This series add architectural preparation and CPUFreq driver for
Loongson-3 (based on LoongArch).
Some of LoongArch processors support DVFS, their IOCSR.FEATURES has
IOCSRF_FREQSCALE set. And they has a micro-core in the package called
SMC (System Management Controller) to scale frequency, voltage, etc.
Huacai Chen(2):
LoongArch: Add architectural preparation for CPUFreq.
cpufreq: Add Loongson-3 CPUFreq driver support.
Signed-off-by: Huacai Chen <[email protected]>
---
2.27.0
Add architectural preparation for CPUFreq driver, including: Kconfig,
register definition and platform device registration.
Some of LoongArch processors support DVFS, their IOCSR.FEATURES has
IOCSRF_FREQSCALE set. And they has a micro-core in the package called
SMC (System Management Controller) to scale frequency, voltage, etc.
Signed-off-by: Binbin Zhou <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
---
arch/loongarch/Kconfig | 1 +
arch/loongarch/include/asm/loongarch.h | 3 +++
arch/loongarch/power/platform.c | 15 +++++++++++++++
3 files changed, 19 insertions(+)
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index e38139c576ee..dffa9c454123 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -696,6 +696,7 @@ config ARCH_HIBERNATION_POSSIBLE
source "kernel/power/Kconfig"
source "drivers/acpi/Kconfig"
+source "drivers/cpufreq/Kconfig"
endmenu
diff --git a/arch/loongarch/include/asm/loongarch.h b/arch/loongarch/include/asm/loongarch.h
index eb09adda54b7..7d89b2ecf2c2 100644
--- a/arch/loongarch/include/asm/loongarch.h
+++ b/arch/loongarch/include/asm/loongarch.h
@@ -1053,11 +1053,14 @@
#define LOONGARCH_IOCSR_NODECNT 0x408
#define LOONGARCH_IOCSR_MISC_FUNC 0x420
+#define IOCSR_MISC_FUNC_SOFT_INT BIT_ULL(10)
#define IOCSR_MISC_FUNC_TIMER_RESET BIT_ULL(21)
#define IOCSR_MISC_FUNC_EXT_IOI_EN BIT_ULL(48)
#define LOONGARCH_IOCSR_CPUTEMP 0x428
+#define LOONGARCH_IOCSR_SMCMBX 0x51c
+
/* PerCore CSR, only accessible by local cores */
#define LOONGARCH_IOCSR_IPI_STATUS 0x1000
#define LOONGARCH_IOCSR_IPI_EN 0x1004
diff --git a/arch/loongarch/power/platform.c b/arch/loongarch/power/platform.c
index 3ea8e07aa225..a19353f7d1b0 100644
--- a/arch/loongarch/power/platform.c
+++ b/arch/loongarch/power/platform.c
@@ -34,6 +34,21 @@ void enable_pci_wakeup(void)
acpi_write_bit_register(ACPI_BITREG_PCIEXP_WAKE_DISABLE, 0);
}
+static struct platform_device loongson3_cpufreq_device = {
+ .name = "loongson3_cpufreq",
+ .id = -1,
+};
+
+static int __init loongson_cpufreq_init(void)
+{
+ if (!cpu_has_scalefreq)
+ return -ENODEV;
+
+ return platform_device_register(&loongson3_cpufreq_device);
+}
+
+arch_initcall(loongson_cpufreq_init);
+
static int __init loongson3_acpi_suspend_init(void)
{
#ifdef CONFIG_ACPI
--
2.43.0
Some of LoongArch processors (Loongson-3 series) support DVFS, their
IOCSR.FEATURES has IOCSRF_FREQSCALE set. And they has a micro-core in
the package called SMC (System Management Controller), which can be
used to detect temperature, control fans, scale frequency and voltage,
etc.
The Loongson-3 CPUFreq driver is very simple now, it communicate with
SMC, get DVFS info, set target frequency from CPUFreq core, and so on.
There is a command list to interact with SMC, widely-used commands in
the CPUFreq driver include:
CMD_GET_VERSION: Get SMC firmware version.
CMD_GET_FEATURE: Get enabled SMC features.
CMD_SET_FEATURE: Enable SMC features, such as basic DVFS, BOOST.
CMD_GET_FREQ_LEVEL_NUM: Get the number of normal frequency levels.
CMD_GET_FREQ_BOOST_NUM: Get the number of boost frequency levels.
CMD_GET_FREQ_LEVEL_INFO: Get the detail info of a frequency level.
CMD_GET_FREQ_INFO: Get the current frequency.
CMD_SET_FREQ_INFO: Set the target frequency.
In future we will add automatic frequency scaling, which is similar to
Intel's HWP (HardWare P-State).
Signed-off-by: Binbin Zhou <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
---
drivers/cpufreq/Kconfig | 12 +
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/loongson3_cpufreq.c | 442 ++++++++++++++++++++++++++++
3 files changed, 455 insertions(+)
create mode 100644 drivers/cpufreq/loongson3_cpufreq.c
diff --git a/MAINTAINERS b/MAINTAINERS
index aacccb376c28..f2e47ec28d77 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12968,6 +12968,7 @@ F: Documentation/arch/loongarch/
F: Documentation/translations/zh_CN/arch/loongarch/
F: arch/loongarch/
F: drivers/*/*loongarch*
+F: drivers/cpufreq/loongson3_cpufreq.c
LOONGSON GPIO DRIVER
M: Yinbo Zhu <[email protected]>
diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig
index 94e55c40970a..10cda6f2fe1d 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -262,6 +262,18 @@ config LOONGSON2_CPUFREQ
If in doubt, say N.
endif
+if LOONGARCH
+config LOONGSON3_CPUFREQ
+ tristate "Loongson3 CPUFreq Driver"
+ help
+ This option adds a CPUFreq driver for Loongson processors which
+ support software configurable cpu frequency.
+
+ Loongson-3 family processors support this feature.
+
+ If in doubt, say N.
+endif
+
if SPARC64
config SPARC_US3_CPUFREQ
tristate "UltraSPARC-III CPU Frequency driver"
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 8d141c71b016..0f184031dd12 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -103,6 +103,7 @@ obj-$(CONFIG_POWERNV_CPUFREQ) += powernv-cpufreq.o
# Other platform drivers
obj-$(CONFIG_BMIPS_CPUFREQ) += bmips-cpufreq.o
obj-$(CONFIG_LOONGSON2_CPUFREQ) += loongson2_cpufreq.o
+obj-$(CONFIG_LOONGSON3_CPUFREQ) += loongson3_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
diff --git a/drivers/cpufreq/loongson3_cpufreq.c b/drivers/cpufreq/loongson3_cpufreq.c
new file mode 100644
index 000000000000..5dbac0d55a32
--- /dev/null
+++ b/drivers/cpufreq/loongson3_cpufreq.c
@@ -0,0 +1,442 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * CPUFreq driver for the loongson-3 processors
+ *
+ * All revisions of Loongson-3 processor support this feature.
+ *
+ * Author: Huacai Chen <[email protected]>
+ * Copyright (C) 2020-2024 Loongson Technology Corporation Limited
+ */
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/cpufreq.h>
+#include <linux/platform_device.h>
+#include <linux/units.h>
+
+#include <asm/idle.h>
+#include <asm/loongarch.h>
+#include <asm/loongson.h>
+
+/* Message */
+union smc_message {
+ u32 value;
+ struct {
+ u32 id : 4;
+ u32 info : 4;
+ u32 val : 16;
+ u32 cmd : 6;
+ u32 extra : 1;
+ u32 complete : 1;
+ };
+};
+
+/* Command return values */
+#define CMD_OK 0 /* No error */
+#define CMD_ERROR 1 /* Regular error */
+#define CMD_NOCMD 2 /* Command does not support */
+#define CMD_INVAL 3 /* Invalid Parameter */
+
+/* Version commands */
+/*
+ * CMD_GET_VERSION - Get interface version
+ * Input: none
+ * Output: version
+ */
+#define CMD_GET_VERSION 0x1
+
+/* Feature commands */
+/*
+ * CMD_GET_FEATURE - Get feature state
+ * Input: feature ID
+ * Output: feature flag
+ */
+#define CMD_GET_FEATURE 0x2
+
+/*
+ * CMD_SET_FEATURE - Set feature state
+ * Input: feature ID, feature flag
+ * output: none
+ */
+#define CMD_SET_FEATURE 0x3
+
+/* Feature IDs */
+#define FEATURE_SENSOR 0
+#define FEATURE_FAN 1
+#define FEATURE_DVFS 2
+
+/* Sensor feature flags */
+#define FEATURE_SENSOR_ENABLE BIT(0)
+#define FEATURE_SENSOR_SAMPLE BIT(1)
+
+/* Fan feature flags */
+#define FEATURE_FAN_ENABLE BIT(0)
+#define FEATURE_FAN_AUTO BIT(1)
+
+/* DVFS feature flags */
+#define FEATURE_DVFS_ENABLE BIT(0)
+#define FEATURE_DVFS_BOOST BIT(1)
+#define FEATURE_DVFS_AUTO BIT(2)
+#define FEATURE_DVFS_SINGLE_BOOST BIT(3)
+
+/* Sensor commands */
+/*
+ * CMD_GET_SENSOR_NUM - Get number of sensors
+ * Input: none
+ * Output: number
+ */
+#define CMD_GET_SENSOR_NUM 0x4
+
+/*
+ * CMD_GET_SENSOR_STATUS - Get sensor status
+ * Input: sensor ID, type
+ * Output: sensor status
+ */
+#define CMD_GET_SENSOR_STATUS 0x5
+
+/* Sensor types */
+#define SENSOR_INFO_TYPE 0
+#define SENSOR_INFO_TYPE_TEMP 1
+
+/* Fan commands */
+/*
+ * CMD_GET_FAN_NUM - Get number of fans
+ * Input: none
+ * Output: number
+ */
+#define CMD_GET_FAN_NUM 0x6
+
+/*
+ * CMD_GET_FAN_INFO - Get fan status
+ * Input: fan ID, type
+ * Output: fan info
+ */
+#define CMD_GET_FAN_INFO 0x7
+
+/*
+ * CMD_SET_FAN_INFO - Set fan status
+ * Input: fan ID, type, value
+ * Output: none
+ */
+#define CMD_SET_FAN_INFO 0x8
+
+/* Fan types */
+#define FAN_INFO_TYPE_LEVEL 0
+
+/* DVFS commands */
+/*
+ * CMD_GET_FREQ_LEVEL_NUM - Get number of freq levels
+ * Input: CPU ID
+ * Output: number
+ */
+#define CMD_GET_FREQ_LEVEL_NUM 0x9
+
+/*
+ * CMD_GET_FREQ_BOOST_LEVEL - Get number of boost levels
+ * Input: CPU ID
+ * Output: number
+ */
+#define CMD_GET_FREQ_BOOST_LEVEL 0x10
+
+/*
+ * CMD_GET_FREQ_LEVEL_INFO - Get freq level info
+ * Input: CPU ID, level ID
+ * Output: level info
+ */
+#define CMD_GET_FREQ_LEVEL_INFO 0x11
+
+/*
+ * CMD_GET_FREQ_INFO - Get freq info
+ * Input: CPU ID, type
+ * Output: freq info
+ */
+#define CMD_GET_FREQ_INFO 0x12
+
+/*
+ * CMD_SET_FREQ_INFO - Set freq info
+ * Input: CPU ID, type, value
+ * Output: none
+ */
+#define CMD_SET_FREQ_INFO 0x13
+
+/* Freq types */
+#define FREQ_INFO_TYPE_FREQ 0
+#define FREQ_INFO_TYPE_LEVEL 1
+
+#define FREQ_MAX_LEVEL (16 + 1)
+
+enum freq {
+ FREQ_LEV0, /* Reserved */
+ FREQ_LEV1, FREQ_LEV2, FREQ_LEV3, FREQ_LEV4,
+ FREQ_LEV5, FREQ_LEV6, FREQ_LEV7, FREQ_LEV8,
+ FREQ_LEV9, FREQ_LEV10, FREQ_LEV11, FREQ_LEV12,
+ FREQ_LEV13, FREQ_LEV14, FREQ_LEV15, FREQ_LEV16,
+ FREQ_RESV
+};
+
+struct loongson3_freq_data {
+ unsigned int cur_cpu_freq;
+ struct cpufreq_frequency_table table[];
+};
+
+static struct mutex cpufreq_mutex[MAX_PACKAGES];
+static struct cpufreq_driver loongson3_cpufreq_driver;
+static DEFINE_PER_CPU(struct loongson3_freq_data *, freq_data);
+
+static inline int do_service_request(union smc_message *msg)
+{
+ int retries;
+ union smc_message last;
+
+ last.value = iocsr_read32(LOONGARCH_IOCSR_SMCMBX);
+ if (!last.complete)
+ return -EPERM;
+
+ iocsr_write32(msg->value, LOONGARCH_IOCSR_SMCMBX);
+ iocsr_write32(iocsr_read32(LOONGARCH_IOCSR_MISC_FUNC) | IOCSR_MISC_FUNC_SOFT_INT,
+ LOONGARCH_IOCSR_MISC_FUNC);
+
+ for (retries = 0; retries < 10000; retries++) {
+ msg->value = iocsr_read32(LOONGARCH_IOCSR_SMCMBX);
+ if (msg->complete)
+ break;
+
+ usleep_range(8, 12);
+ }
+
+ if (!msg->complete || msg->cmd != CMD_OK)
+ return -EPERM;
+
+ return 0;
+}
+
+static unsigned int loongson3_cpufreq_get(unsigned int cpu)
+{
+ union smc_message msg;
+
+ msg.id = cpu;
+ msg.info = FREQ_INFO_TYPE_FREQ;
+ msg.cmd = CMD_GET_FREQ_INFO;
+ msg.extra = 0;
+ msg.complete = 0;
+ do_service_request(&msg);
+
+ per_cpu(freq_data, cpu)->cur_cpu_freq = msg.val * KILO;
+
+ return per_cpu(freq_data, cpu)->cur_cpu_freq;
+}
+
+static int loongson3_cpufreq_set(struct cpufreq_policy *policy, int freq_level)
+{
+ union smc_message msg;
+
+ msg.id = cpu_data[policy->cpu].core;
+ msg.info = FREQ_INFO_TYPE_LEVEL;
+ msg.val = freq_level;
+ msg.cmd = CMD_SET_FREQ_INFO;
+ msg.extra = 0;
+ msg.complete = 0;
+ do_service_request(&msg);
+
+ return 0;
+}
+
+/*
+ * Here we notify other drivers of the proposed change and the final change.
+ */
+static int loongson3_cpufreq_target(struct cpufreq_policy *policy, unsigned int index)
+{
+ unsigned int cpu = policy->cpu;
+ unsigned int package = cpu_data[cpu].package;
+
+ if (!cpu_online(cpu))
+ return -ENODEV;
+
+ /* setting the cpu frequency */
+ mutex_lock(&cpufreq_mutex[package]);
+ loongson3_cpufreq_set(policy, index);
+ mutex_unlock(&cpufreq_mutex[package]);
+
+ return 0;
+}
+
+static int loongson3_cpufreq_get_freq_table(int cpu)
+{
+ union smc_message msg;
+ int i, ret, boost_level, max_level, freq_level;
+ struct loongson3_freq_data *data;
+
+ if (per_cpu(freq_data, cpu))
+ return 0;
+
+ msg.id = cpu;
+ msg.cmd = CMD_GET_FREQ_LEVEL_NUM;
+ msg.extra = 0;
+ msg.complete = 0;
+ ret = do_service_request(&msg);
+ if (ret < 0)
+ return ret;
+ max_level = msg.val;
+
+ msg.id = cpu;
+ msg.cmd = CMD_GET_FREQ_BOOST_LEVEL;
+ msg.extra = 0;
+ msg.complete = 0;
+ ret = do_service_request(&msg);
+ if (ret < 0)
+ return ret;
+ boost_level = msg.val;
+
+ freq_level = min(max_level, FREQ_MAX_LEVEL);
+ data = kzalloc(struct_size(data, table, freq_level + 1), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ for (i = 0; i < freq_level; i++) {
+ msg.id = cpu;
+ msg.info = FREQ_INFO_TYPE_FREQ;
+ msg.cmd = CMD_GET_FREQ_LEVEL_INFO;
+ msg.val = i;
+ msg.complete = 0;
+
+ ret = do_service_request(&msg);
+ if (ret < 0) {
+ kfree(data);
+ return ret;
+ }
+
+ data->table[i].frequency = msg.val * KILO;
+ data->table[i].driver_data = FREQ_LEV0 + i;
+ data->table[i].flags = (i >= boost_level) ? CPUFREQ_BOOST_FREQ : 0;
+ }
+
+ data->table[freq_level].frequency = CPUFREQ_TABLE_END;
+ data->table[freq_level].driver_data = FREQ_RESV;
+ data->table[freq_level].flags = 0;
+
+ per_cpu(freq_data, cpu) = data;
+
+ return 0;
+}
+
+static int loongson3_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+ int ret;
+
+ if (!cpu_online(policy->cpu))
+ return -ENODEV;
+
+ ret = loongson3_cpufreq_get_freq_table(policy->cpu);
+ if (ret < 0)
+ return ret;
+
+ policy->cur = loongson3_cpufreq_get(policy->cpu);
+ policy->cpuinfo.transition_latency = 10000;
+ policy->freq_table = per_cpu(freq_data, policy->cpu)->table;
+ cpumask_copy(policy->cpus, topology_sibling_cpumask(policy->cpu));
+
+ if (policy_has_boost_freq(policy)) {
+ ret = cpufreq_enable_boost_support();
+ if (ret < 0) {
+ pr_warn("cpufreq: Failed to enable boost: %d\n", ret);
+ return ret;
+ }
+ loongson3_cpufreq_driver.boost_enabled = true;
+ }
+
+ return 0;
+}
+
+static int loongson3_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+ return 0;
+}
+
+static struct cpufreq_driver loongson3_cpufreq_driver = {
+ .name = "loongson3",
+ .flags = CPUFREQ_CONST_LOOPS,
+ .init = loongson3_cpufreq_cpu_init,
+ .exit = loongson3_cpufreq_cpu_exit,
+ .verify = cpufreq_generic_frequency_table_verify,
+ .target_index = loongson3_cpufreq_target,
+ .get = loongson3_cpufreq_get,
+ .attr = cpufreq_generic_attr,
+};
+
+static struct platform_device_id cpufreq_id_table[] = {
+ { "loongson3_cpufreq", },
+ { /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(platform, cpufreq_id_table);
+
+static struct platform_driver loongson3_platform_driver = {
+ .driver = {
+ .name = "loongson3_cpufreq",
+ },
+ .id_table = cpufreq_id_table,
+};
+
+static int configure_cpufreq_info(void)
+{
+ int ret;
+ union smc_message msg;
+
+ msg.cmd = CMD_GET_VERSION;
+ msg.extra = 0;
+ msg.complete = 0;
+ ret = do_service_request(&msg);
+ if (ret < 0 || msg.val < 0x1)
+ return -EPERM;
+
+ msg.id = FEATURE_DVFS;
+ msg.cmd = CMD_SET_FEATURE;
+ msg.val = FEATURE_DVFS_ENABLE | FEATURE_DVFS_BOOST;
+ msg.extra = 0;
+ msg.complete = 0;
+ ret = do_service_request(&msg);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+static int __init cpufreq_init(void)
+{
+ int i, ret;
+
+ ret = platform_driver_register(&loongson3_platform_driver);
+ if (ret)
+ return ret;
+
+ ret = configure_cpufreq_info();
+ if (ret)
+ goto err;
+
+ for (i = 0; i < MAX_PACKAGES; i++)
+ mutex_init(&cpufreq_mutex[i]);
+
+ ret = cpufreq_register_driver(&loongson3_cpufreq_driver);
+ if (ret)
+ goto err;
+
+ pr_info("cpufreq: Loongson-3 CPU frequency driver.\n");
+
+ return 0;
+
+err:
+ platform_driver_unregister(&loongson3_platform_driver);
+ return ret;
+}
+
+static void __exit cpufreq_exit(void)
+{
+ cpufreq_unregister_driver(&loongson3_cpufreq_driver);
+ platform_driver_unregister(&loongson3_platform_driver);
+}
+
+module_init(cpufreq_init);
+module_exit(cpufreq_exit);
+
+MODULE_AUTHOR("Huacai Chen <[email protected]>");
+MODULE_DESCRIPTION("CPUFreq driver for Loongson-3 processors");
+MODULE_LICENSE("GPL");
--
2.43.0