mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
628 lines
14 KiB
628 lines
14 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* RISC-V SBI CPU idle driver. |
|
* |
|
* Copyright (c) 2021 Western Digital Corporation or its affiliates. |
|
* Copyright (c) 2022 Ventana Micro Systems Inc. |
|
*/ |
|
|
|
#define pr_fmt(fmt) "cpuidle-riscv-sbi: " fmt |
|
|
|
#include <linux/cpuidle.h> |
|
#include <linux/cpumask.h> |
|
#include <linux/cpu_pm.h> |
|
#include <linux/cpu_cooling.h> |
|
#include <linux/kernel.h> |
|
#include <linux/module.h> |
|
#include <linux/of.h> |
|
#include <linux/of_device.h> |
|
#include <linux/slab.h> |
|
#include <linux/platform_device.h> |
|
#include <linux/pm_domain.h> |
|
#include <linux/pm_runtime.h> |
|
#include <asm/cpuidle.h> |
|
#include <asm/sbi.h> |
|
#include <asm/smp.h> |
|
#include <asm/suspend.h> |
|
|
|
#include "dt_idle_states.h" |
|
#include "dt_idle_genpd.h" |
|
|
|
struct sbi_cpuidle_data { |
|
u32 *states; |
|
struct device *dev; |
|
}; |
|
|
|
struct sbi_domain_state { |
|
bool available; |
|
u32 state; |
|
}; |
|
|
|
static DEFINE_PER_CPU_READ_MOSTLY(struct sbi_cpuidle_data, sbi_cpuidle_data); |
|
static DEFINE_PER_CPU(struct sbi_domain_state, domain_state); |
|
static bool sbi_cpuidle_use_osi; |
|
static bool sbi_cpuidle_use_cpuhp; |
|
static bool sbi_cpuidle_pd_allow_domain_state; |
|
|
|
static inline void sbi_set_domain_state(u32 state) |
|
{ |
|
struct sbi_domain_state *data = this_cpu_ptr(&domain_state); |
|
|
|
data->available = true; |
|
data->state = state; |
|
} |
|
|
|
static inline u32 sbi_get_domain_state(void) |
|
{ |
|
struct sbi_domain_state *data = this_cpu_ptr(&domain_state); |
|
|
|
return data->state; |
|
} |
|
|
|
static inline void sbi_clear_domain_state(void) |
|
{ |
|
struct sbi_domain_state *data = this_cpu_ptr(&domain_state); |
|
|
|
data->available = false; |
|
} |
|
|
|
static inline bool sbi_is_domain_state_available(void) |
|
{ |
|
struct sbi_domain_state *data = this_cpu_ptr(&domain_state); |
|
|
|
return data->available; |
|
} |
|
|
|
static int sbi_suspend_finisher(unsigned long suspend_type, |
|
unsigned long resume_addr, |
|
unsigned long opaque) |
|
{ |
|
struct sbiret ret; |
|
|
|
ret = sbi_ecall(SBI_EXT_HSM, SBI_EXT_HSM_HART_SUSPEND, |
|
suspend_type, resume_addr, opaque, 0, 0, 0); |
|
|
|
return (ret.error) ? sbi_err_map_linux_errno(ret.error) : 0; |
|
} |
|
|
|
static int sbi_suspend(u32 state) |
|
{ |
|
if (state & SBI_HSM_SUSP_NON_RET_BIT) |
|
return cpu_suspend(state, sbi_suspend_finisher); |
|
else |
|
return sbi_suspend_finisher(state, 0, 0); |
|
} |
|
|
|
static int sbi_cpuidle_enter_state(struct cpuidle_device *dev, |
|
struct cpuidle_driver *drv, int idx) |
|
{ |
|
u32 *states = __this_cpu_read(sbi_cpuidle_data.states); |
|
|
|
return CPU_PM_CPU_IDLE_ENTER_PARAM(sbi_suspend, idx, states[idx]); |
|
} |
|
|
|
static int __sbi_enter_domain_idle_state(struct cpuidle_device *dev, |
|
struct cpuidle_driver *drv, int idx, |
|
bool s2idle) |
|
{ |
|
struct sbi_cpuidle_data *data = this_cpu_ptr(&sbi_cpuidle_data); |
|
u32 *states = data->states; |
|
struct device *pd_dev = data->dev; |
|
u32 state; |
|
int ret; |
|
|
|
ret = cpu_pm_enter(); |
|
if (ret) |
|
return -1; |
|
|
|
/* Do runtime PM to manage a hierarchical CPU toplogy. */ |
|
rcu_irq_enter_irqson(); |
|
if (s2idle) |
|
dev_pm_genpd_suspend(pd_dev); |
|
else |
|
pm_runtime_put_sync_suspend(pd_dev); |
|
rcu_irq_exit_irqson(); |
|
|
|
if (sbi_is_domain_state_available()) |
|
state = sbi_get_domain_state(); |
|
else |
|
state = states[idx]; |
|
|
|
ret = sbi_suspend(state) ? -1 : idx; |
|
|
|
rcu_irq_enter_irqson(); |
|
if (s2idle) |
|
dev_pm_genpd_resume(pd_dev); |
|
else |
|
pm_runtime_get_sync(pd_dev); |
|
rcu_irq_exit_irqson(); |
|
|
|
cpu_pm_exit(); |
|
|
|
/* Clear the domain state to start fresh when back from idle. */ |
|
sbi_clear_domain_state(); |
|
return ret; |
|
} |
|
|
|
static int sbi_enter_domain_idle_state(struct cpuidle_device *dev, |
|
struct cpuidle_driver *drv, int idx) |
|
{ |
|
return __sbi_enter_domain_idle_state(dev, drv, idx, false); |
|
} |
|
|
|
static int sbi_enter_s2idle_domain_idle_state(struct cpuidle_device *dev, |
|
struct cpuidle_driver *drv, |
|
int idx) |
|
{ |
|
return __sbi_enter_domain_idle_state(dev, drv, idx, true); |
|
} |
|
|
|
static int sbi_cpuidle_cpuhp_up(unsigned int cpu) |
|
{ |
|
struct device *pd_dev = __this_cpu_read(sbi_cpuidle_data.dev); |
|
|
|
if (pd_dev) |
|
pm_runtime_get_sync(pd_dev); |
|
|
|
return 0; |
|
} |
|
|
|
static int sbi_cpuidle_cpuhp_down(unsigned int cpu) |
|
{ |
|
struct device *pd_dev = __this_cpu_read(sbi_cpuidle_data.dev); |
|
|
|
if (pd_dev) { |
|
pm_runtime_put_sync(pd_dev); |
|
/* Clear domain state to start fresh at next online. */ |
|
sbi_clear_domain_state(); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static void sbi_idle_init_cpuhp(void) |
|
{ |
|
int err; |
|
|
|
if (!sbi_cpuidle_use_cpuhp) |
|
return; |
|
|
|
err = cpuhp_setup_state_nocalls(CPUHP_AP_CPU_PM_STARTING, |
|
"cpuidle/sbi:online", |
|
sbi_cpuidle_cpuhp_up, |
|
sbi_cpuidle_cpuhp_down); |
|
if (err) |
|
pr_warn("Failed %d while setup cpuhp state\n", err); |
|
} |
|
|
|
static const struct of_device_id sbi_cpuidle_state_match[] = { |
|
{ .compatible = "riscv,idle-state", |
|
.data = sbi_cpuidle_enter_state }, |
|
{ }, |
|
}; |
|
|
|
static bool sbi_suspend_state_is_valid(u32 state) |
|
{ |
|
if (state > SBI_HSM_SUSPEND_RET_DEFAULT && |
|
state < SBI_HSM_SUSPEND_RET_PLATFORM) |
|
return false; |
|
if (state > SBI_HSM_SUSPEND_NON_RET_DEFAULT && |
|
state < SBI_HSM_SUSPEND_NON_RET_PLATFORM) |
|
return false; |
|
return true; |
|
} |
|
|
|
static int sbi_dt_parse_state_node(struct device_node *np, u32 *state) |
|
{ |
|
int err = of_property_read_u32(np, "riscv,sbi-suspend-param", state); |
|
|
|
if (err) { |
|
pr_warn("%pOF missing riscv,sbi-suspend-param property\n", np); |
|
return err; |
|
} |
|
|
|
if (!sbi_suspend_state_is_valid(*state)) { |
|
pr_warn("Invalid SBI suspend state %#x\n", *state); |
|
return -EINVAL; |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
static int sbi_dt_cpu_init_topology(struct cpuidle_driver *drv, |
|
struct sbi_cpuidle_data *data, |
|
unsigned int state_count, int cpu) |
|
{ |
|
/* Currently limit the hierarchical topology to be used in OSI mode. */ |
|
if (!sbi_cpuidle_use_osi) |
|
return 0; |
|
|
|
data->dev = dt_idle_attach_cpu(cpu, "sbi"); |
|
if (IS_ERR_OR_NULL(data->dev)) |
|
return PTR_ERR_OR_ZERO(data->dev); |
|
|
|
/* |
|
* Using the deepest state for the CPU to trigger a potential selection |
|
* of a shared state for the domain, assumes the domain states are all |
|
* deeper states. |
|
*/ |
|
drv->states[state_count - 1].enter = sbi_enter_domain_idle_state; |
|
drv->states[state_count - 1].enter_s2idle = |
|
sbi_enter_s2idle_domain_idle_state; |
|
sbi_cpuidle_use_cpuhp = true; |
|
|
|
return 0; |
|
} |
|
|
|
static int sbi_cpuidle_dt_init_states(struct device *dev, |
|
struct cpuidle_driver *drv, |
|
unsigned int cpu, |
|
unsigned int state_count) |
|
{ |
|
struct sbi_cpuidle_data *data = per_cpu_ptr(&sbi_cpuidle_data, cpu); |
|
struct device_node *state_node; |
|
struct device_node *cpu_node; |
|
u32 *states; |
|
int i, ret; |
|
|
|
cpu_node = of_cpu_device_node_get(cpu); |
|
if (!cpu_node) |
|
return -ENODEV; |
|
|
|
states = devm_kcalloc(dev, state_count, sizeof(*states), GFP_KERNEL); |
|
if (!states) { |
|
ret = -ENOMEM; |
|
goto fail; |
|
} |
|
|
|
/* Parse SBI specific details from state DT nodes */ |
|
for (i = 1; i < state_count; i++) { |
|
state_node = of_get_cpu_state_node(cpu_node, i - 1); |
|
if (!state_node) |
|
break; |
|
|
|
ret = sbi_dt_parse_state_node(state_node, &states[i]); |
|
of_node_put(state_node); |
|
|
|
if (ret) |
|
return ret; |
|
|
|
pr_debug("sbi-state %#x index %d\n", states[i], i); |
|
} |
|
if (i != state_count) { |
|
ret = -ENODEV; |
|
goto fail; |
|
} |
|
|
|
/* Initialize optional data, used for the hierarchical topology. */ |
|
ret = sbi_dt_cpu_init_topology(drv, data, state_count, cpu); |
|
if (ret < 0) |
|
return ret; |
|
|
|
/* Store states in the per-cpu struct. */ |
|
data->states = states; |
|
|
|
fail: |
|
of_node_put(cpu_node); |
|
|
|
return ret; |
|
} |
|
|
|
static void sbi_cpuidle_deinit_cpu(int cpu) |
|
{ |
|
struct sbi_cpuidle_data *data = per_cpu_ptr(&sbi_cpuidle_data, cpu); |
|
|
|
dt_idle_detach_cpu(data->dev); |
|
sbi_cpuidle_use_cpuhp = false; |
|
} |
|
|
|
static int sbi_cpuidle_init_cpu(struct device *dev, int cpu) |
|
{ |
|
struct cpuidle_driver *drv; |
|
unsigned int state_count = 0; |
|
int ret = 0; |
|
|
|
drv = devm_kzalloc(dev, sizeof(*drv), GFP_KERNEL); |
|
if (!drv) |
|
return -ENOMEM; |
|
|
|
drv->name = "sbi_cpuidle"; |
|
drv->owner = THIS_MODULE; |
|
drv->cpumask = (struct cpumask *)cpumask_of(cpu); |
|
|
|
/* RISC-V architectural WFI to be represented as state index 0. */ |
|
drv->states[0].enter = sbi_cpuidle_enter_state; |
|
drv->states[0].exit_latency = 1; |
|
drv->states[0].target_residency = 1; |
|
drv->states[0].power_usage = UINT_MAX; |
|
strcpy(drv->states[0].name, "WFI"); |
|
strcpy(drv->states[0].desc, "RISC-V WFI"); |
|
|
|
/* |
|
* If no DT idle states are detected (ret == 0) let the driver |
|
* initialization fail accordingly since there is no reason to |
|
* initialize the idle driver if only wfi is supported, the |
|
* default archictectural back-end already executes wfi |
|
* on idle entry. |
|
*/ |
|
ret = dt_init_idle_driver(drv, sbi_cpuidle_state_match, 1); |
|
if (ret <= 0) { |
|
pr_debug("HART%ld: failed to parse DT idle states\n", |
|
cpuid_to_hartid_map(cpu)); |
|
return ret ? : -ENODEV; |
|
} |
|
state_count = ret + 1; /* Include WFI state as well */ |
|
|
|
/* Initialize idle states from DT. */ |
|
ret = sbi_cpuidle_dt_init_states(dev, drv, cpu, state_count); |
|
if (ret) { |
|
pr_err("HART%ld: failed to init idle states\n", |
|
cpuid_to_hartid_map(cpu)); |
|
return ret; |
|
} |
|
|
|
ret = cpuidle_register(drv, NULL); |
|
if (ret) |
|
goto deinit; |
|
|
|
cpuidle_cooling_register(drv); |
|
|
|
return 0; |
|
deinit: |
|
sbi_cpuidle_deinit_cpu(cpu); |
|
return ret; |
|
} |
|
|
|
static void sbi_cpuidle_domain_sync_state(struct device *dev) |
|
{ |
|
/* |
|
* All devices have now been attached/probed to the PM domain |
|
* topology, hence it's fine to allow domain states to be picked. |
|
*/ |
|
sbi_cpuidle_pd_allow_domain_state = true; |
|
} |
|
|
|
#ifdef CONFIG_DT_IDLE_GENPD |
|
|
|
static int sbi_cpuidle_pd_power_off(struct generic_pm_domain *pd) |
|
{ |
|
struct genpd_power_state *state = &pd->states[pd->state_idx]; |
|
u32 *pd_state; |
|
|
|
if (!state->data) |
|
return 0; |
|
|
|
if (!sbi_cpuidle_pd_allow_domain_state) |
|
return -EBUSY; |
|
|
|
/* OSI mode is enabled, set the corresponding domain state. */ |
|
pd_state = state->data; |
|
sbi_set_domain_state(*pd_state); |
|
|
|
return 0; |
|
} |
|
|
|
struct sbi_pd_provider { |
|
struct list_head link; |
|
struct device_node *node; |
|
}; |
|
|
|
static LIST_HEAD(sbi_pd_providers); |
|
|
|
static int sbi_pd_init(struct device_node *np) |
|
{ |
|
struct generic_pm_domain *pd; |
|
struct sbi_pd_provider *pd_provider; |
|
struct dev_power_governor *pd_gov; |
|
int ret = -ENOMEM, state_count = 0; |
|
|
|
pd = dt_idle_pd_alloc(np, sbi_dt_parse_state_node); |
|
if (!pd) |
|
goto out; |
|
|
|
pd_provider = kzalloc(sizeof(*pd_provider), GFP_KERNEL); |
|
if (!pd_provider) |
|
goto free_pd; |
|
|
|
pd->flags |= GENPD_FLAG_IRQ_SAFE | GENPD_FLAG_CPU_DOMAIN; |
|
|
|
/* Allow power off when OSI is available. */ |
|
if (sbi_cpuidle_use_osi) |
|
pd->power_off = sbi_cpuidle_pd_power_off; |
|
else |
|
pd->flags |= GENPD_FLAG_ALWAYS_ON; |
|
|
|
/* Use governor for CPU PM domains if it has some states to manage. */ |
|
pd_gov = state_count > 0 ? &pm_domain_cpu_gov : NULL; |
|
|
|
ret = pm_genpd_init(pd, pd_gov, false); |
|
if (ret) |
|
goto free_pd_prov; |
|
|
|
ret = of_genpd_add_provider_simple(np, pd); |
|
if (ret) |
|
goto remove_pd; |
|
|
|
pd_provider->node = of_node_get(np); |
|
list_add(&pd_provider->link, &sbi_pd_providers); |
|
|
|
pr_debug("init PM domain %s\n", pd->name); |
|
return 0; |
|
|
|
remove_pd: |
|
pm_genpd_remove(pd); |
|
free_pd_prov: |
|
kfree(pd_provider); |
|
free_pd: |
|
dt_idle_pd_free(pd); |
|
out: |
|
pr_err("failed to init PM domain ret=%d %pOF\n", ret, np); |
|
return ret; |
|
} |
|
|
|
static void sbi_pd_remove(void) |
|
{ |
|
struct sbi_pd_provider *pd_provider, *it; |
|
struct generic_pm_domain *genpd; |
|
|
|
list_for_each_entry_safe(pd_provider, it, &sbi_pd_providers, link) { |
|
of_genpd_del_provider(pd_provider->node); |
|
|
|
genpd = of_genpd_remove_last(pd_provider->node); |
|
if (!IS_ERR(genpd)) |
|
kfree(genpd); |
|
|
|
of_node_put(pd_provider->node); |
|
list_del(&pd_provider->link); |
|
kfree(pd_provider); |
|
} |
|
} |
|
|
|
static int sbi_genpd_probe(struct device_node *np) |
|
{ |
|
struct device_node *node; |
|
int ret = 0, pd_count = 0; |
|
|
|
if (!np) |
|
return -ENODEV; |
|
|
|
/* |
|
* Parse child nodes for the "#power-domain-cells" property and |
|
* initialize a genpd/genpd-of-provider pair when it's found. |
|
*/ |
|
for_each_child_of_node(np, node) { |
|
if (!of_find_property(node, "#power-domain-cells", NULL)) |
|
continue; |
|
|
|
ret = sbi_pd_init(node); |
|
if (ret) |
|
goto put_node; |
|
|
|
pd_count++; |
|
} |
|
|
|
/* Bail out if not using the hierarchical CPU topology. */ |
|
if (!pd_count) |
|
goto no_pd; |
|
|
|
/* Link genpd masters/subdomains to model the CPU topology. */ |
|
ret = dt_idle_pd_init_topology(np); |
|
if (ret) |
|
goto remove_pd; |
|
|
|
return 0; |
|
|
|
put_node: |
|
of_node_put(node); |
|
remove_pd: |
|
sbi_pd_remove(); |
|
pr_err("failed to create CPU PM domains ret=%d\n", ret); |
|
no_pd: |
|
return ret; |
|
} |
|
|
|
#else |
|
|
|
static inline int sbi_genpd_probe(struct device_node *np) |
|
{ |
|
return 0; |
|
} |
|
|
|
#endif |
|
|
|
static int sbi_cpuidle_probe(struct platform_device *pdev) |
|
{ |
|
int cpu, ret; |
|
struct cpuidle_driver *drv; |
|
struct cpuidle_device *dev; |
|
struct device_node *np, *pds_node; |
|
|
|
/* Detect OSI support based on CPU DT nodes */ |
|
sbi_cpuidle_use_osi = true; |
|
for_each_possible_cpu(cpu) { |
|
np = of_cpu_device_node_get(cpu); |
|
if (np && |
|
of_find_property(np, "power-domains", NULL) && |
|
of_find_property(np, "power-domain-names", NULL)) { |
|
continue; |
|
} else { |
|
sbi_cpuidle_use_osi = false; |
|
break; |
|
} |
|
} |
|
|
|
/* Populate generic power domains from DT nodes */ |
|
pds_node = of_find_node_by_path("/cpus/power-domains"); |
|
if (pds_node) { |
|
ret = sbi_genpd_probe(pds_node); |
|
of_node_put(pds_node); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
/* Initialize CPU idle driver for each CPU */ |
|
for_each_possible_cpu(cpu) { |
|
ret = sbi_cpuidle_init_cpu(&pdev->dev, cpu); |
|
if (ret) { |
|
pr_debug("HART%ld: idle driver init failed\n", |
|
cpuid_to_hartid_map(cpu)); |
|
goto out_fail; |
|
} |
|
} |
|
|
|
/* Setup CPU hotplut notifiers */ |
|
sbi_idle_init_cpuhp(); |
|
|
|
pr_info("idle driver registered for all CPUs\n"); |
|
|
|
return 0; |
|
|
|
out_fail: |
|
while (--cpu >= 0) { |
|
dev = per_cpu(cpuidle_devices, cpu); |
|
drv = cpuidle_get_cpu_driver(dev); |
|
cpuidle_unregister(drv); |
|
sbi_cpuidle_deinit_cpu(cpu); |
|
} |
|
|
|
return ret; |
|
} |
|
|
|
static struct platform_driver sbi_cpuidle_driver = { |
|
.probe = sbi_cpuidle_probe, |
|
.driver = { |
|
.name = "sbi-cpuidle", |
|
.sync_state = sbi_cpuidle_domain_sync_state, |
|
}, |
|
}; |
|
|
|
static int __init sbi_cpuidle_init(void) |
|
{ |
|
int ret; |
|
struct platform_device *pdev; |
|
|
|
/* |
|
* The SBI HSM suspend function is only available when: |
|
* 1) SBI version is 0.3 or higher |
|
* 2) SBI HSM extension is available |
|
*/ |
|
if ((sbi_spec_version < sbi_mk_version(0, 3)) || |
|
sbi_probe_extension(SBI_EXT_HSM) <= 0) { |
|
pr_info("HSM suspend not available\n"); |
|
return 0; |
|
} |
|
|
|
ret = platform_driver_register(&sbi_cpuidle_driver); |
|
if (ret) |
|
return ret; |
|
|
|
pdev = platform_device_register_simple("sbi-cpuidle", |
|
-1, NULL, 0); |
|
if (IS_ERR(pdev)) { |
|
platform_driver_unregister(&sbi_cpuidle_driver); |
|
return PTR_ERR(pdev); |
|
} |
|
|
|
return 0; |
|
} |
|
device_initcall(sbi_cpuidle_init);
|
|
|