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>

diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
index 702c678de1166bd7cbef012cb2c00d556f85666c..85bc601e9a0d43ffd89669eac4b359de99566083 100644 (file)
--- a/arch/mips/kernel/setup.c
+++ b/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;