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 %g1 */
   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 bool syscall_has_error(struct pt_regs *regs)
  25 {
  26         return (regs->sr & 0x1) ? true : false;
  27 }
  28 static inline void syscall_set_error(struct pt_regs *regs)
  29 {
  30         regs->sr |= 0x1;
  31 }
  32 static inline void syscall_clear_error(struct pt_regs *regs)
  33 {
  34         regs->sr &= ~0x1;
  35 }
  36
  37 static inline long syscall_get_error(struct task_struct *task,
  38                                      struct pt_regs *regs)
  39 {
  40         return syscall_has_error(regs) ? regs->regs[0] : 0;
  41 }
  42
  43 static inline long syscall_get_return_value(struct task_struct *task,
  44                                             struct pt_regs *regs)
  45 {
  46         return regs->regs[0];
  47 }
  48
  49 static inline void syscall_set_return_value(struct task_struct *task,
  50                                             struct pt_regs *regs,
  51                                             int error, long val)
  52 {
  53         if (error) {
  54                 syscall_set_error(regs);
  55                 regs->regs[0] = -error;
  56         } else {
  57                 syscall_clear_error(regs);
  58                 regs->regs[0] = val;
  59         }
  60 }
  61
  62 static inline void syscall_get_arguments(struct task_struct *task,
  63                                          struct pt_regs *regs,
  64                                          unsigned int i, unsigned int n,
  65                                          unsigned long *args)
  66 {
  67         /*
  68          * Do this simply for now. If we need to start supporting
  69          * fetching arguments from arbitrary indices, this will need some
  70          * extra logic. Presently there are no in-tree users that depend
  71          * on this behaviour.
  72          */
  73         BUG_ON(i);
  74
  75         /* Argument pattern is: R4, R5, R6, R7, R0, R1 */
  76         switch (n) {
  77         case 6: args[5] = regs->regs[1];
  78         case 5: args[4] = regs->regs[0];
  79         case 4: args[3] = regs->regs[7];
  80         case 3: args[2] = regs->regs[6];
  81         case 2: args[1] = regs->regs[5];
  82         case 1: args[0] = regs->regs[4];
  83                 break;
  84         default:
  85                 BUG();
  86         }
  87 }
  88
  89 static inline void syscall_set_arguments(struct task_struct *task,
  90                                          struct pt_regs *regs,
  91                                          unsigned int i, unsigned int n,
  92                                          const unsigned long *args)
  93 {
  94         /* Same note as above applies */
  95         BUG_ON(i);
  96
  97         switch (n) {
  98         case 6: regs->regs[1] = args[5];
  99         case 5: regs->regs[0] = args[4];
 100         case 4: regs->regs[7] = args[3];
 101         case 3: regs->regs[6] = args[2];
 102         case 2: regs->regs[5] = args[1];
 103         case 1: regs->regs[4] = args[0];
 104                 break;
 105         default:
 106                 BUG();
 107         }
 108 }
 109
 110 #endif /* __ASM_SH_SYSCALL_32_H */