@@ -538,8 +538,65 @@ static void __init check_kernel_sections_mem(void)
}
}
-#define USE_PROM_CMDLINE IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_BOOTLOADER)
-#define USE_DTB_CMDLINE IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_DTB)
+static int __init cmdline_scan_chosen(unsigned long node, const char *uname,
+ int depth, void *data)
+{
+ const char *p;
+ int l;
+
+ if (depth != 1 || !data ||
+ (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
+ return 0;
+
+ /* Retrieve command line */
+ p = of_get_flat_dt_prop(node, "bootargs", &l);
+ if (p != NULL && l > 0)
+ strlcpy(data, p, min(l, COMMAND_LINE_SIZE));
+
+ return 1;
+}
+
+static void __init init_boot_cmdline(char **cmdline_p)
+{
+ /*
+ * If CMDLINE_OVERRIDE is enabled then initializing the command line is
+ * trivial - we simply use the built-in command line unconditionally &
+ * unmodified.
+ */
+ if (IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
+ strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
+ return;
+ }
+
+ /*
+ * If we're configured to take boot arguments from DT, look for those
+ * now. Note that we clear boot_command_line, undoing anything
+ * early_init_dt_scan_chosen() did to boot_command_line.
+ */
+ boot_command_line[0] = 0;
+ if (IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_DTB))
+ of_scan_flat_dt(cmdline_scan_chosen, boot_command_line);
+
+ /*
+ * If we didn't get any arguments from DT (regardless of whether that's
+ * because we weren't configured to look for them, or because we looked
+ * & found none) then we'll take arguments from the bootloader.
+ * plat_mem_setup() should have filled arcs_cmdline with arguments from
+ * the bootloader, so we simply copy them here.
+ */
+ if (!boot_command_line[0])
+ strlcpy(boot_command_line, arcs_cmdline, COMMAND_LINE_SIZE);
+
+ /*
+ * If the user specified a built-in command line, we append it to
+ * boot_command_line here.
+ */
+ if (IS_ENABLED(CONFIG_CMDLINE_BOOL) && builtin_cmdline[0]) {
+ if (boot_command_line[0])
+ strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
+ strlcat(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
+ }
+}
/*
* arch_mem_init - initialize memory management subsystem
@@ -567,36 +624,12 @@ static void __init arch_mem_init(char **cmdline_p)
{
extern void plat_mem_setup(void);
- /*
- * Initialize boot_command_line to an innocuous but non-empty string in
- * order to prevent early_init_dt_scan_chosen() from copying
- * CONFIG_CMDLINE into it without our knowledge. We handle
- * CONFIG_CMDLINE ourselves below & don't want to duplicate its
- * content because repeating arguments can be problematic.
- */
- strlcpy(boot_command_line, " ", COMMAND_LINE_SIZE);
-
/* call board setup routine */
plat_mem_setup();
memblock_set_bottom_up(true);
-#if defined(CONFIG_CMDLINE_BOOL) && defined(CONFIG_CMDLINE_OVERRIDE)
- strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
-#else
- if ((USE_PROM_CMDLINE && arcs_cmdline[0]) ||
- (USE_DTB_CMDLINE && !boot_command_line[0]))
- strlcpy(boot_command_line, arcs_cmdline, COMMAND_LINE_SIZE);
-
-#if defined(CONFIG_CMDLINE_BOOL)
- if (builtin_cmdline[0]) {
- if (boot_command_line[0])
- strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
- strlcat(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
- }
-#endif
-#endif
+ init_boot_cmdline(cmdline_p);
strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
-
*cmdline_p = command_line;
parse_early_param();
Our current code to initialize boot_command_line is a mess. Some of this is due to the addition of too many options over the years, and some of this is due to workarounds for early_init_dt_scan_chosen() performing actions specific to options from other architectures that probably shouldn't be in generic code. Clean this up by introducing a new init_boot_cmdline() function that simplifies the initialization somewhat. The major changes are: - Because init_boot_cmdline() is a function it can return early in the CONFIG_CMDLINE_OVERRIDE case. - We clear boot_command_line rather than inheriting whatever early_init_dt_scan_chosen() may have left us. This means we no longer need to set boot_command_line to a space character in an attempt to prevent early_init_dt_scan_chosen() from copying CONFIG_CMDLINE into boot_command_line without us knowing about it. - Indirection via USE_PROM_CMDLINE & USE_DTB_CMDLINE macros is removed; they seemingly served only to obfuscate the code. - The logic is cleaner, clearer & commented. Two minor drawbacks of this approach are: 1) We call of_scan_flat_dt(), which means we scan through the DT again. The overhead is fairly minimal & shouldn't be noticeable. 2) cmdline_scan_chosen() duplicates a small amount of the logic from early_init_dt_scan_chosen(). Alternatives might be to allow the generic FDT code to keep & expose a copy of the arguments taken from the /chosen node's bootargs property, or to introduce a function like early_init_dt_scan_chosen() that retrieves them without modification to handle CONFIG_CMDLINE. Neither of these sounds particularly cleaner though, and this way we at least keep the extra work in arch/mips. Signed-off-by: Paul Burton <paul.burton@mips.com> --- arch/mips/kernel/setup.c | 87 +++++++++++++++++++++++++++------------- 1 file changed, 60 insertions(+), 27 deletions(-)