arm64: Store struct thread_info in sp_el0

There is need for figuring out how to manage struct thread_info data when
IRQ stack is introduced. struct thread_info information should be copied
to IRQ stack under the current thread_info calculation logic whenever
context switching is invoked. This is too expensive to keep supporting
the approach.

Instead, this patch pays attention to sp_el0 which is an unused scratch
register in EL1 context. sp_el0 utilization not only simplifies the
management, but also prevents text section size from being increased
largely due to static allocated IRQ stack as removing masking operation
using THREAD_SIZE in many places.

Reviewed-by: Catalin Marinas <[email protected]>
Signed-off-by: Jungseok Lee <[email protected]>
Signed-off-by: James Morse <[email protected]>
Signed-off-by: Will Deacon <[email protected]>

0 files changed, 0 insertions, 0 deletions