[PATCH v6 4/8] hw/pci-bridge/cxl_root_port: Wire up MSI

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

Done to avoid fixing ACPI route description of traditional PCI interrupts on q35
and because we should probably move with the times anyway.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
---
 hw/pci-bridge/cxl_root_port.c | 61 +++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/hw/pci-bridge/cxl_root_port.c b/hw/pci-bridge/cxl_root_port.c
index 00195257f7..7dfd20aa67 100644
--- a/hw/pci-bridge/cxl_root_port.c
+++ b/hw/pci-bridge/cxl_root_port.c
@@ -22,6 +22,7 @@
 #include "qemu/range.h"
 #include "hw/pci/pci_bridge.h"
 #include "hw/pci/pcie_port.h"
+#include "hw/pci/msi.h"
 #include "hw/qdev-properties.h"
 #include "hw/sysbus.h"
 #include "qapi/error.h"
@@ -29,6 +30,10 @@
 
 #define CXL_ROOT_PORT_DID 0x7075
 
+#define CXL_RP_MSI_OFFSET               0x60
+#define CXL_RP_MSI_SUPPORTED_FLAGS      PCI_MSI_FLAGS_MASKBIT
+#define CXL_RP_MSI_NR_VECTOR            2
+
 /* Copied from the gen root port which we derive */
 #define GEN_PCIE_ROOT_PORT_AER_OFFSET 0x100
 #define GEN_PCIE_ROOT_PORT_ACS_OFFSET \
@@ -47,6 +52,49 @@ typedef struct CXLRootPort {
 #define TYPE_CXL_ROOT_PORT "cxl-rp"
 DECLARE_INSTANCE_CHECKER(CXLRootPort, CXL_ROOT_PORT, TYPE_CXL_ROOT_PORT)
 
+/*
+ * If two MSI vector are allocated, Advanced Error Interrupt Message Number
+ * is 1. otherwise 0.
+ * 17.12.5.10 RPERRSTS,  32:27 bit Advanced Error Interrupt Message Number.
+ */
+static uint8_t cxl_rp_aer_vector(const PCIDevice *d)
+{
+    switch (msi_nr_vectors_allocated(d)) {
+    case 1:
+        return 0;
+    case 2:
+        return 1;
+    case 4:
+    case 8:
+    case 16:
+    case 32:
+    default:
+        break;
+    }
+    abort();
+    return 0;
+}
+
+static int cxl_rp_interrupts_init(PCIDevice *d, Error **errp)
+{
+    int rc;
+
+    rc = msi_init(d, CXL_RP_MSI_OFFSET, CXL_RP_MSI_NR_VECTOR,
+                  CXL_RP_MSI_SUPPORTED_FLAGS & PCI_MSI_FLAGS_64BIT,
+                  CXL_RP_MSI_SUPPORTED_FLAGS & PCI_MSI_FLAGS_MASKBIT,
+                  errp);
+    if (rc < 0) {
+        assert(rc == -ENOTSUP);
+    }
+
+    return rc;
+}
+
+static void cxl_rp_interrupts_uninit(PCIDevice *d)
+{
+    msi_uninit(d);
+}
+
 static void latch_registers(CXLRootPort *crp)
 {
     uint32_t *reg_state = crp->cxl_cstate.crb.cache_mem_registers;
@@ -183,6 +231,15 @@ static void cxl_rp_dvsec_write_config(PCIDevice *dev, uint32_t addr,
     }
 }
 
+static void cxl_rp_aer_vector_update(PCIDevice *d)
+{
+    PCIERootPortClass *rpc = PCIE_ROOT_PORT_GET_CLASS(d);
+
+    if (rpc->aer_vector) {
+        pcie_aer_root_set_vector(d, rpc->aer_vector(d));
+    }
+}
+
 static void cxl_rp_write_config(PCIDevice *d, uint32_t address, uint32_t val,
                                 int len)
 {
@@ -192,6 +249,7 @@ static void cxl_rp_write_config(PCIDevice *d, uint32_t address, uint32_t val,
 
     pcie_cap_slot_get(d, &slt_ctl, &slt_sta);
     pci_bridge_write_config(d, address, val, len);
+    cxl_rp_aer_vector_update(d);
     pcie_cap_flr_write_config(d, address, val, len);
     pcie_cap_slot_write_config(d, slt_ctl, slt_sta, address, val, len);
     pcie_aer_write_config(d, address, val, len);
@@ -220,6 +278,9 @@ static void cxl_root_port_class_init(ObjectClass *oc, void *data)
 
     rpc->aer_offset = GEN_PCIE_ROOT_PORT_AER_OFFSET;
     rpc->acs_offset = GEN_PCIE_ROOT_PORT_ACS_OFFSET;
+    rpc->aer_vector = cxl_rp_aer_vector;
+    rpc->interrupts_init = cxl_rp_interrupts_init;
+    rpc->interrupts_uninit = cxl_rp_interrupts_uninit;
 
     dc->hotpluggable = false;
 }
-- 
2.37.2