struct irq_domain *x86_vector_domain;
static DEFINE_RAW_SPINLOCK(vector_lock);
-static cpumask_var_t vector_cpumask, searched_cpumask;
+static cpumask_var_t vector_cpumask, vector_searchmask, searched_cpumask;
static struct irq_chip lapic_controller;
#ifdef CONFIG_X86_IO_APIC
static struct apic_chip_data *legacy_irq_data[NR_IRQS_LEGACY];
*/
static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START;
static int current_offset = VECTOR_OFFSET_START % 16;
- int cpu;
+ int cpu, vector;
- if (d->move_in_progress)
+ /*
+ * If there is still a move in progress or the previous move has not
+ * been cleaned up completely, tell the caller to come back later.
+ */
+ if (d->move_in_progress ||
+ cpumask_intersects(d->old_domain, cpu_online_mask))
return -EBUSY;
/* Only try and allocate irqs on cpus that are present */
cpumask_clear(searched_cpumask);
cpu = cpumask_first_and(mask, cpu_online_mask);
while (cpu < nr_cpu_ids) {
- int new_cpu, vector, offset;
+ int new_cpu, offset;
+ /* Get the possible target cpus for @mask/@cpu from the apic */
apic->vector_allocation_domain(cpu, vector_cpumask, mask);
+ /*
+ * Clear the offline cpus from @vector_cpumask for searching
+ * and verify whether the result overlaps with @mask. If true,
+ * then the call to apic->cpu_mask_to_apicid_and() will
+ * succeed as well. If not, no point in trying to find a
+ * vector in this mask.
+ */
+ cpumask_and(vector_searchmask, vector_cpumask, cpu_online_mask);
+ if (!cpumask_intersects(vector_searchmask, mask))
+ goto next_cpu;
+
if (cpumask_subset(vector_cpumask, d->domain)) {
if (cpumask_equal(vector_cpumask, d->domain))
goto success;
/*
- * New cpumask using the vector is a proper subset of
- * the current in use mask. So cleanup the vector
- * allocation for the members that are not used anymore.
+ * Mark the cpus which are not longer in the mask for
+ * cleanup.
*/
- cpumask_andnot(d->old_domain, d->domain,
- vector_cpumask);
- d->move_in_progress =
- cpumask_intersects(d->old_domain, cpu_online_mask);
- cpumask_and(d->domain, d->domain, vector_cpumask);
- goto success;
+ cpumask_andnot(d->old_domain, d->domain, vector_cpumask);
+ vector = d->cfg.vector;
+ goto update;
}
vector = current_vector;
vector = FIRST_EXTERNAL_VECTOR + offset;
}
- if (unlikely(current_vector == vector)) {
- cpumask_or(searched_cpumask, searched_cpumask,
- vector_cpumask);
- cpumask_andnot(vector_cpumask, mask, searched_cpumask);
- cpu = cpumask_first_and(vector_cpumask,
- cpu_online_mask);
- continue;
- }
+ /* If the search wrapped around, try the next cpu */
+ if (unlikely(current_vector == vector))
+ goto next_cpu;
if (test_bit(vector, used_vectors))
goto next;
- for_each_cpu_and(new_cpu, vector_cpumask, cpu_online_mask) {
+ for_each_cpu(new_cpu, vector_searchmask) {
if (!IS_ERR_OR_NULL(per_cpu(vector_irq, new_cpu)[vector]))
goto next;
}
/* Found one! */
current_vector = vector;
current_offset = offset;
- if (d->cfg.vector) {
+ /* Schedule the old vector for cleanup on all cpus */
+ if (d->cfg.vector)
cpumask_copy(d->old_domain, d->domain);
- d->move_in_progress =
- cpumask_intersects(d->old_domain, cpu_online_mask);
- }
- for_each_cpu_and(new_cpu, vector_cpumask, cpu_online_mask)
+ for_each_cpu(new_cpu, vector_searchmask)
per_cpu(vector_irq, new_cpu)[vector] = irq_to_desc(irq);
- d->cfg.vector = vector;
- cpumask_copy(d->domain, vector_cpumask);
- goto success;
+ goto update;
+
+next_cpu:
+ /*
+ * We exclude the current @vector_cpumask from the requested
+ * @mask and try again with the next online cpu in the
+ * result. We cannot modify @mask, so we use @vector_cpumask
+ * as a temporary buffer here as it will be reassigned when
+ * calling apic->vector_allocation_domain() above.
+ */
+ cpumask_or(searched_cpumask, searched_cpumask, vector_cpumask);
+ cpumask_andnot(vector_cpumask, mask, searched_cpumask);
+ cpu = cpumask_first_and(vector_cpumask, cpu_online_mask);
+ continue;
}
return -ENOSPC;
+update:
+ /*
+ * Exclude offline cpus from the cleanup mask and set the
+ * move_in_progress flag when the result is not empty.
+ */
+ cpumask_and(d->old_domain, d->old_domain, cpu_online_mask);
+ d->move_in_progress = !cpumask_empty(d->old_domain);
+ d->cfg.vector = vector;
+ cpumask_copy(d->domain, vector_cpumask);
success:
- /* cache destination APIC IDs into cfg->dest_apicid */
- return apic->cpu_mask_to_apicid_and(mask, d->domain, &d->cfg.dest_apicid);
+ /*
+ * Cache destination APIC IDs into cfg->dest_apicid. This cannot fail
+ * as we already established, that mask & d->domain & cpu_online_mask
+ * is not empty.
+ */
+ BUG_ON(apic->cpu_mask_to_apicid_and(mask, d->domain,
+ &d->cfg.dest_apicid));
+ return 0;
}
static int assign_irq_vector(int irq, struct apic_chip_data *data,
data->cfg.vector = 0;
cpumask_clear(data->domain);
- if (likely(!data->move_in_progress))
+ /*
+ * If move is in progress or the old_domain mask is not empty,
+ * i.e. the cleanup IPI has not been processed yet, we need to remove
+ * the old references to desc from all cpus vector tables.
+ */
+ if (!data->move_in_progress && cpumask_empty(data->old_domain))
return;
desc = irq_to_desc(irq);
arch_init_htirq_domain(x86_vector_domain);
BUG_ON(!alloc_cpumask_var(&vector_cpumask, GFP_KERNEL));
+ BUG_ON(!alloc_cpumask_var(&vector_searchmask, GFP_KERNEL));
BUG_ON(!alloc_cpumask_var(&searched_cpumask, GFP_KERNEL));
return arch_early_ioapic_init();
return -EINVAL;
err = assign_irq_vector(irq, data, dest);
- if (err) {
- if (assign_irq_vector(irq, data,
- irq_data_get_affinity_mask(irq_data)))
- pr_err("Failed to recover vector for irq %d\n", irq);
- return err;
- }
-
- return IRQ_SET_MASK_OK;
+ return err ? err : IRQ_SET_MASK_OK;
}
static struct irq_chip lapic_controller = {
#ifdef CONFIG_SMP
static void __send_cleanup_vector(struct apic_chip_data *data)
{
- cpumask_var_t cleanup_mask;
-
- if (unlikely(!alloc_cpumask_var(&cleanup_mask, GFP_ATOMIC))) {
- unsigned int i;
-
- for_each_cpu_and(i, data->old_domain, cpu_online_mask)
- apic->send_IPI_mask(cpumask_of(i),
- IRQ_MOVE_CLEANUP_VECTOR);
- } else {
- cpumask_and(cleanup_mask, data->old_domain, cpu_online_mask);
- apic->send_IPI_mask(cleanup_mask, IRQ_MOVE_CLEANUP_VECTOR);
- free_cpumask_var(cleanup_mask);
- }
+ raw_spin_lock(&vector_lock);
+ cpumask_and(data->old_domain, data->old_domain, cpu_online_mask);
data->move_in_progress = 0;
+ if (!cpumask_empty(data->old_domain))
+ apic->send_IPI_mask(data->old_domain, IRQ_MOVE_CLEANUP_VECTOR);
+ raw_spin_unlock(&vector_lock);
}
void send_cleanup_vector(struct irq_cfg *cfg)
goto unlock;
/*
- * Check if the irq migration is in progress. If so, we
- * haven't received the cleanup request yet for this irq.
+ * Nothing to cleanup if irq migration is in progress
+ * or this cpu is not set in the cleanup mask.
*/
- if (data->move_in_progress)
+ if (data->move_in_progress ||
+ !cpumask_test_cpu(me, data->old_domain))
goto unlock;
+ /*
+ * We have two cases to handle here:
+ * 1) vector is unchanged but the target mask got reduced
+ * 2) vector and the target mask has changed
+ *
+ * #1 is obvious, but in #2 we have two vectors with the same
+ * irq descriptor: the old and the new vector. So we need to
+ * make sure that we only cleanup the old vector. The new
+ * vector has the current @vector number in the config and
+ * this cpu is part of the target mask. We better leave that
+ * one alone.
+ */
if (vector == data->cfg.vector &&
cpumask_test_cpu(me, data->domain))
goto unlock;
goto unlock;
}
__this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
+ cpumask_clear_cpu(me, data->old_domain);
unlock:
raw_spin_unlock(&desc->lock);
}
__irq_complete_move(cfg, ~get_irq_regs()->orig_ax);
}
-void irq_force_complete_move(int irq)
+/*
+ * Called with @desc->lock held and interrupts disabled.
+ */
+void irq_force_complete_move(struct irq_desc *desc)
{
- struct irq_cfg *cfg = irq_cfg(irq);
+ struct irq_data *irqdata = irq_desc_get_irq_data(desc);
+ struct apic_chip_data *data = apic_chip_data(irqdata);
+ struct irq_cfg *cfg = data ? &data->cfg : NULL;
+
+ if (!cfg)
+ return;
- if (cfg)
- __irq_complete_move(cfg, cfg->vector);
+ __irq_complete_move(cfg, cfg->vector);
+
+ /*
+ * This is tricky. If the cleanup of @data->old_domain has not been
+ * done yet, then the following setaffinity call will fail with
+ * -EBUSY. This can leave the interrupt in a stale state.
+ *
+ * The cleanup cannot make progress because we hold @desc->lock. So in
+ * case @data->old_domain is not yet cleaned up, we need to drop the
+ * lock and acquire it again. @desc cannot go away, because the
+ * hotplug code holds the sparse irq lock.
+ */
+ raw_spin_lock(&vector_lock);
+ /* Clean out all offline cpus (including ourself) first. */
+ cpumask_and(data->old_domain, data->old_domain, cpu_online_mask);
+ while (!cpumask_empty(data->old_domain)) {
+ raw_spin_unlock(&vector_lock);
+ raw_spin_unlock(&desc->lock);
+ cpu_relax();
+ raw_spin_lock(&desc->lock);
+ /*
+ * Reevaluate apic_chip_data. It might have been cleared after
+ * we dropped @desc->lock.
+ */
+ data = apic_chip_data(irqdata);
+ if (!data)
+ return;
+ raw_spin_lock(&vector_lock);
+ }
+ raw_spin_unlock(&vector_lock);
}
#endif
projects / firefly-linux-kernel-4.4.55.git / blobdiff