rt-thread/components/mm/mm_fault.c

129 lines
3.2 KiB
C

/*
* Copyright (c) 2006-2022, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2022-12-06 WangXiaoyao the first version
*/
#include <rtthread.h>
#ifdef RT_USING_SMART
#define DBG_TAG "mm.fault"
#define DBG_LVL DBG_INFO
#include <rtdbg.h>
#include <lwp.h>
#include <lwp_syscall.h>
#include "mm_aspace.h"
#include "mm_fault.h"
#include "mm_flag.h"
#include "mm_private.h"
#include <mmu.h>
#include <tlb.h>
#define UNRECOVERABLE 0
#define RECOVERABLE 1
static int _fetch_page(rt_varea_t varea, struct rt_aspace_fault_msg *msg)
{
int err;
msg->response.status = MM_FAULT_STATUS_UNRECOVERABLE;
msg->response.vaddr = 0;
msg->response.size = 0;
if (varea->mem_obj && varea->mem_obj->on_page_fault)
{
varea->mem_obj->on_page_fault(varea, msg);
err = _varea_map_with_msg(varea, msg);
err = (err == RT_EOK ? RECOVERABLE : UNRECOVERABLE);
}
return err;
}
static int _read_fault(rt_varea_t varea, void *pa, struct rt_aspace_fault_msg *msg)
{
int err = UNRECOVERABLE;
if (msg->fault_type == MM_FAULT_TYPE_PAGE_FAULT)
{
RT_ASSERT(pa == ARCH_MAP_FAILED);
RT_ASSERT(!(varea->flag & MMF_PREFETCH));
err = _fetch_page(varea, msg);
}
else
{
/* signal a fault to user? */
}
return err;
}
static int _write_fault(rt_varea_t varea, void *pa, struct rt_aspace_fault_msg *msg)
{
int err = UNRECOVERABLE;
if (msg->fault_type == MM_FAULT_TYPE_PAGE_FAULT)
{
RT_ASSERT(pa == ARCH_MAP_FAILED);
RT_ASSERT(!(varea->flag & MMF_PREFETCH));
err = _fetch_page(varea, msg);
}
else if (msg->fault_type == MM_FAULT_TYPE_ACCESS_FAULT &&
varea->flag & MMF_COW)
{
}
else
{
/* signal a fault to user? */
}
return err;
}
static int _exec_fault(rt_varea_t varea, void *pa, struct rt_aspace_fault_msg *msg)
{
int err = UNRECOVERABLE;
if (msg->fault_type == MM_FAULT_TYPE_PAGE_FAULT)
{
RT_ASSERT(pa == ARCH_MAP_FAILED);
RT_ASSERT(!(varea->flag & MMF_PREFETCH));
err = _fetch_page(varea, msg);
}
return err;
}
int rt_aspace_fault_try_fix(struct rt_aspace_fault_msg *msg)
{
struct rt_lwp *lwp = lwp_self();
int err = UNRECOVERABLE;
uintptr_t va = (uintptr_t)msg->fault_vaddr;
va &= ~ARCH_PAGE_MASK;
msg->fault_vaddr = (void *)va;
if (lwp)
{
rt_aspace_t aspace = lwp->aspace;
rt_varea_t varea = _aspace_bst_search(aspace, msg->fault_vaddr);
if (varea)
{
void *pa = rt_hw_mmu_v2p(aspace, msg->fault_vaddr);
msg->off = (msg->fault_vaddr - varea->start) >> ARCH_PAGE_SHIFT;
/* permission checked by fault op */
switch (msg->fault_op)
{
case MM_FAULT_OP_READ:
err = _read_fault(varea, pa, msg);
break;
case MM_FAULT_OP_WRITE:
err = _write_fault(varea, pa, msg);
break;
case MM_FAULT_OP_EXECUTE:
err = _exec_fault(varea, pa, msg);
break;
}
}
}
return err;
}
#endif /* RT_USING_SMART */