u-boot/arch/x86/include/asm/mp.h

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/*
* Copyright (c) 2015 Google, Inc
*
* SPDX-License-Identifier: GPL-2.0
*
* Taken from coreboot file of the same name
*/
#ifndef _X86_MP_H_
#define _X86_MP_H_
#include <asm/atomic.h>
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.
*/
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)
/*
* The mp_params structure provides the arguments to the mp subsystem
* for bringing up APs.
*
* At present this is overkill for U-Boot, but it may make it easier to add
* SMM support.
*/
struct mp_params {
int parallel_microcode_load;
const void *microcode_pointer;
/* Flight plan for APs and BSP */
struct mp_flight_record *flight_plan;
int num_records;
};
/*
* 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(struct mp_params *params);
/* Probes the CPU device */
int mp_init_cpu(struct udevice *cpu, void *unused);
/* Set up additional CPUs */
int x86_mp_init(void);
#endif /* _X86_MP_H_ */