nfp: abm: add helpers for configuring queue marking levels

Queue levels for simple ECN marking are stored in _abi_nfd_out_q_lvls_X
symbol, where X is the PCIe PF id.  Find out the location of that symbol
and add helpers for modifying it.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/abm/ctrl.c

@@ -35,12 +35,57 @@
 #include <linux/kernel.h>
 
 #include "../nfpcore/nfp_cpp.h"
+#include "../nfpcore/nfp_nffw.h"
 #include "../nfp_app.h"
 #include "../nfp_abi.h"
 #include "../nfp_main.h"
 #include "../nfp_net.h"
 #include "main.h"
 
+#define NFP_QLVL_SYM_NAME	"_abi_nfd_out_q_lvls_%u"
+#define NFP_QLVL_STRIDE		16
+#define NFP_QLVL_THRS		8
+
+static unsigned long long
+nfp_abm_q_lvl_thrs(struct nfp_abm_link *alink, unsigned int queue)
+{
+	return alink->abm->q_lvls->addr +
+		(alink->queue_base + queue) * NFP_QLVL_STRIDE + NFP_QLVL_THRS;
+}
+
+static int
+nfp_abm_ctrl_set_q_lvl(struct nfp_abm_link *alink, unsigned int i, u32 val)
+{
+	struct nfp_cpp *cpp = alink->abm->app->cpp;
+	u32 muw;
+	int err;
+
+	muw = NFP_CPP_ATOMIC_WR(alink->abm->q_lvls->target,
+				alink->abm->q_lvls->domain);
+
+	err = nfp_cpp_writel(cpp, muw, nfp_abm_q_lvl_thrs(alink, i), val);
+	if (err) {
+		nfp_err(cpp, "RED offload setting level failed on vNIC %d queue %d\n",
+			alink->id, i);
+		return err;
+	}
+
+	return 0;
+}
+
+int nfp_abm_ctrl_set_all_q_lvls(struct nfp_abm_link *alink, u32 val)
+{
+	int i, err;
+
+	for (i = 0; i < alink->vnic->max_rx_rings; i++) {
+		err = nfp_abm_ctrl_set_q_lvl(alink, i, val);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
 int nfp_abm_ctrl_qm_enable(struct nfp_abm *abm)
 {
 	return nfp_mbox_cmd(abm->app->pf, NFP_MBOX_PCIE_ABM_ENABLE,
@@ -59,13 +104,48 @@ void nfp_abm_ctrl_read_params(struct nfp_abm_link *alink)
 	alink->queue_base /= alink->vnic->stride_rx;
 }
 
+static const struct nfp_rtsym *
+nfp_abm_ctrl_find_rtsym(struct nfp_pf *pf, const char *name, unsigned int size)
+{
+	const struct nfp_rtsym *sym;
+
+	sym = nfp_rtsym_lookup(pf->rtbl, name);
+	if (!sym) {
+		nfp_err(pf->cpp, "Symbol '%s' not found\n", name);
+		return ERR_PTR(-ENOENT);
+	}
+	if (sym->size != size) {
+		nfp_err(pf->cpp,
+			"Symbol '%s' wrong size: expected %u got %llu\n",
+			name, size, sym->size);
+		return ERR_PTR(-EINVAL);
+	}
+
+	return sym;
+}
+
+static const struct nfp_rtsym *
+nfp_abm_ctrl_find_q_rtsym(struct nfp_pf *pf, const char *name,
+			  unsigned int size)
+{
+	return nfp_abm_ctrl_find_rtsym(pf, name, size * NFP_NET_MAX_RX_RINGS);
+}
+
 int nfp_abm_ctrl_find_addrs(struct nfp_abm *abm)
 {
 	struct nfp_pf *pf = abm->app->pf;
+	const struct nfp_rtsym *sym;
 	unsigned int pf_id;
+	char pf_symbol[64];
 
 	pf_id =	nfp_cppcore_pcie_unit(pf->cpp);
 	abm->pf_id = pf_id;
 
+	snprintf(pf_symbol, sizeof(pf_symbol), NFP_QLVL_SYM_NAME, pf_id);
+	sym = nfp_abm_ctrl_find_q_rtsym(pf, pf_symbol, NFP_QLVL_STRIDE);
+	if (IS_ERR(sym))
+		return PTR_ERR(sym);
+	abm->q_lvls = sym;
+
 	return 0;
 }

drivers/net/ethernet/netronome/nfp/abm/main.h

@@ -49,11 +49,13 @@ struct nfp_net;
  * @pf_id:	ID of our PF link
  * @eswitch_mode:	devlink eswitch mode, advanced functions only visible
  *			in switchdev mode
+ * @q_lvls:	queue level control area
  */
 struct nfp_abm {
 	struct nfp_app *app;
 	unsigned int pf_id;
 	enum devlink_eswitch_mode eswitch_mode;
+	const struct nfp_rtsym *q_lvls;
 };
 
 /**
@@ -72,6 +74,7 @@ struct nfp_abm_link {
 
 void nfp_abm_ctrl_read_params(struct nfp_abm_link *alink);
 int nfp_abm_ctrl_find_addrs(struct nfp_abm *abm);
+int nfp_abm_ctrl_set_all_q_lvls(struct nfp_abm_link *alink, u32 val);
 int nfp_abm_ctrl_qm_enable(struct nfp_abm *abm);
 int nfp_abm_ctrl_qm_disable(struct nfp_abm *abm);
 #endif

drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cpp.h

@@ -87,6 +87,11 @@ struct resource;
 
 #define NFP_CPP_TARGET_ID_MASK          0x1f
 
+#define NFP_CPP_ATOMIC_RD(target, island) \
+	NFP_CPP_ISLAND_ID((target), 3, 0, (island))
+#define NFP_CPP_ATOMIC_WR(target, island) \
+	NFP_CPP_ISLAND_ID((target), 4, 0, (island))
+
 /**
  * NFP_CPP_ID() - pack target, token, and action into a CPP ID.
  * @target:     NFP CPP target id