Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 335 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 00000000000..f486c07e10e
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4/fpu.c
@@ -0,0 +1,335 @@
+/* $Id: fpu.c,v 1.4 2004/01/13 05:52:11 kkojima Exp $
+ *
+ * linux/arch/sh/kernel/fpu.c
+ *
+ * Save/restore floating point context for signal handlers.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
+ *
+ * FIXME! These routines can be optimized in big endian case.
+ */
+
+#include <linux/sched.h>
+#include <linux/signal.h>
+#include <asm/processor.h>
+#include <asm/io.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
+
+
+/*
+ * Save FPU registers onto task structure.
+ * Assume called with FPU enabled (SR.FD=0).
+ */
+void
+save_fpu(struct task_struct *tsk, struct pt_regs *regs)
+{
+	unsigned long dummy;
+
+	clear_tsk_thread_flag(tsk, TIF_USEDFPU);
+	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.fpu.hard.status)),
+		       "r" (FPSCR_RCHG),
+		       "r" (FPSCR_INIT)
+		     : "memory");
+
+ 	disable_fpu();
+ 	release_fpu(regs);
+}
+
+static 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.fpu), "r" (FPSCR_RCHG)
+		     : "memory");
+	disable_fpu();
+}
+
+/*
+ * Load the FPU with signalling NANS.  This bit pattern we're using
+ * has the property that no matter wether considered as single or as
+ * double precission represents signaling NANS.  
+ */
+
+static void
+fpu_init(void)
+{
+	enable_fpu();
+	asm volatile("lds	%0, fpul\n\t"
+		     "lds	%1, fpscr\n\t"
+		     "fsts	fpul, fr0\n\t"
+		     "fsts	fpul, fr1\n\t"
+		     "fsts	fpul, fr2\n\t"
+		     "fsts	fpul, fr3\n\t"
+		     "fsts	fpul, fr4\n\t"
+		     "fsts	fpul, fr5\n\t"
+		     "fsts	fpul, fr6\n\t"
+		     "fsts	fpul, fr7\n\t"
+		     "fsts	fpul, fr8\n\t"
+		     "fsts	fpul, fr9\n\t"
+		     "fsts	fpul, fr10\n\t"
+		     "fsts	fpul, fr11\n\t"
+		     "fsts	fpul, fr12\n\t"
+		     "fsts	fpul, fr13\n\t"
+		     "fsts	fpul, fr14\n\t"
+		     "fsts	fpul, fr15\n\t"
+		     "frchg\n\t"
+		     "fsts	fpul, fr0\n\t"
+		     "fsts	fpul, fr1\n\t"
+		     "fsts	fpul, fr2\n\t"
+		     "fsts	fpul, fr3\n\t"
+		     "fsts	fpul, fr4\n\t"
+		     "fsts	fpul, fr5\n\t"
+		     "fsts	fpul, fr6\n\t"
+		     "fsts	fpul, fr7\n\t"
+		     "fsts	fpul, fr8\n\t"
+		     "fsts	fpul, fr9\n\t"
+		     "fsts	fpul, fr10\n\t"
+		     "fsts	fpul, fr11\n\t"
+		     "fsts	fpul, fr12\n\t"
+		     "fsts	fpul, fr13\n\t"
+		     "fsts	fpul, fr14\n\t"
+		     "fsts	fpul, fr15\n\t"
+		     "frchg\n\t"
+		     "lds	%2, fpscr\n\t"
+		     : /* no output */
+		     : "r" (0), "r" (FPSCR_RCHG), "r" (FPSCR_INIT));
+ 	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)) /* bsr & jsr */
+		regs->pr = regs->pc + 4;
+  
+	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 + 2;
+		finsn = insn;
+	}
+
+	if ((finsn & 0xf1ff) == 0xf0ad) { /* fcnvsd */
+		struct task_struct *tsk = current;
+
+		save_fpu(tsk, regs);
+		if ((tsk->thread.fpu.hard.fpscr & (1 << 17))) {
+			/* FPU error */
+			denormal_to_double (&tsk->thread.fpu.hard,
+					    (finsn >> 8) & 0xf);
+			tsk->thread.fpu.hard.fpscr &=
+				~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK);
+			grab_fpu(regs);
+			restore_fpu(tsk);
+			set_tsk_thread_flag(tsk, TIF_USEDFPU);
+		} else {
+			tsk->thread.trap_no = 11;
+			tsk->thread.error_code = 0;
+			force_sig(SIGFPE, tsk);
+		}
+
+		regs->pc = nextpc;
+		return 1;
+	}
+
+	return 0;
+}
+
+asmlinkage void
+do_fpu_error(unsigned long r4, unsigned long r5, unsigned long r6, unsigned long r7,
+	     struct pt_regs regs)
+{
+	struct task_struct *tsk = current;
+
+	if (ieee_fpe_handler (&regs))
+		return;
+
+	regs.pc += 2;
+	save_fpu(tsk, &regs);
+	tsk->thread.trap_no = 11;
+	tsk->thread.error_code = 0;
+	force_sig(SIGFPE, tsk);
+}
+
+asmlinkage void
+do_fpu_state_restore(unsigned long r4, unsigned long r5, unsigned long r6,
+		     unsigned long r7, struct pt_regs regs)
+{
+	struct task_struct *tsk = current;
+
+	grab_fpu(&regs);
+	if (!user_mode(&regs)) {
+		printk(KERN_ERR "BUG: FPU is used in kernel mode.\n");
+		return;
+	}
+
+	if (used_math()) {
+		/* Using the FPU again.  */
+		restore_fpu(tsk);
+	} else	{
+		/* First time FPU user.  */
+		fpu_init();
+		set_used_math();
+	}
+	set_tsk_thread_flag(tsk, TIF_USEDFPU);
+}