cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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migration.c (3150B)

      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 descriptor 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 */
     18bool 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
     38void irq_move_masked_irq(struct irq_data *idata)
     39{
     40	struct irq_desc *desc = irq_data_to_desc(idata);
     41	struct irq_data *data = &desc->irq_data;
     42	struct irq_chip *chip = data->chip;
     43
     44	if (likely(!irqd_is_setaffinity_pending(data)))
     45		return;
     46
     47	irqd_clr_move_pending(data);
     48
     49	/*
     50	 * Paranoia: cpu-local interrupts shouldn't be calling in here anyway.
     51	 */
     52	if (irqd_is_per_cpu(data)) {
     53		WARN_ON(1);
     54		return;
     55	}
     56
     57	if (unlikely(cpumask_empty(desc->pending_mask)))
     58		return;
     59
     60	if (!chip->irq_set_affinity)
     61		return;
     62
     63	assert_raw_spin_locked(&desc->lock);
     64
     65	/*
     66	 * If there was a valid mask to work with, please
     67	 * do the disable, re-program, enable sequence.
     68	 * This is *not* particularly important for level triggered
     69	 * but in a edge trigger case, we might be setting rte
     70	 * when an active trigger is coming in. This could
     71	 * cause some ioapics to mal-function.
     72	 * Being paranoid i guess!
     73	 *
     74	 * For correct operation this depends on the caller
     75	 * masking the irqs.
     76	 */
     77	if (cpumask_any_and(desc->pending_mask, cpu_online_mask) < nr_cpu_ids) {
     78		int ret;
     79
     80		ret = irq_do_set_affinity(data, desc->pending_mask, false);
     81		/*
     82		 * If the there is a cleanup pending in the underlying
     83		 * vector management, reschedule the move for the next
     84		 * interrupt. Leave desc->pending_mask intact.
     85		 */
     86		if (ret == -EBUSY) {
     87			irqd_set_move_pending(data);
     88			return;
     89		}
     90	}
     91	cpumask_clear(desc->pending_mask);
     92}
     93
     94void __irq_move_irq(struct irq_data *idata)
     95{
     96	bool masked;
     97
     98	/*
     99	 * Get top level irq_data when CONFIG_IRQ_DOMAIN_HIERARCHY is enabled,
    100	 * and it should be optimized away when CONFIG_IRQ_DOMAIN_HIERARCHY is
    101	 * disabled. So we avoid an "#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY" here.
    102	 */
    103	idata = irq_desc_get_irq_data(irq_data_to_desc(idata));
    104
    105	if (unlikely(irqd_irq_disabled(idata)))
    106		return;
    107
    108	/*
    109	 * Be careful vs. already masked interrupts. If this is a
    110	 * threaded interrupt with ONESHOT set, we can end up with an
    111	 * interrupt storm.
    112	 */
    113	masked = irqd_irq_masked(idata);
    114	if (!masked)
    115		idata->chip->irq_mask(idata);
    116	irq_move_masked_irq(idata);
    117	if (!masked)
    118		idata->chip->irq_unmask(idata);
    119}