[PATCH v3 1/2] ACPI / CPPC: Add a helper to get desired performance

From: Xiongfeng Wang
Date: Sat Feb 16 2019 - 22:55:34 EST


This patch add a helper to get the value of desired performance
register.

Signed-off-by: Xiongfeng Wang <wangxiongfeng2@xxxxxxxxxx>
---
drivers/acpi/cppc_acpi.c | 39 +++++++++++++++++++++++++++++++++++++++
include/acpi/cppc_acpi.h | 1 +
2 files changed, 40 insertions(+)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 217a782..231d447 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1051,6 +1051,45 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
}

/**
+ * cppc_get_desired_perf - Get the value of desired performance register.
+ * @cpunum: CPU from which to get desired performance.
+ * @desired_perf: address of a variable to store the returned desired performance
+ *
+ * Return: 0 for success, -EIO otherwise.
+ */
+int cppc_get_desired_perf(int cpunum, u64 *desired_perf)
+{
+ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
+ int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum);
+ struct cpc_register_resource *desired_reg;
+ struct cppc_pcc_data *pcc_ss_data = NULL;
+
+ desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF];
+
+ if (CPC_IN_PCC(desired_reg)) {
+ int ret = 0;
+
+ if (pcc_ss_id < 0)
+ return -EIO;
+ pcc_ss_data = pcc_data[pcc_ss_id];
+
+ down_write(&pcc_ss_data->pcc_lock);
+ if (send_pcc_cmd(pcc_ss_id, CMD_READ) >= 0)
+ cpc_read(cpunum, desired_reg, desired_perf);
+ else
+ ret = -EIO;
+ up_write(&pcc_ss_data->pcc_lock);
+
+ return ret;
+ }
+
+ cpc_read(cpunum, desired_reg, desired_perf);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(cppc_get_desired_perf);
+
+/**
* cppc_get_perf_caps - Get a CPUs performance capabilities.
* @cpunum: CPU from which to get capabilities info.
* @perf_caps: ptr to cppc_perf_caps. See cppc_acpi.h
diff --git a/include/acpi/cppc_acpi.h b/include/acpi/cppc_acpi.h
index 4f34734..ba6fd72 100644
--- a/include/acpi/cppc_acpi.h
+++ b/include/acpi/cppc_acpi.h
@@ -137,6 +137,7 @@ struct cppc_cpudata {
cpumask_var_t shared_cpu_map;
};

+extern int cppc_get_desired_perf(int cpunum, u64 *desired_perf);
extern int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs);
extern int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls);
extern int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps);
--
1.7.12.4