Re: [PATCH v11 06/10] ACPI ERST: build the ACPI ERST table

[Ani Sinha <ani@anisinha.ca>]

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On Wed, Dec 15, 2021 at 23:27 Eric DeVolder <eric.devolder@oracle.com>
wrote:

> Hi Ani,
> Thanks for such quick feedback! One inline response below.
> eric
>
> On 12/15/21 10:33, Ani Sinha wrote:
> > On Wed, Dec 15, 2021 at 9:08 PM Eric DeVolder <eric.devolder@oracle.com>
> 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 | 188
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> >>   1 file changed, 188 insertions(+)
> >>
> >> diff --git a/hw/acpi/erst.c b/hw/acpi/erst.c
> >> index bb6cad4..05177b3 100644
> >> --- a/hw/acpi/erst.c
> >> +++ b/hw/acpi/erst.c
> >> @@ -59,6 +59,27 @@
> >>   #define STATUS_RECORD_STORE_EMPTY     0x04
> >>   #define STATUS_RECORD_NOT_FOUND       0x05
> >>
> >> +/* 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
> >> +
> >>   /* UEFI 2.1: Appendix N Common Platform Error Record */
> >>   #define UEFI_CPER_RECORD_MIN_SIZE 128U
> >>   #define UEFI_CPER_RECORD_LENGTH_OFFSET 20U
> >> @@ -172,6 +193,173 @@ typedef struct {
> >>
> >>   /*******************************************************************/
> >>   /*******************************************************************/
> >> +
> >> +/* 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,
> >> +    uint64_t register_address,
> >> +    uint64_t value)
> >> +{
> >> +    /* ACPI 4.0: Table 17-18 Serialization Instruction Entry */
> >> +    struct AcpiGenericAddress gas;
> >> +    uint64_t mask;
> >> +
> >> +    /* 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;
> >> +    gas.access_width = ctz32(register_bit_width) - 2;
> >> +    gas.address = register_address;
> >> +    build_append_gas_from_struct(table_data, &gas);
> >> +    /* Value */
> >> +    build_append_int_noprefix(table_data, value  , 8);
> >> +    /* Mask */
> >> +    mask = (1ULL << (register_bit_width - 1) << 1) - 1;
> >> +    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;
> >
> > This variable can be eliminated (see below).
> >
> >> +    pcibus_t bar0 = pci_get_bar_addr(PCI_DEVICE(erst_dev), 0);
> >> +    AcpiTable table = { .sig = "ERST", .rev = 1, .oem_id = oem_id,
> >> +                        .oem_table_id = oem_table_id };
> >> +
> >> +    trace_acpi_erst_pci_bar_0(bar0);
> >> +
> >> +    /*
> >> +     * 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));
> >> +
> >> +    /*
> >> +     * Macros for use with construction of the action instructions
> >> +     */
> >> +#define build_read_register(action, width_in_bits, reg) \
> >> +    build_serialization_instruction_entry(table_instruction_data, \
> >> +        action, INST_READ_REGISTER, 0, width_in_bits, \
> >> +        bar0 + reg, 0)
> >> +
> >> +#define build_read_register_value(action, width_in_bits, reg, value) \
> >> +    build_serialization_instruction_entry(table_instruction_data, \
> >> +        action, INST_READ_REGISTER_VALUE, 0, width_in_bits, \
> >> +        bar0 + reg, value)
> >> +
> >> +#define build_write_register(action, width_in_bits, reg, value) \
> >> +    build_serialization_instruction_entry(table_instruction_data, \
> >> +        action, INST_WRITE_REGISTER, 0, width_in_bits, \
> >> +        bar0 + reg, value)
> >> +
> >> +#define build_write_register_value(action, width_in_bits, reg, value) \
> >> +    build_serialization_instruction_entry(table_instruction_data, \
> >> +        action, INST_WRITE_REGISTER_VALUE, 0, width_in_bits, \
> >> +        bar0 + reg, value)
> >> +
> >> +    /* Serialization Instruction Entries */
> >> +    action = ACTION_BEGIN_WRITE_OPERATION;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +
> >> +    action = ACTION_BEGIN_READ_OPERATION;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +
> >> +    action = ACTION_BEGIN_CLEAR_OPERATION;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +
> >> +    action = ACTION_END_OPERATION;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +
> >> +    action = ACTION_SET_RECORD_OFFSET;
> >> +    build_write_register(action, 32, ERST_VALUE_OFFSET, 0);
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +
> >> +    action = ACTION_EXECUTE_OPERATION;
> >> +    build_write_register_value(action, 32, ERST_VALUE_OFFSET,
> >> +        ERST_EXECUTE_OPERATION_MAGIC);
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >
> >
> >
> >> +
> >> +    action = ACTION_CHECK_BUSY_STATUS;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +    build_read_register_value(action, 32, ERST_VALUE_OFFSET, 0x01);
> >> +
> >> +    action = ACTION_GET_COMMAND_STATUS;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +    build_read_register(action, 32, ERST_VALUE_OFFSET);
> >> +
> >> +    action = ACTION_GET_RECORD_IDENTIFIER;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +    build_read_register(action, 64, ERST_VALUE_OFFSET);
> >> +
> >> +    action = ACTION_SET_RECORD_IDENTIFIER;
> >> +    build_write_register(action, 64, ERST_VALUE_OFFSET, 0);
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +
> >> +    action = ACTION_GET_RECORD_COUNT;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +    build_read_register(action, 32, ERST_VALUE_OFFSET);
> >> +
> >> +    action = ACTION_BEGIN_DUMMY_WRITE_OPERATION;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +
> >> +    action = ACTION_GET_ERROR_LOG_ADDRESS_RANGE;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +    build_read_register(action, 64, ERST_VALUE_OFFSET);
> >> +
> >> +    action = ACTION_GET_ERROR_LOG_ADDRESS_LENGTH;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +    build_read_register(action, 64, ERST_VALUE_OFFSET);
> >> +
> >> +    action = ACTION_GET_ERROR_LOG_ADDRESS_RANGE_ATTRIBUTES;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +    build_read_register(action, 32, ERST_VALUE_OFFSET);
> >> +
> >> +    action = ACTION_GET_EXECUTE_OPERATION_TIMINGS;
> >> +    build_write_register_value(action, 32, ERST_ACTION_OFFSET, action);
> >> +    build_read_register(action, 64, ERST_VALUE_OFFSET);
> >
> > if I am reading this right, build_write_register_value() is called
> > with the same parameters, except that action is changing. We can
> > optimize repetative calls with the same parameters.
> >
> > build_read_register can be split into build_read_register_32() and
> > build_read_register_64().
> > So we can have :
> > build_write_register_value(ACTION_GET_EXECUTE_OPERATION_TIMINGS);
> > build_read_register_64(ACTION_GET_EXECUTE_OPERATION_TIMINGS);
> >
>
> If I understand correctly, you are essentially asking for appropriate
> accessor functions.
> I did an inventory and the following would be the list of unique accessors
> needed:
>
> To ACTION register:
>   write_value_32
>
> To VALUE register:
>   write_value_32
>   write_32
>   write_64
>   read_value_32
>   read_32
>   read_64
>
> So that is 7 accessors, which must spell out the access type and register
> name in the macro.
>
> With respect to the comment on eliminating the action variable. Given the
> current code I did miss an
> optimization to avoid passing 'action' as the first parameter to the
> macros; I should have just used
> it directly within the macro. Plus the 'action' assignment acts as
> documentation to inform you as to
> which action is being constructed. But in other places, 'action' is being
> used as a true parameter
> to the macros as the value to write.
>
> If you think that going to more accessors is simpler/more clear, then I'll
> do so.


Let’s wait and see what Michael thinks about this.


>
> Thanks!
> eric
>
>
>
>
> >> +
> >> +    /* 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
> >> +     */
> >> +    g_assert((table_instruction_data->len) % 32 == 0);
> >> +    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 uint8_t *get_nvram_ptr_by_index(ERSTDeviceState *s, unsigned
> index)
> >>   {
> >>       uint8_t *rc = NULL;
> >> --
> >> 1.8.3.1
> >>
>

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