[PATCH v7 10/16] lpfc: vmid: Functions to manage vmids

Muneendra
2021-01-07T04:55:42Z

This patch contains the 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.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Gaurav Srivastava <gaurav.srivastava@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>

---
v7:
No change

v6:
Added Forward declarations and functions to static

v5:
Changed Return code to non-numeric/Symbol

v4:
No change

v3:
No change

v2:
Ported the patch on top of 5.10/scsi-queue
---
drivers/scsi/lpfc/lpfc_scsi.c | 148 ++++++++++++++++++++++++++++++++++
1 file changed, 148 insertions(+)

diff --git a/drivers/scsi/lpfc/lpfc_scsi.c b/drivers/scsi/lpfc/lpfc_scsi.c
index b79b6f03cdb6..53baee21e0f9 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.c
+++ b/drivers/scsi/lpfc/lpfc_scsi.c
@@ -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 int
+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)
@@ -5131,6 +5140,145 @@ void lpfc_poll_timeout(struct timer_list *t)
}
}

+/*
+ * lpfc_get_vmid_from_hastable - 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
+ * Returns 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_hastable(struct lpfc_vport *vport,
+ u32 hash, u8 *buf)
+{
+ struct lpfc_vmid *vmp;
+ u16 count = 0;
+
+ while (count < LPFC_VMID_HASH_SIZE) {
+ vmp = vport->hash_table[hash];
+ if (vmp) {
+ if (strncmp(&vmp->host_vmid[0], buf, 16) == 0)
+ return vmp;
+ } else {
+ return NULL;
+ }
+ /* search the next available slot and continue till entry */
+ /* is found */
+ count++;
+ hash++;
+
+ /* or the end is reached */
+ if (hash == LPFC_VMID_HASH_SIZE)
+ hash = 0;
+ }
+ return NULL;
+}
+
+/*
+ * lpfc_put_vmid_from_hastable - 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 IO
+ *
+ * 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 int
+lpfc_put_vmid_in_hashtable(struct lpfc_vport *vport, u32 hash,
+ struct lpfc_vmid *vmp)
+{
+ int count = 0;
+
+ while (count < LPFC_VMID_HASH_SIZE) {
+ if (!vport->hash_table[hash]) {
+ vport->hash_table[hash] = vmp;
+ vmp->hash_index = hash;
+ return FAILURE;
+ }
+ /* if the slot is already occupied, a collision has occurred. */
+ /* Store in the next available slot */
+ count++;
+ hash++;
+ /* table is full */
+ if (hash == LPFC_VMID_HASH_SIZE)
+ hash = 0;
+ }
+ return 0;
+}
+
+/*
+ * lpfc_vmid_hash_fn- creates a hash value of the UUID
+ * @uuid: uuid associated with the VE
+ * @len: length of the UUID
+ * Returns the calculated hash value
+ */
+int lpfc_vmid_hash_fn(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 cmmd descriptor
+ * @vmp: Pointer to a VMID entry representing a VM sending IO
+ * @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_hastable(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.