linux/arch/x86/kernel/fpu/init.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * x86 FPU boot time init code:
 */
#include <asm/fpu/api.h>
#include <asm/tlbflush.h>
#include <asm/setup.h>

#include <linux/sched.h>
#include <linux/sched/task.h>
#include <linux/init.h>

#include "internal.h"
#include "legacy.h"
#include "xstate.h"

/*
 * Initialize the registers found in all CPUs, CR0 and CR4:
 */
static void fpu__init_cpu_generic(void)
{ … }

/*
 * Enable all supported FPU features. Called when a CPU is brought online:
 */
void fpu__init_cpu(void)
{ … }

static bool __init fpu__probe_without_cpuid(void)
{ … }

static void __init fpu__init_system_early_generic(void)
{ … }

/*
 * Boot time FPU feature detection code:
 */
unsigned int mxcsr_feature_mask __ro_after_init = …;
EXPORT_SYMBOL_GPL(…);

static void __init fpu__init_system_mxcsr(void)
{ … }

/*
 * Once per bootup FPU initialization sequences that will run on most x86 CPUs:
 */
static void __init fpu__init_system_generic(void)
{ … }

/*
 * Enforce that 'MEMBER' is the last field of 'TYPE'.
 *
 * Align the computed size with alignment of the TYPE,
 * because that's how C aligns structs.
 */
#define CHECK_MEMBER_AT_END_OF(TYPE, MEMBER) …

/*
 * We append the 'struct fpu' to the task_struct:
 */
static void __init fpu__init_task_struct_size(void)
{ … }

/*
 * Set up the user and kernel xstate sizes based on the legacy FPU context size.
 *
 * We set this up first, and later it will be overwritten by
 * fpu__init_system_xstate() if the CPU knows about xstates.
 */
static void __init fpu__init_system_xstate_size_legacy(void)
{ … }

/*
 * Called on the boot CPU once per system bootup, to set up the initial
 * FPU state that is later cloned into all processes:
 */
void __init fpu__init_system(void)
{ … }