xref: /linux/arch/xtensa/kernel/syscall.c (revision 320fefa9e2edc67011e235ea1d50f0d00ddfe004)
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 <linux/linkage.h>
21 #include <linux/stringify.h>
22 #include <linux/errno.h>
23 #include <linux/syscalls.h>
24 #include <linux/file.h>
25 #include <linux/fs.h>
26 #include <linux/mman.h>
27 #include <linux/sched/mm.h>
28 #include <linux/shm.h>
29 
30 syscall_t sys_call_table[] /* FIXME __cacheline_aligned */= {
31 #define __SYSCALL(nr, entry)	(syscall_t)entry,
32 #include <asm/syscall_table.h>
33 };
34 
35 #define COLOUR_ALIGN(addr, pgoff) \
36 	((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \
37 	 (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
38 
39 asmlinkage long xtensa_shmat(int shmid, char __user *shmaddr, int shmflg)
40 {
41 	unsigned long ret;
42 	long err;
43 
44 	err = do_shmat(shmid, shmaddr, shmflg, &ret, SHMLBA);
45 	if (err)
46 		return err;
47 	return (long)ret;
48 }
49 
50 asmlinkage long xtensa_fadvise64_64(int fd, int advice,
51 		unsigned long long offset, unsigned long long len)
52 {
53 	return ksys_fadvise64_64(fd, offset, len, advice);
54 }
55 
56 #ifdef CONFIG_MMU
57 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
58 		unsigned long len, unsigned long pgoff, unsigned long flags)
59 {
60 	struct vm_area_struct *vmm;
61 	struct vma_iterator vmi;
62 
63 	if (flags & MAP_FIXED) {
64 		/* We do not accept a shared mapping if it would violate
65 		 * cache aliasing constraints.
66 		 */
67 		if ((flags & MAP_SHARED) &&
68 				((addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)))
69 			return -EINVAL;
70 		return addr;
71 	}
72 
73 	if (len > TASK_SIZE)
74 		return -ENOMEM;
75 	if (!addr)
76 		addr = TASK_UNMAPPED_BASE;
77 
78 	if (flags & MAP_SHARED)
79 		addr = COLOUR_ALIGN(addr, pgoff);
80 	else
81 		addr = PAGE_ALIGN(addr);
82 
83 	vma_iter_init(&vmi, current->mm, addr);
84 	for_each_vma(vmi, vmm) {
85 		/* At this point:  (addr < vmm->vm_end). */
86 		if (addr + len <= vm_start_gap(vmm))
87 			break;
88 
89 		addr = vmm->vm_end;
90 		if (flags & MAP_SHARED)
91 			addr = COLOUR_ALIGN(addr, pgoff);
92 	}
93 
94 	if (TASK_SIZE - len < addr)
95 		return -ENOMEM;
96 
97 	return addr;
98 }
99 #endif
100