sh: math-emu support

[pandora-kernel.git] / arch / sh / kernel / traps.c

diff --git a/arch/sh/kernel/traps.c b/arch/sh/kernel/traps.c
index 21bef1b..95c810b 100644 (file)
--- a/arch/sh/kernel/traps.c
+++ b/arch/sh/kernel/traps.c
@@ -36,40 +36,15 @@
 
 #ifdef CONFIG_SH_KGDB
 #include <asm/kgdb.h>
-#define CHK_REMOTE_DEBUG(regs)                                               \
-{                                                                            \
-  if ((kgdb_debug_hook != (kgdb_debug_hook_t *) NULL) && (!user_mode(regs))) \
-  {                                                                          \
-    (*kgdb_debug_hook)(regs);                                                \
-  }                                                                          \
+#define CHK_REMOTE_DEBUG(regs)                         \
+{                                              \
+       if (kgdb_debug_hook && !user_mode(regs))\
+               (*kgdb_debug_hook)(regs);       \
 }
 #else
 #define CHK_REMOTE_DEBUG(regs)
 #endif
 
-#define DO_ERROR(trapnr, signr, str, name, tsk)                                \
-asmlinkage void do_##name(unsigned long r4, unsigned long r5,          \
-                         unsigned long r6, unsigned long r7,           \
-                         struct pt_regs regs)                          \
-{                                                                      \
-       unsigned long error_code;                                       \
-                                                                       \
-       /* Check if it's a DSP instruction */                           \
-       if (is_dsp_inst(&regs)) {                                       \
-               /* Enable DSP mode, and restart instruction. */         \
-               regs.sr |= SR_DSP;                                      \
-               return;                                                 \
-       }                                                               \
-                                                                       \
-       asm volatile("stc       r2_bank, %0": "=r" (error_code));       \
-       local_irq_enable();                                             \
-       tsk->thread.error_code = error_code;                            \
-       tsk->thread.trap_no = trapnr;                                   \
-        CHK_REMOTE_DEBUG(&regs);                                       \
-       force_sig(signr, tsk);                                          \
-       die_if_no_fixup(str,&regs,error_code);                          \
-}
-
 #ifdef CONFIG_CPU_SH2
 #define TRAP_RESERVED_INST     4
 #define TRAP_ILLEGAL_SLOT_INST 6
@@ -575,8 +550,117 @@ int is_dsp_inst(struct pt_regs *regs)
 #define is_dsp_inst(regs)      (0)
 #endif /* CONFIG_SH_DSP */
 
-DO_ERROR(TRAP_RESERVED_INST, SIGILL, "reserved instruction", reserved_inst, current)
-DO_ERROR(TRAP_ILLEGAL_SLOT_INST, SIGILL, "illegal slot instruction", illegal_slot_inst, current)
+extern int do_fpu_inst(unsigned short, struct pt_regs*);
+
+asmlinkage void do_reserved_inst(unsigned long r4, unsigned long r5,
+                               unsigned long r6, unsigned long r7,
+                               struct pt_regs regs)
+{
+       unsigned long error_code;
+       struct task_struct *tsk = current;
+
+#ifdef CONFIG_SH_FPU_EMU
+       unsigned short inst;
+       int err;
+
+       get_user(inst, (unsigned short*)regs.pc);
+
+       err = do_fpu_inst(inst, &regs);
+       if (!err) {
+               regs.pc += 2;
+               return;
+       }
+       /* not a FPU inst. */
+#endif
+
+#ifdef CONFIG_SH_DSP
+       /* Check if it's a DSP instruction */
+       if (is_dsp_inst(&regs)) {
+               /* Enable DSP mode, and restart instruction. */
+               regs.sr |= SR_DSP;
+               return;
+       }
+#endif
+
+       asm volatile("stc       r2_bank, %0": "=r" (error_code));
+       local_irq_enable();
+       tsk->thread.error_code = error_code;
+       tsk->thread.trap_no = TRAP_RESERVED_INST;
+       CHK_REMOTE_DEBUG(&regs);
+       force_sig(SIGILL, tsk);
+       die_if_no_fixup("reserved instruction", &regs, error_code);
+}
+
+#ifdef CONFIG_SH_FPU_EMU
+static int emulate_branch(unsigned short inst, struct pt_regs* regs)
+{
+       /*
+        * bfs: 8fxx: PC+=d*2+4;
+        * bts: 8dxx: PC+=d*2+4;
+        * bra: axxx: PC+=D*2+4;
+        * bsr: bxxx: PC+=D*2+4  after PR=PC+4;
+        * braf:0x23: PC+=Rn*2+4;
+        * bsrf:0x03: PC+=Rn*2+4 after PR=PC+4;
+        * jmp: 4x2b: PC=Rn;
+        * jsr: 4x0b: PC=Rn      after PR=PC+4;
+        * rts: 000b: PC=PR;
+        */
+       if ((inst & 0xfd00) == 0x8d00) {
+               regs->pc += SH_PC_8BIT_OFFSET(inst);
+               return 0;
+       }
+
+       if ((inst & 0xe000) == 0xa000) {
+               regs->pc += SH_PC_12BIT_OFFSET(inst);
+               return 0;
+       }
+
+       if ((inst & 0xf0df) == 0x0003) {
+               regs->pc += regs->regs[(inst & 0x0f00) >> 8] + 4;
+               return 0;
+       }
+
+       if ((inst & 0xf0df) == 0x400b) {
+               regs->pc = regs->regs[(inst & 0x0f00) >> 8];
+               return 0;
+       }
+
+       if ((inst & 0xffff) == 0x000b) {
+               regs->pc = regs->pr;
+               return 0;
+       }
+
+       return 1;
+}
+#endif
+
+asmlinkage void do_illegal_slot_inst(unsigned long r4, unsigned long r5,
+                               unsigned long r6, unsigned long r7,
+                               struct pt_regs regs)
+{
+       unsigned long error_code;
+       struct task_struct *tsk = current;
+#ifdef CONFIG_SH_FPU_EMU
+       unsigned short inst;
+
+       get_user(inst, (unsigned short *)regs.pc + 1);
+       if (!do_fpu_inst(inst, &regs)) {
+               get_user(inst, (unsigned short *)regs.pc);
+               if (!emulate_branch(inst, &regs))
+                       return;
+               /* fault in branch.*/
+       }
+       /* not a FPU inst. */
+#endif
+
+       asm volatile("stc       r2_bank, %0": "=r" (error_code));
+       local_irq_enable();
+       tsk->thread.error_code = error_code;
+       tsk->thread.trap_no = TRAP_RESERVED_INST;
+       CHK_REMOTE_DEBUG(&regs);
+       force_sig(SIGILL, tsk);
+       die_if_no_fixup("illegal slot instruction", &regs, error_code);
+}
 
 asmlinkage void do_exception_error(unsigned long r4, unsigned long r5,
                                   unsigned long r6, unsigned long r7,
@@ -634,14 +718,16 @@ void __init trap_init(void)
        exception_handling_table[TRAP_ILLEGAL_SLOT_INST]
                = (void *)do_illegal_slot_inst;
 
-#ifdef CONFIG_CPU_SH4
-       if (!(cpu_data->flags & CPU_HAS_FPU)) {
-               /* For SH-4 lacking an FPU, treat floating point instructions
-                  as reserved. */
-               /* entry 64 corresponds to EXPEVT=0x800 */
-               exception_handling_table[64] = (void *)do_reserved_inst;
-               exception_handling_table[65] = (void *)do_illegal_slot_inst;
-       }
+#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SH_FPU) || \
+    defined(CONFIG_SH_FPU_EMU)
+       /*
+        * For SH-4 lacking an FPU, treat floating point instructions as
+        * reserved. They'll be handled in the math-emu case, or faulted on
+        * otherwise.
+        */
+       /* entry 64 corresponds to EXPEVT=0x800 */
+       exception_handling_table[64] = (void *)do_reserved_inst;
+       exception_handling_table[65] = (void *)do_illegal_slot_inst;
 #endif
                
        /* Setup VBR for boot cpu */