diff options
| -rw-r--r-- | arch/x86/include/asm/acpi_table.h | 3 | ||||
| -rw-r--r-- | arch/x86/lib/acpi_table.c | 26 |
2 files changed, 29 insertions, 0 deletions
diff --git a/arch/x86/include/asm/acpi_table.h b/arch/x86/include/asm/acpi_table.h index ff4802a..56aa282 100644 --- a/arch/x86/include/asm/acpi_table.h +++ b/arch/x86/include/asm/acpi_table.h @@ -296,6 +296,9 @@ struct acpi_mcfg_mmconfig { u8 reserved[4]; }; +/* PM1_CNT bit defines */ +#define PM1_CNT_SCI_EN (1 << 0) + /* These can be used by the target port */ void acpi_fill_header(struct acpi_table_header *header, char *signature); diff --git a/arch/x86/lib/acpi_table.c b/arch/x86/lib/acpi_table.c index be7b824..855d4a0 100644 --- a/arch/x86/lib/acpi_table.c +++ b/arch/x86/lib/acpi_table.c @@ -12,6 +12,7 @@ #include <dm.h> #include <dm/uclass-internal.h> #include <asm/acpi_table.h> +#include <asm/io.h> #include <asm/lapic.h> #include <asm/tables.h> @@ -301,6 +302,25 @@ static void acpi_create_mcfg(struct acpi_mcfg *mcfg) header->checksum = table_compute_checksum((void *)mcfg, header->length); } +static void enter_acpi_mode(int pm1_cnt) +{ + /* + * PM1_CNT register bit0 selects the power management event to be + * either an SCI or SMI interrupt. When this bit is set, then power + * management events will generate an SCI interrupt. When this bit + * is reset power management events will generate an SMI interrupt. + * + * Per ACPI spec, it is the responsibility of the hardware to set + * or reset this bit. OSPM always preserves this bit position. + * + * U-Boot does not support SMI. And we don't have plan to support + * anything running in SMM within U-Boot. To create a legacy-free + * system, and expose ourselves to OSPM as working under ACPI mode + * already, turn this bit on. + */ + outw(PM1_CNT_SCI_EN, pm1_cnt); +} + /* * QEMU's version of write_acpi_tables is defined in * arch/x86/cpu/qemu/acpi_table.c @@ -400,5 +420,11 @@ u32 write_acpi_tables(u32 start) debug("ACPI: done\n"); + /* + * Other than waiting for OSPM to request us to switch to ACPI mode, + * do it by ourselves, since SMI will not be triggered. + */ + enter_acpi_mode(fadt->pm1a_cnt_blk); + return current; } |