From a008f8f9fd67ffb13d906ef4ea6235a3d62dfdb6 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Sat, 30 Jan 2021 23:08:41 +1000 Subject: powerpc/64s/hash: improve context tracking of hash faults This moves the 64s/hash context tracking from hash_page_mm() to __do_hash_fault(), so it's no longer called by OCXL / SPU accelerators, which was certainly the wrong thing to be doing, because those callers are not low level interrupt handlers, so should have entered a kernel context tracking already. Then remain in kernel context for the duration of the fault, rather than enter/exit for the hash fault then enter/exit for the page fault, which is pointless. Even still, calling exception_enter/exit in __do_hash_fault seems questionable because that's touching per-cpu variables, tracing, etc., which might have been interrupted by this hash fault or themselves cause hash faults. But maybe I miss something because hash_page_mm very deliberately calls trace_hash_fault too, for example. So for now go with it, it's no worse than before, in this regard. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20210130130852.2952424-32-npiggin@gmail.com --- arch/powerpc/include/asm/bug.h | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/powerpc/include/asm/bug.h') diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h index c10ae0a9bbaf..d1635ffbb179 100644 --- a/arch/powerpc/include/asm/bug.h +++ b/arch/powerpc/include/asm/bug.h @@ -112,6 +112,7 @@ struct pt_regs; long do_page_fault(struct pt_regs *); +long hash__do_page_fault(struct pt_regs *); void bad_page_fault(struct pt_regs *, int); void __bad_page_fault(struct pt_regs *regs, int sig); void do_bad_page_fault_segv(struct pt_regs *regs); -- cgit