sfc: Add use of shared RSS contexts.

Allow PFs to allocate shared RSS contexts if we exhaust our
exclusive RSS contexts. Make VFs use shared RSS contexts in
all cases.
Spruce up error handling so that the shadow copy of the RSS
table is updated after successful update, rather than in all
cases, so that we report the actual contents of the RSS table
after a failure to set it, rather than what we'd like it to be.

Populate context_size parameter when vacuously allocating RSS
context of size 1.

Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 135 insertions, 22 deletions

diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
index ae0ed2aa6eca..7a67202fb1cb 100644
--- a/drivers/net/ethernet/sfc/ef10.c
+++ b/drivers/net/ethernet/sfc/ef10.c
@@ -31,6 +31,9 @@ enum {
 
 /* The reserved RSS context value */
 #define EFX_EF10_RSS_CONTEXT_INVALID	0xffffffff
+/* The maximum size of a shared RSS context */
+/* TODO: this should really be from the mcdi protocol export */
+#define EFX_EF10_MAX_SHARED_RSS_CONTEXT_SIZE 64UL
 
 /* The filter table(s) are managed by firmware and we have write-only
  * access.  When removing filters we must identify them to the
@@ -78,7 +81,6 @@ struct efx_ef10_filter_table {
 /* An arbitrary search limit for the software hash table */
 #define EFX_EF10_FILTER_SEARCH_LIMIT 200
 
-static void efx_ef10_rx_push_rss_config(struct efx_nic *efx);
 static void efx_ef10_rx_free_indir_table(struct efx_nic *efx);
 static void efx_ef10_filter_table_remove(struct efx_nic *efx);
 
@@ -751,7 +753,9 @@ static int efx_ef10_init_nic(struct efx_nic *efx)
 		nic_data->must_restore_piobufs = false;
 	}
 
-	efx_ef10_rx_push_rss_config(efx);
+	/* don't fail init if RSS setup doesn't work */
+	efx->type->rx_push_rss_config(efx, false, efx->rx_indir_table);
+
 	return 0;
 }
 
@@ -1455,20 +1459,33 @@ static void efx_ef10_tx_write(struct efx_tx_queue *tx_queue)
 	}
 }
 
-static int efx_ef10_alloc_rss_context(struct efx_nic *efx, u32 *context)
+static int efx_ef10_alloc_rss_context(struct efx_nic *efx, u32 *context,
+				      bool exclusive, unsigned *context_size)
 {
 	MCDI_DECLARE_BUF(inbuf, MC_CMD_RSS_CONTEXT_ALLOC_IN_LEN);
 	MCDI_DECLARE_BUF(outbuf, MC_CMD_RSS_CONTEXT_ALLOC_OUT_LEN);
 	struct efx_ef10_nic_data *nic_data = efx->nic_data;
 	size_t outlen;
 	int rc;
+	u32 alloc_type = exclusive ?
+				MC_CMD_RSS_CONTEXT_ALLOC_IN_TYPE_EXCLUSIVE :
+				MC_CMD_RSS_CONTEXT_ALLOC_IN_TYPE_SHARED;
+	unsigned rss_spread = exclusive ?
+				efx->rss_spread :
+				min(rounddown_pow_of_two(efx->rss_spread),
+				    EFX_EF10_MAX_SHARED_RSS_CONTEXT_SIZE);
+
+	if (!exclusive && rss_spread == 1) {
+		*context = EFX_EF10_RSS_CONTEXT_INVALID;
+		if (context_size)
+			*context_size = 1;
+		return 0;
+	}
 
 	MCDI_SET_DWORD(inbuf, RSS_CONTEXT_ALLOC_IN_UPSTREAM_PORT_ID,
 		       nic_data->vport_id);
-	MCDI_SET_DWORD(inbuf, RSS_CONTEXT_ALLOC_IN_TYPE,
-		       MC_CMD_RSS_CONTEXT_ALLOC_IN_TYPE_EXCLUSIVE);
-	MCDI_SET_DWORD(inbuf, RSS_CONTEXT_ALLOC_IN_NUM_QUEUES,
-		       EFX_MAX_CHANNELS);
+	MCDI_SET_DWORD(inbuf, RSS_CONTEXT_ALLOC_IN_TYPE, alloc_type);
+	MCDI_SET_DWORD(inbuf, RSS_CONTEXT_ALLOC_IN_NUM_QUEUES, rss_spread);
 
 	rc = efx_mcdi_rpc(efx, MC_CMD_RSS_CONTEXT_ALLOC, inbuf, sizeof(inbuf),
 		outbuf, sizeof(outbuf), &outlen);
@@ -1480,6 +1497,9 @@ static int efx_ef10_alloc_rss_context(struct efx_nic *efx, u32 *context)
 
 	*context = MCDI_DWORD(outbuf, RSS_CONTEXT_ALLOC_OUT_RSS_CONTEXT_ID);
 
+	if (context_size)
+		*context_size = rss_spread;
+
 	return 0;
 }
 
@@ -1496,7 +1516,8 @@ static void efx_ef10_free_rss_context(struct efx_nic *efx, u32 context)
 	WARN_ON(rc != 0);
 }
 
-static int efx_ef10_populate_rss_table(struct efx_nic *efx, u32 context)
+static int efx_ef10_populate_rss_table(struct efx_nic *efx, u32 context,
+				       const u32 *rx_indir_table)
 {
 	MCDI_DECLARE_BUF(tablebuf, MC_CMD_RSS_CONTEXT_SET_TABLE_IN_LEN);
 	MCDI_DECLARE_BUF(keybuf, MC_CMD_RSS_CONTEXT_SET_KEY_IN_LEN);
@@ -1510,7 +1531,7 @@ static int efx_ef10_populate_rss_table(struct efx_nic *efx, u32 context)
 	for (i = 0; i < ARRAY_SIZE(efx->rx_indir_table); ++i)
 		MCDI_PTR(tablebuf,
 			 RSS_CONTEXT_SET_TABLE_IN_INDIRECTION_TABLE)[i] =
-				(u8) efx->rx_indir_table[i];
+				(u8) rx_indir_table[i];
 
 	rc = efx_mcdi_rpc(efx, MC_CMD_RSS_CONTEXT_SET_TABLE, tablebuf,
 			  sizeof(tablebuf), NULL, 0, NULL);
@@ -1538,27 +1559,119 @@ static void efx_ef10_rx_free_indir_table(struct efx_nic *efx)
 	nic_data->rx_rss_context = EFX_EF10_RSS_CONTEXT_INVALID;
 }
 
-static void efx_ef10_rx_push_rss_config(struct efx_nic *efx)
+static int efx_ef10_rx_push_shared_rss_config(struct efx_nic *efx,
+					      unsigned *context_size)
 {
+	u32 new_rx_rss_context;
 	struct efx_ef10_nic_data *nic_data = efx->nic_data;
-	int rc;
+	int rc = efx_ef10_alloc_rss_context(efx, &new_rx_rss_context,
+					    false, context_size);
+
+	if (rc != 0)
+		return rc;
 
-	netif_dbg(efx, drv, efx->net_dev, "pushing RSS config\n");
+	nic_data->rx_rss_context = new_rx_rss_context;
+	nic_data->rx_rss_context_exclusive = false;
+	efx_set_default_rx_indir_table(efx);
+	return 0;
+}
 
-	if (nic_data->rx_rss_context == EFX_EF10_RSS_CONTEXT_INVALID) {
-		rc = efx_ef10_alloc_rss_context(efx, &nic_data->rx_rss_context);
-		if (rc != 0)
-			goto fail;
+static int efx_ef10_rx_push_exclusive_rss_config(struct efx_nic *efx,
+						 const u32 *rx_indir_table)
+{
+	struct efx_ef10_nic_data *nic_data = efx->nic_data;
+	int rc;
+	u32 new_rx_rss_context;
+
+	if (nic_data->rx_rss_context == EFX_EF10_RSS_CONTEXT_INVALID ||
+	    !nic_data->rx_rss_context_exclusive) {
+		rc = efx_ef10_alloc_rss_context(efx, &new_rx_rss_context,
+						true, NULL);
+		if (rc == -EOPNOTSUPP)
+			return rc;
+		else if (rc != 0)
+			goto fail1;
+	} else {
+		new_rx_rss_context = nic_data->rx_rss_context;
 	}
 
-	rc = efx_ef10_populate_rss_table(efx, nic_data->rx_rss_context);
+	rc = efx_ef10_populate_rss_table(efx, new_rx_rss_context,
+					 rx_indir_table);
 	if (rc != 0)
-		goto fail;
+		goto fail2;
 
-	return;
+	if (nic_data->rx_rss_context != new_rx_rss_context)
+		efx_ef10_rx_free_indir_table(efx);
+	nic_data->rx_rss_context = new_rx_rss_context;
+	nic_data->rx_rss_context_exclusive = true;
+	if (rx_indir_table != efx->rx_indir_table)
+		memcpy(efx->rx_indir_table, rx_indir_table,
+		       sizeof(efx->rx_indir_table));
+	return 0;
 
-fail:
+fail2:
+	if (new_rx_rss_context != nic_data->rx_rss_context)
+		efx_ef10_free_rss_context(efx, new_rx_rss_context);
+fail1:
 	netif_err(efx, hw, efx->net_dev, "%s: failed rc=%d\n", __func__, rc);
+	return rc;
+}
+
+static int efx_ef10_pf_rx_push_rss_config(struct efx_nic *efx, bool user,
+					  const u32 *rx_indir_table)
+{
+	int rc;
+
+	if (efx->rss_spread == 1)
+		return 0;
+
+	rc = efx_ef10_rx_push_exclusive_rss_config(efx, rx_indir_table);
+
+	if (rc == -ENOBUFS && !user) {
+		unsigned context_size;
+		bool mismatch = false;
+		size_t i;
+
+		for (i = 0; i < ARRAY_SIZE(efx->rx_indir_table) && !mismatch;
+		     i++)
+			mismatch = rx_indir_table[i] !=
+				ethtool_rxfh_indir_default(i, efx->rss_spread);
+
+		rc = efx_ef10_rx_push_shared_rss_config(efx, &context_size);
+		if (rc == 0) {
+			if (context_size != efx->rss_spread)
+				netif_warn(efx, probe, efx->net_dev,
+					   "Could not allocate an exclusive RSS"
+					   " context; allocated a shared one of"
+					   " different size."
+					   " Wanted %u, got %u.\n",
+					   efx->rss_spread, context_size);
+			else if (mismatch)
+				netif_warn(efx, probe, efx->net_dev,
+					   "Could not allocate an exclusive RSS"
+					   " context; allocated a shared one but"
+					   " could not apply custom"
+					   " indirection.\n");
+			else
+				netif_info(efx, probe, efx->net_dev,
+					   "Could not allocate an exclusive RSS"
+					   " context; allocated a shared one.\n");
+		}
+	}
+	return rc;
+}
+
+static int efx_ef10_vf_rx_push_rss_config(struct efx_nic *efx, bool user,
+					  const u32 *rx_indir_table
+					  __attribute__ ((unused)))
+{
+	struct efx_ef10_nic_data *nic_data = efx->nic_data;
+
+	if (user)
+		return -EOPNOTSUPP;
+	if (nic_data->rx_rss_context != EFX_EF10_RSS_CONTEXT_INVALID)
+		return 0;
+	return efx_ef10_rx_push_shared_rss_config(efx, NULL);
 }
 
 static int efx_ef10_rx_probe(struct efx_rx_queue *rx_queue)
@@ -3738,7 +3851,7 @@ const struct efx_nic_type efx_hunt_a0_vf_nic_type = {
 	.tx_init = efx_ef10_tx_init,
 	.tx_remove = efx_ef10_tx_remove,
 	.tx_write = efx_ef10_tx_write,
-	.rx_push_rss_config = efx_ef10_rx_push_rss_config,
+	.rx_push_rss_config = efx_ef10_vf_rx_push_rss_config,
 	.rx_probe = efx_ef10_rx_probe,
 	.rx_init = efx_ef10_rx_init,
 	.rx_remove = efx_ef10_rx_remove,
@@ -3837,7 +3950,7 @@ const struct efx_nic_type efx_hunt_a0_nic_type = {
 	.tx_init = efx_ef10_tx_init,
 	.tx_remove = efx_ef10_tx_remove,
 	.tx_write = efx_ef10_tx_write,
-	.rx_push_rss_config = efx_ef10_rx_push_rss_config,
+	.rx_push_rss_config = efx_ef10_pf_rx_push_rss_config,
 	.rx_probe = efx_ef10_rx_probe,
 	.rx_init = efx_ef10_rx_init,
 	.rx_remove = efx_ef10_rx_remove,