sfc: Add support for MCDI v2

MCDI v2 adds a second header dword with wider command and length
fields.  It also defines extra error codes.

Change the fallback error number for unknown MCDI error codes from EIO
to EPROTO.  EIO is treated as indicating the MCDI transport has failed
and we need to reset the function, which is rather drastic.

v2 error codes and lengths don't fit into completion events, so for a
v2-capable transport, always read the response header rather then
using the event fields.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

6 files changed, 127 insertions, 55 deletions

diff --git a/drivers/net/ethernet/sfc/falcon.c b/drivers/net/ethernet/sfc/falcon.c
index fe83c26..e556a5d 100644
--- a/drivers/net/ethernet/sfc/falcon.c
+++ b/drivers/net/ethernet/sfc/falcon.c
@@ -2404,6 +2404,7 @@ const struct efx_nic_type falcon_a1_nic_type = {
 	.phys_addr_channels = 4,
 	.timer_period_max =  1 << FRF_AB_TC_TIMER_VAL_WIDTH,
 	.offload_features = NETIF_F_IP_CSUM,
+	.mcdi_max_ver = -1,
 };
 
 const struct efx_nic_type falcon_b0_nic_type = {
@@ -2481,5 +2482,6 @@ const struct efx_nic_type falcon_b0_nic_type = {
 				   * channels */
 	.timer_period_max =  1 << FRF_AB_TC_TIMER_VAL_WIDTH,
 	.offload_features = NETIF_F_IP_CSUM | NETIF_F_RXHASH | NETIF_F_NTUPLE,
+	.mcdi_max_ver = -1,
 };
 
diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index c6c5830..2c5ee89 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -72,26 +72,44 @@ static void efx_mcdi_copyin(struct efx_nic *efx, unsigned cmd,
 			    const efx_dword_t *inbuf, size_t inlen)
 {
 	struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
-	efx_dword_t hdr;
+	efx_dword_t hdr[2];
+	size_t hdr_len;
 	u32 xflags, seqno;
 
 	BUG_ON(atomic_read(&mcdi->state) == MCDI_STATE_QUIESCENT);
-	BUG_ON(inlen > MCDI_CTL_SDU_LEN_MAX_V1);
 
 	seqno = mcdi->seqno & SEQ_MASK;
 	xflags = 0;
 	if (mcdi->mode == MCDI_MODE_EVENTS)
 		xflags |= MCDI_HEADER_XFLAGS_EVREQ;
 
-	EFX_POPULATE_DWORD_6(hdr,
-			     MCDI_HEADER_RESPONSE, 0,
-			     MCDI_HEADER_RESYNC, 1,
-			     MCDI_HEADER_CODE, cmd,
-			     MCDI_HEADER_DATALEN, inlen,
-			     MCDI_HEADER_SEQ, seqno,
-			     MCDI_HEADER_XFLAGS, xflags);
+	if (efx->type->mcdi_max_ver == 1) {
+		/* MCDI v1 */
+		EFX_POPULATE_DWORD_6(hdr[0],
+				     MCDI_HEADER_RESPONSE, 0,
+				     MCDI_HEADER_RESYNC, 1,
+				     MCDI_HEADER_CODE, cmd,
+				     MCDI_HEADER_DATALEN, inlen,
+				     MCDI_HEADER_SEQ, seqno,
+				     MCDI_HEADER_XFLAGS, xflags);
+		hdr_len = 4;
+	} else {
+		/* MCDI v2 */
+		BUG_ON(inlen > MCDI_CTL_SDU_LEN_MAX_V2);
+		EFX_POPULATE_DWORD_6(hdr[0],
+				     MCDI_HEADER_RESPONSE, 0,
+				     MCDI_HEADER_RESYNC, 1,
+				     MCDI_HEADER_CODE, MC_CMD_V2_EXTN,
+				     MCDI_HEADER_DATALEN, 0,
+				     MCDI_HEADER_SEQ, seqno,
+				     MCDI_HEADER_XFLAGS, xflags);
+		EFX_POPULATE_DWORD_2(hdr[1],
+				     MC_CMD_V2_EXTN_IN_EXTENDED_CMD, cmd,
+				     MC_CMD_V2_EXTN_IN_ACTUAL_LEN, inlen);
+		hdr_len = 8;
+	}
 
-	efx->type->mcdi_request(efx, &hdr, 4, inbuf, inlen);
+	efx->type->mcdi_request(efx, hdr, hdr_len, inbuf, inlen);
 }
 
 static void
@@ -100,9 +118,8 @@ efx_mcdi_copyout(struct efx_nic *efx, efx_dword_t *outbuf, size_t outlen)
 	struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
 
 	BUG_ON(atomic_read(&mcdi->state) == MCDI_STATE_QUIESCENT);
-	BUG_ON(outlen > MCDI_CTL_SDU_LEN_MAX_V1);
 
-	efx->type->mcdi_read_response(efx, outbuf, 4, outlen);
+	efx->type->mcdi_read_response(efx, outbuf, mcdi->resp_hdr_len, outlen);
 }
 
 static int efx_mcdi_errno(unsigned int mcdi_err)
@@ -113,17 +130,63 @@ static int efx_mcdi_errno(unsigned int mcdi_err)
 #define TRANSLATE_ERROR(name)					\
 	case MC_CMD_ERR_ ## name:				\
 		return -name;
+	TRANSLATE_ERROR(EPERM);
 	TRANSLATE_ERROR(ENOENT);
 	TRANSLATE_ERROR(EINTR);
+	TRANSLATE_ERROR(EAGAIN);
 	TRANSLATE_ERROR(EACCES);
 	TRANSLATE_ERROR(EBUSY);
 	TRANSLATE_ERROR(EINVAL);
 	TRANSLATE_ERROR(EDEADLK);
 	TRANSLATE_ERROR(ENOSYS);
 	TRANSLATE_ERROR(ETIME);
+	TRANSLATE_ERROR(EALREADY);
+	TRANSLATE_ERROR(ENOSPC);
 #undef TRANSLATE_ERROR
+	case MC_CMD_ERR_ALLOC_FAIL:
+		return -ENOBUFS;
+	case MC_CMD_ERR_MAC_EXIST:
+		return -EADDRINUSE;
 	default:
-		return -EIO;
+		return -EPROTO;
+	}
+}
+
+static void efx_mcdi_read_response_header(struct efx_nic *efx)
+{
+	struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
+	unsigned int respseq, respcmd, error;
+	efx_dword_t hdr;
+
+	efx->type->mcdi_read_response(efx, &hdr, 0, 4);
+	respseq = EFX_DWORD_FIELD(hdr, MCDI_HEADER_SEQ);
+	respcmd = EFX_DWORD_FIELD(hdr, MCDI_HEADER_CODE);
+	error = EFX_DWORD_FIELD(hdr, MCDI_HEADER_ERROR);
+
+	if (respcmd != MC_CMD_V2_EXTN) {
+		mcdi->resp_hdr_len = 4;
+		mcdi->resp_data_len = EFX_DWORD_FIELD(hdr, MCDI_HEADER_DATALEN);
+	} else {
+		efx->type->mcdi_read_response(efx, &hdr, 4, 4);
+		mcdi->resp_hdr_len = 8;
+		mcdi->resp_data_len =
+			EFX_DWORD_FIELD(hdr, MC_CMD_V2_EXTN_IN_ACTUAL_LEN);
+	}
+
+	if (error && mcdi->resp_data_len == 0) {
+		netif_err(efx, hw, efx->net_dev, "MC rebooted\n");
+		mcdi->resprc = -EIO;
+	} else if ((respseq ^ mcdi->seqno) & SEQ_MASK) {
+		netif_err(efx, hw, efx->net_dev,
+			  "MC response mismatch tx seq 0x%x rx seq 0x%x\n",
+			  respseq, mcdi->seqno);
+		mcdi->resprc = -EIO;
+	} else if (error) {
+		efx->type->mcdi_read_response(efx, &hdr, mcdi->resp_hdr_len, 4);
+		mcdi->resprc =
+			efx_mcdi_errno(EFX_DWORD_FIELD(hdr, EFX_DWORD_0));
+	} else {
+		mcdi->resprc = 0;
 	}
 }
 
@@ -131,15 +194,17 @@ static int efx_mcdi_poll(struct efx_nic *efx)
 {
 	struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
 	unsigned long time, finish;
-	unsigned int respseq, respcmd, error;
 	unsigned int spins;
-	efx_dword_t reg;
 	int rc;
 
 	/* Check for a reboot atomically with respect to efx_mcdi_copyout() */
 	rc = efx_mcdi_poll_reboot(efx);
-	if (rc)
-		goto out;
+	if (rc) {
+		mcdi->resprc = rc;
+		mcdi->resp_hdr_len = 0;
+		mcdi->resp_data_len = 0;
+		return 0;
+	}
 
 	/* Poll for completion. Poll quickly (once a us) for the 1st jiffy,
 	 * because generally mcdi responses are fast. After that, back off
@@ -166,30 +231,7 @@ static int efx_mcdi_poll(struct efx_nic *efx)
 			return -ETIMEDOUT;
 	}
 
-	efx->type->mcdi_read_response(efx, &reg, 0, 4);
-	mcdi->resplen = EFX_DWORD_FIELD(reg, MCDI_HEADER_DATALEN);
-	respseq = EFX_DWORD_FIELD(reg, MCDI_HEADER_SEQ);
-	respcmd = EFX_DWORD_FIELD(reg, MCDI_HEADER_CODE);
-	error = EFX_DWORD_FIELD(reg, MCDI_HEADER_ERROR);
-
-	if (error && mcdi->resplen == 0) {
-		netif_err(efx, hw, efx->net_dev, "MC rebooted\n");
-		rc = -EIO;
-	} else if ((respseq ^ mcdi->seqno) & SEQ_MASK) {
-		netif_err(efx, hw, efx->net_dev,
-			  "MC response mismatch tx seq 0x%x rx seq 0x%x\n",
-			  respseq, mcdi->seqno);
-		rc = -EIO;
-	} else if (error) {
-		efx->type->mcdi_read_response(efx, &reg, 4, 4);
-		rc = efx_mcdi_errno(EFX_DWORD_FIELD(reg, EFX_DWORD_0));
-	} else
-		rc = 0;
-
-out:
-	mcdi->resprc = rc;
-	if (rc)
-		mcdi->resplen = 0;
+	efx_mcdi_read_response_header(efx);
 
 	/* Return rc=0 like wait_event_timeout() */
 	return 0;
@@ -293,8 +335,14 @@ static void efx_mcdi_ev_cpl(struct efx_nic *efx, unsigned int seqno,
 				  "MC response mismatch tx seq 0x%x rx "
 				  "seq 0x%x\n", seqno, mcdi->seqno);
 	} else {
-		mcdi->resprc = efx_mcdi_errno(mcdi_err);
-		mcdi->resplen = datalen;
+		if (efx->type->mcdi_max_ver >= 2) {
+			/* MCDI v2 responses don't fit in an event */
+			efx_mcdi_read_response_header(efx);
+		} else {
+			mcdi->resprc = efx_mcdi_errno(mcdi_err);
+			mcdi->resp_hdr_len = 4;
+			mcdi->resp_data_len = datalen;
+		}
 
 		wake = true;
 	}
@@ -310,16 +358,30 @@ int efx_mcdi_rpc(struct efx_nic *efx, unsigned cmd,
 		 efx_dword_t *outbuf, size_t outlen,
 		 size_t *outlen_actual)
 {
-	efx_mcdi_rpc_start(efx, cmd, inbuf, inlen);
+	int rc;
+
+	rc = efx_mcdi_rpc_start(efx, cmd, inbuf, inlen);
+	if (rc)
+		return rc;
 	return efx_mcdi_rpc_finish(efx, cmd, inlen,
 				   outbuf, outlen, outlen_actual);
 }
 
-void efx_mcdi_rpc_start(struct efx_nic *efx, unsigned cmd,
-			const efx_dword_t *inbuf, size_t inlen)
+int efx_mcdi_rpc_start(struct efx_nic *efx, unsigned cmd,
+		       const efx_dword_t *inbuf, size_t inlen)
 {
 	struct efx_mcdi_iface *mcdi = efx_mcdi(efx);
 
+	if (efx->type->mcdi_max_ver < 0 ||
+	     (efx->type->mcdi_max_ver < 2 &&
+	      cmd > MC_CMD_CMD_SPACE_ESCAPE_7))
+		return -EINVAL;
+
+	if (inlen > MCDI_CTL_SDU_LEN_MAX_V2 ||
+	    (efx->type->mcdi_max_ver < 2 &&
+	     inlen > MCDI_CTL_SDU_LEN_MAX_V1))
+		return -EMSGSIZE;
+
 	efx_mcdi_acquire(mcdi);
 
 	/* Serialise with efx_mcdi_ev_cpl() and efx_mcdi_ev_death() */
@@ -328,6 +390,7 @@ void efx_mcdi_rpc_start(struct efx_nic *efx, unsigned cmd,
 	spin_unlock_bh(&mcdi->iface_lock);
 
 	efx_mcdi_copyin(efx, cmd, inbuf, inlen);
+	return 0;
 }
 
 int efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
@@ -364,14 +427,14 @@ int efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
 		 * acquiring the iface_lock. */
 		spin_lock_bh(&mcdi->iface_lock);
 		rc = mcdi->resprc;
-		resplen = mcdi->resplen;
+		resplen = mcdi->resp_data_len;
 		spin_unlock_bh(&mcdi->iface_lock);
 
 		BUG_ON(rc > 0);
 
 		if (rc == 0) {
 			efx_mcdi_copyout(efx, outbuf,
-					 min(outlen, mcdi->resplen));
+					 min(outlen, mcdi->resp_data_len));
 			if (outlen_actual != NULL)
 				*outlen_actual = resplen;
 		} else if (cmd == MC_CMD_REBOOT && rc == -EIO)
@@ -467,7 +530,8 @@ static void efx_mcdi_ev_death(struct efx_nic *efx, int rc)
 	if (efx_mcdi_complete(mcdi)) {
 		if (mcdi->mode == MCDI_MODE_EVENTS) {
 			mcdi->resprc = rc;
-			mcdi->resplen = 0;
+			mcdi->resp_hdr_len = 0;
+			mcdi->resp_data_len = 0;
 			++mcdi->credits;
 		}
 	} else {
diff --git a/drivers/net/ethernet/sfc/mcdi.h b/drivers/net/ethernet/sfc/mcdi.h
index 9b536d0..0cb0d5a 100644
--- a/drivers/net/ethernet/sfc/mcdi.h
+++ b/drivers/net/ethernet/sfc/mcdi.h
@@ -43,7 +43,8 @@ enum efx_mcdi_mode {
  * @credits: Number of spurious MCDI completion events allowed before we
  *	trigger a fatal error. Protected by @lock
  * @resprc: Response error/success code (Linux numbering)
- * @resplen: Returned payload length
+ * @resp_hdr_len: Response header length
+ * @resp_data_len: Response data (SDU or error) length
  */
 struct efx_mcdi_iface {
 	atomic_t state;
@@ -53,7 +54,8 @@ struct efx_mcdi_iface {
 	unsigned int credits;
 	unsigned int seqno;
 	int resprc;
-	size_t resplen;
+	size_t resp_hdr_len;
+	size_t resp_data_len;
 };
 
 struct efx_mcdi_mon {
@@ -93,8 +95,8 @@ extern int efx_mcdi_rpc(struct efx_nic *efx, unsigned cmd,
 			efx_dword_t *outbuf, size_t outlen,
 			size_t *outlen_actual);
 
-extern void efx_mcdi_rpc_start(struct efx_nic *efx, unsigned cmd,
-			       const efx_dword_t *inbuf, size_t inlen);
+extern int efx_mcdi_rpc_start(struct efx_nic *efx, unsigned cmd,
+			      const efx_dword_t *inbuf, size_t inlen);
 extern int efx_mcdi_rpc_finish(struct efx_nic *efx, unsigned cmd, size_t inlen,
 			       efx_dword_t *outbuf, size_t outlen,
 			       size_t *outlen_actual);
diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 7283cc1..e1deec4 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -1029,6 +1029,7 @@ static inline unsigned int efx_port_num(struct efx_nic *efx)
  * @timer_period_max: Maximum period of interrupt timer (in ticks)
  * @offload_features: net_device feature flags for protocol offload
  *	features implemented in hardware
+ * @mcdi_max_ver: Maximum MCDI version supported
  */
 struct efx_nic_type {
 	int (*probe)(struct efx_nic *efx);
@@ -1105,6 +1106,7 @@ struct efx_nic_type {
 	unsigned int phys_addr_channels;
 	unsigned int timer_period_max;
 	netdev_features_t offload_features;
+	int mcdi_max_ver;
 };
 
 /**************************************************************************
diff --git a/drivers/net/ethernet/sfc/ptp.c b/drivers/net/ethernet/sfc/ptp.c
index 59e09e1..b386901 100644
--- a/drivers/net/ethernet/sfc/ptp.c
+++ b/drivers/net/ethernet/sfc/ptp.c
@@ -538,8 +538,9 @@ static int efx_ptp_synchronize(struct efx_nic *efx, unsigned int num_readings)
 
 	/* Clear flag that signals MC ready */
 	ACCESS_ONCE(*start) = 0;
-	efx_mcdi_rpc_start(efx, MC_CMD_PTP, synch_buf,
-			   MC_CMD_PTP_IN_SYNCHRONIZE_LEN);
+	rc = efx_mcdi_rpc_start(efx, MC_CMD_PTP, synch_buf,
+				MC_CMD_PTP_IN_SYNCHRONIZE_LEN);
+	EFX_BUG_ON_PARANOID(rc);
 
 	/* Wait for start from MCDI (or timeout) */
 	timeout = jiffies + msecs_to_jiffies(MAX_SYNCHRONISE_WAIT_MS);
diff --git a/drivers/net/ethernet/sfc/siena.c b/drivers/net/ethernet/sfc/siena.c
index 6a833d5..fee0d2d 100644
--- a/drivers/net/ethernet/sfc/siena.c
+++ b/drivers/net/ethernet/sfc/siena.c
@@ -747,4 +747,5 @@ const struct efx_nic_type siena_a0_nic_type = {
 	.timer_period_max = 1 << FRF_CZ_TC_TIMER_VAL_WIDTH,
 	.offload_features = (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
 			     NETIF_F_RXHASH | NETIF_F_NTUPLE),
+	.mcdi_max_ver = 1,
 };