Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 330 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/vector.S b/arch/powerpc/kernel/vector.S
new file mode 100644
index 000000000..21165da00
--- /dev/null
+++ b/arch/powerpc/kernel/vector.S
@@ -0,0 +1,330 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <asm/processor.h>
+#include <asm/ppc_asm.h>
+#include <asm/reg.h>
+#include <asm/asm-offsets.h>
+#include <asm/cputable.h>
+#include <asm/thread_info.h>
+#include <asm/page.h>
+#include <asm/ptrace.h>
+#include <asm/export.h>
+#include <asm/asm-compat.h>
+
+/*
+ * Load state from memory into VMX registers including VSCR.
+ * Assumes the caller has enabled VMX in the MSR.
+ */
+_GLOBAL(load_vr_state)
+	li	r4,VRSTATE_VSCR
+	lvx	v0,r4,r3
+	mtvscr	v0
+	REST_32VRS(0,r4,r3)
+	blr
+EXPORT_SYMBOL(load_vr_state)
+
+/*
+ * Store VMX state into memory, including VSCR.
+ * Assumes the caller has enabled VMX in the MSR.
+ */
+_GLOBAL(store_vr_state)
+	SAVE_32VRS(0, r4, r3)
+	mfvscr	v0
+	li	r4, VRSTATE_VSCR
+	stvx	v0, r4, r3
+	blr
+EXPORT_SYMBOL(store_vr_state)
+
+/*
+ * Disable VMX for the task which had it previously,
+ * and save its vector registers in its thread_struct.
+ * Enables the VMX for use in the kernel on return.
+ * On SMP we know the VMX is free, since we give it up every
+ * switch (ie, no lazy save of the vector registers).
+ *
+ * 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_altivec)
+	mfmsr	r5			/* grab the current MSR */
+	oris	r5,r5,MSR_VEC@h
+	MTMSRD(r5)			/* enable use of AltiVec now */
+	isync
+
+	/*
+	 * While userspace in general ignores VRSAVE, glibc uses it as a boolean
+	 * to optimise userspace context save/restore. Whenever we take an
+	 * altivec unavailable exception we must set VRSAVE to something non
+	 * zero. Set it to all 1s. See also the programming note in the ISA.
+	 */
+	mfspr	r4,SPRN_VRSAVE
+	cmpwi	0,r4,0
+	bne+	1f
+	li	r4,-1
+	mtspr	SPRN_VRSAVE,r4
+1:
+	/* enable use of VMX after return */
+#ifdef CONFIG_PPC32
+	mfspr	r5,SPRN_SPRG_THREAD		/* current task's THREAD (phys) */
+	oris	r9,r9,MSR_VEC@h
+#else
+	ld	r4,PACACURRENT(r13)
+	addi	r5,r4,THREAD		/* Get THREAD */
+	oris	r12,r12,MSR_VEC@h
+	std	r12,_MSR(r1)
+#endif
+	/* Don't care if r4 overflows, this is desired behaviour */
+	lbz	r4,THREAD_LOAD_VEC(r5)
+	addi	r4,r4,1
+	stb	r4,THREAD_LOAD_VEC(r5)
+	addi	r6,r5,THREAD_VRSTATE
+	li	r4,1
+	li	r10,VRSTATE_VSCR
+	stw	r4,THREAD_USED_VR(r5)
+	lvx	v0,r10,r6
+	mtvscr	v0
+	REST_32VRS(0,r4,r6)
+	/* restore registers and return */
+	blr
+
+/*
+ * save_altivec(tsk)
+ * Save the vector registers to its thread_struct
+ */
+_GLOBAL(save_altivec)
+	addi	r3,r3,THREAD		/* want THREAD of task */
+	PPC_LL	r7,THREAD_VRSAVEAREA(r3)
+	PPC_LL	r5,PT_REGS(r3)
+	PPC_LCMPI	0,r7,0
+	bne	2f
+	addi	r7,r3,THREAD_VRSTATE
+2:	SAVE_32VRS(0,r4,r7)
+	mfvscr	v0
+	li	r4,VRSTATE_VSCR
+	stvx	v0,r4,r7
+	blr
+
+#ifdef CONFIG_VSX
+
+#ifdef CONFIG_PPC32
+#error This asm code isn't ready for 32-bit kernels
+#endif
+
+/*
+ * load_up_vsx(unused, unused, tsk)
+ * Disable VSX for the task which had it previously,
+ * and save its vector registers in its thread_struct.
+ * Reuse the fp and vsx saves, but first check to see if they have
+ * been saved already.
+ */
+_GLOBAL(load_up_vsx)
+/* Load FP and VSX registers if they haven't been done yet */
+	andi.	r5,r12,MSR_FP
+	beql+	load_up_fpu		/* skip if already loaded */
+	andis.	r5,r12,MSR_VEC@h
+	beql+	load_up_altivec		/* skip if already loaded */
+
+	ld	r4,PACACURRENT(r13)
+	addi	r4,r4,THREAD		/* Get THREAD */
+	li	r6,1
+	stw	r6,THREAD_USED_VSR(r4) /* ... also set thread used vsr */
+	/* enable use of VSX after return */
+	oris	r12,r12,MSR_VSX@h
+	std	r12,_MSR(r1)
+	b	fast_exception_return
+
+#endif /* CONFIG_VSX */
+
+
+/*
+ * The routines below are in assembler so we can closely control the
+ * usage of floating-point registers.  These routines must be called
+ * with preempt disabled.
+ */
+#ifdef CONFIG_PPC32
+	.data
+fpzero:
+	.long	0
+fpone:
+	.long	0x3f800000	/* 1.0 in single-precision FP */
+fphalf:
+	.long	0x3f000000	/* 0.5 in single-precision FP */
+
+#define LDCONST(fr, name)	\
+	lis	r11,name@ha;	\
+	lfs	fr,name@l(r11)
+#else
+
+	.section ".toc","aw"
+fpzero:
+	.tc	FD_0_0[TC],0
+fpone:
+	.tc	FD_3ff00000_0[TC],0x3ff0000000000000	/* 1.0 */
+fphalf:
+	.tc	FD_3fe00000_0[TC],0x3fe0000000000000	/* 0.5 */
+
+#define LDCONST(fr, name)	\
+	lfd	fr,name@toc(r2)
+#endif
+
+	.text
+/*
+ * Internal routine to enable floating point and set FPSCR to 0.
+ * Don't call it from C; it doesn't use the normal calling convention.
+ */
+fpenable:
+#ifdef CONFIG_PPC32
+	stwu	r1,-64(r1)
+#else
+	stdu	r1,-64(r1)
+#endif
+	mfmsr	r10
+	ori	r11,r10,MSR_FP
+	mtmsr	r11
+	isync
+	stfd	fr0,24(r1)
+	stfd	fr1,16(r1)
+	stfd	fr31,8(r1)
+	LDCONST(fr1, fpzero)
+	mffs	fr31
+	MTFSF_L(fr1)
+	blr
+
+fpdisable:
+	mtlr	r12
+	MTFSF_L(fr31)
+	lfd	fr31,8(r1)
+	lfd	fr1,16(r1)
+	lfd	fr0,24(r1)
+	mtmsr	r10
+	isync
+	addi	r1,r1,64
+	blr
+
+/*
+ * Vector add, floating point.
+ */
+_GLOBAL(vaddfp)
+	mflr	r12
+	bl	fpenable
+	li	r0,4
+	mtctr	r0
+	li	r6,0
+1:	lfsx	fr0,r4,r6
+	lfsx	fr1,r5,r6
+	fadds	fr0,fr0,fr1
+	stfsx	fr0,r3,r6
+	addi	r6,r6,4
+	bdnz	1b
+	b	fpdisable
+
+/*
+ * Vector subtract, floating point.
+ */
+_GLOBAL(vsubfp)
+	mflr	r12
+	bl	fpenable
+	li	r0,4
+	mtctr	r0
+	li	r6,0
+1:	lfsx	fr0,r4,r6
+	lfsx	fr1,r5,r6
+	fsubs	fr0,fr0,fr1
+	stfsx	fr0,r3,r6
+	addi	r6,r6,4
+	bdnz	1b
+	b	fpdisable
+
+/*
+ * Vector multiply and add, floating point.
+ */
+_GLOBAL(vmaddfp)
+	mflr	r12
+	bl	fpenable
+	stfd	fr2,32(r1)
+	li	r0,4
+	mtctr	r0
+	li	r7,0
+1:	lfsx	fr0,r4,r7
+	lfsx	fr1,r5,r7
+	lfsx	fr2,r6,r7
+	fmadds	fr0,fr0,fr2,fr1
+	stfsx	fr0,r3,r7
+	addi	r7,r7,4
+	bdnz	1b
+	lfd	fr2,32(r1)
+	b	fpdisable
+
+/*
+ * Vector negative multiply and subtract, floating point.
+ */
+_GLOBAL(vnmsubfp)
+	mflr	r12
+	bl	fpenable
+	stfd	fr2,32(r1)
+	li	r0,4
+	mtctr	r0
+	li	r7,0
+1:	lfsx	fr0,r4,r7
+	lfsx	fr1,r5,r7
+	lfsx	fr2,r6,r7
+	fnmsubs	fr0,fr0,fr2,fr1
+	stfsx	fr0,r3,r7
+	addi	r7,r7,4
+	bdnz	1b
+	lfd	fr2,32(r1)
+	b	fpdisable
+
+/*
+ * Vector reciprocal estimate.  We just compute 1.0/x.
+ * r3 -> destination, r4 -> source.
+ */
+_GLOBAL(vrefp)
+	mflr	r12
+	bl	fpenable
+	li	r0,4
+	LDCONST(fr1, fpone)
+	mtctr	r0
+	li	r6,0
+1:	lfsx	fr0,r4,r6
+	fdivs	fr0,fr1,fr0
+	stfsx	fr0,r3,r6
+	addi	r6,r6,4
+	bdnz	1b
+	b	fpdisable
+
+/*
+ * Vector reciprocal square-root estimate, floating point.
+ * We use the frsqrte instruction for the initial estimate followed
+ * by 2 iterations of Newton-Raphson to get sufficient accuracy.
+ * r3 -> destination, r4 -> source.
+ */
+_GLOBAL(vrsqrtefp)
+	mflr	r12
+	bl	fpenable
+	stfd	fr2,32(r1)
+	stfd	fr3,40(r1)
+	stfd	fr4,48(r1)
+	stfd	fr5,56(r1)
+	li	r0,4
+	LDCONST(fr4, fpone)
+	LDCONST(fr5, fphalf)
+	mtctr	r0
+	li	r6,0
+1:	lfsx	fr0,r4,r6
+	frsqrte	fr1,fr0		/* r = frsqrte(s) */
+	fmuls	fr3,fr1,fr0	/* r * s */
+	fmuls	fr2,fr1,fr5	/* r * 0.5 */
+	fnmsubs	fr3,fr1,fr3,fr4	/* 1 - s * r * r */
+	fmadds	fr1,fr2,fr3,fr1	/* r = r + 0.5 * r * (1 - s * r * r) */
+	fmuls	fr3,fr1,fr0	/* r * s */
+	fmuls	fr2,fr1,fr5	/* r * 0.5 */
+	fnmsubs	fr3,fr1,fr3,fr4	/* 1 - s * r * r */
+	fmadds	fr1,fr2,fr3,fr1	/* r = r + 0.5 * r * (1 - s * r * r) */
+	stfsx	fr1,r3,r6
+	addi	r6,r6,4
+	bdnz	1b
+	lfd	fr5,56(r1)
+	lfd	fr4,48(r1)
+	lfd	fr3,40(r1)
+	lfd	fr2,32(r1)
+	b	fpdisable