target/linux/d1/patches-6.1/0011-genirq-Add-support-for-oneshot-safe-threaded-EOIs.patch

   1 From ee6459d60f24d91052f0288155f44e6a7f991050 Mon Sep 17 00:00:00 2001
   2 From: Samuel Holland <samuel@sholland.org>
   3 Date: Sat, 7 May 2022 18:34:25 -0500
   4 Subject: [PATCH 011/117] genirq: Add support for oneshot-safe threaded EOIs
   5
   6 irqchips can use the combination of flags IRQCHIP_ONESHOT_SAFE |
   7 IRQCHIP_EOI_THREADED to elide mask operations.
   8
   9 Signed-off-by: Samuel Holland <samuel@sholland.org>
  10 ---
  11  kernel/irq/chip.c      | 36 +++++++++++++++++-------------------
  12  kernel/irq/internals.h |  2 +-
  13  kernel/irq/manage.c    | 12 ++++++------
  14  3 files changed, 24 insertions(+), 26 deletions(-)
  15
  16 --- a/kernel/irq/chip.c
  17 +++ b/kernel/irq/chip.c
  18 @@ -439,16 +439,6 @@ void unmask_irq(struct irq_desc *desc)
  19         }
  20  }
  21
  22 -void unmask_threaded_irq(struct irq_desc *desc)
  23 -{
  24 -       struct irq_chip *chip = desc->irq_data.chip;
  25 -
  26 -       if (chip->flags & IRQCHIP_EOI_THREADED)
  27 -               chip->irq_eoi(&desc->irq_data);
  28 -
  29 -       unmask_irq(desc);
  30 -}
  31 -
  32  /*
  33   *     handle_nested_irq - Handle a nested irq from a irq thread
  34   *     @irq:   the interrupt number
  35 @@ -656,25 +646,33 @@ out_unlock:
  36  }
  37  EXPORT_SYMBOL_GPL(handle_level_irq);
  38
  39 -static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
  40 +void unmask_eoi_threaded_irq(struct irq_desc *desc)
  41  {
  42 -       if (!(desc->istate & IRQS_ONESHOT)) {
  43 +       struct irq_chip *chip = desc->irq_data.chip;
  44 +
  45 +       if (desc->istate & IRQS_ONESHOT)
  46 +               unmask_irq(desc);
  47 +
  48 +       if (chip->flags & IRQCHIP_EOI_THREADED)
  49                 chip->irq_eoi(&desc->irq_data);
  50 +}
  51 +
  52 +static void cond_unmask_eoi_irq(struct irq_desc *desc, struct irq_chip *chip)
  53 +{
  54 +       /* Do not send EOI if the thread will do it for us. */
  55 +       if ((chip->flags & IRQCHIP_EOI_THREADED) && desc->threads_oneshot)
  56                 return;
  57 -       }
  58 +
  59         /*
  60          * We need to unmask in the following cases:
  61          * - Oneshot irq which did not wake the thread (caused by a
  62          *   spurious interrupt or a primary handler handling it
  63          *   completely).
  64          */
  65 -       if (!irqd_irq_disabled(&desc->irq_data) &&
  66 -           irqd_irq_masked(&desc->irq_data) && !desc->threads_oneshot) {
  67 -               chip->irq_eoi(&desc->irq_data);
  68 +       if ((desc->istate & IRQS_ONESHOT) && !desc->threads_oneshot)
  69                 unmask_irq(desc);
  70 -       } else if (!(chip->flags & IRQCHIP_EOI_THREADED)) {
  71 -               chip->irq_eoi(&desc->irq_data);
  72 -       }
  73 +
  74 +       chip->irq_eoi(&desc->irq_data);
  75  }
  76
  77  /**
  78 --- a/kernel/irq/internals.h
  79 +++ b/kernel/irq/internals.h
  80 @@ -93,7 +93,7 @@ extern void irq_percpu_enable(struct irq
  81  extern void irq_percpu_disable(struct irq_desc *desc, unsigned int cpu);
  82  extern void mask_irq(struct irq_desc *desc);
  83  extern void unmask_irq(struct irq_desc *desc);
  84 -extern void unmask_threaded_irq(struct irq_desc *desc);
  85 +extern void unmask_eoi_threaded_irq(struct irq_desc *desc);
  86
  87  #ifdef CONFIG_SPARSE_IRQ
  88  static inline void irq_mark_irq(unsigned int irq) { }
  89 --- a/kernel/irq/manage.c
  90 +++ b/kernel/irq/manage.c
  91 @@ -1074,9 +1074,9 @@ static int irq_wait_for_interrupt(struct
  92  static void irq_finalize_oneshot(struct irq_desc *desc,
  93                                  struct irqaction *action)
  94  {
  95 -       if (!(desc->istate & IRQS_ONESHOT) ||
  96 -           action->handler == irq_forced_secondary_handler)
  97 +       if (action->handler == irq_forced_secondary_handler)
  98                 return;
  99 +
 100  again:
 101         chip_bus_lock(desc);
 102         raw_spin_lock_irq(&desc->lock);
 103 @@ -1112,9 +1112,8 @@ again:
 104
 105         desc->threads_oneshot &= ~action->thread_mask;
 106
 107 -       if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) &&
 108 -           irqd_irq_masked(&desc->irq_data))
 109 -               unmask_threaded_irq(desc);
 110 +       if (!desc->threads_oneshot)
 111 +               unmask_eoi_threaded_irq(desc);
 112
 113  out_unlock:
 114         raw_spin_unlock_irq(&desc->lock);
 115 @@ -1662,7 +1661,8 @@ __setup_irq(unsigned int irq, struct irq
 116          * !ONESHOT irqs the thread mask is 0 so we can avoid a
 117          * conditional in irq_wake_thread().
 118          */
 119 -       if (new->flags & IRQF_ONESHOT) {
 120 +       if ((new->flags & IRQF_ONESHOT) ||
 121 +           (desc->irq_data.chip->flags & (IRQCHIP_ONESHOT_SAFE | IRQCHIP_EOI_THREADED)) == (IRQCHIP_ONESHOT_SAFE | IRQCHIP_EOI_THREADED)) {
 122                 /*
 123                  * Unlikely to have 32 resp 64 irqs sharing one line,
 124                  * but who knows.