[PATCH 4/4] powerpc/xive: Add a debugfs file to dump internal XIVE state
Cédric Le Goater
clg at kaod.org
Sat Mar 7 02:01:43 AEDT 2020
As does XMON, the debugfs file /sys/kernel/debug/powerpc/xive exposes
the XIVE internal state of the machine CPUs and interrupts. Available
on the PowerNV and sPAPR platforms.
Signed-off-by: Cédric Le Goater <clg at kaod.org>
---
arch/powerpc/sysdev/xive/xive-internal.h | 2 +
arch/powerpc/sysdev/xive/common.c | 105 +++++++++++++++++++++++
arch/powerpc/sysdev/xive/native.c | 3 +
arch/powerpc/sysdev/xive/spapr.c | 19 ++++
4 files changed, 129 insertions(+)
diff --git a/arch/powerpc/sysdev/xive/xive-internal.h b/arch/powerpc/sysdev/xive/xive-internal.h
index 382980f4de2d..b7b901da2168 100644
--- a/arch/powerpc/sysdev/xive/xive-internal.h
+++ b/arch/powerpc/sysdev/xive/xive-internal.h
@@ -57,12 +57,14 @@ struct xive_ops {
int (*get_ipi)(unsigned int cpu, struct xive_cpu *xc);
void (*put_ipi)(unsigned int cpu, struct xive_cpu *xc);
#endif
+ int (*debug_show)(struct seq_file *m, void *private);
const char *name;
};
bool xive_core_init(const struct xive_ops *ops, void __iomem *area, u32 offset,
u8 max_prio);
__be32 *xive_queue_page_alloc(unsigned int cpu, u32 queue_shift);
+int xive_core_debug_init(void);
static inline u32 xive_alloc_order(u32 queue_shift)
{
diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index c865ae554605..e192077481a1 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -20,6 +20,7 @@
#include <linux/spinlock.h>
#include <linux/msi.h>
+#include <asm/debugfs.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/smp.h>
@@ -1558,3 +1559,107 @@ static int __init xive_off(char *arg)
return 0;
}
__setup("xive=off", xive_off);
+
+void xive_debug_show_cpu(struct seq_file *m, int cpu)
+{
+ struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
+
+ seq_printf(m, "CPU %d:", cpu);
+ if (xc) {
+ seq_printf(m, "pp=%02x CPPR=%02x ", xc->pending_prio, xc->cppr);
+
+#ifdef CONFIG_SMP
+ {
+ u64 val = xive_esb_read(&xc->ipi_data, XIVE_ESB_GET);
+
+ seq_printf(m, "IPI=0x%08x PQ=%c%c ", xc->hw_ipi,
+ val & XIVE_ESB_VAL_P ? 'P' : '-',
+ val & XIVE_ESB_VAL_Q ? 'Q' : '-');
+ }
+#endif
+ {
+ struct xive_q *q = &xc->queue[xive_irq_priority];
+ u32 i0, i1, idx;
+
+ if (q->qpage) {
+ idx = q->idx;
+ i0 = be32_to_cpup(q->qpage + idx);
+ idx = (idx + 1) & q->msk;
+ i1 = be32_to_cpup(q->qpage + idx);
+ seq_printf(m, "EQ idx=%d T=%d %08x %08x ...",
+ q->idx, q->toggle, i0, i1);
+ }
+ }
+ }
+ seq_puts(m, "\n");
+}
+
+void xive_debug_show_irq(struct seq_file *m, u32 hw_irq, struct irq_data *d)
+{
+ struct irq_chip *chip = irq_data_get_irq_chip(d);
+ int rc;
+ u32 target;
+ u8 prio;
+ u32 lirq;
+
+ if (!is_xive_irq(chip))
+ return;
+
+ rc = xive_ops->get_irq_config(hw_irq, &target, &prio, &lirq);
+ if (rc) {
+ seq_printf(m, "IRQ 0x%08x : no config rc=%d\n", hw_irq, rc);
+ return;
+ }
+
+ seq_printf(m, "IRQ 0x%08x : target=0x%x prio=%02x lirq=0x%x ",
+ hw_irq, target, prio, lirq);
+
+ if (d) {
+ struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+ u64 val = xive_esb_read(xd, XIVE_ESB_GET);
+
+ seq_printf(m, "flags=%c%c%c PQ=%c%c",
+ xd->flags & XIVE_IRQ_FLAG_STORE_EOI ? 'S' : ' ',
+ xd->flags & XIVE_IRQ_FLAG_LSI ? 'L' : ' ',
+ xd->flags & XIVE_IRQ_FLAG_H_INT_ESB ? 'H' : ' ',
+ val & XIVE_ESB_VAL_P ? 'P' : '-',
+ val & XIVE_ESB_VAL_Q ? 'Q' : '-');
+ }
+ seq_puts(m, "\n");
+}
+
+static int xive_core_debug_show(struct seq_file *m, void *private)
+{
+ unsigned int i;
+ struct irq_desc *desc;
+ int cpu;
+
+ if (xive_ops->debug_show)
+ xive_ops->debug_show(m, private);
+
+ for_each_possible_cpu(cpu)
+ xive_debug_show_cpu(m, cpu);
+
+ for_each_irq_desc(i, desc) {
+ struct irq_data *d = irq_desc_get_irq_data(desc);
+ unsigned int hw_irq;
+
+ if (!d)
+ continue;
+
+ hw_irq = (unsigned int)irqd_to_hwirq(d);
+
+ /* IPIs are special (HW number 0) */
+ if (hw_irq)
+ xive_debug_show_irq(m, hw_irq, d);
+ }
+ return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(xive_core_debug);
+
+int xive_core_debug_init(void)
+{
+ debugfs_create_file("xive", 0444, powerpc_debugfs_root,
+ NULL, &xive_core_debug_fops);
+ return 0;
+}
diff --git a/arch/powerpc/sysdev/xive/native.c b/arch/powerpc/sysdev/xive/native.c
index 50e1a8e02497..5218fdc4b29a 100644
--- a/arch/powerpc/sysdev/xive/native.c
+++ b/arch/powerpc/sysdev/xive/native.c
@@ -19,6 +19,7 @@
#include <linux/cpumask.h>
#include <linux/mm.h>
+#include <asm/machdep.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/smp.h>
@@ -850,3 +851,5 @@ int xive_native_get_vp_state(u32 vp_id, u64 *out_state)
return 0;
}
EXPORT_SYMBOL_GPL(xive_native_get_vp_state);
+
+machine_arch_initcall(powernv, xive_core_debug_init);
diff --git a/arch/powerpc/sysdev/xive/spapr.c b/arch/powerpc/sysdev/xive/spapr.c
index 3f15615712b5..7ab5c6780997 100644
--- a/arch/powerpc/sysdev/xive/spapr.c
+++ b/arch/powerpc/sysdev/xive/spapr.c
@@ -18,6 +18,7 @@
#include <linux/delay.h>
#include <linux/libfdt.h>
+#include <asm/machdep.h>
#include <asm/prom.h>
#include <asm/io.h>
#include <asm/smp.h>
@@ -645,6 +646,21 @@ static void xive_spapr_sync_source(u32 hw_irq)
plpar_int_sync(0, hw_irq);
}
+static int xive_spapr_debug_show(struct seq_file *m, void *private)
+{
+ struct xive_irq_bitmap *xibm;
+ char *buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
+
+ list_for_each_entry(xibm, &xive_irq_bitmaps, list) {
+ memset(buf, 0, PAGE_SIZE);
+ bitmap_print_to_pagebuf(true, buf, xibm->bitmap, xibm->count);
+ seq_printf(m, "bitmap #%d: %s", xibm->count, buf);
+ }
+ kfree(buf);
+
+ return 0;
+}
+
static const struct xive_ops xive_spapr_ops = {
.populate_irq_data = xive_spapr_populate_irq_data,
.configure_irq = xive_spapr_configure_irq,
@@ -662,6 +678,7 @@ static const struct xive_ops xive_spapr_ops = {
#ifdef CONFIG_SMP
.get_ipi = xive_spapr_get_ipi,
.put_ipi = xive_spapr_put_ipi,
+ .debug_show = xive_spapr_debug_show,
#endif /* CONFIG_SMP */
.name = "spapr",
};
@@ -839,3 +856,5 @@ bool __init xive_spapr_init(void)
pr_info("Using %dkB queues\n", 1 << (xive_queue_shift - 10));
return true;
}
+
+machine_arch_initcall(pseries, xive_core_debug_init);
--
2.21.1
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