From: Shawn Guo shawn.guo@linaro.org
commit 67fc209b527d023db4d087c68e44e9790aa089ef upstream.
Commit f17b3e44320b ("cpufreq: qcom-hw: Use devm_platform_ioremap_resource() to simplify code") introduces a regression on platforms using the driver, by failing to initialise a policy, when one is created post hotplug.
When all the CPUs of a policy are hoptplugged out, the call to .exit() and later to devm_iounmap() does not release the memory region that was requested during devm_platform_ioremap_resource(). Therefore, a subsequent call to .init() will result in the following error, which will prevent a new policy to be initialised:
[ 3395.915416] CPU4: shutdown [ 3395.938185] psci: CPU4 killed (polled 0 ms) [ 3399.071424] CPU5: shutdown [ 3399.094316] psci: CPU5 killed (polled 0 ms) [ 3402.139358] CPU6: shutdown [ 3402.161705] psci: CPU6 killed (polled 0 ms) [ 3404.742939] CPU7: shutdown [ 3404.765592] psci: CPU7 killed (polled 0 ms) [ 3411.492274] Detected VIPT I-cache on CPU4 [ 3411.492337] GICv3: CPU4: found redistributor 400 region 0:0x0000000017ae0000 [ 3411.492448] CPU4: Booted secondary processor 0x0000000400 [0x516f802d] [ 3411.503654] qcom-cpufreq-hw 17d43000.cpufreq: can't request region for resource [mem 0x17d45800-0x17d46bff]
With that being said, the original code was tricky and skipping memory region request intentionally to hide this issue. The true cause is that those devm_xxx() device managed functions shouldn't be used for cpufreq init/exit hooks, because &pdev->dev is alive across the hooks and will not trigger auto resource free-up. Let's drop the use of device managed functions and manually allocate/free resources, so that the issue can be fixed properly.
Cc: v5.10+ stable@vger.kernel.org # v5.10+ Fixes: f17b3e44320b ("cpufreq: qcom-hw: Use devm_platform_ioremap_resource() to simplify code") Suggested-by: Bjorn Andersson bjorn.andersson@linaro.org Signed-off-by: Shawn Guo shawn.guo@linaro.org Signed-off-by: Viresh Kumar viresh.kumar@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/cpufreq/qcom-cpufreq-hw.c | 40 ++++++++++++++++++++++++++++++-------- 1 file changed, 32 insertions(+), 8 deletions(-)
--- a/drivers/cpufreq/qcom-cpufreq-hw.c +++ b/drivers/cpufreq/qcom-cpufreq-hw.c @@ -32,6 +32,7 @@ struct qcom_cpufreq_soc_data {
struct qcom_cpufreq_data { void __iomem *base; + struct resource *res; const struct qcom_cpufreq_soc_data *soc_data; };
@@ -280,6 +281,7 @@ static int qcom_cpufreq_hw_cpu_init(stru struct of_phandle_args args; struct device_node *cpu_np; struct device *cpu_dev; + struct resource *res; void __iomem *base; struct qcom_cpufreq_data *data; int ret, index; @@ -303,18 +305,33 @@ static int qcom_cpufreq_hw_cpu_init(stru
index = args.args[0];
- base = devm_platform_ioremap_resource(pdev, index); - if (IS_ERR(base)) - return PTR_ERR(base); + res = platform_get_resource(pdev, IORESOURCE_MEM, index); + if (!res) { + dev_err(dev, "failed to get mem resource %d\n", index); + return -ENODEV; + } + + if (!request_mem_region(res->start, resource_size(res), res->name)) { + dev_err(dev, "failed to request resource %pR\n", res); + return -EBUSY; + }
- data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + base = ioremap(res->start, resource_size(res)); + if (IS_ERR(base)) { + dev_err(dev, "failed to map resource %pR\n", res); + ret = PTR_ERR(base); + goto release_region; + } + + data = kzalloc(sizeof(*data), GFP_KERNEL); if (!data) { ret = -ENOMEM; - goto error; + goto unmap_base; }
data->soc_data = of_device_get_match_data(&pdev->dev); data->base = base; + data->res = res;
/* HW should be in enabled state to proceed */ if (!(readl_relaxed(base + data->soc_data->reg_enable) & 0x1)) { @@ -349,7 +366,11 @@ static int qcom_cpufreq_hw_cpu_init(stru
return 0; error: - devm_iounmap(dev, base); + kfree(data); +unmap_base: + iounmap(data->base); +release_region: + release_mem_region(res->start, resource_size(res)); return ret; }
@@ -357,12 +378,15 @@ static int qcom_cpufreq_hw_cpu_exit(stru { struct device *cpu_dev = get_cpu_device(policy->cpu); struct qcom_cpufreq_data *data = policy->driver_data; - struct platform_device *pdev = cpufreq_get_driver_data(); + struct resource *res = data->res; + void __iomem *base = data->base;
dev_pm_opp_remove_all_dynamic(cpu_dev); dev_pm_opp_of_cpumask_remove_table(policy->related_cpus); kfree(policy->freq_table); - devm_iounmap(&pdev->dev, data->base); + kfree(data); + iounmap(base); + release_mem_region(res->start, resource_size(res));
return 0; }