diff --git a/src/soc/amd/common/block/acpi/cpu_power_state.c b/src/soc/amd/common/block/acpi/cpu_power_state.c index 9eb636d7d7..24b08f054a 100644 --- a/src/soc/amd/common/block/acpi/cpu_power_state.c +++ b/src/soc/amd/common/block/acpi/cpu_power_state.c @@ -51,8 +51,19 @@ static size_t get_pstate_info(struct acpi_sw_pstate *pstate_values, return pstate_count; } -static void write_cstate_entry(acpi_cstate_t *entry, const acpi_cstate_t *data, - uint32_t cstate_io_base_address) +static uint16_t get_cstate_io_base_address(void) +{ + static uint16_t cstate_io_base; + + if (cstate_io_base) + return cstate_io_base; + + cstate_io_base = rdmsr(MSR_CSTATE_ADDRESS).lo & MSR_CSTATE_ADDRESS_MASK; + + return cstate_io_base; +} + +static void write_cstate_entry(acpi_cstate_t *entry, const acpi_cstate_t *data) { if (!data->ctype) { printk(BIOS_WARNING, "Invalid C-state data; skipping entry.\n"); @@ -76,9 +87,9 @@ static void write_cstate_entry(acpi_cstate_t *entry, const acpi_cstate_t *data, .space_id = ACPI_ADDRESS_SPACE_IO, .bit_width = 8, .bit_offset = 0, - /* ctype is 1-indexed while the offset into cstate_io_base_address is - 0-indexed */ - .addrl = cstate_io_base_address + data->ctype - 1, + /* ctype is 1-indexed while the offset into the IO address returned by + get_cstate_io_base_address() is 0-indexed */ + .addrl = get_cstate_io_base_address() + data->ctype - 1, .addrh = 0, .access_size = ACPI_ACCESS_SIZE_BYTE_ACCESS, }; @@ -89,8 +100,6 @@ static size_t get_cstate_info(acpi_cstate_t *cstate_values) { size_t i; size_t cstate_count; - uint32_t cstate_io_base_address = - rdmsr(MSR_CSTATE_ADDRESS).lo & MSR_CSTATE_ADDRESS_MASK; const acpi_cstate_t *cstate_config = get_cstate_config_data(&cstate_count); if (cstate_count > MAX_CSTATE_COUNT) { @@ -101,7 +110,7 @@ static size_t get_cstate_info(acpi_cstate_t *cstate_values) } for (i = 0; i < cstate_count; i++) { - write_cstate_entry(&cstate_values[i], &cstate_config[i], cstate_io_base_address); + write_cstate_entry(&cstate_values[i], &cstate_config[i]); } return i;