[SPARC64]: Handle unimplemented FPU square-root on Niagara.

The math-emu code only expects unfinished fpop traps when
emulating FPU sqrt instructions on pre-Niagara chips.
On Niagara we can get unimplemented fpop, so handle that.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 23 insertions, 2 deletions

diff --git a/arch/sparc64/math-emu/math.c b/arch/sparc64/math-emu/math.c
index 2ae05cd7b77..a93a3664c85 100644
--- a/arch/sparc64/math-emu/math.c
+++ b/arch/sparc64/math-emu/math.c
@@ -206,9 +206,30 @@ int do_mathemu(struct pt_regs *regs, struct fpustate *f)
                         case FSTOQ: TYPE(3,3,1,1,1,0,0); break;
                         case FDTOQ: TYPE(3,3,1,2,1,0,0); break;
                         case FQTOI: TYPE(3,1,0,3,1,0,0); break;
+
+                        /* We can get either unimplemented or unfinished
+                         * for these cases.  Pre-Niagara systems generate
+                         * unfinished fpop for SUBNORMAL cases, and Niagara
+                         * always gives unimplemented fpop for fsqrt{s,d}.
+                         */
+                        case FSQRTS: {
+                                unsigned long x = current_thread_info()->xfsr[0];
+
+                                x = (x >> 14) & 0xf;
+                                TYPE(x,1,1,1,1,0,0);
+                                printk("math-emu: type is %08x\n", type);
+                                break;
+                        }
+
+                        case FSQRTD: {
+                                unsigned long x = current_thread_info()->xfsr[0];
+
+                                x = (x >> 14) & 0xf;
+                                TYPE(x,2,1,2,1,0,0);
+                                break;
+                        }
+
                         /* SUBNORMAL - ftt == 2 */
-                        case FSQRTS: TYPE(2,1,1,1,1,0,0); break;
-                        case FSQRTD: TYPE(2,2,1,2,1,0,0); break;
                         case FADDD:
                         case FSUBD:
                         case FMULD: