By saving the pointer pointing to thread_info.flags, gcc copies r2
in a non-volatile register.
We know 'current' doesn't change, so avoid that intermediaite pointer.
Reduces null_syscall benchmark by 2 cycles (322 => 320 cycles)
On PPC64, gcc seems to know that 'current' is not changing, and it keeps
it in a non volatile register to avoid multiple read of 'current' in paca.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ad0363ff0ff8c125f40e1cdc589a85bbd7e31693.1612946484.git.christophe.leroy@csgroup.eu
Only book3s/64 has scv. No need to check the 0x7ff0 trap on 32 or 64e.
For that, add a helper trap_is_unsupported_scv() similar to
trap_is_scv().
And ignore the scv parameter in syscall_exit_prepare (Save 14 cycles
346 => 332 cycles)
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/fb87b205ae8eb8c623f33bb316801acf95a831e6.1612898425.git.christophe.leroy@csgroup.eu
To allow building interrupt.c on PPC32, ifdef out specific PPC64
code or use helpers which are available on both PP32 and PPC64
Modify Makefile to always build interrupt.o
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/ba073ad67bd971a88ce331b65d6655523b54c794.1612796617.git.christophe.leroy@csgroup.eu
