powerpc/xive: Fix dump of XIVE interrupt under pseries

The xmon 'dxi' command calls OPAL to query the XIVE configuration of a
interrupt. This can only be done on baremetal (PowerNV) and it will
crash a pseries machine.

Introduce a new XIVE get_irq_config() operation which implements a
different query depending on the platform, PowerNV or pseries, and
modify xmon to use a top level wrapper.
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190814154754.23682-3-clg@kaod.org

arch/powerpc/include/asm/xive.h

@@ -99,6 +99,8 @@ extern void xive_flush_interrupt(void);
 
 /* xmon hook */
 extern void xmon_xive_do_dump(int cpu);
+extern int xmon_xive_get_irq_config(u32 irq, u32 *target, u8 *prio,
+				    u32 *sw_irq);
 
 /* APIs used by KVM */
 extern u32 xive_native_default_eq_shift(void);

arch/powerpc/sysdev/xive/common.c

@@ -257,6 +257,13 @@ notrace void xmon_xive_do_dump(int cpu)
 	}
 #endif
 }
+
+int xmon_xive_get_irq_config(u32 irq, u32 *target, u8 *prio,
+			     u32 *sw_irq)
+{
+	return xive_ops->get_irq_config(irq, target, prio, sw_irq);
+}
+
 #endif /* CONFIG_XMON */
 
 static unsigned int xive_get_irq(void)

arch/powerpc/sysdev/xive/native.c

@@ -111,6 +111,20 @@ int xive_native_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 sw_irq)
 }
 EXPORT_SYMBOL_GPL(xive_native_configure_irq);
 
+static int xive_native_get_irq_config(u32 hw_irq, u32 *target, u8 *prio,
+				      u32 *sw_irq)
+{
+	s64 rc;
+	__be64 vp;
+	__be32 lirq;
+
+	rc = opal_xive_get_irq_config(hw_irq, &vp, prio, &lirq);
+
+	*target = be64_to_cpu(vp);
+	*sw_irq = be32_to_cpu(lirq);
+
+	return rc == 0 ? 0 : -ENXIO;
+}
 
 /* This can be called multiple time to change a queue configuration */
 int xive_native_configure_queue(u32 vp_id, struct xive_q *q, u8 prio,
@@ -442,6 +456,7 @@ EXPORT_SYMBOL_GPL(xive_native_sync_queue);
 static const struct xive_ops xive_native_ops = {
 	.populate_irq_data	= xive_native_populate_irq_data,
 	.configure_irq		= xive_native_configure_irq,
+	.get_irq_config		= xive_native_get_irq_config,
 	.setup_queue		= xive_native_setup_queue,
 	.cleanup_queue		= xive_native_cleanup_queue,
 	.match			= xive_native_match,

arch/powerpc/sysdev/xive/spapr.c

@@ -215,6 +215,38 @@ static long plpar_int_set_source_config(unsigned long flags,
 	return 0;
 }
 
+static long plpar_int_get_source_config(unsigned long flags,
+					unsigned long lisn,
+					unsigned long *target,
+					unsigned long *prio,
+					unsigned long *sw_irq)
+{
+	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
+	long rc;
+
+	pr_devel("H_INT_GET_SOURCE_CONFIG flags=%lx lisn=%lx\n", flags, lisn);
+
+	do {
+		rc = plpar_hcall(H_INT_GET_SOURCE_CONFIG, retbuf, flags, lisn,
+				 target, prio, sw_irq);
+	} while (plpar_busy_delay(rc));
+
+	if (rc) {
+		pr_err("H_INT_GET_SOURCE_CONFIG lisn=%ld failed %ld\n",
+		       lisn, rc);
+		return rc;
+	}
+
+	*target = retbuf[0];
+	*prio   = retbuf[1];
+	*sw_irq = retbuf[2];
+
+	pr_devel("H_INT_GET_SOURCE_CONFIG target=%lx prio=%lx sw_irq=%lx\n",
+		retbuf[0], retbuf[1], retbuf[2]);
+
+	return 0;
+}
+
 static long plpar_int_get_queue_info(unsigned long flags,
 				     unsigned long target,
 				     unsigned long priority,
@@ -398,6 +430,24 @@ static int xive_spapr_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 sw_irq)
 	return rc == 0 ? 0 : -ENXIO;
 }
 
+static int xive_spapr_get_irq_config(u32 hw_irq, u32 *target, u8 *prio,
+				     u32 *sw_irq)
+{
+	long rc;
+	unsigned long h_target;
+	unsigned long h_prio;
+	unsigned long h_sw_irq;
+
+	rc = plpar_int_get_source_config(0, hw_irq, &h_target, &h_prio,
+					 &h_sw_irq);
+
+	*target = h_target;
+	*prio = h_prio;
+	*sw_irq = h_sw_irq;
+
+	return rc == 0 ? 0 : -ENXIO;
+}
+
 /* This can be called multiple time to change a queue configuration */
 static int xive_spapr_configure_queue(u32 target, struct xive_q *q, u8 prio,
 				   __be32 *qpage, u32 order)
@@ -590,6 +640,7 @@ static void xive_spapr_sync_source(u32 hw_irq)
 static const struct xive_ops xive_spapr_ops = {
 	.populate_irq_data	= xive_spapr_populate_irq_data,
 	.configure_irq		= xive_spapr_configure_irq,
+	.get_irq_config		= xive_spapr_get_irq_config,
 	.setup_queue		= xive_spapr_setup_queue,
 	.cleanup_queue		= xive_spapr_cleanup_queue,
 	.match			= xive_spapr_match,

arch/powerpc/sysdev/xive/xive-internal.h

@@ -33,6 +33,8 @@ struct xive_cpu {
 struct xive_ops {
 	int	(*populate_irq_data)(u32 hw_irq, struct xive_irq_data *data);
 	int 	(*configure_irq)(u32 hw_irq, u32 target, u8 prio, u32 sw_irq);
+	int	(*get_irq_config)(u32 hw_irq, u32 *target, u8 *prio,
+				  u32 *sw_irq);
 	int	(*setup_queue)(unsigned int cpu, struct xive_cpu *xc, u8 prio);
 	void	(*cleanup_queue)(unsigned int cpu, struct xive_cpu *xc, u8 prio);
 	void	(*setup_cpu)(unsigned int cpu, struct xive_cpu *xc);

arch/powerpc/xmon/xmon.c

@@ -2574,14 +2574,14 @@ static void dump_all_xives(void)
 
 static void dump_one_xive_irq(u32 num)
 {
-	s64 rc;
-	__be64 vp;
+	int rc;
+	u32 target;
 	u8 prio;
-	__be32 lirq;
+	u32 lirq;
 
-	rc = opal_xive_get_irq_config(num, &vp, &prio, &lirq);
-	xmon_printf("IRQ 0x%x config: vp=0x%llx prio=%d lirq=0x%x (rc=%lld)\n",
-		    num, be64_to_cpu(vp), prio, be32_to_cpu(lirq), rc);
+	rc = xmon_xive_get_irq_config(num, &target, &prio, &lirq);
+	xmon_printf("IRQ 0x%08x : target=0x%x prio=%d lirq=0x%x (rc=%d)\n",
+		    num, target, prio, lirq, rc);
 }
 
 static void dump_xives(void)