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001 /* Copyright (C) 2004 David Decotigny 002 Copyright (C) 2000 The KOS Team 003 004 This program is free software; you can redistribute it and/or 005 modify it under the terms of the GNU General Public License 006 as published by the Free Software Foundation; either version 2 007 of the License, or (at your option) any later version. 008 009 This program is distributed in the hope that it will be useful, 010 but WITHOUT ANY WARRANTY; without even the implied warranty of 011 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 012 GNU General Public License for more details. 013 014 You should have received a copy of the GNU General Public License 015 along with this program; if not, write to the Free Software 016 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, 017 USA. 018 */ 019 #ifndef _SOS_PHYSMEM_H_ 020 #define _SOS_PHYSMEM_H_ 021 022 /** 023 * @file physmem.h 024 * 025 * Physical pages of memory 026 */ 027 028 #include <sos/errno.h> 029 #include <sos/types.h> 030 #include <sos/macros.h> 031 032 /** The size of a physical page (arch-dependent) */ 033 #define SOS_PAGE_SIZE (4*1024) 034 035 /** The corresponding shift */ 036 #define SOS_PAGE_SHIFT 12 /* 4 kB = 2^12 B */ 037 038 /** The corresponding mask */ 039 #define SOS_PAGE_MASK ((1<<12) - 1) 040 041 #define SOS_PAGE_ALIGN_INF(val) \ 042 SOS_ALIGN_INF((val), SOS_PAGE_SIZE) 043 #define SOS_PAGE_ALIGN_SUP(val) \ 044 SOS_ALIGN_SUP((val), SOS_PAGE_SIZE) 045 #define SOS_IS_PAGE_ALIGNED(val) \ 046 SOS_IS_ALIGNED((val), SOS_PAGE_SIZE) 047 048 /** 049 * This is the reserved physical interval for the x86 video memory and 050 * BIOS area. In physmem.c, we have to mark this area as "used" in 051 * order to prevent from allocating it. And in paging.c, we'd better 052 * map it in virtual space if we really want to be able to print to 053 * the screen (for debugging purpose, at least): for this, the 054 * simplest is to identity-map this area in virtual space (note 055 * however that this mapping could also be non-identical). 056 */ 057 #define BIOS_N_VIDEO_START 0xa0000 058 #define BIOS_N_VIDEO_END 0x100000 059 060 061 /** 062 * Initialize the physical memory subsystem, for the physical area [0, 063 * ram_size). This routine takes into account the BIOS and video 064 * areas, to prevent them from future allocations. 065 * 066 * @param ram_size The size of the RAM that will be managed by this subsystem 067 * 068 * @param kernel_core_base The lowest address for which the kernel 069 * assumes identity mapping (ie virtual address == physical address) 070 * will be stored here 071 * 072 * @param kernel_core_top The top address for which the kernel 073 * assumes identity mapping (ie virtual address == physical address) 074 * will be stored here 075 */ 076 sos_ret_t sos_physmem_subsystem_setup(sos_size_t ram_size, 077 /* out */sos_paddr_t *kernel_core_base, 078 /* out */sos_paddr_t *kernel_core_top); 079 080 /** 081 * Retrieve the total number of pages, and the number of free pages 082 */ 083 sos_ret_t sos_physmem_get_state(/* out */sos_count_t *total_ppages, 084 /* out */sos_count_t *used_ppages); 085 086 087 /** 088 * Get a free page. 089 * 090 * @return The (physical) address of the (physical) page allocated, or 091 * NULL when none currently available. 092 * 093 * @param can_block TRUE if the function is allowed to block 094 * @note The page returned has a reference count equal to 1. 095 */ 096 sos_paddr_t sos_physmem_ref_physpage_new(sos_bool_t can_block); 097 098 099 /** 100 * Increment the reference count of a given physical page. Useful for 101 * VM code which tries to map a precise physical address. 102 * 103 * @param ppage_paddr Physical address of the page (MUST be page-aligned) 104 * 105 * @return TRUE when the page was previously in use, FALSE when the 106 * page was previously in the free list, <0 when the page address is 107 * invalid. 108 */ 109 sos_ret_t sos_physmem_ref_physpage_at(sos_paddr_t ppage_paddr); 110 111 112 /** 113 * Decrement the reference count of the given physical page. When this 114 * reference count reaches 0, the page is marked free, ie is available 115 * for future sos_physmem_get_physpage() 116 * 117 * @param ppage_paddr Physical address of the page (MUST be page-aligned) 118 * 119 * @return FALSE when the page is still in use, TRUE when the page is now 120 * unreferenced, <0 when the page address is invalid 121 */ 122 sos_ret_t sos_physmem_unref_physpage(sos_paddr_t ppage_paddr); 123 124 125 #include <sos/kmem_vmm.h> 126 127 /** 128 * Return the kernel memory allocation range associated with the given 129 * physical page, or NULL when page has no associated range 130 * 131 * @param ppage_paddr Physical address of the page (MUST be page-aligned) 132 */ 133 struct sos_kmem_range* sos_physmem_get_kmem_range(sos_paddr_t ppage_paddr); 134 135 136 /** 137 * Set the kernel memory allocation range associated to the given 138 * physical page. 139 * 140 * @param ppage_paddr Physical address of the page (MUST be page-aligned) 141 * 142 * @return error if page is invalid 143 */ 144 sos_ret_t sos_physmem_set_kmem_range(sos_paddr_t ppage_paddr, 145 struct sos_kmem_range *range); 146 147 #endif /* _SOS_PHYSMEM_H_ */
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