From: Nicholas Piggin npiggin@gmail.com
[ Upstream commit f0fd9dd3c213c947dfb5bc2cad3ef5e30d3258ec ]
pseries fwnmi machine check code pops the soft-irq checks in rtas_call (after the next patch to remove rtas_token from this call path). Rather than play whack a mole with these and forever having fragile code, it seems better to have the early machine check handler perform the same kind of reconcile as the other NMI interrupts.
WARNING: CPU: 0 PID: 493 at arch/powerpc/kernel/irq.c:343 CPU: 0 PID: 493 Comm: a Tainted: G W NIP: c00000000001ed2c LR: c000000000042c40 CTR: 0000000000000000 REGS: c0000001fffd38b0 TRAP: 0700 Tainted: G W MSR: 8000000000021003 <SF,ME,RI,LE> CR: 28000488 XER: 00000000 CFAR: c00000000001ec90 IRQMASK: 0 GPR00: c000000000043820 c0000001fffd3b40 c0000000012ba300 0000000000000000 GPR04: 0000000048000488 0000000000000000 0000000000000000 00000000deadbeef GPR08: 0000000000000080 0000000000000000 0000000000000000 0000000000001001 GPR12: 0000000000000000 c0000000014a0000 0000000000000000 0000000000000000 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR24: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR28: 0000000000000000 0000000000000001 c000000001360810 0000000000000000 NIP [c00000000001ed2c] arch_local_irq_restore.part.0+0xac/0x100 LR [c000000000042c40] unlock_rtas+0x30/0x90 Call Trace: [c0000001fffd3b40] [c000000001360810] 0xc000000001360810 (unreliable) [c0000001fffd3b60] [c000000000043820] rtas_call+0x1c0/0x280 [c0000001fffd3bb0] [c0000000000dc328] fwnmi_release_errinfo+0x38/0x70 [c0000001fffd3c10] [c0000000000dcd8c] pseries_machine_check_realmode+0x1dc/0x540 [c0000001fffd3cd0] [c00000000003fe04] machine_check_early+0x54/0x70 [c0000001fffd3d00] [c000000000008384] machine_check_early_common+0x134/0x1f0 --- interrupt: 200 at 0x13f1307c8 LR = 0x7fff888b8528 Instruction dump: 60000000 7d2000a6 71298000 41820068 39200002 7d210164 4bffff9c 60000000 60000000 7d2000a6 71298000 4c820020 <0fe00000> 4e800020 60000000 60000000
Signed-off-by: Nicholas Piggin npiggin@gmail.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20200508043408.886394-5-npiggin@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kernel/exceptions-64s.S | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+)
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 463372046169..d3e19934cca9 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -1117,11 +1117,30 @@ END_FTR_SECTION_IFSET(CPU_FTR_HVMODE) li r10,MSR_RI mtmsrd r10,1
+ /* + * Set IRQS_ALL_DISABLED and save PACAIRQHAPPENED (see + * system_reset_common) + */ + li r10,IRQS_ALL_DISABLED + stb r10,PACAIRQSOFTMASK(r13) + lbz r10,PACAIRQHAPPENED(r13) + std r10,RESULT(r1) + ori r10,r10,PACA_IRQ_HARD_DIS + stb r10,PACAIRQHAPPENED(r13) + addi r3,r1,STACK_FRAME_OVERHEAD bl machine_check_early std r3,RESULT(r1) /* Save result */ ld r12,_MSR(r1)
+ /* + * Restore soft mask settings. + */ + ld r10,RESULT(r1) + stb r10,PACAIRQHAPPENED(r13) + ld r10,SOFTE(r1) + stb r10,PACAIRQSOFTMASK(r13) + #ifdef CONFIG_PPC_P7_NAP /* * Check if thread was in power saving mode. We come here when any