source: soft/giet_vm/giet_kernel/kernel_init.c @ 312

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1///////////////////////////////////////////////////////////////////////////////////
2// File     : kernel_init.c
3// Date     : 26/05/2012
4// Authors  : alain greiner & mohamed karaoui
5// Copyright (c) UPMC-LIP6
6////////////////////////////////////////////////////////////////////////////////////
7// The kernel_init.c file is part of the GIET-VM nano-kernel.
8//
9// This nano-kernel has been written for the MIPS32 processor.
10// The virtual adresses are on 32 bits and use the (unsigned int) type, but the
11// physicals addresses can have up to 40 bits, and use the (unsigned long long) type.
12// It natively supports clusterised shared mmemory multi-processors architectures,
13// where each processor is identified by a composite index [x,y,lpid],
14// and where there is one physical memory bank per cluster.
15//
16// The kernel_init() function is executed in parallel by all procesors,
17// and completes the system initialisation that has been started by processor[0,0,0]
18// in the boot_init() function. It makes the following assuptions, regarding the work
19// bone by the boot code:
20//
21// 1) The page tables associated to the various vspaces have been build
22//    in physical memory, and can be used by the kernel code.
23//
24// 2) All schedulers (this include all task contexts) have been initialised,
25//    Both the virtual and the physical base addresses of the page tables
26//    are available in the CTX_PTAB and CTX_PTPR slots.
27//
28// 3) The CP0_SCHED register of each processor contains a pointer on its
29//    private scheduler (virtual address).
30//
31// 4) The CP2_PTPR register of each processor contains a pointer on
32//    the vspace_0 page table (physical address>>13).
33//
34// 5) For all processors, the MMU is activated (CP2_MODE contains 0xF).
35//
36// This code must be loaded in .kinit section, in order to control seg_kinit_base,
37// as this address is used by the boot code to jump into kernel code.
38//
39// Each processor performs the following actions:
40// 1/ contribute to _schedulers_paddr[] array initialisation.
41// 2/ contribute to _ptabs_paddr[] and _ptabs_vaddr arrays initialisation
42// 3/ completes task context initialisation for ech allocated task
43// 4/ compute and set the ICU mask for its private ICU channel
44// 5/ initialise its private TICK timer (if tasks > 0)
45// 6/ initialise the "idle" task context in its private scheduler
46// 7/ initialise SP, SR, PTPR, EPC registers and jump to user code with an eret.
47////////////////////////////////////////////////////////////////////////////////////
48
49#include <giet_config.h>
50
51// kernel libraries
52#include <utils.h>
53#include <fat32.h>
54
55//for peripheral initialisation
56#include <dma_driver.h>
57#include <fbf_driver.h>
58#include <tty_driver.h>
59#include <icu_driver.h>
60#include <xcu_driver.h>
61#include <ioc_driver.h>
62#include <mmc_driver.h>
63#include <mwr_driver.h>
64#include <nic_driver.h>
65#include <tim_driver.h>
66
67#include <ctx_handler.h>
68#include <irq_handler.h>
69
70#include <mapping_info.h>
71#include <mips32_registers.h>
72
73///////////////////////////////////////////////////////////////////////////////////
74// array of pointers on the page tables (virtual addresses)
75///////////////////////////////////////////////////////////////////////////////////
76
77__attribute__((section (".kdata"))) 
78unsigned int _ptabs_vaddr[GIET_NB_VSPACE_MAX];    // virtual addresses
79
80__attribute__((section (".kdata")))       
81unsigned int _ptabs_ptprs[GIET_NB_VSPACE_MAX];    // physical addresses >> 13
82
83///////////////////////////////////////////////////////////////////////////////////
84// array of pointers on the schedulers (physical addresses)
85///////////////////////////////////////////////////////////////////////////////////
86
87__attribute__((section (".kdata"))) 
88static_scheduler_t* _schedulers[NB_PROCS_MAX<<(X_WIDTH+Y_WIDTH)]; // virtual addresses
89
90////////////////////////////////////////////////////////////////////////////////////
91// staks for the "idle" tasks (512 bytes for each processor)
92////////////////////////////////////////////////////////////////////////////////////
93
94__attribute__((section (".kdata"))) 
95unsigned int _idle_stack[X_SIZE * Y_SIZE * NB_PROCS_MAX * 128 ]; 
96
97////////////////////////////////////////////////////////////////////////////////////
98// Synchonisation Barrier before jumping to user code
99////////////////////////////////////////////////////////////////////////////////////
100
101__attribute__((section (".kdata"))) 
102unsigned int _init_barrier = 0;
103
104///////////////////////////////////////////////////////////////////////////////////
105__attribute__((section (".kinit"))) void kernel_init() 
106{
107    unsigned int global_pid = _get_procid();
108    unsigned int cluster_xy = global_pid / NB_PROCS_MAX;
109    unsigned int x          = cluster_xy >> Y_WIDTH;
110    unsigned int y          = cluster_xy & ((1<<Y_WIDTH)-1);
111    unsigned int lpid       = global_pid % NB_PROCS_MAX;
112    unsigned int nprocs     = TOTAL_PROCS;
113    unsigned int pid        = ((( x * Y_SIZE) + y) * NB_PROCS_MAX) + lpid;
114//  unsigned int pid        = _get_id(i n_procs );
115
116    // This last initialisation phase is done sequencially:
117    while( pid != _init_barrier ) asm volatile ( "nop" );
118
119    // Step 1 : each processor get its scheduler virtual address
120    //          and contribute to initialise the _schedulers[] array
121
122    static_scheduler_t* psched     = (static_scheduler_t*)_get_sched();
123    unsigned int        tasks      = psched->tasks;
124
125    _schedulers[global_pid] = psched;
126
127#if GIET_DEBUG_INIT
128_printf("\n[GIET DEBUG INIT] Processor[%d,%d,%d] starts kernel init\n"
129        " - scheduler vbase = %x\n"
130        " - tasks           = %d\n",
131        x, y, lpid, (unsigned int)psched, tasks );
132#endif
133
134    // step 2 : each processor that is allocated at least one task loops
135    //          on all allocated tasks:
136    //          - contributes to _ptabs_vaddr[] & _ptabs_ptprs[] initialisation.
137    //          - set CTX_RA slot  with the kernel _ctx_eret() virtual address.
138    //          - set CTX_EPC slot that must contain the task entry point,
139    //            and contain only at this point the virtual address of the memory
140    //            location containing this entry point. We must switch the PTPR
141    //            to use the page table corresponding to the task.
142
143    unsigned int ltid;
144
145    for (ltid = 0; ltid < tasks; ltid++) 
146    {
147        unsigned int vsid = _get_task_slot( global_pid, ltid , CTX_VSID_ID ); 
148        unsigned int ptab = _get_task_slot( global_pid, ltid , CTX_PTAB_ID ); 
149        unsigned int ptpr = _get_task_slot( global_pid, ltid , CTX_PTPR_ID ); 
150
151        // initialize PTABS arrays
152        _ptabs_vaddr[vsid] = ptab;
153        _ptabs_ptprs[vsid] = ptpr;
154
155#if GIET_DEBUG_INIT
156_printf("\n[GIET DEBUG INIT] Processor[%d,%d,%d] contributes to PTABS arrays\n"
157        " - ptabs_vaddr[%d] = %x / ptpr_paddr[%d] = %l\n",
158        x, y, lpid, 
159        vsid, ptab, vsid, ((unsigned long long)ptpr)<<13 );
160#endif
161
162        // set the ptpr to use the task page table
163        asm volatile( "mtc2    %0,   $0   \n"
164                      : : "r" (ptpr) );
165
166        // compute ctx_ra
167        unsigned int ctx_ra = (unsigned int)(&_ctx_eret);
168        _set_task_slot( global_pid, ltid, CTX_RA_ID, ctx_ra );
169
170        // compute ctx_epc
171        unsigned int* ptr = (unsigned int*)_get_task_slot( global_pid, ltid, CTX_EPC_ID );
172        _set_task_slot( global_pid, ltid, CTX_EPC_ID, *ptr );
173
174#if GIET_DEBUG_INIT
175_printf("\n[GIET DEBUG INIT] Processor[%d,%d,%d] updates context for task %d\n"
176        " - ctx_epc   = %x\n"
177        " - ctx_ra    = %x\n",
178        x, y, lpid, ltid,
179        _get_task_slot( global_pid, ltid, CTX_EPC_ID ),
180        _get_task_slot( global_pid, ltid, CTX_RA_ID ) );
181#endif
182
183    }  // end for tasks
184
185    // step 4 : compute and set ICU or XCU masks
186
187    unsigned int isr_switch_index = 0xFFFFFFFF;
188    unsigned int hwi_mask = 0;
189    unsigned int pti_mask = 0;
190    unsigned int wti_mask = 0;
191    unsigned int irq_id;            // IN_IRQ index
192    unsigned int entry;             // interrupt vector entry
193
194    for (irq_id = 0; irq_id < 32; irq_id++) 
195    {
196        entry = psched->hwi_vector[irq_id];
197        if ( entry & 0x80000000 ) hwi_mask = hwi_mask | (1<<irq_id);
198        if ( (entry & 0x0000FFFF) == ISR_TICK ) isr_switch_index = irq_id;
199
200        entry = psched->pti_vector[irq_id];
201        if ( entry & 0x80000000 ) pti_mask = pti_mask | (1<<irq_id);
202        if ( (entry & 0x0000FFFF) == ISR_TICK ) isr_switch_index = irq_id;
203
204        entry = psched->wti_vector[irq_id];
205        if ( entry & 0x80000000 ) wti_mask = wti_mask | (1<<irq_id);
206        if ( (entry & 0x0000FFFF) == ISR_TICK ) isr_switch_index = irq_id;
207    }
208
209#if GIET_DEBUG_INIT
210_printf("\n[GIET DEBUG INIT] Processor[%d,%d,%d] sets XCU masks\n"
211        " - ICU HWI_MASK = %x\n"
212        " - ICU WTI_MASK = %x\n"
213        " - ICU PTI_MASK = %x\n",
214        x, y, lpid, hwi_mask, wti_mask, pti_mask );
215#endif
216
217    unsigned int channel = lpid * IRQ_PER_PROCESSOR; 
218
219#if USE_XICU
220    _xcu_set_mask( cluster_xy, channel, hwi_mask, IRQ_TYPE_HWI ); 
221    _xcu_set_mask( cluster_xy, channel, wti_mask, IRQ_TYPE_WTI );
222    _xcu_set_mask( cluster_xy, channel, pti_mask, IRQ_TYPE_PTI );
223#else
224    _icu_set_mask( cluster_xy, channel, hwi_mask );   
225#endif
226
227    // step 5 : start TICK timer if at least one task
228    if (tasks > 0) 
229    {
230        // one ISR_TICK must be defined for each proc
231        if (isr_switch_index == 0xFFFFFFFF) 
232        {
233            _printf("\n[GIET ERROR] ISR_TICK not found for processor[%d,%d,%d]\n",
234                    x, y, lpid );
235            _exit();
236        }
237
238        // start system timer
239
240#if USE_XICU
241        _xcu_timer_start( cluster_xy, isr_switch_index, GIET_TICK_VALUE ); 
242#else
243        _timer_start( cluster_xy, isr_switch_index, GIET_TICK_VALUE ); 
244#endif
245
246    }
247
248#if GIET_DEBUG_INIT
249_printf("\n[GIET DEBUG INIT] Processor[%d,%d,%d] starts TICK timer\n",
250        x, y, lpid );
251#endif
252
253    // step 6 : each processor updates the idle_task context:
254    //          (only CTX_SP, CTX_RA, CTX_EPC).
255    //          The stack size is 512 bytes, reserved in seg_kdata.
256    //          The PTPR register, the CTX_PTPR and CTX_PTAB slots
257    //          have been initialised in boot code.
258
259    unsigned int p = ((x * Y_SIZE) + y) * NB_PROCS_MAX + lpid; 
260
261    unsigned int stack = (unsigned int)_idle_stack + ((p + 1)<<9);
262
263    _set_task_slot( global_pid, IDLE_TASK_INDEX, CTX_SP_ID,  stack);
264    _set_task_slot( global_pid, IDLE_TASK_INDEX, CTX_RA_ID,  (unsigned int) &_ctx_eret);
265    _set_task_slot( global_pid, IDLE_TASK_INDEX, CTX_EPC_ID, (unsigned int) &_idle_task);
266
267#if GIET_DEBUG_INIT
268_printf("\n[GIET DEBUG INIT] Processor[%d,%d,%d] initializes IDLE task\n",
269        x, y, lpid );
270#endif
271
272    // step 7 : when all processors reach the synchronisation barrier,
273    //          each processor set registers SP, SR, PTPR, EPC,
274    //          with the values corresponding to the first allocated task,
275    //          or to the idle_task if there is no task allocated,
276    //          and jump to user code
277
278    if (tasks == 0) 
279    {
280        ltid = IDLE_TASK_INDEX;
281
282        _printf("\n[GIET WARNING] No task allocated to processor[%d,%d,%d]\n",
283                x, y, lpid );
284    }
285    else
286    {
287        ltid = 0;
288    }
289
290    unsigned int sp_value   = _get_task_slot(global_pid, ltid, CTX_SP_ID);
291    unsigned int sr_value   = _get_task_slot(global_pid, ltid, CTX_SR_ID);
292    unsigned int ptpr_value = _get_task_slot(global_pid, ltid, CTX_PTPR_ID);
293    unsigned int epc_value  = _get_task_slot(global_pid, ltid, CTX_EPC_ID);
294
295    _printf("\n[GIET DEBUG INIT] Processor[%d,%d,%d] reach barrier at cycle %d\n",
296            x, y, lpid, _get_proctime() );
297
298/*
299    unsigned int*  pcount = &_init_barrier;
300    unsigned int   count;
301
302    // increment barrier counter with atomic LL/SC
303    asm volatile ( "_init_barrier_loop:             \n"
304                   "ll    %0,   0(%1)               \n"
305                   "addi  $3,   %0,   1             \n"
306                   "sc    $3,   0(%1)               \n"
307                   "beqz  $3,   _init_barrier_loop  \n"
308                   "nop                             \n"
309                   : "=&r"(count)
310                   : "r"(pcount)
311                   : "$3" );
312   
313    // busy waiting until all processors synchronized
314    while ( *pcount != nprocs ) asm volatile ("nop");
315*/
316
317    // increment barrier counter
318    _init_barrier++;
319
320    // busy waiting until all processors synchronized
321    while ( _init_barrier != nprocs ) asm volatile ("nop");
322
323/*
324    _printf("\n[GIET] Processor[%d,%d,%d] jumps to user code at cycle %d\n",
325            x, y, lpid, _get_proctime() );
326*/
327       
328    // set registers and jump to user code
329    asm volatile ( "move  $29,  %0                  \n"   /* SP <= ctx[CTX_SP_ID] */
330                   "mtc0  %1,   $12                 \n"   /* SR <= ctx[CTX_SR_ID] */
331                   "mtc2  %2,   $0                  \n"   /* PTPR <= ctx[CTX_PTPR] */
332                   "mtc0  %3,   $14                 \n"   /* EPC <= ctx[CTX_EPC]  */
333                   "eret                            \n"   /* jump to user code  */
334                   "nop                             \n"
335                   : 
336                   : "r"(sp_value), "r"(sr_value), "r"(ptpr_value), "r"(epc_value)
337                   : "$29" );
338
339} // end kernel_init()
340
341
342// Local Variables:
343// tab-width: 4
344// c-basic-offset: 4
345// c-file-offsets:((innamespace . 0)(inline-open . 0))
346// indent-tabs-mode: nil
347// End:
348// vim: filetype=c:expandtab:shiftwidth=4:tabstop=4:softtabstop=4
349
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