summaryrefslogtreecommitdiffstats
path: root/arch/arm/kvm/hyp/vfp.S
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/kvm/hyp/vfp.S')
-rw-r--r--arch/arm/kvm/hyp/vfp.S68
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/arm/kvm/hyp/vfp.S b/arch/arm/kvm/hyp/vfp.S
new file mode 100644
index 000000000000..7c297e87eb8b
--- /dev/null
+++ b/arch/arm/kvm/hyp/vfp.S
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/linkage.h>
+#include <asm/vfpmacros.h>
+
+ .text
+ .pushsection .hyp.text, "ax"
+
+/* void __vfp_save_state(struct vfp_hard_struct *vfp); */
+ENTRY(__vfp_save_state)
+ push {r4, r5}
+ VFPFMRX r1, FPEXC
+
+ @ Make sure *really* VFP is enabled so we can touch the registers.
+ orr r5, r1, #FPEXC_EN
+ tst r5, #FPEXC_EX @ Check for VFP Subarchitecture
+ bic r5, r5, #FPEXC_EX @ FPEXC_EX disable
+ VFPFMXR FPEXC, r5
+ isb
+
+ VFPFMRX r2, FPSCR
+ beq 1f
+
+ @ If FPEXC_EX is 0, then FPINST/FPINST2 reads are upredictable, so
+ @ we only need to save them if FPEXC_EX is set.
+ VFPFMRX r3, FPINST
+ tst r5, #FPEXC_FP2V
+ VFPFMRX r4, FPINST2, ne @ vmrsne
+1:
+ VFPFSTMIA r0, r5 @ Save VFP registers
+ stm r0, {r1-r4} @ Save FPEXC, FPSCR, FPINST, FPINST2
+ pop {r4, r5}
+ bx lr
+ENDPROC(__vfp_save_state)
+
+/* void __vfp_restore_state(struct vfp_hard_struct *vfp);
+ * Assume FPEXC_EN is on and FPEXC_EX is off */
+ENTRY(__vfp_restore_state)
+ VFPFLDMIA r0, r1 @ Load VFP registers
+ ldm r0, {r0-r3} @ Load FPEXC, FPSCR, FPINST, FPINST2
+
+ VFPFMXR FPSCR, r1
+ tst r0, #FPEXC_EX @ Check for VFP Subarchitecture
+ beq 1f
+ VFPFMXR FPINST, r2
+ tst r0, #FPEXC_FP2V
+ VFPFMXR FPINST2, r3, ne
+1:
+ VFPFMXR FPEXC, r0 @ FPEXC (last, in case !EN)
+ bx lr
+ENDPROC(__vfp_restore_state)
+
+ .popsection