Re: [Qemu-devel] [PATCH 4/8] hw: arm: Carry RSDP specific data through AcpiRsdpData

[Igor Mammedov <imammedo@redhat.com>]

On Mon, 26 Nov 2018 17:29:37 +0100
Samuel Ortiz <sameo@linux.intel.com> wrote:

> That will allow us to generalize the ARM build_rsdp() routine to support
> both legacy RSDP (The current i386 implementation) and extended RSDP
> (The ARM implementation).
> 
> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
> ---
>  include/hw/acpi/acpi-defs.h | 11 +++++++++++
>  hw/arm/virt-acpi-build.c    | 27 ++++++++++++++++++++++-----
>  2 files changed, 33 insertions(+), 5 deletions(-)
> 
> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
> index af8e023968..e7fd24c6c5 100644
> --- a/include/hw/acpi/acpi-defs.h
> +++ b/include/hw/acpi/acpi-defs.h
> @@ -53,6 +53,17 @@ struct AcpiRsdpDescriptor {        /* Root System Descriptor Pointer */
>  } QEMU_PACKED;
>  typedef struct AcpiRsdpDescriptor AcpiRsdpDescriptor;
>  
> +typedef struct AcpiRsdpData {
> +    uint8_t oem_id[6]; /* OEM identification */
> +    uint8_t revision;  /* Must be 0 for 1.0, 2 for 2.0 */
> +
> +    unsigned *rsdt_tbl_offset;
> +    unsigned *xsdt_tbl_offset;
> +} AcpiRsdpData;
> +

> +#define ACPI_RSDP_REV_1 0
> +#define ACPI_RSDP_REV_2 2
it's one time used spec defined values so just use values directly
in place with a comment, so reader won't have to jump around code
when comparing to spec.

> +
>  /* Table structure from Linux kernel (the ACPI tables are under the
>     BSD license) */
>  
> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
> index 0835900052..2dad465ecf 100644
> --- a/hw/arm/virt-acpi-build.c
> +++ b/hw/arm/virt-acpi-build.c
> @@ -368,7 +368,7 @@ static void acpi_dsdt_add_power_button(Aml *scope)
>  
>  /* RSDP */
>  static void
> -build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)
> +build_rsdp(GArray *rsdp_table, BIOSLinker *linker, AcpiRsdpData *rsdp_data)
>  {
>      AcpiRsdpDescriptor *rsdp = acpi_data_push(rsdp_table, sizeof *rsdp);
>      unsigned xsdt_pa_size = sizeof(rsdp->xsdt_physical_address);
> @@ -379,14 +379,14 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)
>                               true /* fseg memory */);
>  
>      memcpy(&rsdp->signature, "RSD PTR ", sizeof(rsdp->signature));
> -    memcpy(rsdp->oem_id, ACPI_BUILD_APPNAME6, sizeof(rsdp->oem_id));
> +    memcpy(rsdp->oem_id, rsdp_data->oem_id, sizeof(rsdp->oem_id));
>      rsdp->length = cpu_to_le32(sizeof(*rsdp));
> -    rsdp->revision = 0x02;
> +    rsdp->revision = rsdp_data->revision;
>  
>      /* Address to be filled by Guest linker */
>      bios_linker_loader_add_pointer(linker,
>          ACPI_BUILD_RSDP_FILE, xsdt_pa_offset, xsdt_pa_size,
> -        ACPI_BUILD_TABLE_FILE, xsdt_tbl_offset);
> +        ACPI_BUILD_TABLE_FILE, *rsdp_data->xsdt_tbl_offset);
>  
>      /* Checksum to be filled by Guest linker */
>      bios_linker_loader_add_checksum(linker, ACPI_BUILD_RSDP_FILE,
> @@ -399,6 +399,20 @@ build_rsdp(GArray *rsdp_table, BIOSLinker *linker, unsigned xsdt_tbl_offset)
>          (char *)&rsdp->extended_checksum - rsdp_table->data);
>  }
>  
> +static void
> +init_rsdp_data(AcpiRsdpData *data, const char *oem_id, uint8_t revision,
> +               unsigned *rsdt_offset, unsigned *xsdt_offset)
> +{
> +    /* Caller must provide an OEM ID */
> +    g_assert(oem_id);
> +    g_assert(strlen(oem_id) >= 6);
> +
> +    memcpy(data->oem_id, oem_id, 6);
> +    data->revision = revision;
> +    data->rsdt_tbl_offset = rsdt_offset;
> +    data->xsdt_tbl_offset = xsdt_offset;
> +}
> +
>  static void
>  build_iort(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>  {
> @@ -810,6 +824,7 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
>      GArray *table_offsets;
>      unsigned dsdt, xsdt;
>      GArray *tables_blob = tables->table_data;
> +    AcpiRsdpData rsdp;
s/rsdp/rsdp_info/

>  
>      table_offsets = g_array_new(false, true /* clear */,
>                                          sizeof(uint32_t));
> @@ -857,7 +872,9 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
>      build_xsdt(tables_blob, tables->linker, table_offsets, NULL, NULL);
>  
>      /* RSDP is in FSEG memory, so allocate it separately */
> -    build_rsdp(tables->rsdp, tables->linker, xsdt);
> +    init_rsdp_data(&rsdp, ACPI_BUILD_APPNAME6, ACPI_RSDP_REV_2,
> +                   NULL, &xsdt);
It would be more concise to use declarative style without extra clutter:

-    init_rsdp_data(&rsdp, ACPI_BUILD_APPNAME6, ACPI_RSDP_REV_2,
-                   NULL, &xsdt);
-    build_rsdp(tables->rsdp, tables->linker, &rsdp);
+    {
+       AcpiRsdpData rsdp = {
+           .revision = 2,
+           .oem_id = ACPI_BUILD_APPNAME6,
+           .xsdt_tbl_offset = &xsdt,
+           .rsdt_tbl_offset = NULL,
+       };
+       build_rsdp(tables->rsdp, tables->linker, &rsdp);
+    }

> +    build_rsdp(tables->rsdp, tables->linker, &rsdp);
>  
>      /* Cleanup memory that's no longer used. */
>      g_array_free(table_offsets, true);