linux-pm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Perry Yuan <perry.yuan@amd.com>
To: <rafael.j.wysocki@intel.com>, <Mario.Limonciello@amd.com>,
	<viresh.kumar@linaro.org>, <gautham.shenoy@amd.com>,
	<Borislav.Petkov@amd.com>, <Ray.Huang@amd.com>,
	<Alexander.Deucher@amd.com>
Cc: <Xinmei.Huang@amd.com>, <oleksandr@natalenko.name>,
	<Xiaojian.Du@amd.com>, <Li.Meng@amd.com>,
	<linux-pm@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH v11 6/8] cpufreq: amd-pstate: get transition delay and latency value from ACPI tables
Date: Tue, 23 Apr 2024 15:58:22 +0800	[thread overview]
Message-ID: <81aafa46533637984cc9c80f90faf5498a7308c9.1713858800.git.perry.yuan@amd.com> (raw)
In-Reply-To: <cover.1713858800.git.perry.yuan@amd.com>

Make pstate driver initially retrieve the P-state transition delay and
latency values from the BIOS ACPI tables which has more reasonable
delay and latency values according to the platform design and
requirements.

Previously there values were hardcoded at specific value which may
have conflicted with platform and it might not reflect the most
accurate or optimized setting for the processor.

[054h 0084   8]                Preserve Mask : FFFFFFFF00000000
[05Ch 0092   8]                   Write Mask : 0000000000000001
[064h 0100   4]              Command Latency : 00000FA0
[068h 0104   4]          Maximum Access Rate : 0000EA60
[06Ch 0108   2]      Minimum Turnaround Time : 0000

Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Tested-by: Dhananjay Ugwekar <Dhananjay.Ugwekar@amd.com>
Signed-off-by: Perry Yuan <perry.yuan@amd.com>
Acked-by: Huang Rui <ray.huang@amd.com>
---
 drivers/cpufreq/amd-pstate.c | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 960fead0b83e..510b5aec42ea 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -756,6 +756,36 @@ static void amd_pstate_update_limits(unsigned int cpu)
 	mutex_unlock(&amd_pstate_driver_lock);
 }
 
+/**
+ * Get pstate transition delay time from ACPI tables that firmware set
+ * instead of using hardcode value directly.
+ */
+static u32 amd_pstate_get_transition_delay_us(unsigned int cpu)
+{
+	u32 transition_delay_ns;
+
+	transition_delay_ns = cppc_get_transition_latency(cpu);
+	if (transition_delay_ns == CPUFREQ_ETERNAL)
+		return AMD_PSTATE_TRANSITION_DELAY;
+
+	return transition_delay_ns / NSEC_PER_USEC;
+}
+
+/**
+ * Get pstate transition latency value from ACPI tables that firmware
+ * set instead of using hardcode value directly.
+ */
+static u32 amd_pstate_get_transition_latency(unsigned int cpu)
+{
+	u32 transition_latency;
+
+	transition_latency = cppc_get_transition_latency(cpu);
+	if (transition_latency  == CPUFREQ_ETERNAL)
+		return AMD_PSTATE_TRANSITION_LATENCY;
+
+	return transition_latency;
+}
+
 /**
  * amd_pstate_init_freq: Initialize the max_freq, min_freq,
  *                       nominal_freq and lowest_nonlinear_freq for
@@ -848,8 +878,8 @@ static int amd_pstate_cpu_init(struct cpufreq_policy *policy)
 		goto free_cpudata1;
 	}
 
-	policy->cpuinfo.transition_latency = AMD_PSTATE_TRANSITION_LATENCY;
-	policy->transition_delay_us = AMD_PSTATE_TRANSITION_DELAY;
+	policy->cpuinfo.transition_latency = amd_pstate_get_transition_latency(policy->cpu);
+	policy->transition_delay_us = amd_pstate_get_transition_delay_us(policy->cpu);
 
 	policy->min = min_freq;
 	policy->max = max_freq;
-- 
2.34.1


  parent reply	other threads:[~2024-04-23  7:59 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-04-23  7:58 [PATCH v11 0/8] AMD Pstate Fixes And Enhancements Perry Yuan
2024-04-23  7:58 ` [PATCH v11 1/8] cpufreq: amd-pstate: Document *_limit_* fields in struct amd_cpudata Perry Yuan
2024-04-23 10:22   ` Huang Rui
2024-04-24  3:04     ` Yuan, Perry
2024-04-23  7:58 ` [PATCH v11 2/8] cpufreq: amd-pstate: Document the units for freq variables in amd_cpudata Perry Yuan
2024-04-23  7:58 ` [PATCH v11 3/8] cpufreq: amd-pstate: Unify computation of {max,min,nominal,lowest_nonlinear}_freq Perry Yuan
2024-04-23  7:58 ` [PATCH v11 4/8] cpufreq: amd-pstate: Remove amd_get_{min,max,nominal,lowest_nonlinear}_freq() Perry Yuan
2024-04-23  7:58 ` [PATCH v11 5/8] cpufreq: amd-pstate: Bail out if min/max/nominal_freq is 0 Perry Yuan
2024-04-23  7:58 ` Perry Yuan [this message]
2024-04-23  7:58 ` [PATCH v11 7/8] cppc_acpi: print error message if CPPC is unsupported Perry Yuan
2024-04-23  7:58 ` [PATCH v11 8/8] cpufreq: amd-pstate: Add quirk for the pstate CPPC capabilities missing Perry Yuan
2024-04-23 10:39 ` [PATCH v11 0/8] AMD Pstate Fixes And Enhancements Huang Rui

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=81aafa46533637984cc9c80f90faf5498a7308c9.1713858800.git.perry.yuan@amd.com \
    --to=perry.yuan@amd.com \
    --cc=Alexander.Deucher@amd.com \
    --cc=Borislav.Petkov@amd.com \
    --cc=Li.Meng@amd.com \
    --cc=Mario.Limonciello@amd.com \
    --cc=Ray.Huang@amd.com \
    --cc=Xiaojian.Du@amd.com \
    --cc=Xinmei.Huang@amd.com \
    --cc=gautham.shenoy@amd.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=oleksandr@natalenko.name \
    --cc=rafael.j.wysocki@intel.com \
    --cc=viresh.kumar@linaro.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).