haiyangz@microsoft.com>

 *   Hank Janssen  <hjanssen@microsoft.com>

 *

 * 4/3/2011: K. Y. Srinivasan - Significant restructuring and cleanup.

 */

#include <linux/kernel.h>

#include <linux/sched.h>
@@ -592,6 +594,72 @@ int stor_vsc_on_io_request(struct hv_device *device, 
	return ret;

}



/*

 * The channel properties uniquely specify how the device is to be

 * presented to the guest. Map this information for use by the block

 * driver. For Linux guests on Hyper-V, we emulate a scsi HBA in the guest

 * (storvsc_drv) and so scsi devices in the guest  are handled by

 * native upper level Linux drivers. Consequently, Hyper-V

 * block driver, while being a generic block driver, presently does not

 * deal with anything other than devices that would need to be presented

 * to the guest as an IDE disk.

 *

 * This function maps the channel properties as embedded in the input

 * parameter device_info onto information necessary to register the

 * corresponding block device.

 *

 * Currently, there is no way to stop the emulation of the block device

 * on the host side. And so, to prevent the native IDE drivers in Linux

 * from taking over these devices (to be managedby Hyper-V block

 * driver), we will take over if need be the major of the IDE controllers.

 *

 */



int stor_vsc_get_major_info(struct storvsc_device_info *device_info,

			    struct storvsc_major_info *major_info)

{

	static bool ide0_registered;

	static bool ide1_registered;



	/*

	 * For now we only support IDE disks.

	 */

	major_info->devname = "ide";

	major_info->diskname = "hd";



	if (device_info->path_id) {

		major_info->major = 22;

		if (!ide1_registered)

			major_info->do_register = true;

		else {

			major_info->do_register = false;

			ide1_registered = true;

		}

		if (device_info->target_id)

			major_info->index = 3;

		 else

			major_info->index = 2;



		return 0;

	} else {

		major_info->major = 3;

		if (!ide0_registered)

			major_info->do_register = true;

		else {

			major_info->do_register = false;

			ide0_registered = true;

		}

		if (device_info->target_id)

			major_info->index = 1;

		else

			major_info->index = 0;



		return 0;

	}



	return -ENODEV;

}



/*

 * stor_vsc_on_cleanup - Perform any cleanup when the driver is removed

 */

drivers/staging/hv/storvsc_api.h

+10 −0
Original line number Diff line number Diff line
@@ -92,6 +92,14 @@ struct storvsc_device_info { 
	unsigned char target_id;

};



struct storvsc_major_info {

	int major;

	int index;

	bool do_register;

	char *devname;

	char *diskname;

};



/* A storvsc device is a device object that contains a vmbus channel */

struct storvsc_device {

	struct hv_device *device;
@@ -155,5 +163,7 @@ int stor_vsc_on_io_request(struct hv_device *device, 
				struct hv_storvsc_request *request);

void stor_vsc_on_cleanup(struct hv_driver *driver);



int stor_vsc_get_major_info(struct storvsc_device_info *device_info,

				struct storvsc_major_info *major_info);



#endif /* _STORVSC_API_H_ */