Hello Ard,
On 8/10/21 11:36 AM, Ard Biesheuvel wrote:
> On Tue, 10 Aug 2021 at 10:31, Eric Auger <eric.au...@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
>>
> Have the legal issues around this table been resolved in the mean
> time?
I don't know exactly what they are. Adding Al and Jon in the loop they
have more information about this.
How did you resolve the issue for EDK2
(DynamicTablesPkg/Library/Acpi/Arm/AcpiDbg2LibArm/Dbg2Generator.c)?
> Also, any clue why this table is mandatory to begin with? The
> SBBR has been very trigger happy lately with making things mandatory
> that aren't truly required from a functional perspective.
It seems there are kernel FW test suites that check all mandated tables
are available and they currently fail for ARM virt.
Indeed from a function pov, I don't know much about its usage on ARM.
Maybe the SBBR spec should not flag the DBG2 as mandatory and test
suites shall be updated. I think this should be clarified at ARM then,
all the more so if there are legal issues as its spec is owned by Microsoft?
Thanks
Eric
>
>
>> Signed-off-by: Eric Auger <eric.au...@redhat.com>
>>
>> ---
>>
>> 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
>> --
>> 2.26.3
>>
