diff --git a/arch/x86/cpu/mp_init.c b/arch/x86/cpu/mp_init.c index 69a23829b9..dd6d6bfab7 100644 --- a/arch/x86/cpu/mp_init.c +++ b/arch/x86/cpu/mp_init.c @@ -54,12 +54,7 @@ struct mp_flight_plan { * callback */ struct mp_callback { - /** - * func() - Function to call on the AP - * - * @arg: Argument to pass - */ - void (*func)(void *arg); + mp_run_func func; void *arg; int logical_cpu_number; }; @@ -514,6 +509,70 @@ static void store_callback(struct mp_callback **slot, struct mp_callback *val) dmb(); } +/** + * run_ap_work() - Run a callback on selected APs + * + * This writes @callback to all APs and waits for them all to acknowledge it, + * Note that whether each AP actually calls the callback depends on the value + * of logical_cpu_number (see struct mp_callback). The logical CPU number is + * the CPU device's req->seq value. + * + * @callback: Callback information to pass to all APs + * @bsp: CPU device for the BSP + * @num_cpus: The number of CPUs in the system (= number of APs + 1) + * @expire_ms: Timeout to wait for all APs to finish, in milliseconds, or 0 for + * no timeout + * @return 0 if OK, -ETIMEDOUT if one or more APs failed to respond in time + */ +static int run_ap_work(struct mp_callback *callback, struct udevice *bsp, + int num_cpus, uint expire_ms) +{ + int cur_cpu = bsp->req_seq; + int num_aps = num_cpus - 1; /* number of non-BSPs to get this message */ + int cpus_accepted; + ulong start; + int i; + + if (!IS_ENABLED(CONFIG_SMP_AP_WORK)) { + printf("APs already parked. CONFIG_SMP_AP_WORK not enabled\n"); + return -ENOTSUPP; + } + + /* Signal to all the APs to run the func. */ + for (i = 0; i < num_cpus; i++) { + if (cur_cpu != i) + store_callback(&ap_callbacks[i], callback); + } + mfence(); + + /* Wait for all the APs to signal back that call has been accepted. */ + start = get_timer(0); + + do { + mdelay(1); + cpus_accepted = 0; + + for (i = 0; i < num_cpus; i++) { + if (cur_cpu == i) + continue; + if (!read_callback(&ap_callbacks[i])) + cpus_accepted++; + } + + if (expire_ms && get_timer(start) >= expire_ms) { + log(UCLASS_CPU, LOGL_CRIT, + "AP call expired; %d/%d CPUs accepted\n", + cpus_accepted, num_aps); + return -ETIMEDOUT; + } + } while (cpus_accepted != num_aps); + + /* Make sure we can see any data written by the APs */ + mfence(); + + return 0; +} + /** * ap_wait_for_instruction() - Wait for and process requests from the main CPU * @@ -573,6 +632,42 @@ static struct mp_flight_record mp_steps[] = { MP_FR_BLOCK_APS(ap_wait_for_instruction, NULL, NULL, NULL), }; +int mp_run_on_cpus(int cpu_select, mp_run_func func, void *arg) +{ + struct mp_callback lcb = { + .func = func, + .arg = arg, + .logical_cpu_number = cpu_select, + }; + struct udevice *dev; + int num_cpus; + int ret; + + ret = get_bsp(&dev, &num_cpus); + if (ret < 0) + return log_msg_ret("bsp", ret); + if (cpu_select == MP_SELECT_ALL || cpu_select == MP_SELECT_BSP || + cpu_select == ret) { + /* Run on BSP first */ + func(arg); + } + + if (!IS_ENABLED(CONFIG_SMP_AP_WORK) || + !(gd->flags & GD_FLG_SMP_READY)) { + /* Allow use of this function on the BSP only */ + if (cpu_select == MP_SELECT_BSP || !cpu_select) + return 0; + return -ENOTSUPP; + } + + /* Allow up to 1 second for all APs to finish */ + ret = run_ap_work(&lcb, dev, num_cpus, 1000 /* ms */); + if (ret) + return log_msg_ret("aps", ret); + + return 0; +} + int mp_init(void) { int num_aps, num_cpus; diff --git a/arch/x86/include/asm/mp.h b/arch/x86/include/asm/mp.h index 41b1575f4b..eb49e690f2 100644 --- a/arch/x86/include/asm/mp.h +++ b/arch/x86/include/asm/mp.h @@ -86,4 +86,37 @@ int mp_init(void); /* Set up additional CPUs */ int x86_mp_init(void); +/** + * mp_run_func() - Function to call on the AP + * + * @arg: Argument to pass + */ +typedef void (*mp_run_func)(void *arg); + +#if defined(CONFIG_SMP) && !CONFIG_IS_ENABLED(X86_64) +/** + * mp_run_on_cpus() - Run a function on one or all CPUs + * + * This does not return until all CPUs have completed the work + * + * Running on anything other than the boot CPU is only supported if + * CONFIG_SMP_AP_WORK is enabled + * + * @cpu_select: CPU to run on (its dev->req_seq value), or MP_SELECT_ALL for + * all, or MP_SELECT_BSP for BSP + * @func: Function to run + * @arg: Argument to pass to the function + * @return 0 on success, -ve on error + */ +int mp_run_on_cpus(int cpu_select, mp_run_func func, void *arg); +#else +static inline int mp_run_on_cpus(int cpu_select, mp_run_func func, void *arg) +{ + /* There is only one CPU, so just call the function here */ + func(arg); + + return 0; +} +#endif + #endif /* _X86_MP_H_ */