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-rw-r--r--arch/s390/kernel/traps.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index e3e06a4fdfce..9ff5ecba26ab 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -18,6 +18,8 @@
#include <linux/ptrace.h>
#include <linux/sched.h>
#include <linux/mm.h>
+#include <linux/slab.h>
+#include <asm/switch_to.h>
#include "entry.h"
int show_unhandled_signals = 1;
@@ -303,6 +305,74 @@ DO_ERROR_INFO(specification_exception, SIGILL, ILL_ILLOPN,
"specification exception");
#endif
+#ifdef CONFIG_64BIT
+int alloc_vector_registers(struct task_struct *tsk)
+{
+ __vector128 *vxrs;
+ int i;
+
+ /* Allocate vector register save area. */
+ vxrs = kzalloc(sizeof(__vector128) * __NUM_VXRS,
+ GFP_KERNEL|__GFP_REPEAT);
+ if (!vxrs)
+ return -ENOMEM;
+ preempt_disable();
+ if (tsk == current)
+ save_fp_regs(tsk->thread.fp_regs.fprs);
+ /* Copy the 16 floating point registers */
+ for (i = 0; i < 16; i++)
+ *(freg_t *) &vxrs[i] = tsk->thread.fp_regs.fprs[i];
+ tsk->thread.vxrs = vxrs;
+ if (tsk == current) {
+ __ctl_set_bit(0, 17);
+ restore_vx_regs(vxrs);
+ }
+ preempt_enable();
+ return 0;
+}
+
+void vector_exception(struct pt_regs *regs)
+{
+ int si_code, vic;
+
+ if (!MACHINE_HAS_VX) {
+ do_trap(regs, SIGILL, ILL_ILLOPN, "illegal operation");
+ return;
+ }
+
+ /* get vector interrupt code from fpc */
+ asm volatile("stfpc %0" : "=m" (current->thread.fp_regs.fpc));
+ vic = (current->thread.fp_regs.fpc & 0xf00) >> 8;
+ switch (vic) {
+ case 1: /* invalid vector operation */
+ si_code = FPE_FLTINV;
+ break;
+ case 2: /* division by zero */
+ si_code = FPE_FLTDIV;
+ break;
+ case 3: /* overflow */
+ si_code = FPE_FLTOVF;
+ break;
+ case 4: /* underflow */
+ si_code = FPE_FLTUND;
+ break;
+ case 5: /* inexact */
+ si_code = FPE_FLTRES;
+ break;
+ default: /* unknown cause */
+ si_code = 0;
+ }
+ do_trap(regs, SIGFPE, si_code, "vector exception");
+}
+
+static int __init disable_vector_extension(char *str)
+{
+ S390_lowcore.machine_flags &= ~MACHINE_FLAG_VX;
+ return 1;
+}
+__setup("novx", disable_vector_extension);
+#endif
+
void data_exception(struct pt_regs *regs)
{
__u16 __user *location;
@@ -368,6 +438,18 @@ void data_exception(struct pt_regs *regs)
}
}
#endif
+#ifdef CONFIG_64BIT
+ /* Check for vector register enablement */
+ if (MACHINE_HAS_VX && !current->thread.vxrs &&
+ (current->thread.fp_regs.fpc & FPC_DXC_MASK) == 0xfe00) {
+ alloc_vector_registers(current);
+ /* Vector data exception is suppressing, rewind psw. */
+ regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16);
+ clear_pt_regs_flag(regs, PIF_PER_TRAP);
+ return;
+ }
+#endif
+
if (current->thread.fp_regs.fpc & FPC_DXC_MASK)
signal = SIGFPE;
else

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