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target/mips: Move cpu_mips_get_random() with CP0 helpers

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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>
This commit is contained in:
Philippe Mathieu-Daudé 2020-10-12 11:57:48 +02:00
parent 88a844545e
commit 2dc29222a6
3 changed files with 26 additions and 26 deletions
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25
target/mips/cp0_helper.c
View File

@ -203,6 +203,31 @@ static void sync_c0_entryhi(CPUMIPSState *cpu, int tc)
*tcst |= asid; *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 */ /* CP0 helpers */
target_ulong helper_mfc0_mvpcontrol(CPUMIPSState *env) target_ulong helper_mfc0_mvpcontrol(CPUMIPSState *env)
{ {

25
target/mips/cp0_timer.c
View File

@ -29,31 +29,6 @@
#define TIMER_PERIOD 10 /* 10 ns period for 100 Mhz frequency */ #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 */ /* MIPS R4K timer */
static void cpu_mips_timer_update(CPUMIPSState *env) static void cpu_mips_timer_update(CPUMIPSState *env)
{ {

2
target/mips/internal.h
View File

@ -144,6 +144,7 @@ void r4k_helper_tlbr(CPUMIPSState *env);
void r4k_helper_tlbinv(CPUMIPSState *env); void r4k_helper_tlbinv(CPUMIPSState *env);
void r4k_helper_tlbinvf(CPUMIPSState *env); void r4k_helper_tlbinvf(CPUMIPSState *env);
void r4k_invalidate_tlb(CPUMIPSState *env, int idx, int use_extra); 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, void mips_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
vaddr addr, unsigned size, vaddr addr, unsigned size,
@ -209,7 +210,6 @@ void cpu_state_reset(CPUMIPSState *s);
void cpu_mips_realize_env(CPUMIPSState *env); void cpu_mips_realize_env(CPUMIPSState *env);
/* cp0_timer.c */ /* cp0_timer.c */
uint32_t cpu_mips_get_random(CPUMIPSState *env);
uint32_t cpu_mips_get_count(CPUMIPSState *env); uint32_t cpu_mips_get_count(CPUMIPSState *env);
void cpu_mips_store_count(CPUMIPSState *env, uint32_t value); void cpu_mips_store_count(CPUMIPSState *env, uint32_t value);
void cpu_mips_store_compare(CPUMIPSState *env, uint32_t value); void cpu_mips_store_compare(CPUMIPSState *env, uint32_t value);