sparc: Add asm/syscall.h

Based upon a patch by Roland McGrath.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

arch/sparc/include/asm/syscall.h

+#ifndef __ASM_SPARC_SYSCALL_H
+#define __ASM_SPARC_SYSCALL_H
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <asm/ptrace.h>
+
+/* The system call number is given by the user in %g1 */
+static inline long syscall_get_nr(struct task_struct *task,
+				  struct pt_regs *regs)
+{
+	int syscall_p = pt_regs_is_syscall(regs);
+
+	return (syscall_p ? regs->u_regs[UREG_G1] : -1L);
+}
+
+static inline void syscall_rollback(struct task_struct *task,
+				    struct pt_regs *regs)
+{
+	/* XXX This needs some thought.  On Sparc we don't
+	 * XXX save away the original %o0 value somewhere.
+	 * XXX Instead we hold it in register %l5 at the top
+	 * XXX level trap frame and pass this down to the signal
+	 * XXX dispatch code which is the only place that value
+	 * XXX ever was needed.
+	 */
+}
+
+#ifdef CONFIG_SPARC32
+static inline bool syscall_has_error(struct pt_regs *regs)
+{
+	return (regs->psr & PSR_C) ? true : false;
+}
+static inline void syscall_set_error(struct pt_regs *regs)
+{
+	regs->psr |= PSR_C;
+}
+static inline void syscall_clear_error(struct pt_regs *regs)
+{
+	regs->psr &= ~PSR_C;
+}
+#else
+static inline bool syscall_has_error(struct pt_regs *regs)
+{
+	return (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY)) ? true : false;
+}
+static inline void syscall_set_error(struct pt_regs *regs)
+{
+	regs->tstate |= (TSTATE_XCARRY | TSTATE_ICARRY);
+}
+static inline void syscall_clear_error(struct pt_regs *regs)
+{
+	regs->tstate &= ~(TSTATE_XCARRY | TSTATE_ICARRY);
+}
+#endif
+
+static inline long syscall_get_error(struct task_struct *task,
+				     struct pt_regs *regs)
+{
+	long val = regs->u_regs[UREG_I0];
+
+	return (syscall_has_error(regs) ? -val : 0);
+}
+
+static inline long syscall_get_return_value(struct task_struct *task,
+					    struct pt_regs *regs)
+{
+	long val = regs->u_regs[UREG_I0];
+
+	return val;
+}
+
+static inline void syscall_set_return_value(struct task_struct *task,
+					    struct pt_regs *regs,
+					    int error, long val)
+{
+	if (error) {
+		syscall_set_error(regs);
+		regs->u_regs[UREG_I0] = -error;
+	} else {
+		syscall_clear_error(regs);
+		regs->u_regs[UREG_I0] = val;
+	}
+}
+
+static inline void syscall_get_arguments(struct task_struct *task,
+					 struct pt_regs *regs,
+					 unsigned int i, unsigned int n,
+					 unsigned long *args)
+{
+	int zero_extend = 0;
+	unsigned int j;
+
+#ifdef CONFIG_SPARC64
+	if (test_tsk_thread_flag(task, TIF_32BIT))
+		zero_extend = 1;
+#endif
+
+	for (j = 0; j < n; j++) {
+		unsigned long val = regs->u_regs[UREG_I0 + i + j];
+
+		if (zero_extend)
+			args[j] = (u32) val;
+		else
+			args[j] = val;
+	}
+}
+
+static inline void syscall_set_arguments(struct task_struct *task,
+					 struct pt_regs *regs,
+					 unsigned int i, unsigned int n,
+					 const unsigned long *args)
+{
+	unsigned int j;
+
+	for (j = 0; j < n; j++)
+		regs->u_regs[UREG_I0 + i + j] = args[j];
+}
+
+#endif /* __ASM_SPARC_SYSCALL_H */