1 files changed, 96 insertions, 0 deletions

diff --git a/arch/blackfin/include/asm/syscall.h b/arch/blackfin/include/asm/syscall.h
new file mode 100644
index 000000000000..4921a4815cce
--- /dev/null
+++ b/arch/blackfin/include/asm/syscall.h
@@ -0,0 +1,96 @@
+/*
+ * Magic syscall break down functions
+ *
+ * Copyright 2010 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#ifndef __ASM_BLACKFIN_SYSCALL_H__
+#define __ASM_BLACKFIN_SYSCALL_H__
+
+/*
+ * Blackfin syscalls are simple:
+ *      enter:
+ *              p0: syscall number
+ *              r{0,1,2,3,4,5}: syscall args 0,1,2,3,4,5
+ *      exit:
+ *              r0: return/error value
+ */
+
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <asm/ptrace.h>
+
+static inline long
+syscall_get_nr(struct task_struct *task, struct pt_regs *regs)
+{
+        return regs->p0;
+}
+
+static inline void
+syscall_rollback(struct task_struct *task, struct pt_regs *regs)
+{
+        regs->p0 = regs->orig_p0;
+}
+
+static inline long
+syscall_get_error(struct task_struct *task, struct pt_regs *regs)
+{
+        return IS_ERR_VALUE(regs->r0) ? regs->r0 : 0;
+}
+
+static inline long
+syscall_get_return_value(struct task_struct *task, struct pt_regs *regs)
+{
+        return regs->r0;
+}
+
+static inline void
+syscall_set_return_value(struct task_struct *task, struct pt_regs *regs,
+                         int error, long val)
+{
+        regs->r0 = error ? -error : val;
+}
+
+/**
+ *      syscall_get_arguments()
+ *      @task:   unused
+ *      @regs:   the register layout to extract syscall arguments from
+ *      @i:      first syscall argument to extract
+ *      @n:      number of syscall arguments to extract
+ *      @args:   array to return the syscall arguments in
+ *
+ * args[0] gets i'th argument, args[n - 1] gets the i+n-1'th argument
+ */
+static inline void
+syscall_get_arguments(struct task_struct *task, struct pt_regs *regs,
+                      unsigned int i, unsigned int n, unsigned long *args)
+{
+        /*
+         * Assume the ptrace layout doesn't change -- r5 is first in memory,
+         * then r4, ..., then r0.  So we simply reverse the ptrace register
+         * array in memory to store into the args array.
+         */
+        long *aregs = &regs->r0 - i;
+
+        BUG_ON(i > 5 || i + n > 6);
+
+        while (n--)
+                *args++ = *aregs--;
+}
+
+/* See syscall_get_arguments() comments */
+static inline void
+syscall_set_arguments(struct task_struct *task, struct pt_regs *regs,
+                      unsigned int i, unsigned int n, const unsigned long *args)
+{
+        long *aregs = &regs->r0 - i;
+
+        BUG_ON(i > 5 || i + n > 6);
+
+        while (n--)
+                *aregs-- = *args++;
+}
+
+#endif