nfp: fix absolute rtsym handling in debug dump

In TLV-based ethtool debug dumps, don't do a CPP read for absolute
rtsyms, use the addr field in the symbol table directly as the value.

Without this fix rtsym gro_release_ring_0 is 4 bytes of zeros.
With this fix the correct value, 0x0000004a 0x00000000 is reported.

The values may be read using ethtool debug level 2.
 # ethtool -W <netdev> 2
 # ethtool -w <netdev> data dump.dat

Fixes: e1e798e3 ("nfp: dump rtsyms")
Signed-off-by: Carl Heymann <carl.heymann@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Simon Horman <simon.horman@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -265,6 +265,7 @@ nfp_calc_rtsym_dump_sz(struct nfp_pf *pf, struct nfp_dump_tl *spec)
 	struct nfp_dumpspec_rtsym *spec_rtsym;
 	const struct nfp_rtsym *sym;
 	u32 tl_len, key_len;
+	u32 size;
 
 	spec_rtsym = (struct nfp_dumpspec_rtsym *)spec;
 	tl_len = be32_to_cpu(spec->length);
@@ -276,8 +277,13 @@ nfp_calc_rtsym_dump_sz(struct nfp_pf *pf, struct nfp_dump_tl *spec)
 	if (!sym)
 		return nfp_dump_error_tlv_size(spec);
 
+	if (sym->type == NFP_RTSYM_TYPE_ABS)
+		size = sizeof(sym->addr);
+	else
+		size = sym->size;
+
 	return ALIGN8(offsetof(struct nfp_dump_rtsym, rtsym) + key_len + 1) +
-	       ALIGN8(sym->size);
+	       ALIGN8(size);
 }
 
 static int
@@ -654,21 +660,25 @@ nfp_dump_single_rtsym(struct nfp_pf *pf, struct nfp_dumpspec_rtsym *spec,
 		header_size - offsetof(struct nfp_dump_rtsym, rtsym);
 	memcpy(dump_header->rtsym, spec->rtsym, key_len + 1);
 
-	cpp_params.target = sym->target;
-	cpp_params.action = NFP_CPP_ACTION_RW;
-	cpp_params.token  = 0;
-	cpp_params.island = sym->domain;
-	cpp_id = nfp_get_numeric_cpp_id(&cpp_params);
-
-	dump_header->cpp.cpp_id = cpp_params;
-	dump_header->cpp.offset = cpu_to_be32(sym->addr);
-	dump_header->cpp.dump_length = cpu_to_be32(sym->size);
-
-	bytes_read = nfp_cpp_read(pf->cpp, cpp_id, sym->addr, dest, sym->size);
-	if (bytes_read != sym->size) {
-		if (bytes_read >= 0)
-			bytes_read = -EIO;
-		dump_header->error = cpu_to_be32(bytes_read);
+	if (sym->type == NFP_RTSYM_TYPE_ABS) {
+		dump_header->cpp.dump_length = cpu_to_be32(sizeof(sym->addr));
+		*(u64 *)dest = sym->addr;
+	} else {
+		cpp_params.target = sym->target;
+		cpp_params.action = NFP_CPP_ACTION_RW;
+		cpp_params.token  = 0;
+		cpp_params.island = sym->domain;
+		cpp_id = nfp_get_numeric_cpp_id(&cpp_params);
+		dump_header->cpp.cpp_id = cpp_params;
+		dump_header->cpp.offset = cpu_to_be32(sym->addr);
+		dump_header->cpp.dump_length = cpu_to_be32(sym->size);
+		bytes_read = nfp_cpp_read(pf->cpp, cpp_id, sym->addr, dest,
+					  sym->size);
+		if (bytes_read != sym->size) {
+			if (bytes_read >= 0)
+				bytes_read = -EIO;
+			dump_header->error = cpu_to_be32(bytes_read);
+		}
 	}
 
 	return 0;