chickens: Enable NEX power gating on P-cores

It seems we missed this config all along.

Signed-off-by: Hector Martin <[email protected]>

Author: marcan

src/chickens.c

@@ -50,6 +50,12 @@ const char *init_cpu(void)
     else
         reg_set(SYS_IMP_APL_HID4, HID4_DISABLE_DC_MVA | HID4_DISABLE_DC_SW_L2_OPS);
 
+    /* Enable NEX powergating, the reset cycles might be overriden by chickens */
+    if (!is_ecore()) {
+        reg_mask(SYS_IMP_APL_HID13, HID13_RESET_CYCLES_MASK, HID13_RESET_CYCLES(12));
+        reg_set(SYS_IMP_APL_HID14, HID14_ENABLE_NEX_POWER_GATING);
+    }
+
     uint64_t midr = mrs(MIDR_EL1);
     int part = FIELD_GET(MIDR_PART, midr);
     int rev = (FIELD_GET(MIDR_REV_HIGH, midr) << 4) | FIELD_GET(MIDR_REV_LOW, midr);

src/cpu_regs.h

@@ -113,6 +113,9 @@
 #define HID13_RESET_CYCLES(x)       (((unsigned long)x) << 60)
 #define HID13_RESET_CYCLES_MASK     (0xFUL << 60)
 
+#define SYS_IMP_APL_HID14             sys_reg(3, 0, 15, 15, 0)
+#define HID14_ENABLE_NEX_POWER_GATING BIT(32)
+
 #define SYS_IMP_APL_HID16         sys_reg(3, 0, 15, 15, 2)
 #define HID16_AVL_UNK12           BIT(12)
 #define HID16_SPAREBIT0           BIT(56)