[v2,2/2] arm64: Drop support for CMDLINE_EXTEND
diff mbox series

Message ID 20210303134927.18975-3-will@kernel.org
State Accepted
Commit cae118b6acc309539b33339e846cbb19187c164c
Headers show
  • Fix arm64 CONFIG_CMDLINE handling and remove CMDLINE_EXTEND
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Commit Message

Will Deacon March 3, 2021, 1:49 p.m. UTC
The documented behaviour for CMDLINE_EXTEND is that the arguments from
the bootloader are appended to the built-in kernel command line. This
also matches the option parsing behaviour for the EFI stub and early ID
register overrides.

Bizarrely, the fdt behaviour is the other way around: appending the
built-in command line to the bootloader arguments, resulting in a
command-line that doesn't necessarily line-up with the parsing order and
definitely doesn't line-up with the documented behaviour.

As it turns out, there is a proposal [1] to replace CMDLINE_EXTEND with
CMDLINE_PREPEND and CMDLINE_APPEND options which should hopefully make
the intended behaviour much clearer. While we wait for those to land,
drop CMDLINE_EXTEND for now as there appears to be little enthusiasm for
changing the current FDT behaviour.

[1] https://lore.kernel.org/lkml/20190319232448.45964-2-danielwa@cisco.com/

Cc: Max Uvarov <muvarov@gmail.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/CAL_JsqJX=TCCs7=gg486r9TN4NYscMTCLNfqJF9crskKPq-bTg@mail.gmail.com
Signed-off-by: Will Deacon <will@kernel.org>
 arch/arm64/Kconfig                 | 6 ------
 arch/arm64/kernel/idreg-override.c | 5 +----
 2 files changed, 1 insertion(+), 10 deletions(-)

diff mbox series

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1f212b47a48a..f15418332d16 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1855,12 +1855,6 @@  config CMDLINE_FROM_BOOTLOADER
 	  the boot loader doesn't provide any, the default kernel command
 	  string provided in CMDLINE will be used.
-	bool "Extend bootloader kernel arguments"
-	help
-	  The command-line arguments provided by the boot loader will be
-	  appended to the default kernel command string.
 	bool "Always use the default kernel command string"
diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
index cc071712c6f9..83f1c4b92095 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c
@@ -188,11 +188,8 @@  static __init void parse_cmdline(void)
 	const u8 *prop = get_bootargs_cmdline();
-	    !prop) {
 		__parse_cmdline(CONFIG_CMDLINE, true);
-	}
 		__parse_cmdline(prop, true);