powerpc/xive: Add a debug_show handler to the XIVE irq_domain

Full state of the Linux interrupt descriptors can be dumped under
debugfs when compiled with CONFIG_GENERIC_IRQ_DEBUGFS. Add support for
the XIVE interrupt controller.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201210171450.1933725-7-clg@kaod.org

diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index 8b1fe72..61a5f08 100644 (file)
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -1303,11 +1303,69 @@ static int xive_irq_domain_match(struct irq_domain *h, struct device_node *node,
        return xive_ops->match(node);
 }
 
+#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
+static const char * const esb_names[] = { "RESET", "OFF", "PENDING", "QUEUED" };
+
+static const struct {
+       u64  mask;
+       char *name;
+} xive_irq_flags[] = {
+       { XIVE_IRQ_FLAG_STORE_EOI, "STORE_EOI" },
+       { XIVE_IRQ_FLAG_LSI,       "LSI"       },
+       { XIVE_IRQ_FLAG_SHIFT_BUG, "SHIFT_BUG" },
+       { XIVE_IRQ_FLAG_MASK_FW,   "MASK_FW"   },
+       { XIVE_IRQ_FLAG_EOI_FW,    "EOI_FW"    },
+       { XIVE_IRQ_FLAG_H_INT_ESB, "H_INT_ESB" },
+       { XIVE_IRQ_FLAG_NO_EOI,    "NO_EOI"    },
+};
+
+static void xive_irq_domain_debug_show(struct seq_file *m, struct irq_domain *d,
+                                      struct irq_data *irqd, int ind)
+{
+       struct xive_irq_data *xd;
+       u64 val;
+       int i;
+
+       /* No IRQ domain level information. To be done */
+       if (!irqd)
+               return;
+
+       if (!is_xive_irq(irq_data_get_irq_chip(irqd)))
+               return;
+
+       seq_printf(m, "%*sXIVE:\n", ind, "");
+       ind++;
+
+       xd = irq_data_get_irq_handler_data(irqd);
+       if (!xd) {
+               seq_printf(m, "%*snot assigned\n", ind, "");
+               return;
+       }
+
+       val = xive_esb_read(xd, XIVE_ESB_GET);
+       seq_printf(m, "%*sESB:      %s\n", ind, "", esb_names[val & 0x3]);
+       seq_printf(m, "%*sPstate:   %s %s\n", ind, "", xd->stale_p ? "stale" : "",
+                  xd->saved_p ? "saved" : "");
+       seq_printf(m, "%*sTarget:   %d\n", ind, "", xd->target);
+       seq_printf(m, "%*sChip:     %d\n", ind, "", xd->src_chip);
+       seq_printf(m, "%*sTrigger:  0x%016llx\n", ind, "", xd->trig_page);
+       seq_printf(m, "%*sEOI:      0x%016llx\n", ind, "", xd->eoi_page);
+       seq_printf(m, "%*sFlags:    0x%llx\n", ind, "", xd->flags);
+       for (i = 0; i < ARRAY_SIZE(xive_irq_flags); i++) {
+               if (xd->flags & xive_irq_flags[i].mask)
+                       seq_printf(m, "%*s%s\n", ind + 12, "", xive_irq_flags[i].name);
+       }
+}
+#endif
+
 static const struct irq_domain_ops xive_irq_domain_ops = {
        .match = xive_irq_domain_match,
        .map = xive_irq_domain_map,
        .unmap = xive_irq_domain_unmap,
        .xlate = xive_irq_domain_xlate,
+#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
+       .debug_show = xive_irq_domain_debug_show,
+#endif
 };
 
 static void __init xive_init_host(struct device_node *np)