Adding upstream version 5.10.209.upstream/5.10.209upstream

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

1 files changed, 425 insertions, 0 deletions

diff --git a/arch/sh/kernel/cpu/sh4/fpu.c b/arch/sh/kernel/cpu/sh4/fpu.c
new file mode 100644
index 000000000..03ffd8cdf
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4/fpu.c
@@ -0,0 +1,425 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Save/restore floating point context for signal handlers.
+ *
+ * Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
+ * Copyright (C) 2006  ST Microelectronics Ltd. (denorm support)
+ *
+ * FIXME! These routines have not been tested for big endian case.
+ */
+#include <linux/sched/signal.h>
+#include <linux/io.h>
+#include <cpu/fpu.h>
+#include <asm/processor.h>
+#include <asm/fpu.h>
+#include <asm/traps.h>
+
+/* The PR (precision) bit in the FP Status Register must be clear when
+ * an frchg instruction is executed, otherwise the instruction is undefined.
+ * Executing frchg with PR set causes a trap on some SH4 implementations.
+ */
+
+#define FPSCR_RCHG 0x00000000
+extern unsigned long long float64_div(unsigned long long a,
+				      unsigned long long b);
+extern unsigned long int float32_div(unsigned long int a, unsigned long int b);
+extern unsigned long long float64_mul(unsigned long long a,
+				      unsigned long long b);
+extern unsigned long int float32_mul(unsigned long int a, unsigned long int b);
+extern unsigned long long float64_add(unsigned long long a,
+				      unsigned long long b);
+extern unsigned long int float32_add(unsigned long int a, unsigned long int b);
+extern unsigned long long float64_sub(unsigned long long a,
+				      unsigned long long b);
+extern unsigned long int float32_sub(unsigned long int a, unsigned long int b);
+extern unsigned long int float64_to_float32(unsigned long long a);
+static unsigned int fpu_exception_flags;
+
+/*
+ * Save FPU registers onto task structure.
+ */
+void save_fpu(struct task_struct *tsk)
+{
+	unsigned long dummy;
+
+	enable_fpu();
+	asm volatile ("sts.l	fpul, @-%0\n\t"
+		      "sts.l	fpscr, @-%0\n\t"
+		      "lds	%2, fpscr\n\t"
+		      "frchg\n\t"
+		      "fmov.s	fr15, @-%0\n\t"
+		      "fmov.s	fr14, @-%0\n\t"
+		      "fmov.s	fr13, @-%0\n\t"
+		      "fmov.s	fr12, @-%0\n\t"
+		      "fmov.s	fr11, @-%0\n\t"
+		      "fmov.s	fr10, @-%0\n\t"
+		      "fmov.s	fr9, @-%0\n\t"
+		      "fmov.s	fr8, @-%0\n\t"
+		      "fmov.s	fr7, @-%0\n\t"
+		      "fmov.s	fr6, @-%0\n\t"
+		      "fmov.s	fr5, @-%0\n\t"
+		      "fmov.s	fr4, @-%0\n\t"
+		      "fmov.s	fr3, @-%0\n\t"
+		      "fmov.s	fr2, @-%0\n\t"
+		      "fmov.s	fr1, @-%0\n\t"
+		      "fmov.s	fr0, @-%0\n\t"
+		      "frchg\n\t"
+		      "fmov.s	fr15, @-%0\n\t"
+		      "fmov.s	fr14, @-%0\n\t"
+		      "fmov.s	fr13, @-%0\n\t"
+		      "fmov.s	fr12, @-%0\n\t"
+		      "fmov.s	fr11, @-%0\n\t"
+		      "fmov.s	fr10, @-%0\n\t"
+		      "fmov.s	fr9, @-%0\n\t"
+		      "fmov.s	fr8, @-%0\n\t"
+		      "fmov.s	fr7, @-%0\n\t"
+		      "fmov.s	fr6, @-%0\n\t"
+		      "fmov.s	fr5, @-%0\n\t"
+		      "fmov.s	fr4, @-%0\n\t"
+		      "fmov.s	fr3, @-%0\n\t"
+		      "fmov.s	fr2, @-%0\n\t"
+		      "fmov.s	fr1, @-%0\n\t"
+		      "fmov.s	fr0, @-%0\n\t"
+		      "lds	%3, fpscr\n\t":"=r" (dummy)
+		      :"0"((char *)(&tsk->thread.xstate->hardfpu.status)),
+		      "r"(FPSCR_RCHG), "r"(FPSCR_INIT)
+		      :"memory");
+
+	disable_fpu();
+}
+
+void restore_fpu(struct task_struct *tsk)
+{
+	unsigned long dummy;
+
+	enable_fpu();
+	asm volatile ("lds	%2, fpscr\n\t"
+		      "fmov.s	@%0+, fr0\n\t"
+		      "fmov.s	@%0+, fr1\n\t"
+		      "fmov.s	@%0+, fr2\n\t"
+		      "fmov.s	@%0+, fr3\n\t"
+		      "fmov.s	@%0+, fr4\n\t"
+		      "fmov.s	@%0+, fr5\n\t"
+		      "fmov.s	@%0+, fr6\n\t"
+		      "fmov.s	@%0+, fr7\n\t"
+		      "fmov.s	@%0+, fr8\n\t"
+		      "fmov.s	@%0+, fr9\n\t"
+		      "fmov.s	@%0+, fr10\n\t"
+		      "fmov.s	@%0+, fr11\n\t"
+		      "fmov.s	@%0+, fr12\n\t"
+		      "fmov.s	@%0+, fr13\n\t"
+		      "fmov.s	@%0+, fr14\n\t"
+		      "fmov.s	@%0+, fr15\n\t"
+		      "frchg\n\t"
+		      "fmov.s	@%0+, fr0\n\t"
+		      "fmov.s	@%0+, fr1\n\t"
+		      "fmov.s	@%0+, fr2\n\t"
+		      "fmov.s	@%0+, fr3\n\t"
+		      "fmov.s	@%0+, fr4\n\t"
+		      "fmov.s	@%0+, fr5\n\t"
+		      "fmov.s	@%0+, fr6\n\t"
+		      "fmov.s	@%0+, fr7\n\t"
+		      "fmov.s	@%0+, fr8\n\t"
+		      "fmov.s	@%0+, fr9\n\t"
+		      "fmov.s	@%0+, fr10\n\t"
+		      "fmov.s	@%0+, fr11\n\t"
+		      "fmov.s	@%0+, fr12\n\t"
+		      "fmov.s	@%0+, fr13\n\t"
+		      "fmov.s	@%0+, fr14\n\t"
+		      "fmov.s	@%0+, fr15\n\t"
+		      "frchg\n\t"
+		      "lds.l	@%0+, fpscr\n\t"
+		      "lds.l	@%0+, fpul\n\t"
+		      :"=r" (dummy)
+		      :"0" (tsk->thread.xstate), "r" (FPSCR_RCHG)
+		      :"memory");
+	disable_fpu();
+}
+
+/**
+ *      denormal_to_double - Given denormalized float number,
+ *                           store double float
+ *
+ *      @fpu: Pointer to sh_fpu_hard structure
+ *      @n: Index to FP register
+ */
+static void denormal_to_double(struct sh_fpu_hard_struct *fpu, int n)
+{
+	unsigned long du, dl;
+	unsigned long x = fpu->fpul;
+	int exp = 1023 - 126;
+
+	if (x != 0 && (x & 0x7f800000) == 0) {
+		du = (x & 0x80000000);
+		while ((x & 0x00800000) == 0) {
+			x <<= 1;
+			exp--;
+		}
+		x &= 0x007fffff;
+		du |= (exp << 20) | (x >> 3);
+		dl = x << 29;
+
+		fpu->fp_regs[n] = du;
+		fpu->fp_regs[n + 1] = dl;
+	}
+}
+
+/**
+ *	ieee_fpe_handler - Handle denormalized number exception
+ *
+ *	@regs: Pointer to register structure
+ *
+ *	Returns 1 when it's handled (should not cause exception).
+ */
+static int ieee_fpe_handler(struct pt_regs *regs)
+{
+	unsigned short insn = *(unsigned short *)regs->pc;
+	unsigned short finsn;
+	unsigned long nextpc;
+	int nib[4] = {
+		(insn >> 12) & 0xf,
+		(insn >> 8) & 0xf,
+		(insn >> 4) & 0xf,
+		insn & 0xf
+	};
+
+	if (nib[0] == 0xb || (nib[0] == 0x4 && nib[2] == 0x0 && nib[3] == 0xb))
+		regs->pr = regs->pc + 4;  /* bsr & jsr */
+
+	if (nib[0] == 0xa || nib[0] == 0xb) {
+		/* bra & bsr */
+		nextpc = regs->pc + 4 + ((short)((insn & 0xfff) << 4) >> 3);
+		finsn = *(unsigned short *)(regs->pc + 2);
+	} else if (nib[0] == 0x8 && nib[1] == 0xd) {
+		/* bt/s */
+		if (regs->sr & 1)
+			nextpc = regs->pc + 4 + ((char)(insn & 0xff) << 1);
+		else
+			nextpc = regs->pc + 4;
+		finsn = *(unsigned short *)(regs->pc + 2);
+	} else if (nib[0] == 0x8 && nib[1] == 0xf) {
+		/* bf/s */
+		if (regs->sr & 1)
+			nextpc = regs->pc + 4;
+		else
+			nextpc = regs->pc + 4 + ((char)(insn & 0xff) << 1);
+		finsn = *(unsigned short *)(regs->pc + 2);
+	} else if (nib[0] == 0x4 && nib[3] == 0xb &&
+		   (nib[2] == 0x0 || nib[2] == 0x2)) {
+		/* jmp & jsr */
+		nextpc = regs->regs[nib[1]];
+		finsn = *(unsigned short *)(regs->pc + 2);
+	} else if (nib[0] == 0x0 && nib[3] == 0x3 &&
+		   (nib[2] == 0x0 || nib[2] == 0x2)) {
+		/* braf & bsrf */
+		nextpc = regs->pc + 4 + regs->regs[nib[1]];
+		finsn = *(unsigned short *)(regs->pc + 2);
+	} else if (insn == 0x000b) {
+		/* rts */
+		nextpc = regs->pr;
+		finsn = *(unsigned short *)(regs->pc + 2);
+	} else {
+		nextpc = regs->pc + instruction_size(insn);
+		finsn = insn;
+	}
+
+	if ((finsn & 0xf1ff) == 0xf0ad) {
+		/* fcnvsd */
+		struct task_struct *tsk = current;
+
+		if ((tsk->thread.xstate->hardfpu.fpscr & FPSCR_CAUSE_ERROR))
+			/* FPU error */
+			denormal_to_double(&tsk->thread.xstate->hardfpu,
+					   (finsn >> 8) & 0xf);
+		else
+			return 0;
+
+		regs->pc = nextpc;
+		return 1;
+	} else if ((finsn & 0xf00f) == 0xf002) {
+		/* fmul */
+		struct task_struct *tsk = current;
+		int fpscr;
+		int n, m, prec;
+		unsigned int hx, hy;
+
+		n = (finsn >> 8) & 0xf;
+		m = (finsn >> 4) & 0xf;
+		hx = tsk->thread.xstate->hardfpu.fp_regs[n];
+		hy = tsk->thread.xstate->hardfpu.fp_regs[m];
+		fpscr = tsk->thread.xstate->hardfpu.fpscr;
+		prec = fpscr & FPSCR_DBL_PRECISION;
+
+		if ((fpscr & FPSCR_CAUSE_ERROR)
+		    && (prec && ((hx & 0x7fffffff) < 0x00100000
+				 || (hy & 0x7fffffff) < 0x00100000))) {
+			long long llx, lly;
+
+			/* FPU error because of denormal (doubles) */
+			llx = ((long long)hx << 32)
+			    | tsk->thread.xstate->hardfpu.fp_regs[n + 1];
+			lly = ((long long)hy << 32)
+			    | tsk->thread.xstate->hardfpu.fp_regs[m + 1];
+			llx = float64_mul(llx, lly);
+			tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32;
+			tsk->thread.xstate->hardfpu.fp_regs[n + 1] = llx & 0xffffffff;
+		} else if ((fpscr & FPSCR_CAUSE_ERROR)
+			   && (!prec && ((hx & 0x7fffffff) < 0x00800000
+					 || (hy & 0x7fffffff) < 0x00800000))) {
+			/* FPU error because of denormal (floats) */
+			hx = float32_mul(hx, hy);
+			tsk->thread.xstate->hardfpu.fp_regs[n] = hx;
+		} else
+			return 0;
+
+		regs->pc = nextpc;
+		return 1;
+	} else if ((finsn & 0xf00e) == 0xf000) {
+		/* fadd, fsub */
+		struct task_struct *tsk = current;
+		int fpscr;
+		int n, m, prec;
+		unsigned int hx, hy;
+
+		n = (finsn >> 8) & 0xf;
+		m = (finsn >> 4) & 0xf;
+		hx = tsk->thread.xstate->hardfpu.fp_regs[n];
+		hy = tsk->thread.xstate->hardfpu.fp_regs[m];
+		fpscr = tsk->thread.xstate->hardfpu.fpscr;
+		prec = fpscr & FPSCR_DBL_PRECISION;
+
+		if ((fpscr & FPSCR_CAUSE_ERROR)
+		    && (prec && ((hx & 0x7fffffff) < 0x00100000
+				 || (hy & 0x7fffffff) < 0x00100000))) {
+			long long llx, lly;
+
+			/* FPU error because of denormal (doubles) */
+			llx = ((long long)hx << 32)
+			    | tsk->thread.xstate->hardfpu.fp_regs[n + 1];
+			lly = ((long long)hy << 32)
+			    | tsk->thread.xstate->hardfpu.fp_regs[m + 1];
+			if ((finsn & 0xf00f) == 0xf000)
+				llx = float64_add(llx, lly);
+			else
+				llx = float64_sub(llx, lly);
+			tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32;
+			tsk->thread.xstate->hardfpu.fp_regs[n + 1] = llx & 0xffffffff;
+		} else if ((fpscr & FPSCR_CAUSE_ERROR)
+			   && (!prec && ((hx & 0x7fffffff) < 0x00800000
+					 || (hy & 0x7fffffff) < 0x00800000))) {
+			/* FPU error because of denormal (floats) */
+			if ((finsn & 0xf00f) == 0xf000)
+				hx = float32_add(hx, hy);
+			else
+				hx = float32_sub(hx, hy);
+			tsk->thread.xstate->hardfpu.fp_regs[n] = hx;
+		} else
+			return 0;
+
+		regs->pc = nextpc;
+		return 1;
+	} else if ((finsn & 0xf003) == 0xf003) {
+		/* fdiv */
+		struct task_struct *tsk = current;
+		int fpscr;
+		int n, m, prec;
+		unsigned int hx, hy;
+
+		n = (finsn >> 8) & 0xf;
+		m = (finsn >> 4) & 0xf;
+		hx = tsk->thread.xstate->hardfpu.fp_regs[n];
+		hy = tsk->thread.xstate->hardfpu.fp_regs[m];
+		fpscr = tsk->thread.xstate->hardfpu.fpscr;
+		prec = fpscr & FPSCR_DBL_PRECISION;
+
+		if ((fpscr & FPSCR_CAUSE_ERROR)
+		    && (prec && ((hx & 0x7fffffff) < 0x00100000
+				 || (hy & 0x7fffffff) < 0x00100000))) {
+			long long llx, lly;
+
+			/* FPU error because of denormal (doubles) */
+			llx = ((long long)hx << 32)
+			    | tsk->thread.xstate->hardfpu.fp_regs[n + 1];
+			lly = ((long long)hy << 32)
+			    | tsk->thread.xstate->hardfpu.fp_regs[m + 1];
+
+			llx = float64_div(llx, lly);
+
+			tsk->thread.xstate->hardfpu.fp_regs[n] = llx >> 32;
+			tsk->thread.xstate->hardfpu.fp_regs[n + 1] = llx & 0xffffffff;
+		} else if ((fpscr & FPSCR_CAUSE_ERROR)
+			   && (!prec && ((hx & 0x7fffffff) < 0x00800000
+					 || (hy & 0x7fffffff) < 0x00800000))) {
+			/* FPU error because of denormal (floats) */
+			hx = float32_div(hx, hy);
+			tsk->thread.xstate->hardfpu.fp_regs[n] = hx;
+		} else
+			return 0;
+
+		regs->pc = nextpc;
+		return 1;
+	} else if ((finsn & 0xf0bd) == 0xf0bd) {
+		/* fcnvds - double to single precision convert */
+		struct task_struct *tsk = current;
+		int m;
+		unsigned int hx;
+
+		m = (finsn >> 8) & 0x7;
+		hx = tsk->thread.xstate->hardfpu.fp_regs[m];
+
+		if ((tsk->thread.xstate->hardfpu.fpscr & FPSCR_CAUSE_ERROR)
+			&& ((hx & 0x7fffffff) < 0x00100000)) {
+			/* subnormal double to float conversion */
+			long long llx;
+
+			llx = ((long long)tsk->thread.xstate->hardfpu.fp_regs[m] << 32)
+			    | tsk->thread.xstate->hardfpu.fp_regs[m + 1];
+
+			tsk->thread.xstate->hardfpu.fpul = float64_to_float32(llx);
+		} else
+			return 0;
+
+		regs->pc = nextpc;
+		return 1;
+	}
+
+	return 0;
+}
+
+void float_raise(unsigned int flags)
+{
+	fpu_exception_flags |= flags;
+}
+
+int float_rounding_mode(void)
+{
+	struct task_struct *tsk = current;
+	int roundingMode = FPSCR_ROUNDING_MODE(tsk->thread.xstate->hardfpu.fpscr);
+	return roundingMode;
+}
+
+BUILD_TRAP_HANDLER(fpu_error)
+{
+	struct task_struct *tsk = current;
+	TRAP_HANDLER_DECL;
+
+	__unlazy_fpu(tsk, regs);
+	fpu_exception_flags = 0;
+	if (ieee_fpe_handler(regs)) {
+		tsk->thread.xstate->hardfpu.fpscr &=
+		    ~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK);
+		tsk->thread.xstate->hardfpu.fpscr |= fpu_exception_flags;
+		/* Set the FPSCR flag as well as cause bits - simply
+		 * replicate the cause */
+		tsk->thread.xstate->hardfpu.fpscr |= (fpu_exception_flags >> 10);
+		grab_fpu(regs);
+		restore_fpu(tsk);
+		task_thread_info(tsk)->status |= TS_USEDFPU;
+		if ((((tsk->thread.xstate->hardfpu.fpscr & FPSCR_ENABLE_MASK) >> 7) &
+		     (fpu_exception_flags >> 2)) == 0) {
+			return;
+		}
+	}
+
+	force_sig(SIGFPE);
+}