--- zzzz-none-000/linux-3.10.107/arch/arc/kernel/devtree.c	2017-06-27 09:49:32.000000000 +0000
+++ scorpion-7490-727/linux-3.10.107/arch/arc/kernel/devtree.c	2021-02-04 17:41:59.000000000 +0000
@@ -14,14 +14,44 @@
 #include <linux/memblock.h>
 #include <linux/of.h>
 #include <linux/of_fdt.h>
-#include <asm/prom.h>
 #include <asm/clk.h>
 #include <asm/mach_desc.h>
 
-/* called from unflatten_device_tree() to bootstrap devicetree itself */
-void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
+#ifdef CONFIG_SERIAL_EARLYCON
+
+static unsigned int __initdata arc_base_baud;
+
+unsigned int __init arc_early_base_baud(void)
 {
-	return __va(memblock_alloc(size, align));
+	return arc_base_baud/16;
+}
+
+static void __init arc_set_early_base_baud(unsigned long dt_root)
+{
+	unsigned int core_clk = arc_get_core_freq();
+
+	if (of_flat_dt_is_compatible(dt_root, "abilis,arc-tb10x"))
+		arc_base_baud = core_clk/3;
+	else if (of_flat_dt_is_compatible(dt_root, "snps,arc-sdp"))
+		arc_base_baud = 33333333;	/* Fixed 33MHz clk (AXS10x) */
+	else
+		arc_base_baud = core_clk;
+}
+#else
+#define arc_set_early_base_baud(dt_root)
+#endif
+
+static const void * __init arch_get_next_mach(const char *const **match)
+{
+	static const struct machine_desc *mdesc = __arch_info_begin;
+	const struct machine_desc *m = mdesc;
+
+	if (m >= __arch_info_end)
+		return NULL;
+
+	mdesc++;
+	*match = m->dt_compat;
+	return m;
 }
 
 /**
@@ -31,93 +61,26 @@
  * If a dtb was passed to the kernel, then use it to choose the correct
  * machine_desc and to setup the system.
  */
-struct machine_desc * __init setup_machine_fdt(void *dt)
+const struct machine_desc * __init setup_machine_fdt(void *dt)
 {
-	struct boot_param_header *devtree = dt;
-	struct machine_desc *mdesc = NULL, *mdesc_best = NULL;
-	unsigned int score, mdesc_score = ~1;
+	const struct machine_desc *mdesc;
 	unsigned long dt_root;
-	const char *model, *compat;
-	void *clk;
-	char manufacturer[16];
-	unsigned long len;
+	const void *clk;
+	int len;
 
-	/* check device tree validity */
-	if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
+	if (!early_init_dt_scan(dt))
 		return NULL;
 
-	initial_boot_params = devtree;
-	dt_root = of_get_flat_dt_root();
-
-	/*
-	 * The kernel could be multi-platform enabled, thus could have many
-	 * "baked-in" machine descriptors. Search thru all for the best
-	 * "compatible" string match.
-	 */
-	for_each_machine_desc(mdesc) {
-		score = of_flat_dt_match(dt_root, mdesc->dt_compat);
-		if (score > 0 && score < mdesc_score) {
-			mdesc_best = mdesc;
-			mdesc_score = score;
-		}
-	}
-	if (!mdesc_best) {
-		const char *prop;
-		long size;
-
-		pr_err("\n unrecognized device tree list:\n[ ");
-
-		prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
-		if (prop) {
-			while (size > 0) {
-				printk("'%s' ", prop);
-				size -= strlen(prop) + 1;
-				prop += strlen(prop) + 1;
-			}
-		}
-		printk("]\n\n");
-
+	mdesc = of_flat_dt_match_machine(NULL, arch_get_next_mach);
+	if (!mdesc)
 		machine_halt();
-	}
-
-	/* compat = "<manufacturer>,<model>" */
-	compat =  mdesc_best->dt_compat[0];
-
-	model = strchr(compat, ',');
-	if (model)
-		model++;
-
-	strlcpy(manufacturer, compat, model ? model - compat : strlen(compat));
-
-	pr_info("Board \"%s\" from %s (Manufacturer)\n", model, manufacturer);
-
-	/* Retrieve various information from the /chosen node */
-	of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
-
-	/* Initialize {size,address}-cells info */
-	of_scan_flat_dt(early_init_dt_scan_root, NULL);
-
-	/* Setup memory, calling early_init_dt_add_memory_arch */
-	of_scan_flat_dt(early_init_dt_scan_memory, NULL);
 
+	dt_root = of_get_flat_dt_root();
 	clk = of_get_flat_dt_prop(dt_root, "clock-frequency", &len);
 	if (clk)
 		arc_set_core_freq(of_read_ulong(clk, len/4));
 
-	return mdesc_best;
-}
+	arc_set_early_base_baud(dt_root);
 
-/*
- * Copy the flattened DT out of .init since unflattening doesn't copy strings
- * and the normal DT APIs refs them from orig flat DT
- */
-void __init copy_devtree(void)
-{
-	void *alloc = early_init_dt_alloc_memory_arch(
-			be32_to_cpu(initial_boot_params->totalsize), 64);
-	if (alloc) {
-		memcpy(alloc, initial_boot_params,
-				be32_to_cpu(initial_boot_params->totalsize));
-		initial_boot_params = alloc;
-	}
+	return mdesc;
 }