xref: /openbmc/linux/arch/xtensa/kernel/syscall.c (revision be709d48)
1 /*
2  * arch/xtensa/kernel/syscall.c
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file "COPYING" in the main directory of this archive
6  * for more details.
7  *
8  * Copyright (C) 2001 - 2005 Tensilica Inc.
9  * Copyright (C) 2000 Silicon Graphics, Inc.
10  * Copyright (C) 1995 - 2000 by Ralf Baechle
11  *
12  * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
13  * Marc Gauthier <marc@tensilica.com, marc@alumni.uwaterloo.ca>
14  * Chris Zankel <chris@zankel.net>
15  * Kevin Chea
16  *
17  */
18 #include <linux/uaccess.h>
19 #include <asm/syscall.h>
20 #include <asm/unistd.h>
21 #include <linux/linkage.h>
22 #include <linux/stringify.h>
23 #include <linux/errno.h>
24 #include <linux/syscalls.h>
25 #include <linux/file.h>
26 #include <linux/fs.h>
27 #include <linux/mman.h>
28 #include <linux/sched/mm.h>
29 #include <linux/shm.h>
30 
31 syscall_t sys_call_table[__NR_syscalls] /* FIXME __cacheline_aligned */= {
32 	[0 ... __NR_syscalls - 1] = (syscall_t)&sys_ni_syscall,
33 
34 #define __SYSCALL(nr, entry, nargs)[nr] = (syscall_t)entry,
35 #include <asm/syscall_table.h>
36 #undef __SYSCALL
37 };
38 
39 #define COLOUR_ALIGN(addr, pgoff) \
40 	((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \
41 	 (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
42 
43 asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
44 {
45 	unsigned long ret;
46 	long err;
47 
48 	err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
49 	if (err)
50 		return err;
51 	return (long)ret;
52 }
53 
54 asmlinkage long xtensa_fadvise64_64(int fd, int advice,
55 		unsigned long long offset, unsigned long long len)
56 {
57 	return ksys_fadvise64_64(fd, offset, len, advice);
58 }
59 
60 #ifdef CONFIG_MMU
61 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
62 		unsigned long len, unsigned long pgoff, unsigned long flags)
63 {
64 	struct vm_area_struct *vmm;
65 
66 	if (flags & MAP_FIXED) {
67 		/* We do not accept a shared mapping if it would violate
68 		 * cache aliasing constraints.
69 		 */
70 		if ((flags & MAP_SHARED) &&
71 				((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
72 			return -EINVAL;
73 		return addr;
74 	}
75 
76 	if (len > TASK_SIZE)
77 		return -ENOMEM;
78 	if (!addr)
79 		addr = TASK_UNMAPPED_BASE;
80 
81 	if (flags & MAP_SHARED)
82 		addr = COLOUR_ALIGN(addr, pgoff);
83 	else
84 		addr = PAGE_ALIGN(addr);
85 
86 	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
87 		/* At this point:  (!vmm || addr < vmm->vm_end). */
88 		if (TASK_SIZE - len < addr)
89 			return -ENOMEM;
90 		if (!vmm || addr + len <= vm_start_gap(vmm))
91 			return addr;
92 		addr = vmm->vm_end;
93 		if (flags & MAP_SHARED)
94 			addr = COLOUR_ALIGN(addr, pgoff);
95 	}
96 }
97 #endif
98