of: address: Consolidate bus .map() functions

The bus .map() functions vary only by checking the flag cells values
and skipping over any flag cells to read the addresses. Otherwise they
all do the same reading 'ranges' address and size and returning the
address's offset if it is within the 'ranges' entry.

Refactor all the .map() functions to pass in the flag cell size so that
each bus can check the bus specific flags and then call a common
function to do everything else.

Acked-by: Herve Codina <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Rob Herring <[e-mail]>

drivers/of/address.c

···
 	void		(*count_cells)(struct device_node *child,
 				       int *addrc, int *sizec);
 	u64		(*map)(__be32 *addr, const __be32 *range,
-				int na, int ns, int pna);
+				int na, int ns, int pna, int fna);
 	int		(*translate)(__be32 *addr, u64 offset, int na);
 	int		flag_cells;
 	unsigned int	(*get_flags)(const __be32 *addr);
···
 }
 
 static u64 of_bus_default_map(__be32 *addr, const __be32 *range,
-		int na, int ns, int pna)
+		int na, int ns, int pna, int fna)
 {
 	u64 cp, s, da;
 
-	cp = of_read_number(range, na);
+	cp = of_read_number(range + fna, na - fna);
 	s  = of_read_number(range + na + pna, ns);
-	da = of_read_number(addr, na);
+	da = of_read_number(addr + fna, na - fna);
 
 	pr_debug("default map, cp=%llx, s=%llx, da=%llx\n", cp, s, da);
 
···
 }
 
 static u64 of_bus_default_flags_map(__be32 *addr, const __be32 *range, int na,
-				    int ns, int pna)
+				    int ns, int pna, int fna)
 {
-	u64 cp, s, da;
-
 	/* Check that flags match */
 	if (*addr != *range)
 		return OF_BAD_ADDR;
 
-	/* Read address values, skipping high cell */
-	cp = of_read_number(range + 1, na - 1);
-	s  = of_read_number(range + na + pna, ns);
-	da = of_read_number(addr + 1, na - 1);
-
-	pr_debug("default flags map, cp=%llx, s=%llx, da=%llx\n", cp, s, da);
-
-	if (da < cp || da >= (cp + s))
-		return OF_BAD_ADDR;
-	return da - cp;
+	return of_bus_default_map(addr, range, na, ns, pna, fna);
 }
 
 static int of_bus_default_flags_translate(__be32 *addr, u64 offset, int na)
···
 }
 
 static u64 of_bus_pci_map(__be32 *addr, const __be32 *range, int na, int ns,
-		int pna)
+		int pna, int fna)
 {
-	u64 cp, s, da;
 	unsigned int af, rf;
 
 	af = of_bus_pci_get_flags(addr);
···
 	if ((af ^ rf) & (IORESOURCE_MEM | IORESOURCE_IO))
 		return OF_BAD_ADDR;
 
-	/* Read address values, skipping high cell */
-	cp = of_read_number(range + 1, na - 1);
-	s  = of_read_number(range + na + pna, ns);
-	da = of_read_number(addr + 1, na - 1);
-
-	pr_debug("PCI map, cp=%llx, s=%llx, da=%llx\n", cp, s, da);
-
-	if (da < cp || da >= (cp + s))
-		return OF_BAD_ADDR;
-	return da - cp;
+	return of_bus_default_map(addr, range, na, ns, pna, fna);
 }
 
 #endif /* CONFIG_PCI */
···
 }
 
 static u64 of_bus_isa_map(__be32 *addr, const __be32 *range, int na, int ns,
-		int pna)
+		int pna, int fna)
 {
-	u64 cp, s, da;
-
 	/* Check address type match */
 	if ((addr[0] ^ range[0]) & cpu_to_be32(1))
 		return OF_BAD_ADDR;
 
-	/* Read address values, skipping high cell */
-	cp = of_read_number(range + 1, na - 1);
-	s  = of_read_number(range + na + pna, ns);
-	da = of_read_number(addr + 1, na - 1);
-
-	pr_debug("ISA map, cp=%llx, s=%llx, da=%llx\n", cp, s, da);
-
-	if (da < cp || da >= (cp + s))
-		return OF_BAD_ADDR;
-	return da - cp;
+	return of_bus_default_map(addr, range, na, ns, pna, fna);
 }
 
 static unsigned int of_bus_isa_get_flags(const __be32 *addr)
···
 	rlen /= 4;
 	rone = na + pna + ns;
 	for (; rlen >= rone; rlen -= rone, ranges += rone) {
-		offset = bus->map(addr, ranges, na, ns, pna);
+		offset = bus->map(addr, ranges, na, ns, pna, bus->flag_cells);
 		if (offset != OF_BAD_ADDR)
 			break;
 	}