1 | /* |
---|
2 | * cpu.c - This file contains implementation of C function to |
---|
3 | * Instanciate IDT entries. More detailled information can be found |
---|
4 | * on Intel site and more precisely in the following book : |
---|
5 | * |
---|
6 | * Pentium Processor familly |
---|
7 | * Developper's Manual |
---|
8 | * |
---|
9 | * Volume 3 : Architecture and Programming Manual |
---|
10 | * |
---|
11 | * Copyright (C) 1998 Eric Valette (valette@crf.canon.fr) |
---|
12 | * Canon Centre Recherche France. |
---|
13 | * |
---|
14 | * The license and distribution terms for this file may be |
---|
15 | * found in found in the file LICENSE in this distribution or at |
---|
16 | * http://www.OARcorp.com/rtems/license.html. |
---|
17 | * |
---|
18 | * $Id$ |
---|
19 | */ |
---|
20 | |
---|
21 | #include <libcpu/cpu.h> |
---|
22 | #include <irq.h> |
---|
23 | |
---|
24 | static rtems_raw_irq_connect_data* raw_irq_table; |
---|
25 | static rtems_raw_irq_connect_data default_raw_irq_entry; |
---|
26 | static interrupt_gate_descriptor default_idt_entry; |
---|
27 | static rtems_raw_irq_global_settings* local_settings; |
---|
28 | |
---|
29 | void create_interrupt_gate_descriptor (interrupt_gate_descriptor* idtEntry, |
---|
30 | rtems_raw_irq_hdl hdl) |
---|
31 | { |
---|
32 | idtEntry->low_offsets_bits = (((unsigned) hdl) & 0xffff); |
---|
33 | idtEntry->segment_selector = i386_get_cs(); |
---|
34 | idtEntry->fixed_value_bits = 0; |
---|
35 | idtEntry->gate_type = 0xe; |
---|
36 | idtEntry->privilege = 0; |
---|
37 | idtEntry->present = 1; |
---|
38 | idtEntry->high_offsets_bits = ((((unsigned) hdl) >> 16) & 0xffff); |
---|
39 | } |
---|
40 | |
---|
41 | rtems_raw_irq_hdl get_hdl_from_vector(rtems_vector_offset index) |
---|
42 | { |
---|
43 | rtems_raw_irq_hdl hdl; |
---|
44 | interrupt_gate_descriptor* idt_entry_tbl; |
---|
45 | unsigned limit; |
---|
46 | |
---|
47 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
---|
48 | |
---|
49 | /* Convert limit into number of entries */ |
---|
50 | limit = (limit + 1) >> 3; |
---|
51 | |
---|
52 | if(index >= limit) { |
---|
53 | return 0; |
---|
54 | } |
---|
55 | |
---|
56 | /* Convert limit into number of entries */ |
---|
57 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
---|
58 | |
---|
59 | if(index >= limit) { |
---|
60 | return 0; |
---|
61 | } |
---|
62 | |
---|
63 | * ((unsigned int*) &hdl) = (idt_entry_tbl[index].low_offsets_bits | |
---|
64 | (idt_entry_tbl[index].high_offsets_bits << 16)); |
---|
65 | return hdl; |
---|
66 | } |
---|
67 | |
---|
68 | int i386_set_idt_entry (const rtems_raw_irq_connect_data* irq) |
---|
69 | { |
---|
70 | interrupt_gate_descriptor* idt_entry_tbl; |
---|
71 | unsigned limit; |
---|
72 | unsigned int level; |
---|
73 | |
---|
74 | |
---|
75 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
---|
76 | |
---|
77 | /* Convert limit into number of entries */ |
---|
78 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
---|
79 | |
---|
80 | if (irq->idtIndex >= limit) { |
---|
81 | return 0; |
---|
82 | } |
---|
83 | /* |
---|
84 | * Check if default handler is actually connected. If not issue an error. |
---|
85 | * You must first get the current handler via i386_get_current_idt_entry |
---|
86 | * and then disconnect it using i386_delete_idt_entry. |
---|
87 | * RATIONALE : to always have the same transition by forcing the user |
---|
88 | * to get the previous handler before accepting to disconnect. |
---|
89 | */ |
---|
90 | if (get_hdl_from_vector(irq->idtIndex) != default_raw_irq_entry.hdl) { |
---|
91 | return 0; |
---|
92 | } |
---|
93 | |
---|
94 | _CPU_ISR_Disable(level); |
---|
95 | |
---|
96 | raw_irq_table [irq->idtIndex] = *irq; |
---|
97 | create_interrupt_gate_descriptor (&idt_entry_tbl[irq->idtIndex], irq->hdl); |
---|
98 | irq->on(irq); |
---|
99 | |
---|
100 | _CPU_ISR_Enable(level); |
---|
101 | return 1; |
---|
102 | } |
---|
103 | |
---|
104 | void _CPU_ISR_install_vector (unsigned vector, |
---|
105 | void* hdl, |
---|
106 | void** oldHdl) |
---|
107 | { |
---|
108 | interrupt_gate_descriptor* idt_entry_tbl; |
---|
109 | unsigned limit; |
---|
110 | interrupt_gate_descriptor new; |
---|
111 | unsigned int level; |
---|
112 | |
---|
113 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
---|
114 | |
---|
115 | /* Convert limit into number of entries */ |
---|
116 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
---|
117 | |
---|
118 | if (vector >= limit) { |
---|
119 | return; |
---|
120 | } |
---|
121 | _CPU_ISR_Disable(level) |
---|
122 | * ((unsigned int *) oldHdl) = idt_entry_tbl[vector].low_offsets_bits | |
---|
123 | (idt_entry_tbl[vector].high_offsets_bits << 16); |
---|
124 | |
---|
125 | create_interrupt_gate_descriptor(&new, hdl); |
---|
126 | idt_entry_tbl[vector] = new; |
---|
127 | |
---|
128 | _CPU_ISR_Enable(level); |
---|
129 | } |
---|
130 | |
---|
131 | int i386_get_current_idt_entry (rtems_raw_irq_connect_data* irq) |
---|
132 | { |
---|
133 | interrupt_gate_descriptor* idt_entry_tbl; |
---|
134 | unsigned limit; |
---|
135 | |
---|
136 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
---|
137 | |
---|
138 | /* Convert limit into number of entries */ |
---|
139 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
---|
140 | |
---|
141 | if (irq->idtIndex >= limit) { |
---|
142 | return 0; |
---|
143 | } |
---|
144 | raw_irq_table [irq->idtIndex].hdl = get_hdl_from_vector(irq->idtIndex); |
---|
145 | |
---|
146 | *irq = raw_irq_table [irq->idtIndex]; |
---|
147 | |
---|
148 | return 1; |
---|
149 | } |
---|
150 | |
---|
151 | int i386_delete_idt_entry (const rtems_raw_irq_connect_data* irq) |
---|
152 | { |
---|
153 | interrupt_gate_descriptor* idt_entry_tbl; |
---|
154 | unsigned limit; |
---|
155 | unsigned int level; |
---|
156 | |
---|
157 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
---|
158 | |
---|
159 | /* Convert limit into number of entries */ |
---|
160 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
---|
161 | |
---|
162 | if (irq->idtIndex >= limit) { |
---|
163 | return 0; |
---|
164 | } |
---|
165 | /* |
---|
166 | * Check if handler passed is actually connected. If not issue an error. |
---|
167 | * You must first get the current handler via i386_get_current_idt_entry |
---|
168 | * and then disconnect it using i386_delete_idt_entry. |
---|
169 | * RATIONALE : to always have the same transition by forcing the user |
---|
170 | * to get the previous handler before accepting to disconnect. |
---|
171 | */ |
---|
172 | if (get_hdl_from_vector(irq->idtIndex) != irq->hdl){ |
---|
173 | return 0; |
---|
174 | } |
---|
175 | _CPU_ISR_Disable(level); |
---|
176 | |
---|
177 | idt_entry_tbl[irq->idtIndex] = default_idt_entry; |
---|
178 | |
---|
179 | irq->off(irq); |
---|
180 | |
---|
181 | raw_irq_table[irq->idtIndex] = default_raw_irq_entry; |
---|
182 | raw_irq_table[irq->idtIndex].idtIndex = irq->idtIndex; |
---|
183 | |
---|
184 | _CPU_ISR_Enable(level); |
---|
185 | |
---|
186 | return 1; |
---|
187 | } |
---|
188 | |
---|
189 | /* |
---|
190 | * Caution this function assumes the IDTR has been already set. |
---|
191 | */ |
---|
192 | int i386_init_idt (rtems_raw_irq_global_settings* config) |
---|
193 | { |
---|
194 | unsigned limit; |
---|
195 | unsigned i; |
---|
196 | unsigned level; |
---|
197 | interrupt_gate_descriptor* idt_entry_tbl; |
---|
198 | |
---|
199 | i386_get_info_from_IDTR (&idt_entry_tbl, &limit); |
---|
200 | |
---|
201 | /* Convert limit into number of entries */ |
---|
202 | limit = (limit + 1) / sizeof(interrupt_gate_descriptor); |
---|
203 | |
---|
204 | if (config->idtSize != limit) { |
---|
205 | return 0; |
---|
206 | } |
---|
207 | /* |
---|
208 | * store various accelarators |
---|
209 | */ |
---|
210 | raw_irq_table = config->rawIrqHdlTbl; |
---|
211 | local_settings = config; |
---|
212 | default_raw_irq_entry = config->defaultRawEntry; |
---|
213 | |
---|
214 | _CPU_ISR_Disable(level); |
---|
215 | |
---|
216 | create_interrupt_gate_descriptor (&default_idt_entry, default_raw_irq_entry.hdl); |
---|
217 | |
---|
218 | for (i=0; i < limit; i++) { |
---|
219 | interrupt_gate_descriptor new; |
---|
220 | create_interrupt_gate_descriptor (&new, raw_irq_table[i].hdl); |
---|
221 | idt_entry_tbl[i] = new; |
---|
222 | if (raw_irq_table[i].hdl != default_raw_irq_entry.hdl) { |
---|
223 | raw_irq_table[i].on(&raw_irq_table[i]); |
---|
224 | } |
---|
225 | else { |
---|
226 | raw_irq_table[i].off(&raw_irq_table[i]); |
---|
227 | } |
---|
228 | } |
---|
229 | _CPU_ISR_Enable(level); |
---|
230 | |
---|
231 | return 1; |
---|
232 | } |
---|
233 | |
---|
234 | int i386_get_idt_config (rtems_raw_irq_global_settings** config) |
---|
235 | { |
---|
236 | *config = local_settings; |
---|
237 | return 1; |
---|
238 | } |
---|
239 | |
---|
240 | /* |
---|
241 | * Caution this function assumes the GDTR has been already set. |
---|
242 | */ |
---|
243 | int i386_set_gdt_entry (unsigned short segment_selector, unsigned base, |
---|
244 | unsigned limit) |
---|
245 | { |
---|
246 | unsigned gdt_limit; |
---|
247 | unsigned short tmp_segment = 0; |
---|
248 | unsigned int limit_adjusted; |
---|
249 | segment_descriptors* gdt_entry_tbl; |
---|
250 | |
---|
251 | |
---|
252 | i386_get_info_from_GDTR (&gdt_entry_tbl, &gdt_limit); |
---|
253 | |
---|
254 | if (segment_selector > limit) { |
---|
255 | return 0; |
---|
256 | } |
---|
257 | /* |
---|
258 | * set up limit first |
---|
259 | */ |
---|
260 | limit_adjusted = limit; |
---|
261 | if ( limit > 4095 ) { |
---|
262 | gdt_entry_tbl[segment_selector].granularity = 1; |
---|
263 | limit_adjusted /= 4096; |
---|
264 | } |
---|
265 | gdt_entry_tbl[segment_selector].limit_15_0 = limit_adjusted & 0xffff; |
---|
266 | gdt_entry_tbl[segment_selector].limit_19_16 = (limit_adjusted >> 16) & 0xf; |
---|
267 | /* |
---|
268 | * set up base |
---|
269 | */ |
---|
270 | gdt_entry_tbl[segment_selector].base_address_15_0 = base & 0xffff; |
---|
271 | gdt_entry_tbl[segment_selector].base_address_23_16 = (base >> 16) & 0xff; |
---|
272 | gdt_entry_tbl[segment_selector].base_address_31_24 = (base >> 24) & 0xff; |
---|
273 | /* |
---|
274 | * set up descriptor type (this may well becomes a parameter if needed) |
---|
275 | */ |
---|
276 | gdt_entry_tbl[segment_selector].type = 2; /* Data R/W */ |
---|
277 | gdt_entry_tbl[segment_selector].descriptor_type = 1; /* Code or Data */ |
---|
278 | gdt_entry_tbl[segment_selector].privilege = 0; /* ring 0 */ |
---|
279 | gdt_entry_tbl[segment_selector].present = 1; /* not present */ |
---|
280 | |
---|
281 | /* |
---|
282 | return 1; |
---|
283 | */ |
---|
284 | |
---|
285 | asm volatile( "movw %%ds,%0 ; movw %0,%%ds |
---|
286 | movw %%es,%0 ; movw %0,%%es |
---|
287 | movw %%fs,%0 ; movw %0,%%fs |
---|
288 | movw %%gs,%0 ; movw %0,%%gs |
---|
289 | movw %%ss,%0 ; movw %0,%%ss" |
---|
290 | : "=r" (tmp_segment) |
---|
291 | : "0" (tmp_segment) |
---|
292 | ); |
---|
293 | |
---|
294 | return 1; |
---|
295 | } |
---|