Re: [Qemu-devel] [PATCH v2 2/2] hw/arm/virt-acpi-build: Add DBG2 table

[Andrew Jones]

On Sun, Sep 13, 2015 at 04:06:33PM +0100, Leif Lindholm wrote:
> Add a DBG2 table, describing the pl011 UART.
> 
> Signed-off-by: Leif Lindholm <address@hidden>
> ---
>  hw/arm/virt-acpi-build.c | 60 
> +++++++++++++++++++++++++++++++++++++++++++++++-
>  1 file changed, 59 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 9088248..0ea7023 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -352,6 +352,61 @@ build_rsdp(GArray *rsdp_table, GArray *linker, unsigned 
> rsdt)
>  }
>  
>  static void
> +build_dbg2(GArray *table_data, GArray *linker, VirtGuestInfo *guest_info)
> +{
> +    AcpiDebugPort2Header *dbg2;
> +    AcpiDebugPort2Device *dev;
> +    struct AcpiGenericAddress *addr;
> +    uint32_t *addr_size;
> +    char *name;
> +    const MemMapEntry *uart_memmap = &guest_info->memmap[VIRT_UART];
> +    int table_size, dev_size, namepath_length;
> +    const char namepath[] = ".";
> +
> +    namepath_length = strlen(namepath) + 1;
> +    dev_size = sizeof(*dev) + sizeof(*addr) * 1 + sizeof(uint32_t) * 1 +
> +        namepath_length;
> +    table_size = dev_size + sizeof(AcpiDebugPort2Header);
> +
> +    dbg2 = acpi_data_push(table_data, table_size);
> +    dev = (void *)dbg2 + sizeof(*dbg2);
> +    addr = (void *)dev + sizeof(*dev);
> +    addr_size = (void *)addr + sizeof(*addr);
> +    name = (void *)addr_size + sizeof(*addr_size);
> +
> +    dbg2->devices_offset = sizeof(*dbg2);
> +    dbg2->devices_count = 1;
> +
> +    /* First (only) debug device */
> +    dev->revision = 0;
> +    dev->length = cpu_to_le16(dev_size);
> +    dev->address_count = 1;
> +    dev->namepath_length = cpu_to_le16(namepath_length);
> +    dev->namepath_offset = cpu_to_le16((void *)name - (void *)dev);
> +    dev->oem_data_length = 0;
> +    dev->oem_data_offset = 0;
> +    dev->port_type = cpu_to_le16(0x8000);    /* Serial */
> +    dev->port_subtype = cpu_to_le16(0x3);    /* ARM PL011 UART */
> +    dev->base_address_offset = cpu_to_le16((void *)addr - (void *)dev);
> +    dev->address_size_offset = cpu_to_le16((void *)addr_size - (void *)dev);
> +
> +    /* First (only) address */
> +    addr->space_id = AML_SYSTEM_MEMORY;
> +    addr->bit_width = 8;
> +    addr->bit_offset = 0;
> +    addr->access_width = 1;
> +    addr->address = cpu_to_le64(uart_memmap->base);
> +
> +    /* Size of first (only) address */
> +    *addr_size = cpu_to_le32(sizeof(*addr));
> +
> +    /* Namespace String for first (only) device */
> +    strcpy(name, namepath);
> +
> +    build_header(linker, table_data, (void *)dbg2, "DBG2", table_size, 0);
> +}
> +
> +static void
>  build_spcr(GArray *table_data, GArray *linker, VirtGuestInfo *guest_info)
>  {
>      AcpiSerialPortConsoleRedirection *spcr;
> @@ -577,7 +632,7 @@ void virt_acpi_build(VirtGuestInfo *guest_info, 
> AcpiBuildTables *tables)
>      dsdt = tables_blob->len;
>      build_dsdt(tables_blob, tables->linker, guest_info);
>  
> -    /* FADT MADT GTDT MCFG SPCR pointed to by RSDT */
> +    /* FADT MADT GTDT MCFG DBG2 SPCR pointed to by RSDT */
>      acpi_add_table(table_offsets, tables_blob);
>      build_fadt(tables_blob, tables->linker, dsdt);
>  
> @@ -591,6 +646,9 @@ void virt_acpi_build(VirtGuestInfo *guest_info, 
> AcpiBuildTables *tables)
>      build_mcfg(tables_blob, tables->linker, guest_info);
>  
>      acpi_add_table(table_offsets, tables_blob);
> +    build_dbg2(tables_blob, tables->linker, guest_info);
> +
> +    acpi_add_table(table_offsets, tables_blob);
>      build_spcr(tables_blob, tables->linker, guest_info);
>  
>      /* RSDT is pointed to by RSDP */
> -- 
> 2.1.4
> 
> 

This looks good to me, since it's pretty unlikely we'll ever want
more than one device, so

Reviewed-by: Andrew Jones <address@hidden>

But, when I read that the table generation had become dynamic, I was sort
of expecting something like

void dbg2_add_device(...)
{
...
}

void build_dbg2(...)
{
   do_top_level_table_stuff...

   for_each_debug_device
      dbg2_add_device()

   finalize_table...
}

drew