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* [PATCH v2] xen/acpi: upload _PSD info for non Dom0 CPUs too
@ 2018-03-08 10:57 Joao Martins
  2018-03-08 22:33 ` [Xen-devel] " Boris Ostrovsky
  0 siblings, 1 reply; 3+ messages in thread
From: Joao Martins @ 2018-03-08 10:57 UTC (permalink / raw)
  To: linux-kernel
  Cc: Joao Martins, Boris Ostrovsky, Juergen Gross, Rafael J. Wysocki,
	Len Brown, Robert Moore, Erik Schmauss, xen-devel, linux-acpi,
	devel

All uploaded PM data from non-dom0 CPUs takes the info from vCPU 0 and
changing only the acpi_id. For processors which P-state coordination type
is HW_ALL (0xFD) it is OK to upload bogus P-state dependency information
(_PSD), because Xen will ignore any cpufreq domains created for past CPUs.

Albeit for platforms which expose coordination types as SW_ANY or SW_ALL,
this will have some unintended side effects. Effectively, it will look at
the P-state domain existence and *if it already exists* it will skip the
acpi-cpufreq initialization and thus inherit the policy from the first CPU
in the cpufreq domain. This will finally lead to the original cpu not
changing target freq to P0 other than the first in the domain. Which will
make turbo boost not getting enabled (e.g. for 'performance' governor) for
all cpus.

This patch fixes that, by also evaluating _PSD when enumerate all ACPI
procesors and always uploading the correct info to Xen. We export
acpi_processor_get_psd() to help with this purpose, but change signature
to not assume the existence of a struct acpi_processor given that ACPI
doesn't create an acpi_processor for non-dom0 CPUs.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
---
Changes since v1:
 (Comments from Boris)
 * Refactor acpi_processor_get_psd(), export and use that instead.
 * s/offline/non-dom0/
---
 drivers/acpi/processor_perflib.c | 11 +++++------
 drivers/xen/xen-acpi-processor.c | 37 +++++++++++++++++++++++++++++++++++++
 include/acpi/processor.h         |  2 ++
 3 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index c7cf48ad5cb9..a651ab3490d8 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -533,7 +533,7 @@ int acpi_processor_notify_smm(struct module *calling_module)
 
 EXPORT_SYMBOL(acpi_processor_notify_smm);
 
-static int acpi_processor_get_psd(struct acpi_processor	*pr)
+int acpi_processor_get_psd(acpi_handle handle, struct acpi_psd_package *pdomain)
 {
 	int result = 0;
 	acpi_status status = AE_OK;
@@ -541,9 +541,8 @@ static int acpi_processor_get_psd(struct acpi_processor	*pr)
 	struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};
 	struct acpi_buffer state = {0, NULL};
 	union acpi_object  *psd = NULL;
-	struct acpi_psd_package *pdomain;
 
-	status = acpi_evaluate_object(pr->handle, "_PSD", NULL, &buffer);
+	status = acpi_evaluate_object(handle, "_PSD", NULL, &buffer);
 	if (ACPI_FAILURE(status)) {
 		return -ENODEV;
 	}
@@ -561,8 +560,6 @@ static int acpi_processor_get_psd(struct acpi_processor	*pr)
 		goto end;
 	}
 
-	pdomain = &(pr->performance->domain_info);
-
 	state.length = sizeof(struct acpi_psd_package);
 	state.pointer = pdomain;
 
@@ -597,6 +594,7 @@ static int acpi_processor_get_psd(struct acpi_processor	*pr)
 	kfree(buffer.pointer);
 	return result;
 }
+EXPORT_SYMBOL(acpi_processor_get_psd);
 
 int acpi_processor_preregister_performance(
 		struct acpi_processor_performance __percpu *performance)
@@ -645,7 +643,8 @@ int acpi_processor_preregister_performance(
 
 		pr->performance = per_cpu_ptr(performance, i);
 		cpumask_set_cpu(i, pr->performance->shared_cpu_map);
-		if (acpi_processor_get_psd(pr)) {
+		pdomain = &(pr->performance->domain_info);
+		if (acpi_processor_get_psd(pr->handle, pdomain)) {
 			retval = -EINVAL;
 			continue;
 		}
diff --git a/drivers/xen/xen-acpi-processor.c b/drivers/xen/xen-acpi-processor.c
index 23e391d3ec01..e4f49d23a593 100644
--- a/drivers/xen/xen-acpi-processor.c
+++ b/drivers/xen/xen-acpi-processor.c
@@ -53,6 +53,10 @@ static unsigned long *acpi_ids_done;
 static unsigned long *acpi_id_present;
 /* And if there is an _CST definition (or a PBLK) for the ACPI IDs */
 static unsigned long *acpi_id_cst_present;
+/* And if there is an _PSD definition for the ACPI IDs */
+static unsigned long *acpi_id_psd_present;
+/* Which ACPI P-State dependencies for a enumerated processor */
+static struct acpi_psd_package *acpi_psd;
 
 static int push_cxx_to_hypervisor(struct acpi_processor *_pr)
 {
@@ -372,6 +376,15 @@ read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv)
 
 	pr_debug("ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id, (unsigned long)pblk);
 
+	/* It has P-state dependencies */
+	if (!acpi_processor_get_psd(handle, &acpi_psd[acpi_id])) {
+		__set_bit(acpi_id, acpi_id_psd_present);
+
+		pr_debug("ACPI CPU%u w/ PST:coord_type = %llu domain = %llu\n",
+			 acpi_id, acpi_psd[acpi_id].coord_type,
+			 acpi_psd[acpi_id].domain);
+	}
+
 	status = acpi_evaluate_object(handle, "_CST", NULL, &buffer);
 	if (ACPI_FAILURE(status)) {
 		if (!pblk)
@@ -405,6 +418,23 @@ static int check_acpi_ids(struct acpi_processor *pr_backup)
 		return -ENOMEM;
 	}
 
+	acpi_id_psd_present = kcalloc(BITS_TO_LONGS(nr_acpi_bits),
+				      sizeof(unsigned long), GFP_KERNEL);
+	if (!acpi_id_psd_present) {
+		kfree(acpi_id_present);
+		kfree(acpi_id_cst_present);
+		return -ENOMEM;
+	}
+
+	acpi_psd = kcalloc(nr_acpi_bits, sizeof(struct acpi_psd_package),
+			   GFP_KERNEL);
+	if (!acpi_psd) {
+		kfree(acpi_id_present);
+		kfree(acpi_id_cst_present);
+		kfree(acpi_id_psd_present);
+		return -ENOMEM;
+	}
+
 	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
 			    ACPI_UINT32_MAX,
 			    read_acpi_id, NULL, NULL, NULL);
@@ -417,6 +447,11 @@ static int check_acpi_ids(struct acpi_processor *pr_backup)
 			pr_backup->acpi_id = i;
 			/* Mask out C-states if there are no _CST or PBLK */
 			pr_backup->flags.power = test_bit(i, acpi_id_cst_present);
+			if (test_bit(i, acpi_id_psd_present)) {
+				memcpy(&pr_backup->performance->domain_info,
+				       &acpi_psd[i],
+				       sizeof(struct acpi_psd_package));
+			}
 			(void)upload_pm_data(pr_backup);
 		}
 	}
@@ -566,6 +601,8 @@ static void __exit xen_acpi_processor_exit(void)
 	kfree(acpi_ids_done);
 	kfree(acpi_id_present);
 	kfree(acpi_id_cst_present);
+	kfree(acpi_id_psd_present);
+	kfree(acpi_psd);
 	for_each_possible_cpu(i)
 		acpi_processor_unregister_performance(i);
 
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index d591bb77f592..40a916efd7c0 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -254,6 +254,8 @@ int acpi_processor_pstate_control(void);
 /* note: this locks both the calling module and the processor module
          if a _PPC object exists, rmmod is disallowed then */
 int acpi_processor_notify_smm(struct module *calling_module);
+int acpi_processor_get_psd(acpi_handle handle,
+			   struct acpi_psd_package *pdomain);
 
 /* parsing the _P* objects. */
 extern int acpi_processor_get_performance_info(struct acpi_processor *pr);
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [Xen-devel] [PATCH v2] xen/acpi: upload _PSD info for non Dom0 CPUs too
  2018-03-08 10:57 [PATCH v2] xen/acpi: upload _PSD info for non Dom0 CPUs too Joao Martins
@ 2018-03-08 22:33 ` Boris Ostrovsky
  2018-03-09 12:56   ` Joao Martins
  0 siblings, 1 reply; 3+ messages in thread
From: Boris Ostrovsky @ 2018-03-08 22:33 UTC (permalink / raw)
  To: Joao Martins, linux-kernel
  Cc: Juergen Gross, Rafael J. Wysocki, Robert Moore, linux-acpi,
	xen-devel, devel, Erik Schmauss, Len Brown



On 03/08/2018 05:57 AM, Joao Martins wrote:

> @@ -372,6 +376,15 @@ read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv)
>   
>   	pr_debug("ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id, (unsigned long)pblk);
>   
> +	/* It has P-state dependencies */
> +	if (!acpi_processor_get_psd(handle, &acpi_psd[acpi_id])) {
> +		__set_bit(acpi_id, acpi_id_psd_present);
> +
> +		pr_debug("ACPI CPU%u w/ PST:coord_type = %llu domain = %llu\n",
> +			 acpi_id, acpi_psd[acpi_id].coord_type,
> +			 acpi_psd[acpi_id].domain);
> +	}


I should have noticed this earlier, but do you really need 
acpi_id_psd_present? Can you just go by acpi_psd[i] != NULL?

Sorry for missing it in the first patch.

-boris

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [Xen-devel] [PATCH v2] xen/acpi: upload _PSD info for non Dom0 CPUs too
  2018-03-08 22:33 ` [Xen-devel] " Boris Ostrovsky
@ 2018-03-09 12:56   ` Joao Martins
  0 siblings, 0 replies; 3+ messages in thread
From: Joao Martins @ 2018-03-09 12:56 UTC (permalink / raw)
  To: Boris Ostrovsky
  Cc: linux-kernel, Juergen Gross, Rafael J. Wysocki, Robert Moore,
	linux-acpi, xen-devel, Len Brown, Erik Schmauss, devel

On 03/08/2018 10:33 PM, Boris Ostrovsky wrote:
> On 03/08/2018 05:57 AM, Joao Martins wrote:
> 
>> @@ -372,6 +376,15 @@ read_acpi_id(acpi_handle handle, u32 lvl, void *context, void **rv)
>>   
>>   	pr_debug("ACPI CPU%u w/ PBLK:0x%lx\n", acpi_id, (unsigned long)pblk);
>>   
>> +	/* It has P-state dependencies */
>> +	if (!acpi_processor_get_psd(handle, &acpi_psd[acpi_id])) {
>> +		__set_bit(acpi_id, acpi_id_psd_present);
>> +
>> +		pr_debug("ACPI CPU%u w/ PST:coord_type = %llu domain = %llu\n",
>> +			 acpi_id, acpi_psd[acpi_id].coord_type,
>> +			 acpi_psd[acpi_id].domain);
>> +	}
> 
> 
> I should have noticed this earlier, but do you really need 
> acpi_id_psd_present? Can you just go by acpi_psd[i] != NULL?
>

Oh yes! I was trying to be consistent with the rest of the module, but we surely
don't need that array of longs. Will respin after testing.

> Sorry for missing it in the first patch.
>
Thanks for the feedback!

> -boris
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xenproject.org
> https://lists.xenproject.org/mailman/listinfo/xen-devel
> 

^ permalink raw reply	[flat|nested] 3+ messages in thread

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2018-03-08 10:57 [PATCH v2] xen/acpi: upload _PSD info for non Dom0 CPUs too Joao Martins
2018-03-08 22:33 ` [Xen-devel] " Boris Ostrovsky
2018-03-09 12:56   ` Joao Martins

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