PPC32: add support for restarting syscalls with ERESTART_RESTARTBLOCK

arch/ppc/kernel/misc.S

@@ -1056,7 +1056,7 @@ SYSCALL(waitpid)
 	.data
 	.align 4
 _GLOBAL(sys_call_table)
-	.long sys_ni_syscall	/* 0  -  old "setup()" system call */
+	.long sys_restart_syscall /* 0 */
 	.long sys_exit
 	.long ppc_fork
 	.long sys_read

arch/ppc/kernel/signal.c

@@ -393,8 +393,12 @@ handle_signal(unsigned long sig, siginfo_t *info, sigset_t *oldset,
 
 	if (TRAP(regs) == 0x0C00 /* System Call! */
 	    && ((int)regs->result == -ERESTARTNOHAND ||
+		(int)regs->result == -ERESTART_RESTARTBLOCK ||
 		((int)regs->result == -ERESTARTSYS &&
 		 !(ka->sa.sa_flags & SA_RESTART)))) {
+		if ((int)regs->result == -ERESTART_RESTARTBLOCK)
+			current_thread_info()->restart_block.fn
+				= do_no_restart_syscall;
 		regs->result = -EINTR;
 		regs->gpr[3] = EINTR;
 		regs->ccr |= 0x10000000;
@@ -494,13 +498,18 @@ int do_signal(sigset_t *oldset, struct pt_regs *regs)
 		handle_signal(signr, &info, oldset, regs, &newsp, frame);
 	}
 
-	if (TRAP(regs) == 0x0C00 /* System Call! */ &&
-	    ((int)regs->result == -ERESTARTNOHAND ||
+	if (TRAP(regs) == 0x0C00) {	/* System Call! */
+		if ((int)regs->result == -ERESTARTNOHAND ||
 		    (int)regs->result == -ERESTARTSYS ||
-	     (int)regs->result == -ERESTARTNOINTR)) {
+		    (int)regs->result == -ERESTARTNOINTR) {
 			regs->gpr[3] = regs->orig_gpr3;
 			regs->nip -= 4;	/* Back up & retry system call */
 			regs->result = 0;
+		} else if ((int)regs->result == -ERESTART_RESTARTBLOCK) {
+			regs->gpr[0] = __NR_restart_syscall;
+			regs->nip -= 4;
+			regs->result = 0;
+		}
 	}
 
 	if (newsp == frame)

include/asm-ppc/errno.h

@@ -6,12 +6,6 @@
 #undef	EDEADLOCK
 #define	EDEADLOCK	58	/* File locking deadlock error */
 
-/* Should never be seen by user programs */
-#define ERESTARTSYS	512
-#define ERESTARTNOINTR	513
-#define ERESTARTNOHAND	514	/* restart if no handler.. */
-#define ENOIOCTLCMD	515	/* No ioctl command */
-
-#define _LAST_ERRNO	515
+#define _LAST_ERRNO	516
 
 #endif

include/asm-ppc/thread_info.h

@@ -23,6 +23,7 @@ struct thread_info {
 	unsigned long		flags;		/* low level flags */
 	int			cpu;		/* cpu we're on */
 	int			preempt_count;
+	struct restart_block	restart_block;
 };
 
 #define INIT_THREAD_INFO(tsk)			\
@@ -31,7 +32,10 @@ struct thread_info {
 	.exec_domain =	&default_exec_domain,	\
 	.flags =	0,			\
 	.cpu =		0,			\
-	.preempt_count = 1			\
+	.preempt_count = 1,			\
+	.restart_block = {			\
+		.fn = do_no_restart_syscall,	\
+	},					\
 }
 
 #define init_thread_info	(init_thread_union.thread_info)
@@ -70,8 +74,6 @@ static inline struct thread_info *current_thread_info(void)
 #define TI_FLAGS	8
 #define TI_CPU		12
 #define TI_PREEMPT	16
-#define TI_SOFTIRQ	20
-#define TI_HARDIRQ	24
 
 #define PREEMPT_ACTIVE		0x4000000
 

include/asm-ppc/unistd.h

@@ -4,7 +4,7 @@
 /*
  * This file contains the system call numbers.
  */
-
+#define __NR_restart_syscall	  0
 #define __NR_exit		  1
 #define __NR_fork		  2
 #define __NR_read		  3