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Message-ID: <154402920660.88331.5729780274488650479@swboyd.mtv.corp.google.com>
Date: Wed, 05 Dec 2018 09:00:06 -0800
From: Stephen Boyd <sboyd@...nel.org>
To: Taniya Das <tdas@...eaurora.org>,
Viresh Kumar <viresh.kumar@...aro.org>
Cc: "Rafael J. Wysocki" <rjw@...ysocki.net>,
linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
Rajendra Nayak <rnayak@...eaurora.org>,
devicetree@...r.kernel.org, robh@...nel.org,
skannan@...eaurora.org, linux-arm-msm@...r.kernel.org,
evgreen@...gle.com
Subject: Re: [PATCH v11 2/2] cpufreq: qcom-hw: Add support for QCOM cpufreq HW driver
Quoting Viresh Kumar (2018-12-04 22:16:00)
> On 05-12-18, 09:07, Taniya Das wrote:
> > Hello Stephen, Viresh
> >
> > Thanks for the code and suggestions.
> >
> > Having a NR_DOMAINS '2' makes the driver not scalable for re-use.
>
> Sure, I didn't like it either and that wasn't really what I was suggesting in
> the first place. I didn't wanted to write the code myself and pass it on, but I
> have it now anyway :)
>
> It may have a bug or two in there, but compiles just fine and is rebased over
> your patch Taniya.
If we move the ioremap of registers to the cpufreq_driver::init path
then we need to unmap it on cpufreq_driver::exit. In fact, all the
devm_*() code in the init path needs to change to non-devm. Otherwise
it's a nice simplification!
> +static int qcom_cpufreq_hw_read_lut(struct device *dev,
> + struct cpufreq_policy *policy,
> + void __iomem *base)
> {
> u32 data, src, lval, i, core_count, prev_cc = 0, prev_freq = 0, freq;
> - unsigned int max_cores = cpumask_weight(&c->related_cpus);
> + unsigned int max_cores = cpumask_weight(policy->cpus);
> + struct cpufreq_frequency_table *table;
>
> - c->table = devm_kcalloc(dev, LUT_MAX_ENTRIES + 1,
> - sizeof(*c->table), GFP_KERNEL);
> - if (!c->table)
> + table = devm_kcalloc(dev, LUT_MAX_ENTRIES + 1,
> + sizeof(*table), GFP_KERNEL);
This one.
> + if (!table)
> return -ENOMEM;
>
> for (i = 0; i < LUT_MAX_ENTRIES; i++) {
> @@ -194,22 +154,29 @@ static void qcom_get_related_cpus(int index, struct cpumask *m)
> }
> }
>
> -static int qcom_cpu_resources_init(struct platform_device *pdev,
> - unsigned int cpu, int index,
> - unsigned long xo_rate,
> - unsigned long cpu_hw_rate)
> +static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
> {
> - struct cpufreq_qcom *c;
> + struct device *dev = &global_pdev->dev;
> + struct of_phandle_args args;
> + struct device_node *cpu_np;
> struct resource *res;
> - struct device *dev = &pdev->dev;
> void __iomem *base;
> - int ret, cpu_r;
> + int ret, index;
>
> - c = devm_kzalloc(dev, sizeof(*c), GFP_KERNEL);
> - if (!c)
> - return -ENOMEM;
> + cpu_np = of_cpu_device_node_get(policy->cpu);
> + if (!cpu_np)
> + return -EINVAL;
> +
> + ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
> + "#freq-domain-cells", 0, &args);
> + of_node_put(cpu_np);
>
> - res = platform_get_resource(pdev, IORESOURCE_MEM, index);
> + if (ret)
> + return ret;
> +
> + index = args.args[0];
> +
> + res = platform_get_resource(global_pdev, IORESOURCE_MEM, index);
> base = devm_ioremap_resource(dev, res);
And this one.
> if (IS_ERR(base))
> return PTR_ERR(base);
Here's a patch to squash in to fix those tiny problems. I left it as
devm_ioremap_resource() because that has all the nice features of
resource requesting inside and it didn't seem too bad to devm_iounmap()
on the exit path.
---------8<--------------
drivers/cpufreq/qcom-cpufreq-hw.c | 37 ++++++++++++++++++++++++++-----------
1 file changed, 26 insertions(+), 11 deletions(-)
diff --git a/drivers/cpufreq/qcom-cpufreq-hw.c b/drivers/cpufreq/qcom-cpufreq-hw.c
index bcf9bb37298a..1e865e216839 100644
--- a/drivers/cpufreq/qcom-cpufreq-hw.c
+++ b/drivers/cpufreq/qcom-cpufreq-hw.c
@@ -10,6 +10,7 @@
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
+#include <linux/slab.h>
#define LUT_MAX_ENTRIES 40U
#define LUT_SRC GENMASK(31, 30)
@@ -77,8 +78,7 @@ static int qcom_cpufreq_hw_read_lut(struct device *dev,
unsigned int max_cores = cpumask_weight(policy->cpus);
struct cpufreq_frequency_table *table;
- table = devm_kcalloc(dev, LUT_MAX_ENTRIES + 1,
- sizeof(*table), GFP_KERNEL);
+ table = kcalloc(LUT_MAX_ENTRIES + 1, sizeof(*table), GFP_KERNEL);
if (!table)
return -ENOMEM;
@@ -144,7 +144,7 @@ static void qcom_get_related_cpus(int index, struct cpumask *m)
ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
"#freq-domain-cells", 0,
- &args);
+ &args);
of_node_put(cpu_np);
if (ret < 0)
continue;
@@ -170,7 +170,6 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
ret = of_parse_phandle_with_args(cpu_np, "qcom,freq-domain",
"#freq-domain-cells", 0, &args);
of_node_put(cpu_np);
-
if (ret)
return ret;
@@ -184,13 +183,15 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
/* HW should be in enabled state to proceed */
if (!(readl_relaxed(base + REG_ENABLE) & 0x1)) {
dev_err(dev, "Domain-%d cpufreq hardware not enabled\n", index);
- return -ENODEV;
+ ret = -ENODEV;
+ goto error;
}
qcom_get_related_cpus(index, policy->cpus);
if (!cpumask_weight(policy->cpus)) {
dev_err(dev, "Domain-%d failed to get related CPUs\n", index);
- return -ENOENT;
+ ret = -ENOENT;
+ goto error;
}
policy->driver_data = base + REG_PERF_STATE;
@@ -198,11 +199,25 @@ static int qcom_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
ret = qcom_cpufreq_hw_read_lut(dev, policy, base);
if (ret) {
dev_err(dev, "Domain-%d failed to read LUT\n", index);
- return ret;
+ goto error;
}
policy->fast_switch_possible = true;
+ return 0;
+
+error:
+ devm_iounmap(dev, base);
+ return ret;
+}
+
+static int qcom_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
+{
+ void __iomem *base = policy->driver_data - REG_PERF_STATE;
+
+ kfree(policy->freq_table);
+ devm_iounmap(&global_pdev->dev, base);
+
return 0;
}
@@ -219,6 +234,7 @@ static struct cpufreq_driver cpufreq_qcom_hw_driver = {
.target_index = qcom_cpufreq_hw_target_index,
.get = qcom_cpufreq_hw_get,
.init = qcom_cpufreq_hw_cpu_init,
+ .exit = qcom_cpufreq_hw_cpu_exit,
.fast_switch = qcom_cpufreq_hw_fast_switch,
.name = "qcom-cpufreq-hw",
.attr = qcom_cpufreq_hw_attr,
@@ -248,12 +264,11 @@ static int qcom_cpufreq_hw_driver_probe(struct platform_device *pdev)
ret = cpufreq_register_driver(&cpufreq_qcom_hw_driver);
if (ret) {
dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
- return ret;
+ } else {
+ dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");
}
- dev_dbg(&pdev->dev, "QCOM CPUFreq HW driver initialized\n");
-
- return 0;
+ return ret;
}
static int qcom_cpufreq_hw_driver_remove(struct platform_device *pdev)
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