1 /**
2 * \file
3 * \brief Segment handling.
4 * \ingroup api_calls
5 */
6 /*
7 * (c) 2008-2009 Adam Lackorzynski <adam@os.inf.tu-dresden.de>
8 * economic rights: Technische Universität Dresden (Germany)
9 *
10 * This file is part of TUD:OS and distributed under the terms of the
11 * GNU General Public License 2.
12 * Please see the COPYING-GPL-2 file for details.
13 *
14 * As a special exception, you may use this file as part of a free software
15 * library without restriction. Specifically, if other files instantiate
16 * templates or use macros or inline functions from this file, or you compile
17 * this file and link it with other files to produce an executable, this
18 * file does not by itself cause the resulting executable to be covered by
19 * the GNU General Public License. This exception does not however
20 * invalidate any other reasons why the executable file might be covered by
21 * the GNU General Public License.
22 */
23 /*****************************************************************************/
24 #ifndef __L4_SYS__ARCH_X86__SEGMENT_H__
25 #define __L4_SYS__ARCH_X86__SEGMENT_H__
26
27 #ifndef L4API_l4f
28 #error This header file can only be used with a L4API version!
29 #endif
30
31 #include <l4/sys/ipc.h>
32
33 /**
34 * Set LDT segments descriptors.
35 * \ingroup api_calls_fiasco
36 *
37 * \param task Task to set the segment for.
38 * \param ldt Pointer to LDT hardware descriptors.
39 * \param num_desc Number of descriptors.
40 * \param entry_number_start Entry number to start.
41 * \param utcb UTCB of the caller.
42 */
43 L4_INLINE long
44 fiasco_ldt_set(l4_cap_idx_t task, void *ldt, unsigned int size,
45 unsigned int entry_number_start, l4_utcb_t *utcb);
46
47 /**
48 * Set GDT segment descriptors. Fiasco supports 3 consecutive entries,
49 * starting at the value returned by fiasco_gdt_get_entry_offset()
50 * \ingroup api_calls_fiasco
51 *
52 * \param thread Thread to set the GDT entry for.
53 * \param desc Pointer to GDT descriptors.
54 * \param size Size of the descriptors in bytes
55 * (multiple of 8).
56 * \param entry_number_start Entry number to start (valid values: 0-2).
57 * \param utcb UTCB of the caller.
58 * \return System call error
59 */
60 L4_INLINE long
61 fiasco_gdt_set(l4_cap_idx_t thread, void *desc, unsigned int size,
62 unsigned int entry_number_start, l4_utcb_t *utcb);
63
64 /**
65 * Return the offset of the entry in the GDT.
66 * \param thread Thread to get info from.
67 * \param utcb UTCB of the caller.
68 * \ingroup api_calls_fiasco
69 */
70 L4_INLINE unsigned
71 fiasco_gdt_get_entry_offset(l4_cap_idx_t thread, l4_utcb_t *utcb);
72
73 /**
74 * \brief Contants for LDT handling.
75 */
76 enum L4_task_ldt_x86_consts
77 {
78 /** Size of an LDT entry. */
79 L4_TASK_LDT_X86_ENTRY_SIZE = 8,
80 /** Maximum number of LDT entries that can be written with one call. */
81 L4_TASK_LDT_X86_MAX_ENTRIES
82 = (L4_UTCB_GENERIC_DATA_SIZE - 2)
83 / (L4_TASK_LDT_X86_ENTRY_SIZE / (L4_MWORD_BITS / 8)),
84 };
85
86 /*****************************************************************************
87 *** Implementation
88 *****************************************************************************/
89
90 #include <l4/sys/task.h>
91 #include <l4/sys/thread.h>
92
93 L4_INLINE long
fiasco_ldt_set(l4_cap_idx_t task,void * ldt,unsigned int num_desc,unsigned int entry_number_start,l4_utcb_t * utcb)94 fiasco_ldt_set(l4_cap_idx_t task, void *ldt, unsigned int num_desc,
95 unsigned int entry_number_start, l4_utcb_t *utcb)
96 {
97 if (num_desc > L4_TASK_LDT_X86_MAX_ENTRIES)
98 return -L4_EINVAL;
99 l4_utcb_mr_u(utcb)->mr[0] = L4_TASK_LDT_SET_X86_OP;
100 l4_utcb_mr_u(utcb)->mr[1] = entry_number_start;
101 __builtin_memcpy(&l4_utcb_mr_u(utcb)->mr[2], ldt,
102 num_desc * L4_TASK_LDT_X86_ENTRY_SIZE);
103 return l4_error_u(l4_ipc_call(task, utcb, l4_msgtag(L4_PROTO_TASK, 2 + num_desc * 2, 0, 0), L4_IPC_NEVER), utcb);
104 }
105
106 L4_INLINE unsigned
fiasco_gdt_get_entry_offset(l4_cap_idx_t thread,l4_utcb_t * utcb)107 fiasco_gdt_get_entry_offset(l4_cap_idx_t thread, l4_utcb_t *utcb)
108 {
109 l4_utcb_mr_u(utcb)->mr[0] = L4_THREAD_X86_GDT_OP;
110 if (l4_error_u(l4_ipc_call(thread, utcb, l4_msgtag(L4_PROTO_THREAD, 1, 0, 0), L4_IPC_NEVER), utcb))
111 return -1;
112 return l4_utcb_mr_u(utcb)->mr[0];
113 }
114
115 #endif /* ! __L4_SYS__ARCH_X86__SEGMENT_H__ */
116