+static inline void
+syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
+{
+ /* Check the return code */
+ switch (regs->gr[28]) {
+ case -ERESTART_RESTARTBLOCK:
+ current_thread_info()->restart_block.fn =
+ do_no_restart_syscall;
+ case -ERESTARTNOHAND:
+ DBG(1,"ERESTARTNOHAND: returning -EINTR\n");
+ regs->gr[28] = -EINTR;
+ break;
+
+ case -ERESTARTSYS:
+ if (!(ka->sa.sa_flags & SA_RESTART)) {
+ DBG(1,"ERESTARTSYS: putting -EINTR\n");
+ regs->gr[28] = -EINTR;
+ break;
+ }
+ /* fallthrough */
+ case -ERESTARTNOINTR:
+ /* A syscall is just a branch, so all
+ * we have to do is fiddle the return pointer.
+ */
+ regs->gr[31] -= 8; /* delayed branching */
+ /* Preserve original r28. */
+ regs->gr[28] = regs->orig_r28;
+ break;
+ }
+}
+
+static inline void
+insert_restart_trampoline(struct pt_regs *regs)
+{
+ switch(regs->gr[28]) {
+ case -ERESTART_RESTARTBLOCK: {
+ /* Restart the system call - no handlers present */
+ unsigned int *usp = (unsigned int *)regs->gr[30];
+
+ /* Setup a trampoline to restart the syscall
+ * with __NR_restart_syscall
+ *
+ * 0: <return address (orig r31)>
+ * 4: <2nd half for 64-bit>
+ * 8: ldw 0(%sp), %r31
+ * 12: be 0x100(%sr2, %r0)
+ * 16: ldi __NR_restart_syscall, %r20
+ */
+#ifdef CONFIG_64BIT
+ put_user(regs->gr[31] >> 32, &usp[0]);
+ put_user(regs->gr[31] & 0xffffffff, &usp[1]);
+ put_user(0x0fc010df, &usp[2]);
+#else
+ put_user(regs->gr[31], &usp[0]);
+ put_user(0x0fc0109f, &usp[2]);
+#endif
+ put_user(0xe0008200, &usp[3]);
+ put_user(0x34140000, &usp[4]);
+
+ /* Stack is 64-byte aligned, and we only need
+ * to flush 1 cache line.
+ * Flushing one cacheline is cheap.
+ * "sync" on bigger (> 4 way) boxes is not.
+ */
+ flush_user_dcache_range(regs->gr[30], regs->gr[30] + 4);
+ flush_user_icache_range(regs->gr[30], regs->gr[30] + 4);
+
+ regs->gr[31] = regs->gr[30] + 8;
+ /* Preserve original r28. */
+ regs->gr[28] = regs->orig_r28;
+
+ return;
+ }
+ case -ERESTARTNOHAND:
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR: {
+ /* Hooray for delayed branching. We don't
+ * have to restore %r20 (the system call
+ * number) because it gets loaded in the delay
+ * slot of the branch external instruction.
+ */
+ regs->gr[31] -= 8;
+ /* Preserve original r28. */
+ regs->gr[28] = regs->orig_r28;
+
+ return;
+ }
+ default:
+ break;
+ }
+}
+