console: Add extensible console matching

Add match() method to struct console which allows the console to
perform console command line matching instead of (or in addition to)
default console matching (ie., by fixed name and index).

The match() method returns 0 to indicate a successful match; normal
console matching occurs if no match() method is defined or the
match() method returns non-zero. The match() method is expected to set
the console index if required.

Re-implement earlycon-to-console-handoff with direct matching of
"console=uart|uart8250,..." to the 8250 ttyS console.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 18 insertions, 34 deletions

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 26f899809539..dda959221086 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -2017,24 +2017,6 @@ int add_preferred_console(char *name, int idx, char *options)
         return __add_preferred_console(name, idx, options, NULL);
 }
 
-int update_console_cmdline(char *name, int idx, char *name_new, int idx_new, char *options)
-{
-        struct console_cmdline *c;
-        int i;
-
-        for (i = 0, c = console_cmdline;
-             i < MAX_CMDLINECONSOLES && c->name[0];
-             i++, c++)
-                if (strcmp(c->name, name) == 0 && c->index == idx) {
-                        strlcpy(c->name, name_new, sizeof(c->name));
-                        c->options = options;
-                        c->index = idx_new;
-                        return i;
-                }
-        /* not found */
-        return -1;
-}
-
 bool console_suspend_enabled = true;
 EXPORT_SYMBOL(console_suspend_enabled);
 
@@ -2436,9 +2418,6 @@ void register_console(struct console *newcon)
         if (preferred_console < 0 || bcon || !console_drivers)
                 preferred_console = selected_console;
 
-        if (newcon->early_setup)
-                newcon->early_setup();
-
         /*
          *      See if we want to use this console driver. If we
          *      didn't select a console we take the first one
@@ -2464,21 +2443,26 @@ void register_console(struct console *newcon)
         for (i = 0, c = console_cmdline;
              i < MAX_CMDLINECONSOLES && c->name[0];
              i++, c++) {
-                BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name));
-                if (strcmp(c->name, newcon->name) != 0)
-                        continue;
-                if (newcon->index >= 0 &&
-                    newcon->index != c->index)
-                        continue;
-                if (newcon->index < 0)
-                        newcon->index = c->index;
+                if (!newcon->match ||
+                    newcon->match(newcon, c->name, c->index, c->options) != 0) {
+                        /* default matching */
+                        BUILD_BUG_ON(sizeof(c->name) != sizeof(newcon->name));
+                        if (strcmp(c->name, newcon->name) != 0)
+                                continue;
+                        if (newcon->index >= 0 &&
+                            newcon->index != c->index)
+                                continue;
+                        if (newcon->index < 0)
+                                newcon->index = c->index;
 
-                if (_braille_register_console(newcon, c))
-                        return;
+                        if (_braille_register_console(newcon, c))
+                                return;
+
+                        if (newcon->setup &&
+                            newcon->setup(newcon, c->options) != 0)
+                                break;
+                }
 
-                if (newcon->setup &&
-                    newcon->setup(newcon, console_cmdline[i].options) != 0)
-                        break;
                 newcon->flags |= CON_ENABLED;
                 if (i == selected_console) {
                         newcon->flags |= CON_CONSDEV;