--- /dev/null
+/*
+ * Copyright 2016,2017 IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "xive: " fmt
+
+#include <linux/types.h>
+#include <linux/threads.h>
+#include <linux/kernel.h>
+#include <linux/irq.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 <asm/prom.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(fmt)
+#else
+#define DBG_VERBOSE(fmt...) do { } while(0)
+#endif
+
+bool __xive_enabled;
+bool xive_cmdline_disabled;
+
+/* We use only one priority for now */
+static u8 xive_irq_priority;
+
+/* TIMA */
+void __iomem *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 all use the same logical irq number */
+static u32 xive_ipi_irq;
+#endif
+
+/* Xive state for each CPU */
+static DEFINE_PER_CPU(struct xive_cpu *, xive_cpu);
+
+/*
+ * A "disabled" interrupt should never fire, to catch problems
+ * we set its logical number to this
+ */
+#define XIVE_BAD_IRQ 0x7fffffff
+#define XIVE_MAX_IRQ (XIVE_BAD_IRQ - 1)
+
+/* An invalid CPU target */
+#define XIVE_INVALID_TARGET (-1)
+
+/*
+ * 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;
+
+ /* 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)
+ break;
+
+ /* 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.h
+ */
+static u8 xive_poke_esb(struct xive_irq_data *xd, u32 offset)
+{
+ u64 val;
+
+ /* Handle HW errata */
+ if (xd->flags & XIVE_IRQ_FLAG_SHIFT_BUG)
+ offset |= offset << 4;
+
+ val = in_be64(xd->eoi_mmio + offset);
+
+ return (u8)val;
+}
+
+#ifdef CONFIG_XMON
+static 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 Q T=%d %08x %08x ...\n", name,
+ q->toggle, i0, i1);
+}
+
+void xmon_xive_do_dump(int cpu)
+{
+ struct xive_cpu *xc = per_cpu(xive_cpu, cpu);
+
+ xmon_printf("XIVE state for CPU %d:\n", cpu);
+ xmon_printf(" pp=%02x cppr=%02x\n", xc->pending_prio, xc->cppr);
+ xive_dump_eq("IRQ", &xc->queue[xive_irq_priority]);
+#ifdef CONFIG_SMP
+ {
+ u64 val = xive_poke_esb(&xc->ipi_data, XIVE_ESB_GET);
+ xmon_printf(" IPI state: %x:%c%c\n", xc->hw_ipi,
+ val & XIVE_ESB_VAL_P ? 'P' : 'p',
+ val & XIVE_ESB_VAL_P ? 'Q' : 'q');
+ }
+#endif
+}
+#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 differenciate 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
+ */
+void xive_do_source_eoi(u32 hw_irq, struct xive_irq_data *xd)
+{
+ /* If the XIVE supports the new "store EOI facility, use it */
+ if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
+ out_be64(xd->eoi_mmio, 0);
+ else if (hw_irq && xd->flags & XIVE_IRQ_FLAG_EOI_FW) {
+ /*
+ * The FW told us to call it. This happens for some
+ * interrupt sources that need additional HW whacking
+ * beyond the ESB manipulation. For example LPC interrupts
+ * on P9 DD1.0 need a latch to be clared in the LPC bridge
+ * itself. The Firmware will take care of it.
+ */
+ if (WARN_ON_ONCE(!xive_ops->eoi))
+ return;
+ xive_ops->eoi(hw_irq);
+ } else {
+ u8 eoi_val;
+
+ /*
+ * Otherwise for EOI, we use the special MMIO that does
+ * a clear of both P and Q and returns the old Q,
+ * except for LSIs where we use the "EOI cycle" special
+ * load.
+ *
+ * This allows us to then do a re-trigger if Q was set
+ * rather than synthesizing an interrupt in software
+ *
+ * For LSIs, using the HW EOI cycle works around a problem
+ * on P9 DD1 PHBs where the other ESB accesses don't work
+ * properly.
+ */
+ if (xd->flags & XIVE_IRQ_FLAG_LSI)
+ in_be64(xd->eoi_mmio);
+ else {
+ eoi_val = xive_poke_esb(xd, XIVE_ESB_SET_PQ_00);
+ DBG_VERBOSE("eoi_val=%x\n", offset, 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 */
+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 */
+ if (!irqd_irq_disabled(d))
+ xive_do_source_eoi(irqd_to_hwirq(d), xd);
+
+ /*
+ * 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. This
+ * is only called for normal interrupts that do not require
+ * masking/unmasking via firmware.
+ */
+static void xive_do_source_set_mask(struct xive_irq_data *xd,
+ bool mask)
+{
+ u64 val;
+
+ /*
+ * 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_poke_esb(xd, XIVE_ESB_SET_PQ_01);
+ xd->saved_p = !!(val & XIVE_ESB_VAL_P);
+ } else if (xd->saved_p)
+ xive_poke_esb(xd, XIVE_ESB_SET_PQ_10);
+ else
+ xive_poke_esb(xd, XIVE_ESB_SET_PQ_00);
+}
+
+/*
+ * 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 (unlikely(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 = cpumask_weight(mask);
+ 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.
+ */
+ for (;;) {
+ /*
+ * 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);
+ if (cpu == first)
+ break;
+ /* Wrap around */
+ if (cpu >= nr_cpu_ids)
+ cpu = cpumask_first(mask);
+ }
+ 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;
+
+ pr_devel("xive_irq_startup: irq %d [0x%x] data @%p\n",
+ d->irq, hw_irq, d);
+
+#ifdef CONFIG_PCI_MSI
+ /*
+ * The generic MSI code returns with the interrupt disabled on the
+ * card, using the MSI mask bits. Firmware doesn't appear to unmask
+ * at that level, so we do it here by hand.
+ */
+ if (irq_data_get_msi_desc(d))
+ pci_msi_unmask_irq(d);
+#endif
+
+ /* 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;
+}
+
+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_devel("xive_irq_shutdown: irq %d [0x%x] data @%p\n",
+ 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);
+
+ /*
+ * The above may have set saved_p. We clear it otherwise it
+ * will prevent re-enabling later on. It is ok to forget the
+ * fact that the interrupt might be in a queue because we are
+ * accounting that already in xive_dec_target_count() and will
+ * be re-routing it to a new queue with proper accounting when
+ * it's started up again
+ */
+ xd->saved_p = false;
+
+ /*
+ * 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_devel("xive_irq_unmask: irq %d data @%p\n", d->irq, xd);
+
+ /*
+ * This is a workaround for PCI LSI problems on P9, for
+ * these, we call FW to set the mask. The problems might
+ * be fixed by P9 DD2.0, if that is the case, firmware
+ * will no longer set that flag.
+ */
+ if (xd->flags & XIVE_IRQ_FLAG_MASK_FW) {
+ unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+ xive_ops->configure_irq(hw_irq,
+ get_hard_smp_processor_id(xd->target),
+ xive_irq_priority, d->irq);
+ return;
+ }
+
+ 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_devel("xive_irq_mask: irq %d data @%p\n", d->irq, xd);
+
+ /*
+ * This is a workaround for PCI LSI problems on P9, for
+ * these, we call OPAL to set the mask. The problems might
+ * be fixed by P9 DD2.0, if that is the case, firmware
+ * will no longer set that flag.
+ */
+ if (xd->flags & XIVE_IRQ_FLAG_MASK_FW) {
+ unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+ xive_ops->configure_irq(hw_irq,
+ get_hard_smp_processor_id(xd->target),
+ 0xff, d->irq);
+ return;
+ }
+
+ 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_devel("xive_irq_set_affinity: irq %d\n", d->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;
+
+ 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_devel(" 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 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_poke_esb(xd, XIVE_ESB_SET_PQ_11);
+
+ /*
+ * Note: We pass "0" to the hw_irq argument in order to
+ * avoid calling into the backend EOI code which we don't
+ * want to do in the case of a re-trigger. Backends typically
+ * only do EOI for LSIs anyway.
+ */
+ xive_do_source_eoi(0, xd);
+
+ return 1;
+}
+
+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,
+};
+
+bool is_xive_irq(struct irq_chip *chip)
+{
+ return chip == &xive_irq_chip;
+}
+
+void xive_cleanup_irq_data(struct xive_irq_data *xd)
+{
+ 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;
+ }
+}
+
+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);
+
+ return 0;
+}
+
+static 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);
+}
+
+#ifdef CONFIG_SMP
+
+static void xive_cause_ipi(int cpu, unsigned long msg)
+{
+ struct xive_cpu *xc;
+ struct xive_irq_data *xd;
+
+ xc = per_cpu(xive_cpu, cpu);
+
+ DBG_VERBOSE("IPI msg#%ld CPU %d -> %d (HW IRQ 0x%x)\n",
+ msg, 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;
+ xive_do_source_eoi(xc->hw_ipi, &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,
+};
+
+static void __init xive_request_ipi(void)
+{
+ unsigned int virq;
+
+ /*
+ * Initialization failed, move on, we might manage to
+ * reach the point where we display our errors before
+ * the system falls appart
+ */
+ if (!xive_irq_domain)
+ return;
+
+ /* Initialize it */
+ virq = irq_create_mapping(xive_irq_domain, 0);
+ xive_ipi_irq = virq;
+
+ WARN_ON(request_irq(virq, xive_muxed_ipi_action,
+ IRQF_PERCPU | IRQF_NO_THREAD, "IPI", NULL));
+}
+
+static int xive_setup_cpu_ipi(unsigned int 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 != 0)
+ return 0;
+
+ /* 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_devel("CPU %d HW IPI %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;
+}
+
+static void xive_cleanup_cpu_ipi(unsigned int cpu, struct xive_cpu *xc)
+{
+ /* Disable the IPI and free the IRQ data */
+
+ /* Already cleaned up ? */
+ if (xc->hw_ipi == 0)
+ return;
+
+ /* 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_request_ipi();
+
+ /* 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);
+
+#ifdef CONFIG_SMP
+ /* IPIs are special and come up with HW number 0 */
+ if (hw == 0) {
+ /*
+ * IPIs are marked per-cpu. We use separate HW interrupts under
+ * the hood but associated with the same "linux" interrupt
+ */
+ irq_set_chip_and_handler(virq, &xive_ipi_chip,
+ handle_percpu_irq);
+ return 0;
+ }
+#endif
+
+ 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)
+{
+ struct irq_data *data = irq_get_irq_data(virq);
+ unsigned int hw_irq;
+
+ /* XXX Assign BAD number */
+ if (!data)
+ return;
+ hw_irq = (unsigned int)irqd_to_hwirq(data);
+ if (hw_irq)
+ 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);
+}
+
+static const struct irq_domain_ops xive_irq_domain_ops = {
+ .match = xive_irq_domain_match,
+ .map = xive_irq_domain_map,
+ .unmap = xive_irq_domain_unmap,
+ .xlate = xive_irq_domain_xlate,
+};
+
+static void __init xive_init_host(void)
+{
+ xive_irq_domain = irq_domain_add_nomap(NULL, XIVE_MAX_IRQ,
+ &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) {
+ struct device_node *np;
+
+ xc = kzalloc_node(sizeof(struct xive_cpu),
+ GFP_KERNEL, cpu_to_node(cpu));
+ if (!xc)
+ return -ENOMEM;
+ np = of_get_cpu_node(cpu, NULL);
+ if (np)
+ xc->chip_id = of_get_ibm_chip_id(np);
+ of_node_put(np);
+
+ 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);
+
+ /* Debug: Dump the TM state */
+ pr_devel("CPU %d [HW 0x%02x] VT=%02x\n",
+ smp_processor_id(), hard_smp_processor_id(),
+ in_8(xive_tima + xive_tima_offset + TM_WORD2));
+
+ /* 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_devel("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;
+ unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+
+ /*
+ * Ignore anything that isn't a XIVE irq and ignore
+ * IPIs, so can just be dropped.
+ */
+ if (d->domain != xive_irq_domain || hw_irq == 0)
+ 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);
+
+ /*
+ * 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(irqd_to_hwirq(d), 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 */
+
+void xive_kexec_teardown_cpu(int secondary)
+{
+ 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);
+
+ /* Backend cleanup if any */
+ 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 xive_core_init(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_devel("Initializing host..\n");
+ xive_init_host();
+
+ pr_devel("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 intialized with %s backend\n",
+ xive_ops->name);
+ pr_info("Using priority %d for all interrupts\n", max_prio);
+
+ return true;
+}
+
+static int __init xive_off(char *arg)
+{
+ xive_cmdline_disabled = true;
+ return 0;
+}
+__setup("xive=off", xive_off);
--- /dev/null
+/*
+ * Copyright 2016,2017 IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "xive: " fmt
+
+#include <linux/types.h>
+#include <linux/irq.h>
+#include <linux/debugfs.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/seq_file.h>
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/delay.h>
+#include <linux/cpumask.h>
+#include <linux/mm.h>
+
+#include <asm/prom.h>
+#include <asm/io.h>
+#include <asm/smp.h>
+#include <asm/irq.h>
+#include <asm/errno.h>
+#include <asm/xive.h>
+#include <asm/xive-regs.h>
+#include <asm/opal.h>
+
+#include "xive-internal.h"
+
+
+static u32 xive_provision_size;
+static u32 *xive_provision_chips;
+static u32 xive_provision_chip_count;
+static u32 xive_queue_shift;
+static u32 xive_pool_vps = XIVE_INVALID_VP;
+static struct kmem_cache *xive_provision_cache;
+
+int xive_native_populate_irq_data(u32 hw_irq, struct xive_irq_data *data)
+{
+ __be64 flags, eoi_page, trig_page;
+ __be32 esb_shift, src_chip;
+ u64 opal_flags;
+ s64 rc;
+
+ memset(data, 0, sizeof(*data));
+
+ rc = opal_xive_get_irq_info(hw_irq, &flags, &eoi_page, &trig_page,
+ &esb_shift, &src_chip);
+ if (rc) {
+ pr_err("opal_xive_get_irq_info(0x%x) returned %lld\n",
+ hw_irq, rc);
+ return -EINVAL;
+ }
+
+ opal_flags = be64_to_cpu(flags);
+ if (opal_flags & OPAL_XIVE_IRQ_STORE_EOI)
+ data->flags |= XIVE_IRQ_FLAG_STORE_EOI;
+ if (opal_flags & OPAL_XIVE_IRQ_LSI)
+ data->flags |= XIVE_IRQ_FLAG_LSI;
+ if (opal_flags & OPAL_XIVE_IRQ_SHIFT_BUG)
+ data->flags |= XIVE_IRQ_FLAG_SHIFT_BUG;
+ if (opal_flags & OPAL_XIVE_IRQ_MASK_VIA_FW)
+ data->flags |= XIVE_IRQ_FLAG_MASK_FW;
+ if (opal_flags & OPAL_XIVE_IRQ_EOI_VIA_FW)
+ data->flags |= XIVE_IRQ_FLAG_EOI_FW;
+ data->eoi_page = be64_to_cpu(eoi_page);
+ data->trig_page = be64_to_cpu(trig_page);
+ data->esb_shift = be32_to_cpu(esb_shift);
+ data->src_chip = be32_to_cpu(src_chip);
+
+ data->eoi_mmio = ioremap(data->eoi_page, 1u << data->esb_shift);
+ if (!data->eoi_mmio) {
+ pr_err("Failed to map EOI page for irq 0x%x\n", hw_irq);
+ return -ENOMEM;
+ }
+
+ if (!data->trig_page)
+ return 0;
+ if (data->trig_page == data->eoi_page) {
+ data->trig_mmio = data->eoi_mmio;
+ return 0;
+ }
+
+ data->trig_mmio = ioremap(data->trig_page, 1u << data->esb_shift);
+ if (!data->trig_mmio) {
+ pr_err("Failed to map trigger page for irq 0x%x\n", hw_irq);
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+int xive_native_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 sw_irq)
+{
+ s64 rc;
+
+ for (;;) {
+ rc = opal_xive_set_irq_config(hw_irq, target, prio, sw_irq);
+ if (rc != OPAL_BUSY)
+ break;
+ msleep(1);
+ }
+ return rc == 0 ? 0 : -ENXIO;
+}
+
+/* This can be called multiple time to change a queue configuration */
+int xive_native_configure_queue(u32 vp_id, struct xive_q *q, u8 prio,
+ __be32 *qpage, u32 order, bool can_escalate)
+{
+ s64 rc = 0;
+ __be64 qeoi_page_be;
+ __be32 esc_irq_be;
+ u64 flags, qpage_phys;
+
+ /* If there's an actual queue page, clean it */
+ if (order) {
+ if (WARN_ON(!qpage))
+ return -EINVAL;
+ qpage_phys = __pa(qpage);
+ } else
+ qpage_phys = 0;
+
+ /* Initialize the rest of the fields */
+ q->msk = order ? ((1u << (order - 2)) - 1) : 0;
+ q->idx = 0;
+ q->toggle = 0;
+
+ rc = opal_xive_get_queue_info(vp_id, prio, NULL, NULL,
+ &qeoi_page_be,
+ &esc_irq_be,
+ NULL);
+ if (rc) {
+ pr_err("Error %lld getting queue info prio %d\n", rc, prio);
+ rc = -EIO;
+ goto fail;
+ }
+ q->eoi_phys = be64_to_cpu(qeoi_page_be);
+
+ /* Default flags */
+ flags = OPAL_XIVE_EQ_ALWAYS_NOTIFY | OPAL_XIVE_EQ_ENABLED;
+
+ /* Escalation needed ? */
+ if (can_escalate) {
+ q->esc_irq = be32_to_cpu(esc_irq_be);
+ flags |= OPAL_XIVE_EQ_ESCALATE;
+ }
+
+ /* Configure and enable the queue in HW */
+ for (;;) {
+ rc = opal_xive_set_queue_info(vp_id, prio, qpage_phys, order, flags);
+ if (rc != OPAL_BUSY)
+ break;
+ msleep(1);
+ }
+ if (rc) {
+ pr_err("Error %lld setting queue for prio %d\n", rc, prio);
+ rc = -EIO;
+ } else {
+ /*
+ * KVM code requires all of the above to be visible before
+ * q->qpage is set due to how it manages IPI EOIs
+ */
+ wmb();
+ q->qpage = qpage;
+ }
+fail:
+ return rc;
+}
+
+static void __xive_native_disable_queue(u32 vp_id, struct xive_q *q, u8 prio)
+{
+ s64 rc;
+
+ /* Disable the queue in HW */
+ for (;;) {
+ rc = opal_xive_set_queue_info(vp_id, prio, 0, 0, 0);
+ break;
+ msleep(1);
+ }
+ if (rc)
+ pr_err("Error %lld disabling queue for prio %d\n", rc, prio);
+}
+
+void xive_native_disable_queue(u32 vp_id, struct xive_q *q, u8 prio)
+{
+ __xive_native_disable_queue(vp_id, q, prio);
+}
+
+static int xive_native_setup_queue(unsigned int cpu, struct xive_cpu *xc, u8 prio)
+{
+ struct xive_q *q = &xc->queue[prio];
+ unsigned int alloc_order;
+ struct page *pages;
+ __be32 *qpage;
+
+ alloc_order = (xive_queue_shift > PAGE_SHIFT) ?
+ (xive_queue_shift - PAGE_SHIFT) : 0;
+ pages = alloc_pages_node(cpu_to_node(cpu), GFP_KERNEL, alloc_order);
+ if (!pages)
+ return -ENOMEM;
+ qpage = (__be32 *)page_address(pages);
+ memset(qpage, 0, 1 << xive_queue_shift);
+ return xive_native_configure_queue(get_hard_smp_processor_id(cpu),
+ q, prio, qpage, xive_queue_shift, false);
+}
+
+static void xive_native_cleanup_queue(unsigned int cpu, struct xive_cpu *xc, u8 prio)
+{
+ struct xive_q *q = &xc->queue[prio];
+ unsigned int alloc_order;
+
+ /*
+ * We use the variant with no iounmap as this is called on exec
+ * from an IPI and iounmap isn't safe
+ */
+ __xive_native_disable_queue(get_hard_smp_processor_id(cpu), q, prio);
+ alloc_order = (xive_queue_shift > PAGE_SHIFT) ?
+ (xive_queue_shift - PAGE_SHIFT) : 0;
+ free_pages((unsigned long)q->qpage, alloc_order);
+ q->qpage = NULL;
+}
+
+static bool xive_native_match(struct device_node *node)
+{
+ return of_device_is_compatible(node, "ibm,opal-xive-vc");
+}
+
+#ifdef CONFIG_SMP
+static int xive_native_get_ipi(unsigned int cpu, struct xive_cpu *xc)
+{
+ struct device_node *np;
+ unsigned int chip_id;
+ s64 irq;
+
+ /* Find the chip ID */
+ np = of_get_cpu_node(cpu, NULL);
+ if (np) {
+ if (of_property_read_u32(np, "ibm,chip-id", &chip_id) < 0)
+ chip_id = 0;
+ }
+
+ /* Allocate an IPI and populate info about it */
+ for (;;) {
+ irq = opal_xive_allocate_irq(chip_id);
+ if (irq == OPAL_BUSY) {
+ msleep(1);
+ continue;
+ }
+ if (irq < 0) {
+ pr_err("Failed to allocate IPI on CPU %d\n", cpu);
+ return -ENXIO;
+ }
+ xc->hw_ipi = irq;
+ break;
+ }
+ return 0;
+}
+
+u32 xive_native_alloc_irq(void)
+{
+ s64 rc;
+
+ for (;;) {
+ rc = opal_xive_allocate_irq(OPAL_XIVE_ANY_CHIP);
+ if (rc != OPAL_BUSY)
+ break;
+ msleep(1);
+ }
+ if (rc < 0)
+ return 0;
+ return rc;
+}
+
+void xive_native_free_irq(u32 irq)
+{
+ for (;;) {
+ s64 rc = opal_xive_free_irq(irq);
+ if (rc != OPAL_BUSY)
+ break;
+ msleep(1);
+ }
+}
+
+static void xive_native_put_ipi(unsigned int cpu, struct xive_cpu *xc)
+{
+ s64 rc;
+
+ /* Free the IPI */
+ if (!xc->hw_ipi)
+ return;
+ for (;;) {
+ rc = opal_xive_free_irq(xc->hw_ipi);
+ if (rc == OPAL_BUSY) {
+ msleep(1);
+ continue;
+ }
+ xc->hw_ipi = 0;
+ break;
+ }
+}
+#endif /* CONFIG_SMP */
+
+static void xive_native_shutdown(void)
+{
+ /* Switch the XIVE to emulation mode */
+ opal_xive_reset(OPAL_XIVE_MODE_EMU);
+}
+
+/*
+ * Perform an "ack" cycle on the current thread, thus
+ * grabbing the pending active priorities and updating
+ * the CPPR to the most favored one.
+ */
+static void xive_native_update_pending(struct xive_cpu *xc)
+{
+ u8 he, cppr;
+ u16 ack;
+
+ /* Perform the acknowledge hypervisor to register cycle */
+ ack = be16_to_cpu(__raw_readw(xive_tima + TM_SPC_ACK_HV_REG));
+
+ /* Synchronize subsequent queue accesses */
+ mb();
+
+ /*
+ * Grab the CPPR and the "HE" field which indicates the source
+ * of the hypervisor interrupt (if any)
+ */
+ cppr = ack & 0xff;
+ he = GETFIELD(TM_QW3_NSR_HE, (ack >> 8));
+ switch(he) {
+ case TM_QW3_NSR_HE_NONE: /* Nothing to see here */
+ break;
+ case TM_QW3_NSR_HE_PHYS: /* Physical thread interrupt */
+ if (cppr == 0xff)
+ return;
+ /* Mark the priority pending */
+ xc->pending_prio |= 1 << cppr;
+
+ /*
+ * A new interrupt should never have a CPPR less favored
+ * than our current one.
+ */
+ if (cppr >= xc->cppr)
+ pr_err("CPU %d odd ack CPPR, got %d at %d\n",
+ smp_processor_id(), cppr, xc->cppr);
+
+ /* Update our idea of what the CPPR is */
+ xc->cppr = cppr;
+ break;
+ case TM_QW3_NSR_HE_POOL: /* HV Pool interrupt (unused) */
+ case TM_QW3_NSR_HE_LSI: /* Legacy FW LSI (unused) */
+ pr_err("CPU %d got unexpected interrupt type HE=%d\n",
+ smp_processor_id(), he);
+ return;
+ }
+}
+
+static void xive_native_eoi(u32 hw_irq)
+{
+ /*
+ * Not normally used except if specific interrupts need
+ * a workaround on EOI.
+ */
+ opal_int_eoi(hw_irq);
+}
+
+static void xive_native_setup_cpu(unsigned int cpu, struct xive_cpu *xc)
+{
+ s64 rc;
+ u32 vp;
+ __be64 vp_cam_be;
+ u64 vp_cam;
+
+ if (xive_pool_vps == XIVE_INVALID_VP)
+ return;
+
+ /* Enable the pool VP */
+ vp = xive_pool_vps + get_hard_smp_processor_id(cpu);
+ pr_debug("CPU %d setting up pool VP 0x%x\n", cpu, vp);
+ for (;;) {
+ rc = opal_xive_set_vp_info(vp, OPAL_XIVE_VP_ENABLED, 0);
+ if (rc != OPAL_BUSY)
+ break;
+ msleep(1);
+ }
+ if (rc) {
+ pr_err("Failed to enable pool VP on CPU %d\n", cpu);
+ return;
+ }
+
+ /* Grab it's CAM value */
+ rc = opal_xive_get_vp_info(vp, NULL, &vp_cam_be, NULL, NULL);
+ if (rc) {
+ pr_err("Failed to get pool VP info CPU %d\n", cpu);
+ return;
+ }
+ vp_cam = be64_to_cpu(vp_cam_be);
+
+ pr_debug("VP CAM = %llx\n", vp_cam);
+
+ /* Push it on the CPU (set LSMFB to 0xff to skip backlog scan) */
+ pr_debug("(Old HW value: %08x)\n",
+ in_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD2));
+ out_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD0, 0xff);
+ out_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD2,
+ TM_QW2W2_VP | vp_cam);
+ pr_debug("(New HW value: %08x)\n",
+ in_be32(xive_tima + TM_QW2_HV_POOL + TM_WORD2));
+}
+
+static void xive_native_teardown_cpu(unsigned int cpu, struct xive_cpu *xc)
+{
+ s64 rc;
+ u32 vp;
+
+ if (xive_pool_vps == XIVE_INVALID_VP)
+ return;
+
+ /* Pull the pool VP from the CPU */
+ in_be64(xive_tima + TM_SPC_PULL_POOL_CTX);
+
+ /* Disable it */
+ vp = xive_pool_vps + get_hard_smp_processor_id(cpu);
+ for (;;) {
+ rc = opal_xive_set_vp_info(vp, 0, 0);
+ if (rc != OPAL_BUSY)
+ break;
+ msleep(1);
+ }
+}
+
+static void xive_native_sync_source(u32 hw_irq)
+{
+ opal_xive_sync(XIVE_SYNC_EAS, hw_irq);
+}
+
+static const struct xive_ops xive_native_ops = {
+ .populate_irq_data = xive_native_populate_irq_data,
+ .configure_irq = xive_native_configure_irq,
+ .setup_queue = xive_native_setup_queue,
+ .cleanup_queue = xive_native_cleanup_queue,
+ .match = xive_native_match,
+ .shutdown = xive_native_shutdown,
+ .update_pending = xive_native_update_pending,
+ .eoi = xive_native_eoi,
+ .setup_cpu = xive_native_setup_cpu,
+ .teardown_cpu = xive_native_teardown_cpu,
+ .sync_source = xive_native_sync_source,
+#ifdef CONFIG_SMP
+ .get_ipi = xive_native_get_ipi,
+ .put_ipi = xive_native_put_ipi,
+#endif /* CONFIG_SMP */
+ .name = "native",
+};
+
+static bool xive_parse_provisioning(struct device_node *np)
+{
+ int rc;
+
+ if (of_property_read_u32(np, "ibm,xive-provision-page-size",
+ &xive_provision_size) < 0)
+ return true;
+ rc = of_property_count_elems_of_size(np, "ibm,xive-provision-chips", 4);
+ if (rc < 0) {
+ pr_err("Error %d getting provision chips array\n", rc);
+ return false;
+ }
+ xive_provision_chip_count = rc;
+ if (rc == 0)
+ return true;
+
+ xive_provision_chips = kzalloc(4 * xive_provision_chip_count,
+ GFP_KERNEL);
+ if (WARN_ON(!xive_provision_chips))
+ return false;
+
+ rc = of_property_read_u32_array(np, "ibm,xive-provision-chips",
+ xive_provision_chips,
+ xive_provision_chip_count);
+ if (rc < 0) {
+ pr_err("Error %d reading provision chips array\n", rc);
+ return false;
+ }
+
+ xive_provision_cache = kmem_cache_create("xive-provision",
+ xive_provision_size,
+ xive_provision_size,
+ 0, NULL);
+ if (!xive_provision_cache) {
+ pr_err("Failed to allocate provision cache\n");
+ return false;
+ }
+ return true;
+}
+
+u32 xive_native_default_eq_shift(void)
+{
+ return xive_queue_shift;
+}
+
+bool xive_native_init(void)
+{
+ struct device_node *np;
+ struct resource r;
+ void __iomem *tima;
+ struct property *prop;
+ u8 max_prio = 7;
+ const __be32 *p;
+ u32 val;
+ s64 rc;
+
+ if (xive_cmdline_disabled)
+ return false;
+
+ pr_devel("xive_native_init()\n");
+ np = of_find_compatible_node(NULL, NULL, "ibm,opal-xive-pe");
+ if (!np) {
+ pr_devel("not found !\n");
+ return false;
+ }
+ pr_devel("Found %s\n", np->full_name);
+
+ /* Resource 1 is HV window */
+ if (of_address_to_resource(np, 1, &r)) {
+ pr_err("Failed to get thread mgmnt area resource\n");
+ return false;
+ }
+ tima = ioremap(r.start, resource_size(&r));
+ if (!tima) {
+ pr_err("Failed to map thread mgmnt area\n");
+ return false;
+ }
+
+ /* Read number of priorities */
+ if (of_property_read_u32(np, "ibm,xive-#priorities", &val) == 0)
+ max_prio = val - 1;
+
+ /* Iterate the EQ sizes and pick one */
+ of_property_for_each_u32(np, "ibm,xive-eq-sizes", prop, p, val) {
+ xive_queue_shift = val;
+ if (val == PAGE_SHIFT)
+ break;
+ }
+
+ /* Grab size of provisioning pages */
+ xive_parse_provisioning(np);
+
+ /* Switch the XIVE to exploitation mode */
+ rc = opal_xive_reset(OPAL_XIVE_MODE_EXPL);
+ if (rc) {
+ pr_err("Switch to exploitation mode failed with error %lld\n", rc);
+ return false;
+ }
+
+ /* Initialize XIVE core with our backend */
+ if (!xive_core_init(&xive_native_ops, tima, TM_QW3_HV_PHYS,
+ max_prio)) {
+ opal_xive_reset(OPAL_XIVE_MODE_EMU);
+ return false;
+ }
+ pr_info("Using %dkB queues\n", 1 << (xive_queue_shift - 10));
+ return true;
+}
+
+static bool xive_native_provision_pages(void)
+{
+ u32 i;
+ void *p;
+
+ for (i = 0; i < xive_provision_chip_count; i++) {
+ u32 chip = xive_provision_chips[i];
+
+ /*
+ * XXX TODO: Try to make the allocation local to the node where
+ * the chip resides.
+ */
+ p = kmem_cache_alloc(xive_provision_cache, GFP_KERNEL);
+ if (!p) {
+ pr_err("Failed to allocate provisioning page\n");
+ return false;
+ }
+ opal_xive_donate_page(chip, __pa(p));
+ }
+ return true;
+}
+
+u32 xive_native_alloc_vp_block(u32 max_vcpus)
+{
+ s64 rc;
+ u32 order;
+
+ order = fls(max_vcpus) - 1;
+ if (max_vcpus > (1 << order))
+ order++;
+
+ pr_info("VP block alloc, for max VCPUs %d use order %d\n",
+ max_vcpus, order);
+
+ for (;;) {
+ rc = opal_xive_alloc_vp_block(order);
+ switch (rc) {
+ case OPAL_BUSY:
+ msleep(1);
+ break;
+ case OPAL_XIVE_PROVISIONING:
+ if (!xive_native_provision_pages())
+ return XIVE_INVALID_VP;
+ break;
+ default:
+ if (rc < 0) {
+ pr_err("OPAL failed to allocate VCPUs order %d, err %lld\n",
+ order, rc);
+ return XIVE_INVALID_VP;
+ }
+ return rc;
+ }
+ }
+}
+EXPORT_SYMBOL_GPL(xive_native_alloc_vp_block);
+
+void xive_native_free_vp_block(u32 vp_base)
+{
+ s64 rc;
+
+ if (vp_base == XIVE_INVALID_VP)
+ return;
+
+ rc = opal_xive_free_vp_block(vp_base);
+ if (rc < 0)
+ pr_warn("OPAL error %lld freeing VP block\n", rc);
+}
+EXPORT_SYMBOL_GPL(xive_native_free_vp_block);
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff