[PATCH] xtensa: Architecture support for Tensilica Xtensa Part 3

The attached patches provides part 3 of an architecture implementation for the
Tensilica Xtensa CPU series.

Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 418 insertions, 0 deletions

diff --git a/arch/xtensa/kernel/syscalls.c b/arch/xtensa/kernel/syscalls.c
new file mode 100644
index 0000000..abc8ed6
--- /dev/null
+++ b/arch/xtensa/kernel/syscalls.c
@@ -0,0 +1,418 @@
+/*
+ * arch/xtensa/kernel/syscall.c
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2005 Tensilica Inc.
+ * Copyright (C) 2000 Silicon Graphics, Inc.
+ * Copyright (C) 1995 - 2000 by Ralf Baechle
+ *
+ * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
+ * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
+ * Chris Zankel <chris@zankel.net>
+ * Kevin Chea
+ *
+ */
+
+#define DEBUG	0
+
+#include <linux/config.h>
+#include <linux/linkage.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/mman.h>
+#include <linux/sched.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+#include <linux/utsname.h>
+#include <linux/unistd.h>
+#include <linux/stringify.h>
+#include <linux/syscalls.h>
+#include <linux/sem.h>
+#include <linux/msg.h>
+#include <linux/shm.h>
+#include <linux/errno.h>
+#include <asm/ptrace.h>
+#include <asm/signal.h>
+#include <asm/uaccess.h>
+#include <asm/hardirq.h>
+#include <asm/mman.h>
+#include <asm/shmparam.h>
+#include <asm/page.h>
+#include <asm/ipc.h>
+
+extern void do_syscall_trace(void);
+typedef int (*syscall_t)(void *a0,...);
+extern int (*do_syscalls)(struct pt_regs *regs, syscall_t fun,
+				     int narg);
+extern syscall_t sys_call_table[];
+extern unsigned char sys_narg_table[];
+
+/*
+ * sys_pipe() is the normal C calling standard for creating a pipe. It's not
+ * the way unix traditional does this, though.
+ */
+
+int sys_pipe(int __user *userfds)
+{
+	int fd[2];
+	int error;
+
+	error = do_pipe(fd);
+	if (!error) {
+		if (copy_to_user(userfds, fd, 2 * sizeof(int)))
+			error = -EFAULT;
+	}
+	return error;
+}
+
+/*
+ * Common code for old and new mmaps.
+ */
+
+static inline long do_mmap2(unsigned long addr, unsigned long len,
+    			    unsigned long prot, unsigned long flags,
+			    unsigned long fd, unsigned long pgoff)
+{
+	int error = -EBADF;
+	struct file * file = NULL;
+
+	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
+	if (!(flags & MAP_ANONYMOUS)) {
+		file = fget(fd);
+		if (!file)
+			goto out;
+	}
+
+	down_write(&current->mm->mmap_sem);
+	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
+	up_write(&current->mm->mmap_sem);
+
+	if (file)
+		fput(file);
+out:
+	return error;
+}
+
+unsigned long old_mmap(unsigned long addr, size_t len, int prot,
+		       int flags, int fd, off_t offset)
+{
+	return do_mmap2(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);
+}
+
+long sys_mmap2(unsigned long addr, unsigned long len, unsigned long prot,
+	       unsigned long flags, unsigned long fd, unsigned long pgoff)
+{
+	return do_mmap2(addr, len, prot, flags, fd, pgoff);
+}
+
+int sys_fork(struct pt_regs *regs)
+{
+	return do_fork(SIGCHLD, regs->areg[1], regs, 0, NULL, NULL);
+}
+
+int sys_vfork(struct pt_regs *regs)
+{
+	return do_fork(CLONE_VFORK|CLONE_VM|SIGCHLD, regs->areg[1],
+		       regs, 0, NULL, NULL);
+}
+
+int sys_clone(struct pt_regs *regs)
+{
+	unsigned long clone_flags;
+	unsigned long newsp;
+	int __user *parent_tidptr, *child_tidptr;
+	clone_flags = regs->areg[4];
+	newsp = regs->areg[3];
+	parent_tidptr = (int __user *)regs->areg[5];
+	child_tidptr = (int __user *)regs->areg[6];
+	if (!newsp)
+		newsp = regs->areg[1];
+	return do_fork(clone_flags,newsp,regs,0,parent_tidptr,child_tidptr);
+}
+
+/*
+ * sys_execve() executes a new program.
+ */
+
+int sys_execve(struct pt_regs *regs)
+{
+	int error;
+	char * filename;
+
+	filename = getname((char *) (long)regs->areg[5]);
+	error = PTR_ERR(filename);
+	if (IS_ERR(filename))
+		goto out;
+	error = do_execve(filename, (char **) (long)regs->areg[3],
+	                  (char **) (long)regs->areg[4], regs);
+	putname(filename);
+
+out:
+	return error;
+}
+
+int sys_uname(struct old_utsname * name)
+{
+	if (name && !copy_to_user(name, &system_utsname, sizeof (*name)))
+		return 0;
+	return -EFAULT;
+}
+
+int sys_olduname(struct oldold_utsname * name)
+{
+	int error;
+
+	if (!name)
+		return -EFAULT;
+	if (!access_ok(VERIFY_WRITE,name,sizeof(struct oldold_utsname)))
+		return -EFAULT;
+
+	error = __copy_to_user(&name->sysname,&system_utsname.sysname,__OLD_UTS_LEN);
+	error -= __put_user(0,name->sysname+__OLD_UTS_LEN);
+	error -= __copy_to_user(&name->nodename,&system_utsname.nodename,__OLD_UTS_LEN);
+	error -= __put_user(0,name->nodename+__OLD_UTS_LEN);
+	error -= __copy_to_user(&name->release,&system_utsname.release,__OLD_UTS_LEN);
+	error -= __put_user(0,name->release+__OLD_UTS_LEN);
+	error -= __copy_to_user(&name->version,&system_utsname.version,__OLD_UTS_LEN);
+	error -= __put_user(0,name->version+__OLD_UTS_LEN);
+	error -= __copy_to_user(&name->machine,&system_utsname.machine,__OLD_UTS_LEN);
+	error -= __put_user(0,name->machine+__OLD_UTS_LEN);
+
+	return error ? -EFAULT : 0;
+}
+
+
+/*
+ * Build the string table for the builtin "poor man's strace".
+ */
+
+#if DEBUG
+#define SYSCALL(fun, narg) #fun,
+static char *sfnames[] = {
+#include "syscalls.h"
+};
+#undef SYS
+#endif
+
+void system_call (struct pt_regs *regs)
+{
+	syscall_t syscall;
+	unsigned long parm0, parm1, parm2, parm3, parm4, parm5;
+	int nargs, res;
+	unsigned int syscallnr;
+	int ps;
+
+#if DEBUG
+	int i;
+	unsigned long parms[6];
+	char *sysname;
+#endif
+
+	regs->syscall = regs->areg[2];
+
+	do_syscall_trace();
+
+	/* Have to load after syscall_trace because strace
+	 * sometimes changes regs->syscall.
+	 */
+	syscallnr = regs->syscall;
+
+	parm0 = parm1 = parm2 = parm3 = parm4 = parm5 = 0;
+
+	/* Restore interrupt level to syscall invoker's.
+	 * If this were in assembly, we wouldn't disable
+	 * interrupts in the first place:
+	 */
+	local_save_flags (ps);
+	local_irq_restore((ps & ~XCHAL_PS_INTLEVEL_MASK) |
+			  (regs->ps & XCHAL_PS_INTLEVEL_MASK) );
+
+	if (syscallnr > __NR_Linux_syscalls) {
+		regs->areg[2] = -ENOSYS;
+		return;
+	}
+
+	syscall = sys_call_table[syscallnr];
+	nargs = sys_narg_table[syscallnr];
+
+	if (syscall == NULL) {
+		regs->areg[2] = -ENOSYS;
+		return;
+	}
+
+	/* There shouldn't be more than six arguments in the table! */
+
+	if (nargs > 6)
+		panic("Internal error - too many syscall arguments (%d)!\n",
+		      nargs);
+
+	/* Linux takes system-call arguments in registers.  The ABI
+         * and Xtensa software conventions require the system-call
+         * number in a2.  If an argument exists in a2, we move it to
+         * the next available register.  Note that for improved
+         * efficiency, we do NOT shift all parameters down one
+         * register to maintain the original order.
+	 *
+         * At best case (zero arguments), we just write the syscall
+         * number to a2.  At worst case (1 to 6 arguments), we move
+         * the argument in a2 to the next available register, then
+         * write the syscall number to a2.
+	 *
+         * For clarity, the following truth table enumerates all
+         * possibilities.
+	 *
+         * arguments	syscall number	arg0, arg1, arg2, arg3, arg4, arg5
+         * ---------	--------------	----------------------------------
+	 *	0	      a2
+	 *	1	      a2	a3
+	 *	2	      a2	a4,   a3
+	 *	3	      a2	a5,   a3,   a4
+	 *	4	      a2	a6,   a3,   a4,   a5
+	 *	5	      a2	a7,   a3,   a4,   a5,   a6
+	 *	6	      a2	a8,   a3,   a4,   a5,   a6,   a7
+	 */
+	if (nargs) {
+		parm0 = regs->areg[nargs+2];
+		parm1 = regs->areg[3];
+		parm2 = regs->areg[4];
+		parm3 = regs->areg[5];
+		parm4 = regs->areg[6];
+		parm5 = regs->areg[7];
+	} else /* nargs == 0 */
+		parm0 = (unsigned long) regs;
+
+#if DEBUG
+	parms[0] = parm0;
+	parms[1] = parm1;
+	parms[2] = parm2;
+	parms[3] = parm3;
+	parms[4] = parm4;
+	parms[5] = parm5;
+
+	sysname = sfnames[syscallnr];
+	if (strncmp(sysname, "sys_", 4) == 0)
+		sysname = sysname + 4;
+
+	printk("\017SYSCALL:I:%x:%d:%s  %s(", regs->pc, current->pid,
+	       current->comm, sysname);
+	for (i = 0; i < nargs; i++)
+		printk((i>0) ? ", %#lx" : "%#lx", parms[i]);
+	printk(")\n");
+#endif
+
+	res = syscall((void *)parm0, parm1, parm2, parm3, parm4, parm5);
+
+#if DEBUG
+	printk("\017SYSCALL:O:%d:%s  %s(",current->pid, current->comm, sysname);
+	for (i = 0; i < nargs; i++)
+		printk((i>0) ? ", %#lx" : "%#lx", parms[i]);
+	if (res < 4096)
+		printk(") = %d\n", res);
+	else
+		printk(") = %#x\n", res);
+#endif /* DEBUG */
+
+	regs->areg[2] = res;
+	do_syscall_trace();
+}
+
+/*
+ * sys_ipc() is the de-multiplexer for the SysV IPC calls..
+ *
+ * This is really horribly ugly.
+ */
+
+int sys_ipc (uint call, int first, int second,
+			int third, void __user *ptr, long fifth)
+{
+	int version, ret;
+
+	version = call >> 16; /* hack for backward compatibility */
+	call &= 0xffff;
+	ret = -ENOSYS;
+
+	switch (call) {
+	case SEMOP:
+		ret = sys_semtimedop (first, (struct sembuf __user *)ptr,
+				     second, NULL);
+		break;
+
+	case SEMTIMEDOP:
+		ret = sys_semtimedop (first, (struct sembuf __user *)ptr,
+				      second, (const struct timespec *) fifth);
+		break;
+
+	case SEMGET:
+		ret = sys_semget (first, second, third);
+		break;
+
+	case SEMCTL: {
+		union semun fourth;
+
+		if (ptr && !get_user(fourth.__pad, (void *__user *) ptr))
+			ret = sys_semctl (first, second, third, fourth);
+		break;
+		}
+
+	case MSGSND:
+		ret = sys_msgsnd (first, (struct msgbuf __user*) ptr,
+				  second, third);
+		break;
+
+	case MSGRCV:
+		switch (version) {
+		case 0: {
+			struct ipc_kludge tmp;
+
+			if (ptr && !copy_from_user(&tmp,
+					   (struct ipc_kludge *) ptr,
+					   sizeof (tmp)))
+				ret = sys_msgrcv (first, tmp.msgp, second,
+						  tmp.msgtyp, third);
+			break;
+			}
+
+		default:
+			ret = sys_msgrcv (first, (struct msgbuf __user *) ptr,
+					  second, 0, third);
+			break;
+		}
+		break;
+
+	case MSGGET:
+		ret = sys_msgget ((key_t) first, second);
+		break;
+
+	case MSGCTL:
+		ret = sys_msgctl (first, second, (struct msqid_ds __user*) ptr);
+		break;
+
+	case SHMAT: {
+		ulong raddr;
+		ret = do_shmat (first, (char __user *) ptr, second, &raddr);
+
+		if (!ret)
+			ret = put_user (raddr, (ulong __user *) third);
+
+		break;
+		}
+
+	case SHMDT:
+		ret = sys_shmdt ((char __user *)ptr);
+		break;
+
+	case SHMGET:
+		ret = sys_shmget (first, second, third);
+		break;
+
+	case SHMCTL:
+		ret = sys_shmctl (first, second, (struct shmid_ds __user*) ptr);
+		break;
+	}
+	return ret;
+}
+