mips: use fallback for random_get_entropy() instead of just c0 random

[platform/kernel/linux-rpi.git] / arch / mips / include / asm / timex.h

diff --git a/arch/mips/include/asm/timex.h b/arch/mips/include/asm/timex.h
index 8026baf..2e10788 100644 (file)
--- a/arch/mips/include/asm/timex.h
+++ b/arch/mips/include/asm/timex.h
@@ -76,25 +76,24 @@ static inline cycles_t get_cycles(void)
        else
                return 0;       /* no usable counter */
 }
+#define get_cycles get_cycles
 
 /*
  * Like get_cycles - but where c0_count is not available we desperately
  * use c0_random in an attempt to get at least a little bit of entropy.
- *
- * R6000 and R6000A neither have a count register nor a random register.
- * That leaves no entropy source in the CPU itself.
  */
 static inline unsigned long random_get_entropy(void)
 {
-       unsigned int prid = read_c0_prid();
-       unsigned int imp = prid & PRID_IMP_MASK;
+       unsigned int c0_random;
 
-       if (can_use_mips_counter(prid))
+       if (can_use_mips_counter(read_c0_prid()))
                return read_c0_count();
-       else if (likely(imp != PRID_IMP_R6000 && imp != PRID_IMP_R6000A))
-               return read_c0_random();
+
+       if (cpu_has_3kex)
+               c0_random = (read_c0_random() >> 8) & 0x3f;
        else
-               return 0;       /* no usable register */
+               c0_random = read_c0_random() & 0x3f;
+       return (random_get_entropy_fallback() << 6) | (0x3f - c0_random);
 }
 #define random_get_entropy random_get_entropy