cpufreq: Add cpufreq driver for LoongArch

LoongArch inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I6BWFP

--------------------------------
Signed-off-by: Nzhangtianyang <zhangtianyang@loongson.cn>
Change-Id: Ic9390a1c78e1670422be1b03d35e3f0fdec1367f

arch/loongarch/Kconfig

@@ -514,4 +514,10 @@ source "drivers/acpi/Kconfig"
 
 endmenu
 
+menu "CPU Power Management"
+
+source "drivers/cpufreq/Kconfig"
+
+endmenu
+
 source "drivers/firmware/Kconfig"

arch/loongarch/configs/loongson3_defconfig

@@ -43,6 +43,10 @@ CONFIG_ACPI_SPCR_TABLE=y
 CONFIG_ACPI_DOCK=y
 CONFIG_ACPI_IPMI=m
 CONFIG_ACPI_PCI_SLOT=y
+CONFIG_CPU_FREQ=y
+CONFIG_CPU_FREQ_STAT=y
+CONFIG_CPU_FREQ_GOV_POWERSAVE=y
+CONFIG_LOONGSON3_ACPI_CPUFREQ=y
 CONFIG_EFI_CAPSULE_LOADER=m
 CONFIG_EFI_TEST=m
 CONFIG_MODULES=y

arch/loongarch/include/asm/fpu.h

@@ -45,6 +45,10 @@ static inline void disable_lasx(void);
 static inline void save_lasx(struct task_struct *t);
 static inline void restore_lasx(struct task_struct *t);
 
+#ifdef CONFIG_LOONGSON3_ACPI_CPUFREQ
+DECLARE_PER_CPU(unsigned long, msa_count);
+DECLARE_PER_CPU(unsigned long, lasx_count);
+#endif
 /*
  * Mask the FCSR Cause bits according to the Enable bits, observing
  * that Unimplemented is always enabled.
@@ -198,6 +202,9 @@ static inline void enable_lsx(void)
 {
 	if (cpu_has_lsx)
 		csr_xchg32(CSR_EUEN_LSXEN, CSR_EUEN_LSXEN, LOONGARCH_CSR_EUEN);
+#ifdef CONFIG_LOONGSON3_ACPI_CPUFREQ
+		per_cpu(msa_count, raw_smp_processor_id())++;
+#endif
 }
 
 static inline void disable_lsx(void)
@@ -251,8 +258,12 @@ static inline void restore_lsx_upper(struct task_struct *t) {}
 static inline void enable_lasx(void)
 {
 
-	if (cpu_has_lasx)
+	if (cpu_has_lasx) {
 		csr_xchg32(CSR_EUEN_LASXEN, CSR_EUEN_LASXEN, LOONGARCH_CSR_EUEN);
+#ifdef CONFIG_LOONGSON3_ACPI_CPUFREQ
+		per_cpu(lasx_count, raw_smp_processor_id())++;
+#endif
+	}
 }
 
 static inline void disable_lasx(void)

drivers/cpufreq/Kconfig

@@ -287,6 +287,17 @@ config LOONGSON1_CPUFREQ
 	  If in doubt, say N.
 endif
 
+if LOONGARCH
+config LOONGSON3_ACPI_CPUFREQ
+	bool "Loongson3 ACPI cpufreq driver"
+	depends on ACPI_PROCESSOR
+	help
+	  This driver adds a CPUFreq driver which utilizes the ACPI
+	  Processor Performance States.
+	  This driver supports Loongson 3A5000 compatible CPUs.
+	  If in doubt, say N.
+endif
+
 if SPARC64
 config SPARC_US3_CPUFREQ
 	tristate "UltraSPARC-III CPU Frequency driver"

drivers/cpufreq/Makefile

@@ -106,6 +106,7 @@ obj-$(CONFIG_BMIPS_CPUFREQ)		+= bmips-cpufreq.o
 obj-$(CONFIG_IA64_ACPI_CPUFREQ)		+= ia64-acpi-cpufreq.o
 obj-$(CONFIG_LOONGSON2_CPUFREQ)		+= loongson2_cpufreq.o
 obj-$(CONFIG_LOONGSON1_CPUFREQ)		+= loongson1-cpufreq.o
+obj-$(CONFIG_LOONGSON3_ACPI_CPUFREQ)	+= loongson3-acpi-cpufreq.o
 obj-$(CONFIG_SH_CPU_FREQ)		+= sh-cpufreq.o
 obj-$(CONFIG_SPARC_US2E_CPUFREQ)	+= sparc-us2e-cpufreq.o
 obj-$(CONFIG_SPARC_US3_CPUFREQ)		+= sparc-us3-cpufreq.o