Introduce a model of Xilinx Versal's Configuration Frame Unit's data out
port (CFU_FDRO).

Signed-off-by: Francisco Iglesias <francisco.iglesias@amd.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/misc/xlnx-versal-cfu.c         | 96 +++++++++++++++++++++++++++++++
 include/hw/misc/xlnx-versal-cfu.h | 12 ++++
 2 files changed, 108 insertions(+)

diff --git a/hw/misc/xlnx-versal-cfu.c b/hw/misc/xlnx-versal-cfu.c
index b2dc6ab211..255c1bf4b8 100644
--- a/hw/misc/xlnx-versal-cfu.c
+++ b/hw/misc/xlnx-versal-cfu.c
@@ -264,6 +264,25 @@ static void cfu_stream_write(void *opaque, hwaddr addr, uint64_t value,
     }
 }
 
+static uint64_t cfu_fdro_read(void *opaque, hwaddr addr, unsigned size)
+{
+    XlnxVersalCFUFDRO *s = XLNX_VERSAL_CFU_FDRO(opaque);
+    uint64_t ret = 0;
+
+    if (!fifo32_is_empty(&s->fdro_data)) {
+        ret = fifo32_pop(&s->fdro_data);
+    }
+
+    return ret;
+}
+
+static void cfu_fdro_write(void *opaque, hwaddr addr, uint64_t value,
+                           unsigned size)
+{
+    qemu_log_mask(LOG_GUEST_ERROR, "%s: Unsupported write from addr=%"
+                  HWADDR_PRIx "\n", __func__, addr);
+}
+
 static const MemoryRegionOps cfu_stream_ops = {
     .read = cfu_stream_read,
     .write = cfu_stream_write,
@@ -274,6 +293,16 @@ static const MemoryRegionOps cfu_stream_ops = {
     },
 };
 
+static const MemoryRegionOps cfu_fdro_ops = {
+    .read = cfu_fdro_read,
+    .write = cfu_fdro_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .valid = {
+        .min_access_size = 4,
+        .max_access_size = 4,
+    },
+};
+
 static void cfu_apb_init(Object *obj)
 {
     XlnxVersalCFUAPB *s = XLNX_VERSAL_CFU_APB(obj);
@@ -305,6 +334,39 @@ static void cfu_apb_init(Object *obj)
     sysbus_init_irq(sbd, &s->irq_cfu_imr);
 }
 
+static void cfu_fdro_init(Object *obj)
+{
+    XlnxVersalCFUFDRO *s = XLNX_VERSAL_CFU_FDRO(obj);
+    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+
+    memory_region_init_io(&s->iomem_fdro, obj, &cfu_fdro_ops, s,
+                          TYPE_XLNX_VERSAL_CFU_FDRO, KEYHOLE_STREAM_4K);
+    sysbus_init_mmio(sbd, &s->iomem_fdro);
+    fifo32_create(&s->fdro_data, 8 * KiB / sizeof(uint32_t));
+}
+
+static void cfu_fdro_reset_enter(Object *obj, ResetType type)
+{
+    XlnxVersalCFUFDRO *s = XLNX_VERSAL_CFU_FDRO(obj);
+
+    fifo32_reset(&s->fdro_data);
+}
+
+static void cfu_fdro_cfi_transfer_packet(XlnxCfiIf *cfi_if, XlnxCfiPacket *pkt)
+{
+    XlnxVersalCFUFDRO *s = XLNX_VERSAL_CFU_FDRO(cfi_if);
+
+    if (fifo32_num_free(&s->fdro_data) >= ARRAY_SIZE(pkt->data)) {
+        for (int i = 0; i < ARRAY_SIZE(pkt->data); i++) {
+            fifo32_push(&s->fdro_data, pkt->data[i]);
+        }
+    } else {
+        /* It is a programming error to fill the fifo. */
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "CFU_FDRO: CFI data dropped due to full read fifo\n");
+    }
+}
+
 static Property cfu_props[] = {
         DEFINE_PROP_LINK("cframe0", XlnxVersalCFUAPB, cfg.cframe[0],
                          TYPE_XLNX_CFI_IF, XlnxCfiIf *),
@@ -351,6 +413,16 @@ static const VMStateDescription vmstate_cfu_apb = {
     }
 };
 
+static const VMStateDescription vmstate_cfu_fdro = {
+    .name = TYPE_XLNX_VERSAL_CFU_FDRO,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_FIFO32(fdro_data, XlnxVersalCFUFDRO),
+        VMSTATE_END_OF_LIST(),
+    }
+};
+
 static void cfu_apb_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -360,6 +432,17 @@ static void cfu_apb_class_init(ObjectClass *klass, void *data)
     device_class_set_props(dc, cfu_props);
 }
 
+static void cfu_fdro_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    ResettableClass *rc = RESETTABLE_CLASS(klass);
+    XlnxCfiIfClass *xcic = XLNX_CFI_IF_CLASS(klass);
+
+    dc->vmsd = &vmstate_cfu_fdro;
+    xcic->cfi_transfer_packet = cfu_fdro_cfi_transfer_packet;
+    rc->phases.enter = cfu_fdro_reset_enter;
+}
+
 static const TypeInfo cfu_apb_info = {
     .name          = TYPE_XLNX_VERSAL_CFU_APB,
     .parent        = TYPE_SYS_BUS_DEVICE,
@@ -372,9 +455,22 @@ static const TypeInfo cfu_apb_info = {
     }
 };
 
+static const TypeInfo cfu_fdro_info = {
+    .name          = TYPE_XLNX_VERSAL_CFU_FDRO,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(XlnxVersalCFUFDRO),
+    .class_init    = cfu_fdro_class_init,
+    .instance_init = cfu_fdro_init,
+    .interfaces = (InterfaceInfo[]) {
+        { TYPE_XLNX_CFI_IF },
+        { }
+    }
+};
+
 static void cfu_apb_register_types(void)
 {
     type_register_static(&cfu_apb_info);
+    type_register_static(&cfu_fdro_info);
 }
 
 type_init(cfu_apb_register_types)
diff --git a/include/hw/misc/xlnx-versal-cfu.h b/include/hw/misc/xlnx-versal-cfu.h
index 62d10caf27..73e9a21af4 100644
--- a/include/hw/misc/xlnx-versal-cfu.h
+++ b/include/hw/misc/xlnx-versal-cfu.h
@@ -20,10 +20,14 @@
 #include "hw/sysbus.h"
 #include "hw/register.h"
 #include "hw/misc/xlnx-cfi-if.h"
+#include "qemu/fifo32.h"
 
 #define TYPE_XLNX_VERSAL_CFU_APB "xlnx,versal-cfu-apb"
 OBJECT_DECLARE_SIMPLE_TYPE(XlnxVersalCFUAPB, XLNX_VERSAL_CFU_APB)
 
+#define TYPE_XLNX_VERSAL_CFU_FDRO "xlnx,versal-cfu-fdro"
+OBJECT_DECLARE_SIMPLE_TYPE(XlnxVersalCFUFDRO, XLNX_VERSAL_CFU_FDRO)
+
 REG32(CFU_ISR, 0x0)
     FIELD(CFU_ISR, USR_GTS_EVENT, 9, 1)
     FIELD(CFU_ISR, USR_GSR_EVENT, 8, 1)
@@ -210,6 +214,14 @@ struct XlnxVersalCFUAPB {
     } cfg;
 };
 
+
+struct XlnxVersalCFUFDRO {
+    SysBusDevice parent_obj;
+    MemoryRegion iomem_fdro;
+
+    Fifo32 fdro_data;
+};
+
 /**
  * This is a helper function for updating a CFI data write fifo, an array of 4
  * uint32_t and 128 bits of data that are allowed to be written through 4
-- 
2.34.1