Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1864 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
new file mode 100644
index 000000000..a289cb97c
--- /dev/null
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -0,0 +1,1864 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2016,2017 IBM Corporation.
+ */
+
+#define pr_fmt(fmt) "xive: " fmt
+
+#include <linux/types.h>
+#include <linux/threads.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
+#include <linux/debugfs.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/msi.h>
+#include <linux/vmalloc.h>
+
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+#include <asm/irq.h>
+#include <asm/errno.h>
+#include <asm/xive.h>
+#include <asm/xive-regs.h>
+#include <asm/xmon.h>
+
+#include "xive-internal.h"
+
+#undef DEBUG_FLUSH
+#undef DEBUG_ALL
+
+#ifdef DEBUG_ALL
+#define DBG_VERBOSE(fmt, ...)	pr_devel("cpu %d - " fmt, \
+					 smp_processor_id(), ## __VA_ARGS__)
+#else
+#define DBG_VERBOSE(fmt...)	do { } while(0)
+#endif
+
+bool __xive_enabled;
+EXPORT_SYMBOL_GPL(__xive_enabled);
+bool xive_cmdline_disabled;
+
+/* We use only one priority for now */
+static u8 xive_irq_priority;
+
+/* TIMA exported to KVM */
+void __iomem *xive_tima;
+EXPORT_SYMBOL_GPL(xive_tima);
+u32 xive_tima_offset;
+
+/* Backend ops */
+static const struct xive_ops *xive_ops;
+
+/* Our global interrupt domain */
+static struct irq_domain *xive_irq_domain;
+
+#ifdef CONFIG_SMP
+/* The IPIs use the same logical irq number when on the same chip */
+static struct xive_ipi_desc {
+	unsigned int irq;
+	char name[16];
+	atomic_t started;
+} *xive_ipis;
+
+/*
+ * Use early_cpu_to_node() for hot-plugged CPUs
+ */
+static unsigned int xive_ipi_cpu_to_irq(unsigned int cpu)
+{
+	return xive_ipis[early_cpu_to_node(cpu)].irq;
+}
+#endif
+
+/* Xive state for each CPU */
+static DEFINE_PER_CPU(struct xive_cpu *, xive_cpu);
+
+/* An invalid CPU target */
+#define XIVE_INVALID_TARGET	(-1)
+
+/*
+ * Global toggle to switch on/off StoreEOI
+ */
+static bool xive_store_eoi = true;
+
+static bool xive_is_store_eoi(struct xive_irq_data *xd)
+{
+	return xd->flags & XIVE_IRQ_FLAG_STORE_EOI && xive_store_eoi;
+}
+
+/*
+ * Read the next entry in a queue, return its content if it's valid
+ * or 0 if there is no new entry.
+ *
+ * The queue pointer is moved forward unless "just_peek" is set
+ */
+static u32 xive_read_eq(struct xive_q *q, bool just_peek)
+{
+	u32 cur;
+
+	if (!q->qpage)
+		return 0;
+	cur = be32_to_cpup(q->qpage + q->idx);
+
+	/* Check valid bit (31) vs current toggle polarity */
+	if ((cur >> 31) == q->toggle)
+		return 0;
+
+	/* If consuming from the queue ... */
+	if (!just_peek) {
+		/* Next entry */
+		q->idx = (q->idx + 1) & q->msk;
+
+		/* Wrap around: flip valid toggle */
+		if (q->idx == 0)
+			q->toggle ^= 1;
+	}
+	/* Mask out the valid bit (31) */
+	return cur & 0x7fffffff;
+}
+
+/*
+ * Scans all the queue that may have interrupts in them
+ * (based on "pending_prio") in priority order until an
+ * interrupt is found or all the queues are empty.
+ *
+ * Then updates the CPPR (Current Processor Priority
+ * Register) based on the most favored interrupt found
+ * (0xff if none) and return what was found (0 if none).
+ *
+ * If just_peek is set, return the most favored pending
+ * interrupt if any but don't update the queue pointers.
+ *
+ * Note: This function can operate generically on any number
+ * of queues (up to 8). The current implementation of the XIVE
+ * driver only uses a single queue however.
+ *
+ * Note2: This will also "flush" "the pending_count" of a queue
+ * into the "count" when that queue is observed to be empty.
+ * This is used to keep track of the amount of interrupts
+ * targetting a queue. When an interrupt is moved away from
+ * a queue, we only decrement that queue count once the queue
+ * has been observed empty to avoid races.
+ */
+static u32 xive_scan_interrupts(struct xive_cpu *xc, bool just_peek)
+{
+	u32 irq = 0;
+	u8 prio = 0;
+
+	/* Find highest pending priority */
+	while (xc->pending_prio != 0) {
+		struct xive_q *q;
+
+		prio = ffs(xc->pending_prio) - 1;
+		DBG_VERBOSE("scan_irq: trying prio %d\n", prio);
+
+		/* Try to fetch */
+		irq = xive_read_eq(&xc->queue[prio], just_peek);
+
+		/* Found something ? That's it */
+		if (irq) {
+			if (just_peek || irq_to_desc(irq))
+				break;
+			/*
+			 * We should never get here; if we do then we must
+			 * have failed to synchronize the interrupt properly
+			 * when shutting it down.
+			 */
+			pr_crit("xive: got interrupt %d without descriptor, dropping\n",
+				irq);
+			WARN_ON(1);
+			continue;
+		}
+
+		/* Clear pending bits */
+		xc->pending_prio &= ~(1 << prio);
+
+		/*
+		 * Check if the queue count needs adjusting due to
+		 * interrupts being moved away. See description of
+		 * xive_dec_target_count()
+		 */
+		q = &xc->queue[prio];
+		if (atomic_read(&q->pending_count)) {
+			int p = atomic_xchg(&q->pending_count, 0);
+			if (p) {
+				WARN_ON(p > atomic_read(&q->count));
+				atomic_sub(p, &q->count);
+			}
+		}
+	}
+
+	/* If nothing was found, set CPPR to 0xff */
+	if (irq == 0)
+		prio = 0xff;
+
+	/* Update HW CPPR to match if necessary */
+	if (prio != xc->cppr) {
+		DBG_VERBOSE("scan_irq: adjusting CPPR to %d\n", prio);
+		xc->cppr = prio;
+		out_8(xive_tima + xive_tima_offset + TM_CPPR, prio);
+	}
+
+	return irq;
+}
+
+/*
+ * This is used to perform the magic loads from an ESB
+ * described in xive-regs.h
+ */
+static notrace u8 xive_esb_read(struct xive_irq_data *xd, u32 offset)
+{
+	u64 val;
+
+	if (offset == XIVE_ESB_SET_PQ_10 && xive_is_store_eoi(xd))
+		offset |= XIVE_ESB_LD_ST_MO;
+
+	if ((xd->flags & XIVE_IRQ_FLAG_H_INT_ESB) && xive_ops->esb_rw)
+		val = xive_ops->esb_rw(xd->hw_irq, offset, 0, 0);
+	else
+		val = in_be64(xd->eoi_mmio + offset);
+
+	return (u8)val;
+}
+
+static void xive_esb_write(struct xive_irq_data *xd, u32 offset, u64 data)
+{
+	if ((xd->flags & XIVE_IRQ_FLAG_H_INT_ESB) && xive_ops->esb_rw)
+		xive_ops->esb_rw(xd->hw_irq, offset, data, 1);
+	else
+		out_be64(xd->eoi_mmio + offset, data);
+}
+
+#if defined(CONFIG_XMON) || defined(CONFIG_DEBUG_FS)
+static void xive_irq_data_dump(struct xive_irq_data *xd, char *buffer, size_t size)
+{
+	u64 val = xive_esb_read(xd, XIVE_ESB_GET);
+
+	snprintf(buffer, size, "flags=%c%c%c PQ=%c%c 0x%016llx 0x%016llx",
+		 xive_is_store_eoi(xd) ? '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' : '-',
+		 xd->trig_page, xd->eoi_page);
+}
+#endif
+
+#ifdef CONFIG_XMON
+static notrace void xive_dump_eq(const char *name, struct xive_q *q)
+{
+	u32 i0, i1, idx;
+
+	if (!q->qpage)
+		return;
+	idx = q->idx;
+	i0 = be32_to_cpup(q->qpage + idx);
+	idx = (idx + 1) & q->msk;
+	i1 = be32_to_cpup(q->qpage + idx);
+	xmon_printf("%s idx=%d T=%d %08x %08x ...", name,
+		     q->idx, q->toggle, i0, i1);
+}
+
+notrace void xmon_xive_do_dump(int cpu)
+{
+	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
+
+	xmon_printf("CPU %d:", cpu);
+	if (xc) {
+		xmon_printf("pp=%02x CPPR=%02x ", xc->pending_prio, xc->cppr);
+
+#ifdef CONFIG_SMP
+		{
+			char buffer[128];
+
+			xive_irq_data_dump(&xc->ipi_data, buffer, sizeof(buffer));
+			xmon_printf("IPI=0x%08x %s", xc->hw_ipi, buffer);
+		}
+#endif
+		xive_dump_eq("EQ", &xc->queue[xive_irq_priority]);
+	}
+	xmon_printf("\n");
+}
+
+static struct irq_data *xive_get_irq_data(u32 hw_irq)
+{
+	unsigned int irq = irq_find_mapping(xive_irq_domain, hw_irq);
+
+	return irq ? irq_get_irq_data(irq) : NULL;
+}
+
+int xmon_xive_get_irq_config(u32 hw_irq, struct irq_data *d)
+{
+	int rc;
+	u32 target;
+	u8 prio;
+	u32 lirq;
+
+	rc = xive_ops->get_irq_config(hw_irq, &target, &prio, &lirq);
+	if (rc) {
+		xmon_printf("IRQ 0x%08x : no config rc=%d\n", hw_irq, rc);
+		return rc;
+	}
+
+	xmon_printf("IRQ 0x%08x : target=0x%x prio=%02x lirq=0x%x ",
+		    hw_irq, target, prio, lirq);
+
+	if (!d)
+		d = xive_get_irq_data(hw_irq);
+
+	if (d) {
+		char buffer[128];
+
+		xive_irq_data_dump(irq_data_get_irq_handler_data(d),
+				   buffer, sizeof(buffer));
+		xmon_printf("%s", buffer);
+	}
+
+	xmon_printf("\n");
+	return 0;
+}
+
+void xmon_xive_get_irq_all(void)
+{
+	unsigned int i;
+	struct irq_desc *desc;
+
+	for_each_irq_desc(i, desc) {
+		struct irq_data *d = irq_domain_get_irq_data(xive_irq_domain, i);
+
+		if (d)
+			xmon_xive_get_irq_config(irqd_to_hwirq(d), d);
+	}
+}
+
+#endif /* CONFIG_XMON */
+
+static unsigned int xive_get_irq(void)
+{
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+	u32 irq;
+
+	/*
+	 * This can be called either as a result of a HW interrupt or
+	 * as a "replay" because EOI decided there was still something
+	 * in one of the queues.
+	 *
+	 * First we perform an ACK cycle in order to update our mask
+	 * of pending priorities. This will also have the effect of
+	 * updating the CPPR to the most favored pending interrupts.
+	 *
+	 * In the future, if we have a way to differentiate a first
+	 * entry (on HW interrupt) from a replay triggered by EOI,
+	 * we could skip this on replays unless we soft-mask tells us
+	 * that a new HW interrupt occurred.
+	 */
+	xive_ops->update_pending(xc);
+
+	DBG_VERBOSE("get_irq: pending=%02x\n", xc->pending_prio);
+
+	/* Scan our queue(s) for interrupts */
+	irq = xive_scan_interrupts(xc, false);
+
+	DBG_VERBOSE("get_irq: got irq 0x%x, new pending=0x%02x\n",
+	    irq, xc->pending_prio);
+
+	/* Return pending interrupt if any */
+	if (irq == XIVE_BAD_IRQ)
+		return 0;
+	return irq;
+}
+
+/*
+ * After EOI'ing an interrupt, we need to re-check the queue
+ * to see if another interrupt is pending since multiple
+ * interrupts can coalesce into a single notification to the
+ * CPU.
+ *
+ * If we find that there is indeed more in there, we call
+ * force_external_irq_replay() to make Linux synthetize an
+ * external interrupt on the next call to local_irq_restore().
+ */
+static void xive_do_queue_eoi(struct xive_cpu *xc)
+{
+	if (xive_scan_interrupts(xc, true) != 0) {
+		DBG_VERBOSE("eoi: pending=0x%02x\n", xc->pending_prio);
+		force_external_irq_replay();
+	}
+}
+
+/*
+ * EOI an interrupt at the source. There are several methods
+ * to do this depending on the HW version and source type
+ */
+static void xive_do_source_eoi(struct xive_irq_data *xd)
+{
+	u8 eoi_val;
+
+	xd->stale_p = false;
+
+	/* If the XIVE supports the new "store EOI facility, use it */
+	if (xive_is_store_eoi(xd)) {
+		xive_esb_write(xd, XIVE_ESB_STORE_EOI, 0);
+		return;
+	}
+
+	/*
+	 * For LSIs, we use the "EOI cycle" special load rather than
+	 * PQ bits, as they are automatically re-triggered in HW when
+	 * still pending.
+	 */
+	if (xd->flags & XIVE_IRQ_FLAG_LSI) {
+		xive_esb_read(xd, XIVE_ESB_LOAD_EOI);
+		return;
+	}
+
+	/*
+	 * Otherwise, we use the special MMIO that does a clear of
+	 * both P and Q and returns the old Q. This allows us to then
+	 * do a re-trigger if Q was set rather than synthesizing an
+	 * interrupt in software
+	 */
+	eoi_val = xive_esb_read(xd, XIVE_ESB_SET_PQ_00);
+	DBG_VERBOSE("eoi_val=%x\n", eoi_val);
+
+	/* Re-trigger if needed */
+	if ((eoi_val & XIVE_ESB_VAL_Q) && xd->trig_mmio)
+		out_be64(xd->trig_mmio, 0);
+}
+
+/* irq_chip eoi callback, called with irq descriptor lock held */
+static void xive_irq_eoi(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+
+	DBG_VERBOSE("eoi_irq: irq=%d [0x%lx] pending=%02x\n",
+		    d->irq, irqd_to_hwirq(d), xc->pending_prio);
+
+	/*
+	 * EOI the source if it hasn't been disabled and hasn't
+	 * been passed-through to a KVM guest
+	 */
+	if (!irqd_irq_disabled(d) && !irqd_is_forwarded_to_vcpu(d) &&
+	    !(xd->flags & XIVE_IRQ_FLAG_NO_EOI))
+		xive_do_source_eoi(xd);
+	else
+		xd->stale_p = true;
+
+	/*
+	 * Clear saved_p to indicate that it's no longer occupying
+	 * a queue slot on the target queue
+	 */
+	xd->saved_p = false;
+
+	/* Check for more work in the queue */
+	xive_do_queue_eoi(xc);
+}
+
+/*
+ * Helper used to mask and unmask an interrupt source.
+ */
+static void xive_do_source_set_mask(struct xive_irq_data *xd,
+				    bool mask)
+{
+	u64 val;
+
+	pr_debug("%s: HW 0x%x %smask\n", __func__, xd->hw_irq, mask ? "" : "un");
+
+	/*
+	 * If the interrupt had P set, it may be in a queue.
+	 *
+	 * We need to make sure we don't re-enable it until it
+	 * has been fetched from that queue and EOId. We keep
+	 * a copy of that P state and use it to restore the
+	 * ESB accordingly on unmask.
+	 */
+	if (mask) {
+		val = xive_esb_read(xd, XIVE_ESB_SET_PQ_01);
+		if (!xd->stale_p && !!(val & XIVE_ESB_VAL_P))
+			xd->saved_p = true;
+		xd->stale_p = false;
+	} else if (xd->saved_p) {
+		xive_esb_read(xd, XIVE_ESB_SET_PQ_10);
+		xd->saved_p = false;
+	} else {
+		xive_esb_read(xd, XIVE_ESB_SET_PQ_00);
+		xd->stale_p = false;
+	}
+}
+
+/*
+ * Try to chose "cpu" as a new interrupt target. Increments
+ * the queue accounting for that target if it's not already
+ * full.
+ */
+static bool xive_try_pick_target(int cpu)
+{
+	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
+	struct xive_q *q = &xc->queue[xive_irq_priority];
+	int max;
+
+	/*
+	 * Calculate max number of interrupts in that queue.
+	 *
+	 * We leave a gap of 1 just in case...
+	 */
+	max = (q->msk + 1) - 1;
+	return !!atomic_add_unless(&q->count, 1, max);
+}
+
+/*
+ * Un-account an interrupt for a target CPU. We don't directly
+ * decrement q->count since the interrupt might still be present
+ * in the queue.
+ *
+ * Instead increment a separate counter "pending_count" which
+ * will be substracted from "count" later when that CPU observes
+ * the queue to be empty.
+ */
+static void xive_dec_target_count(int cpu)
+{
+	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
+	struct xive_q *q = &xc->queue[xive_irq_priority];
+
+	if (WARN_ON(cpu < 0 || !xc)) {
+		pr_err("%s: cpu=%d xc=%p\n", __func__, cpu, xc);
+		return;
+	}
+
+	/*
+	 * We increment the "pending count" which will be used
+	 * to decrement the target queue count whenever it's next
+	 * processed and found empty. This ensure that we don't
+	 * decrement while we still have the interrupt there
+	 * occupying a slot.
+	 */
+	atomic_inc(&q->pending_count);
+}
+
+/* Find a tentative CPU target in a CPU mask */
+static int xive_find_target_in_mask(const struct cpumask *mask,
+				    unsigned int fuzz)
+{
+	int cpu, first, num, i;
+
+	/* Pick up a starting point CPU in the mask based on  fuzz */
+	num = min_t(int, cpumask_weight(mask), nr_cpu_ids);
+	first = fuzz % num;
+
+	/* Locate it */
+	cpu = cpumask_first(mask);
+	for (i = 0; i < first && cpu < nr_cpu_ids; i++)
+		cpu = cpumask_next(cpu, mask);
+
+	/* Sanity check */
+	if (WARN_ON(cpu >= nr_cpu_ids))
+		cpu = cpumask_first(cpu_online_mask);
+
+	/* Remember first one to handle wrap-around */
+	first = cpu;
+
+	/*
+	 * Now go through the entire mask until we find a valid
+	 * target.
+	 */
+	do {
+		/*
+		 * We re-check online as the fallback case passes us
+		 * an untested affinity mask
+		 */
+		if (cpu_online(cpu) && xive_try_pick_target(cpu))
+			return cpu;
+		cpu = cpumask_next(cpu, mask);
+		/* Wrap around */
+		if (cpu >= nr_cpu_ids)
+			cpu = cpumask_first(mask);
+	} while (cpu != first);
+
+	return -1;
+}
+
+/*
+ * Pick a target CPU for an interrupt. This is done at
+ * startup or if the affinity is changed in a way that
+ * invalidates the current target.
+ */
+static int xive_pick_irq_target(struct irq_data *d,
+				const struct cpumask *affinity)
+{
+	static unsigned int fuzz;
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+	cpumask_var_t mask;
+	int cpu = -1;
+
+	/*
+	 * If we have chip IDs, first we try to build a mask of
+	 * CPUs matching the CPU and find a target in there
+	 */
+	if (xd->src_chip != XIVE_INVALID_CHIP_ID &&
+		zalloc_cpumask_var(&mask, GFP_ATOMIC)) {
+		/* Build a mask of matching chip IDs */
+		for_each_cpu_and(cpu, affinity, cpu_online_mask) {
+			struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
+			if (xc->chip_id == xd->src_chip)
+				cpumask_set_cpu(cpu, mask);
+		}
+		/* Try to find a target */
+		if (cpumask_empty(mask))
+			cpu = -1;
+		else
+			cpu = xive_find_target_in_mask(mask, fuzz++);
+		free_cpumask_var(mask);
+		if (cpu >= 0)
+			return cpu;
+		fuzz--;
+	}
+
+	/* No chip IDs, fallback to using the affinity mask */
+	return xive_find_target_in_mask(affinity, fuzz++);
+}
+
+static unsigned int xive_irq_startup(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+	int target, rc;
+
+	xd->saved_p = false;
+	xd->stale_p = false;
+
+	pr_debug("%s: irq %d [0x%x] data @%p\n", __func__, d->irq, hw_irq, d);
+
+	/* Pick a target */
+	target = xive_pick_irq_target(d, irq_data_get_affinity_mask(d));
+	if (target == XIVE_INVALID_TARGET) {
+		/* Try again breaking affinity */
+		target = xive_pick_irq_target(d, cpu_online_mask);
+		if (target == XIVE_INVALID_TARGET)
+			return -ENXIO;
+		pr_warn("irq %d started with broken affinity\n", d->irq);
+	}
+
+	/* Sanity check */
+	if (WARN_ON(target == XIVE_INVALID_TARGET ||
+		    target >= nr_cpu_ids))
+		target = smp_processor_id();
+
+	xd->target = target;
+
+	/*
+	 * Configure the logical number to be the Linux IRQ number
+	 * and set the target queue
+	 */
+	rc = xive_ops->configure_irq(hw_irq,
+				     get_hard_smp_processor_id(target),
+				     xive_irq_priority, d->irq);
+	if (rc)
+		return rc;
+
+	/* Unmask the ESB */
+	xive_do_source_set_mask(xd, false);
+
+	return 0;
+}
+
+/* called with irq descriptor lock held */
+static void xive_irq_shutdown(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+
+	pr_debug("%s: irq %d [0x%x] data @%p\n", __func__, d->irq, hw_irq, d);
+
+	if (WARN_ON(xd->target == XIVE_INVALID_TARGET))
+		return;
+
+	/* Mask the interrupt at the source */
+	xive_do_source_set_mask(xd, true);
+
+	/*
+	 * Mask the interrupt in HW in the IVT/EAS and set the number
+	 * to be the "bad" IRQ number
+	 */
+	xive_ops->configure_irq(hw_irq,
+				get_hard_smp_processor_id(xd->target),
+				0xff, XIVE_BAD_IRQ);
+
+	xive_dec_target_count(xd->target);
+	xd->target = XIVE_INVALID_TARGET;
+}
+
+static void xive_irq_unmask(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+
+	pr_debug("%s: irq %d data @%p\n", __func__, d->irq, xd);
+
+	xive_do_source_set_mask(xd, false);
+}
+
+static void xive_irq_mask(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+
+	pr_debug("%s: irq %d data @%p\n", __func__, d->irq, xd);
+
+	xive_do_source_set_mask(xd, true);
+}
+
+static int xive_irq_set_affinity(struct irq_data *d,
+				 const struct cpumask *cpumask,
+				 bool force)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+	u32 target, old_target;
+	int rc = 0;
+
+	pr_debug("%s: irq %d/0x%x\n", __func__, d->irq, hw_irq);
+
+	/* Is this valid ? */
+	if (cpumask_any_and(cpumask, cpu_online_mask) >= nr_cpu_ids)
+		return -EINVAL;
+
+	/*
+	 * If existing target is already in the new mask, and is
+	 * online then do nothing.
+	 */
+	if (xd->target != XIVE_INVALID_TARGET &&
+	    cpu_online(xd->target) &&
+	    cpumask_test_cpu(xd->target, cpumask))
+		return IRQ_SET_MASK_OK;
+
+	/* Pick a new target */
+	target = xive_pick_irq_target(d, cpumask);
+
+	/* No target found */
+	if (target == XIVE_INVALID_TARGET)
+		return -ENXIO;
+
+	/* Sanity check */
+	if (WARN_ON(target >= nr_cpu_ids))
+		target = smp_processor_id();
+
+	old_target = xd->target;
+
+	/*
+	 * Only configure the irq if it's not currently passed-through to
+	 * a KVM guest
+	 */
+	if (!irqd_is_forwarded_to_vcpu(d))
+		rc = xive_ops->configure_irq(hw_irq,
+					     get_hard_smp_processor_id(target),
+					     xive_irq_priority, d->irq);
+	if (rc < 0) {
+		pr_err("Error %d reconfiguring irq %d\n", rc, d->irq);
+		return rc;
+	}
+
+	pr_debug("  target: 0x%x\n", target);
+	xd->target = target;
+
+	/* Give up previous target */
+	if (old_target != XIVE_INVALID_TARGET)
+	    xive_dec_target_count(old_target);
+
+	return IRQ_SET_MASK_OK;
+}
+
+static int xive_irq_set_type(struct irq_data *d, unsigned int flow_type)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+
+	/*
+	 * We only support these. This has really no effect other than setting
+	 * the corresponding descriptor bits mind you but those will in turn
+	 * affect the resend function when re-enabling an edge interrupt.
+	 *
+	 * Set the default to edge as explained in map().
+	 */
+	if (flow_type == IRQ_TYPE_DEFAULT || flow_type == IRQ_TYPE_NONE)
+		flow_type = IRQ_TYPE_EDGE_RISING;
+
+	if (flow_type != IRQ_TYPE_EDGE_RISING &&
+	    flow_type != IRQ_TYPE_LEVEL_LOW)
+		return -EINVAL;
+
+	irqd_set_trigger_type(d, flow_type);
+
+	/*
+	 * Double check it matches what the FW thinks
+	 *
+	 * NOTE: We don't know yet if the PAPR interface will provide
+	 * the LSI vs MSI information apart from the device-tree so
+	 * this check might have to move into an optional backend call
+	 * that is specific to the native backend
+	 */
+	if ((flow_type == IRQ_TYPE_LEVEL_LOW) !=
+	    !!(xd->flags & XIVE_IRQ_FLAG_LSI)) {
+		pr_warn("Interrupt %d (HW 0x%x) type mismatch, Linux says %s, FW says %s\n",
+			d->irq, (u32)irqd_to_hwirq(d),
+			(flow_type == IRQ_TYPE_LEVEL_LOW) ? "Level" : "Edge",
+			(xd->flags & XIVE_IRQ_FLAG_LSI) ? "Level" : "Edge");
+	}
+
+	return IRQ_SET_MASK_OK_NOCOPY;
+}
+
+static int xive_irq_retrigger(struct irq_data *d)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+
+	/* This should be only for MSIs */
+	if (WARN_ON(xd->flags & XIVE_IRQ_FLAG_LSI))
+		return 0;
+
+	/*
+	 * To perform a retrigger, we first set the PQ bits to
+	 * 11, then perform an EOI.
+	 */
+	xive_esb_read(xd, XIVE_ESB_SET_PQ_11);
+	xive_do_source_eoi(xd);
+
+	return 1;
+}
+
+/*
+ * Caller holds the irq descriptor lock, so this won't be called
+ * concurrently with xive_get_irqchip_state on the same interrupt.
+ */
+static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
+	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+	int rc;
+	u8 pq;
+
+	/*
+	 * This is called by KVM with state non-NULL for enabling
+	 * pass-through or NULL for disabling it
+	 */
+	if (state) {
+		irqd_set_forwarded_to_vcpu(d);
+
+		/* Set it to PQ=10 state to prevent further sends */
+		pq = xive_esb_read(xd, XIVE_ESB_SET_PQ_10);
+		if (!xd->stale_p) {
+			xd->saved_p = !!(pq & XIVE_ESB_VAL_P);
+			xd->stale_p = !xd->saved_p;
+		}
+
+		/* No target ? nothing to do */
+		if (xd->target == XIVE_INVALID_TARGET) {
+			/*
+			 * An untargetted interrupt should have been
+			 * also masked at the source
+			 */
+			WARN_ON(xd->saved_p);
+
+			return 0;
+		}
+
+		/*
+		 * If P was set, adjust state to PQ=11 to indicate
+		 * that a resend is needed for the interrupt to reach
+		 * the guest. Also remember the value of P.
+		 *
+		 * This also tells us that it's in flight to a host queue
+		 * or has already been fetched but hasn't been EOIed yet
+		 * by the host. This it's potentially using up a host
+		 * queue slot. This is important to know because as long
+		 * as this is the case, we must not hard-unmask it when
+		 * "returning" that interrupt to the host.
+		 *
+		 * This saved_p is cleared by the host EOI, when we know
+		 * for sure the queue slot is no longer in use.
+		 */
+		if (xd->saved_p) {
+			xive_esb_read(xd, XIVE_ESB_SET_PQ_11);
+
+			/*
+			 * Sync the XIVE source HW to ensure the interrupt
+			 * has gone through the EAS before we change its
+			 * target to the guest. That should guarantee us
+			 * that we *will* eventually get an EOI for it on
+			 * the host. Otherwise there would be a small window
+			 * for P to be seen here but the interrupt going
+			 * to the guest queue.
+			 */
+			if (xive_ops->sync_source)
+				xive_ops->sync_source(hw_irq);
+		}
+	} else {
+		irqd_clr_forwarded_to_vcpu(d);
+
+		/* No host target ? hard mask and return */
+		if (xd->target == XIVE_INVALID_TARGET) {
+			xive_do_source_set_mask(xd, true);
+			return 0;
+		}
+
+		/*
+		 * Sync the XIVE source HW to ensure the interrupt
+		 * has gone through the EAS before we change its
+		 * target to the host.
+		 */
+		if (xive_ops->sync_source)
+			xive_ops->sync_source(hw_irq);
+
+		/*
+		 * By convention we are called with the interrupt in
+		 * a PQ=10 or PQ=11 state, ie, it won't fire and will
+		 * have latched in Q whether there's a pending HW
+		 * interrupt or not.
+		 *
+		 * First reconfigure the target.
+		 */
+		rc = xive_ops->configure_irq(hw_irq,
+					     get_hard_smp_processor_id(xd->target),
+					     xive_irq_priority, d->irq);
+		if (rc)
+			return rc;
+
+		/*
+		 * Then if saved_p is not set, effectively re-enable the
+		 * interrupt with an EOI. If it is set, we know there is
+		 * still a message in a host queue somewhere that will be
+		 * EOId eventually.
+		 *
+		 * Note: We don't check irqd_irq_disabled(). Effectively,
+		 * we *will* let the irq get through even if masked if the
+		 * HW is still firing it in order to deal with the whole
+		 * saved_p business properly. If the interrupt triggers
+		 * while masked, the generic code will re-mask it anyway.
+		 */
+		if (!xd->saved_p)
+			xive_do_source_eoi(xd);
+
+	}
+	return 0;
+}
+
+/* Called with irq descriptor lock held. */
+static int xive_get_irqchip_state(struct irq_data *data,
+				  enum irqchip_irq_state which, bool *state)
+{
+	struct xive_irq_data *xd = irq_data_get_irq_handler_data(data);
+	u8 pq;
+
+	switch (which) {
+	case IRQCHIP_STATE_ACTIVE:
+		pq = xive_esb_read(xd, XIVE_ESB_GET);
+
+		/*
+		 * The esb value being all 1's means we couldn't get
+		 * the PQ state of the interrupt through mmio. It may
+		 * happen, for example when querying a PHB interrupt
+		 * while the PHB is in an error state. We consider the
+		 * interrupt to be inactive in that case.
+		 */
+		*state = (pq != XIVE_ESB_INVALID) && !xd->stale_p &&
+			(xd->saved_p || (!!(pq & XIVE_ESB_VAL_P) &&
+			 !irqd_irq_disabled(data)));
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static struct irq_chip xive_irq_chip = {
+	.name = "XIVE-IRQ",
+	.irq_startup = xive_irq_startup,
+	.irq_shutdown = xive_irq_shutdown,
+	.irq_eoi = xive_irq_eoi,
+	.irq_mask = xive_irq_mask,
+	.irq_unmask = xive_irq_unmask,
+	.irq_set_affinity = xive_irq_set_affinity,
+	.irq_set_type = xive_irq_set_type,
+	.irq_retrigger = xive_irq_retrigger,
+	.irq_set_vcpu_affinity = xive_irq_set_vcpu_affinity,
+	.irq_get_irqchip_state = xive_get_irqchip_state,
+};
+
+bool is_xive_irq(struct irq_chip *chip)
+{
+	return chip == &xive_irq_chip;
+}
+EXPORT_SYMBOL_GPL(is_xive_irq);
+
+void xive_cleanup_irq_data(struct xive_irq_data *xd)
+{
+	pr_debug("%s for HW 0x%x\n", __func__, xd->hw_irq);
+
+	if (xd->eoi_mmio) {
+		iounmap(xd->eoi_mmio);
+		if (xd->eoi_mmio == xd->trig_mmio)
+			xd->trig_mmio = NULL;
+		xd->eoi_mmio = NULL;
+	}
+	if (xd->trig_mmio) {
+		iounmap(xd->trig_mmio);
+		xd->trig_mmio = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(xive_cleanup_irq_data);
+
+static int xive_irq_alloc_data(unsigned int virq, irq_hw_number_t hw)
+{
+	struct xive_irq_data *xd;
+	int rc;
+
+	xd = kzalloc(sizeof(struct xive_irq_data), GFP_KERNEL);
+	if (!xd)
+		return -ENOMEM;
+	rc = xive_ops->populate_irq_data(hw, xd);
+	if (rc) {
+		kfree(xd);
+		return rc;
+	}
+	xd->target = XIVE_INVALID_TARGET;
+	irq_set_handler_data(virq, xd);
+
+	/*
+	 * Turn OFF by default the interrupt being mapped. A side
+	 * effect of this check is the mapping the ESB page of the
+	 * interrupt in the Linux address space. This prevents page
+	 * fault issues in the crash handler which masks all
+	 * interrupts.
+	 */
+	xive_esb_read(xd, XIVE_ESB_SET_PQ_01);
+
+	return 0;
+}
+
+void xive_irq_free_data(unsigned int virq)
+{
+	struct xive_irq_data *xd = irq_get_handler_data(virq);
+
+	if (!xd)
+		return;
+	irq_set_handler_data(virq, NULL);
+	xive_cleanup_irq_data(xd);
+	kfree(xd);
+}
+EXPORT_SYMBOL_GPL(xive_irq_free_data);
+
+#ifdef CONFIG_SMP
+
+static void xive_cause_ipi(int cpu)
+{
+	struct xive_cpu *xc;
+	struct xive_irq_data *xd;
+
+	xc = per_cpu(xive_cpu, cpu);
+
+	DBG_VERBOSE("IPI CPU %d -> %d (HW IRQ 0x%x)\n",
+		    smp_processor_id(), cpu, xc->hw_ipi);
+
+	xd = &xc->ipi_data;
+	if (WARN_ON(!xd->trig_mmio))
+		return;
+	out_be64(xd->trig_mmio, 0);
+}
+
+static irqreturn_t xive_muxed_ipi_action(int irq, void *dev_id)
+{
+	return smp_ipi_demux();
+}
+
+static void xive_ipi_eoi(struct irq_data *d)
+{
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+
+	/* Handle possible race with unplug and drop stale IPIs */
+	if (!xc)
+		return;
+
+	DBG_VERBOSE("IPI eoi: irq=%d [0x%lx] (HW IRQ 0x%x) pending=%02x\n",
+		    d->irq, irqd_to_hwirq(d), xc->hw_ipi, xc->pending_prio);
+
+	xive_do_source_eoi(&xc->ipi_data);
+	xive_do_queue_eoi(xc);
+}
+
+static void xive_ipi_do_nothing(struct irq_data *d)
+{
+	/*
+	 * Nothing to do, we never mask/unmask IPIs, but the callback
+	 * has to exist for the struct irq_chip.
+	 */
+}
+
+static struct irq_chip xive_ipi_chip = {
+	.name = "XIVE-IPI",
+	.irq_eoi = xive_ipi_eoi,
+	.irq_mask = xive_ipi_do_nothing,
+	.irq_unmask = xive_ipi_do_nothing,
+};
+
+/*
+ * IPIs are marked per-cpu. We use separate HW interrupts under the
+ * hood but associated with the same "linux" interrupt
+ */
+struct xive_ipi_alloc_info {
+	irq_hw_number_t hwirq;
+};
+
+static int xive_ipi_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				     unsigned int nr_irqs, void *arg)
+{
+	struct xive_ipi_alloc_info *info = arg;
+	int i;
+
+	for (i = 0; i < nr_irqs; i++) {
+		irq_domain_set_info(domain, virq + i, info->hwirq + i, &xive_ipi_chip,
+				    domain->host_data, handle_percpu_irq,
+				    NULL, NULL);
+	}
+	return 0;
+}
+
+static const struct irq_domain_ops xive_ipi_irq_domain_ops = {
+	.alloc  = xive_ipi_irq_domain_alloc,
+};
+
+static int __init xive_init_ipis(void)
+{
+	struct fwnode_handle *fwnode;
+	struct irq_domain *ipi_domain;
+	unsigned int node;
+	int ret = -ENOMEM;
+
+	fwnode = irq_domain_alloc_named_fwnode("XIVE-IPI");
+	if (!fwnode)
+		goto out;
+
+	ipi_domain = irq_domain_create_linear(fwnode, nr_node_ids,
+					      &xive_ipi_irq_domain_ops, NULL);
+	if (!ipi_domain)
+		goto out_free_fwnode;
+
+	xive_ipis = kcalloc(nr_node_ids, sizeof(*xive_ipis), GFP_KERNEL | __GFP_NOFAIL);
+	if (!xive_ipis)
+		goto out_free_domain;
+
+	for_each_node(node) {
+		struct xive_ipi_desc *xid = &xive_ipis[node];
+		struct xive_ipi_alloc_info info = { node };
+
+		/*
+		 * Map one IPI interrupt per node for all cpus of that node.
+		 * Since the HW interrupt number doesn't have any meaning,
+		 * simply use the node number.
+		 */
+		ret = irq_domain_alloc_irqs(ipi_domain, 1, node, &info);
+		if (ret < 0)
+			goto out_free_xive_ipis;
+		xid->irq = ret;
+
+		snprintf(xid->name, sizeof(xid->name), "IPI-%d", node);
+	}
+
+	return ret;
+
+out_free_xive_ipis:
+	kfree(xive_ipis);
+out_free_domain:
+	irq_domain_remove(ipi_domain);
+out_free_fwnode:
+	irq_domain_free_fwnode(fwnode);
+out:
+	return ret;
+}
+
+static int xive_request_ipi(unsigned int cpu)
+{
+	struct xive_ipi_desc *xid = &xive_ipis[early_cpu_to_node(cpu)];
+	int ret;
+
+	if (atomic_inc_return(&xid->started) > 1)
+		return 0;
+
+	ret = request_irq(xid->irq, xive_muxed_ipi_action,
+			  IRQF_NO_DEBUG | IRQF_PERCPU | IRQF_NO_THREAD,
+			  xid->name, NULL);
+
+	WARN(ret < 0, "Failed to request IPI %d: %d\n", xid->irq, ret);
+	return ret;
+}
+
+static int xive_setup_cpu_ipi(unsigned int cpu)
+{
+	unsigned int xive_ipi_irq = xive_ipi_cpu_to_irq(cpu);
+	struct xive_cpu *xc;
+	int rc;
+
+	pr_debug("Setting up IPI for CPU %d\n", cpu);
+
+	xc = per_cpu(xive_cpu, cpu);
+
+	/* Check if we are already setup */
+	if (xc->hw_ipi != XIVE_BAD_IRQ)
+		return 0;
+
+	/* Register the IPI */
+	xive_request_ipi(cpu);
+
+	/* Grab an IPI from the backend, this will populate xc->hw_ipi */
+	if (xive_ops->get_ipi(cpu, xc))
+		return -EIO;
+
+	/*
+	 * Populate the IRQ data in the xive_cpu structure and
+	 * configure the HW / enable the IPIs.
+	 */
+	rc = xive_ops->populate_irq_data(xc->hw_ipi, &xc->ipi_data);
+	if (rc) {
+		pr_err("Failed to populate IPI data on CPU %d\n", cpu);
+		return -EIO;
+	}
+	rc = xive_ops->configure_irq(xc->hw_ipi,
+				     get_hard_smp_processor_id(cpu),
+				     xive_irq_priority, xive_ipi_irq);
+	if (rc) {
+		pr_err("Failed to map IPI CPU %d\n", cpu);
+		return -EIO;
+	}
+	pr_debug("CPU %d HW IPI 0x%x, virq %d, trig_mmio=%p\n", cpu,
+		 xc->hw_ipi, xive_ipi_irq, xc->ipi_data.trig_mmio);
+
+	/* Unmask it */
+	xive_do_source_set_mask(&xc->ipi_data, false);
+
+	return 0;
+}
+
+noinstr static void xive_cleanup_cpu_ipi(unsigned int cpu, struct xive_cpu *xc)
+{
+	unsigned int xive_ipi_irq = xive_ipi_cpu_to_irq(cpu);
+
+	/* Disable the IPI and free the IRQ data */
+
+	/* Already cleaned up ? */
+	if (xc->hw_ipi == XIVE_BAD_IRQ)
+		return;
+
+	/* TODO: clear IPI mapping */
+
+	/* Mask the IPI */
+	xive_do_source_set_mask(&xc->ipi_data, true);
+
+	/*
+	 * Note: We don't call xive_cleanup_irq_data() to free
+	 * the mappings as this is called from an IPI on kexec
+	 * which is not a safe environment to call iounmap()
+	 */
+
+	/* Deconfigure/mask in the backend */
+	xive_ops->configure_irq(xc->hw_ipi, hard_smp_processor_id(),
+				0xff, xive_ipi_irq);
+
+	/* Free the IPIs in the backend */
+	xive_ops->put_ipi(cpu, xc);
+}
+
+void __init xive_smp_probe(void)
+{
+	smp_ops->cause_ipi = xive_cause_ipi;
+
+	/* Register the IPI */
+	xive_init_ipis();
+
+	/* Allocate and setup IPI for the boot CPU */
+	xive_setup_cpu_ipi(smp_processor_id());
+}
+
+#endif /* CONFIG_SMP */
+
+static int xive_irq_domain_map(struct irq_domain *h, unsigned int virq,
+			       irq_hw_number_t hw)
+{
+	int rc;
+
+	/*
+	 * Mark interrupts as edge sensitive by default so that resend
+	 * actually works. Will fix that up below if needed.
+	 */
+	irq_clear_status_flags(virq, IRQ_LEVEL);
+
+	rc = xive_irq_alloc_data(virq, hw);
+	if (rc)
+		return rc;
+
+	irq_set_chip_and_handler(virq, &xive_irq_chip, handle_fasteoi_irq);
+
+	return 0;
+}
+
+static void xive_irq_domain_unmap(struct irq_domain *d, unsigned int virq)
+{
+	xive_irq_free_data(virq);
+}
+
+static int xive_irq_domain_xlate(struct irq_domain *h, struct device_node *ct,
+				 const u32 *intspec, unsigned int intsize,
+				 irq_hw_number_t *out_hwirq, unsigned int *out_flags)
+
+{
+	*out_hwirq = intspec[0];
+
+	/*
+	 * If intsize is at least 2, we look for the type in the second cell,
+	 * we assume the LSB indicates a level interrupt.
+	 */
+	if (intsize > 1) {
+		if (intspec[1] & 1)
+			*out_flags = IRQ_TYPE_LEVEL_LOW;
+		else
+			*out_flags = IRQ_TYPE_EDGE_RISING;
+	} else
+		*out_flags = IRQ_TYPE_LEVEL_LOW;
+
+	return 0;
+}
+
+static int xive_irq_domain_match(struct irq_domain *h, struct device_node *node,
+				 enum irq_domain_bus_token bus_token)
+{
+	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_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
+
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+static int xive_irq_domain_translate(struct irq_domain *d,
+				     struct irq_fwspec *fwspec,
+				     unsigned long *hwirq,
+				     unsigned int *type)
+{
+	return xive_irq_domain_xlate(d, to_of_node(fwspec->fwnode),
+				     fwspec->param, fwspec->param_count,
+				     hwirq, type);
+}
+
+static int xive_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
+				 unsigned int nr_irqs, void *arg)
+{
+	struct irq_fwspec *fwspec = arg;
+	irq_hw_number_t hwirq;
+	unsigned int type = IRQ_TYPE_NONE;
+	int i, rc;
+
+	rc = xive_irq_domain_translate(domain, fwspec, &hwirq, &type);
+	if (rc)
+		return rc;
+
+	pr_debug("%s %d/0x%lx #%d\n", __func__, virq, hwirq, nr_irqs);
+
+	for (i = 0; i < nr_irqs; i++) {
+		/* TODO: call xive_irq_domain_map() */
+
+		/*
+		 * Mark interrupts as edge sensitive by default so that resend
+		 * actually works. Will fix that up below if needed.
+		 */
+		irq_clear_status_flags(virq, IRQ_LEVEL);
+
+		/* allocates and sets handler data */
+		rc = xive_irq_alloc_data(virq + i, hwirq + i);
+		if (rc)
+			return rc;
+
+		irq_domain_set_hwirq_and_chip(domain, virq + i, hwirq + i,
+					      &xive_irq_chip, domain->host_data);
+		irq_set_handler(virq + i, handle_fasteoi_irq);
+	}
+
+	return 0;
+}
+
+static void xive_irq_domain_free(struct irq_domain *domain,
+				 unsigned int virq, unsigned int nr_irqs)
+{
+	int i;
+
+	pr_debug("%s %d #%d\n", __func__, virq, nr_irqs);
+
+	for (i = 0; i < nr_irqs; i++)
+		xive_irq_free_data(virq + i);
+}
+#endif
+
+static const struct irq_domain_ops xive_irq_domain_ops = {
+#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
+	.alloc	= xive_irq_domain_alloc,
+	.free	= xive_irq_domain_free,
+	.translate = xive_irq_domain_translate,
+#endif
+	.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)
+{
+	xive_irq_domain = irq_domain_add_tree(np, &xive_irq_domain_ops, NULL);
+	if (WARN_ON(xive_irq_domain == NULL))
+		return;
+	irq_set_default_host(xive_irq_domain);
+}
+
+static void xive_cleanup_cpu_queues(unsigned int cpu, struct xive_cpu *xc)
+{
+	if (xc->queue[xive_irq_priority].qpage)
+		xive_ops->cleanup_queue(cpu, xc, xive_irq_priority);
+}
+
+static int xive_setup_cpu_queues(unsigned int cpu, struct xive_cpu *xc)
+{
+	int rc = 0;
+
+	/* We setup 1 queues for now with a 64k page */
+	if (!xc->queue[xive_irq_priority].qpage)
+		rc = xive_ops->setup_queue(cpu, xc, xive_irq_priority);
+
+	return rc;
+}
+
+static int xive_prepare_cpu(unsigned int cpu)
+{
+	struct xive_cpu *xc;
+
+	xc = per_cpu(xive_cpu, cpu);
+	if (!xc) {
+		xc = kzalloc_node(sizeof(struct xive_cpu),
+				  GFP_KERNEL, cpu_to_node(cpu));
+		if (!xc)
+			return -ENOMEM;
+		xc->hw_ipi = XIVE_BAD_IRQ;
+		xc->chip_id = XIVE_INVALID_CHIP_ID;
+		if (xive_ops->prepare_cpu)
+			xive_ops->prepare_cpu(cpu, xc);
+
+		per_cpu(xive_cpu, cpu) = xc;
+	}
+
+	/* Setup EQs if not already */
+	return xive_setup_cpu_queues(cpu, xc);
+}
+
+static void xive_setup_cpu(void)
+{
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+
+	/* The backend might have additional things to do */
+	if (xive_ops->setup_cpu)
+		xive_ops->setup_cpu(smp_processor_id(), xc);
+
+	/* Set CPPR to 0xff to enable flow of interrupts */
+	xc->cppr = 0xff;
+	out_8(xive_tima + xive_tima_offset + TM_CPPR, 0xff);
+}
+
+#ifdef CONFIG_SMP
+void xive_smp_setup_cpu(void)
+{
+	pr_debug("SMP setup CPU %d\n", smp_processor_id());
+
+	/* This will have already been done on the boot CPU */
+	if (smp_processor_id() != boot_cpuid)
+		xive_setup_cpu();
+
+}
+
+int xive_smp_prepare_cpu(unsigned int cpu)
+{
+	int rc;
+
+	/* Allocate per-CPU data and queues */
+	rc = xive_prepare_cpu(cpu);
+	if (rc)
+		return rc;
+
+	/* Allocate and setup IPI for the new CPU */
+	return xive_setup_cpu_ipi(cpu);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static void xive_flush_cpu_queue(unsigned int cpu, struct xive_cpu *xc)
+{
+	u32 irq;
+
+	/* We assume local irqs are disabled */
+	WARN_ON(!irqs_disabled());
+
+	/* Check what's already in the CPU queue */
+	while ((irq = xive_scan_interrupts(xc, false)) != 0) {
+		/*
+		 * We need to re-route that interrupt to its new destination.
+		 * First get and lock the descriptor
+		 */
+		struct irq_desc *desc = irq_to_desc(irq);
+		struct irq_data *d = irq_desc_get_irq_data(desc);
+		struct xive_irq_data *xd;
+
+		/*
+		 * Ignore anything that isn't a XIVE irq and ignore
+		 * IPIs, so can just be dropped.
+		 */
+		if (d->domain != xive_irq_domain)
+			continue;
+
+		/*
+		 * The IRQ should have already been re-routed, it's just a
+		 * stale in the old queue, so re-trigger it in order to make
+		 * it reach is new destination.
+		 */
+#ifdef DEBUG_FLUSH
+		pr_info("CPU %d: Got irq %d while offline, re-sending...\n",
+			cpu, irq);
+#endif
+		raw_spin_lock(&desc->lock);
+		xd = irq_desc_get_handler_data(desc);
+
+		/*
+		 * Clear saved_p to indicate that it's no longer pending
+		 */
+		xd->saved_p = false;
+
+		/*
+		 * For LSIs, we EOI, this will cause a resend if it's
+		 * still asserted. Otherwise do an MSI retrigger.
+		 */
+		if (xd->flags & XIVE_IRQ_FLAG_LSI)
+			xive_do_source_eoi(xd);
+		else
+			xive_irq_retrigger(d);
+
+		raw_spin_unlock(&desc->lock);
+	}
+}
+
+void xive_smp_disable_cpu(void)
+{
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+	unsigned int cpu = smp_processor_id();
+
+	/* Migrate interrupts away from the CPU */
+	irq_migrate_all_off_this_cpu();
+
+	/* Set CPPR to 0 to disable flow of interrupts */
+	xc->cppr = 0;
+	out_8(xive_tima + xive_tima_offset + TM_CPPR, 0);
+
+	/* Flush everything still in the queue */
+	xive_flush_cpu_queue(cpu, xc);
+
+	/* Re-enable CPPR  */
+	xc->cppr = 0xff;
+	out_8(xive_tima + xive_tima_offset + TM_CPPR, 0xff);
+}
+
+void xive_flush_interrupt(void)
+{
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+	unsigned int cpu = smp_processor_id();
+
+	/* Called if an interrupt occurs while the CPU is hot unplugged */
+	xive_flush_cpu_queue(cpu, xc);
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
+#endif /* CONFIG_SMP */
+
+noinstr void xive_teardown_cpu(void)
+{
+	struct xive_cpu *xc = __this_cpu_read(xive_cpu);
+	unsigned int cpu = smp_processor_id();
+
+	/* Set CPPR to 0 to disable flow of interrupts */
+	xc->cppr = 0;
+	out_8(xive_tima + xive_tima_offset + TM_CPPR, 0);
+
+	if (xive_ops->teardown_cpu)
+		xive_ops->teardown_cpu(cpu, xc);
+
+#ifdef CONFIG_SMP
+	/* Get rid of IPI */
+	xive_cleanup_cpu_ipi(cpu, xc);
+#endif
+
+	/* Disable and free the queues */
+	xive_cleanup_cpu_queues(cpu, xc);
+}
+
+void xive_shutdown(void)
+{
+	xive_ops->shutdown();
+}
+
+bool __init xive_core_init(struct device_node *np, const struct xive_ops *ops,
+			   void __iomem *area, u32 offset, u8 max_prio)
+{
+	xive_tima = area;
+	xive_tima_offset = offset;
+	xive_ops = ops;
+	xive_irq_priority = max_prio;
+
+	ppc_md.get_irq = xive_get_irq;
+	__xive_enabled = true;
+
+	pr_debug("Initializing host..\n");
+	xive_init_host(np);
+
+	pr_debug("Initializing boot CPU..\n");
+
+	/* Allocate per-CPU data and queues */
+	xive_prepare_cpu(smp_processor_id());
+
+	/* Get ready for interrupts */
+	xive_setup_cpu();
+
+	pr_info("Interrupt handling initialized with %s backend\n",
+		xive_ops->name);
+	pr_info("Using priority %d for all interrupts\n", max_prio);
+
+	return true;
+}
+
+__be32 *xive_queue_page_alloc(unsigned int cpu, u32 queue_shift)
+{
+	unsigned int alloc_order;
+	struct page *pages;
+	__be32 *qpage;
+
+	alloc_order = xive_alloc_order(queue_shift);
+	pages = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, alloc_order);
+	if (!pages)
+		return ERR_PTR(-ENOMEM);
+	qpage = (__be32 *)page_address(pages);
+	memset(qpage, 0, 1 << queue_shift);
+
+	return qpage;
+}
+
+static int __init xive_off(char *arg)
+{
+	xive_cmdline_disabled = true;
+	return 1;
+}
+__setup("xive=off", xive_off);
+
+static int __init xive_store_eoi_cmdline(char *arg)
+{
+	if (!arg)
+		return 1;
+
+	if (strncmp(arg, "off", 3) == 0) {
+		pr_info("StoreEOI disabled on kernel command line\n");
+		xive_store_eoi = false;
+	}
+	return 1;
+}
+__setup("xive.store-eoi=", xive_store_eoi_cmdline);
+
+#ifdef CONFIG_DEBUG_FS
+static void xive_debug_show_ipi(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
+		{
+			char buffer[128];
+
+			xive_irq_data_dump(&xc->ipi_data, buffer, sizeof(buffer));
+			seq_printf(m, "IPI=0x%08x %s", xc->hw_ipi, buffer);
+		}
+#endif
+	}
+	seq_puts(m, "\n");
+}
+
+static void xive_debug_show_irq(struct seq_file *m, struct irq_data *d)
+{
+	unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+	int rc;
+	u32 target;
+	u8 prio;
+	u32 lirq;
+	char buffer[128];
+
+	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);
+
+	xive_irq_data_dump(irq_data_get_irq_handler_data(d), buffer, sizeof(buffer));
+	seq_puts(m, buffer);
+	seq_puts(m, "\n");
+}
+
+static int xive_irq_debug_show(struct seq_file *m, void *private)
+{
+	unsigned int i;
+	struct irq_desc *desc;
+
+	for_each_irq_desc(i, desc) {
+		struct irq_data *d = irq_domain_get_irq_data(xive_irq_domain, i);
+
+		if (d)
+			xive_debug_show_irq(m, d);
+	}
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(xive_irq_debug);
+
+static int xive_ipi_debug_show(struct seq_file *m, void *private)
+{
+	int cpu;
+
+	if (xive_ops->debug_show)
+		xive_ops->debug_show(m, private);
+
+	for_each_online_cpu(cpu)
+		xive_debug_show_ipi(m, cpu);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(xive_ipi_debug);
+
+static void xive_eq_debug_show_one(struct seq_file *m, struct xive_q *q, u8 prio)
+{
+	int i;
+
+	seq_printf(m, "EQ%d idx=%d T=%d\n", prio, q->idx, q->toggle);
+	if (q->qpage) {
+		for (i = 0; i < q->msk + 1; i++) {
+			if (!(i % 8))
+				seq_printf(m, "%05d ", i);
+			seq_printf(m, "%08x%s", be32_to_cpup(q->qpage + i),
+				   (i + 1) % 8 ? " " : "\n");
+		}
+	}
+	seq_puts(m, "\n");
+}
+
+static int xive_eq_debug_show(struct seq_file *m, void *private)
+{
+	int cpu = (long)m->private;
+	struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
+
+	if (xc)
+		xive_eq_debug_show_one(m, &xc->queue[xive_irq_priority],
+				       xive_irq_priority);
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(xive_eq_debug);
+
+static void xive_core_debugfs_create(void)
+{
+	struct dentry *xive_dir;
+	struct dentry *xive_eq_dir;
+	long cpu;
+	char name[16];
+
+	xive_dir = debugfs_create_dir("xive", arch_debugfs_dir);
+	if (IS_ERR(xive_dir))
+		return;
+
+	debugfs_create_file("ipis", 0400, xive_dir,
+			    NULL, &xive_ipi_debug_fops);
+	debugfs_create_file("interrupts", 0400, xive_dir,
+			    NULL, &xive_irq_debug_fops);
+	xive_eq_dir = debugfs_create_dir("eqs", xive_dir);
+	for_each_possible_cpu(cpu) {
+		snprintf(name, sizeof(name), "cpu%ld", cpu);
+		debugfs_create_file(name, 0400, xive_eq_dir, (void *)cpu,
+				    &xive_eq_debug_fops);
+	}
+	debugfs_create_bool("store-eoi", 0600, xive_dir, &xive_store_eoi);
+
+	if (xive_ops->debug_create)
+		xive_ops->debug_create(xive_dir);
+}
+#else
+static inline void xive_core_debugfs_create(void) { }
+#endif /* CONFIG_DEBUG_FS */
+
+int xive_core_debug_init(void)
+{
+	if (xive_enabled() && IS_ENABLED(CONFIG_DEBUG_FS))
+		xive_core_debugfs_create();
+
+	return 0;
+}