[PATCH v4 15/21] arm64: Add an aliasing facility for the idreg override

[Marc Zyngier]

In order to map the override of idregs to options that a user
can easily understand, let's introduce yet another option
array, which maps an option to the corresponding idreg options.

Signed-off-by: Marc Zyngier <m...@kernel.org>
---
 arch/arm64/kernel/idreg-override.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/arch/arm64/kernel/idreg-override.c 
b/arch/arm64/kernel/idreg-override.c
index 75d9845f489b..16bc8b3b93ae 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c
@@ -37,6 +37,12 @@ static const struct reg_desc * const regs[] __initdata = {
        &mmfr1,
 };
 
+static const struct {
+       const char * const      alias;
+       const char * const      feature;
+} aliases[] __initdata = {
+};
+
 static int __init find_field(const char *cmdline, const struct reg_desc *reg,
                             int f, u64 *v)
 {
@@ -80,6 +86,18 @@ static void __init match_options(const char *cmdline)
        }
 }
 
+static __init void match_aliases(const char *cmdline)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(aliases); i++) {
+               char *str = strstr(cmdline, aliases[i].alias);
+
+               if ((str == cmdline || (str > cmdline && *(str - 1) == ' ')))
+                       match_options(aliases[i].feature);
+       }
+}
+
 static __init void parse_cmdline(void)
 {
        if (!IS_ENABLED(CONFIG_CMDLINE_FORCE)) {
@@ -100,6 +118,7 @@ static __init void parse_cmdline(void)
                        goto out;
 
                match_options(prop);
+               match_aliases(prop);
 
                if (!IS_ENABLED(CONFIG_CMDLINE_EXTEND))
                        return;
@@ -107,6 +126,7 @@ static __init void parse_cmdline(void)
 
 out:
        match_options(CONFIG_CMDLINE);
+       match_aliases(CONFIG_CMDLINE);
 }
 
 void __init init_shadow_regs(void)
-- 
2.29.2