From 6a2897bb5f28944997a0c8410b6d2ee162b9ae98 Mon Sep 17 00:00:00 2001
From: Ninad Palsule <ninad@linux.ibm.com>
Date: Fri, 26 Jan 2024 04:49:49 -0600
Subject: hw/fsi: Introduce IBM's fsi-slave model
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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>
---
 hw/fsi/fsi.c        | 84 +++++++++++++++++++++++++++++++++++++++++++++++++++--
 hw/fsi/trace-events |  2 ++
 2 files changed, 84 insertions(+), 2 deletions(-)

(limited to 'hw')

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
-- 
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