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| author | Gregory CLEMENT <gregory.clement@free-electrons.com> | 2015-08-06 16:07:04 +0200 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2015-08-07 20:57:02 +0200 |
| commit | 998ef5d81c74c752d74c7925bc370909b84adb9d (patch) | |
| tree | 1e1b8b2385fdf3bba639ef55110a389db914f483 /arch/arm/kernel/head.S | |
| parent | ARM: 8405/1: VDSO: fix regression with toolchains lacking ld.bfd executable (diff) | |
| download | linux-998ef5d81c74c752d74c7925bc370909b84adb9d.tar.xz linux-998ef5d81c74c752d74c7925bc370909b84adb9d.zip | |
ARM: 8408/1: Fix the secondary_startup function in Big Endian case
Since the commit "b2c3e38a5471 ARM: redo TTBR setup code for LPAE",
the setup code had been reworked. As a result the secondary CPUs
failed to come online in Big Endian.
As explained by Russell, the new code expected the value in r4/r5 to
be the least significant 32bits in r4 and the most significant 32bits
in r5. However, in the secondary code, we load this using ldrd, which
on BE reverses that.
This patch swap r4/r5 after the ldrd. It is done using the xor
instructions in order to not use a temporary register.
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel/head.S')
| -rw-r--r-- | arch/arm/kernel/head.S | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index bd755d97e459..29e2991465cb 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -399,6 +399,9 @@ ENTRY(secondary_startup) sub lr, r4, r5 @ mmu has been enabled add r3, r7, lr ldrd r4, [r3, #0] @ get secondary_data.pgdir +ARM_BE8(eor r4, r4, r5) @ Swap r5 and r4 in BE: +ARM_BE8(eor r5, r4, r5) @ it can be done in 3 steps +ARM_BE8(eor r4, r4, r5) @ without using a temp reg. ldr r8, [r3, #8] @ get secondary_data.swapper_pg_dir badr lr, __enable_mmu @ return address mov r13, r12 @ __secondary_switched address |