| Message ID | 20210909034802.1708-1-dsmythies@telus.net |
|---|---|
| State | New |
| Headers | show |
| Series | cpufreq: intel_pstate: Override parameters if HWP forced by BIOS | expand |
On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> wrote: > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote: > > If HWP has been already been enabled by BIOS, it may be > > necessary to override some kernel command line parameters. > > Once it has been enabled it requires a reset to be disabled. > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net> > > --- > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------ > > 1 file changed, 16 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/cpufreq/intel_pstate.c > > b/drivers/cpufreq/intel_pstate.c > > index bb4549959b11..073bae5d4498 100644 > > --- a/drivers/cpufreq/intel_pstate.c > > +++ b/drivers/cpufreq/intel_pstate.c > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void) > > */ > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || > > intel_pstate_hwp_is_enabled()) { > > - hwp_active++; > > + hwp_active = 1; > Why this change? I think hwp_active can be changed to bool and then it would make sense to update this line. > > hwp_mode_bdw = id->driver_data; > > intel_pstate.attr = hwp_cpufreq_attrs; > > intel_cpufreq.attr = hwp_cpufreq_attrs; > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init); > > > > static int __init intel_pstate_setup(char *str) > > { > > + /* > > + * If BIOS is forcing HWP, then parameter > > + * overrides might be needed. Only print > > + * the message once, and regardless of > > + * any overrides. > > + */ > > + if(!hwp_active > This part of code is from early_param, Is it possible that > hwp_active is not 0? Well, it wouldn't matter even if it were nonzero. This check is just pointless anyway. > > && boot_cpu_has(X86_FEATURE_HWP)) > > + if(intel_pstate_hwp_is_enabled()){ This should be if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) { > > + pr_info("HWP enabled by BIOS\n"); > > + hwp_active = 1; > > + } > > if (!str) > > return -EINVAL; > > > > - if (!strcmp(str, "disable")) > > + if (!strcmp(str, "disable") && !hwp_active) > > no_load = 1; > > - else if (!strcmp(str, "active")) > > + if (!strcmp(str, "active")) > > default_driver = &intel_pstate; > > - else if (!strcmp(str, "passive")) > > + if (!strcmp(str, "passive")) > > default_driver = &intel_cpufreq; > > Why "else if" changed to "if" ? > > > - > > - if (!strcmp(str, "no_hwp")) { > > + if (!strcmp(str, "no_hwp") && !hwp_active) { > > pr_info("HWP disabled\n"); > > no_hwp = 1; > > } >
On Wed, Sep 8, 2021 at 11:33 PM Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> wrote: > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote: > > If HWP has been already been enabled by BIOS, it may be > > necessary to override some kernel command line parameters. > > Once it has been enabled it requires a reset to be disabled. > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net> > > --- > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------ > > 1 file changed, 16 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/cpufreq/intel_pstate.c > > b/drivers/cpufreq/intel_pstate.c > > index bb4549959b11..073bae5d4498 100644 > > --- a/drivers/cpufreq/intel_pstate.c > > +++ b/drivers/cpufreq/intel_pstate.c > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void) > > */ > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || > > intel_pstate_hwp_is_enabled()) { > > - hwp_active++; > > + hwp_active = 1; > Why this change? It was just to keep it at 1, but I agree not absolutely needed. > > > hwp_mode_bdw = id->driver_data; > > intel_pstate.attr = hwp_cpufreq_attrs; > > intel_cpufreq.attr = hwp_cpufreq_attrs; > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init); > > > > static int __init intel_pstate_setup(char *str) > > { > > + /* > > + * If BIOS is forcing HWP, then parameter > > + * overrides might be needed. Only print > > + * the message once, and regardless of > > + * any overrides. > > + */ > > + if(!hwp_active > This part of code is from early_param, Is it possible that > hwp_active is not 0? Not at this point, in any testing I did. But I do not know the authoritative answer to your question. > > > && boot_cpu_has(X86_FEATURE_HWP)) > > + if(intel_pstate_hwp_is_enabled()){ > > + pr_info("HWP enabled by BIOS\n"); > > + hwp_active = 1; > > + } > > if (!str) > > return -EINVAL; > > > > - if (!strcmp(str, "disable")) > > + if (!strcmp(str, "disable") && !hwp_active) > > no_load = 1; > > - else if (!strcmp(str, "active")) > > + if (!strcmp(str, "active")) > > default_driver = &intel_pstate; > > - else if (!strcmp(str, "passive")) > > + if (!strcmp(str, "passive")) > > default_driver = &intel_cpufreq; > > Why "else if" changed to "if" ? Because it doesn't matter anyway and I would have had to figure out another qualifier. This way, and given that this executes once per intel_pstate command line parameter, the code executes the way it used to, overall. > > > Thanks, > Srinivas > > > - > > - if (!strcmp(str, "no_hwp")) { > > + if (!strcmp(str, "no_hwp") && !hwp_active) { > > pr_info("HWP disabled\n"); > > no_hwp = 1; > > } > >
On Thu, Sep 9, 2021 at 3:20 PM Doug Smythies <dsmythies@telus.net> wrote: > > On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > > > > On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada > > <srinivas.pandruvada@linux.intel.com> wrote: > > > > > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote: > > > > If HWP has been already been enabled by BIOS, it may be > > > > necessary to override some kernel command line parameters. > > > > Once it has been enabled it requires a reset to be disabled. > > > > > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net> > > > > --- > > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------ > > > > 1 file changed, 16 insertions(+), 6 deletions(-) > > > > > > > > diff --git a/drivers/cpufreq/intel_pstate.c > > > > b/drivers/cpufreq/intel_pstate.c > > > > index bb4549959b11..073bae5d4498 100644 > > > > --- a/drivers/cpufreq/intel_pstate.c > > > > +++ b/drivers/cpufreq/intel_pstate.c > > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void) > > > > */ > > > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || > > > > intel_pstate_hwp_is_enabled()) { > > > > - hwp_active++; > > > > + hwp_active = 1; > > > Why this change? > > > > I think hwp_active can be changed to bool and then it would make sense > > to update this line. > > > > > > hwp_mode_bdw = id->driver_data; > > > > intel_pstate.attr = hwp_cpufreq_attrs; > > > > intel_cpufreq.attr = hwp_cpufreq_attrs; > > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init); > > > > > > > > static int __init intel_pstate_setup(char *str) > > > > { > > > > + /* > > > > + * If BIOS is forcing HWP, then parameter > > > > + * overrides might be needed. Only print > > > > + * the message once, and regardless of > > > > + * any overrides. > > > > + */ > > > > + if(!hwp_active > > > This part of code is from early_param, Is it possible that > > > hwp_active is not 0? > > > > Well, it wouldn't matter even if it were nonzero. This check is just > > pointless anyway. > > > > > > && boot_cpu_has(X86_FEATURE_HWP)) > > > > + if(intel_pstate_hwp_is_enabled()){ > > > > This should be > > > > if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) { > > Disagree. > This routine gets executed once per intel_pstate related grub command > line entry. The purpose of the "if(!hwp_active" part is to prevent the > printing of the message to the logs multiple times. Ah OK. Fair enough. You can do all of the checks in one conditional, though. They will be processed left-to-right anyway. But then it would be good to avoid calling intel_pstate_hwp_is_enabled() multiple times if it returns false. And having said all that I'm not sure why you are trying to make no_hwp depend on !hwp_active? I will not be taken into account anyway if intel_pstate_hwp_is_enabled() returns 'true'? So if no_hwp is covered regardless, you may move the intel_pstate_hwp_is_enabled() inside the no_load conditional. Alternatively, and I would do that, intel_pstate_hwp_is_enabled() could be evaluated earlier in intel_pstate_init() and if it returned 'true', both no_load and no_hwp would be disregarded.
On Thu, Sep 9, 2021 at 10:22 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > On Thu, Sep 9, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote: > > On Thu, Sep 9, 2021 at 3:20 PM Doug Smythies <dsmythies@telus.net> wrote: > > > On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > > > > On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada > > > > <srinivas.pandruvada@linux.intel.com> wrote: > > > > > > > > > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote: > > > > > > If HWP has been already been enabled by BIOS, it may be > > > > > > necessary to override some kernel command line parameters. > > > > > > Once it has been enabled it requires a reset to be disabled. > > > > > > > > > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net> > > > > > > --- > > > > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------ > > > > > > 1 file changed, 16 insertions(+), 6 deletions(-) > > > > > > > > > > > > diff --git a/drivers/cpufreq/intel_pstate.c > > > > > > b/drivers/cpufreq/intel_pstate.c > > > > > > index bb4549959b11..073bae5d4498 100644 > > > > > > --- a/drivers/cpufreq/intel_pstate.c > > > > > > +++ b/drivers/cpufreq/intel_pstate.c > > > > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void) > > > > > > */ > > > > > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || > > > > > > intel_pstate_hwp_is_enabled()) { > > > > > > - hwp_active++; > > > > > > + hwp_active = 1; > > > > > Why this change? > > > > > > > > I think hwp_active can be changed to bool and then it would make sense > > > > to update this line. > > > > > > > > > > hwp_mode_bdw = id->driver_data; > > > > > > intel_pstate.attr = hwp_cpufreq_attrs; > > > > > > intel_cpufreq.attr = hwp_cpufreq_attrs; > > > > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init); > > > > > > > > > > > > static int __init intel_pstate_setup(char *str) > > > > > > { > > > > > > + /* > > > > > > + * If BIOS is forcing HWP, then parameter > > > > > > + * overrides might be needed. Only print > > > > > > + * the message once, and regardless of > > > > > > + * any overrides. > > > > > > + */ > > > > > > + if(!hwp_active > > > > > This part of code is from early_param, Is it possible that > > > > > hwp_active is not 0? > > > > > > > > Well, it wouldn't matter even if it were nonzero. This check is just > > > > pointless anyway. > > > > > > > > > > && boot_cpu_has(X86_FEATURE_HWP)) > > > > > > + if(intel_pstate_hwp_is_enabled()){ > > > > > > > > This should be > > > > > > > > if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) { > > > > > > Disagree. > > > This routine gets executed once per intel_pstate related grub command > > > line entry. The purpose of the "if(!hwp_active" part is to prevent the > > > printing of the message to the logs multiple times. > > > > Ah OK. Fair enough. > > > > You can do all of the checks in one conditional, though. They will be > > processed left-to-right anyway. > > > > But then it would be good to avoid calling > > intel_pstate_hwp_is_enabled() multiple times if it returns false. > > > > And having said all that I'm not sure why you are trying to make > > no_hwp depend on !hwp_active? I will not be taken into account anyway > > if intel_pstate_hwp_is_enabled() returns 'true'? > > > > So if no_hwp is covered regardless, you may move the > > intel_pstate_hwp_is_enabled() inside the no_load conditional. > > > > Alternatively, and I would do that, intel_pstate_hwp_is_enabled() > > could be evaluated earlier in intel_pstate_init() and if it returned > > 'true', both no_load and no_hwp would be disregarded. > > Something like the attached, for the record. O.K. and Thanks. I was trying to avoid this line getting into the log: [ 0.000000] intel_pstate: HWP disabled only to overridden later by, now, these lines: [ 0.373742] intel_pstate: HWP enabled by BIOS [ 0.374177] intel_pstate: Intel P-state driver initializing [ 0.375097] intel_pstate: HWP enabled Let me see if I can go with your suggestion and get to what I had hoped to get in the logs. By the way, my current command line options are: [ 0.000000] Command line: BOOT_IMAGE=/boot/vmlinuz-5.14.0-ipstate9 root=UUID=0ac356c1-caa9-4c2e-8229-4408bd998dbd ro ipv6.disable=1 consoleblank=314 intel_pstate=force intel_pstate=active intel_pstate=no_hwp msr.allow_writes=on cpuidle.governor=teo ... Doug
On Thu, Sep 9, 2021 at 7:53 AM Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> wrote: > On Thu, 2021-09-09 at 06:30 -0700, Doug Smythies wrote: > > On Wed, Sep 8, 2021 at 11:33 PM Srinivas Pandruvada > > <srinivas.pandruvada@linux.intel.com> wrote: > > > > > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote: > > > > If HWP has been already been enabled by BIOS, it may be > > > > necessary to override some kernel command line parameters. > > > > Once it has been enabled it requires a reset to be disabled. > > > > > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net> > > > > --- > > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------ > > > > 1 file changed, 16 insertions(+), 6 deletions(-) > > > > > > > > diff --git a/drivers/cpufreq/intel_pstate.c > > > > b/drivers/cpufreq/intel_pstate.c > > > > index bb4549959b11..073bae5d4498 100644 > > > > --- a/drivers/cpufreq/intel_pstate.c > > > > +++ b/drivers/cpufreq/intel_pstate.c > > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void) > > > > */ > > > > if ((!no_hwp && > > > > boot_cpu_has(X86_FEATURE_HWP_EPP)) || > > > > intel_pstate_hwp_is_enabled()) { > > > > - hwp_active++; > > > > + hwp_active = 1; > > > Why this change? > > > > It was just to keep it at 1, but I agree not absolutely needed. > > > > > > > > > hwp_mode_bdw = id->driver_data; > > > > intel_pstate.attr = hwp_cpufreq_attrs; > > > > intel_cpufreq.attr = hwp_cpufreq_attrs; > > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init); > > > > > > > > static int __init intel_pstate_setup(char *str) > > > > { > > > > + /* > > > > + * If BIOS is forcing HWP, then parameter > > > > + * overrides might be needed. Only print > > > > + * the message once, and regardless of > > > > + * any overrides. > > > > + */ > > > > + if(!hwp_active > > > This part of code is from early_param, Is it possible that > > > hwp_active is not 0? > > > > Not at this point, in any testing I did. > > But I do not know the authoritative answer > > to your question. > > > But as you explained you want to prevent repeated print of > "HWP enabled by BIOS". So you need this. > > > > > > > > && boot_cpu_has(X86_FEATURE_HWP)) > > > > + if(intel_pstate_hwp_is_enabled()){ > > > > + pr_info("HWP enabled by BIOS\n"); > > > > + hwp_active = 1; > > > > + } > > > > if (!str) > > > > return -EINVAL; > > > > > > > > - if (!strcmp(str, "disable")) > > > > + if (!strcmp(str, "disable") && !hwp_active) > > > > no_load = 1; > > > > - else if (!strcmp(str, "active")) > > > > + if (!strcmp(str, "active")) > > > > default_driver = &intel_pstate; > > > > - else if (!strcmp(str, "passive")) > > > > + if (!strcmp(str, "passive")) > > > > default_driver = &intel_cpufreq; > > > > > > Why "else if" changed to "if" ? > > > > Because it doesn't matter anyway and I would > > have had to figure out another qualifier. > > This way, and given that this executes once per > > intel_pstate command line parameter, the code > > executes the way it used to, overall. > If someone specified intel_pstate=active, it will also compare with > "passive" with this change. Disagree. As far as I can tell, and I tested, it works as expected. ... Doug > > > > - > > > > - if (!strcmp(str, "no_hwp")) { > > > > + if (!strcmp(str, "no_hwp") && !hwp_active) { > > > > pr_info("HWP disabled\n"); > > > > no_hwp = 1; > > > > } > > > > > > > >
On Fri, Sep 10, 2021 at 5:14 AM Doug Smythies <dsmythies@telus.net> wrote: > > On Thu, Sep 9, 2021 at 10:22 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > > On Thu, Sep 9, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote: > > > On Thu, Sep 9, 2021 at 3:20 PM Doug Smythies <dsmythies@telus.net> wrote: > > > > On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > > > > > On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada > > > > > <srinivas.pandruvada@linux.intel.com> wrote: > > > > > > > > > > > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote: > > > > > > > If HWP has been already been enabled by BIOS, it may be > > > > > > > necessary to override some kernel command line parameters. > > > > > > > Once it has been enabled it requires a reset to be disabled. > > > > > > > > > > > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net> > > > > > > > --- > > > > > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------ > > > > > > > 1 file changed, 16 insertions(+), 6 deletions(-) > > > > > > > > > > > > > > diff --git a/drivers/cpufreq/intel_pstate.c > > > > > > > b/drivers/cpufreq/intel_pstate.c > > > > > > > index bb4549959b11..073bae5d4498 100644 > > > > > > > --- a/drivers/cpufreq/intel_pstate.c > > > > > > > +++ b/drivers/cpufreq/intel_pstate.c > > > > > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void) > > > > > > > */ > > > > > > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || > > > > > > > intel_pstate_hwp_is_enabled()) { > > > > > > > - hwp_active++; > > > > > > > + hwp_active = 1; > > > > > > Why this change? > > > > > > > > > > I think hwp_active can be changed to bool and then it would make sense > > > > > to update this line. > > > > > > > > > > > > hwp_mode_bdw = id->driver_data; > > > > > > > intel_pstate.attr = hwp_cpufreq_attrs; > > > > > > > intel_cpufreq.attr = hwp_cpufreq_attrs; > > > > > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init); > > > > > > > > > > > > > > static int __init intel_pstate_setup(char *str) > > > > > > > { > > > > > > > + /* > > > > > > > + * If BIOS is forcing HWP, then parameter > > > > > > > + * overrides might be needed. Only print > > > > > > > + * the message once, and regardless of > > > > > > > + * any overrides. > > > > > > > + */ > > > > > > > + if(!hwp_active > > > > > > This part of code is from early_param, Is it possible that > > > > > > hwp_active is not 0? > > > > > > > > > > Well, it wouldn't matter even if it were nonzero. This check is just > > > > > pointless anyway. > > > > > > > > > > > > && boot_cpu_has(X86_FEATURE_HWP)) > > > > > > > + if(intel_pstate_hwp_is_enabled()){ > > > > > > > > > > This should be > > > > > > > > > > if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) { > > > > > > > > Disagree. > > > > This routine gets executed once per intel_pstate related grub command > > > > line entry. The purpose of the "if(!hwp_active" part is to prevent the > > > > printing of the message to the logs multiple times. > > > > > > Ah OK. Fair enough. > > > > > > You can do all of the checks in one conditional, though. They will be > > > processed left-to-right anyway. > > > > > > But then it would be good to avoid calling > > > intel_pstate_hwp_is_enabled() multiple times if it returns false. > > > > > > And having said all that I'm not sure why you are trying to make > > > no_hwp depend on !hwp_active? I will not be taken into account anyway > > > if intel_pstate_hwp_is_enabled() returns 'true'? > > > > > > So if no_hwp is covered regardless, you may move the > > > intel_pstate_hwp_is_enabled() inside the no_load conditional. > > > > > > Alternatively, and I would do that, intel_pstate_hwp_is_enabled() > > > could be evaluated earlier in intel_pstate_init() and if it returned > > > 'true', both no_load and no_hwp would be disregarded. > > > > Something like the attached, for the record. > > O.K. and Thanks. > I was trying to avoid this line getting into the log: > > [ 0.000000] intel_pstate: HWP disabled > > only to overridden later by, now, these lines: > > [ 0.373742] intel_pstate: HWP enabled by BIOS > [ 0.374177] intel_pstate: Intel P-state driver initializing > [ 0.375097] intel_pstate: HWP enabled > > Let me see if I can go with your suggestion and get to > what I had hoped to get in the logs. It would be sufficient to put the "disabled" printk() after the "no_hwp" if () statement in intel_pstate_init(). See attached. BTW, I've changed the message to "HWP not enabled", because that's what really happens to be precise. --- drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) Index: linux-pm/drivers/cpufreq/intel_pstate.c =================================================================== --- linux-pm.orig/drivers/cpufreq/intel_pstate.c +++ linux-pm/drivers/cpufreq/intel_pstate.c @@ -3205,11 +3205,15 @@ static int __init intel_pstate_init(void if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) return -ENODEV; - if (no_load) - return -ENODEV; - id = x86_match_cpu(hwp_support_ids); if (id) { + bool hwp_forced = intel_pstate_hwp_is_enabled(); + + if (hwp_forced) + pr_info("HWP enabled by BIOS\n"); + else if (no_load) + return -ENODEV; + copy_cpu_funcs(&core_funcs); /* * Avoid enabling HWP for processors without EPP support, @@ -3219,8 +3223,7 @@ static int __init intel_pstate_init(void * If HWP is enabled already, though, there is no choice but to * deal with it. */ - if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || - intel_pstate_hwp_is_enabled()) { + if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || hwp_forced) { hwp_active++; hwp_mode_bdw = id->driver_data; intel_pstate.attr = hwp_cpufreq_attrs; @@ -3235,7 +3238,11 @@ static int __init intel_pstate_init(void goto hwp_cpu_matched; } + pr_info("HWP not enabled\n"); } else { + if (no_load) + return -ENODEV; + id = x86_match_cpu(intel_pstate_cpu_ids); if (!id) { pr_info("CPU model not supported\n"); @@ -3314,10 +3321,9 @@ static int __init intel_pstate_setup(cha else if (!strcmp(str, "passive")) default_driver = &intel_cpufreq; - if (!strcmp(str, "no_hwp")) { - pr_info("HWP disabled\n"); + if (!strcmp(str, "no_hwp")) no_hwp = 1; - } + if (!strcmp(str, "force")) force_load = 1; if (!strcmp(str, "hwp_only"))
On Fri, Sep 10, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > On Fri, Sep 10, 2021 at 5:14 AM Doug Smythies <dsmythies@telus.net> wrote: > > On Thu, Sep 9, 2021 at 10:22 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > > > On Thu, Sep 9, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote: > > > > On Thu, Sep 9, 2021 at 3:20 PM Doug Smythies <dsmythies@telus.net> wrote: > > > > > On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > > > > > > On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada > > > > > > <srinivas.pandruvada@linux.intel.com> wrote: > > > > > > > > > > > > > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote: > > > > > > > > If HWP has been already been enabled by BIOS, it may be > > > > > > > > necessary to override some kernel command line parameters. > > > > > > > > Once it has been enabled it requires a reset to be disabled. > > > > > > > > > > > > > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net> > > > > > > > > --- > > > > > > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------ > > > > > > > > 1 file changed, 16 insertions(+), 6 deletions(-) > > > > > > > > > > > > > > > > diff --git a/drivers/cpufreq/intel_pstate.c > > > > > > > > b/drivers/cpufreq/intel_pstate.c > > > > > > > > index bb4549959b11..073bae5d4498 100644 > > > > > > > > --- a/drivers/cpufreq/intel_pstate.c > > > > > > > > +++ b/drivers/cpufreq/intel_pstate.c > > > > > > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void) > > > > > > > > */ > > > > > > > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || > > > > > > > > intel_pstate_hwp_is_enabled()) { > > > > > > > > - hwp_active++; > > > > > > > > + hwp_active = 1; > > > > > > > Why this change? > > > > > > > > > > > > I think hwp_active can be changed to bool and then it would make sense > > > > > > to update this line. > > > > > > > > > > > > > > hwp_mode_bdw = id->driver_data; > > > > > > > > intel_pstate.attr = hwp_cpufreq_attrs; > > > > > > > > intel_cpufreq.attr = hwp_cpufreq_attrs; > > > > > > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init); > > > > > > > > > > > > > > > > static int __init intel_pstate_setup(char *str) > > > > > > > > { > > > > > > > > + /* > > > > > > > > + * If BIOS is forcing HWP, then parameter > > > > > > > > + * overrides might be needed. Only print > > > > > > > > + * the message once, and regardless of > > > > > > > > + * any overrides. > > > > > > > > + */ > > > > > > > > + if(!hwp_active > > > > > > > This part of code is from early_param, Is it possible that > > > > > > > hwp_active is not 0? > > > > > > > > > > > > Well, it wouldn't matter even if it were nonzero. This check is just > > > > > > pointless anyway. > > > > > > > > > > > > > > && boot_cpu_has(X86_FEATURE_HWP)) > > > > > > > > + if(intel_pstate_hwp_is_enabled()){ > > > > > > > > > > > > This should be > > > > > > > > > > > > if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) { > > > > > > > > > > Disagree. > > > > > This routine gets executed once per intel_pstate related grub command > > > > > line entry. The purpose of the "if(!hwp_active" part is to prevent the > > > > > printing of the message to the logs multiple times. > > > > > > > > Ah OK. Fair enough. > > > > > > > > You can do all of the checks in one conditional, though. They will be > > > > processed left-to-right anyway. > > > > > > > > But then it would be good to avoid calling > > > > intel_pstate_hwp_is_enabled() multiple times if it returns false. > > > > > > > > And having said all that I'm not sure why you are trying to make > > > > no_hwp depend on !hwp_active? I will not be taken into account anyway > > > > if intel_pstate_hwp_is_enabled() returns 'true'? > > > > > > > > So if no_hwp is covered regardless, you may move the > > > > intel_pstate_hwp_is_enabled() inside the no_load conditional. > > > > > > > > Alternatively, and I would do that, intel_pstate_hwp_is_enabled() > > > > could be evaluated earlier in intel_pstate_init() and if it returned > > > > 'true', both no_load and no_hwp would be disregarded. > > > > > > Something like the attached, for the record. > > > > O.K. and Thanks. > > I was trying to avoid this line getting into the log: > > > > [ 0.000000] intel_pstate: HWP disabled > > > > only to overridden later by, now, these lines: > > > > [ 0.373742] intel_pstate: HWP enabled by BIOS > > [ 0.374177] intel_pstate: Intel P-state driver initializing > > [ 0.375097] intel_pstate: HWP enabled > > > > Let me see if I can go with your suggestion and get to > > what I had hoped to get in the logs. > > It would be sufficient to put the "disabled" printk() after the > "no_hwp" if () statement in intel_pstate_init(). See attached. Agreed, thanks. Yes, I was thinking similar. > BTW, I've changed the message to "HWP not enabled", because that's > what really happens to be precise. Agreed. Good idea. Give me a fews days to create and test a formal patch. I currently have limited access to a computer that doesn't force HWP via BIOS. ... Doug
On Fri, Sep 10, 2021 at 5:35 PM Doug Smythies <dsmythies@telus.net> wrote: > > On Fri, Sep 10, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > > On Fri, Sep 10, 2021 at 5:14 AM Doug Smythies <dsmythies@telus.net> wrote: > > > On Thu, Sep 9, 2021 at 10:22 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > > > > On Thu, Sep 9, 2021 at 6:12 PM Rafael J. Wysocki <rafael@kernel.org> wrote: > > > > > On Thu, Sep 9, 2021 at 3:20 PM Doug Smythies <dsmythies@telus.net> wrote: > > > > > > On Thu, Sep 9, 2021 at 4:18 AM Rafael J. Wysocki <rafael@kernel.org> wrote: > > > > > > > On Thu, Sep 9, 2021 at 8:52 AM Srinivas Pandruvada > > > > > > > <srinivas.pandruvada@linux.intel.com> wrote: > > > > > > > > > > > > > > > > On Wed, 2021-09-08 at 20:48 -0700, Doug Smythies wrote: > > > > > > > > > If HWP has been already been enabled by BIOS, it may be > > > > > > > > > necessary to override some kernel command line parameters. > > > > > > > > > Once it has been enabled it requires a reset to be disabled. > > > > > > > > > > > > > > > > > > Signed-off-by: Doug Smythies <dsmythies@telus.net> > > > > > > > > > --- > > > > > > > > > drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------ > > > > > > > > > 1 file changed, 16 insertions(+), 6 deletions(-) > > > > > > > > > > > > > > > > > > diff --git a/drivers/cpufreq/intel_pstate.c > > > > > > > > > b/drivers/cpufreq/intel_pstate.c > > > > > > > > > index bb4549959b11..073bae5d4498 100644 > > > > > > > > > --- a/drivers/cpufreq/intel_pstate.c > > > > > > > > > +++ b/drivers/cpufreq/intel_pstate.c > > > > > > > > > @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void) > > > > > > > > > */ > > > > > > > > > if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || > > > > > > > > > intel_pstate_hwp_is_enabled()) { > > > > > > > > > - hwp_active++; > > > > > > > > > + hwp_active = 1; > > > > > > > > Why this change? > > > > > > > > > > > > > > I think hwp_active can be changed to bool and then it would make sense > > > > > > > to update this line. > > > > > > > > > > > > > > > > hwp_mode_bdw = id->driver_data; > > > > > > > > > intel_pstate.attr = hwp_cpufreq_attrs; > > > > > > > > > intel_cpufreq.attr = hwp_cpufreq_attrs; > > > > > > > > > @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init); > > > > > > > > > > > > > > > > > > static int __init intel_pstate_setup(char *str) > > > > > > > > > { > > > > > > > > > + /* > > > > > > > > > + * If BIOS is forcing HWP, then parameter > > > > > > > > > + * overrides might be needed. Only print > > > > > > > > > + * the message once, and regardless of > > > > > > > > > + * any overrides. > > > > > > > > > + */ > > > > > > > > > + if(!hwp_active > > > > > > > > This part of code is from early_param, Is it possible that > > > > > > > > hwp_active is not 0? > > > > > > > > > > > > > > Well, it wouldn't matter even if it were nonzero. This check is just > > > > > > > pointless anyway. > > > > > > > > > > > > > > > > && boot_cpu_has(X86_FEATURE_HWP)) > > > > > > > > > + if(intel_pstate_hwp_is_enabled()){ > > > > > > > > > > > > > > This should be > > > > > > > > > > > > > > if (boot_cpu_has(X86_FEATURE_HWP) && intel_pstate_hwp_is_enabled()) { > > > > > > > > > > > > Disagree. > > > > > > This routine gets executed once per intel_pstate related grub command > > > > > > line entry. The purpose of the "if(!hwp_active" part is to prevent the > > > > > > printing of the message to the logs multiple times. > > > > > > > > > > Ah OK. Fair enough. > > > > > > > > > > You can do all of the checks in one conditional, though. They will be > > > > > processed left-to-right anyway. > > > > > > > > > > But then it would be good to avoid calling > > > > > intel_pstate_hwp_is_enabled() multiple times if it returns false. > > > > > > > > > > And having said all that I'm not sure why you are trying to make > > > > > no_hwp depend on !hwp_active? I will not be taken into account anyway > > > > > if intel_pstate_hwp_is_enabled() returns 'true'? > > > > > > > > > > So if no_hwp is covered regardless, you may move the > > > > > intel_pstate_hwp_is_enabled() inside the no_load conditional. > > > > > > > > > > Alternatively, and I would do that, intel_pstate_hwp_is_enabled() > > > > > could be evaluated earlier in intel_pstate_init() and if it returned > > > > > 'true', both no_load and no_hwp would be disregarded. > > > > > > > > Something like the attached, for the record. > > > > > > O.K. and Thanks. > > > I was trying to avoid this line getting into the log: > > > > > > [ 0.000000] intel_pstate: HWP disabled > > > > > > only to overridden later by, now, these lines: > > > > > > [ 0.373742] intel_pstate: HWP enabled by BIOS > > > [ 0.374177] intel_pstate: Intel P-state driver initializing > > > [ 0.375097] intel_pstate: HWP enabled > > > > > > Let me see if I can go with your suggestion and get to > > > what I had hoped to get in the logs. > > > > It would be sufficient to put the "disabled" printk() after the > > "no_hwp" if () statement in intel_pstate_init(). See attached. > > Agreed, thanks. Yes, I was thinking similar. > > > BTW, I've changed the message to "HWP not enabled", because that's > > what really happens to be precise. > > Agreed. Good idea. > > Give me a fews days to create and test a formal patch. OK > I currently have limited access to a computer that doesn't force > HWP via BIOS.
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index bb4549959b11..073bae5d4498 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -3267,7 +3267,7 @@ static int __init intel_pstate_init(void) */ if ((!no_hwp && boot_cpu_has(X86_FEATURE_HWP_EPP)) || intel_pstate_hwp_is_enabled()) { - hwp_active++; + hwp_active = 1; hwp_mode_bdw = id->driver_data; intel_pstate.attr = hwp_cpufreq_attrs; intel_cpufreq.attr = hwp_cpufreq_attrs; @@ -3347,17 +3347,27 @@ device_initcall(intel_pstate_init); static int __init intel_pstate_setup(char *str) { + /* + * If BIOS is forcing HWP, then parameter + * overrides might be needed. Only print + * the message once, and regardless of + * any overrides. + */ + if(!hwp_active && boot_cpu_has(X86_FEATURE_HWP)) + if(intel_pstate_hwp_is_enabled()){ + pr_info("HWP enabled by BIOS\n"); + hwp_active = 1; + } if (!str) return -EINVAL; - if (!strcmp(str, "disable")) + if (!strcmp(str, "disable") && !hwp_active) no_load = 1; - else if (!strcmp(str, "active")) + if (!strcmp(str, "active")) default_driver = &intel_pstate; - else if (!strcmp(str, "passive")) + if (!strcmp(str, "passive")) default_driver = &intel_cpufreq; - - if (!strcmp(str, "no_hwp")) { + if (!strcmp(str, "no_hwp") && !hwp_active) { pr_info("HWP disabled\n"); no_hwp = 1; }
If HWP has been already been enabled by BIOS, it may be necessary to override some kernel command line parameters. Once it has been enabled it requires a reset to be disabled. Signed-off-by: Doug Smythies <dsmythies@telus.net> --- drivers/cpufreq/intel_pstate.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-)