This series attempts to improve the speed of interrupts and system calls in two major ways.
Firstly, the SRR/HSRR registers do not need to be reloaded if they were not used or clobbered fur the duration of the interrupt. Secondly, an alternate return location facility is added for soft-masked asynchronous interrupts and then that's used to set everything up for return without having to disable MSR RI or EE. After this series, the entire system call / interrupt handler fast path executes no mtsprs and one mtmsrd to enable interrupts initially, and the system call vectored path doesn't even need to do that. Thanks, Nick Nicholas Piggin (9): powerpc/64s: syscall real mode entry use mtmsrd rather than rfid powerpc/64s: system call avoid setting MSR[RI] until we set MSR[EE] powerpc/64s: introduce different functions to return from SRR vs HSRR interrupts powerpc/64s: avoid reloading (H)SRR registers if they are still valid powerpc/64: move interrupt return asm to interrupt_64.S powerpc/64s: save one more register in the masked interrupt handler powerpc/64s: allow alternate return locations for soft-masked interrupts powerpc/64s: interrupt soft-enable race fix powerpc/64s: use interrupt restart table to speed up return from interrupt arch/powerpc/Kconfig.debug | 5 + arch/powerpc/include/asm/asm-prototypes.h | 4 +- arch/powerpc/include/asm/head-64.h | 2 +- arch/powerpc/include/asm/interrupt.h | 18 + arch/powerpc/include/asm/paca.h | 3 + arch/powerpc/include/asm/ppc_asm.h | 8 + arch/powerpc/include/asm/ptrace.h | 28 +- arch/powerpc/kernel/asm-offsets.c | 5 + arch/powerpc/kernel/entry_64.S | 508 --------------- arch/powerpc/kernel/exceptions-64s.S | 180 ++++-- arch/powerpc/kernel/fpu.S | 2 + arch/powerpc/kernel/head_64.S | 5 +- arch/powerpc/kernel/interrupt_64.S | 720 +++++++++++++++++++++ arch/powerpc/kernel/irq.c | 79 ++- arch/powerpc/kernel/kgdb.c | 2 +- arch/powerpc/kernel/kprobes-ftrace.c | 2 +- arch/powerpc/kernel/kprobes.c | 10 +- arch/powerpc/kernel/process.c | 21 +- arch/powerpc/kernel/rtas.c | 13 +- arch/powerpc/kernel/signal.c | 2 +- arch/powerpc/kernel/signal_64.c | 14 + arch/powerpc/kernel/syscall_64.c | 242 ++++--- arch/powerpc/kernel/syscalls.c | 2 + arch/powerpc/kernel/traps.c | 18 +- arch/powerpc/kernel/vector.S | 6 +- arch/powerpc/kernel/vmlinux.lds.S | 10 + arch/powerpc/lib/Makefile | 2 +- arch/powerpc/lib/restart_table.c | 26 + arch/powerpc/lib/sstep.c | 5 +- arch/powerpc/math-emu/math.c | 2 +- arch/powerpc/mm/fault.c | 2 +- arch/powerpc/perf/core-book3s.c | 19 +- arch/powerpc/platforms/powernv/opal-call.c | 3 + arch/powerpc/sysdev/fsl_pci.c | 2 +- 34 files changed, 1244 insertions(+), 726 deletions(-) create mode 100644 arch/powerpc/kernel/interrupt_64.S create mode 100644 arch/powerpc/lib/restart_table.c -- 2.23.0