source: trunk/hal/tsar_mips32/core/hal_vmm.c @ 587

Last change on this file since 587 was 587, checked in by alain, 3 years ago

Modify the GPT (Generic Page Table) API to support remote accesses,
in order to improve page faults and COW handling.

File size: 3.1 KB
Line 
1/*
2 * hal_vmm.c - 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 to initialize the Virtual Memory Manager.
35// The "kentry" vseg contains the kernel code executed when a core enter/exit the kernel,
36// in case of Interrupt, Exception, or Syscall.
37// For the TSAR architecture, the kernel uses physical addresses, and this code must be
38// identity mapped. The following function is called by the generic vmm_init() function
39// and identity map all pages of the "kentry" vseg.
40// We dont take the locks protecting the VSL and the GPT, because there is no concurrent
41// accesses to VMM during VMM initialization.
42//////////////////////////////////////////////////////////////////////////////////////////
43
44////////////////////////////////////
45error_t  hal_vmm_init( vmm_t * vmm )
46{
47    error_t error;
48
49    // map all pages of "kentry" vseg
50    uint32_t vpn;
51    uint32_t attr;
52    attr = GPT_MAPPED | GPT_SMALL | GPT_EXECUTABLE | GPT_CACHABLE | GPT_GLOBAL;
53    for( vpn = CONFIG_VMM_KENTRY_BASE;
54         vpn < (CONFIG_VMM_KENTRY_BASE + CONFIG_VMM_KENTRY_SIZE); vpn++ )
55    {
56        error = hal_gpt_set_pte( XPTR( local_cxy , &vmm->gpt ),
57                                 vpn,
58                                 attr,
59                                 (local_cxy<<20) | (vpn & 0xFFFFF) );
60
61        if( error ) return error;
62    }
63
64    // scan the VSL to found the "kentry" vseg
65    xptr_t         root_xp = XPTR( local_cxy , &vmm->vsegs_root );
66    xptr_t         iter_xp;
67    xptr_t         vseg_xp;
68    vseg_t       * vseg;
69    bool_t         found = false;
70 
71    XLIST_FOREACH( root_xp , iter_xp )
72    {
73        vseg_xp = XLIST_ELEMENT( iter_xp , vseg_t , xlist );
74        vseg    = (vseg_t *)GET_PTR( vseg_xp );
75
76        // set the IDENT flag in "kentry" vseg descriptor
77        if( vseg->vpn_base == CONFIG_VMM_KENTRY_BASE )
78        {
79            vseg->flags |= VSEG_IDENT;
80            found = true;
81            break;
82        }
83    }
84
85    if( found == false ) return 0XFFFFFFFF;
86
87    return 0;
88
89}  // end hal_vmm_init()
90
91
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