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From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>,
	Ganesh Goudar <ganeshgr@linux.ibm.com>,
	Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH 4/7] powerpc/64s: machine check reconcile irq state
Date: Tue, 17 Mar 2020 19:09:10 +1000	[thread overview]
Message-ID: <20200317090913.343097-5-npiggin@gmail.com> (raw)
In-Reply-To: <20200317090913.343097-1-npiggin@gmail.com>

pseries fwnmi machine check code pops the soft-irq checks in rtas_call
(after the previous 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>
---
 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 d95c4560c038..31bdbb94e477 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1186,11 +1186,30 @@ 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
-- 
2.23.0


  parent reply	other threads:[~2020-03-17  9:18 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-03-17  9:09 [PATCH 0/7] powerpc/64: machine check and other RAS fixes Nicholas Piggin
2020-03-17  9:09 ` [PATCH 1/7] powerpc/64: mark emergency stacks valid to unwind Nicholas Piggin
2020-03-17  9:09 ` [PATCH 2/7] powerpc/pseries/ras: avoid calling rtas_token in NMI paths Nicholas Piggin
2020-03-17  9:09 ` [PATCH 3/7] powerpc/64s: Change irq reconcile for NMIs from reusing _DAR to RESULT Nicholas Piggin
2020-03-17  9:09 ` Nicholas Piggin [this message]
2020-03-17  9:09 ` [PATCH 5/7] powerpc/pseries/ras: FWNMI_VALID off by one Nicholas Piggin
2020-03-17  9:09 ` [PATCH 6/7] powerpc/pseries/ras: fwnmi avoid modifying r3 in error case Nicholas Piggin
2020-03-17  9:09 ` [PATCH 7/7] powerpc/pseries/ras: fwnmi sreset should not interlock Nicholas Piggin

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