arm64: platform: tegra: detect cpu using MIDR

This patch modifies the CPU detection macros
so that CPUs are identified by reading the
MIDR register value from per_cpu cpuinfo struct
rather than determining based on which cluster
they belong to.

Bug 1827294

Change-Id: I82eb452d6fc80db9ddaa5cfa9afdee50e3079a10
Signed-off-by: Rohit Khanna <rokhanna@nvidia.com>
Reviewed-on: http://git-master/r/1301621
GVS: Gerrit_Virtual_Submit
Reviewed-by: Alexander Van Brunt <avanbrunt@nvidia.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/include/linux/platform/tegra/tegra18_cpu_map.h b/include/linux/platform/tegra/tegra18_cpu_map.h
index 826498c20..77773e8e8 100644
--- a/include/linux/platform/tegra/tegra18_cpu_map.h
+++ b/include/linux/platform/tegra/tegra18_cpu_map.h
@@ -2,6 +2,12 @@
 #include <asm/cputype.h>
 #include <asm/cpu.h>
 #include <asm/smp_plat.h>
+#include <asm/cputype.h>
+
+/* MIDR Variant and Revision masked*/
+#define MIDR_CPU_MASK           0xFF0FFFF0
+#define MIDR_CPU_DENVER2        0x4E0F0030
+#define MIDR_CPU_A57            0x410FD070
 
 static inline u8 tegra18_logical_to_cluster(u8 cpu) {
         return MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 1);
@@ -11,14 +17,18 @@ static inline u8 tegra18_logical_to_cpu(u8 cpu) {
         return MPIDR_AFFINITY_LEVEL(cpu_logical_map(cpu), 0);
 }
 
+/* check if CPU is Denver2 */
 static inline int tegra18_is_cpu_denver(u8 cpu)
 {
-        return tegra18_logical_to_cluster(cpu) == 0;
+        struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, cpu);
+        return ((cpuinfo->reg_midr & MIDR_CPU_MASK) == MIDR_CPU_DENVER2);
 }
 
+/* check if CPU is A57 */
 static inline int tegra18_is_cpu_arm(u8 cpu)
 {
-        return tegra18_logical_to_cluster(cpu) == 1;
+        struct cpuinfo_arm64 *cpuinfo = &per_cpu(cpu_data, cpu);
+        return ((cpuinfo->reg_midr & MIDR_CPU_MASK) == MIDR_CPU_A57);
 }
 
 static inline int tegra18_logical_to_physical_cpu(u8 cpu)