[PATCH V3 1/2] platform/x86/intel/pmc: Refactor platform resume functions to use cnl_resume()

[PATCH V3 1/2] platform/x86/intel/pmc: Refactor platform resume functions to use cnl_resume()

[David E. Box]

Several platform resume functions currently call pmc_core_send_ltr_ignore()
and pmc_core_resume_common(), both of which are already called by
cnl_resume(). Simplify the code by having these functions call cnl_resume()
directly.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
---
V3 - no change

V2 - New patch. Split from V1

 drivers/platform/x86/intel/pmc/arl.c | 3 +--
 drivers/platform/x86/intel/pmc/lnl.c | 3 +--
 drivers/platform/x86/intel/pmc/mtl.c | 3 +--
 3 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/platform/x86/intel/pmc/arl.c b/drivers/platform/x86/intel/pmc/arl.c
index e10527c4e3e0..05dec4f5019f 100644
--- a/drivers/platform/x86/intel/pmc/arl.c
+++ b/drivers/platform/x86/intel/pmc/arl.c
@@ -687,9 +687,8 @@ static void arl_d3_fixup(void)
 static int arl_resume(struct pmc_dev *pmcdev)
 {
 	arl_d3_fixup();
-	pmc_core_send_ltr_ignore(pmcdev, 3, 0);
 
-	return pmc_core_resume_common(pmcdev);
+	return cnl_resume(pmcdev);
 }
 
 int arl_core_init(struct pmc_dev *pmcdev)
diff --git a/drivers/platform/x86/intel/pmc/lnl.c b/drivers/platform/x86/intel/pmc/lnl.c
index e7a8077d1a3e..be029f12cdf4 100644
--- a/drivers/platform/x86/intel/pmc/lnl.c
+++ b/drivers/platform/x86/intel/pmc/lnl.c
@@ -546,9 +546,8 @@ static void lnl_d3_fixup(void)
 static int lnl_resume(struct pmc_dev *pmcdev)
 {
 	lnl_d3_fixup();
-	pmc_core_send_ltr_ignore(pmcdev, 3, 0);
 
-	return pmc_core_resume_common(pmcdev);
+	return cnl_resume(pmcdev);
 }
 
 int lnl_core_init(struct pmc_dev *pmcdev)
diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
index 91f2fa728f5c..fc6a89b8979f 100644
--- a/drivers/platform/x86/intel/pmc/mtl.c
+++ b/drivers/platform/x86/intel/pmc/mtl.c
@@ -988,9 +988,8 @@ static void mtl_d3_fixup(void)
 static int mtl_resume(struct pmc_dev *pmcdev)
 {
 	mtl_d3_fixup();
-	pmc_core_send_ltr_ignore(pmcdev, 3, 0);
 
-	return pmc_core_resume_common(pmcdev);
+	return cnl_resume(pmcdev);
 }
 
 int mtl_core_init(struct pmc_dev *pmcdev)

base-commit: 9852d85ec9d492ebef56dc5f229416c925758edc
-- 
2.43.0

[PATCH V3 2/2] platform/x86/intel/pmc: Disable C1 auto-demotion during suspend

[David E. Box]

On some platforms, aggressive C1 auto-demotion may lead to failure to enter
the deepest C-state during suspend-to-idle, causing high power consumption.
To prevent this, disable C1 auto-demotion during suspend and re-enable on
resume.

Signed-off-by: David E. Box <david.e.box@linux.intel.com>
---
V3 - Use s2idle wrapper function suggested by Rafael
   - Use on_each_cpu() suggested by Ricardo

V2 - Remove #define DEBUG
   - Move refactor of cnl_resume() to separate patch
   - Use smp_call_function() to disable and restore C1_AUTO_DEMOTE
   - Add comment that the MSR is per core, not per package.
   - Add comment that the online cpu mask remains unchanged during
     suspend due to frozen userspace.

 drivers/platform/x86/intel/pmc/cnp.c | 53 ++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
index 513c02670c5a..3eaad2a7ebf4 100644
--- a/drivers/platform/x86/intel/pmc/cnp.c
+++ b/drivers/platform/x86/intel/pmc/cnp.c
@@ -8,6 +8,8 @@
  *
  */
 
+#include <linux/smp.h>
+#include <linux/suspend.h>
 #include "core.h"
 
 /* Cannon Lake: PGD PFET Enable Ack Status Register(s) bitmap */
@@ -206,8 +208,57 @@ const struct pmc_reg_map cnp_reg_map = {
 	.etr3_offset = ETR3_OFFSET,
 };
 
+
+/*
+ * Disable C1 auto-demotion
+ *
+ * Aggressive C1 auto-demotion may lead to failure to enter the deepest C-state
+ * during suspend-to-idle, causing high power consumption. To prevent this, we
+ * disable C1 auto-demotion during suspend and re-enable on resume.
+ *
+ * Note that, although MSR_PKG_CST_CONFIG_CONTROL has 'package' in its name, it
+ * is actually a per-core MSR on client platforms, affecting only a single CPU.
+ * Therefore, it must be configured on all online CPUs. The online cpu mask is
+ * unchanged during the phase of suspend/resume as user space is frozen.
+ */
+
+static DEFINE_PER_CPU(u64, pkg_cst_config);
+
+static void disable_c1_auto_demote(void *unused)
+{
+	int cpunum = smp_processor_id();
+	u64 val;
+
+	rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
+	per_cpu(pkg_cst_config, cpunum) = val;
+	val &= ~NHM_C1_AUTO_DEMOTE;
+	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
+
+	pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum, val);
+}
+
+static void restore_c1_auto_demote(void *unused)
+{
+	int cpunum = smp_processor_id();
+
+	wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, per_cpu(pkg_cst_config, cpunum));
+
+	pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum,
+		 per_cpu(pkg_cst_config, cpunum));
+}
+
+static void s2idle_cpu_quirk(smp_call_func_t func)
+{
+	if (pm_suspend_via_firmware())
+		return;
+
+	on_each_cpu(func, NULL, true);
+}
+
 void cnl_suspend(struct pmc_dev *pmcdev)
 {
+	s2idle_cpu_quirk(disable_c1_auto_demote);
+
 	/*
 	 * Due to a hardware limitation, the GBE LTR blocks PC10
 	 * when a cable is attached. To unblock PC10 during suspend,
@@ -218,6 +269,8 @@ void cnl_suspend(struct pmc_dev *pmcdev)
 
 int cnl_resume(struct pmc_dev *pmcdev)
 {
+	s2idle_cpu_quirk(restore_c1_auto_demote);
+
 	pmc_core_send_ltr_ignore(pmcdev, 3, 0);
 
 	return pmc_core_resume_common(pmcdev);
-- 
2.43.0

Re: [PATCH V3 1/2] platform/x86/intel/pmc: Refactor platform resume functions to use cnl_resume()

[Rafael J. Wysocki]

On Thu, Oct 17, 2024 at 11:04 PM David E. Box
<david.e.box@linux.intel.com> wrote:
>
> Several platform resume functions currently call pmc_core_send_ltr_ignore()
> and pmc_core_resume_common(), both of which are already called by
> cnl_resume(). Simplify the code by having these functions call cnl_resume()
> directly.
>
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> ---
> V3 - no change
>
> V2 - New patch. Split from V1

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

>
>  drivers/platform/x86/intel/pmc/arl.c | 3 +--
>  drivers/platform/x86/intel/pmc/lnl.c | 3 +--
>  drivers/platform/x86/intel/pmc/mtl.c | 3 +--
>  3 files changed, 3 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/platform/x86/intel/pmc/arl.c b/drivers/platform/x86/intel/pmc/arl.c
> index e10527c4e3e0..05dec4f5019f 100644
> --- a/drivers/platform/x86/intel/pmc/arl.c
> +++ b/drivers/platform/x86/intel/pmc/arl.c
> @@ -687,9 +687,8 @@ static void arl_d3_fixup(void)
>  static int arl_resume(struct pmc_dev *pmcdev)
>  {
>         arl_d3_fixup();
> -       pmc_core_send_ltr_ignore(pmcdev, 3, 0);
>
> -       return pmc_core_resume_common(pmcdev);
> +       return cnl_resume(pmcdev);
>  }
>
>  int arl_core_init(struct pmc_dev *pmcdev)
> diff --git a/drivers/platform/x86/intel/pmc/lnl.c b/drivers/platform/x86/intel/pmc/lnl.c
> index e7a8077d1a3e..be029f12cdf4 100644
> --- a/drivers/platform/x86/intel/pmc/lnl.c
> +++ b/drivers/platform/x86/intel/pmc/lnl.c
> @@ -546,9 +546,8 @@ static void lnl_d3_fixup(void)
>  static int lnl_resume(struct pmc_dev *pmcdev)
>  {
>         lnl_d3_fixup();
> -       pmc_core_send_ltr_ignore(pmcdev, 3, 0);
>
> -       return pmc_core_resume_common(pmcdev);
> +       return cnl_resume(pmcdev);
>  }
>
>  int lnl_core_init(struct pmc_dev *pmcdev)
> diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
> index 91f2fa728f5c..fc6a89b8979f 100644
> --- a/drivers/platform/x86/intel/pmc/mtl.c
> +++ b/drivers/platform/x86/intel/pmc/mtl.c
> @@ -988,9 +988,8 @@ static void mtl_d3_fixup(void)
>  static int mtl_resume(struct pmc_dev *pmcdev)
>  {
>         mtl_d3_fixup();
> -       pmc_core_send_ltr_ignore(pmcdev, 3, 0);
>
> -       return pmc_core_resume_common(pmcdev);
> +       return cnl_resume(pmcdev);
>  }
>
>  int mtl_core_init(struct pmc_dev *pmcdev)
>
> base-commit: 9852d85ec9d492ebef56dc5f229416c925758edc
> --
> 2.43.0
>
>

Re: [PATCH V3 2/2] platform/x86/intel/pmc: Disable C1 auto-demotion during suspend

[Rafael J. Wysocki]

On Thu, Oct 17, 2024 at 11:04 PM David E. Box
<david.e.box@linux.intel.com> wrote:
>
> On some platforms, aggressive C1 auto-demotion may lead to failure to enter
> the deepest C-state during suspend-to-idle, causing high power consumption.
> To prevent this, disable C1 auto-demotion during suspend and re-enable on
> resume.
>
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> ---
> V3 - Use s2idle wrapper function suggested by Rafael
>    - Use on_each_cpu() suggested by Ricardo

Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

> V2 - Remove #define DEBUG
>    - Move refactor of cnl_resume() to separate patch
>    - Use smp_call_function() to disable and restore C1_AUTO_DEMOTE
>    - Add comment that the MSR is per core, not per package.
>    - Add comment that the online cpu mask remains unchanged during
>      suspend due to frozen userspace.
>
>  drivers/platform/x86/intel/pmc/cnp.c | 53 ++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
>
> diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
> index 513c02670c5a..3eaad2a7ebf4 100644
> --- a/drivers/platform/x86/intel/pmc/cnp.c
> +++ b/drivers/platform/x86/intel/pmc/cnp.c
> @@ -8,6 +8,8 @@
>   *
>   */
>
> +#include <linux/smp.h>
> +#include <linux/suspend.h>
>  #include "core.h"
>
>  /* Cannon Lake: PGD PFET Enable Ack Status Register(s) bitmap */
> @@ -206,8 +208,57 @@ const struct pmc_reg_map cnp_reg_map = {
>         .etr3_offset = ETR3_OFFSET,
>  };
>
> +
> +/*
> + * Disable C1 auto-demotion
> + *
> + * Aggressive C1 auto-demotion may lead to failure to enter the deepest C-state
> + * during suspend-to-idle, causing high power consumption. To prevent this, we
> + * disable C1 auto-demotion during suspend and re-enable on resume.
> + *
> + * Note that, although MSR_PKG_CST_CONFIG_CONTROL has 'package' in its name, it
> + * is actually a per-core MSR on client platforms, affecting only a single CPU.
> + * Therefore, it must be configured on all online CPUs. The online cpu mask is
> + * unchanged during the phase of suspend/resume as user space is frozen.
> + */
> +
> +static DEFINE_PER_CPU(u64, pkg_cst_config);
> +
> +static void disable_c1_auto_demote(void *unused)
> +{
> +       int cpunum = smp_processor_id();
> +       u64 val;
> +
> +       rdmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
> +       per_cpu(pkg_cst_config, cpunum) = val;
> +       val &= ~NHM_C1_AUTO_DEMOTE;
> +       wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, val);
> +
> +       pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum, val);
> +}
> +
> +static void restore_c1_auto_demote(void *unused)
> +{
> +       int cpunum = smp_processor_id();
> +
> +       wrmsrl(MSR_PKG_CST_CONFIG_CONTROL, per_cpu(pkg_cst_config, cpunum));
> +
> +       pr_debug("%s: cpu:%d cst %llx\n", __func__, cpunum,
> +                per_cpu(pkg_cst_config, cpunum));
> +}
> +
> +static void s2idle_cpu_quirk(smp_call_func_t func)
> +{
> +       if (pm_suspend_via_firmware())
> +               return;
> +
> +       on_each_cpu(func, NULL, true);
> +}
> +
>  void cnl_suspend(struct pmc_dev *pmcdev)
>  {
> +       s2idle_cpu_quirk(disable_c1_auto_demote);
> +
>         /*
>          * Due to a hardware limitation, the GBE LTR blocks PC10
>          * when a cable is attached. To unblock PC10 during suspend,
> @@ -218,6 +269,8 @@ void cnl_suspend(struct pmc_dev *pmcdev)
>
>  int cnl_resume(struct pmc_dev *pmcdev)
>  {
> +       s2idle_cpu_quirk(restore_c1_auto_demote);
> +
>         pmc_core_send_ltr_ignore(pmcdev, 3, 0);
>
>         return pmc_core_resume_common(pmcdev);
> --
> 2.43.0
>
>

Re: [PATCH V3 1/2] platform/x86/intel/pmc: Refactor platform resume functions to use cnl_resume()

[Ilpo Järvinen]

On Thu, 17 Oct 2024 14:04:37 -0700, David E. Box wrote:

> Several platform resume functions currently call pmc_core_send_ltr_ignore()
> and pmc_core_resume_common(), both of which are already called by
> cnl_resume(). Simplify the code by having these functions call cnl_resume()
> directly.
> 
> 


Thank you for your contribution, it has been applied to my local
review-ilpo branch. Note it will show up in the public
platform-drivers-x86/review-ilpo branch only once I've pushed my
local branch there, which might take a while.

The list of commits applied:
[1/2] platform/x86/intel/pmc: Refactor platform resume functions to use cnl_resume()
      commit: 9fe43c8020a60b9c9ff44c4a9914e7e7df63084e
[2/2] platform/x86/intel/pmc: Disable C1 auto-demotion during suspend
      commit: 7a797cc9f80915cc5f1a5aee46d14880eb444644

--
 i.