[PULL 14/44] target/mips: Move cpu_mips_get_random() with CP0 helpers

["Philippe Mathieu-Daudé" <f4bug@amsat.org>]

The get_random() helper uses the CP0_Wired register, which is
unrelated to the CP0_Count register used as timer.
Commit e16fe40c872 ("Move the MIPS CPU timer in a separate file")
incorrectly moved this get_random() helper with timer specific
code. Move it back to generic CP0 helpers.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Reviewed-by: Luc Michel <luc@lmichel.fr>
Message-Id: <20201012095804.3335117-6-f4bug@amsat.org>
---
 target/mips/internal.h   |  2 +-
 target/mips/cp0_helper.c | 25 +++++++++++++++++++++++++
 target/mips/cp0_timer.c  | 25 -------------------------
 3 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/target/mips/internal.h b/target/mips/internal.h
index b811f547f38..dd8a7809b64 100644
--- a/target/mips/internal.h
+++ b/target/mips/internal.h
@@ -144,6 +144,7 @@ void r4k_helper_tlbr(CPUMIPSState *env);
 void r4k_helper_tlbinv(CPUMIPSState *env);
 void r4k_helper_tlbinvf(CPUMIPSState *env);
 void r4k_invalidate_tlb(CPUMIPSState *env, int idx, int use_extra);
+uint32_t cpu_mips_get_random(CPUMIPSState *env);
 
 void mips_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
                                     vaddr addr, unsigned size,
@@ -209,7 +210,6 @@ void cpu_state_reset(CPUMIPSState *s);
 void cpu_mips_realize_env(CPUMIPSState *env);
 
 /* cp0_timer.c */
-uint32_t cpu_mips_get_random(CPUMIPSState *env);
 uint32_t cpu_mips_get_count(CPUMIPSState *env);
 void cpu_mips_store_count(CPUMIPSState *env, uint32_t value);
 void cpu_mips_store_compare(CPUMIPSState *env, uint32_t value);
diff --git a/target/mips/cp0_helper.c b/target/mips/cp0_helper.c
index de64add038b..12143ac55b9 100644
--- a/target/mips/cp0_helper.c
+++ b/target/mips/cp0_helper.c
@@ -203,6 +203,31 @@ static void sync_c0_entryhi(CPUMIPSState *cpu, int tc)
     *tcst |= asid;
 }
 
+/* XXX: do not use a global */
+uint32_t cpu_mips_get_random(CPUMIPSState *env)
+{
+    static uint32_t seed = 1;
+    static uint32_t prev_idx;
+    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) % nb_rand_tlb + env->CP0_Wired;
+    } while (idx == prev_idx);
+    prev_idx = idx;
+    return idx;
+}
+
 /* CP0 helpers */
 target_ulong helper_mfc0_mvpcontrol(CPUMIPSState *env)
 {
diff --git a/target/mips/cp0_timer.c b/target/mips/cp0_timer.c
index bd7efb152dd..9c38e9da1c8 100644
--- a/target/mips/cp0_timer.c
+++ b/target/mips/cp0_timer.c
@@ -29,31 +29,6 @@
 
 #define TIMER_PERIOD 10 /* 10 ns period for 100 Mhz frequency */
 
-/* XXX: do not use a global */
-uint32_t cpu_mips_get_random(CPUMIPSState *env)
-{
-    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) % nb_rand_tlb + env->CP0_Wired;
-    } while (idx == prev_idx);
-    prev_idx = idx;
-    return idx;
-}
-
 /* MIPS R4K timer */
 static void cpu_mips_timer_update(CPUMIPSState *env)
 {
-- 
2.26.2