[PATCH 5.19 095/717] scsi: lpfc: Rework MIB Rx Monitor debug info logic

Greg Kroah-Hartman
2022-10-22T09:00:05Z

From: James Smart <jsmart2021@gmail.com>

commit bd269188ea94e40ab002cad7b0df8f12b8f0de54 upstream.

The kernel test robot reported the following sparse warning:

arch/arm64/include/asm/cmpxchg.h:88:1: sparse: sparse: cast truncates
bits from constant value (369 becomes 69)

On arm64, atomic_xchg only works on 8-bit byte fields. Thus, the macro
usage of LPFC_RXMONITOR_TABLE_IN_USE can be unintentionally truncated
leading to all logic involving the LPFC_RXMONITOR_TABLE_IN_USE macro to not
work properly.

Replace the Rx Table atomic_t indexing logic with a new
lpfc_rx_info_monitor structure that holds a circular ring buffer. For
locking semantics, a spinlock_t is used.

Link: https://lore.kernel.org/r/20220819011736.14141-4-jsmart2021@gmail.com
Fixes: 17b27ac59224 ("scsi: lpfc: Add rx monitoring statistics")
Cc: <stable@vger.kernel.org> # v5.15+
Co-developed-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/scsi/lpfc/lpfc.h | 14 +-
drivers/scsi/lpfc/lpfc_crtn.h | 8 +
drivers/scsi/lpfc/lpfc_debugfs.c | 59 ++----------
drivers/scsi/lpfc/lpfc_debugfs.h | 2
drivers/scsi/lpfc/lpfc_init.c | 83 ++++-------------
drivers/scsi/lpfc/lpfc_mem.c | 9 +
drivers/scsi/lpfc/lpfc_sli.c | 190 +++++++++++++++++++++++++++++++++++++--
7 files changed, 240 insertions(+), 125 deletions(-)

--- a/drivers/scsi/lpfc/lpfc.h
+++ b/drivers/scsi/lpfc/lpfc.h
@@ -1576,10 +1576,7 @@ struct lpfc_hba {
u32 cgn_acqe_cnt;

/* RX monitor handling for CMF */
- struct rxtable_entry *rxtable; /* RX_monitor information */
- atomic_t rxtable_idx_head;
-#define LPFC_RXMONITOR_TABLE_IN_USE (LPFC_MAX_RXMONITOR_ENTRY + 73)
- atomic_t rxtable_idx_tail;
+ struct lpfc_rx_info_monitor *rx_monitor;
atomic_t rx_max_read_cnt; /* Maximum read bytes */
uint64_t rx_block_cnt;

@@ -1628,7 +1625,7 @@ struct lpfc_hba {

#define LPFC_MAX_RXMONITOR_ENTRY 800
#define LPFC_MAX_RXMONITOR_DUMP 32
-struct rxtable_entry {
+struct rx_info_entry {
uint64_t cmf_bytes; /* Total no of read bytes for CMF_SYNC_WQE */
uint64_t total_bytes; /* Total no of read bytes requested */
uint64_t rcv_bytes; /* Total no of read bytes completed */
@@ -1643,6 +1640,13 @@ struct rxtable_entry {
uint32_t timer_interval;
};

+struct lpfc_rx_info_monitor {
+ struct rx_info_entry *ring; /* info organized in a circular buffer */
+ u32 head_idx, tail_idx; /* index to head/tail of ring */
+ spinlock_t lock; /* spinlock for ring */
+ u32 entries; /* storing number entries/size of ring */
+};
+
static inline struct Scsi_Host *
lpfc_shost_from_vport(struct lpfc_vport *vport)
{
--- a/drivers/scsi/lpfc/lpfc_crtn.h
+++ b/drivers/scsi/lpfc/lpfc_crtn.h
@@ -92,6 +92,14 @@ void lpfc_cgn_dump_rxmonitor(struct lpfc
void lpfc_cgn_update_stat(struct lpfc_hba *phba, uint32_t dtag);
void lpfc_unblock_requests(struct lpfc_hba *phba);
void lpfc_block_requests(struct lpfc_hba *phba);
+int lpfc_rx_monitor_create_ring(struct lpfc_rx_info_monitor *rx_monitor,
+ u32 entries);
+void lpfc_rx_monitor_destroy_ring(struct lpfc_rx_info_monitor *rx_monitor);
+void lpfc_rx_monitor_record(struct lpfc_rx_info_monitor *rx_monitor,
+ struct rx_info_entry *entry);
+u32 lpfc_rx_monitor_report(struct lpfc_hba *phba,
+ struct lpfc_rx_info_monitor *rx_monitor, char *buf,
+ u32 buf_len, u32 max_read_entries);

void lpfc_mbx_cmpl_local_config_link(struct lpfc_hba *, LPFC_MBOXQ_t *);
void lpfc_mbx_cmpl_reg_login(struct lpfc_hba *, LPFC_MBOXQ_t *);
--- a/drivers/scsi/lpfc/lpfc_debugfs.c
+++ b/drivers/scsi/lpfc/lpfc_debugfs.c
@@ -5531,7 +5531,7 @@ lpfc_rx_monitor_open(struct inode *inode
if (!debug)
goto out;

- debug->buffer = vmalloc(MAX_DEBUGFS_RX_TABLE_SIZE);
+ debug->buffer = vmalloc(MAX_DEBUGFS_RX_INFO_SIZE);
if (!debug->buffer) {
kfree(debug);
goto out;
@@ -5552,57 +5552,18 @@ lpfc_rx_monitor_read(struct file *file,
struct lpfc_rx_monitor_debug *debug = file->private_data;
struct lpfc_hba *phba = (struct lpfc_hba *)debug->i_private;
char *buffer = debug->buffer;
- struct rxtable_entry *entry;
- int i, len = 0, head, tail, last, start;

- head = atomic_read(&phba->rxtable_idx_head);
- while (head == LPFC_RXMONITOR_TABLE_IN_USE) {
- /* Table is getting updated */
- msleep(20);
- head = atomic_read(&phba->rxtable_idx_head);
+ if (!phba->rx_monitor) {
+ scnprintf(buffer, MAX_DEBUGFS_RX_INFO_SIZE,
+ "Rx Monitor Info is empty.\n");
+ } else {
+ lpfc_rx_monitor_report(phba, phba->rx_monitor, buffer,
+ MAX_DEBUGFS_RX_INFO_SIZE,
+ LPFC_MAX_RXMONITOR_ENTRY);
}

- tail = atomic_xchg(&phba->rxtable_idx_tail, head);
- if (!phba->rxtable || head == tail) {
- len += scnprintf(buffer + len, MAX_DEBUGFS_RX_TABLE_SIZE - len,
- "Rxtable is empty\n");
- goto out;
- }
- last = (head > tail) ? head : LPFC_MAX_RXMONITOR_ENTRY;
- start = tail;
-
- len += scnprintf(buffer + len, MAX_DEBUGFS_RX_TABLE_SIZE - len,
- " MaxBPI Tot_Data_CMF Tot_Data_Cmd "
- "Tot_Data_Cmpl Lat(us) Avg_IO Max_IO "
- "Bsy IO_cnt Info BWutil(ms)\n");
-get_table:
- for (i = start; i < last; i++) {
- entry = &phba->rxtable[i];
- len += scnprintf(buffer + len, MAX_DEBUGFS_RX_TABLE_SIZE - len,
- "%3d:%12lld %12lld %12lld %12lld "
- "%7lldus %8lld %7lld "
- "%2d %4d %2d %2d(%2d)\n",
- i, entry->max_bytes_per_interval,
- entry->cmf_bytes,
- entry->total_bytes,
- entry->rcv_bytes,
- entry->avg_io_latency,
- entry->avg_io_size,
- entry->max_read_cnt,
- entry->cmf_busy,
- entry->io_cnt,
- entry->cmf_info,
- entry->timer_utilization,
- entry->timer_interval);
- }
-
- if (head != last) {
- start = 0;
- last = head;
- goto get_table;
- }
-out:
- return simple_read_from_buffer(buf, nbytes, ppos, buffer, len);
+ return simple_read_from_buffer(buf, nbytes, ppos, buffer,
+ strlen(buffer));
}

static int
--- a/drivers/scsi/lpfc/lpfc_debugfs.h
+++ b/drivers/scsi/lpfc/lpfc_debugfs.h
@@ -282,7 +282,7 @@ struct lpfc_idiag {
void *ptr_private;
};

-#define MAX_DEBUGFS_RX_TABLE_SIZE (128 * LPFC_MAX_RXMONITOR_ENTRY)
+#define MAX_DEBUGFS_RX_INFO_SIZE (128 * LPFC_MAX_RXMONITOR_ENTRY)
struct lpfc_rx_monitor_debug {
char *i_private;
char *buffer;
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -5571,38 +5571,12 @@ lpfc_async_link_speed_to_read_top(struct
void
lpfc_cgn_dump_rxmonitor(struct lpfc_hba *phba)
{
- struct rxtable_entry *entry;
- int cnt = 0, head, tail, last, start;
-
- head = atomic_read(&phba->rxtable_idx_head);
- tail = atomic_read(&phba->rxtable_idx_tail);
- if (!phba->rxtable || head == tail) {
- lpfc_printf_log(phba, KERN_ERR, LOG_CGN_MGMT,
- "4411 Rxtable is empty\n");
- return;
- }
- last = tail;
- start = head;
-
- /* Display the last LPFC_MAX_RXMONITOR_DUMP entries from the rxtable */
- while (start != last) {
- if (start)
- start--;
- else
- start = LPFC_MAX_RXMONITOR_ENTRY - 1;
- entry = &phba->rxtable[start];
+ if (!phba->rx_monitor) {
lpfc_printf_log(phba, KERN_INFO, LOG_CGN_MGMT,
- "4410 %02d: MBPI %lld Xmit %lld Cmpl %lld "
- "Lat %lld ASz %lld Info %02d BWUtil %d "
- "Int %d slot %d\n",
- cnt, entry->max_bytes_per_interval,
- entry->total_bytes, entry->rcv_bytes,
- entry->avg_io_latency, entry->avg_io_size,
- entry->cmf_info, entry->timer_utilization,
- entry->timer_interval, start);
- cnt++;
- if (cnt >= LPFC_MAX_RXMONITOR_DUMP)
- return;
+ "4411 Rx Monitor Info is empty.\n");
+ } else {
+ lpfc_rx_monitor_report(phba, phba->rx_monitor, NULL, 0,
+ LPFC_MAX_RXMONITOR_DUMP);
}
}

@@ -6009,9 +5983,8 @@ lpfc_cmf_timer(struct hrtimer *timer)
{
struct lpfc_hba *phba = container_of(timer, struct lpfc_hba,
cmf_timer);
- struct rxtable_entry *entry;
+ struct rx_info_entry entry;
uint32_t io_cnt;
- uint32_t head, tail;
uint32_t busy, max_read;
uint64_t total, rcv, lat, mbpi, extra, cnt;
int timer_interval = LPFC_CMF_INTERVAL;
@@ -6131,40 +6104,30 @@ lpfc_cmf_timer(struct hrtimer *timer)
}

/* Save rxmonitor information for debug */
- if (phba->rxtable) {
- head = atomic_xchg(&phba->rxtable_idx_head,
- LPFC_RXMONITOR_TABLE_IN_USE);
- entry = &phba->rxtable[head];
- entry->total_bytes = total;
- entry->cmf_bytes = total + extra;
- entry->rcv_bytes = rcv;
- entry->cmf_busy = busy;
- entry->cmf_info = phba->cmf_active_info;
+ if (phba->rx_monitor) {
+ entry.total_bytes = total;
+ entry.cmf_bytes = total + extra;
+ entry.rcv_bytes = rcv;
+ entry.cmf_busy = busy;
+ entry.cmf_info = phba->cmf_active_info;
if (io_cnt) {
- entry->avg_io_latency = div_u64(lat, io_cnt);
- entry->avg_io_size = div_u64(rcv, io_cnt);
+ entry.avg_io_latency = div_u64(lat, io_cnt);
+ entry.avg_io_size = div_u64(rcv, io_cnt);
} else {
- entry->avg_io_latency = 0;
- entry->avg_io_size = 0;
+ entry.avg_io_latency = 0;
+ entry.avg_io_size = 0;
}
- entry->max_read_cnt = max_read;
- entry->io_cnt = io_cnt;
- entry->max_bytes_per_interval = mbpi;
+ entry.max_read_cnt = max_read;
+ entry.io_cnt = io_cnt;
+ entry.max_bytes_per_interval = mbpi;
if (phba->cmf_active_mode == LPFC_CFG_MANAGED)
- entry->timer_utilization = phba->cmf_last_ts;
+ entry.timer_utilization = phba->cmf_last_ts;
else
- entry->timer_utilization = ms;
- entry->timer_interval = ms;
+ entry.timer_utilization = ms;
+ entry.timer_interval = ms;
phba->cmf_last_ts = 0;

- /* Increment rxtable index */
- head = (head + 1) % LPFC_MAX_RXMONITOR_ENTRY;
- tail = atomic_read(&phba->rxtable_idx_tail);
- if (head == tail) {
- tail = (tail + 1) % LPFC_MAX_RXMONITOR_ENTRY;
- atomic_set(&phba->rxtable_idx_tail, tail);
- }
- atomic_set(&phba->rxtable_idx_head, head);
+ lpfc_rx_monitor_record(phba->rx_monitor, &entry);
}

if (phba->cmf_active_mode == LPFC_CFG_MONITOR) {
--- a/drivers/scsi/lpfc/lpfc_mem.c
+++ b/drivers/scsi/lpfc/lpfc_mem.c
@@ -344,9 +344,12 @@ lpfc_mem_free_all(struct lpfc_hba *phba)
phba->cgn_i = NULL;
}

- /* Free RX table */
- kfree(phba->rxtable);
- phba->rxtable = NULL;
+ /* Free RX Monitor */
+ if (phba->rx_monitor) {
+ lpfc_rx_monitor_destroy_ring(phba->rx_monitor);
+ kfree(phba->rx_monitor);
+ phba->rx_monitor = NULL;
+ }

/* Free the iocb lookup array */
kfree(psli->iocbq_lookup);
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -7955,6 +7955,172 @@ static void lpfc_sli4_dip(struct lpfc_hb
}

/**
+ * lpfc_rx_monitor_create_ring - Initialize ring buffer for rx_monitor
+ * @rx_monitor: Pointer to lpfc_rx_info_monitor object
+ * @entries: Number of rx_info_entry objects to allocate in ring
+ *
+ * Return:
+ * 0 - Success
+ * ENOMEM - Failure to kmalloc
+ **/
+int lpfc_rx_monitor_create_ring(struct lpfc_rx_info_monitor *rx_monitor,
+ u32 entries)
+{
+ rx_monitor->ring = kmalloc_array(entries, sizeof(struct rx_info_entry),
+ GFP_KERNEL);
+ if (!rx_monitor->ring)
+ return -ENOMEM;
+
+ rx_monitor->head_idx = 0;
+ rx_monitor->tail_idx = 0;
+ spin_lock_init(&rx_monitor->lock);
+ rx_monitor->entries = entries;
+
+ return 0;
+}
+
+/**
+ * lpfc_rx_monitor_destroy_ring - Free ring buffer for rx_monitor
+ * @rx_monitor: Pointer to lpfc_rx_info_monitor object
+ **/
+void lpfc_rx_monitor_destroy_ring(struct lpfc_rx_info_monitor *rx_monitor)
+{
+ spin_lock(&rx_monitor->lock);
+ kfree(rx_monitor->ring);
+ rx_monitor->ring = NULL;
+ rx_monitor->entries = 0;
+ rx_monitor->head_idx = 0;
+ rx_monitor->tail_idx = 0;
+ spin_unlock(&rx_monitor->lock);
+}
+
+/**
+ * lpfc_rx_monitor_record - Insert an entry into rx_monitor's ring
+ * @rx_monitor: Pointer to lpfc_rx_info_monitor object
+ * @entry: Pointer to rx_info_entry
+ *
+ * Used to insert an rx_info_entry into rx_monitor's ring. Note that this is a
+ * deep copy of rx_info_entry not a shallow copy of the rx_info_entry ptr.
+ *
+ * This is called from lpfc_cmf_timer, which is in timer/softirq context.
+ *
+ * In cases of old data overflow, we do a best effort of FIFO order.
+ **/
+void lpfc_rx_monitor_record(struct lpfc_rx_info_monitor *rx_monitor,
+ struct rx_info_entry *entry)
+{
+ struct rx_info_entry *ring = rx_monitor->ring;
+ u32 *head_idx = &rx_monitor->head_idx;
+ u32 *tail_idx = &rx_monitor->tail_idx;
+ spinlock_t *ring_lock = &rx_monitor->lock;
+ u32 ring_size = rx_monitor->entries;
+
+ spin_lock(ring_lock);
+ memcpy(&ring[*tail_idx], entry, sizeof(*entry));
+ *tail_idx = (*tail_idx + 1) % ring_size;
+
+ /* Best effort of FIFO saved data */
+ if (*tail_idx == *head_idx)
+ *head_idx = (*head_idx + 1) % ring_size;
+
+ spin_unlock(ring_lock);
+}
+
+/**
+ * lpfc_rx_monitor_report - Read out rx_monitor's ring
+ * @phba: Pointer to lpfc_hba object
+ * @rx_monitor: Pointer to lpfc_rx_info_monitor object
+ * @buf: Pointer to char buffer that will contain rx monitor info data
+ * @buf_len: Length buf including null char
+ * @max_read_entries: Maximum number of entries to read out of ring
+ *
+ * Used to dump/read what's in rx_monitor's ring buffer.
+ *
+ * If buf is NULL || buf_len == 0, then it is implied that we want to log the
+ * information to kmsg instead of filling out buf.
+ *
+ * Return:
+ * Number of entries read out of the ring
+ **/
+u32 lpfc_rx_monitor_report(struct lpfc_hba *phba,
+ struct lpfc_rx_info_monitor *rx_monitor, char *buf,
+ u32 buf_len, u32 max_read_entries)
+{
+ struct rx_info_entry *ring = rx_monitor->ring;
+ struct rx_info_entry *entry;
+ u32 *head_idx = &rx_monitor->head_idx;
+ u32 *tail_idx = &rx_monitor->tail_idx;
+ spinlock_t *ring_lock = &rx_monitor->lock;
+ u32 ring_size = rx_monitor->entries;
+ u32 cnt = 0;
+ char tmp[DBG_LOG_STR_SZ] = {0};
+ bool log_to_kmsg = (!buf || !buf_len) ? true : false;
+
+ if (!log_to_kmsg) {
+ /* clear the buffer to be sure */
+ memset(buf, 0, buf_len);
+
+ scnprintf(buf, buf_len, "\t%-16s%-16s%-16s%-16s%-8s%-8s%-8s"
+ "%-8s%-8s%-8s%-16s\n",
+ "MaxBPI", "Tot_Data_CMF",
+ "Tot_Data_Cmd", "Tot_Data_Cmpl",
+ "Lat(us)", "Avg_IO", "Max_IO", "Bsy",
+ "IO_cnt", "Info", "BWutil(ms)");
+ }
+
+ /* Needs to be _bh because record is called from timer interrupt
+ * context
+ */
+ spin_lock_bh(ring_lock);
+ while (*head_idx != *tail_idx) {
+ entry = &ring[*head_idx];
+
+ /* Read out this entry's data. */
+ if (!log_to_kmsg) {
+ /* If !log_to_kmsg, then store to buf. */
+ scnprintf(tmp, sizeof(tmp),
+ "%03d:\t%-16llu%-16llu%-16llu%-16llu%-8llu"
+ "%-8llu%-8llu%-8u%-8u%-8u%u(%u)\n",
+ *head_idx, entry->max_bytes_per_interval,
+ entry->cmf_bytes, entry->total_bytes,
+ entry->rcv_bytes, entry->avg_io_latency,
+ entry->avg_io_size, entry->max_read_cnt,
+ entry->cmf_busy, entry->io_cnt,
+ entry->cmf_info, entry->timer_utilization,
+ entry->timer_interval);
+
+ /* Check for buffer overflow */
+ if ((strlen(buf) + strlen(tmp)) >= buf_len)
+ break;
+
+ /* Append entry's data to buffer */
+ strlcat(buf, tmp, buf_len);
+ } else {
+ lpfc_printf_log(phba, KERN_INFO, LOG_CGN_MGMT,
+ "4410 %02u: MBPI %llu Xmit %llu "
+ "Cmpl %llu Lat %llu ASz %llu Info %02u "
+ "BWUtil %u Int %u slot %u\n",
+ cnt, entry->max_bytes_per_interval,
+ entry->total_bytes, entry->rcv_bytes,
+ entry->avg_io_latency,
+ entry->avg_io_size, entry->cmf_info,
+ entry->timer_utilization,
+ entry->timer_interval, *head_idx);
+ }
+
+ *head_idx = (*head_idx + 1) % ring_size;
+
+ /* Don't feed more than max_read_entries */
+ cnt++;
+ if (cnt >= max_read_entries)
+ break;
+ }
+ spin_unlock_bh(ring_lock);
+
+ return cnt;
+}
+
+/**
* lpfc_cmf_setup - Initialize idle_stat tracking
* @phba: Pointer to HBA context object.
*
@@ -8128,19 +8294,29 @@ no_cmf:
phba->cmf_interval_rate = LPFC_CMF_INTERVAL;

/* Allocate RX Monitor Buffer */
- if (!phba->rxtable) {
- phba->rxtable = kmalloc_array(LPFC_MAX_RXMONITOR_ENTRY,
- sizeof(struct rxtable_entry),
- GFP_KERNEL);
- if (!phba->rxtable) {
+ if (!phba->rx_monitor) {
+ phba->rx_monitor = kzalloc(sizeof(*phba->rx_monitor),
+ GFP_KERNEL);
+
+ if (!phba->rx_monitor) {
lpfc_printf_log(phba, KERN_ERR, LOG_INIT,
"2644 Failed to alloc memory "
"for RX Monitor Buffer\n");
return -ENOMEM;
}
+
+ /* Instruct the rx_monitor object to instantiate its ring */
+ if (lpfc_rx_monitor_create_ring(phba->rx_monitor,
+ LPFC_MAX_RXMONITOR_ENTRY)) {
+ kfree(phba->rx_monitor);
+ phba->rx_monitor = NULL;
+ lpfc_printf_log(phba, KERN_ERR, LOG_INIT,
+ "2645 Failed to alloc memory "
+ "for RX Monitor's Ring\n");
+ return -ENOMEM;
+ }
}
- atomic_set(&phba->rxtable_idx_head, 0);
- atomic_set(&phba->rxtable_idx_tail, 0);
+
return 0;
}