MIPS: Setup boot_command_line before plat_mem_setup

Platforms using DT will typically call __dt_setup_arch from
plat_mem_setup. This in turn calls early_init_dt_scan. When
CONFIG_CMDLINE is set, this leads to its value being copied into
boot_command_line by early_init_dt_scan_chosen. If this happens before
the code setting up boot_command_line in arch_mem_init runs, that code
will go on to append CONFIG_CMDLINE (via builtin_cmdline) to
boot_command_line again, duplicating it. For some command line
parameters (eg. earlycon) this can be a problem. Set up
boot_command_line before early_init_dt_scan_chosen gets called such that
it will not write CONFIG_CMDLINE in this scenario & the arguments aren't
duplicated.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Acked-by: Mathieu Malaterre <malat@debian.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Maarten ter Huurne <maarten@treewalker.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18483/
Signed-off-by: James Hogan <jhogan@kernel.org>

arch/mips/kernel/setup.c

@@ -826,25 +826,6 @@ static void __init arch_mem_init(char **cmdline_p)
 	struct memblock_region *reg;
 	extern void plat_mem_setup(void);
 
-	/* call board setup routine */
-	plat_mem_setup();
-
-	/*
-	 * Make sure all kernel memory is in the maps.  The "UP" and
-	 * "DOWN" are opposite for initdata since if it crosses over
-	 * into another memory section you don't want that to be
-	 * freed when the initdata is freed.
-	 */
-	arch_mem_addpart(PFN_DOWN(__pa_symbol(&_text)) << PAGE_SHIFT,
-			 PFN_UP(__pa_symbol(&_edata)) << PAGE_SHIFT,
-			 BOOT_MEM_RAM);
-	arch_mem_addpart(PFN_UP(__pa_symbol(&__init_begin)) << PAGE_SHIFT,
-			 PFN_DOWN(__pa_symbol(&__init_end)) << PAGE_SHIFT,
-			 BOOT_MEM_INIT_RAM);
-
-	pr_info("Determined physical RAM map:\n");
-	print_memory_map();
-
 #if defined(CONFIG_CMDLINE_BOOL) && defined(CONFIG_CMDLINE_OVERRIDE)
 	strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
 #else
@@ -872,6 +853,26 @@ static void __init arch_mem_init(char **cmdline_p)
 	}
 #endif
 #endif
+
+	/* call board setup routine */
+	plat_mem_setup();
+
+	/*
+	 * Make sure all kernel memory is in the maps.  The "UP" and
+	 * "DOWN" are opposite for initdata since if it crosses over
+	 * into another memory section you don't want that to be
+	 * freed when the initdata is freed.
+	 */
+	arch_mem_addpart(PFN_DOWN(__pa_symbol(&_text)) << PAGE_SHIFT,
+			 PFN_UP(__pa_symbol(&_edata)) << PAGE_SHIFT,
+			 BOOT_MEM_RAM);
+	arch_mem_addpart(PFN_UP(__pa_symbol(&__init_begin)) << PAGE_SHIFT,
+			 PFN_DOWN(__pa_symbol(&__init_end)) << PAGE_SHIFT,
+			 BOOT_MEM_INIT_RAM);
+
+	pr_info("Determined physical RAM map:\n");
+	print_memory_map();
+
 	strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
 
 	*cmdline_p = command_line;