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-rw-r--r--arch/powerpc/sysdev/xive/common.c1864
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;
+}