From 1d4c763f74da51bd5bb269282d740fb641ba8aa1 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Tue, 5 Mar 2013 13:42:54 -0500 Subject: [PATCH] acpi: Export the acpi_processor_get_performance_info The git commit f875f614f8b02f1185cbfa7eea03d874920732fb (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 f875f614f8b02f1185cbfa7eea03d874920732fb 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 Signed-off-by: Konrad Rzeszutek Wilk --- 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 53e7ac9403a7d..e854582f29a67 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 316df65163cfa..f3278a6603ca3 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 555d0337ad955..b327b5a9296d3 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; -- 2.39.5