ARM: hw_breakpoint: Workaround for Cortex-A12/A17

It seems Cortex-A12/A17 do not report report watchpoint hit address
that matches the watchpoint set as ARM64. Add this workaround for
pass Android 8+ CTS bionic ptrace watchpoint_imprecise.

Change-Id: I22f08a081d1436931cbed4e8b340237799299737
Signed-off-by: Tao Huang <huangtao@rock-chips.com>

Author: rkhuangtao

arch/arm/kernel/hw_breakpoint.c

@@ -725,6 +725,20 @@ static void watchpoint_handler(unsigned long addr, unsigned int fsr,
 
 			/* Check if the watchpoint value matches. */
 			val = read_wb_reg(ARM_BASE_WVR + i);
+			/*
+			 * It seems Cortex-A12/A17 do not report report
+			 * watchpoint hit address that matches the watchpoint
+			 * set as ARM64.
+			 * Add this workaround for pass Android 8+ CTS
+			 * bionic ptrace watchpoint_imprecise.
+			 */
+			if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A12) {
+				unsigned long dist;
+
+				dist = val > addr ? val - addr : addr - val;
+				if (dist > 8)
+					goto unlock;
+			} else
 			if (val != (addr & ~alignment_mask))
 				goto unlock;