root / hw / mips_timer.c @ cda9046b
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1 | 87ecb68b | pbrook | #include "hw.h" |
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2 | 87ecb68b | pbrook | #include "mips.h" |
3 | 87ecb68b | pbrook | #include "qemu-timer.h" |
4 | e16fe40c | ths | |
5 | ea86e4e6 | aurel32 | #define TIMER_FREQ 100 * 1000 * 1000 |
6 | ea86e4e6 | aurel32 | |
7 | e16fe40c | ths | /* XXX: do not use a global */
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8 | e16fe40c | ths | uint32_t cpu_mips_get_random (CPUState *env) |
9 | e16fe40c | ths | { |
10 | 59d94130 | aurel32 | static uint32_t lfsr = 1; |
11 | 59d94130 | aurel32 | static uint32_t prev_idx = 0; |
12 | e16fe40c | ths | uint32_t idx; |
13 | 59d94130 | aurel32 | /* Don't return same value twice, so get another value */
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14 | 59d94130 | aurel32 | do {
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15 | 59d94130 | aurel32 | lfsr = (lfsr >> 1) ^ (-(lfsr & 1u) & 0xd0000001u); |
16 | 59d94130 | aurel32 | idx = lfsr % (env->tlb->nb_tlb - env->CP0_Wired) + env->CP0_Wired; |
17 | 59d94130 | aurel32 | } while (idx == prev_idx);
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18 | 59d94130 | aurel32 | prev_idx = idx; |
19 | e16fe40c | ths | return idx;
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20 | e16fe40c | ths | } |
21 | e16fe40c | ths | |
22 | e16fe40c | ths | /* MIPS R4K timer */
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23 | e16fe40c | ths | uint32_t cpu_mips_get_count (CPUState *env) |
24 | e16fe40c | ths | { |
25 | 42532189 | ths | if (env->CP0_Cause & (1 << CP0Ca_DC)) |
26 | 42532189 | ths | return env->CP0_Count;
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27 | 42532189 | ths | else
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28 | 42532189 | ths | return env->CP0_Count +
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29 | 42532189 | ths | (uint32_t)muldiv64(qemu_get_clock(vm_clock), |
30 | ea86e4e6 | aurel32 | TIMER_FREQ, ticks_per_sec); |
31 | e16fe40c | ths | } |
32 | e16fe40c | ths | |
33 | ea86e4e6 | aurel32 | static void cpu_mips_timer_update(CPUState *env) |
34 | e16fe40c | ths | { |
35 | e16fe40c | ths | uint64_t now, next; |
36 | ea86e4e6 | aurel32 | uint32_t wait; |
37 | 39d51eb8 | ths | |
38 | e16fe40c | ths | now = qemu_get_clock(vm_clock); |
39 | ea86e4e6 | aurel32 | wait = env->CP0_Compare - env->CP0_Count - |
40 | ea86e4e6 | aurel32 | (uint32_t)muldiv64(now, TIMER_FREQ, ticks_per_sec); |
41 | ea86e4e6 | aurel32 | next = now + muldiv64(wait, ticks_per_sec, TIMER_FREQ); |
42 | e16fe40c | ths | qemu_mod_timer(env->timer, next); |
43 | e16fe40c | ths | } |
44 | e16fe40c | ths | |
45 | ea86e4e6 | aurel32 | void cpu_mips_store_count (CPUState *env, uint32_t count)
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46 | e16fe40c | ths | { |
47 | 3529b538 | ths | if (env->CP0_Cause & (1 << CP0Ca_DC)) |
48 | ea86e4e6 | aurel32 | env->CP0_Count = count; |
49 | ea86e4e6 | aurel32 | else {
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50 | ea86e4e6 | aurel32 | /* Store new count register */
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51 | ea86e4e6 | aurel32 | env->CP0_Count = |
52 | ea86e4e6 | aurel32 | count - (uint32_t)muldiv64(qemu_get_clock(vm_clock), |
53 | ea86e4e6 | aurel32 | TIMER_FREQ, ticks_per_sec); |
54 | ea86e4e6 | aurel32 | /* Update timer timer */
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55 | ea86e4e6 | aurel32 | cpu_mips_timer_update(env); |
56 | ea86e4e6 | aurel32 | } |
57 | e16fe40c | ths | } |
58 | e16fe40c | ths | |
59 | e16fe40c | ths | void cpu_mips_store_compare (CPUState *env, uint32_t value)
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60 | e16fe40c | ths | { |
61 | 3529b538 | ths | env->CP0_Compare = value; |
62 | ea86e4e6 | aurel32 | if (!(env->CP0_Cause & (1 << CP0Ca_DC))) |
63 | ea86e4e6 | aurel32 | cpu_mips_timer_update(env); |
64 | ea86e4e6 | aurel32 | if (env->insn_flags & ISA_MIPS32R2)
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65 | 39d51eb8 | ths | env->CP0_Cause &= ~(1 << CP0Ca_TI);
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66 | 42532189 | ths | qemu_irq_lower(env->irq[(env->CP0_IntCtl >> CP0IntCtl_IPTI) & 0x7]);
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67 | 42532189 | ths | } |
68 | 42532189 | ths | |
69 | 42532189 | ths | void cpu_mips_start_count(CPUState *env)
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70 | 42532189 | ths | { |
71 | 42532189 | ths | cpu_mips_store_count(env, env->CP0_Count); |
72 | 42532189 | ths | } |
73 | 42532189 | ths | |
74 | 42532189 | ths | void cpu_mips_stop_count(CPUState *env)
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75 | 42532189 | ths | { |
76 | 42532189 | ths | /* Store the current value */
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77 | 42532189 | ths | env->CP0_Count += (uint32_t)muldiv64(qemu_get_clock(vm_clock), |
78 | ea86e4e6 | aurel32 | TIMER_FREQ, ticks_per_sec); |
79 | e16fe40c | ths | } |
80 | e16fe40c | ths | |
81 | e16fe40c | ths | static void mips_timer_cb (void *opaque) |
82 | e16fe40c | ths | { |
83 | e16fe40c | ths | CPUState *env; |
84 | e16fe40c | ths | |
85 | e16fe40c | ths | env = opaque; |
86 | e16fe40c | ths | #if 0
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87 | 93fcfe39 | aliguori | qemu_log("%s\n", __func__);
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88 | e16fe40c | ths | #endif
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89 | 42532189 | ths | |
90 | 42532189 | ths | if (env->CP0_Cause & (1 << CP0Ca_DC)) |
91 | 42532189 | ths | return;
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92 | 42532189 | ths | |
93 | 2e70f6ef | pbrook | /* ??? This callback should occur when the counter is exactly equal to
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94 | 2e70f6ef | pbrook | the comparator value. Offset the count by one to avoid immediately
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95 | 2e70f6ef | pbrook | retriggering the callback before any virtual time has passed. */
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96 | 2e70f6ef | pbrook | env->CP0_Count++; |
97 | ea86e4e6 | aurel32 | cpu_mips_timer_update(env); |
98 | 2e70f6ef | pbrook | env->CP0_Count--; |
99 | ea86e4e6 | aurel32 | if (env->insn_flags & ISA_MIPS32R2)
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100 | 39d51eb8 | ths | env->CP0_Cause |= 1 << CP0Ca_TI;
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101 | 42532189 | ths | qemu_irq_raise(env->irq[(env->CP0_IntCtl >> CP0IntCtl_IPTI) & 0x7]);
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102 | e16fe40c | ths | } |
103 | e16fe40c | ths | |
104 | e16fe40c | ths | void cpu_mips_clock_init (CPUState *env)
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105 | e16fe40c | ths | { |
106 | e16fe40c | ths | env->timer = qemu_new_timer(vm_clock, &mips_timer_cb, env); |
107 | e16fe40c | ths | env->CP0_Compare = 0;
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108 | ea86e4e6 | aurel32 | cpu_mips_store_count(env, 1);
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109 | e16fe40c | ths | } |