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 int disable_irq_post = 1;
  26
  27 static int disable_irq_remap;
  28 static struct irq_remap_ops *remap_ops;
  29
  30 static void irq_remapping_disable_io_apic(void)
  31 {
  32         /*
  33          * With interrupt-remapping, for now we will use virtual wire A
  34          * mode, as virtual wire B is little complex (need to configure
  35          * both IOAPIC RTE as well as interrupt-remapping table entry).
  36          * As this gets called during crash dump, keep this simple for
  37          * now.
  38          */
  39         if (cpu_has_apic || apic_from_smp_config())
  40                 disconnect_bsp_APIC(0);
  41 }
  42
  43 static void __init irq_remapping_modify_x86_ops(void)
  44 {
  45         x86_io_apic_ops.disable         = irq_remapping_disable_io_apic;
  46 }
  47
  48 static __init int setup_nointremap(char *str)
  49 {
  50         disable_irq_remap = 1;
  51         return 0;
  52 }
  53 early_param("nointremap", setup_nointremap);
  54
  55 static __init int setup_irqremap(char *str)
  56 {
  57         if (!str)
  58                 return -EINVAL;
  59
  60         while (*str) {
  61                 if (!strncmp(str, "on", 2))
  62                         disable_irq_remap = 0;
  63                 else if (!strncmp(str, "off", 3))
  64                         disable_irq_remap = 1;
  65                 else if (!strncmp(str, "nosid", 5))
  66                         disable_sourceid_checking = 1;
  67                 else if (!strncmp(str, "no_x2apic_optout", 16))
  68                         no_x2apic_optout = 1;
  69
  70                 str += strcspn(str, ",");
  71                 while (*str == ',')
  72                         str++;
  73         }
  74
  75         return 0;
  76 }
  77 early_param("intremap", setup_irqremap);
  78
  79 void set_irq_remapping_broken(void)
  80 {
  81         irq_remap_broken = 1;
  82 }
  83
  84 bool irq_remapping_cap(enum irq_remap_cap cap)
  85 {
  86         if (!remap_ops || disable_irq_post)
  87                 return 0;
  88
  89         return (remap_ops->capability & (1 << cap));
  90 }
  91 EXPORT_SYMBOL_GPL(irq_remapping_cap);
  92
  93 int __init irq_remapping_prepare(void)
  94 {
  95         if (disable_irq_remap)
  96                 return -ENOSYS;
  97
  98         if (intel_irq_remap_ops.prepare() == 0)
  99                 remap_ops = &intel_irq_remap_ops;
 100         else if (IS_ENABLED(CONFIG_AMD_IOMMU) &&
 101                  amd_iommu_irq_ops.prepare() == 0)
 102                 remap_ops = &amd_iommu_irq_ops;
 103         else
 104                 return -ENOSYS;
 105
 106         return 0;
 107 }
 108
 109 int __init irq_remapping_enable(void)
 110 {
 111         int ret;
 112
 113         if (!remap_ops->enable)
 114                 return -ENODEV;
 115
 116         ret = remap_ops->enable();
 117
 118         if (irq_remapping_enabled)
 119                 irq_remapping_modify_x86_ops();
 120
 121         return ret;
 122 }
 123
 124 void irq_remapping_disable(void)
 125 {
 126         if (irq_remapping_enabled && remap_ops->disable)
 127                 remap_ops->disable();
 128 }
 129
 130 int irq_remapping_reenable(int mode)
 131 {
 132         if (irq_remapping_enabled && remap_ops->reenable)
 133                 return remap_ops->reenable(mode);
 134
 135         return 0;
 136 }
 137
 138 int __init irq_remap_enable_fault_handling(void)
 139 {
 140         if (!irq_remapping_enabled)
 141                 return 0;
 142
 143         if (!remap_ops->enable_faulting)
 144                 return -ENODEV;
 145
 146         return remap_ops->enable_faulting();
 147 }
 148
 149 void panic_if_irq_remap(const char *msg)
 150 {
 151         if (irq_remapping_enabled)
 152                 panic(msg);
 153 }
 154
 155 void ir_ack_apic_edge(struct irq_data *data)
 156 {
 157         ack_APIC_irq();
 158 }
 159
 160 /**
 161  * irq_remapping_get_ir_irq_domain - Get the irqdomain associated with the IOMMU
 162  *                                   device serving request @info
 163  * @info: interrupt allocation information, used to identify the IOMMU device
 164  *
 165  * It's used to get parent irqdomain for HPET and IOAPIC irqdomains.
 166  * Returns pointer to IRQ domain, or NULL on failure.
 167  */
 168 struct irq_domain *
 169 irq_remapping_get_ir_irq_domain(struct irq_alloc_info *info)
 170 {
 171         if (!remap_ops || !remap_ops->get_ir_irq_domain)
 172                 return NULL;
 173
 174         return remap_ops->get_ir_irq_domain(info);
 175 }
 176
 177 /**
 178  * irq_remapping_get_irq_domain - Get the irqdomain serving the request @info
 179  * @info: interrupt allocation information, used to identify the IOMMU device
 180  *
 181  * There will be one PCI MSI/MSIX irqdomain associated with each interrupt
 182  * remapping device, so this interface is used to retrieve the PCI MSI/MSIX
 183  * irqdomain serving request @info.
 184  * Returns pointer to IRQ domain, or NULL on failure.
 185  */
 186 struct irq_domain *
 187 irq_remapping_get_irq_domain(struct irq_alloc_info *info)
 188 {
 189         if (!remap_ops || !remap_ops->get_irq_domain)
 190                 return NULL;
 191
 192         return remap_ops->get_irq_domain(info);
 193 }