arm64: switch_to: calculate cpu context pointer using separate register
authorWill Deacon <will.deacon@arm.com>
Mon, 20 Jul 2015 14:14:53 +0000 (15:14 +0100)
committerCatalin Marinas <catalin.marinas@arm.com>
Wed, 22 Jul 2015 09:56:41 +0000 (10:56 +0100)
commitc0d3fce5e192c6b45a9d8e06aecfcec546f73884
treec74ade93b7c2359bb34acfa704abc7f92d014852
parent52721d9d3334c1cb1f76219a161084094ec634dc
arm64: switch_to: calculate cpu context pointer using separate register

Commit 0c8c0f03e3a2 ("x86/fpu, sched: Dynamically allocate 'struct fpu'")
moved the thread_struct to the bottom of task_struct. As a result, the
offset is now too large to be used in an immediate add on arm64 with
some kernel configs:

arch/arm64/kernel/entry.S: Assembler messages:
arch/arm64/kernel/entry.S:588: Error: immediate out of range
arch/arm64/kernel/entry.S:597: Error: immediate out of range

This patch calculates the offset using an additional register instead of
an immediate offset.

Fixes: 0c8c0f03e3a2 ("x86/fpu, sched: Dynamically allocate 'struct fpu'")
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Olof Johansson <olof@lixom.net>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arch/arm64/kernel/entry.S