commit c6e6771b87d4e339d27f1383c8a808ae9b4ee5b8
author Michael Neuling <mikey@neuling.org> Wed Jun 25 14:07:18 2008 +1000
committer Paul Mackerras <paulus@samba.org> Tue Jul 01 11:28:46 2008 +1000
tree 1900b7350ec685c3a31f2233fd88a57e34725b5c
parent 6f3d8e6947ec98e358514fc0f7b2e37fe88a21bb

powerpc: Introduce VSX thread_struct and CONFIG_VSX

The layout of the new VSR registers and how they overlap on top of the
legacy FPR and VR registers is:

                   VSR doubleword 0               VSR doubleword 1
          ----------------------------------------------------------------
  VSR[0]  |             FPR[0]            |                              |
          ----------------------------------------------------------------
  VSR[1]  |             FPR[1]            |                              |
          ----------------------------------------------------------------
          |              ...              |                              |
          |              ...              |                              |
          ----------------------------------------------------------------
  VSR[30] |             FPR[30]           |                              |
          ----------------------------------------------------------------
  VSR[31] |             FPR[31]           |                              |
          ----------------------------------------------------------------
  VSR[32] |                             VR[0]                            |
          ----------------------------------------------------------------
  VSR[33] |                             VR[1]                            |
          ----------------------------------------------------------------
          |                              ...                             |
          |                              ...                             |
          ----------------------------------------------------------------
  VSR[62] |                             VR[30]                           |
          ----------------------------------------------------------------
  VSR[63] |                             VR[31]                           |
          ----------------------------------------------------------------

VSX has 64 128bit registers.  The first 32 regs overlap with the FP
registers and hence extend them with and additional 64 bits.  The
second 32 regs overlap with the VMX registers.

This commit introduces the thread_struct changes required to reflect
this register layout.  Ptrace and signals code is updated so that the
floating point registers are correctly accessed from the thread_struct
when CONFIG_VSX is enabled.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/signal_64.c

diff --git a/arch/powerpc/kernel/signal_64.c b/arch/powerpc/kernel/signal_64.c
index da7c058..a587b33 100644
--- a/arch/powerpc/kernel/signal_64.c
+++ b/arch/powerpc/kernel/signal_64.c
@@ -89,6 +89,10 @@
 #endif
 	unsigned long msr = regs->msr;
 	long err = 0;
+#ifdef CONFIG_VSX
+	double buf[FP_REGS_SIZE];
+	int i;
+#endif
 
 	flush_fp_to_thread(current);
 
@@ -112,11 +116,21 @@
 #else /* CONFIG_ALTIVEC */
 	err |= __put_user(0, &sc->v_regs);
 #endif /* CONFIG_ALTIVEC */
+	flush_fp_to_thread(current);
+#ifdef CONFIG_VSX
+	/* Copy FP to local buffer then write that out */
+	for (i = 0; i < 32 ; i++)
+		buf[i] = current->thread.TS_FPR(i);
+	memcpy(&buf[i], &current->thread.fpscr, sizeof(double));
+	err |= __copy_to_user(&sc->fp_regs, buf, FP_REGS_SIZE);
+#else /* CONFIG_VSX */
+	/* copy fpr regs and fpscr */
+	err |= __copy_to_user(&sc->fp_regs, &current->thread.fpr, FP_REGS_SIZE);
+#endif /* CONFIG_VSX */
 	err |= __put_user(&sc->gp_regs, &sc->regs);
 	WARN_ON(!FULL_REGS(regs));
 	err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
 	err |= __put_user(msr, &sc->gp_regs[PT_MSR]);
-	err |= __copy_to_user(&sc->fp_regs, &current->thread.fpr, FP_REGS_SIZE);
 	err |= __put_user(signr, &sc->signal);
 	err |= __put_user(handler, &sc->handler);
 	if (set != NULL)
@@ -135,6 +149,9 @@
 #ifdef CONFIG_ALTIVEC
 	elf_vrreg_t __user *v_regs;
 #endif
+#ifdef CONFIG_VSX
+	double buf[FP_REGS_SIZE];
+#endif
 	unsigned long err = 0;
 	unsigned long save_r13 = 0;
 	elf_greg_t *gregs = (elf_greg_t *)regs;
@@ -182,8 +199,6 @@
 	 */
 	regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC);
 
-	err |= __copy_from_user(&current->thread.fpr, &sc->fp_regs, FP_REGS_SIZE);
-
 #ifdef CONFIG_ALTIVEC
 	err |= __get_user(v_regs, &sc->v_regs);
 	if (err)
@@ -202,7 +217,18 @@
 	else
 		current->thread.vrsave = 0;
 #endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_VSX
+	/* restore floating point */
+	err |= __copy_from_user(buf, &sc->fp_regs, FP_REGS_SIZE);
+	if (err)
+		return err;
+	for (i = 0; i < 32 ; i++)
+		current->thread.TS_FPR(i) = buf[i];
+	memcpy(&current->thread.fpscr, &buf[i], sizeof(double));
 
+#else
+	err |= __copy_from_user(&current->thread.fpr, &sc->fp_regs, FP_REGS_SIZE);
+#endif
 	return err;
 }