[RFC PATCH 15/25] acpi/pxb/cxl: Reserve host bridge MMIO

[Ben Widawsky]

For all host bridges, reserve MMIO space with _CRS. The MMIO for the
host bridge lives in a magically hard coded space in the system's
physical address space. The standard mechanism to tell the OS about
regions which can't be used for host bridges is _CRS.

Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
---
 hw/i386/acpi-build.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index aaed7da7dc..fae4fa28e1 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -28,6 +28,7 @@
 #include "qemu/bitmap.h"
 #include "qemu/error-report.h"
 #include "hw/pci/pci.h"
+#include "hw/cxl/cxl.h"
 #include "hw/core/cpu.h"
 #include "target/i386/cpu.h"
 #include "hw/misc/pvpanic.h"
@@ -1486,7 +1487,7 @@ static void build_smb0(Aml *table, I2CBus *smbus, int 
devnr, int func)
     aml_append(table, scope);
 }
 
-enum { PCI, PCIE };
+enum { PCI, PCIE, CXL };
 static void init_pci_acpi(Aml *dev, int uid, int type)
 {
     if (type == PCI) {
@@ -1635,20 +1636,28 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
             uint8_t bus_num = pci_bus_num(bus);
             uint8_t numa_node = pci_bus_numa_node(bus);
             int32_t uid = pci_bus_uid(bus);
+            int type;
 
             /* look only for expander root buses */
             if (!pci_bus_is_root(bus)) {
                 continue;
             }
 
+            type = pci_bus_is_cxl(bus) ? CXL :
+                                         pci_bus_is_express(bus) ? PCIE : PCI;
+
             if (bus_num < root_bus_limit) {
                 root_bus_limit = bus_num - 1;
             }
 
             scope = aml_scope("\\_SB");
-            dev = aml_device("PC%.02X", bus_num);
+            if (type == CXL) {
+                dev = aml_device("CXL%.01X", pci_bus_uid(bus));
+            } else {
+                dev = aml_device("PC%.02X", bus_num);
+            }
             aml_append(dev, aml_name_decl("_BBN", aml_int(bus_num)));
-            init_pci_acpi(dev, uid, pci_bus_is_express(bus) ? PCIE : PCI);
+            init_pci_acpi(dev, uid, type);
 
             if (numa_node != NUMA_NODE_UNASSIGNED) {
                 aml_append(dev, aml_name_decl("_PXM", aml_int(numa_node)));
@@ -1659,6 +1668,13 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
             aml_append(dev, aml_name_decl("_CRS", crs));
             aml_append(scope, dev);
             aml_append(dsdt, scope);
+
+            /* Handle the ranges for the PXB expanders */
+            if (type == CXL) {
+                uint64_t base = CXL_HOST_BASE + uid * 0x10000;
+                crs_range_insert(crs_range_set.mem_ranges, base,
+                                 base + 0x10000 - 1);
+            }
         }
     }
 
-- 
2.29.2