bcm2836_control: add bcm2836 ARM control logic

This module is specific to the bcm2836 (Pi2). It implements the top
level interrupt controller, and mailboxes used for inter-processor
synchronisation.

Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Andrew Baumann <Andrew.Baumann@microsoft.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

hw/intc/Makefile.objs

@@ -24,7 +24,7 @@ obj-$(CONFIG_GRLIB) += grlib_irqmp.o
 obj-$(CONFIG_IOAPIC) += ioapic.o
 obj-$(CONFIG_OMAP) += omap_intc.o
 obj-$(CONFIG_OPENPIC_KVM) += openpic_kvm.o
-obj-$(CONFIG_RASPI) += bcm2835_ic.o
+obj-$(CONFIG_RASPI) += bcm2835_ic.o bcm2836_control.o
 obj-$(CONFIG_SH4) += sh_intc.o
 obj-$(CONFIG_XICS) += xics.o
 obj-$(CONFIG_XICS_KVM) += xics_kvm.o

hw/intc/bcm2836_control.c

@@ -0,0 +1,303 @@
+/*
+ * Rasperry Pi 2 emulation ARM control logic module.
+ * Copyright (c) 2015, Microsoft
+ * Written by Andrew Baumann
+ *
+ * Based on bcm2835_ic.c (Raspberry Pi emulation) (c) 2012 Gregory Estrade
+ * This code is licensed under the GNU GPLv2 and later.
+ *
+ * At present, only implements interrupt routing, and mailboxes (i.e.,
+ * not local timer, PMU interrupt, or AXI counters).
+ *
+ * Ref:
+ * https://www.raspberrypi.org/documentation/hardware/raspberrypi/bcm2836/QA7_rev3.4.pdf
+ */
+
+#include "hw/intc/bcm2836_control.h"
+
+#define REG_GPU_ROUTE           0x0c
+#define REG_TIMERCONTROL        0x40
+#define REG_MBOXCONTROL         0x50
+#define REG_IRQSRC              0x60
+#define REG_FIQSRC              0x70
+#define REG_MBOX0_WR            0x80
+#define REG_MBOX0_RDCLR         0xc0
+#define REG_LIMIT              0x100
+
+#define IRQ_BIT(cntrl, num) (((cntrl) & (1 << (num))) != 0)
+#define FIQ_BIT(cntrl, num) (((cntrl) & (1 << ((num) + 4))) != 0)
+
+#define IRQ_CNTPSIRQ    0
+#define IRQ_CNTPNSIRQ   1
+#define IRQ_CNTHPIRQ    2
+#define IRQ_CNTVIRQ     3
+#define IRQ_MAILBOX0    4
+#define IRQ_MAILBOX1    5
+#define IRQ_MAILBOX2    6
+#define IRQ_MAILBOX3    7
+#define IRQ_GPU         8
+#define IRQ_PMU         9
+#define IRQ_AXI         10
+#define IRQ_TIMER       11
+#define IRQ_MAX         IRQ_TIMER
+
+static void deliver_local(BCM2836ControlState *s, uint8_t core, uint8_t irq,
+                          uint32_t controlreg, uint8_t controlidx)
+{
+    if (FIQ_BIT(controlreg, controlidx)) {
+        /* deliver a FIQ */
+        s->fiqsrc[core] |= (uint32_t)1 << irq;
+    } else if (IRQ_BIT(controlreg, controlidx)) {
+        /* deliver an IRQ */
+        s->irqsrc[core] |= (uint32_t)1 << irq;
+    } else {
+        /* the interrupt is masked */
+    }
+}
+
+/* Update interrupts.  */
+static void bcm2836_control_update(BCM2836ControlState *s)
+{
+    int i, j;
+
+    /* reset pending IRQs/FIQs */
+    for (i = 0; i < BCM2836_NCORES; i++) {
+        s->irqsrc[i] = s->fiqsrc[i] = 0;
+    }
+
+    /* apply routing logic, update status regs */
+    if (s->gpu_irq) {
+        assert(s->route_gpu_irq < BCM2836_NCORES);
+        s->irqsrc[s->route_gpu_irq] |= (uint32_t)1 << IRQ_GPU;
+    }
+
+    if (s->gpu_fiq) {
+        assert(s->route_gpu_fiq < BCM2836_NCORES);
+        s->fiqsrc[s->route_gpu_fiq] |= (uint32_t)1 << IRQ_GPU;
+    }
+
+    for (i = 0; i < BCM2836_NCORES; i++) {
+        /* handle local timer interrupts for this core */
+        if (s->timerirqs[i]) {
+            assert(s->timerirqs[i] < (1 << (IRQ_CNTVIRQ + 1))); /* sane mask? */
+            for (j = 0; j <= IRQ_CNTVIRQ; j++) {
+                if ((s->timerirqs[i] & (1 << j)) != 0) {
+                    /* local interrupt j is set */
+                    deliver_local(s, i, j, s->timercontrol[i], j);
+                }
+            }
+        }
+
+        /* handle mailboxes for this core */
+        for (j = 0; j < BCM2836_MBPERCORE; j++) {
+            if (s->mailboxes[i * BCM2836_MBPERCORE + j] != 0) {
+                /* mailbox j is set */
+                deliver_local(s, i, j + IRQ_MAILBOX0, s->mailboxcontrol[i], j);
+            }
+        }
+    }
+
+    /* call set_irq appropriately for each output */
+    for (i = 0; i < BCM2836_NCORES; i++) {
+        qemu_set_irq(s->irq[i], s->irqsrc[i] != 0);
+        qemu_set_irq(s->fiq[i], s->fiqsrc[i] != 0);
+    }
+}
+
+static void bcm2836_control_set_local_irq(void *opaque, int core, int local_irq,
+                                          int level)
+{
+    BCM2836ControlState *s = opaque;
+
+    assert(core >= 0 && core < BCM2836_NCORES);
+    assert(local_irq >= 0 && local_irq <= IRQ_CNTVIRQ);
+
+    s->timerirqs[core] = deposit32(s->timerirqs[core], local_irq, 1, !!level);
+
+    bcm2836_control_update(s);
+}
+
+/* XXX: the following wrapper functions are a kludgy workaround,
+ * needed because I can't seem to pass useful information in the "irq"
+ * parameter when using named interrupts. Feel free to clean this up!
+ */
+
+static void bcm2836_control_set_local_irq0(void *opaque, int core, int level)
+{
+    bcm2836_control_set_local_irq(opaque, core, 0, level);
+}
+
+static void bcm2836_control_set_local_irq1(void *opaque, int core, int level)
+{
+    bcm2836_control_set_local_irq(opaque, core, 1, level);
+}
+
+static void bcm2836_control_set_local_irq2(void *opaque, int core, int level)
+{
+    bcm2836_control_set_local_irq(opaque, core, 2, level);
+}
+
+static void bcm2836_control_set_local_irq3(void *opaque, int core, int level)
+{
+    bcm2836_control_set_local_irq(opaque, core, 3, level);
+}
+
+static void bcm2836_control_set_gpu_irq(void *opaque, int irq, int level)
+{
+    BCM2836ControlState *s = opaque;
+
+    s->gpu_irq = level;
+
+    bcm2836_control_update(s);
+}
+
+static void bcm2836_control_set_gpu_fiq(void *opaque, int irq, int level)
+{
+    BCM2836ControlState *s = opaque;
+
+    s->gpu_fiq = level;
+
+    bcm2836_control_update(s);
+}
+
+static uint64_t bcm2836_control_read(void *opaque, hwaddr offset, unsigned size)
+{
+    BCM2836ControlState *s = opaque;
+
+    if (offset == REG_GPU_ROUTE) {
+        assert(s->route_gpu_fiq < BCM2836_NCORES
+               && s->route_gpu_irq < BCM2836_NCORES);
+        return ((uint32_t)s->route_gpu_fiq << 2) | s->route_gpu_irq;
+    } else if (offset >= REG_TIMERCONTROL && offset < REG_MBOXCONTROL) {
+        return s->timercontrol[(offset - REG_TIMERCONTROL) >> 2];
+    } else if (offset >= REG_MBOXCONTROL && offset < REG_IRQSRC) {
+        return s->mailboxcontrol[(offset - REG_MBOXCONTROL) >> 2];
+    } else if (offset >= REG_IRQSRC && offset < REG_FIQSRC) {
+        return s->irqsrc[(offset - REG_IRQSRC) >> 2];
+    } else if (offset >= REG_FIQSRC && offset < REG_MBOX0_WR) {
+        return s->fiqsrc[(offset - REG_FIQSRC) >> 2];
+    } else if (offset >= REG_MBOX0_RDCLR && offset < REG_LIMIT) {
+        return s->mailboxes[(offset - REG_MBOX0_RDCLR) >> 2];
+    } else {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
+                      __func__, offset);
+        return 0;
+    }
+}
+
+static void bcm2836_control_write(void *opaque, hwaddr offset,
+                                  uint64_t val, unsigned size)
+{
+    BCM2836ControlState *s = opaque;
+
+    if (offset == REG_GPU_ROUTE) {
+        s->route_gpu_irq = val & 0x3;
+        s->route_gpu_fiq = (val >> 2) & 0x3;
+    } else if (offset >= REG_TIMERCONTROL && offset < REG_MBOXCONTROL) {
+        s->timercontrol[(offset - REG_TIMERCONTROL) >> 2] = val & 0xff;
+    } else if (offset >= REG_MBOXCONTROL && offset < REG_IRQSRC) {
+        s->mailboxcontrol[(offset - REG_MBOXCONTROL) >> 2] = val & 0xff;
+    } else if (offset >= REG_MBOX0_WR && offset < REG_MBOX0_RDCLR) {
+        s->mailboxes[(offset - REG_MBOX0_WR) >> 2] |= val;
+    } else if (offset >= REG_MBOX0_RDCLR && offset < REG_LIMIT) {
+        s->mailboxes[(offset - REG_MBOX0_RDCLR) >> 2] &= ~val;
+    } else {
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
+                      __func__, offset);
+        return;
+    }
+
+    bcm2836_control_update(s);
+}
+
+static const MemoryRegionOps bcm2836_control_ops = {
+    .read = bcm2836_control_read,
+    .write = bcm2836_control_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 4,
+};
+
+static void bcm2836_control_reset(DeviceState *d)
+{
+    BCM2836ControlState *s = BCM2836_CONTROL(d);
+    int i;
+
+    s->route_gpu_irq = s->route_gpu_fiq = 0;
+
+    for (i = 0; i < BCM2836_NCORES; i++) {
+        s->timercontrol[i] = 0;
+        s->mailboxcontrol[i] = 0;
+    }
+
+    for (i = 0; i < BCM2836_NCORES * BCM2836_MBPERCORE; i++) {
+        s->mailboxes[i] = 0;
+    }
+}
+
+static void bcm2836_control_init(Object *obj)
+{
+    BCM2836ControlState *s = BCM2836_CONTROL(obj);
+    DeviceState *dev = DEVICE(obj);
+
+    memory_region_init_io(&s->iomem, obj, &bcm2836_control_ops, s,
+                          TYPE_BCM2836_CONTROL, REG_LIMIT);
+    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
+
+    /* inputs from each CPU core */
+    qdev_init_gpio_in_named(dev, bcm2836_control_set_local_irq0, "cntpsirq",
+                            BCM2836_NCORES);
+    qdev_init_gpio_in_named(dev, bcm2836_control_set_local_irq1, "cntpnsirq",
+                            BCM2836_NCORES);
+    qdev_init_gpio_in_named(dev, bcm2836_control_set_local_irq2, "cnthpirq",
+                            BCM2836_NCORES);
+    qdev_init_gpio_in_named(dev, bcm2836_control_set_local_irq3, "cntvirq",
+                            BCM2836_NCORES);
+
+    /* IRQ and FIQ inputs from upstream bcm2835 controller */
+    qdev_init_gpio_in_named(dev, bcm2836_control_set_gpu_irq, "gpu-irq", 1);
+    qdev_init_gpio_in_named(dev, bcm2836_control_set_gpu_fiq, "gpu-fiq", 1);
+
+    /* outputs to CPU cores */
+    qdev_init_gpio_out_named(dev, s->irq, "irq", BCM2836_NCORES);
+    qdev_init_gpio_out_named(dev, s->fiq, "fiq", BCM2836_NCORES);
+}
+
+static const VMStateDescription vmstate_bcm2836_control = {
+    .name = TYPE_BCM2836_CONTROL,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32_ARRAY(mailboxes, BCM2836ControlState,
+                             BCM2836_NCORES * BCM2836_MBPERCORE),
+        VMSTATE_UINT8(route_gpu_irq, BCM2836ControlState),
+        VMSTATE_UINT8(route_gpu_fiq, BCM2836ControlState),
+        VMSTATE_UINT32_ARRAY(timercontrol, BCM2836ControlState, BCM2836_NCORES),
+        VMSTATE_UINT32_ARRAY(mailboxcontrol, BCM2836ControlState,
+                             BCM2836_NCORES),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void bcm2836_control_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->reset = bcm2836_control_reset;
+    dc->vmsd = &vmstate_bcm2836_control;
+}
+
+static TypeInfo bcm2836_control_info = {
+    .name          = TYPE_BCM2836_CONTROL,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(BCM2836ControlState),
+    .class_init    = bcm2836_control_class_init,
+    .instance_init = bcm2836_control_init,
+};
+
+static void bcm2836_control_register_types(void)
+{
+    type_register_static(&bcm2836_control_info);
+}
+
+type_init(bcm2836_control_register_types)

include/hw/intc/bcm2836_control.h

@@ -0,0 +1,51 @@
+/*
+ * Raspberry Pi emulation (c) 2012 Gregory Estrade
+ * Upstreaming code cleanup [including bcm2835_*] (c) 2013 Jan Petrous
+ *
+ * Rasperry Pi 2 emulation and refactoring Copyright (c) 2015, Microsoft
+ * Written by Andrew Baumann
+ *
+ * This code is licensed under the GNU GPLv2 and later.
+ */
+
+#ifndef BCM2836_CONTROL_H
+#define BCM2836_CONTROL_H
+
+#include "hw/sysbus.h"
+
+/* 4 mailboxes per core, for 16 total */
+#define BCM2836_NCORES 4
+#define BCM2836_MBPERCORE 4
+
+#define TYPE_BCM2836_CONTROL "bcm2836-control"
+#define BCM2836_CONTROL(obj) \
+    OBJECT_CHECK(BCM2836ControlState, (obj), TYPE_BCM2836_CONTROL)
+
+typedef struct BCM2836ControlState {
+    /*< private >*/
+    SysBusDevice busdev;
+    /*< public >*/
+    MemoryRegion iomem;
+
+    /* mailbox state */
+    uint32_t mailboxes[BCM2836_NCORES * BCM2836_MBPERCORE];
+
+    /* interrupt routing/control registers */
+    uint8_t route_gpu_irq, route_gpu_fiq;
+    uint32_t timercontrol[BCM2836_NCORES];
+    uint32_t mailboxcontrol[BCM2836_NCORES];
+
+    /* interrupt status regs (derived from input pins; not visible to user) */
+    bool gpu_irq, gpu_fiq;
+    uint8_t timerirqs[BCM2836_NCORES];
+
+    /* interrupt source registers, post-routing (also input-derived; visible) */
+    uint32_t irqsrc[BCM2836_NCORES];
+    uint32_t fiqsrc[BCM2836_NCORES];
+
+    /* outputs to CPU cores */
+    qemu_irq irq[BCM2836_NCORES];
+    qemu_irq fiq[BCM2836_NCORES];
+} BCM2836ControlState;
+
+#endif