source: trunk/hal/tsar_mips32/core/hal_vmm.c @ 548

Last change on this file since 548 was 457, checked in by alain, 6 years ago

This version modifies the exec syscall and fixes a large number of small bugs.
The version number has been updated (0.1)

File size: 3.2 KB
Line 
1/*
2 * hal_vmm.c - Generic Virtual Memory Manager Initialisation for TSAR
3 *
4 * Authors  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 <kernel_config.h>
25#include <hal_kernel_types.h>
26#include <hal_vmm.h>
27#include <hal_gpt.h>
28#include <vseg.h>
29#include <xlist.h>
30#include <vmm.h>
31#include <remote_rwlock.h>
32
33//////////////////////////////////////////////////////////////////////////////////////////
34// This file contains the TSAR specific code for the Virtual Memory Manager.
35//
36// The "kentry" vseg contains the kernel code executed when a core enter/exit the kernel,
37// in case of Interrupt, Exception, or Syscall.
38// For the TSAR architecture, the kernel uses physical addresses, and this code must be
39// identity mapped. The following function is called by the generic vmm_init() function
40// and identity map all pages of the "kentry" vseg.
41//////////////////////////////////////////////////////////////////////////////////////////
42
43////////////////////////////////////
44error_t  hal_vmm_init( vmm_t * vmm )
45{
46    error_t error;
47
48    // get pointer on GPT
49    gpt_t * gpt = &vmm->gpt;
50
51    // map all pages of "kentry" vseg
52    uint32_t vpn;
53    uint32_t attr;
54    attr = GPT_MAPPED | GPT_SMALL | GPT_EXECUTABLE | GPT_CACHABLE | GPT_GLOBAL;
55    for( vpn = CONFIG_VMM_KENTRY_BASE;
56         vpn < (CONFIG_VMM_KENTRY_BASE + CONFIG_VMM_KENTRY_SIZE); vpn++ )
57    {
58        error = hal_gpt_set_pte( gpt,
59                                 vpn,
60                                 attr,
61                                 (local_cxy<<20) | (vpn & 0xFFFFF) );
62
63        if( error ) return error;
64    }
65
66    // get lock protecting the VSL to found the "kentry" vseg
67    remote_rwlock_wr_lock( XPTR( local_cxy , &vmm->vsegs_lock ) );
68
69    // scan the VSL
70    xptr_t         root_xp = XPTR( local_cxy , &vmm->vsegs_root );
71    xptr_t         iter_xp;
72    xptr_t         vseg_xp;
73    vseg_t       * vseg;
74    bool_t         found = false; 
75    XLIST_FOREACH( root_xp , iter_xp )
76    {
77        vseg_xp = XLIST_ELEMENT( iter_xp , vseg_t , xlist );
78        vseg    = (vseg_t *)GET_PTR( vseg_xp );
79
80        // set the IDENT flag in "kentry" vseg descriptor
81        if( vseg->vpn_base == CONFIG_VMM_KENTRY_BASE )
82        {
83            vseg->flags |= VSEG_IDENT;
84            found = true;
85            break;
86        }
87    }
88
89    // release the lock protecting the VSL
90    remote_rwlock_wr_unlock( XPTR( local_cxy , &vmm->vsegs_lock ) );
91
92    if( found == false ) return error;
93
94    return 0;
95
96}  // end hal_vmm_init()
97
98
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