Re: [PATCH for-6.2] hw/arm/virt_acpi_build: Generate DBG2 table

[Eric Auger]

Hi Igor,

On 8/10/21 2:20 PM, Igor Mammedov wrote:
> On Tue, 10 Aug 2021 14:05:40 +0200
> Eric Auger <eric.auger@redhat.com> wrote:
>
>> Hi Igor,
>>
>> On 8/10/21 12:52 PM, Igor Mammedov wrote:
>>> On Tue, 10 Aug 2021 10:30:57 +0200
>>> Eric Auger <eric.auger@redhat.com> wrote:
>>>  
>>>> ARM SBBR specification mandates DBG2 table (Debug Port Table 2).
>>>> this latter allows to describe one or more debug ports.
>>>>
>>>> Generate an DBG2 table featuring a single debug port, the PL011.
>>>>
>>>> The DBG2 specification can be found at:
>>>> https://docs.microsoft.com/en-us/windows-hardware/drivers/bringup/acpi-debug-port-table?redirectedfrom=MSDN
>>>>
>>>> Signed-off-by: Eric Auger <eric.auger@redhat.com>  
>>> using packed structures for composing ACPI tables is discouraged,
>>> pls use build_append_int_noprefix() API instead. You can look at
>>> build_amd_iommu() as an example.  
>> I understand this for new code outside of hw/arm/virt-acpi-build.c.
>> However build_append_int_noprefix() is not (yet) used in
>> virt-acpi-build.c so this would bring heterogeneity. So does it mean
>> that any new ACPI description introduced there should also adopt this
>> new style? Drew will suggest to migrate everything but well ;-)
>
> new style should be used for any new ACPI code.
> There is a series on list that converts old style to new style across tree
> (currently planned for merging into 6.2)
> https://www.mail-archive.com/qemu-devel@nongnu.org/msg822151.html
Ak OK I missed that refactoring. Now I better understand ;-)
> So I'm going to push back any new patches that use old style
> to reduce time on rewriting others code when it could be written
> using preferred style.
>
> PS:
> Perhaps you'd like to review ARM related patches.

Sure!

Thanks

Eric
>
>
>> Thanks
>>
>> Eric
>>> PS:
>>> Also note field comments format.
>>> /it should be verbatim copy of entry name from respective table in spec/
>>>  
>>>> ---
>>>>
>>>> Tested by comparing the content with the table generated
>>>> by EDK2 along with the SBSA-REF machine (code generated by
>>>> DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c).
>>>>
>>>> I reused the Generic Address Structure filled by QEMU in the SPCR, ie.
>>>> bit_width = 8 and byte access. While EDK2 sets bit_width = 32 and
>>>> dword access. Also the name exposed by acpica tools is different:
>>>> 'COM0' in my case where '\_SB.COM0' in SBSA-REF case?
>>>> ---
>>>>  hw/arm/virt-acpi-build.c    | 77 ++++++++++++++++++++++++++++++++++++-
>>>>  include/hw/acpi/acpi-defs.h | 50 ++++++++++++++++++++++++
>>>>  2 files changed, 126 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
>>>> index 037cc1fd82..35f27b41df 100644
>>>> --- a/hw/arm/virt-acpi-build.c
>>>> +++ b/hw/arm/virt-acpi-build.c
>>>> @@ -563,6 +563,78 @@ build_gtdt(GArray *table_data, BIOSLinker *linker, 
>>>> VirtMachineState *vms)
>>>>                   vms->oem_table_id);
>>>>  }
>>>>  
>>>> +#define ACPI_DBG2_PL011_UART_LENGTH 0x1000
>>>> +
>>>> +/* DBG2 */
>>>> +static void
>>>> +build_dbg2(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>>>> +{
>>>> +    int addr_offset, addrsize_offset, namespace_offset, namespace_length;
>>>> +    const MemMapEntry *uart_memmap = &vms->memmap[VIRT_UART];
>>>> +    struct AcpiGenericAddress *base_address;
>>>> +    int dbg2_start = table_data->len;
>>>> +    AcpiDbg2Device *dbg2dev;
>>>> +    char name[] = "COM0";
>>>> +    AcpiDbg2Table *dbg2;
>>>> +    uint32_t *addr_size;
>>>> +    uint8_t *namespace;
>>>> +
>>>> +    dbg2 = acpi_data_push(table_data, sizeof *dbg2);
>>>> +    dbg2->info_offset = sizeof *dbg2;
>>>> +    dbg2->info_count = 1;
>>>> +
>>>> +    /* debug device info structure */
>>>> +
>>>> +    dbg2dev = acpi_data_push(table_data, sizeof(AcpiDbg2Device));
>>>> +
>>>> +    dbg2dev->revision = 0;
>>>> +    namespace_length = sizeof name;
>>>> +    dbg2dev->length = sizeof *dbg2dev + sizeof(struct AcpiGenericAddress) 
>>>> +
>>>> +                      4 + namespace_length;
>>>> +    dbg2dev->register_count = 1;
>>>> +
>>>> +    addr_offset = sizeof *dbg2dev;
>>>> +    addrsize_offset = addr_offset + sizeof(struct AcpiGenericAddress);
>>>> +    namespace_offset = addrsize_offset + 4;
>>>> +
>>>> +    dbg2dev->namepath_length = cpu_to_le16(namespace_length);
>>>> +    dbg2dev->namepath_offset = cpu_to_le16(namespace_offset);
>>>> +    dbg2dev->oem_data_length = cpu_to_le16(0);
>>>> +    dbg2dev->oem_data_offset = cpu_to_le16(0); /* No OEM data is present 
>>>> */
>>>> +    dbg2dev->port_type = cpu_to_le16(ACPI_DBG2_SERIAL_PORT);
>>>> +    dbg2dev->port_subtype = cpu_to_le16(ACPI_DBG2_ARM_PL011);
>>>> +
>>>> +    dbg2dev->base_address_offset = cpu_to_le16(addr_offset);
>>>> +    dbg2dev->address_size_offset = cpu_to_le16(addrsize_offset);
>>>> +
>>>> +    /*
>>>> +     * variable length content:
>>>> +     * BaseAddressRegister[1]
>>>> +     * AddressSize[1]
>>>> +     * NamespaceString[1]
>>>> +     */
>>>> +
>>>> +    base_address = acpi_data_push(table_data,
>>>> +                                  sizeof(struct AcpiGenericAddress));
>>>> +
>>>> +    base_address->space_id = AML_SYSTEM_MEMORY;
>>>> +    base_address->bit_width = 8;
>>>> +    base_address->bit_offset = 0;
>>>> +    base_address->access_width = 1;
>>>> +    base_address->address = cpu_to_le64(uart_memmap->base);
>>>> +
>>>> +    addr_size = acpi_data_push(table_data, sizeof *addr_size);
>>>> +    *addr_size = cpu_to_le32(ACPI_DBG2_PL011_UART_LENGTH);
>>>> +
>>>> +    namespace = acpi_data_push(table_data, namespace_length);
>>>> +    memcpy(namespace, name, namespace_length);
>>>> +
>>>> +    build_header(linker, table_data,
>>>> +                 (void *)(table_data->data + dbg2_start), "DBG2",
>>>> +                 table_data->len - dbg2_start, 3, vms->oem_id,
>>>> +                 vms->oem_table_id);
>>>> +}
>>>> +
>>>>  /* MADT */
>>>>  static void
>>>>  build_madt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
>>>> @@ -790,7 +862,7 @@ void virt_acpi_build(VirtMachineState *vms, 
>>>> AcpiBuildTables *tables)
>>>>      dsdt = tables_blob->len;
>>>>      build_dsdt(tables_blob, tables->linker, vms);
>>>>  
>>>> -    /* FADT MADT GTDT MCFG SPCR pointed to by RSDT */
>>>> +    /* FADT MADT GTDT MCFG SPCR DBG2 pointed to by RSDT */
>>>>      acpi_add_table(table_offsets, tables_blob);
>>>>      build_fadt_rev5(tables_blob, tables->linker, vms, dsdt);
>>>>  
>>>> @@ -813,6 +885,9 @@ void virt_acpi_build(VirtMachineState *vms, 
>>>> AcpiBuildTables *tables)
>>>>      acpi_add_table(table_offsets, tables_blob);
>>>>      build_spcr(tables_blob, tables->linker, vms);
>>>>  
>>>> +    acpi_add_table(table_offsets, tables_blob);
>>>> +    build_dbg2(tables_blob, tables->linker, vms);
>>>> +
>>>>      if (vms->ras) {
>>>>          build_ghes_error_table(tables->hardware_errors, tables->linker);
>>>>          acpi_add_table(table_offsets, tables_blob);
>>>> diff --git a/include/hw/acpi/acpi-defs.h b/include/hw/acpi/acpi-defs.h
>>>> index cf9f44299c..bdb2ebed2c 100644
>>>> --- a/include/hw/acpi/acpi-defs.h
>>>> +++ b/include/hw/acpi/acpi-defs.h
>>>> @@ -618,4 +618,54 @@ struct AcpiIortRC {
>>>>  } QEMU_PACKED;
>>>>  typedef struct AcpiIortRC AcpiIortRC;
>>>>  
>>>> +/* DBG2 */
>>>> +
>>>> +/* Types for port_type field above */
>>>> +
>>>> +#define ACPI_DBG2_SERIAL_PORT       0x8000
>>>> +#define ACPI_DBG2_1394_PORT         0x8001
>>>> +#define ACPI_DBG2_USB_PORT          0x8002
>>>> +#define ACPI_DBG2_NET_PORT          0x8003
>>>> +
>>>> +/* Subtypes for port_subtype field above */
>>>> +
>>>> +#define ACPI_DBG2_16550_COMPATIBLE  0x0000
>>>> +#define ACPI_DBG2_16550_SUBSET      0x0001
>>>> +#define ACPI_DBG2_ARM_PL011         0x0003
>>>> +#define ACPI_DBG2_ARM_SBSA_32BIT    0x000D
>>>> +#define ACPI_DBG2_ARM_SBSA_GENERIC  0x000E
>>>> +#define ACPI_DBG2_ARM_DCC           0x000F
>>>> +#define ACPI_DBG2_BCM2835           0x0010
>>>> +
>>>> +#define ACPI_DBG2_1394_STANDARD     0x0000
>>>> +
>>>> +#define ACPI_DBG2_USB_XHCI          0x0000
>>>> +#define ACPI_DBG2_USB_EHCI          0x0001
>>>> +
>>>> +/* Debug Device Information Subtable */
>>>> +
>>>> +struct AcpiDbg2Device {
>>>> +    uint8_t  revision;
>>>> +    uint16_t length;
>>>> +    uint8_t  register_count; /* Number of base_address registers */
>>>> +    uint16_t namepath_length;
>>>> +    uint16_t namepath_offset;
>>>> +    uint16_t oem_data_length;
>>>> +    uint16_t oem_data_offset;
>>>> +    uint16_t port_type;
>>>> +    uint16_t port_subtype;
>>>> +    uint8_t  reserved[2];
>>>> +    uint16_t base_address_offset;
>>>> +    uint16_t address_size_offset;
>>>> +}  QEMU_PACKED;
>>>> +typedef struct AcpiDbg2Device AcpiDbg2Device;
>>>> +
>>>> +struct AcpiDbg2Table {
>>>> +    ACPI_TABLE_HEADER_DEF /* ACPI common table header */
>>>> +    uint32_t info_offset; /* offset to the first debug struct */
>>>> +    uint32_t info_count;  /* number of debug device info struct entries */
>>>> +    uint8_t  dbg2_device_info[];
>>>> +} QEMU_PACKED;
>>>> +typedef struct AcpiDbg2Table AcpiDbg2Table;
>>>> +
>>>>  #endif