From: "Matthew R. Ochs" <mro...@linux.vnet.ibm.com>
At present, the cxlflash driver only supports hardware with two FC
ports. The code was initially designed with this assumption and is
dependent on having two FC ports - adding more ports will break logic
within the driver.
To mitigate this issue, remove the existing port assumptions and
transition the code to support more than two ports. As a side effect,
clarify the interpretation of the DK_CXLFLASH_ALL_PORTS_ACTIVE flag.
Signed-off-by: Matthew R. Ochs <mro...@linux.vnet.ibm.com>
Signed-off-by: Uma Krishnan <ukri...@linux.vnet.ibm.com>
---
Documentation/powerpc/cxlflash.txt | 5 +++
drivers/scsi/cxlflash/common.h | 4 ++
drivers/scsi/cxlflash/lunmgt.c | 4 +-
drivers/scsi/cxlflash/main.c | 13 +++---
drivers/scsi/cxlflash/sislite.h | 2 +-
drivers/scsi/cxlflash/superpipe.c | 2 +-
drivers/scsi/cxlflash/superpipe.h | 3 --
drivers/scsi/cxlflash/vlun.c | 89 +++++++++++++++++++++++++-------------
8 files changed, 77 insertions(+), 45 deletions(-)
diff --git a/Documentation/powerpc/cxlflash.txt
b/Documentation/powerpc/cxlflash.txt
index 6d9a2ed..66b4496 100644
--- a/Documentation/powerpc/cxlflash.txt
+++ b/Documentation/powerpc/cxlflash.txt
@@ -239,6 +239,11 @@ DK_CXLFLASH_USER_VIRTUAL
resource handle that is provided is already referencing provisioned
storage. This is reflected by the last LBA being a non-zero value.
+ When a LUN is accessible from more than one port, this ioctl will
+ return with the DK_CXLFLASH_ALL_PORTS_ACTIVE return flag set. This
+ provides the user with a hint that I/O can be retried in the event
+ of an I/O error as the LUN can be reached over multiple paths.
+
DK_CXLFLASH_VLUN_RESIZE
-----------------------
This ioctl is responsible for resizing a previously created virtual
diff --git a/drivers/scsi/cxlflash/common.h b/drivers/scsi/cxlflash/common.h
index 6a04867..ee23e81 100644
--- a/drivers/scsi/cxlflash/common.h
+++ b/drivers/scsi/cxlflash/common.h
@@ -29,6 +29,10 @@ extern const struct file_operations cxlflash_cxl_fops;
#define NUM_FC_PORTS CXLFLASH_NUM_FC_PORTS /* ports per AFU */
#define MAX_FC_PORTS CXLFLASH_MAX_FC_PORTS /* ports per AFU */
+#define CHAN2PORTMASK(_x) (1 << (_x)) /* channel to port mask */
+#define PORTMASK2CHAN(_x) (ilog2((_x))) /* port mask to channel */
+#define PORTNUM2CHAN(_x) ((_x) - 1) /* port number to channel */
+
#define CXLFLASH_BLOCK_SIZE 4096 /* 4K blocks */
#define CXLFLASH_MAX_XFER_SIZE 16777216 /* 16MB transfer */
#define CXLFLASH_MAX_SECTORS (CXLFLASH_MAX_XFER_SIZE/512) /* SCSI wants
diff --git a/drivers/scsi/cxlflash/lunmgt.c b/drivers/scsi/cxlflash/lunmgt.c
index 0efed17..4d232e2 100644
--- a/drivers/scsi/cxlflash/lunmgt.c
+++ b/drivers/scsi/cxlflash/lunmgt.c
@@ -252,7 +252,7 @@ int cxlflash_manage_lun(struct scsi_device *sdev,
* in unpacked, AFU-friendly format, and hang LUN reference in
* the sdev.
*/
- lli->port_sel |= CHAN2PORT(chan);
+ lli->port_sel |= CHAN2PORTMASK(chan);
lli->lun_id[chan] = lun_to_lunid(sdev->lun);
sdev->hostdata = lli;
} else if (flags & DK_CXLFLASH_MANAGE_LUN_DISABLE_SUPERPIPE) {
@@ -264,7 +264,7 @@ int cxlflash_manage_lun(struct scsi_device *sdev,
* tracking when no more references exist.
*/
sdev->hostdata = NULL;
- lli->port_sel &= ~CHAN2PORT(chan);
+ lli->port_sel &= ~CHAN2PORTMASK(chan);
if (lli->port_sel == 0U)
lli->in_table = false;
}
diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index 3f9c869..04e1a8e 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -365,7 +365,6 @@ static int wait_resp(struct afu *afu, struct afu_cmd *cmd)
*/
static int send_tmf(struct afu *afu, struct scsi_cmnd *scp, u64 tmfcmd)
{
- u32 port_sel = scp->device->channel + 1;
struct cxlflash_cfg *cfg = shost_priv(scp->device->host);
struct afu_cmd *cmd = sc_to_afucz(scp);
struct device *dev = &cfg->dev->dev;
@@ -388,7 +387,7 @@ static int send_tmf(struct afu *afu, struct scsi_cmnd *scp,
u64 tmfcmd)
cmd->rcb.ctx_id = afu->ctx_hndl;
cmd->rcb.msi = SISL_MSI_RRQ_UPDATED;
- cmd->rcb.port_sel = port_sel;
+ cmd->rcb.port_sel = CHAN2PORTMASK(scp->device->channel);
cmd->rcb.lun_id = lun_to_lunid(scp->device->lun);
cmd->rcb.req_flags = (SISL_REQ_FLAGS_PORT_LUN_ID |
SISL_REQ_FLAGS_SUP_UNDERRUN |
@@ -444,7 +443,6 @@ static int cxlflash_queuecommand(struct Scsi_Host *host,
struct scsi_cmnd *scp)
struct device *dev = &cfg->dev->dev;
struct afu_cmd *cmd = sc_to_afucz(scp);
struct scatterlist *sg = scsi_sglist(scp);
- u32 port_sel = scp->device->channel + 1;
u16 req_flags = SISL_REQ_FLAGS_SUP_UNDERRUN;
ulong lock_flags;
int nseg = 0;
@@ -503,7 +501,7 @@ static int cxlflash_queuecommand(struct Scsi_Host *host,
struct scsi_cmnd *scp)
cmd->rcb.ctx_id = afu->ctx_hndl;
cmd->rcb.msi = SISL_MSI_RRQ_UPDATED;
- cmd->rcb.port_sel = port_sel;
+ cmd->rcb.port_sel = CHAN2PORTMASK(scp->device->channel);
cmd->rcb.lun_id = lun_to_lunid(scp->device->lun);
if (scp->sc_data_direction == DMA_TO_DEVICE)
@@ -1558,7 +1556,8 @@ static int init_global(struct cxlflash_cfg *cfg)
writeq_be(PORT0, &afu->afu_map->global.regs.afu_port_sel);
num_ports = 0;
} else {
- writeq_be(BOTH_PORTS, &afu->afu_map->global.regs.afu_port_sel);
+ writeq_be(PORT_MASK(cfg->num_fc_ports),
+ &afu->afu_map->global.regs.afu_port_sel);
num_ports = cfg->num_fc_ports;
}
@@ -2190,7 +2189,7 @@ static ssize_t lun_mode_store(struct device *dev,
if (afu->internal_lun)
shost->max_channel = 0;
else
- shost->max_channel = cfg->num_fc_ports - 1;
+ shost->max_channel = PORTNUM2CHAN(cfg->num_fc_ports);
afu_reset(cfg);
scsi_scan_host(cfg->host);
@@ -2529,7 +2528,7 @@ static int cxlflash_probe(struct pci_dev *pdev,
host->max_id = CXLFLASH_MAX_NUM_TARGETS_PER_BUS;
host->max_lun = CXLFLASH_MAX_NUM_LUNS_PER_TARGET;
- host->max_channel = NUM_FC_PORTS - 1;
+ host->max_channel = PORTNUM2CHAN(NUM_FC_PORTS);
host->unique_id = host->host_no;
host->max_cmd_len = CXLFLASH_MAX_CDB_LEN;
diff --git a/drivers/scsi/cxlflash/sislite.h b/drivers/scsi/cxlflash/sislite.h
index 0db4bc1..f26f41b 100644
--- a/drivers/scsi/cxlflash/sislite.h
+++ b/drivers/scsi/cxlflash/sislite.h
@@ -479,7 +479,7 @@ struct sisl_rht_entry_f1 {
#define PORT0 0x01U
#define PORT1 0x02U
-#define BOTH_PORTS (PORT0 | PORT1)
+#define PORT_MASK(_n) ((1 << (_n)) - 1)
/* AFU Sync Mode byte */
#define AFU_LW_SYNC 0x0U
diff --git a/drivers/scsi/cxlflash/superpipe.c
b/drivers/scsi/cxlflash/superpipe.c
index 90869ce..488330f 100644
--- a/drivers/scsi/cxlflash/superpipe.c
+++ b/drivers/scsi/cxlflash/superpipe.c
@@ -1935,7 +1935,7 @@ static int cxlflash_disk_direct_open(struct scsi_device
*sdev, void *arg)
u64 lun_size = 0;
u64 last_lba = 0;
u64 rsrc_handle = -1;
- u32 port = CHAN2PORT(sdev->channel);
+ u32 port = CHAN2PORTMASK(sdev->channel);
int rc = 0;
diff --git a/drivers/scsi/cxlflash/superpipe.h
b/drivers/scsi/cxlflash/superpipe.h
index 690ce9c..8269ff8 100644
--- a/drivers/scsi/cxlflash/superpipe.h
+++ b/drivers/scsi/cxlflash/superpipe.h
@@ -33,9 +33,6 @@ extern struct cxlflash_global global;
#define MAX_SECTOR_UNIT 512 /* max_sector is in 512 byte multiples */
-#define CHAN2PORT(_x) ((_x) + 1)
-#define PORT2CHAN(_x) ((_x) - 1)
-
enum lun_mode {
MODE_NONE = 0,
MODE_VIRTUAL,
diff --git a/drivers/scsi/cxlflash/vlun.c b/drivers/scsi/cxlflash/vlun.c
index 8fcc804..547c8ff 100644
--- a/drivers/scsi/cxlflash/vlun.c
+++ b/drivers/scsi/cxlflash/vlun.c
@@ -819,8 +819,8 @@ int cxlflash_vlun_resize(struct scsi_device *sdev,
void cxlflash_restore_luntable(struct cxlflash_cfg *cfg)
{
struct llun_info *lli, *temp;
- u32 chan;
u32 lind;
+ int k;
struct afu *afu = cfg->afu;
struct device *dev = &cfg->dev->dev;
struct sisl_global_map __iomem *agm = &afu->afu_map->global;
@@ -832,33 +832,41 @@ void cxlflash_restore_luntable(struct cxlflash_cfg *cfg)
continue;
lind = lli->lun_index;
+ dev_dbg(dev, "%s: Virtual LUNs on slot %d:\n", __func__, lind);
- if (lli->port_sel == BOTH_PORTS) {
- writeq_be(lli->lun_id[0], &agm->fc_port[0][lind]);
- writeq_be(lli->lun_id[1], &agm->fc_port[1][lind]);
- dev_dbg(dev, "%s: Virtual LUN on slot %d id0=%llx "
- "id1=%llx\n", __func__, lind,
- lli->lun_id[0], lli->lun_id[1]);
- } else {
- chan = PORT2CHAN(lli->port_sel);
- writeq_be(lli->lun_id[chan], &agm->fc_port[chan][lind]);
- dev_dbg(dev, "%s: Virtual LUN on slot %d chan=%d "
- "id=%llx\n", __func__, lind, chan,
- lli->lun_id[chan]);
- }
+ for (k = 0; k < cfg->num_fc_ports; k++)
+ if (lli->port_sel & (1 << k)) {
+ writeq_be(lli->lun_id[k],
+ &agm->fc_port[k][lind]);
+ dev_dbg(dev, "\t%d=%llx\n", k, lli->lun_id[k]);
+ }
}
mutex_unlock(&global.mutex);
}
/**
+ * get_num_ports() - compute number of ports from port selection mask
+ * @psm: Port selection mask.
+ *
+ * Return: Population count of port selection mask
+ */
+static inline u8 get_num_ports(u32 psm)
+{
+ static const u8 bits[16] = { 0, 1, 1, 2, 1, 2, 2, 3,
+ 1, 2, 2, 3, 2, 3, 3, 4 };
+
+ return bits[psm & 0xf];
+}
+
+/**
* init_luntable() - write an entry in the LUN table
* @cfg: Internal structure associated with the host.
* @lli: Per adapter LUN information structure.
*
- * On successful return, a LUN table entry is created.
- * At the top for LUNs visible on both ports.
- * At the bottom for LUNs visible only on one port.
+ * On successful return, a LUN table entry is created:
+ * - at the top for LUNs visible on multiple ports.
+ * - at the bottom for LUNs visible only on one port.
*
* Return: 0 on success, -errno on failure
*/
@@ -866,7 +874,9 @@ static int init_luntable(struct cxlflash_cfg *cfg, struct
llun_info *lli)
{
u32 chan;
u32 lind;
+ u32 nports;
int rc = 0;
+ int k;
struct afu *afu = cfg->afu;
struct device *dev = &cfg->dev->dev;
struct sisl_global_map __iomem *agm = &afu->afu_map->global;
@@ -876,29 +886,46 @@ static int init_luntable(struct cxlflash_cfg *cfg, struct
llun_info *lli)
if (lli->in_table)
goto out;
- if (lli->port_sel == BOTH_PORTS) {
+ nports = get_num_ports(lli->port_sel);
+ if (nports == 0 || nports > cfg->num_fc_ports) {
+ WARN(1, "Unsupported port configuration nports=%u", nports);
+ rc = -EIO;
+ goto out;
+ }
+
+ if (nports > 1) {
/*
- * If this LUN is visible from both ports, we will put
+ * When LUN is visible from multiple ports, we will put
* it in the top half of the LUN table.
*/
- if ((cfg->promote_lun_index == cfg->last_lun_index[0]) ||
- (cfg->promote_lun_index == cfg->last_lun_index[1])) {
- rc = -ENOSPC;
- goto out;
+ for (k = 0; k < cfg->num_fc_ports; k++) {
+ if (!(lli->port_sel & (1 << k)))
+ continue;
+
+ if (cfg->promote_lun_index == cfg->last_lun_index[k]) {
+ rc = -ENOSPC;
+ goto out;
+ }
}
lind = lli->lun_index = cfg->promote_lun_index;
- writeq_be(lli->lun_id[0], &agm->fc_port[0][lind]);
- writeq_be(lli->lun_id[1], &agm->fc_port[1][lind]);
+ dev_dbg(dev, "%s: Virtual LUNs on slot %d:\n", __func__, lind);
+
+ for (k = 0; k < cfg->num_fc_ports; k++) {
+ if (!(lli->port_sel & (1 << k)))
+ continue;
+
+ writeq_be(lli->lun_id[k], &agm->fc_port[k][lind]);
+ dev_dbg(dev, "\t%d=%llx\n", k, lli->lun_id[k]);
+ }
+
cfg->promote_lun_index++;
- dev_dbg(dev, "%s: Virtual LUN on slot %d id0=%llx id1=%llx\n",
- __func__, lind, lli->lun_id[0], lli->lun_id[1]);
} else {
/*
- * If this LUN is visible only from one port, we will put
+ * When LUN is visible only from one port, we will put
* it in the bottom half of the LUN table.
*/
- chan = PORT2CHAN(lli->port_sel);
+ chan = PORTMASK2CHAN(lli->port_sel);
if (cfg->promote_lun_index == cfg->last_lun_index[chan]) {
rc = -ENOSPC;
goto out;
@@ -907,7 +934,7 @@ static int init_luntable(struct cxlflash_cfg *cfg, struct
llun_info *lli)
lind = lli->lun_index = cfg->last_lun_index[chan];
writeq_be(lli->lun_id[chan], &agm->fc_port[chan][lind]);
cfg->last_lun_index[chan]--;
- dev_dbg(dev, "%s: Virtual LUN on slot %d chan=%d id=%llx\n",
+ dev_dbg(dev, "%s: Virtual LUNs on slot %d:\n\t%d=%llx\n",
__func__, lind, chan, lli->lun_id[chan]);
}
@@ -1016,7 +1043,7 @@ int cxlflash_disk_virtual_open(struct scsi_device *sdev,
void *arg)
virt->last_lba = last_lba;
virt->rsrc_handle = rsrc_handle;
- if (lli->port_sel == BOTH_PORTS)
+ if (get_num_ports(lli->port_sel) > 1)
virt->hdr.return_flags |= DK_CXLFLASH_ALL_PORTS_ACTIVE;
out:
if (likely(ctxi))
--
2.1.0
