aboutsummaryrefslogtreecommitdiff
path: root/hw/ppc.c
blob: 3858952a57978e5b4fbd81a61893a56bad1ba628 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/*
 * QEMU generic PPC hardware System Emulator
 * 
 * Copyright (c) 2003-2004 Jocelyn Mayer
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "vl.h"

void ppc_prep_init (int ram_size, int vga_ram_size, int boot_device,
		    DisplayState *ds, const char **fd_filename, int snapshot,
		    const char *kernel_filename, const char *kernel_cmdline,
		    const char *initrd_filename);

/*****************************************************************************/
/* PPC time base and decrementer emulation */
//#define DEBUG_TB

struct ppc_tb_t {
    /* Time base management */
    int64_t  tb_offset;    /* Compensation               */
    uint32_t tb_freq;      /* TB frequency               */
    /* Decrementer management */
    uint64_t decr_next;    /* Tick for next decr interrupt  */
    struct QEMUTimer *decr_timer;
};

static inline uint64_t cpu_ppc_get_tb (ppc_tb_t *tb_env)
{
    /* TB time in tb periods */
    return muldiv64(qemu_get_clock(vm_clock) + tb_env->tb_offset,
		    tb_env->tb_freq, ticks_per_sec);
}

uint32_t cpu_ppc_load_tbl (CPUState *env)
{
    ppc_tb_t *tb_env = env->tb_env;
    uint64_t tb;

    tb = cpu_ppc_get_tb(tb_env);
#ifdef DEBUG_TB
    {
         static int last_time;
	 int now;
	 now = time(NULL);
	 if (last_time != now) {
	     last_time = now;
	     printf("%s: tb=0x%016lx %d %08lx\n",
                    __func__, tb, now, tb_env->tb_offset);
	 }
    }
#endif

    return tb & 0xFFFFFFFF;
}

uint32_t cpu_ppc_load_tbu (CPUState *env)
{
    ppc_tb_t *tb_env = env->tb_env;
    uint64_t tb;

    tb = cpu_ppc_get_tb(tb_env);
#ifdef DEBUG_TB
    printf("%s: tb=0x%016lx\n", __func__, tb);
#endif
    return tb >> 32;
}

static void cpu_ppc_store_tb (ppc_tb_t *tb_env, uint64_t value)
{
    tb_env->tb_offset = muldiv64(value, ticks_per_sec, tb_env->tb_freq)
        - qemu_get_clock(vm_clock);
#ifdef DEBUG_TB
    printf("%s: tb=0x%016lx offset=%08x\n", __func__, value);
#endif
}

void cpu_ppc_store_tbu (CPUState *env, uint32_t value)
{
    ppc_tb_t *tb_env = env->tb_env;

    cpu_ppc_store_tb(tb_env,
                     ((uint64_t)value << 32) | cpu_ppc_load_tbl(env));
}

void cpu_ppc_store_tbl (CPUState *env, uint32_t value)
{
    ppc_tb_t *tb_env = env->tb_env;

    cpu_ppc_store_tb(tb_env,
                     ((uint64_t)cpu_ppc_load_tbu(env) << 32) | value);
}

uint32_t cpu_ppc_load_decr (CPUState *env)
{
    ppc_tb_t *tb_env = env->tb_env;
    uint32_t decr;

    decr = muldiv64(tb_env->decr_next - qemu_get_clock(vm_clock),
                    tb_env->tb_freq, ticks_per_sec);
#ifdef DEBUG_TB
    printf("%s: 0x%08x\n", __func__, decr);
#endif

    return decr;
}

/* When decrementer expires,
 * all we need to do is generate or queue a CPU exception
 */
static inline void cpu_ppc_decr_excp (CPUState *env)
{
    /* Raise it */
#ifdef DEBUG_TB
    printf("raise decrementer exception\n");
#endif
    cpu_interrupt(env, CPU_INTERRUPT_TIMER);
}

static void _cpu_ppc_store_decr (CPUState *env, uint32_t decr,
                                 uint32_t value, int is_excp)
{
    ppc_tb_t *tb_env = env->tb_env;
    uint64_t now, next;

#ifdef DEBUG_TB
    printf("%s: 0x%08x => 0x%08x\n", __func__, decr, value);
#endif
    now = qemu_get_clock(vm_clock);
    next = now + muldiv64(value, ticks_per_sec, tb_env->tb_freq);
    if (is_excp)
        next += tb_env->decr_next - now;
    if (next == now)
	next++;
    tb_env->decr_next = next;
    /* Adjust timer */
    qemu_mod_timer(tb_env->decr_timer, next);
    /* If we set a negative value and the decrementer was positive,
     * raise an exception.
     */
    if ((value & 0x80000000) && !(decr & 0x80000000))
	cpu_ppc_decr_excp(env);
}

void cpu_ppc_store_decr (CPUState *env, uint32_t value)
{
    _cpu_ppc_store_decr(env, cpu_ppc_load_decr(env), value, 0);
}

static void cpu_ppc_decr_cb (void *opaque)
{
    _cpu_ppc_store_decr(opaque, 0x00000000, 0xFFFFFFFF, 1);
}

/* Set up (once) timebase frequency (in Hz) */
ppc_tb_t *cpu_ppc_tb_init (CPUState *env, uint32_t freq)
{
    ppc_tb_t *tb_env;

    tb_env = qemu_mallocz(sizeof(ppc_tb_t));
    if (tb_env == NULL)
        return NULL;
    env->tb_env = tb_env;
    if (tb_env->tb_freq == 0 || 1) {
	tb_env->tb_freq = freq;
	/* Create new timer */
	tb_env->decr_timer =
            qemu_new_timer(vm_clock, &cpu_ppc_decr_cb, env);
	/* There is a bug in  2.4 kernels:
	 * if a decrementer exception is pending when it enables msr_ee,
	 * it's not ready to handle it...
	 */
	_cpu_ppc_store_decr(env, 0xFFFFFFFF, 0xFFFFFFFF, 0);
    }

    return tb_env;
}

#if 0
/*****************************************************************************/
/* Handle system reset (for now, just stop emulation) */
void cpu_ppc_reset (CPUState *env)
{
    printf("Reset asked... Stop emulation\n");
    abort();
}
#endif

/*****************************************************************************/
void ppc_init (int ram_size, int vga_ram_size, int boot_device,
	       DisplayState *ds, const char **fd_filename, int snapshot,
	       const char *kernel_filename, const char *kernel_cmdline,
	       const char *initrd_filename)
{
    /* For now, only PREP is supported */
    return ppc_prep_init(ram_size, vga_ram_size, boot_device, ds, fd_filename,
			 snapshot, kernel_filename, kernel_cmdline,
			 initrd_filename);
}