arch/sh/include/asm/syscall_32.h

   1 #ifndef __ASM_SH_SYSCALL_32_H
   2 #define __ASM_SH_SYSCALL_32_H
   3
   4 #include <linux/kernel.h>
   5 #include <linux/sched.h>
   6 #include <asm/ptrace.h>
   7
   8 /* The system call number is given by the user in R3 */
   9 static inline long syscall_get_nr(struct task_struct *task,
  10                                   struct pt_regs *regs)
  11 {
  12         return (regs->tra >= 0) ? regs->regs[3] : -1L;
  13 }
  14
  15 static inline void syscall_rollback(struct task_struct *task,
  16                                     struct pt_regs *regs)
  17 {
  18         /*
  19          * XXX: This needs some thought. On SH we don't
  20          * save away the original r0 value anywhere.
  21          */
  22 }
  23
  24 static inline long syscall_get_error(struct task_struct *task,
  25                                      struct pt_regs *regs)
  26 {
  27         return IS_ERR_VALUE(regs->regs[0]) ? regs->regs[0] : 0;
  28 }
  29
  30 static inline long syscall_get_return_value(struct task_struct *task,
  31                                             struct pt_regs *regs)
  32 {
  33         return regs->regs[0];
  34 }
  35
  36 static inline void syscall_set_return_value(struct task_struct *task,
  37                                             struct pt_regs *regs,
  38                                             int error, long val)
  39 {
  40         if (error)
  41                 regs->regs[0] = -error;
  42         else
  43                 regs->regs[0] = val;
  44 }
  45
  46 static inline void syscall_get_arguments(struct task_struct *task,
  47                                          struct pt_regs *regs,
  48                                          unsigned int i, unsigned int n,
  49                                          unsigned long *args)
  50 {
  51         /*
  52          * Do this simply for now. If we need to start supporting
  53          * fetching arguments from arbitrary indices, this will need some
  54          * extra logic. Presently there are no in-tree users that depend
  55          * on this behaviour.
  56          */
  57         BUG_ON(i);
  58
  59         /* Argument pattern is: R4, R5, R6, R7, R0, R1 */
  60         switch (n) {
  61         case 6: args[5] = regs->regs[1];
  62         case 5: args[4] = regs->regs[0];
  63         case 4: args[3] = regs->regs[7];
  64         case 3: args[2] = regs->regs[6];
  65         case 2: args[1] = regs->regs[5];
  66         case 1: args[0] = regs->regs[4];
  67                 break;
  68         default:
  69                 BUG();
  70         }
  71 }
  72
  73 static inline void syscall_set_arguments(struct task_struct *task,
  74                                          struct pt_regs *regs,
  75                                          unsigned int i, unsigned int n,
  76                                          const unsigned long *args)
  77 {
  78         /* Same note as above applies */
  79         BUG_ON(i);
  80
  81         switch (n) {
  82         case 6: regs->regs[1] = args[5];
  83         case 5: regs->regs[0] = args[4];
  84         case 4: regs->regs[7] = args[3];
  85         case 3: regs->regs[6] = args[2];
  86         case 2: regs->regs[5] = args[1];
  87         case 1: regs->regs[4] = args[0];
  88                 break;
  89         default:
  90                 BUG();
  91         }
  92 }
  93
  94 #endif /* __ASM_SH_SYSCALL_32_H */