/*
* Copyright (c) 2016 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 the user pager.
*
*/
#include <mm/as.h>
#include <mm/page.h>
#include <mm/frame.h>
#include <abi/mm/as.h>
#include <abi/ipc/methods.h>
#include <ipc/sysipc.h>
#include <synch/mutex.h>
#include <typedefs.h>
#include <align.h>
#include <assert.h>
#include <errno.h>
#include <log.h>
#include <str.h>
#include <str_error.h>
static bool user_create(as_area_t *);
static void user_destroy(as_area_t *);
static bool user_is_resizable(as_area_t *);
static bool user_is_shareable(as_area_t *);
static int user_page_fault(as_area_t *, uintptr_t, pf_access_t);
static void user_frame_free(as_area_t *, uintptr_t, uintptr_t);
mem_backend_t user_backend = {
.create = user_create,
.resize = NULL,
.share = NULL,
.destroy = user_destroy,
.is_resizable = user_is_resizable,
.is_shareable = user_is_shareable,
.page_fault = user_page_fault,
.frame_free = user_frame_free,
.create_shared_data = NULL,
.destroy_shared_data = NULL
};
bool user_create(as_area_t *area)
{
return true;
}
void user_destroy(as_area_t *area)
{
return;
}
bool user_is_resizable(as_area_t *area)
{
return false;
}
bool user_is_shareable(as_area_t *area)
{
return false;
}
/** Service a page fault in the user-paged address space area.
*
* 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 user_page_fault(as_area_t *area, uintptr_t upage, pf_access_t access)
{
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;
as_area_pager_info_t *pager_info = &area->backend_data.pager_info;
ipc_data_t data = { };
ipc_set_imethod(&data, IPC_M_PAGE_IN);
ipc_set_arg1(&data, upage - area->base);
ipc_set_arg2(&data, PAGE_SIZE);
ipc_set_arg3(&data, pager_info->id1);
ipc_set_arg4(&data, pager_info->id2);
ipc_set_arg5(&data, pager_info->id3);
errno_t rc = ipc_req_internal(pager_info->pager, &data, (sysarg_t) true);
if (rc != EOK) {
log(LF_USPACE, LVL_FATAL,
"Page-in request for page %#" PRIxPTR
" at pager %p failed with error %s.",
upage, pager_info->pager, str_error_name(rc));
return AS_PF_FAULT;
}
if (ipc_get_retval(&data) != EOK)
return AS_PF_FAULT;
/*
* A successful reply will contain the physical frame in ARG1.
* The physical frame will have the reference count already
* incremented (if applicable).
*/
uintptr_t frame = ipc_get_arg1(&data);
page_mapping_insert(AS, upage, frame, as_area_get_flags(area));
if (!used_space_insert(&area->used_space, upage, 1))
panic("Cannot insert used space.");
return AS_PF_OK;
}
/** Free a frame that is backed by the user memory backend.
*
* The address space area and page tables must be already locked.
*
* @param area Ignored.
* @param page Virtual address of the page corresponding to the frame.
* @param frame Frame to be released.
*/
void user_frame_free(as_area_t *area, uintptr_t page, uintptr_t frame)
{
assert(page_table_locked(area->as));
assert(mutex_locked(&area->lock));
pfn_t pfn = ADDR2PFN(frame);
if (find_zone(pfn, 1, 0) != (size_t) -1) {
frame_free(frame, 1);
} else {
/* Nothing to do */
}
}
/** @}
*/