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[3/3] powerpc/pseries: implement nmi ipi with H_SIGNAL_SYS_RESET

Message ID 20161108140125.21455-4-npiggin@gmail.com (mailing list archive)
State Superseded
Headers show

Commit Message

Nicholas Piggin Nov. 8, 2016, 2:01 p.m. UTC 
H_SIGNAL_SYS_RESET can provide a hard NMI (it is not recoverable if
raised when the target has MSR_RI clear).

This patch makes a couple of changes to generic system_reset_exception
handler, which should be split out and platforms defining a handler
audited.
---
 arch/powerpc/kernel/traps.c          |  7 +++++--
 arch/powerpc/platforms/pseries/ras.c |  4 ++++
 arch/powerpc/platforms/pseries/smp.c | 12 +++++++++++-
 3 files changed, 20 insertions(+), 3 deletions(-)

Comments

kernel test robot Nov. 8, 2016, 6:38 p.m. UTC | #1 
Hi Nicholas,

[auto build test ERROR on powerpc/next]
[also build test ERROR on v4.9-rc4]
[cannot apply to next-20161108]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Nicholas-Piggin/powerpc-NMI-IPIs/20161109-005049
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-defconfig (attached as .config)
compiler: powerpc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
reproduce:
        wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        make.cross ARCH=powerpc 

All errors (new ones prefixed by >>):

   arch/powerpc/platforms/pseries/smp.c: In function 'pseries_cause_nmi_ipi':
>> arch/powerpc/platforms/pseries/smp.c:202:7: error: implicit declaration of function 'plapr_signal_sys_reset' [-Werror=implicit-function-declaration]
      if (plapr_signal_sys_reset(cpu) == H_SUCCESS)
          ^~~~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors

vim +/plapr_signal_sys_reset +202 arch/powerpc/platforms/pseries/smp.c

   196			xics_cause_ipi(cpu, data);
   197	}
   198	
   199	static int pseries_cause_nmi_ipi(int cpu, int type)
   200	{
   201		if (type == SMP_OP_NMI_TYPE_HARD) {
 > 202			if (plapr_signal_sys_reset(cpu) == H_SUCCESS)
   203				return 1;
   204		}
   205	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox

Patch

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 023a462..d1d7fd4 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -275,19 +275,22 @@  void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
 
 void system_reset_exception(struct pt_regs *regs)
 {
+	nmi_enter();
+
 	/* See if any machine dependent calls */
 	if (ppc_md.system_reset_exception) {
 		if (ppc_md.system_reset_exception(regs))
-			return;
+			goto done;
 	}
 
 	die("System Reset", regs, SIGABRT);
 
+done:
 	/* Must die if the interrupt is not recoverable */
 	if (!(regs->msr & MSR_RI))
 		panic("Unrecoverable System Reset");
 
-	/* What should we do here? We could issue a shutdown or hard reset. */
+	nmi_exit();
 }
 
 #ifdef CONFIG_PPC64
diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
index 904a677..bb70b26 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -386,6 +386,10 @@  int pSeries_system_reset_exception(struct pt_regs *regs)
 		}
 		fwnmi_release_errinfo();
 	}
+
+	if (smp_handle_nmi_ipi(regs))
+		return 1;
+
 	return 0; /* need to perform reset */
 }
 
diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c
index 0f6522c..4534c5a 100644
--- a/arch/powerpc/platforms/pseries/smp.c
+++ b/arch/powerpc/platforms/pseries/smp.c
@@ -196,6 +196,16 @@  static void pSeries_cause_ipi_mux(int cpu, unsigned long data)
 		xics_cause_ipi(cpu, data);
 }
 
+static int pseries_cause_nmi_ipi(int cpu, int type)
+{
+	if (type == SMP_OP_NMI_TYPE_HARD) {
+		if (plapr_signal_sys_reset(cpu) == H_SUCCESS)
+			return 1;
+	}
+
+	return 0;
+}
+
 static __init void pSeries_smp_probe(void)
 {
 	xics_smp_probe();
@@ -209,7 +219,7 @@  static __init void pSeries_smp_probe(void)
 static struct smp_ops_t pseries_smp_ops = {
 	.message_pass	= NULL,	/* Use smp_muxed_ipi_message_pass */
 	.cause_ipi	= NULL,	/* Filled at runtime by pSeries_smp_probe() */
-	.cause_nmi_ipi	= NULL,
+	.cause_nmi_ipi	= pseries_cause_nmi_ipi,
 	.probe		= pSeries_smp_probe,
 	.kick_cpu	= smp_pSeries_kick_cpu,
 	.setup_cpu	= smp_setup_cpu,