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path: root/drivers/cpufreq/cppc_cpufreq.c
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Diffstat (limited to 'drivers/cpufreq/cppc_cpufreq.c')
-rw-r--r--drivers/cpufreq/cppc_cpufreq.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index fd25c21cee72..2ae978d27e61 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -42,6 +42,66 @@
*/
static struct cppc_cpudata **all_cpu_data;
+struct cppc_workaround_oem_info {
+ char oem_id[ACPI_OEM_ID_SIZE +1];
+ char oem_table_id[ACPI_OEM_TABLE_ID_SIZE + 1];
+ u32 oem_revision;
+};
+
+static bool apply_hisi_workaround;
+
+static struct cppc_workaround_oem_info wa_info[] = {
+ {
+ .oem_id = "HISI ",
+ .oem_table_id = "HIP07 ",
+ .oem_revision = 0,
+ }, {
+ .oem_id = "HISI ",
+ .oem_table_id = "HIP08 ",
+ .oem_revision = 0,
+ }
+};
+
+static unsigned int cppc_cpufreq_perf_to_khz(struct cppc_cpudata *cpu,
+ unsigned int perf);
+
+/*
+ * HISI platform does not support delivered performance counter and
+ * reference performance counter. It can calculate the performance using the
+ * platform specific mechanism. We reuse the desired performance register to
+ * store the real performance calculated by the platform.
+ */
+static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpunum)
+{
+ struct cppc_cpudata *cpudata = all_cpu_data[cpunum];
+ u64 desired_perf;
+ int ret;
+
+ ret = cppc_get_desired_perf(cpunum, &desired_perf);
+ if (ret < 0)
+ return -EIO;
+
+ return cppc_cpufreq_perf_to_khz(cpudata, desired_perf);
+}
+
+static void cppc_check_hisi_workaround(void)
+{
+ struct acpi_table_header *tbl;
+ acpi_status status = AE_OK;
+ int i;
+
+ status = acpi_get_table(ACPI_SIG_PCCT, 0, &tbl);
+ if (ACPI_FAILURE(status) || !tbl)
+ return;
+
+ for (i = 0; i < ARRAY_SIZE(wa_info); i++) {
+ if (!memcmp(wa_info[i].oem_id, tbl->oem_id, ACPI_OEM_ID_SIZE) &&
+ !memcmp(wa_info[i].oem_table_id, tbl->oem_table_id, ACPI_OEM_TABLE_ID_SIZE) &&
+ wa_info[i].oem_revision == tbl->oem_revision)
+ apply_hisi_workaround = true;
+ }
+}
+
/* Callback function used to retrieve the max frequency from DMI */
static void cppc_find_dmi_mhz(const struct dmi_header *dm, void *private)
{
@@ -334,6 +394,9 @@ static unsigned int cppc_cpufreq_get_rate(unsigned int cpunum)
struct cppc_cpudata *cpu = all_cpu_data[cpunum];
int ret;
+ if (apply_hisi_workaround)
+ return hisi_cppc_cpufreq_get_rate(cpunum);
+
ret = cppc_get_perf_ctrs(cpunum, &fb_ctrs_t0);
if (ret)
return ret;
@@ -386,6 +449,8 @@ static int __init cppc_cpufreq_init(void)
goto out;
}
+ cppc_check_hisi_workaround();
+
ret = cpufreq_register_driver(&cppc_cpufreq_driver);
if (ret)
goto out;