[PATCH v7 16/23] arm64: Add an aliasing facility for the idreg override

Marc Zyngier
2021-02-08T10:17:00Z

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 <maz@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: David Brazdil <dbrazdil@google.com>
---
arch/arm64/kernel/idreg-override.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
index 2da11bf60195..226bac544e20 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c
@@ -16,6 +16,8 @@

#define FTR_DESC_NAME_LEN 20
#define FTR_DESC_FIELD_LEN 10
+#define FTR_ALIAS_NAME_LEN 30
+#define FTR_ALIAS_OPTION_LEN 80

struct ftr_set_desc {
char name[FTR_DESC_NAME_LEN];
@@ -39,6 +41,12 @@ static const struct ftr_set_desc * const regs[] __initconst = {
&mmfr1,
};

+static const struct {
+ char alias[FTR_ALIAS_NAME_LEN];
+ char feature[FTR_ALIAS_OPTION_LEN];
+} aliases[] __initconst = {
+};
+
static int __init find_field(const char *cmdline,
const struct ftr_set_desc *reg, int f, u64 *v)
{
@@ -81,7 +89,7 @@ static void __init match_options(const char *cmdline)
}
}

-static __init void __parse_cmdline(const char *cmdline)
+static __init void __parse_cmdline(const char *cmdline, bool parse_aliases)
{
do {
char buf[256];
@@ -105,6 +113,9 @@ static __init void __parse_cmdline(const char *cmdline)

match_options(buf);

+ for (i = 0; parse_aliases && i < ARRAY_SIZE(aliases); i++)
+ if (parameq(buf, aliases[i].alias))
+ __parse_cmdline(aliases[i].feature, false);
} while (1);
}

@@ -127,14 +138,14 @@ static __init void parse_cmdline(void)
if (!prop)
goto out;

- __parse_cmdline(prop);
+ __parse_cmdline(prop, true);

if (!IS_ENABLED(CONFIG_CMDLINE_EXTEND))
return;
}

out:
- __parse_cmdline(CONFIG_CMDLINE);
+ __parse_cmdline(CONFIG_CMDLINE, true);
}

/* Keep checkers quiet */
--
2.29.2