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Diffstat (limited to 'roms/u-boot/arch/x86/include/asm/mp.h')
| -rw-r--r-- | roms/u-boot/arch/x86/include/asm/mp.h | 195 |
1 files changed, 195 insertions, 0 deletions
diff --git a/roms/u-boot/arch/x86/include/asm/mp.h b/roms/u-boot/arch/x86/include/asm/mp.h new file mode 100644 index 000000000..1a3ae8e39 --- /dev/null +++ b/roms/u-boot/arch/x86/include/asm/mp.h @@ -0,0 +1,195 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2015 Google, Inc + * + * Taken from coreboot file of the same name + */ + +#ifndef _X86_MP_H_ +#define _X86_MP_H_ + +#include <asm/atomic.h> +#include <asm/cache.h> + +struct udevice; + +enum { + /* Indicates that the function should run on all CPUs */ + MP_SELECT_ALL = -1, + + /* Run on boot CPUs */ + MP_SELECT_BSP = -2, + + /* Run on non-boot CPUs */ + MP_SELECT_APS = -3, +}; + +typedef int (*mp_callback_t)(struct udevice *cpu, void *arg); + +/* + * A mp_flight_record details a sequence of calls for the APs to perform + * along with the BSP to coordinate sequencing. Each flight record either + * provides a barrier for each AP before calling the callback or the APs + * are allowed to perform the callback without waiting. Regardless, each + * record has the cpus_entered field incremented for each record. When + * the BSP observes that the cpus_entered matches the number of APs + * the bsp_call is called with bsp_arg and upon returning releases the + * barrier allowing the APs to make further progress. + * + * Note that ap_call() and bsp_call() can be NULL. In the NULL case the + * callback will just not be called. + * + * @barrier: Ensures that the BSP and AP don't run the flight record at the same + * time + * @cpus_entered: Counts the number of APs that have run this record + * @ap_call: Function for the APs to call + * @ap_arg: Argument to pass to @ap_call + * @bsp_call: Function for the BSP to call + * @bsp_arg: Argument to pass to @bsp_call + */ +struct mp_flight_record { + atomic_t barrier; + atomic_t cpus_entered; + mp_callback_t ap_call; + void *ap_arg; + mp_callback_t bsp_call; + void *bsp_arg; +} __attribute__((aligned(ARCH_DMA_MINALIGN))); + +#define MP_FLIGHT_RECORD(barrier_, ap_func_, ap_arg_, bsp_func_, bsp_arg_) \ + { \ + .barrier = ATOMIC_INIT(barrier_), \ + .cpus_entered = ATOMIC_INIT(0), \ + .ap_call = ap_func_, \ + .ap_arg = ap_arg_, \ + .bsp_call = bsp_func_, \ + .bsp_arg = bsp_arg_, \ + } + +#define MP_FR_BLOCK_APS(ap_func, ap_arg, bsp_func, bsp_arg) \ + MP_FLIGHT_RECORD(0, ap_func, ap_arg, bsp_func, bsp_arg) + +#define MP_FR_NOBLOCK_APS(ap_func, ap_arg, bsp_func, bsp_arg) \ + MP_FLIGHT_RECORD(1, ap_func, ap_arg, bsp_func, bsp_arg) + +/* + * mp_init() will set up the SIPI vector and bring up the APs according to + * mp_params. Each flight record will be executed according to the plan. Note + * that the MP infrastructure uses SMM default area without saving it. It's + * up to the chipset or mainboard to either e820 reserve this area or save this + * region prior to calling mp_init() and restoring it after mp_init returns. + * + * At the time mp_init() is called the MTRR MSRs are mirrored into APs then + * caching is enabled before running the flight plan. + * + * The MP init has the following properties: + * 1. APs are brought up in parallel. + * 2. The ordering of cpu number and APIC ids is not deterministic. + * Therefore, one cannot rely on this property or the order of devices in + * the device tree unless the chipset or mainboard know the APIC ids + * a priori. + * + * mp_init() returns < 0 on error, 0 on success. + */ +int mp_init(void); + +/** + * x86_mp_init() - Set up additional CPUs + * + * @returns < 0 on error, 0 on success. + */ +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 CONFIG_IS_ENABLED(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_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); + +/** + * mp_park_aps() - Park the APs ready for the OS + * + * This halts all CPUs except the main one, ready for the OS to use them + * + * @return 0 if OK, -ve on error + */ +int mp_park_aps(void); + +/** + * mp_first_cpu() - Get the first CPU to process, from a selection + * + * This is used to iterate through selected CPUs. Call this function first, then + * call mp_next_cpu() repeatedly (with the same @cpu_select) until it returns + * -EFBIG. + * + * @cpu_select: Selected CPUs (either a CPU number or MP_SELECT_...) + * @return next CPU number to run on (e.g. 0) + */ +int mp_first_cpu(int cpu_select); + +/** + * mp_next_cpu() - Get the next CPU to process, from a selection + * + * This is used to iterate through selected CPUs. After first calling + * mp_first_cpu() once, call this function repeatedly until it returns -EFBIG. + * + * The value of @cpu_select must be the same for all calls and must match the + * value passed to mp_first_cpu(), otherwise the behaviour is undefined. + * + * @cpu_select: Selected CPUs (either a CPU number or MP_SELECT_...) + * @prev_cpu: Previous value returned by mp_first_cpu()/mp_next_cpu() + * @return next CPU number to run on (e.g. 0) + */ +int mp_next_cpu(int cpu_select, int prev_cpu); +#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; +} + +static inline int mp_park_aps(void) +{ + /* No APs to park */ + + return 0; +} + +static inline int mp_first_cpu(int cpu_select) +{ + /* We cannot run on any APs, nor a selected CPU */ + return cpu_select == MP_SELECT_APS ? -EFBIG : MP_SELECT_BSP; +} + +static inline int mp_next_cpu(int cpu_select, int prev_cpu) +{ + /* + * When MP is not enabled, there is only one CPU and we did it in + * mp_first_cpu() + */ + return -EFBIG; +} + +#endif + +#endif /* _X86_MP_H_ */ |