|
[ source navigation ] [ diff markup ] [ identifier search ] [ general search ] |
|||
|
001 /* Copyright (C) 2004 David Decotigny 002 003 This program is free software; you can redistribute it and/or 004 modify it under the terms of the GNU General Public License 005 as published by the Free Software Foundation; either version 2 006 of the License, or (at your option) any later version. 007 008 This program is distributed in the hope that it will be useful, 009 but WITHOUT ANY WARRANTY; without even the implied warranty of 010 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 011 GNU General Public License for more details. 012 013 You should have received a copy of the GNU General Public License 014 along with this program; if not, write to the Free Software 015 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 016 USA. 017 */ 018 #ifndef _SOS_PHYSMEM_H_ 019 #define _SOS_PHYSMEM_H_ 020 021 /** 022 * @file physmem.h 023 * 024 * Physical pages of memory 025 */ 026 027 #include <sos/errno.h> 028 #include <sos/types.h> 029 #include <sos/macros.h> 030 031 /** The size of a physical page (arch-dependent) */ 032 #define SOS_PAGE_SIZE (4*1024) 033 034 /** The corresponding shift */ 035 #define SOS_PAGE_SHIFT 12 /* 4 kB = 2^12 B */ 036 037 /** The corresponding mask */ 038 #define SOS_PAGE_MASK ((1<<12) - 1) 039 040 #define SOS_PAGE_ALIGN_INF(val) \ 041 SOS_ALIGN_INF((val), SOS_PAGE_SIZE) 042 #define SOS_PAGE_ALIGN_SUP(val) \ 043 SOS_ALIGN_SUP((val), SOS_PAGE_SIZE) 044 045 046 /** 047 * This is the reserved physical interval for the x86 video memory and 048 * BIOS area. In physmem.c, we have to mark this area as "used" in 049 * order to prevent from allocating it. And in paging.c, we'd better 050 * map it in virtual space if we really want to be able to print to 051 * the screen (for debugging purpose, at least): for this, the 052 * simplest is to identity-map this area in virtual space (note 053 * however that this mapping could also be non-identical). 054 */ 055 #define BIOS_N_VIDEO_START 0xa0000 056 #define BIOS_N_VIDEO_END 0x100000 057 058 059 /** 060 * Initialize the physical memory subsystem, for the physical area [0, 061 * ram_size). This routine takes into account the BIOS and video 062 * areas, to prevent them from future allocations. 063 * 064 * @param ram_size The size of the RAM that will be managed by this subsystem 065 * 066 * @param kernel_core_base The lowest address for which the kernel 067 * assumes identity mapping (ie virtual address == physical address) 068 * will be stored here 069 * 070 * @param kernel_core_top The top address for which the kernel 071 * assumes identity mapping (ie virtual address == physical address) 072 * will be stored here 073 */ 074 sos_ret_t sos_physmem_setup(sos_size_t ram_size, 075 /* out */sos_paddr_t *kernel_core_base, 076 /* out */sos_paddr_t *kernel_core_top); 077 078 /** 079 * Retrieve the total number of pages, and the number of free pages 080 */ 081 sos_ret_t sos_physmem_get_state(/* out */sos_count_t *total_ppages, 082 /* out */sos_count_t *used_ppages); 083 084 085 /** 086 * Get a free page. 087 * 088 * @return The (physical) address of the (physical) page allocated, or 089 * NULL when none currently available. 090 * 091 * @param can_block TRUE if the function is allowed to block 092 * @note The page returned has a reference count equal to 1. 093 */ 094 sos_paddr_t sos_physmem_ref_physpage_new(sos_bool_t can_block); 095 096 097 /** 098 * Increment the reference count of a given physical page. Useful for 099 * VM code which tries to map a precise physical address. 100 * 101 * @return TRUE when the page was previously in use, FALSE when the 102 * page was previously in the free list, <0 when the page address is 103 * invalid. 104 */ 105 sos_ret_t sos_physmem_ref_physpage_at(sos_paddr_t ppage_paddr); 106 107 108 /** 109 * Decrement the reference count of the given physical page. When this 110 * reference count reaches 0, the page is marked free, ie is available 111 * for future sos_physmem_get_physpage() 112 * 113 * @return FALSE when the page is still in use, TRUE when the page is now 114 * unreferenced, <0 when the page address is invalid 115 */ 116 sos_ret_t sos_physmem_unref_physpage(sos_paddr_t ppage_paddr); 117 118 119 #include <sos/kmem_vmm.h> 120 121 /** 122 * Return the kernel memory allocation range associated with the given 123 * physical page, or NULL when page has no associated range 124 */ 125 struct sos_kmem_range* sos_physmem_get_kmem_range(sos_paddr_t ppage_paddr); 126 127 128 /** 129 * Set the kernel memory allocation range associated to the given 130 * physical page. 131 * @return error if page is invalid 132 */ 133 sos_ret_t sos_physmem_set_kmem_range(sos_paddr_t ppage_paddr, 134 struct sos_kmem_range *range); 135 136 #endif /* _SOS_PHYSMEM_H_ */
[ source navigation ] | [ diff markup ] | [ identifier search ] | [ general search ] |