drivers/irqchip/irq-gic-common.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2002 ARM Limited, All Rights Reserved.
   4  */
   5
   6 #include <linux/interrupt.h>
   7 #include <linux/io.h>
   8 #include <linux/irq.h>
   9 #include <linux/irqchip/arm-gic.h>
  10
  11 #include "irq-gic-common.h"
  12
  13 static DEFINE_RAW_SPINLOCK(irq_controller_lock);
  14
  15 static const struct gic_kvm_info *gic_kvm_info;
  16
  17 const struct gic_kvm_info *gic_get_kvm_info(void)
  18 {
  19         return gic_kvm_info;
  20 }
  21
  22 void gic_set_kvm_info(const struct gic_kvm_info *info)
  23 {
  24         BUG_ON(gic_kvm_info != NULL);
  25         gic_kvm_info = info;
  26 }
  27
  28 void gic_enable_of_quirks(const struct device_node *np,
  29                           const struct gic_quirk *quirks, void *data)
  30 {
  31         for (; quirks->desc; quirks++) {
  32                 if (!of_device_is_compatible(np, quirks->compatible))
  33                         continue;
  34                 if (quirks->init(data))
  35                         pr_info("GIC: enabling workaround for %s\n",
  36                                 quirks->desc);
  37         }
  38 }
  39
  40 void gic_enable_quirks(u32 iidr, const struct gic_quirk *quirks,
  41                 void *data)
  42 {
  43         for (; quirks->desc; quirks++) {
  44                 if (quirks->iidr != (quirks->mask & iidr))
  45                         continue;
  46                 if (quirks->init(data))
  47                         pr_info("GIC: enabling workaround for %s\n",
  48                                 quirks->desc);
  49         }
  50 }
  51
  52 int gic_configure_irq(unsigned int irq, unsigned int type,
  53                        void __iomem *base, void (*sync_access)(void))
  54 {
  55         u32 confmask = 0x2 << ((irq % 16) * 2);
  56         u32 confoff = (irq / 16) * 4;
  57         u32 val, oldval;
  58         int ret = 0;
  59         unsigned long flags;
  60
  61         /*
  62          * Read current configuration register, and insert the config
  63          * for "irq", depending on "type".
  64          */
  65         raw_spin_lock_irqsave(&irq_controller_lock, flags);
  66         val = oldval = readl_relaxed(base + GIC_DIST_CONFIG + confoff);
  67         if (type & IRQ_TYPE_LEVEL_MASK)
  68                 val &= ~confmask;
  69         else if (type & IRQ_TYPE_EDGE_BOTH)
  70                 val |= confmask;
  71
  72         /* If the current configuration is the same, then we are done */
  73         if (val == oldval) {
  74                 raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
  75                 return 0;
  76         }
  77
  78         /*
  79          * Write back the new configuration, and possibly re-enable
  80          * the interrupt. If we fail to write a new configuration for
  81          * an SPI then WARN and return an error. If we fail to write the
  82          * configuration for a PPI this is most likely because the GIC
  83          * does not allow us to set the configuration or we are in a
  84          * non-secure mode, and hence it may not be catastrophic.
  85          */
  86         writel_relaxed(val, base + GIC_DIST_CONFIG + confoff);
  87         if (readl_relaxed(base + GIC_DIST_CONFIG + confoff) != val) {
  88                 if (WARN_ON(irq >= 32))
  89                         ret = -EINVAL;
  90                 else
  91                         pr_warn("GIC: PPI%d is secure or misconfigured\n",
  92                                 irq - 16);
  93         }
  94         raw_spin_unlock_irqrestore(&irq_controller_lock, flags);
  95
  96         if (sync_access)
  97                 sync_access();
  98
  99         return ret;
 100 }
 101
 102 void gic_dist_config(void __iomem *base, int gic_irqs,
 103                      void (*sync_access)(void))
 104 {
 105         unsigned int i;
 106
 107         /*
 108          * Set all global interrupts to be level triggered, active low.
 109          */
 110         for (i = 32; i < gic_irqs; i += 16)
 111                 writel_relaxed(GICD_INT_ACTLOW_LVLTRIG,
 112                                         base + GIC_DIST_CONFIG + i / 4);
 113
 114         /*
 115          * Set priority on all global interrupts.
 116          */
 117         for (i = 32; i < gic_irqs; i += 4)
 118                 writel_relaxed(GICD_INT_DEF_PRI_X4, base + GIC_DIST_PRI + i);
 119
 120         /*
 121          * Deactivate and disable all SPIs. Leave the PPI and SGIs
 122          * alone as they are in the redistributor registers on GICv3.
 123          */
 124         for (i = 32; i < gic_irqs; i += 32) {
 125                 writel_relaxed(GICD_INT_EN_CLR_X32,
 126                                base + GIC_DIST_ACTIVE_CLEAR + i / 8);
 127                 writel_relaxed(GICD_INT_EN_CLR_X32,
 128                                base + GIC_DIST_ENABLE_CLEAR + i / 8);
 129         }
 130
 131         if (sync_access)
 132                 sync_access();
 133 }
 134
 135 void gic_cpu_config(void __iomem *base, void (*sync_access)(void))
 136 {
 137         int i;
 138
 139         /*
 140          * Deal with the banked PPI and SGI interrupts - disable all
 141          * PPI interrupts, ensure all SGI interrupts are enabled.
 142          * Make sure everything is deactivated.
 143          */
 144         writel_relaxed(GICD_INT_EN_CLR_X32, base + GIC_DIST_ACTIVE_CLEAR);
 145         writel_relaxed(GICD_INT_EN_CLR_PPI, base + GIC_DIST_ENABLE_CLEAR);
 146         writel_relaxed(GICD_INT_EN_SET_SGI, base + GIC_DIST_ENABLE_SET);
 147
 148         /*
 149          * Set priority on PPI and SGI interrupts
 150          */
 151         for (i = 0; i < 32; i += 4)
 152                 writel_relaxed(GICD_INT_DEF_PRI_X4,
 153                                         base + GIC_DIST_PRI + i * 4 / 4);
 154
 155         if (sync_access)
 156                 sync_access();
 157 }