drivers/iommu/irq_remapping.c

   1 #include <linux/seq_file.h>
   2 #include <linux/cpumask.h>
   3 #include <linux/kernel.h>
   4 #include <linux/string.h>
   5 #include <linux/errno.h>
   6 #include <linux/msi.h>
   7 #include <linux/irq.h>
   8 #include <linux/pci.h>
   9 #include <linux/irqdomain.h>
  10
  11 #include <asm/hw_irq.h>
  12 #include <asm/irq_remapping.h>
  13 #include <asm/processor.h>
  14 #include <asm/x86_init.h>
  15 #include <asm/apic.h>
  16 #include <asm/hpet.h>
  17
  18 #include "irq_remapping.h"
  19
  20 int irq_remapping_enabled;
  21 int irq_remap_broken;
  22 int disable_sourceid_checking;
  23 int no_x2apic_optout;
  24
  25 static int disable_irq_remap;
  26 static struct irq_remap_ops *remap_ops;
  27
  28 static void irq_remapping_disable_io_apic(void)
  29 {
  30         /*
  31          * With interrupt-remapping, for now we will use virtual wire A
  32          * mode, as virtual wire B is little complex (need to configure
  33          * both IOAPIC RTE as well as interrupt-remapping table entry).
  34          * As this gets called during crash dump, keep this simple for
  35          * now.
  36          */
  37         if (cpu_has_apic || apic_from_smp_config())
  38                 disconnect_bsp_APIC(0);
  39 }
  40
  41 static void __init irq_remapping_modify_x86_ops(void)
  42 {
  43         x86_io_apic_ops.disable         = irq_remapping_disable_io_apic;
  44 }
  45
  46 static __init int setup_nointremap(char *str)
  47 {
  48         disable_irq_remap = 1;
  49         return 0;
  50 }
  51 early_param("nointremap", setup_nointremap);
  52
  53 static __init int setup_irqremap(char *str)
  54 {
  55         if (!str)
  56                 return -EINVAL;
  57
  58         while (*str) {
  59                 if (!strncmp(str, "on", 2))
  60                         disable_irq_remap = 0;
  61                 else if (!strncmp(str, "off", 3))
  62                         disable_irq_remap = 1;
  63                 else if (!strncmp(str, "nosid", 5))
  64                         disable_sourceid_checking = 1;
  65                 else if (!strncmp(str, "no_x2apic_optout", 16))
  66                         no_x2apic_optout = 1;
  67
  68                 str += strcspn(str, ",");
  69                 while (*str == ',')
  70                         str++;
  71         }
  72
  73         return 0;
  74 }
  75 early_param("intremap", setup_irqremap);
  76
  77 void set_irq_remapping_broken(void)
  78 {
  79         irq_remap_broken = 1;
  80 }
  81
  82 int __init irq_remapping_prepare(void)
  83 {
  84         if (disable_irq_remap)
  85                 return -ENOSYS;
  86
  87         if (intel_irq_remap_ops.prepare() == 0)
  88                 remap_ops = &intel_irq_remap_ops;
  89         else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
  90                  amd_iommu_irq_ops.prepare() == 0)
  91                 remap_ops = &amd_iommu_irq_ops;
  92         else
  93                 return -ENOSYS;
  94
  95         return 0;
  96 }
  97
  98 int __init irq_remapping_enable(void)
  99 {
 100         int ret;
 101
 102         if (!remap_ops->enable)
 103                 return -ENODEV;
 104
 105         ret = remap_ops->enable();
 106
 107         if (irq_remapping_enabled)
 108                 irq_remapping_modify_x86_ops();
 109
 110         return ret;
 111 }
 112
 113 void irq_remapping_disable(void)
 114 {
 115         if (irq_remapping_enabled && remap_ops->disable)
 116                 remap_ops->disable();
 117 }
 118
 119 int irq_remapping_reenable(int mode)
 120 {
 121         if (irq_remapping_enabled && remap_ops->reenable)
 122                 return remap_ops->reenable(mode);
 123
 124         return 0;
 125 }
 126
 127 int __init irq_remap_enable_fault_handling(void)
 128 {
 129         if (!irq_remapping_enabled)
 130                 return 0;
 131
 132         if (!remap_ops->enable_faulting)
 133                 return -ENODEV;
 134
 135         return remap_ops->enable_faulting();
 136 }
 137
 138 void panic_if_irq_remap(const char *msg)
 139 {
 140         if (irq_remapping_enabled)
 141                 panic(msg);
 142 }
 143
 144 void ir_ack_apic_edge(struct irq_data *data)
 145 {
 146         ack_APIC_irq();
 147 }
 148
 149 /**
 150  * irq_remapping_get_ir_irq_domain - Get the irqdomain associated with the IOMMU
 151  *                                   device serving request @info
 152  * @info: interrupt allocation information, used to identify the IOMMU device
 153  *
 154  * It's used to get parent irqdomain for HPET and IOAPIC irqdomains.
 155  * Returns pointer to IRQ domain, or NULL on failure.
 156  */
 157 struct irq_domain *
 158 irq_remapping_get_ir_irq_domain(struct irq_alloc_info *info)
 159 {
 160         if (!remap_ops || !remap_ops->get_ir_irq_domain)
 161                 return NULL;
 162
 163         return remap_ops->get_ir_irq_domain(info);
 164 }
 165
 166 /**
 167  * irq_remapping_get_irq_domain - Get the irqdomain serving the request @info
 168  * @info: interrupt allocation information, used to identify the IOMMU device
 169  *
 170  * There will be one PCI MSI/MSIX irqdomain associated with each interrupt
 171  * remapping device, so this interface is used to retrieve the PCI MSI/MSIX
 172  * irqdomain serving request @info.
 173  * Returns pointer to IRQ domain, or NULL on failure.
 174  */
 175 struct irq_domain *
 176 irq_remapping_get_irq_domain(struct irq_alloc_info *info)
 177 {
 178         if (!remap_ops || !remap_ops->get_irq_domain)
 179                 return NULL;
 180
 181         return remap_ops->get_irq_domain(info);
 182 }