[PATCH net-next v4 3/7] net: stmmac: refactor FPE verification process

Furong Xu
2024-08-20T09:41:49Z

Drop driver defined stmmac_fpe_state, and switch to common
ethtool_mm_verify_status for local TX verification status.

Local side and remote side verification processes are completely
independent. There is no reason at all to keep a local state and
a remote state.

Add a spinlock to avoid races among ISR, workqueue, link update
and register configuration.

Signed-off-by: Furong Xu <0x1207@gmail.com>
---
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 21 +--
.../net/ethernet/stmicro/stmmac/stmmac_main.c | 172 ++++++++++--------
.../net/ethernet/stmicro/stmmac/stmmac_tc.c | 6 -
3 files changed, 102 insertions(+), 97 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 458d6b16ce21..407b59f2783f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -146,14 +146,6 @@ struct stmmac_channel {
u32 index;
};

-/* FPE link state */
-enum stmmac_fpe_state {
- FPE_STATE_OFF = 0,
- FPE_STATE_CAPABLE = 1,
- FPE_STATE_ENTERING_ON = 2,
- FPE_STATE_ON = 3,
-};
-
/* FPE link-partner hand-shaking mPacket type */
enum stmmac_mpacket_type {
MPACKET_VERIFY = 0,
@@ -166,11 +158,16 @@ enum stmmac_fpe_task_state_t {
};

struct stmmac_fpe_cfg {
- bool enable; /* FPE enable */
- bool hs_enable; /* FPE handshake enable */
- enum stmmac_fpe_state lp_fpe_state; /* Link Partner FPE state */
- enum stmmac_fpe_state lo_fpe_state; /* Local station FPE state */
+ /* Serialize access to MAC Merge state between ethtool requests
+ * and link state updates.
+ */
+ spinlock_t lock;
+
u32 fpe_csr; /* MAC_FPE_CTRL_STS reg cache */
+ u32 verify_time; /* see ethtool_mm_state */
+ bool pmac_enabled; /* see ethtool_mm_state */
+ bool verify_enabled; /* see ethtool_mm_state */
+ enum ethtool_mm_verify_status status;
};

struct stmmac_tc_entry {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 3072ad33b105..6ae95f20b24f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -969,17 +969,21 @@ static void stmmac_mac_config(struct phylink_config *config, unsigned int mode,
static void stmmac_fpe_link_state_handle(struct stmmac_priv *priv, bool is_up)
{
struct stmmac_fpe_cfg *fpe_cfg = &priv->fpe_cfg;
- enum stmmac_fpe_state *lo_state = &fpe_cfg->lo_fpe_state;
- enum stmmac_fpe_state *lp_state = &fpe_cfg->lp_fpe_state;
- bool *hs_enable = &fpe_cfg->hs_enable;
+ unsigned long flags;
+
+ spin_lock_irqsave(&priv->fpe_cfg.lock, flags);
+
+ if (!fpe_cfg->pmac_enabled)
+ goto __unlock_out;

- if (is_up && *hs_enable) {
+ if (is_up && fpe_cfg->verify_enabled)
stmmac_fpe_send_mpacket(priv, priv->ioaddr, fpe_cfg,
MPACKET_VERIFY);
- } else {
- *lo_state = FPE_STATE_OFF;
- *lp_state = FPE_STATE_OFF;
- }
+ else
+ fpe_cfg->status = ETHTOOL_MM_VERIFY_STATUS_DISABLED;
+
+__unlock_out:
+ spin_unlock_irqrestore(&priv->fpe_cfg.lock, flags);
}

static void stmmac_mac_link_down(struct phylink_config *config,
@@ -4091,11 +4095,25 @@ static int stmmac_release(struct net_device *dev)

stmmac_release_ptp(priv);

- pm_runtime_put(priv->device);
-
- if (priv->dma_cap.fpesel)
+ if (priv->dma_cap.fpesel) {
stmmac_fpe_stop_wq(priv);

+ /* stmmac_ethtool_ops.begin() guarantees that all ethtool
+ * requests to fail with EBUSY when !netif_running()
+ *
+ * Prepare some params here, then fpe_cfg can keep consistent
+ * with the register states after a SW reset by __stmmac_open().
+ */
+ priv->fpe_cfg.pmac_enabled = false;
+ priv->fpe_cfg.verify_enabled = false;
+ priv->fpe_cfg.status = ETHTOOL_MM_VERIFY_STATUS_DISABLED;
+
+ /* Reset MAC_FPE_CTRL_STS reg cache */
+ priv->fpe_cfg.fpe_csr = 0;
+ }
+
+ pm_runtime_put(priv->device);
+
return 0;
}

@@ -5979,44 +5997,34 @@ static int stmmac_set_features(struct net_device *netdev,
static void stmmac_fpe_event_status(struct stmmac_priv *priv, int status)
{
struct stmmac_fpe_cfg *fpe_cfg = &priv->fpe_cfg;
- enum stmmac_fpe_state *lo_state = &fpe_cfg->lo_fpe_state;
- enum stmmac_fpe_state *lp_state = &fpe_cfg->lp_fpe_state;
- bool *hs_enable = &fpe_cfg->hs_enable;

- if (status == FPE_EVENT_UNKNOWN || !*hs_enable)
- return;
+ spin_lock(&priv->fpe_cfg.lock);

- /* If LP has sent verify mPacket, LP is FPE capable */
- if ((status & FPE_EVENT_RVER) == FPE_EVENT_RVER) {
- if (*lp_state < FPE_STATE_CAPABLE)
- *lp_state = FPE_STATE_CAPABLE;
+ if (!fpe_cfg->pmac_enabled || status == FPE_EVENT_UNKNOWN)
+ goto __unlock_out;

- /* If user has requested FPE enable, quickly response */
- if (*hs_enable)
- stmmac_fpe_send_mpacket(priv, priv->ioaddr,
- fpe_cfg,
- MPACKET_RESPONSE);
- }
+ /* LP has sent verify mPacket */
+ if ((status & FPE_EVENT_RVER) == FPE_EVENT_RVER)
+ stmmac_fpe_send_mpacket(priv, priv->ioaddr, fpe_cfg,
+ MPACKET_RESPONSE);

- /* If Local has sent verify mPacket, Local is FPE capable */
- if ((status & FPE_EVENT_TVER) == FPE_EVENT_TVER) {
- if (*lo_state < FPE_STATE_CAPABLE)
- *lo_state = FPE_STATE_CAPABLE;
- }
+ /* Local has sent verify mPacket */
+ if ((status & FPE_EVENT_TVER) == FPE_EVENT_TVER &&
+ fpe_cfg->status != ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED)
+ fpe_cfg->status = ETHTOOL_MM_VERIFY_STATUS_VERIFYING;

- /* If LP has sent response mPacket, LP is entering FPE ON */
+ /* LP has sent response mPacket */
if ((status & FPE_EVENT_RRSP) == FPE_EVENT_RRSP)
- *lp_state = FPE_STATE_ENTERING_ON;
-
- /* If Local has sent response mPacket, Local is entering FPE ON */
- if ((status & FPE_EVENT_TRSP) == FPE_EVENT_TRSP)
- *lo_state = FPE_STATE_ENTERING_ON;
+ fpe_cfg->status = ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED;

if (!test_bit(__FPE_REMOVING, &priv->fpe_task_state) &&
!test_and_set_bit(__FPE_TASK_SCHED, &priv->fpe_task_state) &&
priv->fpe_wq) {
queue_work(priv->fpe_wq, &priv->fpe_task);
}
+
+__unlock_out:
+ spin_unlock(&priv->fpe_cfg.lock);
}

static void stmmac_common_interrupt(struct stmmac_priv *priv)
@@ -7372,50 +7380,57 @@ int stmmac_reinit_ringparam(struct net_device *dev, u32 rx_size, u32 tx_size)
return ret;
}

-#define SEND_VERIFY_MPAKCET_FMT "Send Verify mPacket lo_state=%d lp_state=%d\n"
-static void stmmac_fpe_lp_task(struct work_struct *work)
+static void stmmac_fpe_verify_task(struct work_struct *work)
{
struct stmmac_priv *priv = container_of(work, struct stmmac_priv,
fpe_task);
struct stmmac_fpe_cfg *fpe_cfg = &priv->fpe_cfg;
- enum stmmac_fpe_state *lo_state = &fpe_cfg->lo_fpe_state;
- enum stmmac_fpe_state *lp_state = &fpe_cfg->lp_fpe_state;
- bool *hs_enable = &fpe_cfg->hs_enable;
- bool *enable = &fpe_cfg->enable;
- int retries = 20;
-
- while (retries-- > 0) {
- /* Bail out immediately if FPE handshake is OFF */
- if (*lo_state == FPE_STATE_OFF || !*hs_enable)
+ int verify_limit = 3; /* defined by 802.3 */
+ unsigned long flags;
+ u32 sleep_ms;
+
+ spin_lock(&priv->fpe_cfg.lock);
+ sleep_ms = fpe_cfg->verify_time;
+ spin_unlock(&priv->fpe_cfg.lock);
+
+ while (1) {
+ /* The initial VERIFY was triggered by linkup event or
+ * stmmac_set_mm(), sleep then check MM_VERIFY_STATUS.
+ */
+ msleep(sleep_ms);
+
+ if (!netif_running(priv->dev))
break;

- if (*lo_state == FPE_STATE_ENTERING_ON &&
- *lp_state == FPE_STATE_ENTERING_ON) {
- stmmac_fpe_configure(priv, priv->ioaddr,
- fpe_cfg,
- priv->plat->tx_queues_to_use,
- priv->plat->rx_queues_to_use,
- *enable);
+ spin_lock_irqsave(&priv->fpe_cfg.lock, flags);

- netdev_info(priv->dev, "configured FPE\n");
+ if (fpe_cfg->status == ETHTOOL_MM_VERIFY_STATUS_DISABLED ||
+ fpe_cfg->status == ETHTOOL_MM_VERIFY_STATUS_SUCCEEDED ||
+ !fpe_cfg->pmac_enabled || !fpe_cfg->verify_enabled) {
+ spin_unlock_irqrestore(&priv->fpe_cfg.lock, flags);
+ break;
+ }

- *lo_state = FPE_STATE_ON;
- *lp_state = FPE_STATE_ON;
- netdev_info(priv->dev, "!!! BOTH FPE stations ON\n");
+ if (verify_limit == 0) {
+ fpe_cfg->verify_enabled = false;
+ fpe_cfg->status = ETHTOOL_MM_VERIFY_STATUS_FAILED;
+ stmmac_fpe_configure(priv, priv->ioaddr, fpe_cfg,
+ priv->plat->tx_queues_to_use,
+ priv->plat->rx_queues_to_use,
+ false);
+ spin_unlock_irqrestore(&priv->fpe_cfg.lock, flags);
break;
}

- if ((*lo_state == FPE_STATE_CAPABLE ||
- *lo_state == FPE_STATE_ENTERING_ON) &&
- *lp_state != FPE_STATE_ON) {
- netdev_info(priv->dev, SEND_VERIFY_MPAKCET_FMT,
- *lo_state, *lp_state);
- stmmac_fpe_send_mpacket(priv, priv->ioaddr,
- fpe_cfg,
+ if (fpe_cfg->status == ETHTOOL_MM_VERIFY_STATUS_VERIFYING)
+ stmmac_fpe_send_mpacket(priv, priv->ioaddr, fpe_cfg,
MPACKET_VERIFY);
- }
- /* Sleep then retry */
- msleep(500);
+
+ sleep_ms = fpe_cfg->verify_time;
+
+ spin_unlock_irqrestore(&priv->fpe_cfg.lock, flags);
+
+ verify_limit--;
}

clear_bit(__FPE_TASK_SCHED, &priv->fpe_task_state);
@@ -7535,8 +7550,8 @@ int stmmac_dvr_probe(struct device *device,

INIT_WORK(&priv->service_task, stmmac_service_task);

- /* Initialize Link Partner FPE workqueue */
- INIT_WORK(&priv->fpe_task, stmmac_fpe_lp_task);
+ /* Initialize FPE verify workqueue */
+ INIT_WORK(&priv->fpe_task, stmmac_fpe_verify_task);

/* Override with kernel parameters if supplied XXX CRS XXX
* this needs to have multiple instances
@@ -7702,6 +7717,12 @@ int stmmac_dvr_probe(struct device *device,

mutex_init(&priv->lock);

+ spin_lock_init(&priv->fpe_cfg.lock);
+ priv->fpe_cfg.pmac_enabled = false;
+ priv->fpe_cfg.verify_time = 128; /* ethtool_mm_state.max_verify_time */
+ priv->fpe_cfg.verify_enabled = false;
+ priv->fpe_cfg.status = ETHTOOL_MM_VERIFY_STATUS_DISABLED;
+
/* If a specific clk_csr value is passed from the platform
* this means that the CSR Clock Range selection cannot be
* changed at run-time and it is fixed. Viceversa the driver'll try to
@@ -7875,15 +7896,8 @@ int stmmac_suspend(struct device *dev)
}
rtnl_unlock();

- if (priv->dma_cap.fpesel) {
- /* Disable FPE */
- stmmac_fpe_configure(priv, priv->ioaddr,
- &priv->fpe_cfg,
- priv->plat->tx_queues_to_use,
- priv->plat->rx_queues_to_use, false);
-
+ if (priv->dma_cap.fpesel)
stmmac_fpe_stop_wq(priv);
- }

priv->speed = SPEED_UNKNOWN;
return 0;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
index b0cc45331ff7..783829a6479c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -1063,11 +1063,6 @@ static int tc_taprio_configure(struct stmmac_priv *priv,
return -EOPNOTSUPP;
}

- /* Actual FPE register configuration will be done after FPE handshake
- * is success.
- */
- priv->fpe_cfg.enable = fpe;
-
ret = stmmac_est_configure(priv, priv, priv->est,
priv->plat->clk_ptp_rate);
mutex_unlock(&priv->est_lock);
@@ -1094,7 +1089,6 @@ static int tc_taprio_configure(struct stmmac_priv *priv,
mutex_unlock(&priv->est_lock);
}

- priv->fpe_cfg.enable = false;
stmmac_fpe_configure(priv, priv->ioaddr,
&priv->fpe_cfg,
priv->plat->tx_queues_to_use,
--
2.34.1