Re: [PATCH v5 6/8] cpuidle: Add RISC-V SBI CPU idle driver
From: Samuel Holland <samuel@sholland.org>
Date: 2021-06-06 18:39:51
Also in:
linux-arm-kernel, linux-pm, linux-riscv, lkml
On 6/2/21 6:23 AM, Anup Patel wrote:
quoted hunk ↗ jump to hunk
The RISC-V SBI HSM extension provides HSM suspend call which can be used by Linux RISC-V to enter platform specific low-power state. This patch adds a CPU idle driver based on RISC-V SBI calls which will populate idle states from device tree and use SBI calls to entry these idle states. Signed-off-by: Anup Patel <redacted> --- MAINTAINERS | 7 + drivers/cpuidle/Kconfig | 5 + drivers/cpuidle/Kconfig.riscv | 15 + drivers/cpuidle/Makefile | 4 + drivers/cpuidle/cpuidle-sbi.c | 626 ++++++++++++++++++++++++++++++++++ 5 files changed, 657 insertions(+) create mode 100644 drivers/cpuidle/Kconfig.riscv create mode 100644 drivers/cpuidle/cpuidle-sbi.c ...diff --git a/drivers/cpuidle/cpuidle-sbi.c b/drivers/cpuidle/cpuidle-sbi.c new file mode 100644 index 000000000000..f743684d07de --- /dev/null +++ b/drivers/cpuidle/cpuidle-sbi.c@@ -0,0 +1,626 @@... + /* 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 int sbi_cpuidle_pd_power_off(struct generic_pm_domain *pd)
This function should be moved inside the CONFIG_DT_IDLE_GENPD block below. Otherwise it is defined but unused.
+{
+ 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;
+}
+
+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
+
+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;
...