diff options
Diffstat (limited to 'hw/ppc.c')
| -rw-r--r-- | hw/ppc.c | 175 |
1 files changed, 175 insertions, 0 deletions
@@ -28,6 +28,181 @@ void ppc_prep_init (int ram_size, int vga_ram_size, int boot_device, 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, |