Re: [PATCH RESEND v4 2/3] hw/acpi: Upgrade ACPI SPCR table to support SPCR table revision 4 format

[Sunil V L]

On Fri, Aug 23, 2024 at 04:31:41AM -0700, Sia Jee Heng wrote:
> 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>
> Acked-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  hw/acpi/aml-build.c         | 20 ++++++++++++++++----
>  hw/arm/virt-acpi-build.c    | 10 +++++++---
>  hw/riscv/virt-acpi-build.c  | 12 +++++++++---
>  include/hw/acpi/acpi-defs.h |  7 +++++--
>  include/hw/acpi/aml-build.h |  2 +-
>  5 files changed, 38 insertions(+), 13 deletions(-)
> 
> diff --git a/hw/acpi/aml-build.c b/hw/acpi/aml-build.c
> index 6d4517cfbe..ad0a306db1 100644
> --- a/hw/acpi/aml-build.c
> +++ b/hw/acpi/aml-build.c
> @@ -1996,7 +1996,7 @@ 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 };
> @@ -2042,9 +2042,21 @@ 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 f76fb117ad..cc27ba7daf 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -435,7 +435,7 @@ build_iort(GArray *table_data, BIOSLinker *linker, 
> VirtMachineState *vms)
>  
>  /*
>   * Serial Port Console Redirection Table (SPCR)
> - * Rev: 1.07
> + * Rev: 1.10
Why should this comment be updated? Since revision 2 of SPCR table ARM
uses corresponds to only 1.07 right?

>   */
>  static void
>  spcr_setup(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
> @@ -464,8 +464,12 @@ 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/riscv/virt-acpi-build.c b/hw/riscv/virt-acpi-build.c
> index 36d6a3a412..68ef15acac 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 0e6e82b339..2e6e341998 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 a3784155cb..68c0f2dbee 100644
> --- a/include/hw/acpi/aml-build.h
> +++ b/include/hw/acpi/aml-build.h
> @@ -500,5 +500,5 @@ 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

Otherwise, LGTM.

Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>