From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Linux PM <linux-pm@vger.kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
Linux ACPI <linux-acpi@vger.kernel.org>,
Len Brown <len.brown@intel.com>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Len Brown <lenb@kernel.org>
Subject: [RFC v2][PATCH 1/9] ACPI: processor: Export function to claim _CST control
Date: Tue, 10 Dec 2019 13:01:53 +0100 [thread overview]
Message-ID: <2412445.rh3VWn84Qd@kreacher> (raw)
In-Reply-To: <35821518.IbFVMVmUy3@kreacher>
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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>
---
No changes from the previous version.
---
drivers/acpi/acpi_processor.c | 25 +++++++++++++++++++++++++
drivers/acpi/processor_idle.c | 12 ++++--------
include/linux/acpi.h | 6 ++++++
3 files changed, 35 insertions(+), 8 deletions(-)
Index: linux-pm/drivers/acpi/acpi_processor.c
===================================================================
--- linux-pm.orig/drivers/acpi/acpi_processor.c
+++ linux-pm/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 */
Index: linux-pm/drivers/acpi/processor_idle.c
===================================================================
--- linux-pm.orig/drivers/acpi/processor_idle.c
+++ linux-pm/drivers/acpi/processor_idle.c
@@ -909,7 +909,6 @@ static int acpi_processor_setup_cstates(
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
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
Index: linux-pm/include/linux/acpi.h
===================================================================
--- linux-pm.orig/include/linux/acpi.h
+++ linux-pm/include/linux/acpi.h
@@ -279,6 +279,12 @@ static inline bool invalid_phys_cpuid(ph
/* Validate the processor object's proc_id */
bool acpi_duplicate_processor_id(int proc_id);
+/* Processor _CTS control */
+#ifdef CONFIG_ACPI_PROCESSOR_CSTATE
+bool acpi_processor_claim_cst_control(void);
+#else
+static inline bool acpi_processor_claim_cst_control(void) { return false; }
+#endif
#ifdef CONFIG_ACPI_HOTPLUG_CPU
/* Arch dependent functions for cpu hotplug support */
next prev parent reply other threads:[~2019-12-10 12:13 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-10 11:54 [RFC v2][PATCH 0/9] cpuidle: intel_idle: Use ACPI _CTS to get idle states information Rafael J. Wysocki
2019-12-10 12:01 ` Rafael J. Wysocki [this message]
2019-12-10 12:02 ` [RFC v2][PATCH 2/9] ACPI: processor: Introduce acpi_processor_evaluate_cst() Rafael J. Wysocki
2019-12-10 12:02 ` [RFC v2][PATCH 3/9] ACPI: processor: Clean up acpi_processor_evaluate_cst() Rafael J. Wysocki
2019-12-10 12:02 ` [RFC v2][PATCH 4/9] ACPI: processor: Export acpi_processor_evaluate_cst() Rafael J. Wysocki
2019-12-10 12:03 ` [RFC v2][PATCH 5/9] intel_idle: Refactor intel_idle_cpuidle_driver_init() Rafael J. Wysocki
2019-12-10 12:06 ` [RFC v2][PATCH 6/9] intel_idle: Use ACPI _CST for processor models without C-state tables Rafael J. Wysocki
2019-12-10 12:07 ` [RFC v2][PATCH 7/9] cpuidle: Allow idle states to be disabled by default Rafael J. Wysocki
2019-12-10 12:13 ` [RFC v2][PATCH 8/9] intel_idle: Use ACPI _CST for selected known processors Rafael J. Wysocki
2019-12-10 12:13 ` [RFC v2][PATCH 9/9] intel_idle: Add module parameter to prevent ACPI _CST from being used Rafael J. Wysocki
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