of/fdt: add FDT address translation support (e06e8b27) · Commits · e / devices / android_kernel_xiaomi_markw

drivers/of/Makefile

+2 −0

Original line number	Diff line number	Diff line
		obj-y = base.o device.o platform.o
		obj-$(CONFIG_OF_FLATTREE) += fdt.o
		obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o
		obj-$(CONFIG_OF_PROMTREE) += pdt.o
		obj-$(CONFIG_OF_ADDRESS) += address.o
		obj-$(CONFIG_OF_IRQ) += irq.o
		@@ -12,3 +13,4 @@ obj-$(CONFIG_OF_MTD) += of_mtd.o
		obj-$(CONFIG_OF_RESERVED_MEM) += of_reserved_mem.o

		CFLAGS_fdt.o = -I$(src)/../../scripts/dtc/libfdt
		CFLAGS_fdt_address.o = -I$(src)/../../scripts/dtc/libfdt

drivers/of/fdt_address.c

0 → 100644

+241 −0

Original line number	Diff line number	Diff line
		/*
		* FDT Address translation based on u-boot fdt_support.c which in turn was
		* based on the kernel unflattened DT address translation code.
		*
		* (C) Copyright 2007
		* Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com
		*
		* Copyright 2010-2011 Freescale Semiconductor, Inc.
		*
		* This program is free software; you can redistribute it and/or modify
		* it under the terms of the GNU General Public License as published by
		* the Free Software Foundation; either version 2, or (at your option)
		* any later version.
		*/
		#include <linux/kernel.h>
		#include <linux/libfdt.h>
		#include <linux/of.h>
		#include <linux/of_fdt.h>
		#include <linux/sizes.h>

		/* Max address size we deal with */
		#define OF_MAX_ADDR_CELLS 4
		#define OF_CHECK_COUNTS(na, ns) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS && \
		(ns) > 0)

		/* Debug utility */
		#ifdef DEBUG
		static void __init of_dump_addr(const char s, const __be32 addr, int na)
		{
		pr_debug("%s", s);
		while(na--)
		pr_cont(" %08x", *(addr++));
		pr_debug("\n");
		}
		#else
		static void __init of_dump_addr(const char s, const __be32 addr, int na) { }
		#endif

		/* Callbacks for bus specific translators */
		struct of_bus {
		void (count_cells)(const void blob, int parentoffset,
		int addrc, int sizec);
		u64 (map)(__be32 addr, const __be32 *range,
		int na, int ns, int pna);
		int (translate)(__be32 addr, u64 offset, int na);
		};

		/* Default translator (generic bus) */
		static void __init fdt_bus_default_count_cells(const void *blob, int parentoffset,
		int addrc, int sizec)
		{
		const __be32 *prop;

		if (addrc) {
		prop = fdt_getprop(blob, parentoffset, "#address-cells", NULL);
		if (prop)
		*addrc = be32_to_cpup(prop);
		else
		*addrc = dt_root_addr_cells;
		}

		if (sizec) {
		prop = fdt_getprop(blob, parentoffset, "#size-cells", NULL);
		if (prop)
		*sizec = be32_to_cpup(prop);
		else
		*sizec = dt_root_size_cells;
		}
		}

		static u64 __init fdt_bus_default_map(__be32 addr, const __be32 range,
		int na, int ns, int pna)
		{
		u64 cp, s, da;

		cp = of_read_number(range, na);
		s = of_read_number(range + na + pna, ns);
		da = of_read_number(addr, na);

		pr_debug("FDT: default map, cp=%llx, s=%llx, da=%llx\n",
		cp, s, da);

		if (da < cp \|\| da >= (cp + s))
		return OF_BAD_ADDR;
		return da - cp;
		}

		static int __init fdt_bus_default_translate(__be32 *addr, u64 offset, int na)
		{
		u64 a = of_read_number(addr, na);
		memset(addr, 0, na * 4);
		a += offset;
		if (na > 1)
		addr[na - 2] = cpu_to_fdt32(a >> 32);
		addr[na - 1] = cpu_to_fdt32(a & 0xffffffffu);

		return 0;
		}

		/* Array of bus specific translators */
		static const struct of_bus of_busses[] __initconst = {
		/* Default */
		{
		.count_cells = fdt_bus_default_count_cells,
		.map = fdt_bus_default_map,
		.translate = fdt_bus_default_translate,
		},
		};

		static int __init fdt_translate_one(const void *blob, int parent,
		const struct of_bus *bus,
		const struct of_bus pbus, __be32 addr,
		int na, int ns, int pna, const char *rprop)
		{
		const __be32 *ranges;
		int rlen;
		int rone;
		u64 offset = OF_BAD_ADDR;

		ranges = fdt_getprop(blob, parent, rprop, &rlen);
		if (!ranges)
		return 1;
		if (rlen == 0) {
		offset = of_read_number(addr, na);
		memset(addr, 0, pna * 4);
		pr_debug("FDT: empty ranges, 1:1 translation\n");
		goto finish;
		}

		pr_debug("FDT: walking ranges...\n");

		/* Now walk through the ranges */
		rlen /= 4;
		rone = na + pna + ns;
		for (; rlen >= rone; rlen -= rone, ranges += rone) {
		offset = bus->map(addr, ranges, na, ns, pna);
		if (offset != OF_BAD_ADDR)
		break;
		}
		if (offset == OF_BAD_ADDR) {
		pr_debug("FDT: not found !\n");
		return 1;
		}
		memcpy(addr, ranges + na, 4 * pna);

		finish:
		of_dump_addr("FDT: parent translation for:", addr, pna);
		pr_debug("FDT: with offset: %llx\n", offset);

		/* Translate it into parent bus space */
		return pbus->translate(addr, offset, pna);
		}

		/*
		* Translate an address from the device-tree into a CPU physical address,
		* this walks up the tree and applies the various bus mappings on the
		* way.
		*
		* Note: We consider that crossing any level with #size-cells == 0 to mean
		* that translation is impossible (that is we are not dealing with a value
		* that can be mapped to a cpu physical address). This is not really specified
		* that way, but this is traditionally the way IBM at least do things
		*/
		u64 __init fdt_translate_address(const void *blob, int node_offset)
		{
		int parent, len;
		const struct of_bus bus, pbus;
		const __be32 *reg;
		__be32 addr[OF_MAX_ADDR_CELLS];
		int na, ns, pna, pns;
		u64 result = OF_BAD_ADDR;

		pr_debug("FDT: translation for device %s \n",
		fdt_get_name(blob, node_offset, NULL));

		reg = fdt_getprop(blob, node_offset, "reg", &len);
		if (!reg) {
		pr_err("FDT: warning: device tree node '%s' has no address.\n",
		fdt_get_name(blob, node_offset, NULL));
		goto bail;
		}

		/* Get parent & match bus type */
		parent = fdt_parent_offset(blob, node_offset);
		if (parent < 0)
		goto bail;
		bus = &of_busses[0];

		/* Cound address cells & copy address locally */
		bus->count_cells(blob, parent, &na, &ns);
		if (!OF_CHECK_COUNTS(na, ns)) {
		pr_err("FDT: Bad cell count for %s\n",
		fdt_get_name(blob, node_offset, NULL));
		goto bail;
		}
		memcpy(addr, reg, na * 4);

		pr_debug("FDT: bus (na=%d, ns=%d) on %s\n",
		na, ns, fdt_get_name(blob, parent, NULL));
		of_dump_addr("OF: translating address:", addr, na);

		/* Translate */
		for (;;) {
		/* Switch to parent bus */
		node_offset = parent;
		parent = fdt_parent_offset(blob, node_offset);

		/* If root, we have finished */
		if (parent < 0) {
		pr_debug("FDT: reached root node\n");
		result = of_read_number(addr, na);
		break;
		}

		/* Get new parent bus and counts */
		pbus = &of_busses[0];
		pbus->count_cells(blob, parent, &pna, &pns);
		if (!OF_CHECK_COUNTS(pna, pns)) {
		pr_err("FDT: Bad cell count for %s\n",
		fdt_get_name(blob, node_offset, NULL));
		break;
		}

		pr_debug("FDT: parent bus (na=%d, ns=%d) on %s\n",
		pna, pns, fdt_get_name(blob, parent, NULL));

		/* Apply bus translation */
		if (fdt_translate_one(blob, node_offset, bus, pbus,
		addr, na, ns, pna, "ranges"))
		break;

		/* Complete the move up one level */
		na = pna;
		ns = pns;
		bus = pbus;

		of_dump_addr("FDT: one level translation:", addr, na);
		}
		bail:
		return result;
		}

include/linux/of_fdt.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -83,6 +83,7 @@ extern void unflatten_device_tree(void);
		extern void unflatten_and_copy_device_tree(void);
		extern void early_init_devtree(void *);
		extern void early_get_first_memblock_info(void , phys_addr_t );
		extern u64 fdt_translate_address(const void *blob, int node_offset);
		#else /* CONFIG_OF_FLATTREE */
		static inline void early_init_fdt_scan_reserved_mem(void) {}
		static inline const char *of_flat_dt_get_machine_name(void) { return NULL; }