[Qemu-devel] [PATCH v5 2/5] arm: make the number of GIC interrupts configurable

[Mark Langsdorf <mark.langsdorf@calxeda.com>]

Increase the maximum number of GIC interrupts for a9mp and a11mp to 256,
and create a configurable property for each defaulting to 96 and 64
(respectively) so that device modelers can set the value appropriately
for their SoC. Other ARM processors also set their maximum number of
used IRQs appropriately.

Set the maximum theoretically number of GIC interrupts to 1020 and
update the save/restore code to only use the appropriate number for
each SoC.

Signed-off-by: Mark Langsdorf <mark.langsdorf@calxeda.com>
---
Changes from v4, v5
        None
Changes from v3
        Increase maximum number of GIC interrupts to 1020
        Remove SoC/implementation specific GIC_NIRQ #defs
        Added properties code to arm11mp
        Changed error handling for too many interrupts
        Redid save/load handling
Changes from v2
        Skipped
Changes from v1
        Increase the number of a9mp interrupts to 192
        Add a property defaulting to 96
        Add a num_irq member in the gic state structure
        Use the num_irq value as appropriate
        Add num_irq argument to gic_init()
        Add num_irq to various CPU calls to gic_init

 hw/a9mpcore.c     |    7 +++--
 hw/arm11mpcore.c  |   14 +++++++-----
 hw/arm_gic.c      |   57 +++++++++++++++++++++++++++++-----------------------
 hw/armv7m_nvic.c  |    7 ++---
 hw/realview_gic.c |    3 +-
 5 files changed, 48 insertions(+), 40 deletions(-)

diff --git a/hw/a9mpcore.c b/hw/a9mpcore.c
index 3ef0e13..8c8b72b 100644
--- a/hw/a9mpcore.c
+++ b/hw/a9mpcore.c
@@ -11,9 +11,8 @@
 #include "sysbus.h"
 
 /* Configuration for arm_gic.c:
- * number of external IRQ lines, max number of CPUs, how to ID current CPU
+ * max number of CPUs, how to ID current CPU
  */
-#define GIC_NIRQ 96
 #define NCPU 4
 
 static inline int
@@ -37,6 +36,7 @@ typedef struct a9mp_priv_state {
     MemoryRegion ptimer_iomem;
     MemoryRegion container;
     DeviceState *mptimer;
+    uint32_t num_irq;
 } a9mp_priv_state;
 
 static uint64_t a9_scu_read(void *opaque, target_phys_addr_t offset,
@@ -153,7 +153,7 @@ static int a9mp_priv_init(SysBusDevice *dev)
         hw_error("a9mp_priv_init: num-cpu may not be more than %d\n", NCPU);
     }
 
-    gic_init(&s->gic, s->num_cpu);
+    gic_init(&s->gic, s->num_cpu, s->num_irq);
 
     s->mptimer = qdev_create(NULL, "arm_mptimer");
     qdev_prop_set_uint32(s->mptimer, "num-cpu", s->num_cpu);
@@ -216,6 +216,7 @@ static SysBusDeviceInfo a9mp_priv_info = {
     .qdev.reset = a9mp_priv_reset,
     .qdev.props = (Property[]) {
         DEFINE_PROP_UINT32("num-cpu", a9mp_priv_state, num_cpu, 1),
+        DEFINE_PROP_UINT32("num-irq", a9mp_priv_state, num_irq, 256),
         DEFINE_PROP_END_OF_LIST(),
     }
 };
diff --git a/hw/arm11mpcore.c b/hw/arm11mpcore.c
index bc0457e..e4e4bb3 100644
--- a/hw/arm11mpcore.c
+++ b/hw/arm11mpcore.c
@@ -10,11 +10,6 @@
 #include "sysbus.h"
 #include "qemu-timer.h"
 
-/* ??? The MPCore TRM says the on-chip controller has 224 external IRQ lines
-   (+ 32 internal).  However my test chip only exposes/reports 32.
-   More importantly Linux falls over if more than 32 are present!  */
-#define GIC_NIRQ 64
-
 #define NCPU 4
 
 static inline int
@@ -37,6 +32,7 @@ typedef struct mpcore_priv_state {
     MemoryRegion iomem;
     MemoryRegion container;
     DeviceState *mptimer;
+    uint32_t num_irq;
 } mpcore_priv_state;
 
 /* Per-CPU private memory mapped IO.  */
@@ -132,7 +128,7 @@ static int mpcore_priv_init(SysBusDevice *dev)
 {
     mpcore_priv_state *s = FROM_SYSBUSGIC(mpcore_priv_state, dev);
 
-    gic_init(&s->gic, s->num_cpu);
+    gic_init(&s->gic, s->num_cpu, GIC_NIRQ);
     s->mptimer = qdev_create(NULL, "arm_mptimer");
     qdev_prop_set_uint32(s->mptimer, "num-cpu", s->num_cpu);
     qdev_init_nofail(s->mptimer);
@@ -221,6 +217,12 @@ static SysBusDeviceInfo mpcore_priv_info = {
     .qdev.size  = sizeof(mpcore_priv_state),
     .qdev.props = (Property[]) {
         DEFINE_PROP_UINT32("num-cpu", mpcore_priv_state, num_cpu, 1),
+        /* The MPCore TRM says the on-chip controller has 224 external
+         * IRQ lines (+ 32 internal).  Some test chips only
+         * expose/report 32. More importantly Linux falls over if more
+         * than 32 are present!  Set the default to 64 and let chips
+         * with more working lines set it higher */
+        DEFINE_PROP_UINT32("num-irq", mpcore_priv_state, num_irq, 64),
         DEFINE_PROP_END_OF_LIST(),
     }
 };
diff --git a/hw/arm_gic.c b/hw/arm_gic.c
index 0339cf5..5bfb01f 100644
--- a/hw/arm_gic.c
+++ b/hw/arm_gic.c
@@ -11,6 +11,7 @@
    controller, MPCore distributed interrupt controller and ARMv7-M
    Nested Vectored Interrupt Controller.  */
 
+#define GIC_NIRQ 1020
 //#define DEBUG_GIC
 
 #ifdef DEBUG_GIC
@@ -111,6 +112,7 @@ typedef struct gic_state
     struct gic_state *backref[NCPU];
     MemoryRegion cpuiomem[NCPU+1]; /* CPU interfaces */
 #endif
+    int num_irq;
 } gic_state;
 
 /* TODO: Many places that call this routine could be optimized.  */
@@ -133,7 +135,7 @@ static void gic_update(gic_state *s)
         }
         best_prio = 0x100;
         best_irq = 1023;
-        for (irq = 0; irq < GIC_NIRQ; irq++) {
+        for (irq = 0; irq < s->num_irq; irq++) {
             if (GIC_TEST_ENABLED(irq, cm) && GIC_TEST_PENDING(irq, cm)) {
                 if (GIC_GET_PRIORITY(irq, cpu) < best_prio) {
                     best_prio = GIC_GET_PRIORITY(irq, cpu);
@@ -222,7 +224,7 @@ 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 (irq >= GIC_NIRQ) {
+    if (irq >= s->num_irq) {
         /* This handles two cases:
          * 1. If software writes the ID of a spurious interrupt [ie 1023]
          * to the GICC_EOIR, the GIC ignores that write.
@@ -279,7 +281,7 @@ static uint32_t gic_dist_readb(void *opaque, target_phys_addr_t offset)
         if (offset == 0)
             return s->enabled;
         if (offset == 4)
-            return ((GIC_NIRQ / 32) - 1) | ((NUM_CPU(s) - 1) << 5);
+            return ((s->num_irq / 32) - 1) | ((NUM_CPU(s) - 1) << 5);
         if (offset < 0x08)
             return 0;
         if (offset >= 0x80) {
@@ -295,7 +297,7 @@ static uint32_t gic_dist_readb(void *opaque, target_phys_addr_t offset)
         else
             irq = (offset - 0x180) * 8;
         irq += GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             goto bad_reg;
         res = 0;
         for (i = 0; i < 8; i++) {
@@ -310,7 +312,7 @@ static uint32_t gic_dist_readb(void *opaque, target_phys_addr_t offset)
         else
             irq = (offset - 0x280) * 8;
         irq += GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             goto bad_reg;
         res = 0;
         mask = (irq < 32) ?  cm : ALL_CPU_MASK;
@@ -322,7 +324,7 @@ static uint32_t gic_dist_readb(void *opaque, target_phys_addr_t offset)
     } else if (offset < 0x400) {
         /* Interrupt Active.  */
         irq = (offset - 0x300) * 8 + GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             goto bad_reg;
         res = 0;
         mask = (irq < 32) ?  cm : ALL_CPU_MASK;
@@ -334,14 +336,14 @@ static uint32_t gic_dist_readb(void *opaque, target_phys_addr_t offset)
     } else if (offset < 0x800) {
         /* Interrupt Priority.  */
         irq = (offset - 0x400) + GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             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)
+        if (irq >= s->num_irq)
             goto bad_reg;
         if (irq >= 29 && irq <= 31) {
             res = cm;
@@ -351,7 +353,7 @@ static uint32_t gic_dist_readb(void *opaque, target_phys_addr_t offset)
     } else if (offset < 0xf00) {
         /* Interrupt Configuration.  */
         irq = (offset - 0xc00) * 2 + GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             goto bad_reg;
         res = 0;
         for (i = 0; i < 4; i++) {
@@ -426,7 +428,7 @@ static void gic_dist_writeb(void *opaque, target_phys_addr_t offset,
     } else if (offset < 0x180) {
         /* Interrupt Set Enable.  */
         irq = (offset - 0x100) * 8 + GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             goto bad_reg;
         if (irq < 16)
           value = 0xff;
@@ -451,7 +453,7 @@ static void gic_dist_writeb(void *opaque, target_phys_addr_t offset,
     } else if (offset < 0x200) {
         /* Interrupt Clear Enable.  */
         irq = (offset - 0x180) * 8 + GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             goto bad_reg;
         if (irq < 16)
           value = 0;
@@ -468,7 +470,7 @@ static void gic_dist_writeb(void *opaque, target_phys_addr_t offset,
     } else if (offset < 0x280) {
         /* Interrupt Set Pending.  */
         irq = (offset - 0x200) * 8 + GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             goto bad_reg;
         if (irq < 16)
           irq = 0;
@@ -481,7 +483,7 @@ static void gic_dist_writeb(void *opaque, target_phys_addr_t offset,
     } else if (offset < 0x300) {
         /* Interrupt Clear Pending.  */
         irq = (offset - 0x280) * 8 + GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             goto bad_reg;
         for (i = 0; i < 8; i++) {
             /* ??? This currently clears the pending bit for all CPUs, even
@@ -497,7 +499,7 @@ static void gic_dist_writeb(void *opaque, target_phys_addr_t offset,
     } else if (offset < 0x800) {
         /* Interrupt Priority.  */
         irq = (offset - 0x400) + GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             goto bad_reg;
         if (irq < 32) {
             s->priority1[irq][cpu] = value;
@@ -508,7 +510,7 @@ static void gic_dist_writeb(void *opaque, target_phys_addr_t offset,
     } else if (offset < 0xc00) {
         /* Interrupt CPU Target.  */
         irq = (offset - 0x800) + GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             goto bad_reg;
         if (irq < 29)
             value = 0;
@@ -518,7 +520,7 @@ static void gic_dist_writeb(void *opaque, target_phys_addr_t offset,
     } else if (offset < 0xf00) {
         /* Interrupt Configuration.  */
         irq = (offset - 0xc00) * 4 + GIC_BASE_IRQ;
-        if (irq >= GIC_NIRQ)
+        if (irq >= s->num_irq)
             goto bad_reg;
         if (irq < 32)
             value |= 0xaa;
@@ -735,17 +737,17 @@ static void gic_save(QEMUFile *f, void *opaque)
         qemu_put_be32(f, s->cpu_enabled[i]);
         for (j = 0; j < 32; j++)
             qemu_put_be32(f, s->priority1[j][i]);
-        for (j = 0; j < GIC_NIRQ; j++)
+        for (j = 0; j < s->num_irq; 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++) {
+    for (i = 0; i < s->num_irq - 32; i++) {
         qemu_put_be32(f, s->priority2[i]);
     }
-    for (i = 0; i < GIC_NIRQ; i++) {
+    for (i = 0; i < s->num_irq; i++) {
 #ifndef NVIC
         qemu_put_be32(f, s->irq_target[i]);
 #endif
@@ -772,17 +774,17 @@ static int gic_load(QEMUFile *f, void *opaque, int version_id)
         s->cpu_enabled[i] = qemu_get_be32(f);
         for (j = 0; j < 32; j++)
             s->priority1[j][i] = qemu_get_be32(f);
-        for (j = 0; j < GIC_NIRQ; j++)
+        for (j = 0; j < s->num_irq; 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++) {
+    for (i = 0; i < s->num_irq - 32; i++) {
         s->priority2[i] = qemu_get_be32(f);
     }
-    for (i = 0; i < GIC_NIRQ; i++) {
+    for (i = 0; i < s->num_irq; i++) {
 #ifndef NVIC
         s->irq_target[i] = qemu_get_be32(f);
 #endif
@@ -798,9 +800,9 @@ static int gic_load(QEMUFile *f, void *opaque, int version_id)
 }
 
 #if NCPU > 1
-static void gic_init(gic_state *s, int num_cpu)
+static void gic_init(gic_state *s, int num_cpu, int num_irq)
 #else
-static void gic_init(gic_state *s)
+static void gic_init(gic_state *s, int num_irq)
 #endif
 {
     int i;
@@ -808,7 +810,12 @@ static void gic_init(gic_state *s)
 #if NCPU > 1
     s->num_cpu = num_cpu;
 #endif
-    qdev_init_gpio_in(&s->busdev.qdev, gic_set_irq, GIC_NIRQ - 32);
+    s->num_irq = num_irq;
+    if (s->num_irq > GIC_NIRQ) {
+        hw_error("device requested %u out of %u interrupt lines, failing\n",
+                 num_irq, GIC_NIRQ);
+    }
+    qdev_init_gpio_in(&s->busdev.qdev, gic_set_irq, s->num_irq - 32);
     for (i = 0; i < NUM_CPU(s); i++) {
         sysbus_init_irq(&s->busdev, &s->parent_irq[i]);
     }
diff --git a/hw/armv7m_nvic.c b/hw/armv7m_nvic.c
index bf8c3c5..0de51f4 100644
--- a/hw/armv7m_nvic.c
+++ b/hw/armv7m_nvic.c
@@ -15,9 +15,6 @@
 #include "arm-misc.h"
 #include "exec-memory.h"
 
-/* 32 internal lines (16 used for system exceptions) plus 64 external
-   interrupt lines.  */
-#define GIC_NIRQ 96
 #define NCPU 1
 #define NVIC 1
 
@@ -384,7 +381,9 @@ static int armv7m_nvic_init(SysBusDevice *dev)
 {
     nvic_state *s= FROM_SYSBUSGIC(nvic_state, dev);
 
-    gic_init(&s->gic);
+   /* 32 internal lines (16 used for system exceptions) plus 64 external
+    * interrupt lines.  */
+    gic_init(&s->gic, 96);
     memory_region_add_subregion(get_system_memory(), 0xe000e000, &s->gic.iomem);
     s->systick.timer = qemu_new_timer_ns(vm_clock, systick_timer_tick, s);
     vmstate_register(&dev->qdev, -1, &vmstate_nvic, s);
diff --git a/hw/realview_gic.c b/hw/realview_gic.c
index 8c4d509..cd7e53d 100644
--- a/hw/realview_gic.c
+++ b/hw/realview_gic.c
@@ -9,7 +9,6 @@
 
 #include "sysbus.h"
 
-#define GIC_NIRQ 96
 #define NCPU 1
 
 /* Only a single "CPU" interface is present.  */
@@ -37,7 +36,7 @@ static int realview_gic_init(SysBusDevice *dev)
 {
     RealViewGICState *s = FROM_SYSBUSGIC(RealViewGICState, dev);
 
-    gic_init(&s->gic);
+    gic_init(&s->gic, 96);
     realview_gic_map_setup(s);
     sysbus_init_mmio(dev, &s->container);
     return 0;
-- 
1.7.5.4