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https://github.com/AsahiLinux/u-boot
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45b5a37836
Most modern x86 CPUs include more than one CPU core. The OS normally requires that these 'Application Processors' (APs) be brought up by the boot loader. Add the required support to U-Boot to init additional APs. Signed-off-by: Simon Glass <sjg@chromium.org> Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
94 lines
3 KiB
C
94 lines
3 KiB
C
/*
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* Copyright (c) 2015 Google, Inc
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*
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* SPDX-License-Identifier: GPL-2.0
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*
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* Taken from coreboot file of the same name
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*/
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#ifndef _X86_MP_H_
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#define _X86_MP_H_
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#include <asm/atomic.h>
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typedef int (*mp_callback_t)(struct udevice *cpu, void *arg);
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/*
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* A mp_flight_record details a sequence of calls for the APs to perform
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* along with the BSP to coordinate sequencing. Each flight record either
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* provides a barrier for each AP before calling the callback or the APs
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* are allowed to perform the callback without waiting. Regardless, each
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* record has the cpus_entered field incremented for each record. When
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* the BSP observes that the cpus_entered matches the number of APs
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* the bsp_call is called with bsp_arg and upon returning releases the
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* barrier allowing the APs to make further progress.
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*
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* Note that ap_call() and bsp_call() can be NULL. In the NULL case the
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* callback will just not be called.
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*/
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struct mp_flight_record {
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atomic_t barrier;
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atomic_t cpus_entered;
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mp_callback_t ap_call;
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void *ap_arg;
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mp_callback_t bsp_call;
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void *bsp_arg;
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} __attribute__((aligned(ARCH_DMA_MINALIGN)));
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#define MP_FLIGHT_RECORD(barrier_, ap_func_, ap_arg_, bsp_func_, bsp_arg_) \
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{ \
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.barrier = ATOMIC_INIT(barrier_), \
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.cpus_entered = ATOMIC_INIT(0), \
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.ap_call = ap_func_, \
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.ap_arg = ap_arg_, \
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.bsp_call = bsp_func_, \
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.bsp_arg = bsp_arg_, \
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}
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#define MP_FR_BLOCK_APS(ap_func, ap_arg, bsp_func, bsp_arg) \
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MP_FLIGHT_RECORD(0, ap_func, ap_arg, bsp_func, bsp_arg)
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#define MP_FR_NOBLOCK_APS(ap_func, ap_arg, bsp_func, bsp_arg) \
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MP_FLIGHT_RECORD(1, ap_func, ap_arg, bsp_func, bsp_arg)
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/*
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* The mp_params structure provides the arguments to the mp subsystem
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* for bringing up APs.
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*
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* At present this is overkill for U-Boot, but it may make it easier to add
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* SMM support.
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*/
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struct mp_params {
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int num_cpus; /* Total cpus include BSP */
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int parallel_microcode_load;
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const void *microcode_pointer;
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/* Flight plan for APs and BSP */
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struct mp_flight_record *flight_plan;
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int num_records;
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};
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/*
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* mp_init() will set up the SIPI vector and bring up the APs according to
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* mp_params. Each flight record will be executed according to the plan. Note
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* that the MP infrastructure uses SMM default area without saving it. It's
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* up to the chipset or mainboard to either e820 reserve this area or save this
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* region prior to calling mp_init() and restoring it after mp_init returns.
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*
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* At the time mp_init() is called the MTRR MSRs are mirrored into APs then
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* caching is enabled before running the flight plan.
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*
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* The MP init has the following properties:
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* 1. APs are brought up in parallel.
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* 2. The ordering of cpu number and APIC ids is not deterministic.
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* Therefore, one cannot rely on this property or the order of devices in
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* the device tree unless the chipset or mainboard know the APIC ids
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* a priori.
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*
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* mp_init() returns < 0 on error, 0 on success.
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*/
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int mp_init(struct mp_params *params);
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/* Probes the CPU device */
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int mp_init_cpu(struct udevice *cpu, void *unused);
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#endif /* _X86_MP_H_ */
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