x86: acpi: Allow the SSDT to be empty

If there is nothing in the SSDT we should not include it in the tables.
Update the implementation to check this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This commit is contained in:
Simon Glass 2020-11-04 09:57:31 -07:00 committed by Bin Meng
parent be1cee11b2
commit 2de4744dae

View File

@ -470,8 +470,9 @@ static void acpi_create_spcr(struct acpi_spcr *spcr)
header->checksum = table_compute_checksum((void *)spcr, header->length);
}
void acpi_create_ssdt(struct acpi_ctx *ctx, struct acpi_table_header *ssdt,
const char *oem_table_id)
static int acpi_create_ssdt(struct acpi_ctx *ctx,
struct acpi_table_header *ssdt,
const char *oem_table_id)
{
memset((void *)ssdt, '\0', sizeof(struct acpi_table_header));
@ -484,9 +485,19 @@ void acpi_create_ssdt(struct acpi_ctx *ctx, struct acpi_table_header *ssdt,
acpi_fill_ssdt(ctx);
/* (Re)calculate length and checksum. */
/* (Re)calculate length and checksum */
ssdt->length = ctx->current - (void *)ssdt;
ssdt->checksum = table_compute_checksum((void *)ssdt, ssdt->length);
log_debug("SSDT at %p, length %x\n", ssdt, ssdt->length);
/* Drop the table if it is empty */
if (ssdt->length == sizeof(struct acpi_table_header)) {
ctx->current = ssdt;
return -ENOENT;
}
acpi_align(ctx);
return 0;
}
/*
@ -596,11 +607,8 @@ ulong write_acpi_tables(ulong start_addr)
debug("ACPI: * SSDT\n");
ssdt = (struct acpi_table_header *)ctx->current;
acpi_create_ssdt(ctx, ssdt, OEM_TABLE_ID);
if (ssdt->length > sizeof(struct acpi_table_header)) {
acpi_inc_align(ctx, ssdt->length);
if (!acpi_create_ssdt(ctx, ssdt, OEM_TABLE_ID))
acpi_add_table(ctx, ssdt);
}
debug("ACPI: * MCFG\n");
mcfg = ctx->current;