[XEN PATCH v3 2/2] x86/cpufreq: separate powernow/hwp/acpi cpufreq code

[Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>]

Build AMD Architectural P-state driver when CONFIG_AMD is on, and
Intel Hardware P-States driver together with ACPI Processor P-States driver
when CONFIG_INTEL is on respectively, allowing for a platform-specific build.

Signed-off-by: Sergiy Kibrik <Sergiy_Kibrik@xxxxxxxx>
CC: Jason Andryuk <jason.andryuk@xxxxxxx>
CC: Jan Beulich <jbeulich@xxxxxxxx>
---
changes in v3:
 - more clear wrapping of lines in conditionals + put IS_ENABLED() in front
 - drop unneeded change to utility.c
changes in v2:
 - disable acpi-cpufreq driver as well when !INTEL
 - leave a stub for hwp_active() only when !INTEL
 - updated patch description
---
 xen/arch/x86/acpi/cpufreq/Makefile  | 6 +++---
 xen/arch/x86/acpi/cpufreq/cpufreq.c | 8 +++++---
 xen/drivers/acpi/pmstat.c           | 5 +++--
 xen/drivers/cpufreq/cpufreq.c       | 3 ++-
 xen/include/acpi/cpufreq/cpufreq.h  | 8 ++++++++
 5 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/xen/arch/x86/acpi/cpufreq/Makefile 
b/xen/arch/x86/acpi/cpufreq/Makefile
index 44d4c0b497..e7dbe434a8 100644
--- a/xen/arch/x86/acpi/cpufreq/Makefile
+++ b/xen/arch/x86/acpi/cpufreq/Makefile
@@ -1,4 +1,4 @@
-obj-y += acpi.o
+obj-$(CONFIG_INTEL) += acpi.o
 obj-y += cpufreq.o
-obj-y += hwp.o
-obj-y += powernow.o
+obj-$(CONFIG_INTEL) += hwp.o
+obj-$(CONFIG_AMD) += powernow.o
diff --git a/xen/arch/x86/acpi/cpufreq/cpufreq.c 
b/xen/arch/x86/acpi/cpufreq/cpufreq.c
index 6244d29496..61e98b67bd 100644
--- a/xen/arch/x86/acpi/cpufreq/cpufreq.c
+++ b/xen/arch/x86/acpi/cpufreq/cpufreq.c
@@ -138,10 +138,12 @@ static int __init cf_check cpufreq_driver_init(void)
                 switch ( cpufreq_xen_opts[i] )
                 {
                 case CPUFREQ_xen:
-                    ret = acpi_cpufreq_register();
+                    ret = IS_ENABLED(CONFIG_INTEL) ?
+                          acpi_cpufreq_register() : -ENODEV;
                     break;
                 case CPUFREQ_hwp:
-                    ret = hwp_register_driver();
+                    ret = IS_ENABLED(CONFIG_INTEL) ?
+                          hwp_register_driver() : -ENODEV;
                     break;
                 case CPUFREQ_none:
                     ret = 0;
@@ -155,7 +157,7 @@ static int __init cf_check cpufreq_driver_init(void)
 
         case X86_VENDOR_AMD:
         case X86_VENDOR_HYGON:
-            ret = powernow_register_driver();
+            ret = IS_ENABLED(CONFIG_AMD) ? powernow_register_driver() : 
-ENODEV;
             break;
         }
     }
diff --git a/xen/drivers/acpi/pmstat.c b/xen/drivers/acpi/pmstat.c
index 998d2e3c65..df309e27b4 100644
--- a/xen/drivers/acpi/pmstat.c
+++ b/xen/drivers/acpi/pmstat.c
@@ -254,8 +254,9 @@ static int get_cpufreq_para(struct xen_sysctl_pm_op *op)
     else
         strlcpy(op->u.get_para.scaling_driver, "Unknown", CPUFREQ_NAME_LEN);
 
-    if ( !strncmp(op->u.get_para.scaling_driver, XEN_HWP_DRIVER_NAME,
-                      CPUFREQ_NAME_LEN) )
+    if ( IS_ENABLED(CONFIG_INTEL) &&
+         !strncmp(op->u.get_para.scaling_driver, XEN_HWP_DRIVER_NAME,
+                  CPUFREQ_NAME_LEN) )
         ret = get_hwp_para(policy->cpu, &op->u.get_para.u.cppc_para);
     else
     {
diff --git a/xen/drivers/cpufreq/cpufreq.c b/xen/drivers/cpufreq/cpufreq.c
index 8659ad3aee..4a103c6de9 100644
--- a/xen/drivers/cpufreq/cpufreq.c
+++ b/xen/drivers/cpufreq/cpufreq.c
@@ -120,7 +120,8 @@ static int __init cf_check setup_cpufreq_option(const char 
*str)
             if ( arg[0] && arg[1] )
                 ret = cpufreq_cmdline_parse(arg + 1, end);
         }
-        else if ( choice < 0 && !cmdline_strcmp(str, "hwp") )
+        else if ( IS_ENABLED(CONFIG_INTEL) && choice < 0 &&
+                  !cmdline_strcmp(str, "hwp") )
         {
             xen_processor_pmbits |= XEN_PROCESSOR_PM_PX;
             cpufreq_controller = FREQCTL_xen;
diff --git a/xen/include/acpi/cpufreq/cpufreq.h 
b/xen/include/acpi/cpufreq/cpufreq.h
index ec7e139000..08ee2af0f8 100644
--- a/xen/include/acpi/cpufreq/cpufreq.h
+++ b/xen/include/acpi/cpufreq/cpufreq.h
@@ -254,7 +254,15 @@ void intel_feature_detect(struct cpufreq_policy *policy);
 
 int hwp_cmdline_parse(const char *s, const char *e);
 int hwp_register_driver(void);
+#ifdef CONFIG_INTEL
 bool hwp_active(void);
+#else
+static inline bool hwp_active(void)
+{
+    return false;
+}
+#endif
+
 int get_hwp_para(unsigned int cpu,
                  struct xen_cppc_para *cppc_para);
 int set_hwp_para(struct cpufreq_policy *policy,
-- 
2.25.1