hw/cxl: Add a switch mailbox CCI function

CXL switch CCIs were added in CXL r3.0. They are a PCI function,
identified by class code that provides a CXL mailbox (identical
to that previously defined for CXL type 3 memory devices) over which
various FM-API commands may be used. Whilst the intent of this
feature is enable switch control from a BMC attached to a switch
upstream port, it is also useful to allow emulation of this feature
on the upstream port connected to a host using the CXL devices as
this greatly simplifies testing.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Message-Id: <20231023160806.13206-7-Jonathan.Cameron@huawei.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/hw/cxl/cxl-device-utils.c b/hw/cxl/cxl-device-utils.c
index eb86634250..f8938678c7 100644
--- a/hw/cxl/cxl-device-utils.c
+++ b/hw/cxl/cxl-device-utils.c
@@ -67,6 +67,9 @@ static uint64_t mailbox_reg_read(void *opaque, hwaddr offset, unsigned size)
 
     if (object_dynamic_cast(OBJECT(cci->intf), TYPE_CXL_TYPE3)) {
         cxl_dstate = &CXL_TYPE3(cci->intf)->cxl_dstate;
+    } else if (object_dynamic_cast(OBJECT(cci->intf),
+                                   TYPE_CXL_SWITCH_MAILBOX_CCI)) {
+        cxl_dstate = &CXL_SWITCH_MAILBOX_CCI(cci->intf)->cxl_dstate;
     } else {
         return 0;
     }
@@ -135,6 +138,9 @@ static void mailbox_reg_write(void *opaque, hwaddr offset, uint64_t value,
 
     if (object_dynamic_cast(OBJECT(cci->intf), TYPE_CXL_TYPE3)) {
         cxl_dstate = &CXL_TYPE3(cci->intf)->cxl_dstate;
+    } else if (object_dynamic_cast(OBJECT(cci->intf),
+                                   TYPE_CXL_SWITCH_MAILBOX_CCI)) {
+        cxl_dstate = &CXL_SWITCH_MAILBOX_CCI(cci->intf)->cxl_dstate;
     } else {
         return;
     }
@@ -365,6 +371,27 @@ void cxl_device_register_init_t3(CXLType3Dev *ct3d)
                               CXL_MAILBOX_MAX_PAYLOAD_SIZE);
 }
 
+void cxl_device_register_init_swcci(CSWMBCCIDev *sw)
+{
+    CXLDeviceState *cxl_dstate = &sw->cxl_dstate;
+    uint64_t *cap_h = cxl_dstate->caps_reg_state64;
+    const int cap_count = 3;
+
+    /* CXL Device Capabilities Array Register */
+    ARRAY_FIELD_DP64(cap_h, CXL_DEV_CAP_ARRAY, CAP_ID, 0);
+    ARRAY_FIELD_DP64(cap_h, CXL_DEV_CAP_ARRAY, CAP_VERSION, 1);
+    ARRAY_FIELD_DP64(cap_h, CXL_DEV_CAP_ARRAY, CAP_COUNT, cap_count);
+
+    cxl_device_cap_init(cxl_dstate, DEVICE_STATUS, 1, 2);
+    device_reg_init_common(cxl_dstate);
+
+    cxl_device_cap_init(cxl_dstate, MAILBOX, 2, 1);
+    mailbox_reg_init_common(cxl_dstate);
+
+    cxl_device_cap_init(cxl_dstate, MEMORY_DEVICE, 0x4000, 1);
+    memdev_reg_init_common(cxl_dstate);
+}
+
 uint64_t cxl_device_get_timestamp(CXLDeviceState *cxl_dstate)
 {
     uint64_t time, delta;