/* Copyright (C) 2000 Thomas Petazzoni
    Copyright (C) 2004 David Decotigny
 
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License
    as published by the Free Software Foundation; either version 2
    of the License, or (at your option) any later version.
    
    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.
    
    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
    USA. 
 */
 #ifndef _SOS_KMEM_VMM_H_
 #define _SOS_KMEM_VMM_H_
 
 /**
  * @file kmem_vmm.h
  *
  * Kernel Memory Allocator for multiple-page-sized objects residing in
  * the kernel (virtual memory) space. Relies on the slab cache
  * allocator to allocate its (internal) "range" data structure.
  */
 
 #include <hwcore/paging.h>
 
 /* The base and top virtual addresses covered by the kernel allocator */
 #define SOS_KMEM_VMM_BASE 0x4000 /* 16kB */
 #define SOS_KMEM_VMM_TOP  SOS_PAGING_MIRROR_VADDR /* 1GB - 4MB */
 
 /** Opaque structure used internally and declared here for physmem.h */
 struct sos_kmem_range;
 
 #include <sos/kmem_slab.h>
 
 /**
  * Mark the areas belonging to SOS_KMEM_VMM_BASE and SOS_KMEM_VMM_TOP
  * are either used or free. Those that are already mapped are marked
  * as "used", and the 0..SOS_KMEM_VMM_BASE virtual addresses as marked
  * as "used" too (to detect incorrect pointer dereferences).
  */
 sos_ret_t
 sos_kmem_vmm_subsystem_setup(sos_vaddr_t kernel_core_base_vaddr,
                              sos_vaddr_t kernel_core_top_vaddr,
                              sos_vaddr_t bootstrap_stack_bottom_vaddr,
                              sos_vaddr_t bootstrap_stack_top_vaddr);
 
 
 /*
  * Flags for kmem_vmm_new_range and kmem_vmm_alloc
  */
 /** Physical pages should be immediately mapped */
 #define SOS_KMEM_VMM_MAP    (1<<0)
 /** Allocation should either success or fail, without blocking */
 #define SOS_KMEM_VMM_ATOMIC (1<<1)
 
 /**
  * Allocate a new kernel area spanning one or multiple pages.
  *
  * @param range_base_vaddr If not NULL, the start address of the range
  * is stored in this location
  * @eturn a new range structure
  */
 struct sos_kmem_range *sos_kmem_vmm_new_range(sos_size_t  nb_pages,
                                               sos_ui32_t  flags,
                                               sos_vaddr_t *range_base_vaddr);
 sos_ret_t sos_kmem_vmm_del_range(struct sos_kmem_range *range);
 
 
 /**
  * Straighforward variant of sos_kmem_vmm_new_range() returning the
  * range's start address instead of the range structure
  */
 sos_vaddr_t sos_kmem_vmm_alloc(sos_size_t nb_pages,
                                sos_ui32_t flags);
 
 /**
  * @note you are perfectly allowed to give the address of the
  * kernel image, or the address of the bios area here, it will work:
  * the kernel/bios WILL be "deallocated". But if you really want to do
  * this, well..., do expect some "surprises" ;)
  */
 sos_ret_t sos_kmem_vmm_free(sos_vaddr_t vaddr);
 
 
 /**
  * @return TRUE when vaddr is covered by any (used) kernel range
  */
 sos_bool_t sos_kmem_vmm_is_valid_vaddr(sos_vaddr_t vaddr);
 
 
 /* *****************************
  * Reserved to kmem_slab.c ONLY.
  */
 /**
  * Associate the range with the given slab.
  */
 sos_ret_t sos_kmem_vmm_set_slab(struct sos_kmem_range *range,
                                 struct sos_kslab *slab);
 
 /**
  * Retrieve the (used) slab associated with the range covering vaddr.
  *
  * @return NULL if the range is not associated with a KMEM range
  */
 struct sos_kslab *sos_kmem_vmm_resolve_slab(sos_vaddr_t vaddr);
 
 #endif /* _SOS_KMEM_VMM_H_ */