hw/acpi: Upgrade ACPI SPCR table to support SPCR table revision 4 format

Update the SPCR table to accommodate the SPCR Table revision 4 [1].
The SPCR table has been modified to adhere to the revision 4 format [2].

[1]: https://learn.microsoft.com/en-us/windows-hardware/drivers/serports/serial-port-console-redirection-table
[2]: https://github.com/acpica/acpica/pull/931

Signed-off-by: Sia Jee Heng <jeeheng.sia@starfivetech.com>
Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Bibo Mao <maobibo@loongson.cn>
Message-ID: <20241028015744.624943-3-jeeheng.sia@starfivetech.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

6 files changed, 42 insertions, 13 deletions

diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
index 72282b1..e4d58d7 100644
--- a/hw/acpi/aml-build.c
+++ b/hw/acpi/aml-build.c
@@ -2078,7 +2078,7 @@ static void build_processor_hierarchy_node(GArray *tbl, uint32_t flags,
 
 void build_spcr(GArray *table_data, BIOSLinker *linker,
                 const AcpiSpcrData *f, const uint8_t rev,
-                const char *oem_id, const char *oem_table_id)
+                const char *oem_id, const char *oem_table_id, const char *name)
 {
     AcpiTable table = { .sig = "SPCR", .rev = rev, .oem_id = oem_id,
                         .oem_table_id = oem_table_id };
@@ -2124,9 +2124,21 @@ void build_spcr(GArray *table_data, BIOSLinker *linker,
     build_append_int_noprefix(table_data, f->pci_flags, 4);
     /* PCI Segment */
     build_append_int_noprefix(table_data, f->pci_segment, 1);
-    /* Reserved */
-    build_append_int_noprefix(table_data, 0, 4);
-
+    if (rev < 4) {
+        /* Reserved */
+        build_append_int_noprefix(table_data, 0, 4);
+    } else {
+        /* UartClkFreq */
+        build_append_int_noprefix(table_data, f->uart_clk_freq, 4);
+        /* PreciseBaudrate */
+        build_append_int_noprefix(table_data, f->precise_baudrate, 4);
+        /* NameSpaceStringLength */
+        build_append_int_noprefix(table_data, f->namespace_string_length, 2);
+        /* NameSpaceStringOffset */
+        build_append_int_noprefix(table_data, f->namespace_string_offset, 2);
+        /* NamespaceString[] */
+        g_array_append_vals(table_data, name, f->namespace_string_length);
+    }
     acpi_table_end(linker, &table);
 }
 /*
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 620992c..e92d3bd 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -463,8 +463,12 @@ spcr_setup(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
         .pci_flags = 0,
         .pci_segment = 0,
     };
-
-    build_spcr(table_data, linker, &serial, 2, vms->oem_id, vms->oem_table_id);
+    /*
+     * Passing NULL as the SPCR Table for Revision 2 doesn't support
+     * NameSpaceString.
+     */
+    build_spcr(table_data, linker, &serial, 2, vms->oem_id, vms->oem_table_id,
+               NULL);
 }
 
 /*
diff --git a/hw/loongarch/acpi-build.c b/hw/loongarch/acpi-build.c
index 50709bd..4e04f7b 100644
--- a/hw/loongarch/acpi-build.c
+++ b/hw/loongarch/acpi-build.c
@@ -276,8 +276,12 @@ spcr_setup(GArray *table_data, BIOSLinker *linker, MachineState *machine)
     };
 
     lvms = LOONGARCH_VIRT_MACHINE(machine);
+    /*
+     * Passing NULL as the SPCR Table for Revision 2 doesn't support
+     * NameSpaceString.
+     */
     build_spcr(table_data, linker, &serial, 2, lvms->oem_id,
-               lvms->oem_table_id);
+               lvms->oem_table_id, NULL);
 }
 
 typedef
diff --git a/hw/riscv/virt-acpi-build.c b/hw/riscv/virt-acpi-build.c
index 36d6a3a..68ef15a 100644
--- a/hw/riscv/virt-acpi-build.c
+++ b/hw/riscv/virt-acpi-build.c
@@ -200,14 +200,15 @@ acpi_dsdt_add_uart(Aml *scope, const MemMapEntry *uart_memmap,
 
 /*
  * Serial Port Console Redirection Table (SPCR)
- * Rev: 1.07
+ * Rev: 1.10
  */
 
 static void
 spcr_setup(GArray *table_data, BIOSLinker *linker, RISCVVirtState *s)
 {
+    const char name[] = ".";
     AcpiSpcrData serial = {
-        .interface_type = 0,       /* 16550 compatible */
+        .interface_type = 0x12,       /* 16550 compatible */
         .base_addr.id = AML_AS_SYSTEM_MEMORY,
         .base_addr.width = 32,
         .base_addr.offset = 0,
@@ -229,9 +230,14 @@ spcr_setup(GArray *table_data, BIOSLinker *linker, RISCVVirtState *s)
         .pci_function = 0,
         .pci_flags = 0,
         .pci_segment = 0,
+        .uart_clk_freq = 0,
+        .precise_baudrate = 0,
+        .namespace_string_length = sizeof(name),
+        .namespace_string_offset = 88,
     };
 
-    build_spcr(table_data, linker, &serial, 2, s->oem_id, s->oem_table_id);
+    build_spcr(table_data, linker, &serial, 4, s->oem_id, s->oem_table_id,
+               name);
 }
 
 /* RHCT Node[N] starts at offset 56 */
diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
index 0e6e82b..2e6e341 100644
--- a/include/hw/acpi/acpi-defs.h
+++ b/include/hw/acpi/acpi-defs.h
@@ -112,7 +112,6 @@ typedef struct AcpiSpcrData {
     uint8_t flow_control;
     uint8_t terminal_type;
     uint8_t language;
-    uint8_t reserved1;
     uint16_t pci_device_id;    /* Must be 0xffff if not PCI device */
     uint16_t pci_vendor_id;    /* Must be 0xffff if not PCI device */
     uint8_t pci_bus;
@@ -120,7 +119,11 @@ typedef struct AcpiSpcrData {
     uint8_t pci_function;
     uint32_t pci_flags;
     uint8_t pci_segment;
-    uint32_t reserved2;
+    uint32_t uart_clk_freq;
+    uint32_t precise_baudrate;
+    uint32_t namespace_string_length;
+    uint32_t namespace_string_offset;
+    char namespace_string[];
 } AcpiSpcrData;
 
 #define ACPI_FADT_ARM_PSCI_COMPLIANT  (1 << 0)
diff --git a/include/hw/acpi/aml-build.h b/include/hw/acpi/aml-build.h
index 4fd5da4..c18f681 100644
--- a/include/hw/acpi/aml-build.h
+++ b/include/hw/acpi/aml-build.h
@@ -507,5 +507,5 @@ void build_tpm2(GArray *table_data, BIOSLinker *linker, GArray *tcpalog,
 
 void build_spcr(GArray *table_data, BIOSLinker *linker,
                 const AcpiSpcrData *f, const uint8_t rev,
-                const char *oem_id, const char *oem_table_id);
+                const char *oem_id, const char *oem_table_id, const char *name);
 #endif