Le 05/09/2020 à 19:43, Nicholas Piggin a écrit :
Make interrupt handlers all just take the pt_regs * argument and load
DAR/DSISR etc from that. Make those that return a value return long.
I like this, it will likely simplify a bit the VMAP_STACK mess.
Not sure it is that easy. My board is stuck after the start of init.
On the 8xx, on Instruction TLB Error exception, we do
andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
On book3s/32, on ISI exception we do:
andis. r5,r9,DSISR_SRR1_MATCH_32S@h /* Filter relevant SRR1 bits */
On 40x and bookE, on ISI exception we do:
li r5,0 /* Pass zero as arg3 */
And regs->dsisr will just contain nothing
So it means we should at least write back r5 into regs->dsisr from there
? The performance impact should be minimal as we already write _DAR so
the cache line should already be in the cache.
A hacky 'stw r5, _DSISR(r1)' in handle_page_fault() does the trick,
allthough we don't want to do it for both ISI and DSI at the end, so
you'll have to do it in every head_xxx.S
While you are at it, it would probably also make sense to do remove the
address param of bad_page_fault(), there is no point in loading back
regs->dar in handle_page_fault() and machine_check_8xx() and
alignment_exception(), just read regs->dar in bad_page_fault()
The case of do_break() should also be looked at.
Why changing return code from int to long ?
Christophe
This is done to make the function signatures match more closely, which
will help with a future patch to add wrappers. Explicit arguments could
be re-added for performance in future but that would require more
complex wrapper macros.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/include/asm/asm-prototypes.h | 4 ++--
arch/powerpc/include/asm/bug.h | 4 ++--
arch/powerpc/kernel/exceptions-64e.S | 2 --
arch/powerpc/kernel/exceptions-64s.S | 14 ++------------
arch/powerpc/mm/book3s64/hash_utils.c | 8 +++++---
arch/powerpc/mm/book3s64/slb.c | 11 +++++++----
arch/powerpc/mm/fault.c | 16 +++++++++-------
7 files changed, 27 insertions(+), 32 deletions(-)
diff --git a/arch/powerpc/include/asm/bug.h b/arch/powerpc/include/asm/bug.h
index d714d83bbc7c..2fa0cf6c6011 100644
--- a/arch/powerpc/include/asm/bug.h
+++ b/arch/powerpc/include/asm/bug.h
@@ -111,8 +111,8 @@
#ifndef __ASSEMBLY__
struct pt_regs;
-extern int do_page_fault(struct pt_regs *, unsigned long, unsigned long);
-extern int hash__do_page_fault(struct pt_regs *, unsigned long, unsigned long);
+extern long do_page_fault(struct pt_regs *);
+extern long hash__do_page_fault(struct pt_regs *);
no extern
extern void bad_page_fault(struct pt_regs *, unsigned long, int);
extern void _exception(int, struct pt_regs *, int, unsigned long);
extern void _exception_pkey(struct pt_regs *, unsigned long, int);
Christophe
