octeontx2-af: Interface backpressure configuration

Each of the interface receive channels can be backpressured by
resources upon exhaustion or reaching configured threshold levels.
Resources here are receive buffer queues (Auras) and pkt notification
descriptor queues (CQs). Resources and interface channels are mapped
using backpressure IDs (BPIDs).

HW supports upto 512 BPIDs, this patch divides these BPIDs statically
across CGX/LBK/SDP interfaces as follows.
BPIDs 0 - 191 are mapped to LMAC channels, 16 per LMAC.
BPIDs 192 - 255 are mapped to LBK channels.
BPIDs 256 - 511 are mapped to SDP channels.
Also did the needed basic configuration of BPIDs.

Added mbox handlers with which a PF device can request for a BPID which
it will use to configure Auras and CQs.

Signed-off-by: Geetha sowjanya <gakula@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/octeontx2/af/mbox.h

@@ -125,7 +125,7 @@ static inline struct mbox_msghdr *otx2_mbox_alloc_msg(struct otx2_mbox *mbox,
 M(READY,		0x001, ready, msg_req, ready_msg_rsp)		\
 M(ATTACH_RESOURCES,	0x002, attach_resources, rsrc_attach, msg_rsp)	\
 M(DETACH_RESOURCES,	0x003, detach_resources, rsrc_detach, msg_rsp)	\
-M(MSIX_OFFSET,		0x004, msix_offset, msg_req, msix_offset_rsp)	\
+M(MSIX_OFFSET,		0x005, msix_offset, msg_req, msix_offset_rsp)	\
 M(VF_FLR,		0x006, vf_flr, msg_req, msg_rsp)		\
 M(GET_HW_CAP,		0x008, get_hw_cap, msg_req, get_hw_cap_rsp)	\
 /* CGX mbox IDs (range 0x200 - 0x3FF) */				\
@@ -211,6 +211,9 @@ M(NIX_LSO_FORMAT_CFG,	0x8011, nix_lso_format_cfg,			\
 				 nix_lso_format_cfg,			\
 				 nix_lso_format_cfg_rsp)		\
 M(NIX_RXVLAN_ALLOC,	0x8012, nix_rxvlan_alloc, msg_req, msg_rsp)	\
+M(NIX_BP_ENABLE,	0x8016, nix_bp_enable, nix_bp_cfg_req,	\
+				nix_bp_cfg_rsp)	\
+M(NIX_BP_DISABLE,	0x8017, nix_bp_disable, nix_bp_cfg_req, msg_rsp) \
 M(NIX_GET_MAC_ADDR, 0x8018, nix_get_mac_addr, msg_req, nix_get_mac_addr_rsp) \
 
 /* Messages initiated by AF (range 0xC00 - 0xDFF) */
@@ -676,6 +679,25 @@ struct nix_lso_format_cfg_rsp {
 	u8 lso_format_idx;
 };
 
+struct nix_bp_cfg_req {
+	struct mbox_msghdr hdr;
+	u16	chan_base; /* Starting channel number */
+	u8	chan_cnt; /* Number of channels */
+	u8	bpid_per_chan;
+	/* bpid_per_chan = 0 assigns single bp id for range of channels */
+	/* bpid_per_chan = 1 assigns separate bp id for each channel */
+};
+
+/* PF can be mapped to either CGX or LBK interface,
+ * so maximum 64 channels are possible.
+ */
+#define NIX_MAX_BPID_CHAN	64
+struct nix_bp_cfg_rsp {
+	struct mbox_msghdr hdr;
+	u16	chan_bpid[NIX_MAX_BPID_CHAN]; /* Channel and bpid mapping */
+	u8	chan_cnt; /* Number of channel for which bpids are assigned */
+};
+
 /* NPC mbox message structs */
 
 #define NPC_MCAM_ENTRY_INVALID	0xFFFF

drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c

@@ -18,6 +18,8 @@
 #include "cgx.h"
 
 static int nix_update_bcast_mce_list(struct rvu *rvu, u16 pcifunc, bool add);
+static int rvu_nix_get_bpid(struct rvu *rvu, struct nix_bp_cfg_req *req,
+			    int type, int chan_id);
 
 enum mc_tbl_sz {
 	MC_TBL_SZ_256,
@@ -273,6 +275,142 @@ static void nix_interface_deinit(struct rvu *rvu, u16 pcifunc, u8 nixlf)
 	rvu_npc_disable_mcam_entries(rvu, pcifunc, nixlf);
 }
 
+int rvu_mbox_handler_nix_bp_disable(struct rvu *rvu,
+				    struct nix_bp_cfg_req *req,
+				    struct msg_rsp *rsp)
+{
+	u16 pcifunc = req->hdr.pcifunc;
+	struct rvu_pfvf *pfvf;
+	int blkaddr, pf, type;
+	u16 chan_base, chan;
+	u64 cfg;
+
+	pf = rvu_get_pf(pcifunc);
+	type = is_afvf(pcifunc) ? NIX_INTF_TYPE_LBK : NIX_INTF_TYPE_CGX;
+	if (!is_pf_cgxmapped(rvu, pf) && type != NIX_INTF_TYPE_LBK)
+		return 0;
+
+	pfvf = rvu_get_pfvf(rvu, pcifunc);
+	blkaddr = rvu_get_blkaddr(rvu, BLKTYPE_NIX, pcifunc);
+
+	chan_base = pfvf->rx_chan_base + req->chan_base;
+	for (chan = chan_base; chan < (chan_base + req->chan_cnt); chan++) {
+		cfg = rvu_read64(rvu, blkaddr, NIX_AF_RX_CHANX_CFG(chan));
+		rvu_write64(rvu, blkaddr, NIX_AF_RX_CHANX_CFG(chan),
+			    cfg & ~BIT_ULL(16));
+	}
+	return 0;
+}
+
+static int rvu_nix_get_bpid(struct rvu *rvu, struct nix_bp_cfg_req *req,
+			    int type, int chan_id)
+{
+	int bpid, blkaddr, lmac_chan_cnt;
+	struct rvu_hwinfo *hw = rvu->hw;
+	u16 cgx_bpid_cnt, lbk_bpid_cnt;
+	struct rvu_pfvf *pfvf;
+	u8 cgx_id, lmac_id;
+	u64 cfg;
+
+	blkaddr = rvu_get_blkaddr(rvu, BLKTYPE_NIX, req->hdr.pcifunc);
+	cfg = rvu_read64(rvu, blkaddr, NIX_AF_CONST);
+	lmac_chan_cnt = cfg & 0xFF;
+
+	cgx_bpid_cnt = hw->cgx_links * lmac_chan_cnt;
+	lbk_bpid_cnt = hw->lbk_links * ((cfg >> 16) & 0xFF);
+
+	pfvf = rvu_get_pfvf(rvu, req->hdr.pcifunc);
+
+	/* Backpressure IDs range division
+	 * CGX channles are mapped to (0 - 191) BPIDs
+	 * LBK channles are mapped to (192 - 255) BPIDs
+	 * SDP channles are mapped to (256 - 511) BPIDs
+	 *
+	 * Lmac channles and bpids mapped as follows
+	 * cgx(0)_lmac(0)_chan(0 - 15) = bpid(0 - 15)
+	 * cgx(0)_lmac(1)_chan(0 - 15) = bpid(16 - 31) ....
+	 * cgx(1)_lmac(0)_chan(0 - 15) = bpid(64 - 79) ....
+	 */
+	switch (type) {
+	case NIX_INTF_TYPE_CGX:
+		if ((req->chan_base + req->chan_cnt) > 15)
+			return -EINVAL;
+		rvu_get_cgx_lmac_id(pfvf->cgx_lmac, &cgx_id, &lmac_id);
+		/* Assign bpid based on cgx, lmac and chan id */
+		bpid = (cgx_id * hw->lmac_per_cgx * lmac_chan_cnt) +
+			(lmac_id * lmac_chan_cnt) + req->chan_base;
+
+		if (req->bpid_per_chan)
+			bpid += chan_id;
+		if (bpid > cgx_bpid_cnt)
+			return -EINVAL;
+		break;
+
+	case NIX_INTF_TYPE_LBK:
+		if ((req->chan_base + req->chan_cnt) > 63)
+			return -EINVAL;
+		bpid = cgx_bpid_cnt + req->chan_base;
+		if (req->bpid_per_chan)
+			bpid += chan_id;
+		if (bpid > (cgx_bpid_cnt + lbk_bpid_cnt))
+			return -EINVAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+	return bpid;
+}
+
+int rvu_mbox_handler_nix_bp_enable(struct rvu *rvu,
+				   struct nix_bp_cfg_req *req,
+				   struct nix_bp_cfg_rsp *rsp)
+{
+	int blkaddr, pf, type, chan_id = 0;
+	u16 pcifunc = req->hdr.pcifunc;
+	struct rvu_pfvf *pfvf;
+	u16 chan_base, chan;
+	s16 bpid, bpid_base;
+	u64 cfg;
+
+	pf = rvu_get_pf(pcifunc);
+	type = is_afvf(pcifunc) ? NIX_INTF_TYPE_LBK : NIX_INTF_TYPE_CGX;
+
+	/* Enable backpressure only for CGX mapped PFs and LBK interface */
+	if (!is_pf_cgxmapped(rvu, pf) && type != NIX_INTF_TYPE_LBK)
+		return 0;
+
+	pfvf = rvu_get_pfvf(rvu, pcifunc);
+	blkaddr = rvu_get_blkaddr(rvu, BLKTYPE_NIX, pcifunc);
+
+	bpid_base = rvu_nix_get_bpid(rvu, req, type, chan_id);
+	chan_base = pfvf->rx_chan_base + req->chan_base;
+	bpid = bpid_base;
+
+	for (chan = chan_base; chan < (chan_base + req->chan_cnt); chan++) {
+		if (bpid < 0) {
+			dev_warn(rvu->dev, "Fail to enable backpessure\n");
+			return -EINVAL;
+		}
+
+		cfg = rvu_read64(rvu, blkaddr, NIX_AF_RX_CHANX_CFG(chan));
+		rvu_write64(rvu, blkaddr, NIX_AF_RX_CHANX_CFG(chan),
+			    cfg | (bpid & 0xFF) | BIT_ULL(16));
+		chan_id++;
+		bpid = rvu_nix_get_bpid(rvu, req, type, chan_id);
+	}
+
+	for (chan = 0; chan < req->chan_cnt; chan++) {
+		/* Map channel and bpid assign to it */
+		rsp->chan_bpid[chan] = ((req->chan_base + chan) & 0x7F) << 10 |
+					(bpid_base & 0x3FF);
+		if (req->bpid_per_chan)
+			bpid_base++;
+	}
+	rsp->chan_cnt = req->chan_cnt;
+
+	return 0;
+}
+
 static void nix_setup_lso_tso_l3(struct rvu *rvu, int blkaddr,
 				 u64 format, bool v4, u64 *fidx)
 {
@@ -565,6 +703,11 @@ static int rvu_nix_aq_enq_inst(struct rvu *rvu, struct nix_aq_enq_req *req,
 	 */
 	inst.res_addr = (u64)aq->res->iova;
 
+	/* Hardware uses same aq->res->base for updating result of
+	 * previous instruction hence wait here till it is done.
+	 */
+	spin_lock(&aq->lock);
+
 	/* Clean result + context memory */
 	memset(aq->res->base, 0, aq->res->entry_sz);
 	/* Context needs to be written at RES_ADDR + 128 */
@@ -609,11 +752,10 @@ static int rvu_nix_aq_enq_inst(struct rvu *rvu, struct nix_aq_enq_req *req,
 		break;
 	default:
 		rc = NIX_AF_ERR_AQ_ENQUEUE;
+		spin_unlock(&aq->lock);
 		return rc;
 	}
 
-	spin_lock(&aq->lock);
-
 	/* Submit the instruction to AQ */
 	rc = nix_aq_enqueue_wait(rvu, block, &inst);
 	if (rc) {
@@ -718,6 +860,8 @@ static int nix_lf_hwctx_disable(struct rvu *rvu, struct hwctx_disable_req *req)
 	if (req->ctype == NIX_AQ_CTYPE_CQ) {
 		aq_req.cq.ena = 0;
 		aq_req.cq_mask.ena = 1;
+		aq_req.cq.bp_ena = 0;
+		aq_req.cq_mask.bp_ena = 1;
 		q_cnt = pfvf->cq_ctx->qsize;
 		bmap = pfvf->cq_bmap;
 	}
@@ -3061,6 +3205,9 @@ int rvu_nix_init(struct rvu *rvu)
 
 		/* Initialize CGX/LBK/SDP link credits, min/max pkt lengths */
 		nix_link_config(rvu, blkaddr);
+
+		/* Enable Channel backpressure */
+		rvu_write64(rvu, blkaddr, NIX_AF_RX_CFG, BIT_ULL(0));
 	}
 	return 0;
 }

drivers/net/ethernet/marvell/octeontx2/af/rvu_npa.c

@@ -94,6 +94,11 @@ int rvu_npa_aq_enq_inst(struct rvu *rvu, struct npa_aq_enq_req *req,
 	 */
 	inst.res_addr = (u64)aq->res->iova;
 
+	/* Hardware uses same aq->res->base for updating result of
+	 * previous instruction hence wait here till it is done.
+	 */
+	spin_lock(&aq->lock);
+
 	/* Clean result + context memory */
 	memset(aq->res->base, 0, aq->res->entry_sz);
 	/* Context needs to be written at RES_ADDR + 128 */
@@ -138,10 +143,10 @@ int rvu_npa_aq_enq_inst(struct rvu *rvu, struct npa_aq_enq_req *req,
 		break;
 	}
 
-	if (rc)
+	if (rc) {
+		spin_unlock(&aq->lock);
 		return rc;
-
-	spin_lock(&aq->lock);
+	}
 
 	/* Submit the instruction to AQ */
 	rc = npa_aq_enqueue_wait(rvu, block, &inst);
@@ -218,6 +223,8 @@ static int npa_lf_hwctx_disable(struct rvu *rvu, struct hwctx_disable_req *req)
 	} else if (req->ctype == NPA_AQ_CTYPE_AURA) {
 		aq_req.aura.ena = 0;
 		aq_req.aura_mask.ena = 1;
+		aq_req.aura.bp_ena = 0;
+		aq_req.aura_mask.bp_ena = 1;
 		cnt = pfvf->aura_ctx->qsize;
 		bmap = pfvf->aura_bmap;
 	}