Re: [PATCH v10 06/10] ACPI ERST: build the ACPI ERST table

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Dec 09, 2021 at 12:57:31PM -0500, Eric DeVolder wrote:
> This builds the ACPI ERST table to inform OSPM how to communicate
> with the acpi-erst device.
> 
> Signed-off-by: Eric DeVolder <eric.devolder@oracle.com>
> ---
>  hw/acpi/erst.c | 241 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 241 insertions(+)
> 
> diff --git a/hw/acpi/erst.c b/hw/acpi/erst.c
> index 81f5435..753425a 100644
> --- a/hw/acpi/erst.c
> +++ b/hw/acpi/erst.c
> @@ -711,6 +711,247 @@ static const MemoryRegionOps erst_reg_ops = {
>      .endianness = DEVICE_NATIVE_ENDIAN,
>  };
>  
> +
> +/*******************************************************************/
> +/*******************************************************************/
> +
> +/* ACPI 4.0: Table 17-19 Serialization Instructions */
> +#define INST_READ_REGISTER                 0x00
> +#define INST_READ_REGISTER_VALUE           0x01
> +#define INST_WRITE_REGISTER                0x02
> +#define INST_WRITE_REGISTER_VALUE          0x03
> +#define INST_NOOP                          0x04
> +#define INST_LOAD_VAR1                     0x05
> +#define INST_LOAD_VAR2                     0x06
> +#define INST_STORE_VAR1                    0x07
> +#define INST_ADD                           0x08
> +#define INST_SUBTRACT                      0x09
> +#define INST_ADD_VALUE                     0x0A
> +#define INST_SUBTRACT_VALUE                0x0B
> +#define INST_STALL                         0x0C
> +#define INST_STALL_WHILE_TRUE              0x0D
> +#define INST_SKIP_NEXT_INSTRUCTION_IF_TRUE 0x0E
> +#define INST_GOTO                          0x0F
> +#define INST_SET_SRC_ADDRESS_BASE          0x10
> +#define INST_SET_DST_ADDRESS_BASE          0x11
> +#define INST_MOVE_DATA                     0x12
> +

I would create wrappers for the specific uses that we do have. Leave the
rest alone.
You just use 4 of these right? And a bunch of parameters are
always the same. E.g. flags always 0, address always same.

> +/* ACPI 4.0: 17.4.1.2 Serialization Instruction Entries */
> +static void build_serialization_instruction_entry(GArray *table_data,
> +    uint8_t serialization_action,
> +    uint8_t instruction,
> +    uint8_t flags,
> +    uint8_t register_bit_width,

maybe make it width in bytes, then you do not need a switch.

> +    uint64_t register_address,
> +    uint64_t value,
> +    uint64_t mask)
> +{
> +    /* ACPI 4.0: Table 17-18 Serialization Instruction Entry */
> +    struct AcpiGenericAddress gas;
> +
> +    /* Serialization Action */
> +    build_append_int_noprefix(table_data, serialization_action, 1);
> +    /* Instruction */
> +    build_append_int_noprefix(table_data, instruction         , 1);
> +    /* Flags */
> +    build_append_int_noprefix(table_data, flags               , 1);
> +    /* Reserved */
> +    build_append_int_noprefix(table_data, 0                   , 1);
> +    /* Register Region */
> +    gas.space_id = AML_SYSTEM_MEMORY;
> +    gas.bit_width = register_bit_width;
> +    gas.bit_offset = 0;
> +    switch (register_bit_width) {
> +    case 8:
> +        gas.access_width = 1;
> +        break;
> +    case 16:
> +        gas.access_width = 2;
> +        break;
> +    case 32:
> +        gas.access_width = 3;
> +        break;
> +    case 64:
> +        gas.access_width = 4;
> +        break;
> +    default:
> +        gas.access_width = 0;
> +        break;

does this default actually work?

> +    }
> +    gas.address = register_address;
> +    build_append_gas_from_struct(table_data, &gas);
> +    /* Value */
> +    build_append_int_noprefix(table_data, value  , 8);
> +    /* Mask */
> +    build_append_int_noprefix(table_data, mask   , 8);
> +}
> +
> +/* ACPI 4.0: 17.4.1 Serialization Action Table */
> +void build_erst(GArray *table_data, BIOSLinker *linker, Object *erst_dev,
> +    const char *oem_id, const char *oem_table_id)
> +{
> +    GArray *table_instruction_data;
> +    unsigned action;
> +    pcibus_t bar0, bar1;
> +    AcpiTable table = { .sig = "ERST", .rev = 1, .oem_id = oem_id,
> +                        .oem_table_id = oem_table_id };
> +
> +    bar0 = (pcibus_t)pci_get_bar_addr(PCI_DEVICE(erst_dev), 0);
> +    trace_acpi_erst_pci_bar_0(bar0);
> +    bar1 = (pcibus_t)pci_get_bar_addr(PCI_DEVICE(erst_dev), 1);

why do we need the cast here?
Also assignment at declaration point will be cleaner, won't it?

> +    trace_acpi_erst_pci_bar_1(bar1);

bar1 seems unused ... why do we bother with it just for trace?

> +
> +#define MASK8  0x00000000000000FFUL
> +#define MASK16 0x000000000000FFFFUL
> +#define MASK32 0x00000000FFFFFFFFUL
> +#define MASK64 0xFFFFFFFFFFFFFFFFUL


can't we just pass # of bytes?

> +
> +    /*
> +     * Serialization Action Table
> +     * The serialization action table must be generated first
> +     * so that its size can be known in order to populate the
> +     * Instruction Entry Count field.
> +     */
> +    table_instruction_data = g_array_new(FALSE, FALSE, sizeof(char));
> +
> +    /* Serialization Instruction Entries */
> +    action = ACTION_BEGIN_WRITE_OPERATION;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +
> +    action = ACTION_BEGIN_READ_OPERATION;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +
> +    action = ACTION_BEGIN_CLEAR_OPERATION;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +
> +    action = ACTION_END_OPERATION;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +
> +    action = ACTION_SET_RECORD_OFFSET;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER      , 0, 32,
> +        bar0 + ERST_VALUE_OFFSET , 0, MASK32);
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +
> +    action = ACTION_EXECUTE_OPERATION;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_VALUE_OFFSET , ERST_EXECUTE_OPERATION_MAGIC, MASK8);
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +
> +    action = ACTION_CHECK_BUSY_STATUS;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_READ_REGISTER_VALUE , 0, 32,
> +        bar0 + ERST_VALUE_OFFSET, 0x01, MASK8);
> +
> +    action = ACTION_GET_COMMAND_STATUS;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_READ_REGISTER       , 0, 32,
> +        bar0 + ERST_VALUE_OFFSET, 0, MASK8);
> +
> +    action = ACTION_GET_RECORD_IDENTIFIER;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_READ_REGISTER       , 0, 64,
> +        bar0 + ERST_VALUE_OFFSET, 0, MASK64);
> +
> +    action = ACTION_SET_RECORD_IDENTIFIER;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER      , 0, 64,
> +        bar0 + ERST_VALUE_OFFSET , 0, MASK64);
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +
> +    action = ACTION_GET_RECORD_COUNT;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_READ_REGISTER       , 0, 32,
> +        bar0 + ERST_VALUE_OFFSET, 0, MASK32);
> +
> +    action = ACTION_BEGIN_DUMMY_WRITE_OPERATION;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +
> +    action = ACTION_GET_ERROR_LOG_ADDRESS_RANGE;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_READ_REGISTER       , 0, 64,
> +        bar0 + ERST_VALUE_OFFSET, 0, MASK64);
> +
> +    action = ACTION_GET_ERROR_LOG_ADDRESS_LENGTH;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_READ_REGISTER       , 0, 64,
> +        bar0 + ERST_VALUE_OFFSET, 0, MASK32);
> +
> +    action = ACTION_GET_ERROR_LOG_ADDRESS_RANGE_ATTRIBUTES;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_READ_REGISTER       , 0, 32,
> +        bar0 + ERST_VALUE_OFFSET, 0, MASK32);
> +
> +    action = ACTION_GET_EXECUTE_OPERATION_TIMINGS;
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_WRITE_REGISTER_VALUE, 0, 32,
> +        bar0 + ERST_ACTION_OFFSET, action, MASK8);
> +    build_serialization_instruction_entry(table_instruction_data,
> +        action, INST_READ_REGISTER       , 0, 64,
> +        bar0 + ERST_VALUE_OFFSET, 0, MASK64);
> +
> +    /* Serialization Header */
> +    acpi_table_begin(&table, table_data);
> +
> +    /* Serialization Header Size */
> +    build_append_int_noprefix(table_data, 48, 4);
> +
> +    /* Reserved */
> +    build_append_int_noprefix(table_data,  0, 4);
> +
> +    /*
> +     * Instruction Entry Count
> +     * Each instruction entry is 32 bytes
> +     */

assert that it's a multiple of 32 maybe

> +    build_append_int_noprefix(table_data,
> +        (table_instruction_data->len / 32), 4);
> +
> +    /* Serialization Instruction Entries */
> +    g_array_append_vals(table_data, table_instruction_data->data,
> +        table_instruction_data->len);
> +    g_array_free(table_instruction_data, TRUE);
> +
> +    acpi_table_end(linker, &table);
> +}
> +
>  /*******************************************************************/
>  /*******************************************************************/
>  static int erst_post_load(void *opaque, int version_id)
> -- 
> 1.8.3.1