| Message ID | 20130306150515.GD10760@phenom.dumpdata.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Wednesday, March 06, 2013 10:05:15 AM Konrad Rzeszutek Wilk wrote: > On Wed, Mar 06, 2013 at 01:29:49AM +0100, Rafael J. Wysocki wrote: > > Hi, > > > > Thanks for the report. -> > > > > On Tuesday, March 05, 2013 01:39:19 PM Konrad Rzeszutek Wilk wrote: > > > In all fairness, the commit d5aaffa9dd531c978c6f3fea06a2972653bd7fc8 > > > (cpufreq: handle cpufreq being disabled for all exported function.) is not > > > at fault - it just that it exposes an assumption that before v3.9-rc1 > > > was not true. And git bisection points to it :-( > .. snip.. > > > Thoughts? > > > > Well, since your patch above seems to only affect Xen, I'm basically fine with > > it. > > OK, here is the patch. Would you like to carry it in my tree for Linus or are > you comfortable taking it? Well, if you can push it to Linus, please do that. It belongs to the Xen tree rather than to mine. Thanks, Rafael > From c705c78c0d0835a4aa5d0d9a3422e3218462030c Mon Sep 17 00:00:00 2001 > From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > Date: Tue, 5 Mar 2013 13:42:54 -0500 > Subject: [PATCH] acpi: Export the acpi_processor_get_performance_info > > The git commit d5aaffa9dd531c978c6f3fea06a2972653bd7fc8 > (cpufreq: handle cpufreq being disabled for all exported function) > tightens the cpufreq API by returning errors when disable_cpufreq() > had been called. > > The problem we are hitting is that the module xen-acpi-processor which > uses the ACPI's functions: acpi_processor_register_performance, > acpi_processor_preregister_performance, and acpi_processor_notify_smm > fails at acpi_processor_register_performance with -22. > > Note that earlier during bootup in arch/x86/xen/setup.c there is also > an call to cpufreq's API: disable_cpufreq(). > > This is b/c we want the Linux kernel to parse the ACPI data, but leave > the cpufreq decisions to the hypervisor. > > In v3.9 all the checks that d5aaffa9dd531c978c6f3fea06a2972653bd7fc8 > added are now hit and the calls to cpufreq_register_notifier will now > fail. This means that acpi_processor_ppc_init ends up printing: > > "Warning: Processor Platform Limit not supported" > > and the acpi_processor_ppc_status is not set. > > The repercussions of that is that the call to > acpi_processor_register_performance fails right away at: > > if (!(acpi_processor_ppc_status & PPC_REGISTERED)) > > and we don't progress any further on parsing and extracting the _P* > objects. > > The only reason the Xen code called that function was b/c it was > exported and the only way to gather the P-states. But we can also > just make acpi_processor_get_performance_info be exported and not > use acpi_processor_register_performance. This patch does so. > > Acked-by: Rafael J. Wysocki <rjw@sisk.pl> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > --- > drivers/acpi/processor_perflib.c | 4 ++-- > drivers/xen/xen-acpi-processor.c | 8 ++++---- > include/acpi/processor.h | 3 +++ > 3 files changed, 9 insertions(+), 6 deletions(-) > > diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c > index 53e7ac9..e854582 100644 > --- a/drivers/acpi/processor_perflib.c > +++ b/drivers/acpi/processor_perflib.c > @@ -465,7 +465,7 @@ static int acpi_processor_get_performance_states(struct acpi_processor *pr) > return result; > } > > -static int acpi_processor_get_performance_info(struct acpi_processor *pr) > +int acpi_processor_get_performance_info(struct acpi_processor *pr) > { > int result = 0; > acpi_status status = AE_OK; > @@ -509,7 +509,7 @@ static int acpi_processor_get_performance_info(struct acpi_processor *pr) > #endif > return result; > } > - > +EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info); > int acpi_processor_notify_smm(struct module *calling_module) > { > acpi_status status; > diff --git a/drivers/xen/xen-acpi-processor.c b/drivers/xen/xen-acpi-processor.c > index 316df65..f3278a6 100644 > --- a/drivers/xen/xen-acpi-processor.c > +++ b/drivers/xen/xen-acpi-processor.c > @@ -500,16 +500,16 @@ static int __init xen_acpi_processor_init(void) > (void)acpi_processor_preregister_performance(acpi_perf_data); > > for_each_possible_cpu(i) { > + struct acpi_processor *pr; > struct acpi_processor_performance *perf; > > + pr = per_cpu(processors, i); > perf = per_cpu_ptr(acpi_perf_data, i); > - rc = acpi_processor_register_performance(perf, i); > + pr->performance = perf; > + rc = acpi_processor_get_performance_info(pr); > if (rc) > goto err_out; > } > - rc = acpi_processor_notify_smm(THIS_MODULE); > - if (rc) > - goto err_unregister; > > for_each_possible_cpu(i) { > struct acpi_processor *_pr; > diff --git a/include/acpi/processor.h b/include/acpi/processor.h > index 555d033..b327b5a 100644 > --- a/include/acpi/processor.h > +++ b/include/acpi/processor.h > @@ -235,6 +235,9 @@ extern void acpi_processor_unregister_performance(struct > if a _PPC object exists, rmmod is disallowed then */ > int acpi_processor_notify_smm(struct module *calling_module); > > +/* parsing the _P* objects. */ > +extern int acpi_processor_get_performance_info(struct acpi_processor *pr); > + > /* for communication between multiple parts of the processor kernel module */ > DECLARE_PER_CPU(struct acpi_processor *, processors); > extern struct acpi_processor_errata errata; >
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c index 53e7ac9..e854582 100644 --- a/drivers/acpi/processor_perflib.c +++ b/drivers/acpi/processor_perflib.c @@ -465,7 +465,7 @@ static int acpi_processor_get_performance_states(struct acpi_processor *pr) return result; } -static int acpi_processor_get_performance_info(struct acpi_processor *pr) +int acpi_processor_get_performance_info(struct acpi_processor *pr) { int result = 0; acpi_status status = AE_OK; @@ -509,7 +509,7 @@ static int acpi_processor_get_performance_info(struct acpi_processor *pr) #endif return result; } - +EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info); int acpi_processor_notify_smm(struct module *calling_module) { acpi_status status; diff --git a/drivers/xen/xen-acpi-processor.c b/drivers/xen/xen-acpi-processor.c index 316df65..f3278a6 100644 --- a/drivers/xen/xen-acpi-processor.c +++ b/drivers/xen/xen-acpi-processor.c @@ -500,16 +500,16 @@ static int __init xen_acpi_processor_init(void) (void)acpi_processor_preregister_performance(acpi_perf_data); for_each_possible_cpu(i) { + struct acpi_processor *pr; struct acpi_processor_performance *perf; + pr = per_cpu(processors, i); perf = per_cpu_ptr(acpi_perf_data, i); - rc = acpi_processor_register_performance(perf, i); + pr->performance = perf; + rc = acpi_processor_get_performance_info(pr); if (rc) goto err_out; } - rc = acpi_processor_notify_smm(THIS_MODULE); - if (rc) - goto err_unregister; for_each_possible_cpu(i) { struct acpi_processor *_pr; diff --git a/include/acpi/processor.h b/include/acpi/processor.h index 555d033..b327b5a 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -235,6 +235,9 @@ extern void acpi_processor_unregister_performance(struct if a _PPC object exists, rmmod is disallowed then */ int acpi_processor_notify_smm(struct module *calling_module); +/* parsing the _P* objects. */ +extern int acpi_processor_get_performance_info(struct acpi_processor *pr); + /* for communication between multiple parts of the processor kernel module */ DECLARE_PER_CPU(struct acpi_processor *, processors); extern struct acpi_processor_errata errata;