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source: trunk/hal/tsar_mips32/core/hal_exception.c @ 633

Last change on this file since 633 was 632, checked in by alain, 5 years ago
This version replace the RPC by direct remote memory access for physical pages allacation/release. It is commited before being tested.
File size: 20.0 KB

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1	/*
2	* hal_exception.c - implementation of exception handler for TSAR-MIPS32.
3	*
4	* Author Alain Greiner (2016, 2017)
5	*
6	* Copyright (c) UPMC Sorbonne Universites
7	*
8	* This file is part of ALMOS-MKH.
9	*
10	* ALMOS-MKH is free software; you can redistribute it and/or modify it
11	* under the terms of the GNU General Public License as published by
12	* the Free Software Foundation; version 2.0 of the License.
13	*
14	* ALMOS-MKH is distributed in the hope that it will be useful, but
15	* WITHOUT ANY WARRANTY; without even the implied warranty of
16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17	* General Public License for more details.
18	*
19	* You should have received a copy of the GNU General Public License
20	* along with ALMOS-MKH; if not, write to the Free Software Foundation,
21	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22	*/
23
24	#include <hal_kernel_types.h>
25	#include <hal_irqmask.h>
26	#include <hal_special.h>
27	#include <hal_exception.h>
28	#include <thread.h>
29	#include <printk.h>
30	#include <chdev.h>
31	#include <vmm.h>
32	#include <errno.h>
33	#include <scheduler.h>
34	#include <core.h>
35	#include <syscalls.h>
36	#include <shared_syscalls.h>
37	#include <remote_busylock.h>
38	#include <hal_kentry.h>
39	#include <hal_exception.h>
40
41	//////////////////////////////////////////////////////////////////////////////////////////
42	// Extern global variables
43	//////////////////////////////////////////////////////////////////////////////////////////
44
45	extern chdev_directory_t chdev_dir; // allocated in the kernel_init.c file.
46
47	//////////////////////////////////////////////////////////////////////////////////////////
48	// This enum defines the mask values for an MMU exception code reported by the mips32.
49	//////////////////////////////////////////////////////////////////////////////////////////
50
51	typedef enum
52	{
53	MMU_WRITE_PT1_UNMAPPED = 0x0001,
54	MMU_WRITE_PT2_UNMAPPED = 0x0002,
55	MMU_WRITE_PRIVILEGE_VIOLATION = 0x0004,
56	MMU_WRITE_ACCESS_VIOLATION = 0x0008,
57	MMU_WRITE_UNDEFINED_XTN = 0x0020,
58	MMU_WRITE_PT1_ILLEGAL_ACCESS = 0x0040,
59	MMU_WRITE_PT2_ILLEGAL_ACCESS = 0x0080,
60	MMU_WRITE_DATA_ILLEGAL_ACCESS = 0x0100,
61
62	MMU_READ_PT1_UNMAPPED = 0x1001,
63	MMU_READ_PT2_UNMAPPED = 0x1002,
64	MMU_READ_PRIVILEGE_VIOLATION = 0x1004,
65	MMU_READ_EXEC_VIOLATION = 0x1010,
66	MMU_READ_UNDEFINED_XTN = 0x1020,
67	MMU_READ_PT1_ILLEGAL_ACCESS = 0x1040,
68	MMU_READ_PT2_ILLEGAL_ACCESS = 0x1080,
69	MMU_READ_DATA_ILLEGAL_ACCESS = 0x1100,
70	}
71	mmu_exception_subtype_t;
72
73	//////////////////////////////////////////////////////////////////////////////////////////
74	// This enum defines the relevant values for XCODE field in mips32 CP0_CR register.
75	//////////////////////////////////////////////////////////////////////////////////////////
76
77	typedef enum
78	{
79	XCODE_ADEL = 0x4, // Illegal address for data load
80	XCODE_ADES = 0x5, // Illegal address for data store
81	XCODE_IBE = 0x6, // Instruction MMU exception (can be NON-FATAL)
82	XCODE_DBE = 0x7, // Data MMU exception (can be NON-FATAL)
83	XCODE_RI = 0xA, // Reserved instruction exception
84	XCODE_CPU = 0xB, // Coprocessor unusable exception (can be NON-FATAl)
85	XCODE_OVR = 0xC, // Arithmetic Overflow exception
86	}
87	xcode_values_t;
88
89	/////////////////////////////////////////////
90	char * hal_mmu_exception_str( uint32_t code )
91	{
92	switch (code) {
93	case (MMU_WRITE_PT1_UNMAPPED): return "WRITE_PT1_UNMAPPED";
94	case (MMU_WRITE_PT2_UNMAPPED): return "WRITE_PT2_UNMAPPED";
95	case (MMU_WRITE_PRIVILEGE_VIOLATION): return "WRITE_PRIVILEGE_VIOLATION";
96	case (MMU_WRITE_ACCESS_VIOLATION): return "WRITE_ACCESS_VIOLATION";
97	case (MMU_WRITE_UNDEFINED_XTN): return "WRITE_UNDEFINED_XTN";
98	case (MMU_WRITE_PT1_ILLEGAL_ACCESS): return "WRITE_PT1_ILLEGAL_ACCESS";
99	case (MMU_WRITE_PT2_ILLEGAL_ACCESS): return "WRITE_PT2_ILLEGAL_ACCESS";
100	case (MMU_WRITE_DATA_ILLEGAL_ACCESS): return "WRITE_DATA_ILLEGAL_ACCESS";
101	case (MMU_READ_PT1_UNMAPPED): return "READ_PT1_UNMAPPED";
102	case (MMU_READ_PT2_UNMAPPED): return "READ_PT2_UNMAPPED";
103	case (MMU_READ_PRIVILEGE_VIOLATION): return "READ_PRIVILEGE_VIOLATION";
104	case (MMU_READ_EXEC_VIOLATION): return "READ_EXEC_VIOLATION";
105	case (MMU_READ_UNDEFINED_XTN): return "READ_UNDEFINED_XTN";
106	case (MMU_READ_PT1_ILLEGAL_ACCESS): return "READ_PT1_ILLEGAL_ACCESS";
107	case (MMU_READ_PT2_ILLEGAL_ACCESS): return "READ_PT2_ILLEGAL_ACCESS";
108	case (MMU_READ_DATA_ILLEGAL_ACCESS): return "READ_DATA_ILLEGAL_ACCESS";
109	default: return "undefined";
110	}
111	}
112
113	//////////////////////////////////////////////////////////////////////////////////////////
114	// This function is called when a FPU Coprocessor Unavailable exception has been
115	// detected for the calling thread.
116	// It enables the FPU, It saves the current FPU context in the current owner thread
117	// descriptor if required, and restore the FPU context from the calling thread descriptor.
118	//////////////////////////////////////////////////////////////////////////////////////////
119	// @ this : pointer on faulty thread descriptor.
120	// @ return always EXCP_NON_FATAL
121	//////////////////////////////////////////////////////////////////////////////////////////
122	error_t hal_fpu_exception( thread_t * this )
123	{
124	core_t * core = this->core;
125
126	// enable FPU (in core SR)
127	hal_fpu_enable();
128
129	// save FPU register values in current owner thread if required
130	if( core->fpu_owner != NULL )
131	{
132	if( core->fpu_owner != this )
133	{
134	// save the FPU registers to current owner thread context
135	hal_fpu_context_save( XPTR( local_cxy , core->fpu_owner ) );
136
137	// restore FPU registers from requesting thread context
138	hal_fpu_context_restore( this );
139
140	// attach the FPU to the requesting thread
141	core->fpu_owner = this;
142	}
143	}
144	else
145	{
146	// restore FPU registers from requesting thread context
147	hal_fpu_context_restore( this );
148
149	// attach the FPU to the requesting thread
150	core->fpu_owner = this;
151	}
152
153	return EXCP_NON_FATAL;
154
155	} // end hal_fpu_exception()
156
157	//////////////////////////////////////////////////////////////////////////////////////////
158	// This function is called when an MMU exception has been detected (IBE / DBE).
159	// It get the relevant exception arguments from the MMU.
160	// It signal a fatal error in case of illegal access. In case of page unmapped,
161	// it get the client process to access the relevant VMM: for a RPC thread, the client
162	// process is NOT the calling thread process.
163	// Then, it checks that the faulty address belongs to a registered vseg, update the local
164	// vseg list from the reference cluster if required, and signal a fatal user error
165	// in case of illegal virtual address. Finally, it updates the local page table from the
166	// reference cluster.
167	// WARNING : In order to prevent deadlocks, this function enable IRQs before calling the
168	// vmm_handle_page_fault() and the vmm_handle_cow() functions, because concurrent calls
169	// to these functions can create cross dependencies...
170	//////////////////////////////////////////////////////////////////////////////////////////
171	// @ this : pointer on faulty thread descriptor.
172	// @ excPC :
173	// @ is_ins : IBE if true / DBE if false.
174	// @ return EXCP_NON_FATAL / EXCP_USER_ERROR / EXCP_KERNEL_PANIC
175	//////////////////////////////////////////////////////////////////////////////////////////
176	error_t hal_mmu_exception( thread_t * this,
177	uint32_t excPC,
178	bool_t is_ins )
179	{
180	process_t * process;
181	error_t error;
182
183	uint32_t mmu_ins_excp_code;
184	uint32_t mmu_ins_bad_vaddr;
185	uint32_t mmu_dat_excp_code;
186	uint32_t mmu_dat_bad_vaddr;
187
188	uint32_t bad_vaddr;
189	uint32_t excp_code;
190
191	// check thread type
192	if( CURRENT_THREAD->type != THREAD_USER )
193	{
194	printk("\n[PANIC] in %s : illegal thread type %s\n",
195	__FUNCTION__, thread_type_str(CURRENT_THREAD->type) );
196
197	return EXCP_KERNEL_PANIC;
198	}
199
200	// get faulty thread process
201	process = this->process;
202
203	// get relevant values from MMU
204	hal_get_mmu_excp( &mmu_ins_excp_code,
205	&mmu_ins_bad_vaddr,
206	&mmu_dat_excp_code,
207	&mmu_dat_bad_vaddr );
208
209	// get exception code and faulty vaddr, depending on IBE/DBE
210	if( is_ins )
211	{
212	excp_code = mmu_ins_excp_code;
213	bad_vaddr = mmu_ins_bad_vaddr;
214	}
215	else
216	{
217	excp_code = mmu_dat_excp_code;
218	bad_vaddr = mmu_dat_bad_vaddr;
219	}
220
221	#if DEBUG_HAL_EXCEPTIONS
222	uint32_t cycle = (uint32_t)hal_get_cycles();
223	if( DEBUG_HAL_EXCEPTIONS < cycle )
224	printk("\n[%s] thread[%x,%x] on core [%x,%x] enter\n is_ins %d / %s / vaddr %x / cycle %d\n",
225	__FUNCTION__, process->pid, this->trdid, local_cxy, this->core->lid,
226	is_ins, hal_mmu_exception_str(excp_code), bad_vaddr, cycle);
227	#endif
228
229	// analyse exception code
230	switch( excp_code )
231	{
232	case MMU_WRITE_PT1_UNMAPPED: // can be non fatal
233	case MMU_WRITE_PT2_UNMAPPED: // can be non fatal
234	case MMU_READ_PT1_UNMAPPED: // can be non fatal
235	case MMU_READ_PT2_UNMAPPED: // can be non fatal
236	{
237	// try to map the unmapped PTE
238	error = vmm_handle_page_fault( process,
239	bad_vaddr >> CONFIG_PPM_PAGE_SHIFT );
240
241	if( error == EXCP_NON_FATAL ) // page-fault successfully handled
242	{
243
244	#if DEBUG_HAL_EXCEPTIONS
245	cycle = (uint32_t)hal_get_cycles();
246	if( DEBUG_HAL_EXCEPTIONS < cycle )
247	printk("\n[%s] thread[%x,%x] on core [%x,%x] exit\n page-fault handled for vaddr = %x\n",
248	__FUNCTION__, process->pid, this->trdid, local_cxy, this->core->lid, bad_vaddr );
249	#endif
250
251	return EXCP_NON_FATAL;
252	}
253	else if( error == EXCP_USER_ERROR ) // illegal vaddr
254	{
255	printk("\n[ERROR] in %s : thread[%x,%x] on core[%x,%x] / cycle %d\n"
256	" %s : epc %x / badvaddr %x / is_ins %d\n",
257	__FUNCTION__, this->process->pid, this->trdid, local_cxy,
258	this->core->lid, (uint32_t)hal_get_cycles(),
259	hal_mmu_exception_str(excp_code), excPC, bad_vaddr, is_ins );
260
261	return EXCP_USER_ERROR;
262	}
263	else // error == EXCP_KERNEL_PANIC
264	{
265	printk("\n[PANIC] in %s : thread[%x,%x] on core[%x,%x] / cycle %d\n"
266	" %s : epc %x / badvaddr %x / is_ins %d\n",
267	__FUNCTION__, this->process->pid, this->trdid, local_cxy,
268	this->core->lid, (uint32_t)hal_get_cycles(),
269	hal_mmu_exception_str(excp_code), excPC, bad_vaddr, is_ins );
270
271	return EXCP_KERNEL_PANIC;
272	}
273	}
274	case MMU_WRITE_PRIVILEGE_VIOLATION: // illegal user error
275	case MMU_READ_PRIVILEGE_VIOLATION: // illegal
276	{
277	printk("\n[ERROR] in %s : thread[%x,%x] on core[%x,%x] / cycle %d\n"
278	" %s : epc %x / badvaddr %x / is_ins %d\n",
279	__FUNCTION__, this->process->pid, this->trdid, local_cxy,
280	this->core->lid, (uint32_t)hal_get_cycles(),
281	hal_mmu_exception_str(excp_code), excPC, bad_vaddr, is_ins );
282
283	return EXCP_USER_ERROR;
284	}
285	case MMU_WRITE_ACCESS_VIOLATION: // can be non fatal if COW
286	{
287	// try to handle a possible COW
288	error = vmm_handle_cow( process,
289	bad_vaddr >> CONFIG_PPM_PAGE_SHIFT );
290
291	if( error == EXCP_NON_FATAL ) // COW successfully handled
292	{
293
294	#if DEBUG_HAL_EXCEPTIONS
295	cycle = (uint32_t)hal_get_cycles();
296	if( DEBUG_HAL_EXCEPTIONS < cycle )
297	printk("\n[%s] thread[%x,%x] exit / copy-on-write handled for vaddr = %x\n",
298	__FUNCTION__, process->pid, this->trdid, bad_vaddr );
299	#endif
300	return EXCP_NON_FATAL;
301	}
302	else if( error == EXCP_USER_ERROR ) // illegal write access
303	{
304	printk("\n[ERROR] in %s : thread[%x,%x] on core[%x,%x] / cycle %d\n"
305	" %s : epc %x / badvaddr %x / is_ins %d\n",
306	__FUNCTION__, this->process->pid, this->trdid, local_cxy,
307	this->core->lid, (uint32_t)hal_get_cycles(),
308	hal_mmu_exception_str(excp_code), excPC, bad_vaddr, is_ins );
309
310	return EXCP_USER_ERROR;
311	}
312	else // error == EXCP_KERNEL_PANIC
313	{
314	printk("\n[PANIC] in %s : thread[%x,%x] on core[%x,%x] / cycle %d\n"
315	" %s : epc %x / badvaddr %x / is_ins %d\n",
316	__FUNCTION__, this->process->pid, this->trdid, local_cxy,
317	this->core->lid, (uint32_t)hal_get_cycles(),
318	hal_mmu_exception_str(excp_code), excPC, bad_vaddr, is_ins );
319
320	return EXCP_USER_ERROR;
321	}
322	}
323	case MMU_READ_EXEC_VIOLATION: // user error
324	{
325	printk("\n[ERROR] in %s : thread[%x,%x] on core[%x,%x] / cycle %d\n"
326	" %s : epc %x / badvaddr %x / is_ins %d\n",
327	__FUNCTION__, this->process->pid, this->trdid, local_cxy,
328	this->core->lid, (uint32_t)hal_get_cycles(),
329	hal_mmu_exception_str(excp_code), excPC, bad_vaddr, is_ins );
330
331	return EXCP_USER_ERROR;
332	}
333	default: // this is a kernel error
334	{
335	printk("\n[PANIC] in %s : thread[%x,%x] on core[%x,%x] / cycle %d\n"
336	" %s : epc %x / badvaddr %x / is_ins %d\n",
337	__FUNCTION__, this->process->pid, this->trdid, local_cxy,
338	this->core->lid, (uint32_t)hal_get_cycles(),
339	hal_mmu_exception_str(excp_code), excPC, bad_vaddr, is_ins );
340
341	return EXCP_KERNEL_PANIC;
342	}
343	}
344	} // end hal_mmu_exception()
345
346	//////////////////////////////////////////////////////////////////////////////////////////
347	// This function prints on the kernel terminal the saved context (core registers)
348	// and the thread state of a faulty thread.
349	//////////////////////////////////////////////////////////////////////////////////////////
350	// @ this : pointer on faulty thread descriptor.
351	//////////////////////////////////////////////////////////////////////////////////////////
352	static void hal_exception_dump( thread_t * this )
353	{
354	core_t * core = this->core;
355	process_t * process = this->process;
356	reg_t * uzone = this->uzone_current;
357
358	// get pointers on TXT0 chdev
359	xptr_t txt0_xp = chdev_dir.txt_tx[0];
360	cxy_t txt0_cxy = GET_CXY( txt0_xp );
361	chdev_t * txt0_ptr = GET_PTR( txt0_xp );
362
363	// get extended pointer on remote TXT0 chdev lock
364	xptr_t lock_xp = XPTR( txt0_cxy , &txt0_ptr->wait_lock );
365
366	// get TXT0 lock in busy waiting mode
367	remote_busylock_acquire( lock_xp );
368
369	nolock_printk("\n=== thread(%x,%x) / core[%d] / cycle %d ===\n",
370	process->pid, this->trdid, core->lid, (uint32_t)hal_get_cycles() );
371
372	nolock_printk("busylocks = %d / blocked_vector = %X / flags = %X\n\n",
373	this->busylocks, this->blocked, this->flags );
374
375	nolock_printk("c0_cr %X c0_epc %X c0_sr %X c0_th %X\n",
376	uzone[UZ_CR], uzone[UZ_EPC], uzone[UZ_SR], uzone[UZ_TH] );
377
378	nolock_printk("c2_mode %X c2_ptpr %X\n",
379	uzone[UZ_MODE], uzone[UZ_PTPR] );
380
381	nolock_printk("at_01 %X v0_2 %X v1_3 %X a0_4 %X a1_5 %X\n",
382	uzone[UZ_AT], uzone[UZ_V0], uzone[UZ_V1], uzone[UZ_A0], uzone[UZ_A1] );
383
384	nolock_printk("a2_6 %X a3_7 %X t0_8 %X t1_9 %X t2_10 %X\n",
385	uzone[UZ_A2], uzone[UZ_A3], uzone[UZ_T0], uzone[UZ_T1], uzone[UZ_T2] );
386
387	nolock_printk("t3_11 %X t4_12 %X t5_13 %X t6_14 %X t7_15 %X\n",
388	uzone[UZ_T3], uzone[UZ_T4], uzone[UZ_T5], uzone[UZ_T6], uzone[UZ_T7] );
389
390	nolock_printk("s0_16 %X s1_17 %X s2_18 %X s3_19 %X s4_20 %X\n",
391	uzone[UZ_S0], uzone[UZ_S1], uzone[UZ_S2], uzone[UZ_S3], uzone[UZ_S4] );
392
393	nolock_printk("s5_21 %X s6_22 %X s7_23 %X t8_24 %X t9_25 %X\n",
394	uzone[UZ_S5], uzone[UZ_S6], uzone[UZ_S7], uzone[UZ_T8], uzone[UZ_T9] );
395
396	nolock_printk("gp_28 %X sp_29 %X S8_30 %X ra_31 %X\n",
397	uzone[UZ_GP], uzone[UZ_SP], uzone[UZ_S8], uzone[UZ_RA] );
398
399	// release the lock
400	remote_busylock_release( lock_xp );
401
402	} // end hal_exception_dump()
403
404	/////////////////////////////
405	void hal_do_exception( void )
406	{
407	uint32_t * uzone;
408	thread_t * this;
409	error_t error;
410	uint32_t excCode; // 4 bits XCODE from CP0_CR
411	uint32_t excPC; // fauty instruction address
412
413	// get pointer on faulty thread uzone
414	this = CURRENT_THREAD;
415	uzone = (uint32_t *)CURRENT_THREAD->uzone_current;
416
417	// get XCODE and EPC from UZONE
418	excCode = (uzone[UZ_CR] >> 2) & 0xF;
419	excPC = uzone[UZ_EPC];
420
421	#if DEBUG_HAL_EXCEPTIONS
422	uint32_t cycle = (uint32_t)hal_get_cycles();
423	if( DEBUG_HAL_EXCEPTIONS < cycle )
424	printk("\n[%s] thread[%x,%x] enter / core[%x,%d] / epc %x / xcode %x / cycle %d\n",
425	__FUNCTION__, this->process->pid, this->trdid,
426	local_cxy, this->core->lid, excPC, excCode, cycle );
427	#endif
428
429	switch(excCode)
430	{
431	case XCODE_DBE: // Data Bus Error : can be non fatal if page fault
432	{
433	error = hal_mmu_exception( this , excPC , false ); // data MMU exception
434	break;
435	}
436	case XCODE_IBE: // Instruction Bus Error : can be non fatal if page fault
437	{
438	error = hal_mmu_exception( this , excPC , true ); // ins MMU exception
439	break;
440	}
441	case XCODE_CPU: // Coprocessor unavailable : can be non fatal if FPU
442	{
443	if( ((uzone[UZ_CR] >> 28) & 0x3) == 1 ) // FPU
444	{
445	error = hal_fpu_exception( this );
446	}
447	else // undefined coprocessor
448	{
449	printk("\n[USER_ERROR] in %s for thread[%x,%x]\n"
450	" undefined coprocessor / epc %x\n",
451	__FUNCTION__, this->process->pid, this->trdid, excPC );
452
453	error = EXCP_USER_ERROR;
454	}
455	break;
456	}
457	case XCODE_OVR: // Arithmetic Overflow : user fatal error
458	{
459	printk("\n[USER_ERROR] in %s for thread[%x,%x]\n"
460	" arithmetic overflow / epc %x\n",
461	__FUNCTION__, this->process->pid, this->trdid, excPC );
462
463	error = EXCP_USER_ERROR;
464	break;
465	}
466	case XCODE_RI: // Reserved Instruction : user fatal error
467	{
468	printk("\n[USER_ERROR] in %s for thread[%x,%x]\n"
469	" reserved instruction / epc %x\n",
470	__FUNCTION__, this->process->pid, this->trdid, excPC );
471
472	error = EXCP_USER_ERROR;
473	break;
474	}
475	case XCODE_ADEL: // user fatal error
476	{
477	printk("\n[USER_ERROR] in %s for thread[%x,%x]\n"
478	" illegal data load address / epc %x / bad_address %x\n",
479	__FUNCTION__, this->process->pid, this->trdid, excPC, hal_get_bad_vaddr() );
480
481	error = EXCP_USER_ERROR;
482	break;
483	}
484	case XCODE_ADES: // user fatal error
485	{
486	printk("\n[USER_ERROR] in %s for thread[%x,%x]\n"
487	" illegal data store address / epc %x / bad_address %x\n",
488	__FUNCTION__, this->process->pid, this->trdid, excPC, hal_get_bad_vaddr() );
489
490	error = EXCP_USER_ERROR;
491	break;
492	}
493	default:
494	{
495	error = EXCP_KERNEL_PANIC;
496	}
497	}
498
499	// analyse error code
500	if( error == EXCP_USER_ERROR ) // user error => kill user process
501	{
502	hal_exception_dump( this );
503
504	sys_exit( EXIT_FAILURE );
505	}
506	else if( error == EXCP_KERNEL_PANIC ) // kernel error => kernel panic
507	{
508	hal_exception_dump( this );
509
510	hal_core_sleep();
511	}
512
513	#if DEBUG_HAL_EXCEPTIONS
514	cycle = (uint32_t)hal_get_cycles();
515	if( DEBUG_HAL_EXCEPTIONS < cycle )
516	printk("\n[%s] thread[%x,%x] exit / core[%x,%d] / epc %x / xcode %x / cycle %d\n",
517	__FUNCTION__, this->process->pid, this->trdid,
518	local_cxy, this->core->lid, excPC, excCode, cycle );
519	#endif
520
521	} // end hal_do_exception()
522
523

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