[PATCH 4.4 024/113] ACPI: CPPC: Return error if _CPC is invalid on a CPU

Greg Kroah-Hartman
2016-09-05T16:52:37Z

From: Hoan Tran <hotran@apm.com>

commit 8343c40d3de32ebfe8f48b043964e4ba0e7701f7 upstream.

Based on 8.4.7.1 section of ACPI 6.1 specification, if the platform
supports CPPC, the _CPC object must exist under all processor objects.
If cpc_desc_ptr pointer is invalid on any CPUs, acpi_get_psd_map()
should return error and CPPC cpufreq driver can not be registered.

Signed-off-by: Hoan Tran <hotran@apm.com>
Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/acpi/cppc_acpi.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -216,8 +216,10 @@ int acpi_get_psd_map(struct cpudata **al
continue;

cpc_ptr = per_cpu(cpc_desc_ptr, i);
- if (!cpc_ptr)
- continue;
+ if (!cpc_ptr) {
+ retval = -EFAULT;
+ goto err_ret;
+ }

pdomain = &(cpc_ptr->domain_info);
cpumask_set_cpu(i, pr->shared_cpu_map);
@@ -239,8 +241,10 @@ int acpi_get_psd_map(struct cpudata **al
continue;

match_cpc_ptr = per_cpu(cpc_desc_ptr, j);
- if (!match_cpc_ptr)
- continue;
+ if (!match_cpc_ptr) {
+ retval = -EFAULT;
+ goto err_ret;
+ }

match_pdomain = &(match_cpc_ptr->domain_info);
if (match_pdomain->domain != pdomain->domain)
@@ -270,8 +274,10 @@ int acpi_get_psd_map(struct cpudata **al
continue;

match_cpc_ptr = per_cpu(cpc_desc_ptr, j);
- if (!match_cpc_ptr)
- continue;
+ if (!match_cpc_ptr) {
+ retval = -EFAULT;
+ goto err_ret;
+ }

match_pdomain = &(match_cpc_ptr->domain_info);
if (match_pdomain->domain != pdomain->domain)