1 files changed, 98 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/mpic_msi.c b/arch/powerpc/sysdev/mpic_msi.c
new file mode 100644
index 000000000..4695c0432
--- /dev/null
+++ b/arch/powerpc/sysdev/mpic_msi.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2006-2007, Michael Ellerman, IBM Corporation.
+ */
+
+#include <linux/irq.h>
+#include <linux/bitmap.h>
+#include <linux/msi.h>
+#include <asm/mpic.h>
+#include <asm/prom.h>
+#include <asm/hw_irq.h>
+#include <asm/ppc-pci.h>
+#include <asm/msi_bitmap.h>
+
+#include <sysdev/mpic.h>
+
+void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
+{
+	/* The mpic calls this even when there is no allocator setup */
+	if (!mpic->msi_bitmap.bitmap)
+		return;
+
+	msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
+}
+
+#ifdef CONFIG_MPIC_U3_HT_IRQS
+static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
+{
+	irq_hw_number_t hwirq;
+	const struct irq_domain_ops *ops = mpic->irqhost->ops;
+	struct device_node *np;
+	int flags, index, i;
+	struct of_phandle_args oirq;
+
+	pr_debug("mpic: found U3, guessing msi allocator setup\n");
+
+	/* Reserve source numbers we know are reserved in the HW.
+	 *
+	 * This is a bit of a mix of U3 and U4 reserves but that's going
+	 * to work fine, we have plenty enugh numbers left so let's just
+	 * mark anything we don't like reserved.
+	 */
+	for (i = 0;   i < 8;   i++)
+		msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
+
+	for (i = 42;  i < 46;  i++)
+		msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
+
+	for (i = 100; i < 105; i++)
+		msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
+
+	for (i = 124; i < mpic->num_sources; i++)
+		msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, i);
+
+
+	np = NULL;
+	while ((np = of_find_all_nodes(np))) {
+		pr_debug("mpic: mapping hwirqs for %pOF\n", np);
+
+		index = 0;
+		while (of_irq_parse_one(np, index++, &oirq) == 0) {
+			ops->xlate(mpic->irqhost, NULL, oirq.args,
+						oirq.args_count, &hwirq, &flags);
+			msi_bitmap_reserve_hwirq(&mpic->msi_bitmap, hwirq);
+		}
+	}
+
+	return 0;
+}
+#else
+static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
+{
+	return -1;
+}
+#endif
+
+int mpic_msi_init_allocator(struct mpic *mpic)
+{
+	int rc;
+
+	rc = msi_bitmap_alloc(&mpic->msi_bitmap, mpic->num_sources,
+			      irq_domain_get_of_node(mpic->irqhost));
+	if (rc)
+		return rc;
+
+	rc = msi_bitmap_reserve_dt_hwirqs(&mpic->msi_bitmap);
+	if (rc > 0) {
+		if (mpic->flags & MPIC_U3_HT_IRQS)
+			rc = mpic_msi_reserve_u3_hwirqs(mpic);
+
+		if (rc) {
+			msi_bitmap_free(&mpic->msi_bitmap);
+			return rc;
+		}
+	}
+
+	return 0;
+}