6.6-stable review patch. If anyone has any objections, please let me know.
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From: Ricardo Neri ricardo.neri-calderon@linux.intel.com
[ Upstream commit 1c53081d773c2cb4461636559b0d55b46559ceec ]
In preparation to support hibernation, add functionality to disable an HFI instance during CPU offline. The last CPU of an instance that goes offline will disable such instance.
The Intel Software Development Manual states that the operating system must wait for the hardware to set MSR_IA32_PACKAGE_THERM_STATUS[26] after disabling an HFI instance to ensure that it will no longer write on the HFI memory. Some processors, however, do not ever set such bit. Wait a minimum of 2ms to give time hardware to complete any pending memory writes.
Signed-off-by: Ricardo Neri ricardo.neri-calderon@linux.intel.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Stable-dep-of: 97566d09fd02 ("thermal: intel: hfi: Add syscore callbacks for system-wide PM") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/thermal/intel/intel_hfi.c | 35 +++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+)
diff --git a/drivers/thermal/intel/intel_hfi.c b/drivers/thermal/intel/intel_hfi.c index 820613e293cd..bb25c75acd45 100644 --- a/drivers/thermal/intel/intel_hfi.c +++ b/drivers/thermal/intel/intel_hfi.c @@ -24,6 +24,7 @@ #include <linux/bitops.h> #include <linux/cpufeature.h> #include <linux/cpumask.h> +#include <linux/delay.h> #include <linux/gfp.h> #include <linux/io.h> #include <linux/kernel.h> @@ -367,6 +368,32 @@ static void hfi_set_hw_table(struct hfi_instance *hfi_instance) wrmsrl(MSR_IA32_HW_FEEDBACK_PTR, msr_val); }
+/* Caller must hold hfi_instance_lock. */ +static void hfi_disable(void) +{ + u64 msr_val; + int i; + + rdmsrl(MSR_IA32_HW_FEEDBACK_CONFIG, msr_val); + msr_val &= ~HW_FEEDBACK_CONFIG_HFI_ENABLE_BIT; + wrmsrl(MSR_IA32_HW_FEEDBACK_CONFIG, msr_val); + + /* + * Wait for hardware to acknowledge the disabling of HFI. Some + * processors may not do it. Wait for ~2ms. This is a reasonable + * time for hardware to complete any pending actions on the HFI + * memory. + */ + for (i = 0; i < 2000; i++) { + rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val); + if (msr_val & PACKAGE_THERM_STATUS_HFI_UPDATED) + break; + + udelay(1); + cpu_relax(); + } +} + /** * intel_hfi_online() - Enable HFI on @cpu * @cpu: CPU in which the HFI will be enabled @@ -421,6 +448,10 @@ void intel_hfi_online(unsigned int cpu) /* * Hardware is programmed with the physical address of the first page * frame of the table. Hence, the allocated memory must be page-aligned. + * + * Some processors do not forget the initial address of the HFI table + * even after having been reprogrammed. Keep using the same pages. Do + * not free them. */ hfi_instance->hw_table = alloc_pages_exact(hfi_features.nr_table_pages, GFP_KERNEL | __GFP_ZERO); @@ -485,6 +516,10 @@ void intel_hfi_offline(unsigned int cpu)
mutex_lock(&hfi_instance_lock); cpumask_clear_cpu(cpu, hfi_instance->cpus); + + if (!cpumask_weight(hfi_instance->cpus)) + hfi_disable(); + mutex_unlock(&hfi_instance_lock); }