cpu_mips_get_random() function is used to generate a random index from
CP0.Wired to TLBSize-1 range. Current implementation avoids generating
the same as before value, hence the while loop. If the guest sets
CP0.Wired to TLBSize-1 (which actually does not sound to be very
practical) QEMU will get stuck in the loop infinitely as we always
generate the same index.
Signed-off-by: Leon Alrae <leon.alrae@imgtec.com>
Reviewed-by: Aurelien Jarno <aurelien@aurel32.net>
static uint32_t seed = 1;
static uint32_t prev_idx = 0;
uint32_t idx;
+ uint32_t nb_rand_tlb = env->tlb->nb_tlb - env->CP0_Wired;
+
+ if (nb_rand_tlb == 1) {
+ return env->tlb->nb_tlb - 1;
+ }
+
/* Don't return same value twice, so get another value */
do {
/* Use a simple algorithm of Linear Congruential Generator
* from ISO/IEC 9899 standard. */
seed = 1103515245 * seed + 12345;
- idx = (seed >> 16) % (env->tlb->nb_tlb - env->CP0_Wired) +
- env->CP0_Wired;
+ idx = (seed >> 16) % nb_rand_tlb + env->CP0_Wired;
} while (idx == prev_idx);
prev_idx = idx;
return idx;