[Qemu-devel] [RFC PATCH 1/3] hw/arm/virt-acpi-build: use acpi_get_mcfg() to calculate bus number

[Wei Yang <richardw.yang@linux.intel.com>]

To build MCFG, two information is necessary:

    * bus number
    * base address

Abstract these two information to AcpiMcfgInfo so that build_mcfg and
build_mcfg_q35 will have the same declaration.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
---
 hw/arm/virt-acpi-build.c    | 28 ++++++++++++++++++++--------
 hw/i386/acpi-build.c        |  5 -----
 include/hw/acpi/aml-build.h |  5 +++++
 3 files changed, 25 insertions(+), 13 deletions(-)

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 57679a89bf..7713c2d809 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -545,23 +545,32 @@ build_srat(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
                  "SRAT", table_data->len - srat_start, 3, NULL, NULL);
 }
 
-static void
-build_mcfg(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
+static bool acpi_get_mcfg(AcpiMcfgInfo *mcfg)
 {
-    AcpiTableMcfg *mcfg;
+    VirtMachineState *vms = VIRT_MACHINE(qdev_get_machine());
     const MemMapEntry *memmap = vms->memmap;
     int ecam_id = VIRT_ECAM_ID(vms->highmem_ecam);
+
+    mcfg->mcfg_base = memmap[ecam_id].base;
+    mcfg->mcfg_size = memmap[ecam_id].size;
+
+    return true;
+}
+
+static void
+build_mcfg(GArray *table_data, BIOSLinker *linker, AcpiMcfgInfo *info)
+{
+    AcpiTableMcfg *mcfg;
     int len = sizeof(*mcfg) + sizeof(mcfg->allocation[0]);
     int mcfg_start = table_data->len;
 
     mcfg = acpi_data_push(table_data, len);
-    mcfg->allocation[0].address = cpu_to_le64(memmap[ecam_id].base);
+    mcfg->allocation[0].address = cpu_to_le64(info->mcfg_base);
 
     /* Only a single allocation so no need to play with segments */
     mcfg->allocation[0].pci_segment = cpu_to_le16(0);
     mcfg->allocation[0].start_bus_number = 0;
-    mcfg->allocation[0].end_bus_number =
-        PCIE_MMCFG_BUS(memmap[ecam_id].size - 1);
+    mcfg->allocation[0].end_bus_number = PCIE_MMCFG_BUS(info->mcfg_size - 1);
 
     build_header(linker, table_data, (void *)(table_data->data + mcfg_start),
                  "MCFG", table_data->len - mcfg_start, 1, NULL, NULL);
@@ -779,6 +788,7 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
     VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
     GArray *table_offsets;
     unsigned dsdt, xsdt;
+    AcpiMcfgInfo mcfg;
     GArray *tables_blob = tables->table_data;
 
     table_offsets = g_array_new(false, true /* clear */,
@@ -802,8 +812,10 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
     acpi_add_table(table_offsets, tables_blob);
     build_gtdt(tables_blob, tables->linker, vms);
 
-    acpi_add_table(table_offsets, tables_blob);
-    build_mcfg(tables_blob, tables->linker, vms);
+    if (acpi_get_mcfg(&mcfg)) {
+        acpi_add_table(table_offsets, tables_blob);
+        build_mcfg(tables_blob, tables->linker, &mcfg);
+    }
 
     acpi_add_table(table_offsets, tables_blob);
     build_spcr(tables_blob, tables->linker, vms);
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index 9ecc96dcc7..c5b1c3be99 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -86,11 +86,6 @@
 /* Default IOAPIC ID */
 #define ACPI_BUILD_IOAPIC_ID 0x0
 
-typedef struct AcpiMcfgInfo {
-    uint64_t mcfg_base;
-    uint32_t mcfg_size;
-} AcpiMcfgInfo;
-
 typedef struct AcpiPmInfo {
     bool s3_disabled;
     bool s4_disabled;
diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
index 1a563ad756..b63b85d67c 100644
--- a/include/hw/acpi/aml-build.h
+++ b/include/hw/acpi/aml-build.h
@@ -223,6 +223,11 @@ struct AcpiBuildTables {
     BIOSLinker *linker;
 } AcpiBuildTables;
 
+typedef struct AcpiMcfgInfo {
+    uint64_t mcfg_base;
+    uint32_t mcfg_size;
+} AcpiMcfgInfo;
+
 /**
  * init_aml_allocator:
  *
-- 
2.19.1