diff options
Diffstat (limited to 'src/cpu/x86')
| -rw-r--r-- | src/cpu/x86/Kconfig | 6 | ||||
| -rw-r--r-- | src/cpu/x86/mp_init.c | 107 |
2 files changed, 106 insertions, 7 deletions
diff --git a/src/cpu/x86/Kconfig b/src/cpu/x86/Kconfig index 3e56d721f5..2e233cc778 100644 --- a/src/cpu/x86/Kconfig +++ b/src/cpu/x86/Kconfig @@ -10,6 +10,12 @@ config PARALLEL_MP in parallel. It additionally provides a more flexible mechanism for sequencing the steps of bringing up the APs. +config PARALLEL_MP_AP_WORK + def_bool n + depends on PARALLEL_MP + help + Allow APs to do other work after initialization instead of going + to sleep. config UDELAY_IO bool diff --git a/src/cpu/x86/mp_init.c b/src/cpu/x86/mp_init.c index baa3599a94..c989963442 100644 --- a/src/cpu/x86/mp_init.c +++ b/src/cpu/x86/mp_init.c @@ -127,6 +127,7 @@ struct mp_flight_plan { struct mp_flight_record *records; }; +static int global_num_aps; static struct mp_flight_plan mp_info; struct cpu_map { @@ -185,6 +186,11 @@ static void ap_do_flight_plan(void) } } +static void park_this_cpu(void) +{ + stop_this_cpu(); +} + /* By the time APs call ap_init() caching has been setup, and microcode has * been loaded. */ static void asmlinkage ap_init(unsigned int cpu) @@ -210,7 +216,7 @@ static void asmlinkage ap_init(unsigned int cpu) ap_do_flight_plan(); /* Park the AP. */ - stop_this_cpu(); + park_this_cpu(); } static void setup_default_sipi_vector_params(struct sipi_params *sp) @@ -587,7 +593,6 @@ static void init_bsp(struct bus *cpu_bus) static int mp_init(struct bus *cpu_bus, struct mp_params *p) { int num_cpus; - int num_aps; atomic_t *ap_count; init_bsp(cpu_bus); @@ -621,11 +626,11 @@ static int mp_init(struct bus *cpu_bus, struct mp_params *p) wbinvd(); /* Start the APs providing number of APs and the cpus_entered field. */ - num_aps = p->num_cpus - 1; - if (start_aps(cpu_bus, num_aps, ap_count) < 0) { + global_num_aps = p->num_cpus - 1; + if (start_aps(cpu_bus, global_num_aps, ap_count) < 0) { mdelay(1000); printk(BIOS_DEBUG, "%d/%d eventually checked in?\n", - atomic_read(ap_count), num_aps); + atomic_read(ap_count), global_num_aps); return -1; } @@ -838,6 +843,94 @@ static void trigger_smm_relocation(void) mp_state.ops.per_cpu_smm_trigger(); } +static mp_callback_t ap_callbacks[CONFIG_MAX_CPUS]; + +static mp_callback_t read_callback(mp_callback_t *slot) +{ + return *(volatile mp_callback_t *)slot; +} + +static void store_callback(mp_callback_t *slot, mp_callback_t value) +{ + *(volatile mp_callback_t *)slot = value; +} + +static int run_ap_work(mp_callback_t func, long expire_us) +{ + int i; + int cpus_accepted; + struct stopwatch sw; + int cur_cpu = cpu_index(); + + if (!IS_ENABLED(CONFIG_PARALLEL_MP_AP_WORK)) { + printk(BIOS_ERR, "APs already parked. PARALLEL_MP_AP_WORK not selected.\n"); + return -1; + } + + /* Signal to all the APs to run the func. */ + for (i = 0; i < ARRAY_SIZE(ap_callbacks); i++) { + if (cur_cpu == i) + continue; + store_callback(&ap_callbacks[i], func); + } + mfence(); + + /* Wait for all the APs to signal back that call has been accepted. */ + stopwatch_init_usecs_expire(&sw, expire_us); + for (cpus_accepted = 0; !stopwatch_expired(&sw); cpus_accepted = 0) { + for (i = 0; i < ARRAY_SIZE(ap_callbacks); i++) { + if (cur_cpu == i) + continue; + if (read_callback(&ap_callbacks[i]) == NULL) + cpus_accepted++; + } + if (cpus_accepted == global_num_aps) + return 0; + } + + printk(BIOS_ERR, "AP call expired. %d/%d CPUs accepted.\n", + cpus_accepted, global_num_aps); + return -1; +} + +static void ap_wait_for_instruction(void) +{ + int cur_cpu = cpu_index(); + + if (!IS_ENABLED(CONFIG_PARALLEL_MP_AP_WORK)) + return; + + while (1) { + mp_callback_t func = read_callback(&ap_callbacks[cur_cpu]); + + if (func == NULL) { + asm ("pause"); + continue; + } + + store_callback(&ap_callbacks[cur_cpu], NULL); + mfence(); + func(); + } +} + +int mp_run_on_aps(void (*func)(void), long expire_us) +{ + return run_ap_work(func, expire_us); +} + +int mp_run_on_all_cpus(void (*func)(void), long expire_us) +{ + /* Run on BSP first. */ + func(); + return mp_run_on_aps(func, expire_us); +} + +int mp_park_aps(void) +{ + return mp_run_on_aps(park_this_cpu, 10 * USECS_PER_MSEC); +} + static struct mp_flight_record mp_steps[] = { /* Once the APs are up load the SMM handlers. */ MP_FR_BLOCK_APS(NULL, load_smm_handlers), @@ -845,8 +938,8 @@ static struct mp_flight_record mp_steps[] = { MP_FR_NOBLOCK_APS(trigger_smm_relocation, trigger_smm_relocation), /* Initialize each CPU through the driver framework. */ MP_FR_BLOCK_APS(mp_initialize_cpu, mp_initialize_cpu), - /* Wait for APs to finish everything else then let them park. */ - MP_FR_BLOCK_APS(NULL, NULL), + /* Wait for APs to finish then optionally start looking for work. */ + MP_FR_BLOCK_APS(ap_wait_for_instruction, NULL), }; static void fill_mp_state(struct mp_state *state, const struct mp_ops *ops) |