diff mbox series

[v3,05/20] target/mips: Move cpu_mips_get_random() with CP0 helpers

Message ID 20201010204319.3119239-6-f4bug@amsat.org
State New
Headers show
Series hw/mips: Set CPU frequency | expand

Commit Message

Philippe Mathieu-Daudé Oct. 10, 2020, 8:43 p.m. UTC
The get_random() helper uses the CP0_Wired register, which is
unrelated to the CP0_Count register use 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.

Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>
Signed-off-by: Philippe Mathieu-Daudé <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(-)

Comments

Luc Michel Oct. 12, 2020, 7:35 a.m. UTC | #1
On 22:43 Sat 10 Oct     , Philippe Mathieu-Daudé wrote:
> The get_random() helper uses the CP0_Wired register, which is

> unrelated to the CP0_Count register use as timer.

typo: used
> 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.

> 

> Reviewed-by: Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>

> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>


Reviewed-by: Luc Michel <luc@lmichel.fr>


> ---

>  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 7f159a9230c..087cabaa6d4 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

> 


--
diff mbox series

Patch

diff --git a/target/mips/internal.h b/target/mips/internal.h
index 7f159a9230c..087cabaa6d4 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)
 {