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// SPDX-License-Identifier: GPL-2.0
/*
* In-kernel vector facility support functions
*
* Copyright IBM Corp. 2015
* Author(s): Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
*/
#include <linux/kernel.h>
#include <linux/cpu.h>
#include <linux/sched.h>
#include <asm/fpu.h>
void __kernel_fpu_begin(struct kernel_fpu *state, int flags)
{
__vector128 *vxrs = state->vxrs;
int mask;
/*
* Limit the save to the FPU/vector registers already
* in use by the previous context.
*/
flags &= state->hdr.mask;
if (flags & KERNEL_FPC)
fpu_stfpc(&state->hdr.fpc);
if (!cpu_has_vx()) {
if (flags & KERNEL_VXR_LOW)
save_fp_regs_vx(vxrs);
return;
}
mask = flags & KERNEL_VXR;
if (mask == KERNEL_VXR) {
vxrs += fpu_vstm(0, 15, vxrs);
vxrs += fpu_vstm(16, 31, vxrs);
return;
}
if (mask == KERNEL_VXR_MID) {
vxrs += fpu_vstm(8, 23, vxrs);
return;
}
mask = flags & KERNEL_VXR_LOW;
if (mask) {
if (mask == KERNEL_VXR_LOW)
vxrs += fpu_vstm(0, 15, vxrs);
else if (mask == KERNEL_VXR_V0V7)
vxrs += fpu_vstm(0, 7, vxrs);
else
vxrs += fpu_vstm(8, 15, vxrs);
}
mask = flags & KERNEL_VXR_HIGH;
if (mask) {
if (mask == KERNEL_VXR_HIGH)
vxrs += fpu_vstm(16, 31, vxrs);
else if (mask == KERNEL_VXR_V16V23)
vxrs += fpu_vstm(16, 23, vxrs);
else
vxrs += fpu_vstm(24, 31, vxrs);
}
}
EXPORT_SYMBOL(__kernel_fpu_begin);
void __kernel_fpu_end(struct kernel_fpu *state, int flags)
{
__vector128 *vxrs = state->vxrs;
int mask;
/*
* Limit the restore to the FPU/vector registers of the
* previous context that have been overwritten by the
* current context.
*/
flags &= state->hdr.mask;
if (flags & KERNEL_FPC)
fpu_lfpc(&state->hdr.fpc);
if (!cpu_has_vx()) {
if (flags & KERNEL_VXR_LOW)
load_fp_regs_vx(vxrs);
return;
}
mask = flags & KERNEL_VXR;
if (mask == KERNEL_VXR) {
vxrs += fpu_vlm(0, 15, vxrs);
vxrs += fpu_vlm(16, 31, vxrs);
return;
}
if (mask == KERNEL_VXR_MID) {
vxrs += fpu_vlm(8, 23, vxrs);
return;
}
mask = flags & KERNEL_VXR_LOW;
if (mask) {
if (mask == KERNEL_VXR_LOW)
vxrs += fpu_vlm(0, 15, vxrs);
else if (mask == KERNEL_VXR_V0V7)
vxrs += fpu_vlm(0, 7, vxrs);
else
vxrs += fpu_vlm(8, 15, vxrs);
}
mask = flags & KERNEL_VXR_HIGH;
if (mask) {
if (mask == KERNEL_VXR_HIGH)
vxrs += fpu_vlm(16, 31, vxrs);
else if (mask == KERNEL_VXR_V16V23)
vxrs += fpu_vlm(16, 23, vxrs);
else
vxrs += fpu_vlm(24, 31, vxrs);
}
}
EXPORT_SYMBOL(__kernel_fpu_end);
void __load_user_fpu_regs(void)
{
struct fpu *state = ¤t->thread.ufpu;
fpu_lfpc_safe(&state->fpc);
if (likely(cpu_has_vx()))
load_vx_regs(state->vxrs);
else
load_fp_regs_vx(state->vxrs);
clear_thread_flag(TIF_FPU);
}
void load_user_fpu_regs(void)
{
raw_local_irq_disable();
__load_user_fpu_regs();
raw_local_irq_enable();
}
EXPORT_SYMBOL(load_user_fpu_regs);
void save_user_fpu_regs(void)
{
unsigned long flags;
struct fpu *state;
local_irq_save(flags);
if (test_thread_flag(TIF_FPU))
goto out;
state = ¤t->thread.ufpu;
fpu_stfpc(&state->fpc);
if (likely(cpu_has_vx()))
save_vx_regs(state->vxrs);
else
save_fp_regs_vx(state->vxrs);
set_thread_flag(TIF_FPU);
out:
local_irq_restore(flags);
}
EXPORT_SYMBOL(save_user_fpu_regs);
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