ARM: hw_breakpoint: blacklist nexell CPUs

On s5p4418 nexell soc, the kernel crashes in arch_hw_breakpoint_init
when CONFIG_PERF_EVENTS option is enabled, taking an undefined
instruction trap. Blacklist nexell CPUs as like Scorpion CPUs.

Reference: ddc37832a134 ("ARM: 8634/1: hw_breakpoint: blacklist Scorpion CPUs")

Change-Id: I2aa6f43467d2369e1d08ae02dd1b64fc4410a701
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>

diff --git a/arch/arm/include/asm/cputype.h b/arch/arm/include/asm/cputype.h
index e9d04f4..ba52a71 100644 (file)
--- a/arch/arm/include/asm/cputype.h
+++ b/arch/arm/include/asm/cputype.h
@@ -84,6 +84,9 @@
 /* Qualcomm implemented cores */
 #define ARM_CPU_PART_SCORPION          0x510002d0
 
+/* Nexell implemented cores */
+#define ARM_CPU_PART_NEXELL            0x4100c090
+
 extern unsigned int processor_id;
 
 #ifdef CONFIG_CPU_CP15

diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index abcbea1..28a3eba 100644 (file)
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -1082,6 +1082,11 @@ static int __init arch_hw_breakpoint_init(void)
                return 0;
        }
 
+       if (read_cpuid_part() == ARM_CPU_PART_NEXELL) {
+               pr_info("NEXELL CPU detected. Hardware breakpoints and watchpoints disabled\n");
+               return 0;
+       }
+
        has_ossr = core_has_os_save_restore();
 
        /* Determine how many BRPs/WRPs are available. */