Commit dc50715e authored by Gaurav Srivastava's avatar Gaurav Srivastava Committed by Martin K. Petersen
Browse files

scsi: lpfc: vmid: Functions to manage VMIDs 

Implement routines to save, retrieve, and remove the VMIDs from the data
structure. A hash table is used to save the VMIDs and the corresponding
UUIDs associated with the application/VMs.

Link: https://lore.kernel.org/r/20210608043556.274139-9-muneendra.kumar@broadcom.com


Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Signed-off-by: default avatarGaurav Srivastava <gaurav.srivastava@broadcom.com>
Signed-off-by: default avatarJames Smart <jsmart2021@gmail.com>
Signed-off-by: default avatarMuneendra Kumar <muneendra.kumar@broadcom.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 7e473de7

drivers/scsi/lpfc/lpfc_scsi.c

+118 −0
Original line number Diff line number Diff line
@@ -28,6 +28,7 @@ 
#include <asm/unaligned.h>

#include <linux/t10-pi.h>

#include <linux/crc-t10dif.h>

#include <linux/blk-cgroup.h>

#include <net/checksum.h>



#include <scsi/scsi.h>
@@ -86,6 +87,14 @@ static void 
lpfc_release_scsi_buf_s3(struct lpfc_hba *phba, struct lpfc_io_buf *psb);

static int

lpfc_prot_group_type(struct lpfc_hba *phba, struct scsi_cmnd *sc);

static void

lpfc_put_vmid_in_hashtable(struct lpfc_vport *vport, u32 hash,

			   struct lpfc_vmid *vmp);

static void lpfc_vmid_update_entry(struct lpfc_vport *vport, struct scsi_cmnd

				   *cmd, struct lpfc_vmid *vmp,

				   union lpfc_vmid_io_tag *tag);

static void lpfc_vmid_assign_cs_ctl(struct lpfc_vport *vport,

				    struct lpfc_vmid *vmid);



static inline unsigned

lpfc_cmd_blksize(struct scsi_cmnd *sc)
@@ -5160,6 +5169,115 @@ void lpfc_poll_timeout(struct timer_list *t) 
	}

}



/*

 * lpfc_get_vmid_from_hashtable - search the UUID in the hash table

 * @vport: The virtual port for which this call is being executed.

 * @hash: calculated hash value

 * @buf: uuid associated with the VE

 * Return the VMID entry associated with the UUID

 * Make sure to acquire the appropriate lock before invoking this routine.

 */

struct lpfc_vmid *lpfc_get_vmid_from_hashtable(struct lpfc_vport *vport,

					      u32 hash, u8 *buf)

{

	struct lpfc_vmid *vmp;



	hash_for_each_possible(vport->hash_table, vmp, hnode, hash) {

		if (memcmp(&vmp->host_vmid[0], buf, 16) == 0)

			return vmp;

	}

	return NULL;

}



/*

 * lpfc_put_vmid_in_hashtable - put the VMID in the hash table

 * @vport: The virtual port for which this call is being executed.

 * @hash - calculated hash value

 * @vmp: Pointer to a VMID entry representing a VM sending I/O

 *

 * This routine will insert the newly acquired VMID entity in the hash table.

 * Make sure to acquire the appropriate lock before invoking this routine.

 */

static void

lpfc_put_vmid_in_hashtable(struct lpfc_vport *vport, u32 hash,

			   struct lpfc_vmid *vmp)

{

	hash_add(vport->hash_table, &vmp->hnode, hash);

}



/*

 * lpfc_vmid_hash_fn - create a hash value of the UUID

 * @vmid: uuid associated with the VE

 * @len: length of the VMID string

 * Returns the calculated hash value

 */

int lpfc_vmid_hash_fn(const char *vmid, int len)

{

	int c;

	int hash = 0;



	if (len == 0)

		return 0;

	while (len--) {

		c = *vmid++;

		if (c >= 'A' && c <= 'Z')

			c += 'a' - 'A';



		hash = (hash + (c << LPFC_VMID_HASH_SHIFT) +

			(c >> LPFC_VMID_HASH_SHIFT)) * 19;

	}



	return hash & LPFC_VMID_HASH_MASK;

}



/*

 * lpfc_vmid_update_entry - update the vmid entry in the hash table

 * @vport: The virtual port for which this call is being executed.

 * @cmd: address of scsi cmd descriptor

 * @vmp: Pointer to a VMID entry representing a VM sending I/O

 * @tag: VMID tag

 */

static void lpfc_vmid_update_entry(struct lpfc_vport *vport, struct scsi_cmnd

				   *cmd, struct lpfc_vmid *vmp,

				   union lpfc_vmid_io_tag *tag)

{

	u64 *lta;



	if (vport->vmid_priority_tagging)

		tag->cs_ctl_vmid = vmp->un.cs_ctl_vmid;

	else

		tag->app_id = vmp->un.app_id;



	if (cmd->sc_data_direction == DMA_TO_DEVICE)

		vmp->io_wr_cnt++;

	else

		vmp->io_rd_cnt++;



	/* update the last access timestamp in the table */

	lta = per_cpu_ptr(vmp->last_io_time, raw_smp_processor_id());

	*lta = jiffies;

}



static void lpfc_vmid_assign_cs_ctl(struct lpfc_vport *vport,

				    struct lpfc_vmid *vmid)

{

	u32 hash;

	struct lpfc_vmid *pvmid;



	if (vport->port_type == LPFC_PHYSICAL_PORT) {

		vmid->un.cs_ctl_vmid = lpfc_vmid_get_cs_ctl(vport);

	} else {

		hash = lpfc_vmid_hash_fn(vmid->host_vmid, vmid->vmid_len);

		pvmid =

		    lpfc_get_vmid_from_hashtable(vport->phba->pport, hash,

						vmid->host_vmid);

		if (pvmid)

			vmid->un.cs_ctl_vmid = pvmid->un.cs_ctl_vmid;

		else

			vmid->un.cs_ctl_vmid = lpfc_vmid_get_cs_ctl(vport);

	}

}



/**

 * lpfc_queuecommand - scsi_host_template queuecommand entry point

 * @shost: kernel scsi host pointer.