hw/fsi: Introduce IBM's fsi-slave model

This is a part of patchset where IBM's Flexible Service Interface is
introduced.

The FSI slave: The slave is the terminal point of the FSI bus for
FSI symbols addressed to it. Slaves can be cascaded off of one
another. The slave's configuration registers appear in address space
of the CFAM to which it is attached.

Signed-off-by: Andrew Jeffery <andrew@aj.id.au>
Signed-off-by: Ninad Palsule <ninad@linux.ibm.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>

3 files changed, 102 insertions, 2 deletions

diff --git a/hw/fsi/fsi.c b/hw/fsi/fsi.c
index 60cb03f7a2..9a5f4e616f 100644
--- a/hw/fsi/fsi.c
+++ b/hw/fsi/fsi.c
@@ -5,18 +5,98 @@
  * IBM Flexible Service Interface
  */
 #include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "qemu/log.h"
+#include "trace.h"
 
 #include "hw/fsi/fsi.h"
 
+#define TO_REG(x)                               ((x) >> 2)
+
 static const TypeInfo fsi_bus_info = {
     .name = TYPE_FSI_BUS,
     .parent = TYPE_BUS,
     .instance_size = sizeof(FSIBus),
 };
 
-static void fsi_bus_register_types(void)
+static uint64_t fsi_slave_read(void *opaque, hwaddr addr, unsigned size)
+{
+    FSISlaveState *s = FSI_SLAVE(opaque);
+    int reg = TO_REG(addr);
+
+    trace_fsi_slave_read(addr, size);
+
+    if (reg >= FSI_SLAVE_CONTROL_NR_REGS) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Out of bounds read: 0x%"HWADDR_PRIx" for %u\n",
+                      __func__, addr, size);
+        return 0;
+    }
+
+    return s->regs[reg];
+}
+
+static void fsi_slave_write(void *opaque, hwaddr addr, uint64_t data,
+                                 unsigned size)
+{
+    FSISlaveState *s = FSI_SLAVE(opaque);
+    int reg = TO_REG(addr);
+
+    trace_fsi_slave_write(addr, size, data);
+
+    if (reg >= FSI_SLAVE_CONTROL_NR_REGS) {
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Out of bounds write: 0x%"HWADDR_PRIx" for %u\n",
+                      __func__, addr, size);
+        return;
+    }
+
+    s->regs[reg] = data;
+}
+
+static const struct MemoryRegionOps fsi_slave_ops = {
+    .read = fsi_slave_read,
+    .write = fsi_slave_write,
+    .endianness = DEVICE_BIG_ENDIAN,
+};
+
+static void fsi_slave_reset(DeviceState *dev)
+{
+    FSISlaveState *s = FSI_SLAVE(dev);
+
+    /* Initialize registers */
+    memset(s->regs, 0, sizeof(s->regs));
+}
+
+static void fsi_slave_init(Object *o)
+{
+    FSISlaveState *s = FSI_SLAVE(o);
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &fsi_slave_ops,
+                          s, TYPE_FSI_SLAVE, 0x400);
+}
+
+static void fsi_slave_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->bus_type = TYPE_FSI_BUS;
+    dc->desc = "FSI Slave";
+    dc->reset = fsi_slave_reset;
+}
+
+static const TypeInfo fsi_slave_info = {
+    .name = TYPE_FSI_SLAVE,
+    .parent = TYPE_DEVICE,
+    .instance_init = fsi_slave_init,
+    .instance_size = sizeof(FSISlaveState),
+    .class_init = fsi_slave_class_init,
+};
+
+static void fsi_register_types(void)
 {
     type_register_static(&fsi_bus_info);
+    type_register_static(&fsi_slave_info);
 }
 
-type_init(fsi_bus_register_types);
+type_init(fsi_register_types);
diff --git a/hw/fsi/trace-events b/hw/fsi/trace-events
index c5753e2791..8f29adb7df 100644
--- a/hw/fsi/trace-events
+++ b/hw/fsi/trace-events
@@ -1,2 +1,4 @@
 fsi_scratchpad_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
 fsi_scratchpad_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
+fsi_slave_read(uint64_t addr, uint32_t size) "@0x%" PRIx64 " size=%d"
+fsi_slave_write(uint64_t addr, uint32_t size, uint64_t data) "@0x%" PRIx64 " size=%d value=0x%"PRIx64
diff --git a/include/hw/fsi/fsi.h b/include/hw/fsi/fsi.h
index 50e8f5c888..e00f6ef078 100644
--- a/include/hw/fsi/fsi.h
+++ b/include/hw/fsi/fsi.h
@@ -7,7 +7,13 @@
 #ifndef FSI_FSI_H
 #define FSI_FSI_H
 
+#include "exec/memory.h"
 #include "hw/qdev-core.h"
+#include "hw/fsi/lbus.h"
+#include "qemu/bitops.h"
+
+/* Bitwise operations at the word level. */
+#define BE_GENMASK(hb, lb)  MAKE_64BIT_MASK((lb), ((hb) - (lb) + 1))
 
 #define TYPE_FSI_BUS "fsi.bus"
 OBJECT_DECLARE_SIMPLE_TYPE(FSIBus, FSI_BUS)
@@ -16,4 +22,16 @@ typedef struct FSIBus {
     BusState bus;
 } FSIBus;
 
+#define TYPE_FSI_SLAVE "fsi.slave"
+OBJECT_DECLARE_SIMPLE_TYPE(FSISlaveState, FSI_SLAVE)
+
+#define FSI_SLAVE_CONTROL_NR_REGS ((0x40 >> 2) + 1)
+
+typedef struct FSISlaveState {
+    DeviceState parent;
+
+    MemoryRegion iomem;
+    uint32_t regs[FSI_SLAVE_CONTROL_NR_REGS];
+} FSISlaveState;
+
 #endif /* FSI_FSI_H */