/*===========================================================================*
* vm_freepages *
*===========================================================================*/
void vm_freepages(vir_bytes vir, int pages)
{
assert(!(vir % VM_PAGE_SIZE));
if(is_staticaddr(vir)) {
printf("VM: not freeing static page\n");
return;
}
if(pt_writemap(vmprocess, &vmprocess->vm_pt, vir,
MAP_NONE, pages*VM_PAGE_SIZE, 0,
WMF_OVERWRITE | WMF_FREE) != OK)
panic("vm_freepages: pt_writemap failed");
vm_self_pages--;
#if SANITYCHECKS
/* If SANITYCHECKS are on, flush tlb so accessing freed pages is
* always trapped, also if not in tlb.
*/
if((sys_vmctl(SELF, VMCTL_FLUSHTLB, 0)) != OK) {
panic("VMCTL_FLUSHTLB failed");
}
#endif
}
/*===========================================================================*
* vm_allocpage *
*===========================================================================*/
void *vm_allocpages(phys_bytes *phys, int reason, int pages)
{
/* Allocate a page for use by VM itself. */
phys_bytes newpage;
static int level = 0;
void *ret;
u32_t mem_flags = 0;
assert(reason >= 0 && reason < VMP_CATEGORIES);
assert(pages > 0);
level++;
assert(level >= 1);
assert(level <= 2);
if((level > 1) || !pt_init_done) {
void *s;
if(pages == 1) s=vm_getsparepage(phys);
else if(pages == 4) s=vm_getsparepagedir(phys);
else panic("%d pages", pages);
level--;
if(!s) {
util_stacktrace();
printf("VM: warning: out of spare pages\n");
}
if(!is_staticaddr(s)) vm_self_pages++;
return s;
}
#if defined(__arm__)
if (reason == VMP_PAGEDIR) {
mem_flags |= PAF_ALIGN16K;
}
#endif
/* Allocate page of memory for use by VM. As VM
* is trusted, we don't have to pre-clear it.
*/
if((newpage = alloc_mem(pages, mem_flags)) == NO_MEM) {
level--;
printf("VM: vm_allocpage: alloc_mem failed\n");
return NULL;
}
*phys = CLICK2ABS(newpage);
if(!(ret = vm_mappages(*phys, pages))) {
level--;
printf("VM: vm_allocpage: vm_mappages failed\n");
return NULL;
}
level--;
vm_self_pages++;
return ret;
}
/*===========================================================================*
* vm_allocpage *
*===========================================================================*/
void *vm_allocpages(phys_bytes *phys, int reason, int pages)
{
/* Allocate a page for use by VM itself. */
phys_bytes newpage;
vir_bytes loc;
pt_t *pt;
int r;
static int level = 0;
void *ret;
u32_t mem_flags = 0;
pt = &vmprocess->vm_pt;
assert(reason >= 0 && reason < VMP_CATEGORIES);
assert(pages > 0);
level++;
assert(level >= 1);
assert(level <= 2);
if((level > 1) || !pt_init_done) {
void *s;
if(pages == 1) s=vm_getsparepage(phys);
else if(pages == 4) s=vm_getsparepagedir(phys);
else panic("%d pages", pages);
level--;
if(!s) {
util_stacktrace();
printf("VM: warning: out of spare pages\n");
}
if(!is_staticaddr(s)) vm_self_pages++;
return s;
}
#if defined(__arm__)
if (reason == VMP_PAGEDIR) {
mem_flags |= PAF_ALIGN16K;
}
#endif
/* VM does have a pagetable, so get a page and map it in there.
* Where in our virtual address space can we put it?
*/
loc = findhole(pages);
if(loc == NO_MEM) {
level--;
printf("VM: vm_allocpage: findhole failed\n");
return NULL;
}
/* Allocate page of memory for use by VM. As VM
* is trusted, we don't have to pre-clear it.
*/
if((newpage = alloc_mem(pages, mem_flags)) == NO_MEM) {
level--;
printf("VM: vm_allocpage: alloc_mem failed\n");
return NULL;
}
*phys = CLICK2ABS(newpage);
/* Map this page into our address space. */
if((r=pt_writemap(vmprocess, pt, loc, *phys, VM_PAGE_SIZE*pages,
ARCH_VM_PTE_PRESENT | ARCH_VM_PTE_USER | ARCH_VM_PTE_RW
#if defined(__arm__)
| ARM_VM_PTE_WB | ARM_VM_PTE_SHAREABLE
#endif
, 0)) != OK) {
free_mem(newpage, pages);
printf("vm_allocpage writemap failed\n");
level--;
return NULL;
}
if((r=sys_vmctl(SELF, VMCTL_FLUSHTLB, 0)) != OK) {
panic("VMCTL_FLUSHTLB failed: %d", r);
}
level--;
/* Return user-space-ready pointer to it. */
ret = (void *) loc;
vm_self_pages++;
return ret;
}
/*===========================================================================*
* findhole *
*===========================================================================*/
static u32_t findhole(int pages)
{
/* Find a space in the virtual address space of VM. */
u32_t curv;
int pde = 0, try_restart;
static u32_t lastv = 0;
pt_t *pt = &vmprocess->vm_pt;
vir_bytes vmin, vmax;
#if defined(__arm__)
u32_t holev;
#endif
vmin = (vir_bytes) (&_end); /* marks end of VM BSS */
vmin += 1024*1024*1024; /* reserve 1GB virtual address space for VM heap */
vmin &= ARCH_VM_ADDR_MASK;
vmax = VM_STACKTOP;
/* Input sanity check. */
assert(vmin + VM_PAGE_SIZE >= vmin);
assert(vmax >= vmin + VM_PAGE_SIZE);
assert((vmin % VM_PAGE_SIZE) == 0);
assert((vmax % VM_PAGE_SIZE) == 0);
#if defined(__arm__)
assert(pages > 0);
#endif
#if SANITYCHECKS
curv = ((u32_t) random()) % ((vmax - vmin)/VM_PAGE_SIZE);
curv *= VM_PAGE_SIZE;
curv += vmin;
#else
curv = lastv;
if(curv < vmin || curv >= vmax)
curv = vmin;
#endif
try_restart = 1;
/* Start looking for a free page starting at vmin. */
while(curv < vmax) {
int pte;
#if defined(__arm__)
int i, nohole;
#endif
assert(curv >= vmin);
assert(curv < vmax);
#if defined(__i386__)
pde = I386_VM_PDE(curv);
pte = I386_VM_PTE(curv);
#elif defined(__arm__)
holev = curv; /* the candidate hole */
nohole = 0;
for (i = 0; i < pages && !nohole; ++i) {
if(curv >= vmax) {
break;
}
#endif
#if defined(__i386__)
if(!(pt->pt_dir[pde] & ARCH_VM_PDE_PRESENT) ||
!(pt->pt_pt[pde][pte] & ARCH_VM_PAGE_PRESENT)) {
#elif defined(__arm__)
pde = ARM_VM_PDE(curv);
pte = ARM_VM_PTE(curv);
/* if page present, no hole */
if((pt->pt_dir[pde] & ARCH_VM_PDE_PRESENT) &&
(pt->pt_pt[pde][pte] & ARCH_VM_PTE_PRESENT))
nohole = 1;
/* if not contiguous, no hole */
if (curv != holev + i * VM_PAGE_SIZE)
nohole = 1;
curv+=VM_PAGE_SIZE;
}
/* there's a large enough hole */
if (!nohole && i == pages) {
#endif
lastv = curv;
#if defined(__i386__)
return curv;
#elif defined(__arm__)
return holev;
#endif
}
#if defined(__i386__)
curv+=VM_PAGE_SIZE;
#elif defined(__arm__)
/* Reset curv */
#endif
if(curv >= vmax && try_restart) {
curv = vmin;
try_restart = 0;
}
}
printf("VM: out of virtual address space in vm\n");
return NO_MEM;
}
/*===========================================================================*
* vm_freepages *
*===========================================================================*/
void vm_freepages(vir_bytes vir, int pages)
{
assert(!(vir % VM_PAGE_SIZE));
if(is_staticaddr(vir)) {
printf("VM: not freeing static page\n");
return;
}
if(pt_writemap(vmprocess, &vmprocess->vm_pt, vir,
MAP_NONE, pages*VM_PAGE_SIZE, 0,
WMF_OVERWRITE | WMF_FREE) != OK)
panic("vm_freepages: pt_writemap failed");
vm_self_pages--;
#if SANITYCHECKS
/* If SANITYCHECKS are on, flush tlb so accessing freed pages is
* always trapped, also if not in tlb.
*/
if((sys_vmctl(SELF, VMCTL_FLUSHTLB, 0)) != OK) {
panic("VMCTL_FLUSHTLB failed");
}
#endif
}
