/* * ARM Generic/Distributed Interrupt Controller * * Copyright (c) 2006-2007 CodeSourcery. * Written by Paul Brook * * This code is licenced under the GPL. */ /* This file contains implementation code for the RealView EB interrupt controller, MPCore distributed interrupt controller and ARMv7-M Nested Vectored Interrupt Controller. */ //#define DEBUG_GIC #ifdef DEBUG_GIC #define DPRINTF(fmt, ...) \ do { printf("arm_gic: " fmt , ## __VA_ARGS__); } while (0) #else #define DPRINTF(fmt, ...) do {} while(0) #endif #ifdef NVIC static const uint8_t gic_id[] = { 0x00, 0xb0, 0x1b, 0x00, 0x0d, 0xe0, 0x05, 0xb1 }; /* The NVIC has 16 internal vectors. However these are not exposed through the normal GIC interface. */ #define GIC_BASE_IRQ 32 #else static const uint8_t gic_id[] = { 0x90, 0x13, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 }; #define GIC_BASE_IRQ 0 #endif typedef struct gic_irq_state { /* ??? The documentation seems to imply the enable bits are global, even for per-cpu interrupts. This seems strange. */ unsigned enabled:1; unsigned pending:NCPU; unsigned active:NCPU; unsigned level:NCPU; unsigned model:1; /* 0 = N:N, 1 = 1:N */ unsigned trigger:1; /* nonzero = edge triggered. */ } gic_irq_state; #define ALL_CPU_MASK ((1 << NCPU) - 1) #define GIC_SET_ENABLED(irq) s->irq_state[irq].enabled = 1 #define GIC_CLEAR_ENABLED(irq) s->irq_state[irq].enabled = 0 #define GIC_TEST_ENABLED(irq) s->irq_state[irq].enabled #define GIC_SET_PENDING(irq, cm) s->irq_state[irq].pending |= (cm) #define GIC_CLEAR_PENDING(irq, cm) s->irq_state[irq].pending &= ~(cm) #define GIC_TEST_PENDING(irq, cm) ((s->irq_state[irq].pending & (cm)) != 0) #define GIC_SET_ACTIVE(irq, cm) s->irq_state[irq].active |= (cm) #define GIC_CLEAR_ACTIVE(irq, cm) s->irq_state[irq].active &= ~(cm) #define GIC_TEST_ACTIVE(irq, cm) ((s->irq_state[irq].active & (cm)) != 0) #define GIC_SET_MODEL(irq) s->irq_state[irq].model = 1 #define GIC_CLEAR_MODEL(irq) s->irq_state[irq].model = 0 #define GIC_TEST_MODEL(irq) s->irq_state[irq].model #define GIC_SET_LEVEL(irq, cm) s->irq_state[irq].level = (cm) #define GIC_CLEAR_LEVEL(irq, cm) s->irq_state[irq].level &= ~(cm) #define GIC_TEST_LEVEL(irq, cm) ((s->irq_state[irq].level & (cm)) != 0) #define GIC_SET_TRIGGER(irq) s->irq_state[irq].trigger = 1 #define GIC_CLEAR_TRIGGER(irq) s->irq_state[irq].trigger = 0 #define GIC_TEST_TRIGGER(irq) s->irq_state[irq].trigger #define GIC_GET_PRIORITY(irq, cpu) \ (((irq) < 32) ? s->priority1[irq][cpu] : s->priority2[(irq) - 32]) #ifdef NVIC #define GIC_TARGET(irq) 1 #else #define GIC_TARGET(irq) s->irq_target[irq] #endif typedef struct gic_state { qemu_irq parent_irq[NCPU]; int enabled; int cpu_enabled[NCPU]; gic_irq_state irq_state[GIC_NIRQ]; #ifndef NVIC int irq_target[GIC_NIRQ]; #endif int priority1[32][NCPU]; int priority2[GIC_NIRQ - 32]; int last_active[GIC_NIRQ][NCPU]; int priority_mask[NCPU]; int running_irq[NCPU]; int running_priority[NCPU]; int current_pending[NCPU]; qemu_irq *in; #ifdef NVIC void *nvic; #endif } gic_state; /* TODO: Many places that call this routine could be optimized. */ /* Update interrupt status after enabled or pending bits have been changed. */ static void gic_update(gic_state *s) { int best_irq; int best_prio; int irq; int level; int cpu; int cm; for (cpu = 0; cpu < NCPU; cpu++) { cm = 1 << cpu; s->current_pending[cpu] = 1023; if (!s->enabled || !s->cpu_enabled[cpu]) { qemu_irq_lower(s->parent_irq[cpu]); return; } best_prio = 0x100; best_irq = 1023; for (irq = 0; irq < GIC_NIRQ; irq++) { if (GIC_TEST_ENABLED(irq) && GIC_TEST_PENDING(irq, cm)) { if (GIC_GET_PRIORITY(irq, cpu) < best_prio) { best_prio = GIC_GET_PRIORITY(irq, cpu); best_irq = irq; } } } level = 0; if (best_prio <= s->priority_mask[cpu]) { s->current_pending[cpu] = best_irq; if (best_prio < s->running_priority[cpu]) { DPRINTF("Raised pending IRQ %d\n", best_irq); level = 1; } } qemu_set_irq(s->parent_irq[cpu], level); } } static void __attribute__((unused)) gic_set_pending_private(gic_state *s, int cpu, int irq) { int cm = 1 << cpu; if (GIC_TEST_PENDING(irq, cm)) return; DPRINTF("Set %d pending cpu %d\n", irq, cpu); GIC_SET_PENDING(irq, cm); gic_update(s); } /* Process a change in an external IRQ input. */ static void gic_set_irq(void *opaque, int irq, int level) { gic_state *s = (gic_state *)opaque; /* The first external input line is internal interrupt 32. */ irq += 32; if (level == GIC_TEST_LEVEL(irq, ALL_CPU_MASK)) return; if (level) { GIC_SET_LEVEL(irq, ALL_CPU_MASK); if (GIC_TEST_TRIGGER(irq) || GIC_TEST_ENABLED(irq)) { DPRINTF("Set %d pending mask %x\n", irq, GIC_TARGET(irq)); GIC_SET_PENDING(irq, GIC_TARGET(irq)); } } else { GIC_CLEAR_LEVEL(irq, ALL_CPU_MASK); } gic_update(s); } static void gic_set_running_irq(gic_state *s, int cpu, int irq) { s->running_irq[cpu] = irq; if (irq == 1023) { s->running_priority[cpu] = 0x100; } else { s->running_priority[cpu] = GIC_GET_PRIORITY(irq, cpu); } gic_update(s); } static uint32_t gic_acknowledge_irq(gic_state *s, int cpu) { int new_irq; int cm = 1 << cpu; new_irq = s->current_pending[cpu]; if (new_irq == 1023 || GIC_GET_PRIORITY(new_irq, cpu) >= s->running_priority[cpu]) { DPRINTF("ACK no pending IRQ\n"); return 1023; } s->last_active[new_irq][cpu] = s->running_irq[cpu]; /* Clear pending flags for both level and edge triggered interrupts. Level triggered IRQs will be reasserted once they become inactive. */ GIC_CLEAR_PENDING(new_irq, GIC_TEST_MODEL(new_irq) ? ALL_CPU_MASK : cm); gic_set_running_irq(s, cpu, new_irq); DPRINTF("ACK %d\n", new_irq); return new_irq; } static void gic_complete_irq(gic_state * s, int cpu, int irq) { int update = 0; int cm = 1 << cpu; DPRINTF("EOI %d\n", irq); if (s->running_irq[cpu] == 1023) return; /* No active IRQ. */ if (irq != 1023) { /* Mark level triggered interrupts as pending if they are still raised. */ if (!GIC_TEST_TRIGGER(irq) && GIC_TEST_ENABLED(irq) && GIC_TEST_LEVEL(irq, cm) && (GIC_TARGET(irq) & cm) != 0) { DPRINTF("Set %d pending mask %x\n", irq, cm); GIC_SET_PENDING(irq, cm); update = 1; } } if (irq != s->running_irq[cpu]) { /* Complete an IRQ that is not currently running. */ int tmp = s->running_irq[cpu]; while (s->last_active[tmp][cpu] != 1023) { if (s->last_active[tmp][cpu] == irq) { s->last_active[tmp][cpu] = s->last_active[irq][cpu]; break; } tmp = s->last_active[tmp][cpu]; } if (update) { gic_update(s); } } else { /* Complete the current running IRQ. */ gic_set_running_irq(s, cpu, s->last_active[s->running_irq[cpu]][cpu]); } } static uint32_t gic_dist_readb(void *opaque, target_phys_addr_t offset) { gic_state *s = (gic_state *)opaque; uint32_t res; int irq; int i; int cpu; int cm; int mask; cpu = gic_get_current_cpu(); cm = 1 << cpu; if (offset < 0x100) { #ifndef NVIC if (offset == 0) return s->enabled; if (offset == 4) return ((GIC_NIRQ / 32) - 1) | ((NCPU - 1) << 5); if (offset < 0x08) return 0; #endif goto bad_reg; } else if (offset < 0x200) { /* Interrupt Set/Clear Enable. */ if (offset < 0x180) irq = (offset - 0x100) * 8; else irq = (offset - 0x180) * 8; irq += GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; res = 0; for (i = 0; i < 8; i++) { if (GIC_TEST_ENABLED(irq + i)) { res |= (1 << i); } } } else if (offset < 0x300) { /* Interrupt Set/Clear Pending. */ if (offset < 0x280) irq = (offset - 0x200) * 8; else irq = (offset - 0x280) * 8; irq += GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; res = 0; mask = (irq < 32) ? cm : ALL_CPU_MASK; for (i = 0; i < 8; i++) { if (GIC_TEST_PENDING(irq + i, mask)) { res |= (1 << i); } } } else if (offset < 0x400) { /* Interrupt Active. */ irq = (offset - 0x300) * 8 + GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; res = 0; mask = (irq < 32) ? cm : ALL_CPU_MASK; for (i = 0; i < 8; i++) { if (GIC_TEST_ACTIVE(irq + i, mask)) { res |= (1 << i); } } } else if (offset < 0x800) { /* Interrupt Priority. */ irq = (offset - 0x400) + GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; res = GIC_GET_PRIORITY(irq, cpu); #ifndef NVIC } else if (offset < 0xc00) { /* Interrupt CPU Target. */ irq = (offset - 0x800) + GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; if (irq >= 29 && irq <= 31) { res = cm; } else { res = GIC_TARGET(irq); } } else if (offset < 0xf00) { /* Interrupt Configuration. */ irq = (offset - 0xc00) * 2 + GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; res = 0; for (i = 0; i < 4; i++) { if (GIC_TEST_MODEL(irq + i)) res |= (1 << (i * 2)); if (GIC_TEST_TRIGGER(irq + i)) res |= (2 << (i * 2)); } #endif } else if (offset < 0xfe0) { goto bad_reg; } else /* offset >= 0xfe0 */ { if (offset & 3) { res = 0; } else { res = gic_id[(offset - 0xfe0) >> 2]; } } return res; bad_reg: hw_error("gic_dist_readb: Bad offset %x\n", (int)offset); return 0; } static uint32_t gic_dist_readw(void *opaque, target_phys_addr_t offset) { uint32_t val; val = gic_dist_readb(opaque, offset); val |= gic_dist_readb(opaque, offset + 1) << 8; return val; } static uint32_t gic_dist_readl(void *opaque, target_phys_addr_t offset) { uint32_t val; #ifdef NVIC gic_state *s = (gic_state *)opaque; uint32_t addr; addr = offset; if (addr < 0x100 || addr > 0xd00) return nvic_readl(s->nvic, addr); #endif val = gic_dist_readw(opaque, offset); val |= gic_dist_readw(opaque, offset + 2) << 16; return val; } static void gic_dist_writeb(void *opaque, target_phys_addr_t offset, uint32_t value) { gic_state *s = (gic_state *)opaque; int irq; int i; int cpu; cpu = gic_get_current_cpu(); if (offset < 0x100) { #ifdef NVIC goto bad_reg; #else if (offset == 0) { s->enabled = (value & 1); DPRINTF("Distribution %sabled\n", s->enabled ? "En" : "Dis"); } else if (offset < 4) { /* ignored. */ } else { goto bad_reg; } #endif } else if (offset < 0x180) { /* Interrupt Set Enable. */ irq = (offset - 0x100) * 8 + GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; if (irq < 16) value = 0xff; for (i = 0; i < 8; i++) { if (value & (1 << i)) { int mask = (irq < 32) ? (1 << cpu) : GIC_TARGET(irq); if (!GIC_TEST_ENABLED(irq + i)) DPRINTF("Enabled IRQ %d\n", irq + i); GIC_SET_ENABLED(irq + i); /* If a raised level triggered IRQ enabled then mark is as pending. */ if (GIC_TEST_LEVEL(irq + i, mask) && !GIC_TEST_TRIGGER(irq + i)) { DPRINTF("Set %d pending mask %x\n", irq + i, mask); GIC_SET_PENDING(irq + i, mask); } } } } else if (offset < 0x200) { /* Interrupt Clear Enable. */ irq = (offset - 0x180) * 8 + GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; if (irq < 16) value = 0; for (i = 0; i < 8; i++) { if (value & (1 << i)) { if (GIC_TEST_ENABLED(irq + i)) DPRINTF("Disabled IRQ %d\n", irq + i); GIC_CLEAR_ENABLED(irq + i); } } } else if (offset < 0x280) { /* Interrupt Set Pending. */ irq = (offset - 0x200) * 8 + GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; if (irq < 16) irq = 0; for (i = 0; i < 8; i++) { if (value & (1 << i)) { GIC_SET_PENDING(irq + i, GIC_TARGET(irq)); } } } else if (offset < 0x300) { /* Interrupt Clear Pending. */ irq = (offset - 0x280) * 8 + GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; for (i = 0; i < 8; i++) { /* ??? This currently clears the pending bit for all CPUs, even for per-CPU interrupts. It's unclear whether this is the corect behavior. */ if (value & (1 << i)) { GIC_CLEAR_PENDING(irq + i, ALL_CPU_MASK); } } } else if (offset < 0x400) { /* Interrupt Active. */ goto bad_reg; } else if (offset < 0x800) { /* Interrupt Priority. */ irq = (offset - 0x400) + GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; if (irq < 32) { s->priority1[irq][cpu] = value; } else { s->priority2[irq - 32] = value; } #ifndef NVIC } else if (offset < 0xc00) { /* Interrupt CPU Target. */ irq = (offset - 0x800) + GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; if (irq < 29) value = 0; else if (irq < 32) value = ALL_CPU_MASK; s->irq_target[irq] = value & ALL_CPU_MASK; } else if (offset < 0xf00) { /* Interrupt Configuration. */ irq = (offset - 0xc00) * 4 + GIC_BASE_IRQ; if (irq >= GIC_NIRQ) goto bad_reg; if (irq < 32) value |= 0xaa; for (i = 0; i < 4; i++) { if (value & (1 << (i * 2))) { GIC_SET_MODEL(irq + i); } else { GIC_CLEAR_MODEL(irq + i); } if (value & (2 << (i * 2))) { GIC_SET_TRIGGER(irq + i); } else { GIC_CLEAR_TRIGGER(irq + i); } } #endif } else { /* 0xf00 is only handled for 32-bit writes. */ goto bad_reg; } gic_update(s); return; bad_reg: hw_error("gic_dist_writeb: Bad offset %x\n", (int)offset); } static void gic_dist_writew(void *opaque, target_phys_addr_t offset, uint32_t value) { gic_dist_writeb(opaque, offset, value & 0xff); gic_dist_writeb(opaque, offset + 1, value >> 8); } static void gic_dist_writel(void *opaque, target_phys_addr_t offset, uint32_t value) { gic_state *s = (gic_state *)opaque; #ifdef NVIC uint32_t addr; addr = offset; if (addr < 0x100 || (addr > 0xd00 && addr != 0xf00)) { nvic_writel(s->nvic, addr, value); return; } #endif if (offset == 0xf00) { int cpu; int irq; int mask; cpu = gic_get_current_cpu(); irq = value & 0x3ff; switch ((value >> 24) & 3) { case 0: mask = (value >> 16) & ALL_CPU_MASK; break; case 1: mask = 1 << cpu; break; case 2: mask = ALL_CPU_MASK ^ (1 << cpu); break; default: DPRINTF("Bad Soft Int target filter\n"); mask = ALL_CPU_MASK; break; } GIC_SET_PENDING(irq, mask); gic_update(s); return; } gic_dist_writew(opaque, offset, value & 0xffff); gic_dist_writew(opaque, offset + 2, value >> 16); } static CPUReadMemoryFunc *gic_dist_readfn[] = { gic_dist_readb, gic_dist_readw, gic_dist_readl }; static CPUWriteMemoryFunc *gic_dist_writefn[] = { gic_dist_writeb, gic_dist_writew, gic_dist_writel }; #ifndef NVIC static uint32_t gic_cpu_read(gic_state *s, int cpu, int offset) { switch (offset) { case 0x00: /* Control */ return s->cpu_enabled[cpu]; case 0x04: /* Priority mask */ return s->priority_mask[cpu]; case 0x08: /* Binary Point */ /* ??? Not implemented. */ return 0; case 0x0c: /* Acknowledge */ return gic_acknowledge_irq(s, cpu); case 0x14: /* Runing Priority */ return s->running_priority[cpu]; case 0x18: /* Highest Pending Interrupt */ return s->current_pending[cpu]; default: hw_error("gic_cpu_read: Bad offset %x\n", (int)offset); return 0; } } static void gic_cpu_write(gic_state *s, int cpu, int offset, uint32_t value) { switch (offset) { case 0x00: /* Control */ s->cpu_enabled[cpu] = (value & 1); DPRINTF("CPU %sabled\n", s->cpu_enabled ? "En" : "Dis"); break; case 0x04: /* Priority mask */ s->priority_mask[cpu] = (value & 0xff); break; case 0x08: /* Binary Point */ /* ??? Not implemented. */ break; case 0x10: /* End Of Interrupt */ return gic_complete_irq(s, cpu, value & 0x3ff); default: hw_error("gic_cpu_write: Bad offset %x\n", (int)offset); return; } gic_update(s); } #endif static void gic_reset(gic_state *s) { int i; memset(s->irq_state, 0, GIC_NIRQ * sizeof(gic_irq_state)); for (i = 0 ; i < NCPU; i++) { s->priority_mask[i] = 0xf0; s->current_pending[i] = 1023; s->running_irq[i] = 1023; s->running_priority[i] = 0x100; #ifdef NVIC /* The NVIC doesn't have per-cpu interfaces, so enable by default. */ s->cpu_enabled[i] = 1; #else s->cpu_enabled[i] = 0; #endif } for (i = 0; i < 16; i++) { GIC_SET_ENABLED(i); GIC_SET_TRIGGER(i); } #ifdef NVIC /* The NVIC is always enabled. */ s->enabled = 1; #else s->enabled = 0; #endif } static void gic_save(QEMUFile *f, void *opaque) { gic_state *s = (gic_state *)opaque; int i; int j; qemu_put_be32(f, s->enabled); for (i = 0; i < NCPU; i++) { qemu_put_be32(f, s->cpu_enabled[i]); #ifndef NVIC qemu_put_be32(f, s->irq_target[i]); #endif for (j = 0; j < 32; j++) qemu_put_be32(f, s->priority1[j][i]); for (j = 0; j < GIC_NIRQ; j++) qemu_put_be32(f, s->last_active[j][i]); qemu_put_be32(f, s->priority_mask[i]); qemu_put_be32(f, s->running_irq[i]); qemu_put_be32(f, s->running_priority[i]); qemu_put_be32(f, s->current_pending[i]); } for (i = 0; i < GIC_NIRQ - 32; i++) { qemu_put_be32(f, s->priority2[i]); } for (i = 0; i < GIC_NIRQ; i++) { qemu_put_byte(f, s->irq_state[i].enabled); qemu_put_byte(f, s->irq_state[i].pending); qemu_put_byte(f, s->irq_state[i].active); qemu_put_byte(f, s->irq_state[i].level); qemu_put_byte(f, s->irq_state[i].model); qemu_put_byte(f, s->irq_state[i].trigger); } } static int gic_load(QEMUFile *f, void *opaque, int version_id) { gic_state *s = (gic_state *)opaque; int i; int j; if (version_id != 1) return -EINVAL; s->enabled = qemu_get_be32(f); for (i = 0; i < NCPU; i++) { s->cpu_enabled[i] = qemu_get_be32(f); #ifndef NVIC s->irq_target[i] = qemu_get_be32(f); #endif for (j = 0; j < 32; j++) s->priority1[j][i] = qemu_get_be32(f); for (j = 0; j < GIC_NIRQ; j++) s->last_active[j][i] = qemu_get_be32(f); s->priority_mask[i] = qemu_get_be32(f); s->running_irq[i] = qemu_get_be32(f); s->running_priority[i] = qemu_get_be32(f); s->current_pending[i] = qemu_get_be32(f); } for (i = 0; i < GIC_NIRQ - 32; i++) { s->priority2[i] = qemu_get_be32(f); } for (i = 0; i < GIC_NIRQ; i++) { s->irq_state[i].enabled = qemu_get_byte(f); s->irq_state[i].pending = qemu_get_byte(f); s->irq_state[i].active = qemu_get_byte(f); s->irq_state[i].level = qemu_get_byte(f); s->irq_state[i].model = qemu_get_byte(f); s->irq_state[i].trigger = qemu_get_byte(f); } return 0; } static gic_state *gic_init(uint32_t dist_base, qemu_irq *parent_irq) { gic_state *s; int iomemtype; int i; s = (gic_state *)qemu_mallocz(sizeof(gic_state)); s->in = qemu_allocate_irqs(gic_set_irq, s, GIC_NIRQ); for (i = 0; i < NCPU; i++) { s->parent_irq[i] = parent_irq[i]; } iomemtype = cpu_register_io_memory(0, gic_dist_readfn, gic_dist_writefn, s); cpu_register_physical_memory(dist_base, 0x00001000, iomemtype); gic_reset(s); register_savevm("arm_gic", -1, 1, gic_save, gic_load, s); return s; }