[RFC PATCH v3 18/31] acpi/pxb/cxl: Reserve host bridge MMIO

Ben Widawsky
2021-02-02T01:01:55Z

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 145a503e92..ecdc10b148 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"
@@ -1194,7 +1195,7 @@ 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) {
@@ -1344,20 +1345,28 @@ 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)));
@@ -1369,6 +1378,13 @@ 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);
+ }
}
}

--
2.30.0