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[71.163.245.5]) by smtp.googlemail.com with ESMTPSA id n14sm7303398qti.47.2021.08.09.12.16.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Aug 2021 12:16:09 -0700 (PDT) From: Thara Gopinath To: agross@kernel.org, bjorn.andersson@linaro.org, rui.zhang@intel.com, daniel.lezcano@linaro.org, viresh.kumar@linaro.org, rjw@rjwysocki.net, robh+dt@kernel.org Cc: steev@kali.org, tdas@codeaurora.org, mka@chromium.org, linux-arm-msm@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: [Patch v5 3/6] cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support Date: Mon, 9 Aug 2021 15:16:01 -0400 Message-Id: <20210809191605.3742979-4-thara.gopinath@linaro.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210809191605.3742979-1-thara.gopinath@linaro.org> References: <20210809191605.3742979-1-thara.gopinath@linaro.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Add interrupt support to notify the kernel of h/w initiated frequency throttling by LMh. Convey this to scheduler via thermal presssure interface. Signed-off-by: Thara Gopinath --- v4->v5: - Changed throttle_lock from a spinlock to mutex to take potential race between LMh de-init sequence and reenabling of interrupts/polling after a thermal throttle event. - Other cosmetic fixes as pointed out by Viresh. v3->v4: - Dropped devm_ versions of request_irq and free_irq as per comments on mailing list. - Introduced locking to prevent race between LMh de-init sequence and re-enabling of interrupts/polling after a thermal throttle event. - Moved the LMh de-init sequence to qcom_cpufreq_hw_lmh_exit as per Viresh's review comments - Code rearrangement as per Bjorn's review comments. - Moved the interrupt handling to threaded interrupt handling since Steev reported some scheduling while atomic bug on the mailing list. v2->v3: - Cosmetic fixes from review comments on the list. - Moved all LMh initializations to qcom_cpufreq_hw_lmh_init. - Added freeing of LMh interrupt and cancelling the polling worker to qcom_cpufreq_hw_cpu_exit as per Viresh's suggestion. - LMh interrupts are now tied to cpu dev and not cpufreq dev. This will be useful for further generation of SoCs where the same interrupt signals multiple cpu clusters. v1->v2: - Introduced qcom_cpufreq_hw_lmh_init to consolidate LMh related initializations as per Viresh's review comment. - Moved the piece of code restarting polling/re-enabling LMh interrupt to qcom_lmh_dcvs_notify therby simplifying isr and timer callback as per Viresh's suggestion. - Droped cpus from qcom_cpufreq_data and instead using cpus from cpufreq_policy in qcom_lmh_dcvs_notify as per Viresh's review comment. - Dropped dt property qcom,support-lmh as per Bjorn's suggestion. - Other minor/cosmetic fixes drivers/cpufreq/qcom-cpufreq-hw.c | 147 ++++++++++++++++++++++++++++++ 1 file changed, 147 insertions(+) diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c index f86859bf76f1..d9f6da99af3a 100644 --- a/drivers/cpufreq/qcom-cpufreq-hw.c +++ b/drivers/cpufreq/qcom-cpufreq-hw.c @@ -7,12 +7,14 @@ #include #include #include +#include #include #include #include #include #include #include +#include #define LUT_MAX_ENTRIES 40U #define LUT_SRC GENMASK(31, 30) @@ -22,10 +24,13 @@ #define CLK_HW_DIV 2 #define LUT_TURBO_IND 1 +#define HZ_PER_KHZ 1000 + struct qcom_cpufreq_soc_data { u32 reg_enable; u32 reg_freq_lut; u32 reg_volt_lut; + u32 reg_current_vote; u32 reg_perf_state; u8 lut_row_size; }; @@ -34,6 +39,16 @@ struct qcom_cpufreq_data { void __iomem *base; struct resource *res; const struct qcom_cpufreq_soc_data *soc_data; + + /* + * Mutex to synchronize between de-init sequence and re-starting LMh + * polling/interrupts + */ + struct mutex throttle_lock; + int throttle_irq; + bool cancel_throttle; + struct delayed_work throttle_work; + struct cpufreq_policy *policy; }; static unsigned long cpu_hw_rate, xo_rate; @@ -251,10 +266,92 @@ static void qcom_get_related_cpus(int index, struct cpumask *m) } } +static unsigned int qcom_lmh_get_throttle_freq(struct qcom_cpufreq_data *data) +{ + unsigned int val = readl_relaxed(data->base + data->soc_data->reg_current_vote); + + return (val & 0x3FF) * 19200; +} + +static void qcom_lmh_dcvs_notify(struct qcom_cpufreq_data *data) +{ + unsigned long max_capacity, capacity, freq_hz, throttled_freq; + struct cpufreq_policy *policy = data->policy; + int cpu = cpumask_first(policy->cpus); + struct device *dev = get_cpu_device(cpu); + struct dev_pm_opp *opp; + unsigned int freq; + + /* + * Get the h/w throttled frequency, normalize it using the + * registered opp table and use it to calculate thermal pressure. + */ + freq = qcom_lmh_get_throttle_freq(data); + freq_hz = freq * HZ_PER_KHZ; + + opp = dev_pm_opp_find_freq_floor(dev, &freq_hz); + if (IS_ERR(opp) && PTR_ERR(opp) == -ERANGE) + opp = dev_pm_opp_find_freq_ceil(dev, &freq_hz); + + throttled_freq = freq_hz / HZ_PER_KHZ; + + /* Update thermal pressure */ + + max_capacity = arch_scale_cpu_capacity(cpu); + capacity = mult_frac(max_capacity, throttled_freq, policy->cpuinfo.max_freq); + + /* Don't pass boost capacity to scheduler */ + if (capacity > max_capacity) + capacity = max_capacity; + + arch_set_thermal_pressure(policy->cpus, max_capacity - capacity); + + /* + * In the unlikely case policy is unregistered do not enable + * polling or h/w interrupt + */ + mutex_lock(&data->throttle_lock); + if (data->cancel_throttle) + goto out; + + /* + * If h/w throttled frequency is higher than what cpufreq has requested + * for, then stop polling and switch back to interrupt mechanism. + */ + if (throttled_freq >= qcom_cpufreq_hw_get(cpu)) + enable_irq(data->throttle_irq); + else + mod_delayed_work(system_highpri_wq, &data->throttle_work, + msecs_to_jiffies(10)); + +out: + mutex_unlock(&data->throttle_lock); +} + +static void qcom_lmh_dcvs_poll(struct work_struct *work) +{ + struct qcom_cpufreq_data *data; + + data = container_of(work, struct qcom_cpufreq_data, throttle_work.work); + qcom_lmh_dcvs_notify(data); +} + +static irqreturn_t qcom_lmh_dcvs_handle_irq(int irq, void *data) +{ + struct qcom_cpufreq_data *c_data = data; + + /* Disable interrupt and enable polling */ + disable_irq_nosync(c_data->throttle_irq); + qcom_lmh_dcvs_notify(c_data); + + return 0; +} + static const struct qcom_cpufreq_soc_data qcom_soc_data = { .reg_enable = 0x0, .reg_freq_lut = 0x110, .reg_volt_lut = 0x114, + .reg_current_vote = 0x704, .reg_perf_state = 0x920, .lut_row_size = 32, }; @@ -274,6 +371,51 @@ static const struct of_device_id qcom_cpufreq_hw_match[] = { }; MODULE_DEVICE_TABLE(of, qcom_cpufreq_hw_match); +static int qcom_cpufreq_hw_lmh_init(struct cpufreq_policy *policy, int index) +{ + struct qcom_cpufreq_data *data = policy->driver_data; + struct platform_device *pdev = cpufreq_get_driver_data(); + char irq_name[15]; + int ret; + + /* + * Look for LMh interrupt. If no interrupt line is specified / + * if there is an error, allow cpufreq to be enabled as usual. + */ + data->throttle_irq = platform_get_irq(pdev, index); + if (data->throttle_irq <= 0) + return data->throttle_irq == -EPROBE_DEFER ? -EPROBE_DEFER : 0; + + data->cancel_throttle = false; + data->policy = policy; + + mutex_init(&data->throttle_lock); + INIT_DEFERRABLE_WORK(&data->throttle_work, qcom_lmh_dcvs_poll); + + snprintf(irq_name, sizeof(irq_name), "dcvsh-irq-%u", policy->cpu); + ret = request_threaded_irq(data->throttle_irq, NULL, qcom_lmh_dcvs_handle_irq, + IRQF_ONESHOT, irq_name, data); + if (ret) { + dev_err(&pdev->dev, "Error registering %s: %d\n", irq_name, ret); + return 0; + } + + return 0; +} + +static void qcom_cpufreq_hw_lmh_exit(struct qcom_cpufreq_data *data) +{ + if (data->throttle_irq <= 0) + return; + + mutex_lock(&data->throttle_lock); + data->cancel_throttle = true; + mutex_unlock(&data->throttle_lock); + + cancel_delayed_work_sync(&data->throttle_work); + free_irq(data->throttle_irq, data); +} + static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy) { struct platform_device *pdev = cpufreq_get_driver_data(); @@ -370,6 +512,10 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy) dev_warn(cpu_dev, "failed to enable boost: %d\n", ret); } + ret = qcom_cpufreq_hw_lmh_init(policy, index); + if (ret) + goto error; + return 0; error: kfree(data); @@ -389,6 +535,7 @@ static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy) dev_pm_opp_remove_all_dynamic(cpu_dev); dev_pm_opp_of_cpumask_remove_table(policy->related_cpus); + qcom_cpufreq_hw_lmh_exit(data); kfree(policy->freq_table); kfree(data); iounmap(base);