params: <level>_initcall-like kernel parameters

This patch adds a set of macros that can be used to declare
kernel parameters to be parsed _before_ initcalls at a chosen
level are executed.  We rename the now-unused "flags" field of
struct kernel_param as the level.  It's signed, for when we
use this for early params as well, in future.

Linker macro collating init calls had to be modified in order
to add additional symbols between levels that are later used
by the init code to split the calls into blocks.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 12 insertions, 4 deletions

diff --git a/kernel/params.c b/kernel/params.c
index 508828afb874..f37d82631347 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -87,6 +87,8 @@ static int parse_one(char *param,
                      char *val,
                      const struct kernel_param *params,
                      unsigned num_params,
+                     s16 min_level,
+                     s16 max_level,
                      int (*handle_unknown)(char *param, char *val))
 {
         unsigned int i;
@@ -95,6 +97,9 @@ static int parse_one(char *param,
         /* Find parameter */
         for (i = 0; i < num_params; i++) {
                 if (parameq(param, params[i].name)) {
+                        if (params[i].level < min_level
+                            || params[i].level > max_level)
+                                return 0;
                         /* No one handled NULL, so do it here. */
                         if (!val && params[i].ops->set != param_set_bool
                             && params[i].ops->set != param_set_bint)
@@ -174,6 +179,8 @@ int parse_args(const char *name,
                char *args,
                const struct kernel_param *params,
                unsigned num,
+               s16 min_level,
+               s16 max_level,
                int (*unknown)(char *param, char *val))
 {
         char *param, *val;
@@ -189,7 +196,8 @@ int parse_args(const char *name,
 
                 args = next_arg(args, &param, &val);
                 irq_was_disabled = irqs_disabled();
-                ret = parse_one(param, val, params, num, unknown);
+                ret = parse_one(param, val, params, num,
+                                min_level, max_level, unknown);
                 if (irq_was_disabled && !irqs_disabled()) {
                         printk(KERN_WARNING "parse_args(): option '%s' enabled "
                                         "irq's!\n", param);
@@ -374,7 +382,7 @@ static int param_array(const char *name,
                        unsigned int min, unsigned int max,
                        void *elem, int elemsize,
                        int (*set)(const char *, const struct kernel_param *kp),
-                       u16 flags,
+                       s16 level,
                        unsigned int *num)
 {
         int ret;
@@ -384,7 +392,7 @@ static int param_array(const char *name,
         /* Get the name right for errors. */
         kp.name = name;
         kp.arg = elem;
-        kp.flags = flags;
+        kp.level = level;
 
         *num = 0;
         /* We expect a comma-separated list of values. */
@@ -425,7 +433,7 @@ static int param_array_set(const char *val, const struct kernel_param *kp)
         unsigned int temp_num;
 
         return param_array(kp->name, val, 1, arr->max, arr->elem,
-                           arr->elemsize, arr->ops->set, kp->flags,
+                           arr->elemsize, arr->ops->set, kp->level,
                            arr->num ?: &temp_num);
 }