/*
* void init_paging()
* Description: Initializes page directories, tables and control registers
* Inputs: none
* Return Value: none
*/
void init_paging()
{
// Set up program page (physical) address array
uint32_t i;
for(i = 0; i < NUM_PD; i++)
{
PGRM_PAGE[i] = PAGE1 + i * PAGE_SIZE;
}
// Initialize the Page directory
init_PD();
// Initialize the video page table
init_VIDEO_PT();
// Set PSE bit in CR4
set_PSE();
// Set PG bit in CR0
set_PG();
// Set PGE bit in CR4
set_PGE();
INVLPG(VIDEO_MEM);
INVLPG(KERNEL_MEM);
//test_paging();
}
/*
* kmem_map_page_frame_cur(p_adr, v_adr, pages, flags)
*
* Maps an area of 'pages' page frames at address 'p_adr'
* into a virtual address space defined by the currently
* active page directory to the virtual address 'v_adr'.
*
* You can define the access flags of this pages through
* the 'flags' parameter.
*
* If a page should be mapped to an area of the virtual
* address space that currently isn't described by a
* page table, the function will automatically allocate
* and map a new page table.
*
* The function will neither free page frames, that will
* be removed from the address space nor change the
* usage counter of the selected page frames.
*
* This function will also invalidate the TLB of the
* selected pages.
*
* ! If you want to map a page into the current virtual
* ! address space YO HAVE TO use kmem_map_page_frame_cur
* ! to prevent the use of an invalid TLB content.
*
* Using the flag GENFLAG_DONT_OVERWRITE_SETTINGS will prevent
* that the function overwrites existing areas.
*
* Return Value:
* == 0 Successful
* > 0 n pages have been skipped
* < 0 Error (not enough memory to allocate a new page table)
*
*/
long kmem_map_page_frame_cur(uintptr_t p_adr,
uintptr_t v_adr,
unsigned long pages,
unsigned flags
)
{
/* Map the pages */
long l__retval =
kmem_map_page_frame(i386_current_pdir,
¤t_p[PRCTAB_X86_MMTABLE],
p_adr,
v_adr,
pages,
flags
);
v_adr &= (~0xFFF);
/* Invalidate the TLB */
while (pages --)
{
INVLPG(v_adr);
v_adr += 4096;
}
return l__retval;
}
/*
* uint8_t* user_vidmap()
* Description: Maps video memory for a user process
* Inputs: none
* Return Value: A pointer to the newly mapped virtual memory
*/
uint8_t* user_vidmap()
{
// Set up PTE if necessary
uint32_t PT_index = get_PTE_offset(USER_VID);
if(PT[1][PT_index].present == 0)
{
PTE_t PTE_video;
PTE_video = PTE_default;
PTE_video.user_super = 1;
PTE_video.read_write = 1;
SET_PTE(PTE_video, VIDEO_MEM);
PT[1][PT_index] = PTE_video;
}
// Set up PDE if necessary
uint32_t PD_index = get_PDE_offset(USER_VID);
if(cur_PD[PD_index].present == 0)
{
PDE_t PDE_video;
PDE_video = PDE_default;
PDE_video.user_super = 1;
PDE_video.read_write = 1;
SET_PDE_4KB_PT(PDE_video, PT[1]);
cur_PD[PD_index] = PDE_video;
}
INVLPG(USER_VID);
return (uint8_t*)USER_VID;
}
kern_obj * spawn_process(const uchar * cd, ulong csz, ulong dsz, ulong bsz, kern_obj * par, uchar priv, uchar priority)
{
ulong i, pbase, ssz, absz, pgs;
kern_obj * proc = alloc_kobj();
ssz = csz + dsz;
absz = bsz;
if (csz % 0x1000 != 0) csz = csz - (csz % 0x1000) + 0x1000;
if (dsz % 0x1000 != 0) dsz = dsz - (dsz % 0x1000) + 0x1000;
if (bsz % 0x1000 != 0) bsz = bsz - (bsz % 0x1000) + 0x1000;
proc->type = KOBJ_PROCESS;
proc->u.proc.parent = par;
proc->u.proc.priv = priv;
proc->u.proc.priority = priority;
proc->u.proc.code_data_ws = alloc_ws();
pgs = csz / 0x1000 + dsz / 0x1000 + bsz / 0x1000;
pbase = alloc_pages(pgs + 0x200, PHYS_PAGES);
if (pbase == 0) {
free_kobj(proc);
return NULL;
}
add_pgs_to_ws(proc->u.proc.code_data_ws, USPACE_BOT, pbase, csz + dsz + bsz + 0x200000, 7);
for (i = 0; i < ssz + absz; i++) {
if (i % 0x1000 == 0) {
ATQ(KPT0_0_LOC) = (pbase + i) | 3;
INVLPG(KSPACE_LOC);
}
if (i < ssz) ATB(KSPACE_LOC + i % 0x1000) = cd[i];
else ATB(KSPACE_LOC + i % 0x1000) = 0;
}
if (spawn_thread(proc, (int (*)())USPACE_BOT) == NULL) {
free_kobj(proc);
free_pages(pbase, pgs, PHYS_PAGES);
return NULL;
}
getlock(&procthrd_lock, 0);
if (head_process == NULL) {
proc->u.proc.next = proc;
head_process = proc;
} else {
proc->u.proc.next = head_process->u.proc.next;
head_process->u.proc.next = proc;
}
unlock(&procthrd_lock, 0);
return proc;
}
void vma_freepages(vma_t *vma)
{
if (!vma)
return;
u32int i;
for (i=vma->start; i<vma->end; i+=PAGE_SIZE) {
/*printk("free_page %p\n", i);*/
INVLPG(i);
free_page( get_page(i,0,current_task->dir) );
}
}
kern_obj * spawn_thread(kern_obj * proc, int (*func)())
{
ulong fl, pg;
kern_obj * thrd = alloc_kobj();
thrd->type = KOBJ_THREAD;
thrd->u.thrd.proc = proc;
thrd->u.thrd.sub = alloc_kobj();
thrd->u.thrd.sub->type = KOBJ_THREAD_SUB;
thrd->u.thrd.sub->u.thrd2.stack_ws = alloc_ws();
pg = alloc_pages(2, PHYS_PAGES);
if (pg == 0) {
free_kobj(thrd->u.thrd.sub);
free_kobj(thrd);
return 0;
}
add_pgs_to_ws(thrd->u.thrd.sub->u.thrd2.stack_ws, USPACE_TOP - 0x2000, pg, 0x2000, 7);
thrd->u.thrd.sub->u.thrd2.rsp = USPACE_TOP - 0x50;
ATQ(KPT0_0_LOC) = (pg + 0x1000) | 3;
INVLPG(KSPACE_LOC);
ATQ(KSPACE_LOC + 0xFB0) = (ulong)func;
ATQ(KSPACE_LOC + 0xFB8) = USER_CS | 3;
GET_FLAGS(fl);
ATQ(KSPACE_LOC + 0xFC0) = fl;
ATQ(KSPACE_LOC + 0xFC8) = USPACE_TOP - 0x1000;
ATQ(KSPACE_LOC + 0xFD0) = USER_DS | 3;
getlock(&procthrd_lock, 1);
if (head_thread == NULL) {
thrd->u.thrd.next = thrd;
head_thread = thrd;
} else {
thrd->u.thrd.next = head_thread->u.thrd.next;
head_thread->u.thrd.next = thrd;
}
unlock(&procthrd_lock, 1);
return thrd;
}
void swap_ws(kern_obj * ws, int wsi)
{
kern_obj * old;
uint i;
old = cur_ws[wsi];
cur_ws[wsi] = ws;
while (old != NULL) {
for (i = 0; i < old->u.ws.size; i += 0x1000) {
set_pt_entry(old->u.ws.vbase + i, 0, old->u.ws.flags);
INVLPG(old->u.ws.vbase + i);
}
old = old->u.ws.next;
}
while (ws != NULL) {
page_in(ws->u.ws.pbase, ws->u.ws.vbase, ws->u.ws.size, ws->u.ws.flags);
ws = ws->u.ws.next;
}
}
/*
* kmem_map_page_frame(pdir, pstat, p_adr, v_adr, pages, flags)
*
* Maps an area of 'pages' page frames at address 'p_adr'
* into a virtual address space defined by the page directory
* 'pdir' to the virtual address 'v_adr'. The function will
* update the table usage statistic table 'pstat'.
*
* You can define the access flags of this pages through
* the 'flags' parameter.
*
* If a page should be mapped to an area of the virtual
* address space that currently isn't described by a
* page table, the function will automatically allocate
* and map a new page table.
*
* The function will neither free page frames, that will
* be removed from the address space nor change the
* usage counter of the selected page frames.
*
* ! If you want to map a page into the current virtual
* ! address space YOU HAVE TO use kmem_map_page_frame_cur
* ! to prevent the use of an invalid TLB content.
*
* Using the flag GENFLAG_DONT_OVERWRITE_SETTINGS will prevent
* that the function overwrites existing areas.
*
* Return Value:
* == 0 Successful
* > 0 n pages have been skipped
* < 0 Error (not enough memory to allocate a new page table)
*
*/
long kmem_map_page_frame(uint32_t *pdir,
uint32_t *pstat,
uintptr_t p_adr,
uintptr_t v_adr,
unsigned long pages,
unsigned flags
)
{
uint32_t *l__tab = NULL;
unsigned long l__lasttab = 0;
long l__retval = 0;
/* The page offset isn't interesting */
v_adr &= (~0xFFFU);
p_adr &= (~0xFFFU);
/* Change the page descriptors */
while(pages --)
{
unsigned long l__offs = (v_adr / 4096) & 0x3ff;
int l__do_invlpg = 0;
/* Is there a need of selecting a new page table ? */
if ( ((v_adr / (4096 * 1024)) != l__lasttab)
|| (l__tab == NULL)
)
{
l__tab = kmem_get_table(pdir, v_adr, true);
if (l__tab == NULL) return -1;
l__lasttab = v_adr / (4096 * 1024);
}
if ( (flags & GENFLAG_DONT_OVERWRITE_SETTINGS)
&& (l__tab[l__offs] & GENFLAG_PRESENT)
)
{
l__retval ++;
continue;
}
/* Update usage status (page descriptor used) */
if ( (flags & GENFLAG_PRESENT)
&& (v_adr < VAS_USER_END)
&& (!(l__tab[l__offs] & GENFLAG_PRESENT))
)
{
pstat[v_adr / (4096 * 1024)] ++;
}
if ( (l__tab[l__offs] & GENFLAG_PRESENT)
&& (!(flags & GENFLAG_PRESENT))
&& (v_adr < VAS_USER_END)
)
{
pstat[v_adr / (4096 * 1024)] --;
}
/* Do we need to INVLPG? */
if ((l__tab[l__offs] & GENFLAG_GLOBAL) || (flags & GENFLAG_GLOBAL)) l__do_invlpg = 1;
/* Write the page descriptor */
l__tab[l__offs] = (p_adr & (~0xFFFU))
| (flags & 0xFFFU);
/* Invalidate TLB, if needed */
if (l__do_invlpg) INVLPG(v_adr);
/* Increment the addresses */
p_adr += 4096;
v_adr += 4096;
}
return l__retval;
}
static void page_to_kpt0_0(ulong val)
{
ATQ(KPT0_0_LOC) = val;
INVLPG(KSPACE_LOC);
}
/**
* \brief Clone a page from an entry
* \param Ent Pointer to the entry in the PML4/PDP/PD/PT
* \param NextLevel Pointer to contents of the entry
* \param Addr Dest address
* \note Used in COW
*/
void MM_int_ClonePageEnt( Uint64 *Ent, void *NextLevel, tVAddr Addr, int bTable )
{
tPAddr curpage = *Ent & PADDR_MASK;
int bCopied = 0;
if( MM_GetRefCount( curpage ) <= 0 ) {
Log_KernelPanic("MMVirt", "Page %P still marked COW, but unreferenced", curpage);
}
if( MM_GetRefCount( curpage ) == 1 )
{
*Ent &= ~PF_COW;
*Ent |= PF_PRESENT|PF_WRITE;
#if TRACE_COW
Log_Debug("MMVirt", "COW ent at %p (%p) only %P", Ent, NextLevel, curpage);
#endif
}
else
{
void *tmp;
tPAddr paddr;
if( !(paddr = MM_AllocPhys()) ) {
Threads_SegFault(Addr);
return ;
}
ASSERT(paddr != curpage);
tmp = MM_MapTemp(paddr);
memcpy( tmp, NextLevel, 0x1000 );
MM_FreeTemp( tmp );
#if TRACE_COW
Log_Debug("MMVirt", "COW ent at %p (%p) from %P to %P", Ent, NextLevel, curpage, paddr);
#endif
MM_DerefPhys( curpage );
*Ent &= PF_USER;
*Ent |= paddr|PF_PRESENT|PF_WRITE;
bCopied = 1;
}
INVLPG( (tVAddr)NextLevel );
// Mark COW on contents if it's a PDPT, Dir or Table
if(bTable)
{
Uint64 *dp = NextLevel;
int i;
for( i = 0; i < 512; i ++ )
{
if( !(dp[i] & PF_PRESENT) )
continue;
if( bCopied )
MM_RefPhys( dp[i] & PADDR_MASK );
if( dp[i] & PF_WRITE ) {
dp[i] &= ~PF_WRITE;
dp[i] |= PF_COW;
}
}
}
}
