/*
* Copyright (c) 2006 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup kernel_generic_mm
* @{
*/
/**
* @file
* @brief Backend for address space areas backed by continuous physical
* memory.
*/
#include <assert.h>
#include <ddi/ddi.h>
#include <typedefs.h>
#include <mm/as.h>
#include <mm/page.h>
#include <mm/frame.h>
#include <stdlib.h>
#include <macros.h>
#include <arch.h>
#include <align.h>
static bool phys_create(as_area_t *);
static void phys_share(as_area_t *);
static void phys_destroy(as_area_t *);
static bool phys_is_resizable(as_area_t *);
static bool phys_is_shareable(as_area_t *);
static int phys_page_fault(as_area_t *, uintptr_t, pf_access_t);
static bool phys_create_shared_data(as_area_t *);
static void phys_destroy_shared_data(void *);
typedef struct {
uintptr_t base;
size_t frames;
} phys_shared_data_t;
mem_backend_t phys_backend = {
.create = phys_create,
.resize = NULL,
.share = phys_share,
.destroy = phys_destroy,
.is_resizable = phys_is_resizable,
.is_shareable = phys_is_shareable,
.page_fault = phys_page_fault,
.frame_free = NULL,
.create_shared_data = phys_create_shared_data,
.destroy_shared_data = phys_destroy_shared_data
};
bool phys_create(as_area_t *area)
{
return true;
}
/** Share address space area backed by physical memory.
*
* Do actually nothing as sharing of address space areas
* that are backed up by physical memory is very easy.
* Note that the function must be defined so that
* as_area_share() will succeed.
*/
void phys_share(as_area_t *area)
{
assert(mutex_locked(&area->as->lock));
assert(mutex_locked(&area->lock));
}
void phys_destroy(as_area_t *area)
{
/*
* The anonymous frames, if any, are released in
* phys_destroy_shared_data().
*/
/* Notify parea has been unmapped */
if (area->backend_data.parea != NULL)
ddi_parea_unmap_notify(area->backend_data.parea);
}
bool phys_is_resizable(as_area_t *area)
{
return false;
}
bool phys_is_shareable(as_area_t *area)
{
return true;
}
/** Service a page fault in the address space area backed by physical memory.
*
* The address space area and page tables must be already locked.
*
* @param area Pointer to the address space area.
* @param upage Faulting virtual page.
* @param access Access mode that caused the fault (i.e. read/write/exec).
*
* @return AS_PF_FAULT on failure (i.e. page fault) or AS_PF_OK on success (i.e.
* serviced).
*/
int phys_page_fault(as_area_t *area, uintptr_t upage, pf_access_t access)
{
uintptr_t base = area->backend_data.base;
assert(page_table_locked(AS));
assert(mutex_locked(&area->lock));
assert(IS_ALIGNED(upage, PAGE_SIZE));
if (!as_area_check_access(area, access))
return AS_PF_FAULT;
assert(upage - area->base < area->backend_data.frames * FRAME_SIZE);
page_mapping_insert(AS, upage, base + (upage - area->base),
as_area_get_flags(area));
if (!used_space_insert(&area->used_space, upage, 1))
panic("Cannot insert used space.");
return AS_PF_OK;
}
bool phys_create_shared_data(as_area_t *area)
{
/*
* For anonymous phys areas, create the shared data.
*/
if (area->backend_data.anonymous) {
phys_shared_data_t *data;
data = (phys_shared_data_t *) malloc(sizeof(*data));
if (!data)
return false;
data->base = area->backend_data.base;
data->frames = area->backend_data.frames;
area->sh_info->backend_shared_data = data;
}
return true;
}
void phys_destroy_shared_data(void *opaque_data)
{
phys_shared_data_t *data = (phys_shared_data_t *) opaque_data;
if (data) {
frame_free(data->base, data->frames);
free(data);
}
}
/** @}
*/