diff options
| author |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-12-13 09:55:14 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2019-12-16 12:06:18 +0100 |
| commit | bc94638886ab21f8247d3f7f39573d3feb7d8284 (patch) | |
| tree | e74c747c0b82ced46eae2b09e1a2405fe4fc7b56 /drivers/acpi | |
| parent | Linux 5.5-rc2 (diff) | |
| download | linux-dev-bc94638886ab21f8247d3f7f39573d3feb7d8284.tar.xz linux-dev-bc94638886ab21f8247d3f7f39573d3feb7d8284.zip | |
ACPI: processor: Export function to claim _CST control
The intel_idle driver will be modified to use ACPI _CST subsequently
and it will need to notify the platform firmware of that if
acpi_gbl_FADT.cst_control is set, so add a routine for this purpose,
acpi_processor_claim_cst_control(), to acpi_processor.c (so that it
is always present which is required by intel_idle) and export it
to allow the ACPI processor driver (which is modular) to call it.
No intentional functional impact.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi')
| -rw-r--r-- | drivers/acpi/acpi_processor.c | 25 | ||||
| -rw-r--r-- | drivers/acpi/processor_idle.c | 12 |
2 files changed, 29 insertions, 8 deletions
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c index 2c4dda0787e8..8a53f3c5b70e 100644 --- a/drivers/acpi/acpi_processor.c +++ b/drivers/acpi/acpi_processor.c @@ -705,3 +705,28 @@ void __init acpi_processor_init(void) acpi_scan_add_handler_with_hotplug(&processor_handler, "processor"); acpi_scan_add_handler(&processor_container_handler); } + +#ifdef CONFIG_ACPI_PROCESSOR_CSTATE +/** + * acpi_processor_claim_cst_control - Request _CST control from the platform. + */ +bool acpi_processor_claim_cst_control(void) +{ + static bool cst_control_claimed; + acpi_status status; + + if (!acpi_gbl_FADT.cst_control || cst_control_claimed) + return true; + + status = acpi_os_write_port(acpi_gbl_FADT.smi_command, + acpi_gbl_FADT.cst_control, 8); + if (ACPI_FAILURE(status)) { + pr_warn("ACPI: Failed to claim processor _CST control\n"); + return false; + } + + cst_control_claimed = true; + return true; +} +EXPORT_SYMBOL_GPL(acpi_processor_claim_cst_control); +#endif /* CONFIG_ACPI_PROCESSOR_CSTATE */ diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 2ae95df2e74f..dd737d836c03 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -909,7 +909,6 @@ static int acpi_processor_setup_cstates(struct acpi_processor *pr) static inline void acpi_processor_cstate_first_run_checks(void) { - acpi_status status; static int first_run; if (first_run) @@ -921,13 +920,10 @@ static inline void acpi_processor_cstate_first_run_checks(void) max_cstate); first_run++; - if (acpi_gbl_FADT.cst_control && !nocst) { - status = acpi_os_write_port(acpi_gbl_FADT.smi_command, - acpi_gbl_FADT.cst_control, 8); - if (ACPI_FAILURE(status)) - ACPI_EXCEPTION((AE_INFO, status, - "Notifying BIOS of _CST ability failed")); - } + if (nocst) + return; + + acpi_processor_claim_cst_control(); } #else |