[PATCH RFC 4/5] hw/cxl/accel: Add Back-Invalidate decoder capbility structure

[Ira Weiny <ira.weiny@intel.com>]

The presence of the Back-Invalidate (BI) decoder capability structure
indicates a CXL downstream port, root port, or device supports the BI
messages.

Add the BI capability structure to the accelerator device.

Not-Yet-Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 hw/cxl/cxl-component-utils.c   |  5 +++++
 hw/mem/cxl_type3.c             | 11 +++++++++++
 include/hw/cxl/cxl_component.h | 11 +++++++++--
 3 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/hw/cxl/cxl-component-utils.c b/hw/cxl/cxl-component-utils.c
index 7949d12b7351..a9efa252b4ae 100644
--- a/hw/cxl/cxl-component-utils.c
+++ b/hw/cxl/cxl-component-utils.c
@@ -228,6 +228,7 @@ void cxl_component_register_init_common(uint32_t *reg_state, uint32_t *write_msk
         init_cap_reg(EXTSEC, 6, 1);
         init_cap_reg(SNOOP, 8, 1);
         /* FALL THROUGH */
+    case CXL3_TYPE2_DEVICE:
     case CXL2_UPSTREAM_PORT:
     case CXL2_TYPE3_DEVICE:
     case CXL2_LOGICAL_DEVICE:
@@ -246,6 +247,10 @@ void cxl_component_register_init_common(uint32_t *reg_state, uint32_t *write_msk
         abort();
     }
 
+    if (type == CXL3_TYPE2_DEVICE) {
+        init_cap_reg(BI_DECODER, 12, 1);
+    }
+
     ARRAY_FIELD_DP32(reg_state, CXL_CAPABILITY_HEADER, ARRAY_SIZE, caps);
 #undef init_cap_reg
 }
diff --git a/hw/mem/cxl_type3.c b/hw/mem/cxl_type3.c
index c7eafd76d1ea..95fdaaa18f37 100644
--- a/hw/mem/cxl_type3.c
+++ b/hw/mem/cxl_type3.c
@@ -1692,6 +1692,16 @@ static void ct3d_registers(void)
 
 type_init(ct3d_registers);
 
+static void accel_reset(DeviceState *dev)
+{
+    CXLAccelDev *acceld = CXL_ACCEL(dev);
+    uint32_t *reg_state = acceld->parent_obj.cxl_cstate.crb.cache_mem_registers;
+    uint32_t *write_msk = acceld->parent_obj.cxl_cstate.crb.cache_mem_regs_write_mask;
+
+    cxl_component_register_init_common(reg_state, write_msk, CXL3_TYPE2_DEVICE);
+    cxl_device_register_init_common(&acceld->parent_obj.cxl_dstate);
+}
+
 static void cxl_accel_class_init(ObjectClass *oc, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(oc);
@@ -1703,6 +1713,7 @@ static void cxl_accel_class_init(ObjectClass *oc, void *data)
     pc->revision = 1;
 
     dc->desc = "CXL Accelerator Device (Type 2)";
+    dc->reset = accel_reset;
 }
 
 static const TypeInfo cxl_accel_dev_info = {
diff --git a/include/hw/cxl/cxl_component.h b/include/hw/cxl/cxl_component.h
index 7c08c02c5e9d..a5b5512aed94 100644
--- a/include/hw/cxl/cxl_component.h
+++ b/include/hw/cxl/cxl_component.h
@@ -28,6 +28,7 @@ enum reg_type {
     CXL2_UPSTREAM_PORT,
     CXL2_DOWNSTREAM_PORT,
     CXL3_SWITCH_MAILBOX_CCI,
+    CXL3_TYPE2_DEVICE,
 };
 
 /*
@@ -66,6 +67,7 @@ CXLx_CAPABILITY_HEADER(LINK, 2)
 CXLx_CAPABILITY_HEADER(HDM, 3)
 CXLx_CAPABILITY_HEADER(EXTSEC, 4)
 CXLx_CAPABILITY_HEADER(SNOOP, 5)
+CXLx_CAPABILITY_HEADER(BI_DECODER, 6)
 
 /*
  * Capability structures contain the actual registers that the CXL component
@@ -185,9 +187,14 @@ HDM_DECODER_INIT(3);
     (CXL_IDE_REGISTERS_OFFSET + CXL_IDE_REGISTERS_SIZE)
 #define CXL_SNOOP_REGISTERS_SIZE   0x8
 
+/* CXL 3.0 8.2.4.26 - CXL BI Decoder Capability Structure */
+#define CXL_BI_DECODER_REGISTERS_OFFSET \
+    (CXL_SNOOP_REGISTERS_OFFSET + CXL_SNOOP_REGISTERS_SIZE)
+#define CXL_BI_DECODER_REGISTERS_SIZE   0xC
+
 /* CXL 3.0 8.2.3 Table 8-21 */
-QEMU_BUILD_BUG_MSG((CXL_SNOOP_REGISTERS_OFFSET +
-                    CXL_SNOOP_REGISTERS_SIZE) >= CXL2_COMPONENT_CM_REGION_SIZE,
+QEMU_BUILD_BUG_MSG((CXL_BI_DECODER_REGISTERS_OFFSET +
+                    CXL_BI_DECODER_REGISTERS_SIZE) >= CXL2_COMPONENT_CM_REGION_SIZE,
                    "No space for registers");
 
 typedef struct component_registers {

-- 
2.40.0