[RFC PATCH 20/25] acpi/cxl: Add _OSC implementation (9.14.2)

[Ben Widawsky <ben.widawsky@intel.com>]

CXL 2.0 specification adds 2 new dwords to the existing _OSC definition
from PCIe. The new dwords are accessed with a new uuid. This
implementation supports what is in the specification.

We are currently in the process of trying to define a new definition for
_OSC. See later work for an explanation.

Signed-off-by: Ben Widawsky <ben.widawsky@intel.com>
---
 hw/acpi/Kconfig       |   5 ++
 hw/acpi/cxl.c         | 104 ++++++++++++++++++++++++++++++++++++++++++
 hw/acpi/meson.build   |   1 +
 hw/i386/acpi-build.c  |  12 ++++-
 include/hw/acpi/cxl.h |  23 ++++++++++
 5 files changed, 144 insertions(+), 1 deletion(-)
 create mode 100644 hw/acpi/cxl.c
 create mode 100644 include/hw/acpi/cxl.h

diff --git a/hw/acpi/Kconfig b/hw/acpi/Kconfig
index 1932f66af8..b27907953e 100644
--- a/hw/acpi/Kconfig
+++ b/hw/acpi/Kconfig
@@ -5,6 +5,7 @@ config ACPI_X86
     bool
     select ACPI
     select ACPI_NVDIMM
+    select ACPI_CXL
     select ACPI_CPU_HOTPLUG
     select ACPI_MEMORY_HOTPLUG
     select ACPI_HMAT
@@ -42,3 +43,7 @@ config ACPI_VMGENID
     depends on PC
 
 config ACPI_HW_REDUCED
+
+config ACPI_CXL
+    bool
+    depends on ACPI
diff --git a/hw/acpi/cxl.c b/hw/acpi/cxl.c
new file mode 100644
index 0000000000..7124d5a1a3
--- /dev/null
+++ b/hw/acpi/cxl.c
@@ -0,0 +1,104 @@
+/*
+ * CXL ACPI Implementation
+ *
+ * Copyright(C) 2020 Intel Corporation.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>
+ */
+
+#include "qemu/osdep.h"
+#include "hw/cxl/cxl.h"
+#include "hw/acpi/acpi.h"
+#include "hw/acpi/aml-build.h"
+#include "hw/acpi/bios-linker-loader.h"
+#include "hw/acpi/cxl.h"
+#include "qapi/error.h"
+#include "qemu/uuid.h"
+
+static Aml *__build_cxl_osc_method(void)
+{
+    Aml *method, *if_uuid, *else_uuid, *if_arg1_not_1, *if_cxl, *if_caps_masked;
+    Aml *a_ctrl = aml_local(0);
+    Aml *a_cdw1 = aml_name("CDW1");
+
+    method = aml_method("_OSC", 4, AML_NOTSERIALIZED);
+    aml_append(method, aml_create_dword_field(aml_arg(3), aml_int(0), "CDW1"));
+
+    /* 9.14.2.1.4 */
+    if_uuid = aml_if(
+        aml_lor(aml_equal(aml_arg(0),
+                          aml_touuid("33DB4D5B-1FF7-401C-9657-7441C03DD766")),
+                aml_equal(aml_arg(0),
+                          aml_touuid("68F2D50B-C469-4D8A-BD3D-941A103FD3FC"))));
+    aml_append(if_uuid, aml_create_dword_field(aml_arg(3), aml_int(4), "CDW2"));
+    aml_append(if_uuid, aml_create_dword_field(aml_arg(3), aml_int(8), "CDW3"));
+
+    aml_append(if_uuid, aml_store(aml_name("CDW3"), a_ctrl));
+
+    /* This is all the same as what's used for PCIe */
+    aml_append(if_uuid,
+               aml_and(aml_name("CTRL"), aml_int(0x1F), aml_name("CTRL")));
+
+    if_arg1_not_1 = aml_if(aml_lnot(aml_equal(aml_arg(1), aml_int(0x1))));
+    /* Unknown revision */
+    aml_append(if_arg1_not_1, aml_or(a_cdw1, aml_int(0x08), a_cdw1));
+    aml_append(if_uuid, if_arg1_not_1);
+
+    if_caps_masked = aml_if(aml_lnot(aml_equal(aml_name("CDW3"), a_ctrl)));
+    /* Capability bits were masked */
+    aml_append(if_caps_masked, aml_or(a_cdw1, aml_int(0x10), a_cdw1));
+    aml_append(if_uuid, if_caps_masked);
+
+    aml_append(if_uuid, aml_store(aml_name("CDW2"), aml_name("SUPP")));
+    aml_append(if_uuid, aml_store(aml_name("CDW3"), aml_name("CTRL")));
+
+    if_cxl = aml_if(aml_equal(
+        aml_arg(0), aml_touuid("68F2D50B-C469-4D8A-BD3D-941A103FD3FC")));
+    /* CXL support field */
+    aml_append(if_cxl, aml_create_dword_field(aml_arg(3), aml_int(12), "CDW4"));
+    /* CXL capabilities */
+    aml_append(if_cxl, aml_create_dword_field(aml_arg(3), aml_int(16), "CDW5"));
+    aml_append(if_cxl, aml_store(aml_name("CDW4"), aml_name("SUPC")));
+    aml_append(if_cxl, aml_store(aml_name("CDW5"), aml_name("CTRC")));
+
+    /* CXL 2.0 Port/Device Register access */
+    aml_append(if_cxl,
+               aml_or(aml_name("CDW5"), aml_int(0x1), aml_name("CDW5")));
+    aml_append(if_uuid, if_cxl);
+
+    /* Update DWORD3 (the return value) */
+    aml_append(if_uuid, aml_store(a_ctrl, aml_name("CDW3")));
+
+    aml_append(if_uuid, aml_return(aml_arg(3)));
+    aml_append(method, if_uuid);
+
+    else_uuid = aml_else();
+
+    /* unrecognized uuid */
+    aml_append(else_uuid,
+               aml_or(aml_name("CDW1"), aml_int(0x4), aml_name("CDW1")));
+    aml_append(else_uuid, aml_return(aml_arg(3)));
+    aml_append(method, else_uuid);
+
+    return method;
+}
+
+void build_cxl_osc_method(Aml *dev)
+{
+    aml_append(dev, aml_name_decl("SUPP", aml_int(0)));
+    aml_append(dev, aml_name_decl("CTRL", aml_int(0)));
+    aml_append(dev, aml_name_decl("SUPC", aml_int(0)));
+    aml_append(dev, aml_name_decl("CTRC", aml_int(0)));
+    aml_append(dev, __build_cxl_osc_method());
+}
diff --git a/hw/acpi/meson.build b/hw/acpi/meson.build
index dd69577212..9f5c5ced28 100644
--- a/hw/acpi/meson.build
+++ b/hw/acpi/meson.build
@@ -10,6 +10,7 @@ acpi_ss.add(when: 'CONFIG_ACPI_CPU_HOTPLUG', if_true: files('cpu_hotplug.c'))
 acpi_ss.add(when: 'CONFIG_ACPI_MEMORY_HOTPLUG', if_true: files('memory_hotplug.c'))
 acpi_ss.add(when: 'CONFIG_ACPI_NVDIMM', if_true: files('nvdimm.c'))
 acpi_ss.add(when: 'CONFIG_ACPI_PCI', if_true: files('pci.c'))
+acpi_ss.add(when: 'CONFIG_ACPI_CXL', if_true: files('cxl.c'))
 acpi_ss.add(when: 'CONFIG_ACPI_VMGENID', if_true: files('vmgenid.c'))
 acpi_ss.add(when: 'CONFIG_ACPI_HW_REDUCED', if_true: files('generic_event_device.c'))
 acpi_ss.add(when: 'CONFIG_ACPI_HMAT', if_true: files('hmat.c'))
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index fae4fa28e1..dd1f8b39d4 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -66,6 +66,7 @@
 #include "hw/acpi/aml-build.h"
 #include "hw/acpi/utils.h"
 #include "hw/acpi/pci.h"
+#include "hw/acpi/cxl.h"
 
 #include "qom/qom-qobject.h"
 #include "hw/i386/amd_iommu.h"
@@ -1493,11 +1494,20 @@ static void init_pci_acpi(Aml *dev, int uid, int type)
     if (type == PCI) {
         aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
         aml_append(dev, aml_name_decl("_UID", aml_int(uid)));
-    } else {
+    } else if (type == PCIE) {
         aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A08")));
         aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03")));
         aml_append(dev, aml_name_decl("_UID", aml_int(uid)));
         aml_append(dev, build_q35_osc_method());
+    } else /* CXL */ {
+        struct Aml *pkg = aml_package(2);
+
+        aml_append(dev, aml_name_decl("_HID", aml_string("ACPI0016")));
+        aml_append(pkg, aml_eisaid("PNP0A08"));
+        aml_append(pkg, aml_eisaid("PNP0A03"));
+        aml_append(dev, aml_name_decl("_CID", pkg));
+        aml_append(dev, aml_name_decl("_UID", aml_int(uid)));
+        build_cxl_osc_method(dev);
     }
 }
 
diff --git a/include/hw/acpi/cxl.h b/include/hw/acpi/cxl.h
new file mode 100644
index 0000000000..7b8f3b8a2e
--- /dev/null
+++ b/include/hw/acpi/cxl.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright (C) 2020 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef HW_ACPI_CXL_H
+#define HW_ACPI_CXL_H
+
+void build_cxl_osc_method(Aml *dev);
+
+#endif
-- 
2.29.2