/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* FPU support code, moved here from head.S so that it can be used
* by chips which use other head-whatever.S files.
*
* Copyright (C) 1995-1996 Gary Thomas ([email protected])
* Copyright (C) 1996 Cort Dougan <[email protected]>
* Copyright (C) 1996 Paul Mackerras.
* Copyright (C) 1997 Dan Malek ([email protected]).
*/
#include <linux/export.h>
#include <asm/reg.h>
#include <asm/page.h>
#include <asm/mmu.h>
#include <asm/cputable.h>
#include <asm/cache.h>
#include <asm/thread_info.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/ptrace.h>
#include <asm/asm-compat.h>
#include <asm/feature-fixups.h>
#ifdef CONFIG_VSX
#define __REST_1FPVSR(n,c,base) \
BEGIN_FTR_SECTION \
b 2f; \
END_FTR_SECTION_IFSET(CPU_FTR_VSX); \
REST_FPR(n,base); \
b 3f; \
2: REST_VSR(n,c,base); \
3:
#define __REST_32FPVSRS(n,c,base) \
BEGIN_FTR_SECTION \
b 2f; \
END_FTR_SECTION_IFSET(CPU_FTR_VSX); \
REST_32FPRS(n,base); \
b 3f; \
2: REST_32VSRS(n,c,base); \
3:
#define __SAVE_32FPVSRS(n,c,base) \
BEGIN_FTR_SECTION \
b 2f; \
END_FTR_SECTION_IFSET(CPU_FTR_VSX); \
SAVE_32FPRS(n,base); \
b 3f; \
2: SAVE_32VSRS(n,c,base); \
3:
#else
#define __REST_1FPVSR(n,b,base) REST_FPR(n, base)
#define __REST_32FPVSRS(n,b,base) REST_32FPRS(n, base)
#define __SAVE_32FPVSRS(n,b,base) SAVE_32FPRS(n, base)
#endif
#define REST_1FPVSR(n,c,base) __REST_1FPVSR(n,__REG_##c,__REG_##base)
#define REST_32FPVSRS(n,c,base) __REST_32FPVSRS(n,__REG_##c,__REG_##base)
#define SAVE_32FPVSRS(n,c,base) __SAVE_32FPVSRS(n,__REG_##c,__REG_##base)
/*
* Load state from memory into FP registers including FPSCR.
* Assumes the caller has enabled FP in the MSR.
*/
_GLOBAL(load_fp_state)
lfd fr0,FPSTATE_FPSCR(r3)
MTFSF_L(fr0)
REST_32FPVSRS(0, R4, R3)
blr
EXPORT_SYMBOL(load_fp_state)
_ASM_NOKPROBE_SYMBOL(load_fp_state); /* used by restore_math */
/*
* Store FP state into memory, including FPSCR
* Assumes the caller has enabled FP in the MSR.
*/
_GLOBAL(store_fp_state)
SAVE_32FPVSRS(0, R4, R3)
mffs fr0
stfd fr0,FPSTATE_FPSCR(r3)
REST_1FPVSR(0, R4, R3)
blr
EXPORT_SYMBOL(store_fp_state)
/*
* This task wants to use the FPU now.
* On UP, disable FP for the task which had the FPU previously,
* and save its floating-point registers in its thread_struct.
* Load up this task's FP registers from its thread_struct,
* enable the FPU for the current task and return to the task.
* Note that on 32-bit this can only use registers that will be
* restored by fast_exception_return, i.e. r3 - r6, r10 and r11.
*/
_GLOBAL(load_up_fpu)
mfmsr r5
#ifdef CONFIG_PPC_BOOK3S_64
/* interrupt doesn't set MSR[RI] and HPT can fault on current access */
ori r5,r5,MSR_FP|MSR_RI
#else
ori r5,r5,MSR_FP
#endif
#ifdef CONFIG_VSX
BEGIN_FTR_SECTION
oris r5,r5,MSR_VSX@h
END_FTR_SECTION_IFSET(CPU_FTR_VSX)
#endif
MTMSRD(r5) /* enable use of fpu now */
isync
/* enable use of FP after return */
#ifdef CONFIG_PPC32
addi r5,r2,THREAD
lwz r4,THREAD_FPEXC_MODE(r5)
ori r9,r9,MSR_FP /* enable FP for current */
or r9,r9,r4
#else
ld r4,PACACURRENT(r13)
addi r5,r4,THREAD /* Get THREAD */
lwz r4,THREAD_FPEXC_MODE(r5)
ori r12,r12,MSR_FP
or r12,r12,r4
std r12,_MSR(r1)
#ifdef CONFIG_PPC_BOOK3S_64
li r4,0
stb r4,PACASRR_VALID(r13)
#endif
#endif
li r4,1
stb r4,THREAD_LOAD_FP(r5)
addi r10,r5,THREAD_FPSTATE
lfd fr0,FPSTATE_FPSCR(r10)
MTFSF_L(fr0)
REST_32FPVSRS(0, R4, R10)
/* restore registers and return */
/* we haven't used ctr or xer or lr */
blr
_ASM_NOKPROBE_SYMBOL(load_up_fpu)
/*
* save_fpu(tsk)
* Save the floating-point registers in its thread_struct.
* Enables the FPU for use in the kernel on return.
*/
_GLOBAL(save_fpu)
addi r3,r3,THREAD /* want THREAD of task */
PPC_LL r6,THREAD_FPSAVEAREA(r3)
PPC_LL r5,PT_REGS(r3)
PPC_LCMPI 0,r6,0
bne 2f
addi r6,r3,THREAD_FPSTATE
2: SAVE_32FPVSRS(0, R4, R6)
mffs fr0
stfd fr0,FPSTATE_FPSCR(r6)
REST_1FPVSR(0, R4, R6)
blr
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