/*
* Reallocate the maps for a process
*
* Subtlety: On a 32K box we have the udata area being copied to/from
* the stash. As we always realloc for the live process we don't have
* to worry about this in the 32K + common case because we'll switchin
* at one size, and switchout at the other and the udata will just get
* saved/restored to the right places.
*/
int pagemap_realloc(uint16_t size) {
int have = maps_needed(udata.u_top);
int want = maps_needed(size);
uint8_t *ptr = (uint8_t *) & udata.u_page;
/* If we are shrinking then free pages and propogate the
common page into the freed spaces */
if (want == have)
return 0;
if (have > want) {
pfree[pfptr++] = ptr[1];
udata.u_ptab->p_page = udata.u_page;
return 0;
}
/* If we are adding then just insert the new pages, keeping the common
unchanged at the top */
if (want - have > pfptr)
return ENOMEM;
/* We don't want to take an interrupt here while our page mappings are
incomplete. We may restore bogus mappings and then take a second IRQ
into hyperspace */
__critical {
ptr[0] = pfree[--pfptr];
/* Copy the updated allocation into the ptab */
udata.u_ptab->p_page = udata.u_page;
/* Now fix the vectors up - they've potentially teleported up to 32K up
the user address space, we need to put a copy back in low memory before
we switch to this memory map */
program_vectors(&udata.u_page);
}
return 0;
}
/*
* Reallocate the maps for a process
*/
int pagemap_realloc(usize_t size)
{
int8_t have = maps_needed(udata.u_top);
int8_t want = maps_needed(size);
uint8_t *ptr = (uint8_t *) & udata.u_page;
int8_t i;
uint8_t update = 0;
irqflags_t irq;
/* If we are shrinking then free pages and propogate the
common page into the freed spaces */
if (want == have)
return 0;
/* We don't want to take an interrupt here while our page mappings are
incomplete. We may restore bogus mappings and then take a second IRQ
into hyperspace */
irq = di();
if (have > want) {
for (i = want; i < have; i++) {
pfree[pfptr++] = ptr[i - 1];
ptr[i - 1] = ptr[3];
}
/* We collapsed top and bottom, so we need to sort our vectors
and common space out */
if (want == 1)
update = 1;
} else if (want - have <= pfptr) {
/* If we are adding then just insert the new pages, keeping the common
unchanged at the top */
for (i = have; i < want; i++)
ptr[i - 1] = pfree[--pfptr];
update = 1;
} else {
irqrestore(irq);
return ENOMEM;
}
/* Copy the updated allocation into the ptab */
udata.u_ptab->p_page = udata.u_page;
udata.u_ptab->p_page2 = udata.u_page2;
/* Now fix the vectors up - they've potentially teleported up to 48K up
the user address space, we need to put a copy back in low memory before
we switch to this memory map */
if (update)
program_vectors(&udata.u_page);
irqrestore(irq);
return 0;
}
/*
* Allocate the maps for this task post fork
* We have a hackish fix for init that would be nice
* resolve.
*
* FIXME: we need to move udata.u_top into p-> in order to
* support banked swapping.
*/
int pagemap_alloc(ptptr p)
{
uint8_t *ptr = (uint8_t *) & p->p_page;
int needed = maps_needed(udata.u_top);
int i;
#ifdef SWAPDEV
/* Throw our toys out of our pram until we have enough room */
while (needed > pfptr)
if (swapneeded(p, 1) == NULL)
return ENOMEM;
#else
if (needed > pfptr) /* We have no swap so poof... */
return ENOMEM;
#endif
/* Pages in the low then repeat the top one */
for (i = 0; i < needed; i++)
ptr[i] = pfree[--pfptr];
while (i < 4) {
ptr[i] = ptr[i - 1];
i++;
}
return 0;
}
/*
* Reallocate the maps for a process
*/
int pagemap_realloc(uint16_t size)
{
int have = maps_needed(udata.u_top);
int want = maps_needed(size);
uint8_t *ptr = (uint8_t *) & udata.u_page;
int i;
irqflags_t irq;
/* If we are shrinking then free pages and propogate the
common page into the freed spaces */
if (want == have)
return 0;
if (have > want) {
for (i = want; i < have; i++) {
pfree[pfptr++] = ptr[i];
ptr[i] = ptr[3];
}
udata.u_ptab->p_page = udata.u_page;
udata.u_ptab->p_page2 = udata.u_page2;
return 0;
}
/* If we are adding then just insert the new pages, keeping the common
unchanged at the top */
if (want - have > pfptr)
return ENOMEM;
/* We have common low so we must only touch the higher pages. This is
different from the high common case */
for (i = have; i < want; i++)
ptr[i] = pfree[--pfptr];
while(i < 4) {
ptr[i] = ptr[i-1];
i++;
}
/* Copy the updated allocation into the ptab */
udata.u_ptab->p_page = udata.u_page;
udata.u_ptab->p_page2 = udata.u_page2;
return 0;
}
/*
* Allocate the maps for this task post fork
* We have a hackish fix for init that would be nice
* resolve.
*/
int pagemap_alloc(ptptr p)
{
uint8_t *ptr = (uint8_t *) & p->p_page;
int needed = maps_needed(udata.u_top);
#ifdef SWAPDEV
/* Throw our toys out of our pram until we have enough room */
while (needed > pfptr)
if (swapneeded(p, 1) == NULL)
return ENOMEM;
#else
if (needed > pfptr) /* We have no swap so poof... */
return ENOMEM;
#endif
*ptr = pfree[--pfptr];
if (needed == 1)
ptr[1] = *ptr;
else
ptr[1] = pfree[--pfptr];
return 0;
}
