x86/{acpi,ioapic}: handle interrupt source overrides

6 files changed, 203 insertions, 14 deletions

diff --git a/arch/x86/machine/acpi.c b/arch/x86/machine/acpi.c
index 1f7e5683..6d5e06e6 100644
--- a/arch/x86/machine/acpi.c
+++ b/arch/x86/machine/acpi.c
@@ -16,6 +16,7 @@
  */
 
 #include <assert.h>
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ -80,6 +81,7 @@ struct acpi_rsdt {
  */
 #define ACPI_MADT_ENTRY_LAPIC     0
 #define ACPI_MADT_ENTRY_IOAPIC    1
+#define ACPI_MADT_ENTRY_ISO       2
 
 struct acpi_madt_entry_hdr {
     uint8_t type;
@@ -103,11 +105,29 @@ struct acpi_madt_entry_ioapic {
     uint32_t base;
 } __packed;
 
+#define ACPI_MADT_ISO_POL_DEFAULT   0x00
+#define ACPI_MADT_ISO_POL_HIGH      0x01
+#define ACPI_MADT_ISO_POL_LOW       0x03
+#define ACPI_MADT_ISO_POL_MASK      0x03
+#define ACPI_MADT_ISO_TRIG_DEFAULT  0x00
+#define ACPI_MADT_ISO_TRIG_EDGE     0x04
+#define ACPI_MADT_ISO_TRIG_LEVEL    0x0c
+#define ACPI_MADT_ISO_TRIG_MASK     0x0c
+
+struct acpi_madt_entry_iso {
+    struct acpi_madt_entry_hdr header;
+    uint8_t bus;
+    uint8_t source;
+    uint32_t gsi;
+    int16_t flags;
+} __packed;
+
 union acpi_madt_entry {
     uint8_t type;
     struct acpi_madt_entry_hdr header;
     struct acpi_madt_entry_lapic lapic;
     struct acpi_madt_entry_ioapic ioapic;
+    struct acpi_madt_entry_iso iso;
 } __packed;
 
 #define ACPI_MADT_PC_COMPAT 0x1
@@ -487,6 +507,45 @@ acpi_load_ioapic(const struct acpi_madt_entry_ioapic *ioapic)
 }
 
 static void __init
+acpi_load_iso(const struct acpi_madt_entry_iso *iso)
+{
+    bool active_high, edge_triggered;
+
+    if (iso->bus != 0) {
+        printf("acpi: error: invalid interrupt source override bus\n");
+        return;
+    }
+
+    switch (iso->flags & ACPI_MADT_ISO_POL_MASK) {
+    case ACPI_MADT_ISO_POL_DEFAULT:
+    case ACPI_MADT_ISO_POL_HIGH:
+        active_high = true;
+        break;
+    case ACPI_MADT_ISO_POL_LOW:
+        active_high = false;
+        break;
+    default:
+        printf("acpi: error: invalid polarity\n");
+        return;
+    }
+
+    switch (iso->flags & ACPI_MADT_ISO_TRIG_MASK) {
+    case ACPI_MADT_ISO_TRIG_DEFAULT:
+    case ACPI_MADT_ISO_TRIG_EDGE:
+        edge_triggered = true;
+        break;
+    case ACPI_MADT_ISO_TRIG_LEVEL:
+        edge_triggered = false;
+        break;
+    default:
+        printf("acpi: error: invalid trigger mode\n");
+        return;
+    }
+
+    ioapic_override(iso->source, iso->gsi, active_high, edge_triggered);
+}
+
+static void __init
 acpi_load_madt(void)
 {
     const struct acpi_sdth *table;
@@ -501,10 +560,6 @@ acpi_load_madt(void)
     lapic_setup(madt->lapic_addr);
     is_bsp = 1;
 
-    /*
-     * TODO Handle interrupt overrides
-     */
-
     acpi_madt_foreach(madt, &iter) {
         switch (iter.entry->type) {
         case ACPI_MADT_ENTRY_LAPIC:
@@ -512,6 +567,10 @@ acpi_load_madt(void)
             break;
         case ACPI_MADT_ENTRY_IOAPIC:
             acpi_load_ioapic(&iter.entry->ioapic);
+            break;
+        case ACPI_MADT_ENTRY_ISO:
+            acpi_load_iso(&iter.entry->iso);
+            break;
         }
     }
 
diff --git a/arch/x86/machine/ioapic.c b/arch/x86/machine/ioapic.c
index d48cc307..e49cb309 100644
--- a/arch/x86/machine/ioapic.c
+++ b/arch/x86/machine/ioapic.c
@@ -29,6 +29,7 @@
 #include <machine/cpu.h>
 #include <machine/ioapic.h>
 #include <machine/lapic.h>
+#include <machine/pic.h>
 #include <machine/trap.h>
 #include <vm/vm_kmem.h>
 
@@ -40,6 +41,10 @@
 #define IOAPIC_VERSION_MAXREDIR_MASK    0x00ff0000
 #define IOAPIC_VERSION_MAXREDIR_SHIFT   16
 
+#define IOAPIC_ENTLOW_FIXED_DEST        0x00000
+#define IOAPIC_ENTLOW_PHYS_DELIVERY     0x00000
+#define IOAPIC_ENTLOW_ACTIVE_LOW        0x02000
+#define IOAPIC_ENTLOW_LEVEL             0x08000
 #define IOAPIC_ENTLOW_INTRMASK          0x10000
 
 #define IOAPIC_MAX_ENTRIES 24
@@ -55,6 +60,16 @@ struct ioapic_map {
     uint32_t win;
 };
 
+/*
+ * Interrupt source override descriptor.
+ */
+struct ioapic_iso {
+    uint8_t source;
+    uint32_t gsi;
+    bool active_high;
+    bool edge_triggered;
+};
+
 struct ioapic {
     struct spinlock lock;
     unsigned int id;
@@ -67,6 +82,51 @@ struct ioapic {
 
 static unsigned int ioapic_nr_devs;
 
+static struct ioapic_iso ioapic_isos[PIC_MAX_INTR + 1];
+static unsigned int ioapic_nr_isos;
+
+static void
+ioapic_iso_init(struct ioapic_iso *iso, uint8_t source, uint32_t gsi,
+                bool active_high, bool edge_triggered)
+{
+    iso->source = source;
+    iso->gsi = gsi;
+    iso->active_high = active_high;
+    iso->edge_triggered = edge_triggered;
+}
+
+static struct ioapic_iso * __init
+ioapic_alloc_iso(void)
+{
+    struct ioapic_iso *iso;
+
+    if (ioapic_nr_isos >= ARRAY_SIZE(ioapic_isos)) {
+        printf("ioapic: error: too many interrupt overrides\n");
+        return NULL;
+    }
+
+    iso = &ioapic_isos[ioapic_nr_isos];
+    ioapic_nr_isos++;
+    return iso;
+}
+
+static struct ioapic_iso *
+ioapic_lookup_iso(unsigned int intr)
+{
+    struct ioapic_iso *iso;
+    unsigned int i;
+
+    for (i = 0; i < ioapic_nr_isos; i++) {
+        iso = &ioapic_isos[i];
+
+        if (intr == iso->source) {
+            return iso;
+        }
+    }
+
+    return NULL;
+}
+
 static uint32_t
 ioapic_read(struct ioapic *ioapic, uint8_t reg)
 {
@@ -161,18 +221,52 @@ ioapic_compute_id(const struct ioapic *ioapic, unsigned int intr)
 }
 
 static void
+ioapic_compute_entry(uint32_t *highp, uint32_t *lowp,
+                     unsigned int apic_id, unsigned int intr,
+                     bool active_high, bool edge_triggered)
+{
+    assert(apic_id < 16);
+    assert(intr < (TRAP_NR_VECTORS - TRAP_INTR_FIRST));
+
+    *highp = apic_id << 24;
+    *lowp = (!edge_triggered ? IOAPIC_ENTLOW_LEVEL : 0)
+            | (!active_high ? IOAPIC_ENTLOW_ACTIVE_LOW : 0)
+            | IOAPIC_ENTLOW_PHYS_DELIVERY
+            | IOAPIC_ENTLOW_FIXED_DEST
+            | (TRAP_INTR_FIRST + intr);
+}
+
+static void
 ioapic_enable(void *priv, unsigned int intr, unsigned int cpu)
 {
+    bool active_high, edge_triggered;
+    const struct ioapic_iso *iso;
+    uint32_t high, low, gsi;
     struct ioapic *ioapic;
     unsigned long flags;
     unsigned int id;
 
+    iso = ioapic_lookup_iso(intr);
+
+    /* XXX These are defaults that should work with architectural devices */
+    if (iso == NULL) {
+        active_high = true;
+        edge_triggered = true;
+        gsi = intr;
+    } else {
+        active_high = iso->active_high;
+        edge_triggered = iso->edge_triggered;
+        gsi = iso->gsi;
+    }
+
     ioapic = priv;
-    id = ioapic_compute_id(ioapic, intr);
+    id = ioapic_compute_id(ioapic, gsi);
+    ioapic_compute_entry(&high, &low, cpu_apic_id(cpu), intr,
+                         active_high, edge_triggered);
 
     spinlock_lock_intr_save(&ioapic->lock, &flags);
-    ioapic_write_entry_high(ioapic, id, cpu_apic_id(cpu) << 24);
-    ioapic_write_entry_low(ioapic, id, TRAP_INTR_FIRST + intr);
+    ioapic_write_entry_high(ioapic, id, high);
+    ioapic_write_entry_low(ioapic, id, low);
     spinlock_unlock_intr_restore(&ioapic->lock, flags);
 }
 
@@ -207,6 +301,13 @@ static const struct intr_ops ioapic_ops = {
 };
 
 void __init
+ioapic_setup(void)
+{
+    ioapic_nr_devs = 0;
+    ioapic_nr_isos = 0;
+}
+
+void __init
 ioapic_register(unsigned int apic_id, uintptr_t addr, unsigned int intr_base)
 {
     struct ioapic *ioapic;
@@ -216,3 +317,17 @@ ioapic_register(unsigned int apic_id, uintptr_t addr, unsigned int intr_base)
                       ioapic->first_intr, ioapic->last_intr);
 }
 
+void __init
+ioapic_override(uint8_t source, uint32_t gsi,
+                bool active_high, bool edge_triggered)
+{
+    struct ioapic_iso *iso;
+
+    iso = ioapic_alloc_iso();
+
+    if (iso == NULL) {
+        return;
+    }
+
+    ioapic_iso_init(iso, source, gsi, active_high, edge_triggered);
+}
diff --git a/arch/x86/machine/ioapic.h b/arch/x86/machine/ioapic.h
index d508904e..b9a702d3 100644
--- a/arch/x86/machine/ioapic.h
+++ b/arch/x86/machine/ioapic.h
@@ -18,12 +18,24 @@
 #ifndef _KERN_IOAPIC_H
 #define _KERN_IOAPIC_H
 
+#include <stdbool.h>
 #include <stdint.h>
 
 /*
+ * Initialize the ioapic module.
+ */
+void ioapic_setup(void);
+
+/*
  * Register an I/O APIC controller.
  */
 void ioapic_register(unsigned int apic_id, uintptr_t addr,
                      unsigned int gsi_base);
 
+/*
+ * Report an interrupt source override.
+ */
+void ioapic_override(uint8_t source, uint32_t gsi,
+                     bool active_high, bool edge_triggered);
+
 #endif /* _KERN_IOAPIC_H */
diff --git a/arch/x86/machine/pic.c b/arch/x86/machine/pic.c
index ab30ac20..8ef57538 100644
--- a/arch/x86/machine/pic.c
+++ b/arch/x86/machine/pic.c
@@ -51,8 +51,6 @@
  */
 #define PIC_SLAVE_INTR      2
 #define PIC_SPURIOUS_INTR   7
-#define PIC_NR_INTRS        8
-#define PIC_MAX_INTR        ((PIC_NR_INTRS * 2) - 1)
 
 static unsigned int pic_nr_slave_intrs;
 
diff --git a/arch/x86/machine/pic.h b/arch/x86/machine/pic.h
index e49d336e..89833d00 100644
--- a/arch/x86/machine/pic.h
+++ b/arch/x86/machine/pic.h
@@ -18,7 +18,15 @@
 #ifndef _X86_PIC_H
 #define _X86_PIC_H
 
-#include <machine/trap.h>
+/*
+ * Interrupts per PIC.
+ */
+#define PIC_NR_INTRS    8
+
+/*
+ * Maximum global interrupt number.
+ */
+#define PIC_MAX_INTR    ((PIC_NR_INTRS * 2) - 1)
 
 /*
  * Initialize the pic module.
diff --git a/arch/x86/machine/trap.h b/arch/x86/machine/trap.h
index 7bda9cf3..e4d5912b 100644
--- a/arch/x86/machine/trap.h
+++ b/arch/x86/machine/trap.h
@@ -61,10 +61,7 @@
 #define TRAP_LAPIC_ERROR        254
 #define TRAP_LAPIC_SPURIOUS     255
 
-/*
- * Vector identifying an unhandled trap.
- */
-#define TRAP_DEFAULT        256
+#define TRAP_NR_VECTORS         256
 
 #ifndef __ASSEMBLER__