nfp: add support for sending control messages via mailbox

FW may prefer to handle some communication via a mailbox
or the vNIC may simply not have a control queue (VFs).
Add a way of exchanging ccm-compatible messages via a
mailbox.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/Makefile

@@ -16,6 +16,7 @@ nfp-objs := \
 	    nfpcore/nfp_rtsym.o \
 	    nfpcore/nfp_target.o \
 	    ccm.o \
+	    ccm_mbox.o \
 	    nfp_asm.o \
 	    nfp_app.o \
 	    nfp_app_nic.o \

drivers/net/ethernet/netronome/nfp/ccm.c

@@ -7,9 +7,6 @@
 #include "nfp_app.h"
 #include "nfp_net.h"
 
-#define NFP_CCM_TYPE_REPLY_BIT		7
-#define __NFP_CCM_REPLY(req)		(BIT(NFP_CCM_TYPE_REPLY_BIT) | (req))
-
 #define ccm_warn(app, msg...)	nn_dp_warn(&(app)->ctrl->dp, msg)
 
 #define NFP_CCM_TAG_ALLOC_SPAN	(U16_MAX / 4)

drivers/net/ethernet/netronome/nfp/ccm.h

@@ -9,6 +9,7 @@
 #include <linux/wait.h>
 
 struct nfp_app;
+struct nfp_net;
 
 /* Firmware ABI */
 
@@ -26,10 +27,18 @@ enum nfp_ccm_type {
 
 #define NFP_CCM_ABI_VERSION		1
 
+#define NFP_CCM_TYPE_REPLY_BIT		7
+#define __NFP_CCM_REPLY(req)		(BIT(NFP_CCM_TYPE_REPLY_BIT) | (req))
+
 struct nfp_ccm_hdr {
-	u8 type;
-	u8 ver;
-	__be16 tag;
+	union {
+		struct {
+			u8 type;
+			u8 ver;
+			__be16 tag;
+		};
+		__be32 raw;
+	};
 };
 
 static inline u8 nfp_ccm_get_type(struct sk_buff *skb)
@@ -41,15 +50,31 @@ static inline u8 nfp_ccm_get_type(struct sk_buff *skb)
 	return hdr->type;
 }
 
-static inline unsigned int nfp_ccm_get_tag(struct sk_buff *skb)
+static inline __be16 __nfp_ccm_get_tag(struct sk_buff *skb)
 {
 	struct nfp_ccm_hdr *hdr;
 
 	hdr = (struct nfp_ccm_hdr *)skb->data;
 
-	return be16_to_cpu(hdr->tag);
+	return hdr->tag;
+}
+
+static inline unsigned int nfp_ccm_get_tag(struct sk_buff *skb)
+{
+	return be16_to_cpu(__nfp_ccm_get_tag(skb));
 }
 
+#define NFP_NET_MBOX_TLV_TYPE		GENMASK(31, 16)
+#define NFP_NET_MBOX_TLV_LEN		GENMASK(15, 0)
+
+enum nfp_ccm_mbox_tlv_type {
+	NFP_NET_MBOX_TLV_TYPE_UNKNOWN	= 0,
+	NFP_NET_MBOX_TLV_TYPE_END	= 1,
+	NFP_NET_MBOX_TLV_TYPE_MSG	= 2,
+	NFP_NET_MBOX_TLV_TYPE_MSG_NOSUP	= 3,
+	NFP_NET_MBOX_TLV_TYPE_RESV	= 4,
+};
+
 /* Implementation */
 
 /**
@@ -80,4 +105,13 @@ void nfp_ccm_rx(struct nfp_ccm *ccm, struct sk_buff *skb);
 struct sk_buff *
 nfp_ccm_communicate(struct nfp_ccm *ccm, struct sk_buff *skb,
 		    enum nfp_ccm_type type, unsigned int reply_size);
+
+bool nfp_ccm_mbox_fits(struct nfp_net *nn, unsigned int size);
+struct sk_buff *
+nfp_ccm_mbox_alloc(struct nfp_net *nn, unsigned int req_size,
+		   unsigned int reply_size, gfp_t flags);
+int nfp_ccm_mbox_communicate(struct nfp_net *nn, struct sk_buff *skb,
+			     enum nfp_ccm_type type,
+			     unsigned int reply_size,
+			     unsigned int max_reply_size);
 #endif

drivers/net/ethernet/netronome/nfp/nfp_net.h

@@ -563,6 +563,10 @@ struct nfp_net_dp {
  * @tx_bar:             Pointer to mapped TX queues
  * @rx_bar:             Pointer to mapped FL/RX queues
  * @tlv_caps:		Parsed TLV capabilities
+ * @mbox_cmsg:		Common Control Message via vNIC mailbox state
+ * @mbox_cmsg.queue:	CCM mbox queue of pending messages
+ * @mbox_cmsg.wq:	CCM mbox wait queue of waiting processes
+ * @mbox_cmsg.tag:	CCM mbox message tag allocator
  * @debugfs_dir:	Device directory in debugfs
  * @vnic_list:		Entry on device vNIC list
  * @pdev:		Backpointer to PCI device
@@ -638,6 +642,12 @@ struct nfp_net {
 
 	struct nfp_net_tlv_caps tlv_caps;
 
+	struct {
+		struct sk_buff_head queue;
+		wait_queue_head_t wq;
+		u16 tag;
+	} mbox_cmsg;
+
 	struct dentry *debugfs_dir;
 
 	struct list_head vnic_list;

drivers/net/ethernet/netronome/nfp/nfp_net_common.c

@@ -3705,6 +3705,9 @@ nfp_net_alloc(struct pci_dev *pdev, void __iomem *ctrl_bar, bool needs_netdev,
 
 	timer_setup(&nn->reconfig_timer, nfp_net_reconfig_timer, 0);
 
+	skb_queue_head_init(&nn->mbox_cmsg.queue);
+	init_waitqueue_head(&nn->mbox_cmsg.wq);
+
 	err = nfp_net_tlv_caps_parse(&nn->pdev->dev, nn->dp.ctrl_bar,
 				     &nn->tlv_caps);
 	if (err)
@@ -3727,6 +3730,7 @@ nfp_net_alloc(struct pci_dev *pdev, void __iomem *ctrl_bar, bool needs_netdev,
 void nfp_net_free(struct nfp_net *nn)
 {
 	WARN_ON(timer_pending(&nn->reconfig_timer) || nn->reconfig_posted);
+	WARN_ON(!skb_queue_empty(&nn->mbox_cmsg.queue));
 
 	if (nn->dp.netdev)
 		free_netdev(nn->dp.netdev);

drivers/net/ethernet/netronome/nfp/nfp_net_ctrl.h

@@ -394,6 +394,7 @@
 #define NFP_NET_CFG_MBOX_CMD_CTAG_FILTER_KILL 2
 
 #define NFP_NET_CFG_MBOX_CMD_PCI_DSCP_PRIOMAP_SET	5
+#define NFP_NET_CFG_MBOX_CMD_TLV_CMSG			6
 
 /**
  * VLAN filtering using general use mailbox