kernel/irq/migration.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #include <linux/irq.h>
   4 #include <linux/interrupt.h>
   5
   6 #include "internals.h"
   7
   8 /**
   9  * irq_fixup_move_pending - Cleanup irq move pending from a dying CPU
  10  * @desc:               Interrupt descpriptor to clean up
  11  * @force_clear:        If set clear the move pending bit unconditionally.
  12  *                      If not set, clear it only when the dying CPU is the
  13  *                      last one in the pending mask.
  14  *
  15  * Returns true if the pending bit was set and the pending mask contains an
  16  * online CPU other than the dying CPU.
  17  */
  18 bool irq_fixup_move_pending(struct irq_desc *desc, bool force_clear)
  19 {
  20         struct irq_data *data = irq_desc_get_irq_data(desc);
  21
  22         if (!irqd_is_setaffinity_pending(data))
  23                 return false;
  24
  25         /*
  26          * The outgoing CPU might be the last online target in a pending
  27          * interrupt move. If that's the case clear the pending move bit.
  28          */
  29         if (cpumask_any_and(desc->pending_mask, cpu_online_mask) >= nr_cpu_ids) {
  30                 irqd_clr_move_pending(data);
  31                 return false;
  32         }
  33         if (force_clear)
  34                 irqd_clr_move_pending(data);
  35         return true;
  36 }
  37
  38 void irq_move_masked_irq(struct irq_data *idata)
  39 {
  40         struct irq_desc *desc = irq_data_to_desc(idata);
  41         struct irq_chip *chip = desc->irq_data.chip;
  42
  43         if (likely(!irqd_is_setaffinity_pending(&desc->irq_data)))
  44                 return;
  45
  46         irqd_clr_move_pending(&desc->irq_data);
  47
  48         /*
  49          * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
  50          */
  51         if (irqd_is_per_cpu(&desc->irq_data)) {
  52                 WARN_ON(1);
  53                 return;
  54         }
  55
  56         if (unlikely(cpumask_empty(desc->pending_mask)))
  57                 return;
  58
  59         if (!chip->irq_set_affinity)
  60                 return;
  61
  62         assert_raw_spin_locked(&desc->lock);
  63
  64         /*
  65          * If there was a valid mask to work with, please
  66          * do the disable, re-program, enable sequence.
  67          * This is *not* particularly important for level triggered
  68          * but in a edge trigger case, we might be setting rte
  69          * when an active trigger is coming in. This could
  70          * cause some ioapics to mal-function.
  71          * Being paranoid i guess!
  72          *
  73          * For correct operation this depends on the caller
  74          * masking the irqs.
  75          */
  76         if (cpumask_any_and(desc->pending_mask, cpu_online_mask) < nr_cpu_ids)
  77                 irq_do_set_affinity(&desc->irq_data, desc->pending_mask, false);
  78
  79         cpumask_clear(desc->pending_mask);
  80 }
  81
  82 void irq_move_irq(struct irq_data *idata)
  83 {
  84         bool masked;
  85
  86         /*
  87          * Get top level irq_data when CONFIG_IRQ_DOMAIN_HIERARCHY is enabled,
  88          * and it should be optimized away when CONFIG_IRQ_DOMAIN_HIERARCHY is
  89          * disabled. So we avoid an "#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY" here.
  90          */
  91         idata = irq_desc_get_irq_data(irq_data_to_desc(idata));
  92
  93         if (likely(!irqd_is_setaffinity_pending(idata)))
  94                 return;
  95
  96         if (unlikely(irqd_irq_disabled(idata)))
  97                 return;
  98
  99         /*
 100          * Be careful vs. already masked interrupts. If this is a
 101          * threaded interrupt with ONESHOT set, we can end up with an
 102          * interrupt storm.
 103          */
 104         masked = irqd_irq_masked(idata);
 105         if (!masked)
 106                 idata->chip->irq_mask(idata);
 107         irq_move_masked_irq(idata);
 108         if (!masked)
 109                 idata->chip->irq_unmask(idata);
 110 }