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>

1 files changed, 113 insertions, 49 deletions

diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index c6c5830996cf..2c5ee893feeb 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 {