MIPS: microMIPS: Floating point support.

Add logic needed to do floating point emulation in microMIPS mode.

Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Signed-off-by: Steven J. Hill <Steven. Hill@imgtec.com>

1 files changed, 18 insertions, 4 deletions

diff --git a/arch/mips/kernel/unaligned.c b/arch/mips/kernel/unaligned.c
index 6087a54c86a0..f4c94ff3e3d3 100644
--- a/arch/mips/kernel/unaligned.c
+++ b/arch/mips/kernel/unaligned.c
@@ -83,6 +83,8 @@
 #include <asm/branch.h>
 #include <asm/byteorder.h>
 #include <asm/cop2.h>
+#include <asm/fpu.h>
+#include <asm/fpu_emulator.h>
 #include <asm/inst.h>
 #include <asm/uaccess.h>
 
@@ -108,6 +110,7 @@ static void emulate_load_store_insn(struct pt_regs *regs,
         union mips_instruction insn;
         unsigned long value;
         unsigned int res;
+        void __user *fault_addr = NULL;
 
         perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 
@@ -447,10 +450,21 @@ static void emulate_load_store_insn(struct pt_regs *regs,
         case ldc1_op:
         case swc1_op:
         case sdc1_op:
-                /*
-                 * I herewith declare: this does not happen.  So send SIGBUS.
-                 */
-                goto sigbus;
+                die_if_kernel("Unaligned FP access in kernel code", regs);
+                BUG_ON(!used_math());
+                BUG_ON(!is_fpu_owner());
+
+                lose_fpu(1);    /* Save FPU state for the emulator. */
+                res = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
+                                               &fault_addr);
+                own_fpu(1);     /* Restore FPU state. */
+
+                /* Signal if something went wrong. */
+                process_fpemu_return(res, fault_addr);
+
+                if (res == 0)
+                        break;
+                return;
 
         /*
          * COP2 is available to implementor for application specific use.