331 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			331 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| /* SPDX-License-Identifier: GPL-2.0 */
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| #include <asm/processor.h>
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| #include <asm/ppc_asm.h>
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| #include <asm/reg.h>
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| #include <asm/asm-offsets.h>
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| #include <asm/cputable.h>
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| #include <asm/thread_info.h>
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| #include <asm/page.h>
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| #include <asm/ptrace.h>
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| #include <asm/export.h>
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| #include <asm/asm-compat.h>
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| 
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| /*
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|  * Load state from memory into VMX registers including VSCR.
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|  * Assumes the caller has enabled VMX in the MSR.
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|  */
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| _GLOBAL(load_vr_state)
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| 	li	r4,VRSTATE_VSCR
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| 	lvx	v0,r4,r3
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| 	mtvscr	v0
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| 	REST_32VRS(0,r4,r3)
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| 	blr
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| EXPORT_SYMBOL(load_vr_state)
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| 
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| /*
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|  * Store VMX state into memory, including VSCR.
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|  * Assumes the caller has enabled VMX in the MSR.
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|  */
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| _GLOBAL(store_vr_state)
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| 	SAVE_32VRS(0, r4, r3)
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| 	mfvscr	v0
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| 	li	r4, VRSTATE_VSCR
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| 	stvx	v0, r4, r3
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| 	blr
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| EXPORT_SYMBOL(store_vr_state)
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| 
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| /*
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|  * Disable VMX for the task which had it previously,
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|  * and save its vector registers in its thread_struct.
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|  * Enables the VMX for use in the kernel on return.
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|  * On SMP we know the VMX is free, since we give it up every
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|  * switch (ie, no lazy save of the vector registers).
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|  *
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|  * Note that on 32-bit this can only use registers that will be
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|  * restored by fast_exception_return, i.e. r3 - r6, r10 and r11.
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|  */
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| _GLOBAL(load_up_altivec)
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| 	mfmsr	r5			/* grab the current MSR */
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| 	oris	r5,r5,MSR_VEC@h
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| 	MTMSRD(r5)			/* enable use of AltiVec now */
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| 	isync
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| 
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| 	/*
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| 	 * While userspace in general ignores VRSAVE, glibc uses it as a boolean
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| 	 * to optimise userspace context save/restore. Whenever we take an
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| 	 * altivec unavailable exception we must set VRSAVE to something non
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| 	 * zero. Set it to all 1s. See also the programming note in the ISA.
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| 	 */
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| 	mfspr	r4,SPRN_VRSAVE
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| 	cmpwi	0,r4,0
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| 	bne+	1f
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| 	li	r4,-1
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| 	mtspr	SPRN_VRSAVE,r4
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| 1:
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| 	/* enable use of VMX after return */
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| #ifdef CONFIG_PPC32
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| 	mfspr	r5,SPRN_SPRG_THREAD		/* current task's THREAD (phys) */
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| 	oris	r9,r9,MSR_VEC@h
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| #else
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| 	ld	r4,PACACURRENT(r13)
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| 	addi	r5,r4,THREAD		/* Get THREAD */
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| 	oris	r12,r12,MSR_VEC@h
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| 	std	r12,_MSR(r1)
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| #endif
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| 	/* Don't care if r4 overflows, this is desired behaviour */
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| 	lbz	r4,THREAD_LOAD_VEC(r5)
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| 	addi	r4,r4,1
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| 	stb	r4,THREAD_LOAD_VEC(r5)
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| 	addi	r6,r5,THREAD_VRSTATE
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| 	li	r4,1
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| 	li	r10,VRSTATE_VSCR
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| 	stw	r4,THREAD_USED_VR(r5)
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| 	lvx	v0,r10,r6
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| 	mtvscr	v0
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| 	REST_32VRS(0,r4,r6)
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| 	/* restore registers and return */
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| 	blr
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| 
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| /*
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|  * save_altivec(tsk)
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|  * Save the vector registers to its thread_struct
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|  */
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| _GLOBAL(save_altivec)
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| 	addi	r3,r3,THREAD		/* want THREAD of task */
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| 	PPC_LL	r7,THREAD_VRSAVEAREA(r3)
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| 	PPC_LL	r5,PT_REGS(r3)
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| 	PPC_LCMPI	0,r7,0
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| 	bne	2f
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| 	addi	r7,r3,THREAD_VRSTATE
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| 2:	SAVE_32VRS(0,r4,r7)
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| 	mfvscr	v0
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| 	li	r4,VRSTATE_VSCR
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| 	stvx	v0,r4,r7
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| 	blr
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| 
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| #ifdef CONFIG_VSX
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| 
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| #ifdef CONFIG_PPC32
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| #error This asm code isn't ready for 32-bit kernels
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| #endif
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| 
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| /*
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|  * load_up_vsx(unused, unused, tsk)
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|  * Disable VSX for the task which had it previously,
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|  * and save its vector registers in its thread_struct.
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|  * Reuse the fp and vsx saves, but first check to see if they have
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|  * been saved already.
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|  */
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| _GLOBAL(load_up_vsx)
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| /* Load FP and VSX registers if they haven't been done yet */
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| 	andi.	r5,r12,MSR_FP
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| 	beql+	load_up_fpu		/* skip if already loaded */
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| 	andis.	r5,r12,MSR_VEC@h
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| 	beql+	load_up_altivec		/* skip if already loaded */
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| 
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| 	ld	r4,PACACURRENT(r13)
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| 	addi	r4,r4,THREAD		/* Get THREAD */
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| 	li	r6,1
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| 	stw	r6,THREAD_USED_VSR(r4) /* ... also set thread used vsr */
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| 	/* enable use of VSX after return */
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| 	oris	r12,r12,MSR_VSX@h
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| 	std	r12,_MSR(r1)
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| 	b	fast_exception_return
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| 
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| #endif /* CONFIG_VSX */
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| 
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| 
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| /*
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|  * The routines below are in assembler so we can closely control the
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|  * usage of floating-point registers.  These routines must be called
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|  * with preempt disabled.
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|  */
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| #ifdef CONFIG_PPC32
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| 	.data
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| fpzero:
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| 	.long	0
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| fpone:
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| 	.long	0x3f800000	/* 1.0 in single-precision FP */
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| fphalf:
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| 	.long	0x3f000000	/* 0.5 in single-precision FP */
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| 
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| #define LDCONST(fr, name)	\
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| 	lis	r11,name@ha;	\
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| 	lfs	fr,name@l(r11)
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| #else
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| 
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| 	.section ".toc","aw"
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| fpzero:
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| 	.tc	FD_0_0[TC],0
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| fpone:
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| 	.tc	FD_3ff00000_0[TC],0x3ff0000000000000	/* 1.0 */
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| fphalf:
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| 	.tc	FD_3fe00000_0[TC],0x3fe0000000000000	/* 0.5 */
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| 
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| #define LDCONST(fr, name)	\
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| 	lfd	fr,name@toc(r2)
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| #endif
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| 
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| 	.text
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| /*
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|  * Internal routine to enable floating point and set FPSCR to 0.
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|  * Don't call it from C; it doesn't use the normal calling convention.
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|  */
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| fpenable:
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| #ifdef CONFIG_PPC32
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| 	stwu	r1,-64(r1)
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| #else
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| 	stdu	r1,-64(r1)
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| #endif
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| 	mfmsr	r10
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| 	ori	r11,r10,MSR_FP
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| 	mtmsr	r11
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| 	isync
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| 	stfd	fr0,24(r1)
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| 	stfd	fr1,16(r1)
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| 	stfd	fr31,8(r1)
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| 	LDCONST(fr1, fpzero)
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| 	mffs	fr31
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| 	MTFSF_L(fr1)
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| 	blr
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| 
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| fpdisable:
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| 	mtlr	r12
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| 	MTFSF_L(fr31)
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| 	lfd	fr31,8(r1)
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| 	lfd	fr1,16(r1)
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| 	lfd	fr0,24(r1)
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| 	mtmsr	r10
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| 	isync
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| 	addi	r1,r1,64
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| 	blr
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| 
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| /*
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|  * Vector add, floating point.
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|  */
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| _GLOBAL(vaddfp)
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| 	mflr	r12
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| 	bl	fpenable
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| 	li	r0,4
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| 	mtctr	r0
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| 	li	r6,0
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| 1:	lfsx	fr0,r4,r6
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| 	lfsx	fr1,r5,r6
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| 	fadds	fr0,fr0,fr1
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| 	stfsx	fr0,r3,r6
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| 	addi	r6,r6,4
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| 	bdnz	1b
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| 	b	fpdisable
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| 
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| /*
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|  * Vector subtract, floating point.
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|  */
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| _GLOBAL(vsubfp)
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| 	mflr	r12
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| 	bl	fpenable
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| 	li	r0,4
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| 	mtctr	r0
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| 	li	r6,0
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| 1:	lfsx	fr0,r4,r6
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| 	lfsx	fr1,r5,r6
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| 	fsubs	fr0,fr0,fr1
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| 	stfsx	fr0,r3,r6
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| 	addi	r6,r6,4
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| 	bdnz	1b
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| 	b	fpdisable
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| 
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| /*
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|  * Vector multiply and add, floating point.
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|  */
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| _GLOBAL(vmaddfp)
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| 	mflr	r12
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| 	bl	fpenable
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| 	stfd	fr2,32(r1)
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| 	li	r0,4
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| 	mtctr	r0
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| 	li	r7,0
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| 1:	lfsx	fr0,r4,r7
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| 	lfsx	fr1,r5,r7
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| 	lfsx	fr2,r6,r7
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| 	fmadds	fr0,fr0,fr2,fr1
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| 	stfsx	fr0,r3,r7
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| 	addi	r7,r7,4
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| 	bdnz	1b
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| 	lfd	fr2,32(r1)
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| 	b	fpdisable
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| 
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| /*
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|  * Vector negative multiply and subtract, floating point.
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|  */
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| _GLOBAL(vnmsubfp)
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| 	mflr	r12
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| 	bl	fpenable
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| 	stfd	fr2,32(r1)
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| 	li	r0,4
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| 	mtctr	r0
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| 	li	r7,0
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| 1:	lfsx	fr0,r4,r7
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| 	lfsx	fr1,r5,r7
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| 	lfsx	fr2,r6,r7
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| 	fnmsubs	fr0,fr0,fr2,fr1
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| 	stfsx	fr0,r3,r7
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| 	addi	r7,r7,4
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| 	bdnz	1b
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| 	lfd	fr2,32(r1)
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| 	b	fpdisable
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| 
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| /*
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|  * Vector reciprocal estimate.  We just compute 1.0/x.
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|  * r3 -> destination, r4 -> source.
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|  */
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| _GLOBAL(vrefp)
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| 	mflr	r12
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| 	bl	fpenable
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| 	li	r0,4
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| 	LDCONST(fr1, fpone)
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| 	mtctr	r0
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| 	li	r6,0
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| 1:	lfsx	fr0,r4,r6
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| 	fdivs	fr0,fr1,fr0
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| 	stfsx	fr0,r3,r6
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| 	addi	r6,r6,4
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| 	bdnz	1b
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| 	b	fpdisable
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| 
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| /*
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|  * Vector reciprocal square-root estimate, floating point.
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|  * We use the frsqrte instruction for the initial estimate followed
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|  * by 2 iterations of Newton-Raphson to get sufficient accuracy.
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|  * r3 -> destination, r4 -> source.
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|  */
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| _GLOBAL(vrsqrtefp)
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| 	mflr	r12
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| 	bl	fpenable
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| 	stfd	fr2,32(r1)
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| 	stfd	fr3,40(r1)
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| 	stfd	fr4,48(r1)
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| 	stfd	fr5,56(r1)
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| 	li	r0,4
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| 	LDCONST(fr4, fpone)
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| 	LDCONST(fr5, fphalf)
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| 	mtctr	r0
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| 	li	r6,0
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| 1:	lfsx	fr0,r4,r6
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| 	frsqrte	fr1,fr0		/* r = frsqrte(s) */
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| 	fmuls	fr3,fr1,fr0	/* r * s */
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| 	fmuls	fr2,fr1,fr5	/* r * 0.5 */
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| 	fnmsubs	fr3,fr1,fr3,fr4	/* 1 - s * r * r */
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| 	fmadds	fr1,fr2,fr3,fr1	/* r = r + 0.5 * r * (1 - s * r * r) */
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| 	fmuls	fr3,fr1,fr0	/* r * s */
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| 	fmuls	fr2,fr1,fr5	/* r * 0.5 */
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| 	fnmsubs	fr3,fr1,fr3,fr4	/* 1 - s * r * r */
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| 	fmadds	fr1,fr2,fr3,fr1	/* r = r + 0.5 * r * (1 - s * r * r) */
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| 	stfsx	fr1,r3,r6
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| 	addi	r6,r6,4
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| 	bdnz	1b
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| 	lfd	fr5,56(r1)
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| 	lfd	fr4,48(r1)
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| 	lfd	fr3,40(r1)
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| 	lfd	fr2,32(r1)
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| 	b	fpdisable
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