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authorXiongfeng Wang <wangxiongfeng2@huawei.com>2019-02-17 11:54:14 +0800
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2019-02-18 11:27:42 +0100
commit1757d05f3112acc5c0cdbcccad3afdee99655bf9 (patch)
tree6fee7b7291a0f0191a1e0b54da6e80eaeaad46be /drivers/acpi/cppc_acpi.c
parenta9a22b570bd512eb1ed946042bb88f11ecccca0c (diff)
downloadlinux-1757d05f3112acc5c0cdbcccad3afdee99655bf9.tar.bz2
ACPI / CPPC: Add a helper to get desired performance
This patch add a helper to get the value of desired performance register. Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com> [ rjw: More white space ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/cppc_acpi.c')
-rw-r--r--drivers/acpi/cppc_acpi.c42
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index 217a782c3e55..1b207fca1420 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -1051,6 +1051,48 @@ 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