/*===========================================================================*
* pt_writemap *
*===========================================================================*/
int pt_writemap(struct vmproc * vmp,
pt_t *pt,
vir_bytes v,
phys_bytes physaddr,
size_t bytes,
u32_t flags,
u32_t writemapflags)
{
/* Write mapping into page table. Allocate a new page table if necessary. */
/* Page directory and table entries for this virtual address. */
int p, pages;
int verify = 0;
int ret = OK;
#ifdef CONFIG_SMP
int vminhibit_clear = 0;
/* FIXME
* don't do it everytime, stop the process only on the first change and
* resume the execution on the last change. Do in a wrapper of this
* function
*/
if (vmp && vmp->vm_endpoint != NONE && vmp->vm_endpoint != VM_PROC_NR &&
!(vmp->vm_flags & VMF_EXITING)) {
sys_vmctl(vmp->vm_endpoint, VMCTL_VMINHIBIT_SET, 0);
vminhibit_clear = 1;
}
#endif
if(writemapflags & WMF_VERIFY)
verify = 1;
assert(!(bytes % VM_PAGE_SIZE));
assert(!(flags & ~(PTF_ALLFLAGS)));
pages = bytes / VM_PAGE_SIZE;
/* MAP_NONE means to clear the mapping. It doesn't matter
* what's actually written into the PTE if PRESENT
* isn't on, so we can just write MAP_NONE into it.
*/
assert(physaddr == MAP_NONE || (flags & ARCH_VM_PTE_PRESENT));
assert(physaddr != MAP_NONE || !flags);
/* First make sure all the necessary page tables are allocated,
* before we start writing in any of them, because it's a pain
* to undo our work properly.
*/
ret = pt_ptalloc_in_range(pt, v, v + VM_PAGE_SIZE*pages, flags, verify);
if(ret != OK) {
printf("VM: writemap: pt_ptalloc_in_range failed\n");
goto resume_exit;
}
/* Now write in them. */
for(p = 0; p < pages; p++) {
u32_t entry;
int pde = ARCH_VM_PDE(v);
int pte = ARCH_VM_PTE(v);
assert(!(v % VM_PAGE_SIZE));
assert(pte >= 0 && pte < ARCH_VM_PT_ENTRIES);
assert(pde >= 0 && pde < ARCH_VM_DIR_ENTRIES);
/* Page table has to be there. */
assert(pt->pt_dir[pde] & ARCH_VM_PDE_PRESENT);
/* We do not expect it to be a bigpage. */
assert(!(pt->pt_dir[pde] & ARCH_VM_BIGPAGE));
/* Make sure page directory entry for this page table
* is marked present and page table entry is available.
*/
assert(pt->pt_pt[pde]);
#if SANITYCHECKS
/* We don't expect to overwrite a page. */
if(!(writemapflags & (WMF_OVERWRITE|WMF_VERIFY)))
assert(!(pt->pt_pt[pde][pte] & ARCH_VM_PTE_PRESENT));
#endif
if(writemapflags & (WMF_WRITEFLAGSONLY|WMF_FREE)) {
#if defined(__i386__)
physaddr = pt->pt_pt[pde][pte] & ARCH_VM_ADDR_MASK;
#elif defined(__arm__)
physaddr = pt->pt_pt[pde][pte] & ARM_VM_PTE_MASK;
#endif
}
if(writemapflags & WMF_FREE) {
free_mem(ABS2CLICK(physaddr), 1);
}
/* Entry we will write. */
#if defined(__i386__)
entry = (physaddr & ARCH_VM_ADDR_MASK) | flags;
#elif defined(__arm__)
entry = (physaddr & ARM_VM_PTE_MASK) | flags;
#endif
if(verify) {
u32_t maskedentry;
maskedentry = pt->pt_pt[pde][pte];
#if defined(__i386__)
maskedentry &= ~(I386_VM_ACC|I386_VM_DIRTY);
#endif
/* Verify pagetable entry. */
#if defined(__i386__)
if(entry & ARCH_VM_PTE_RW) {
/* If we expect a writable page, allow a readonly page. */
maskedentry |= ARCH_VM_PTE_RW;
}
#elif defined(__arm__)
if(!(entry & ARCH_VM_PTE_RO)) {
/* If we expect a writable page, allow a readonly page. */
maskedentry &= ~ARCH_VM_PTE_RO;
}
maskedentry &= ~(ARM_VM_PTE_WB|ARM_VM_PTE_WT);
#endif
if(maskedentry != entry) {
printf("pt_writemap: mismatch: ");
#if defined(__i386__)
if((entry & ARCH_VM_ADDR_MASK) !=
(maskedentry & ARCH_VM_ADDR_MASK)) {
#elif defined(__arm__)
if((entry & ARM_VM_PTE_MASK) !=
(maskedentry & ARM_VM_PTE_MASK)) {
#endif
printf("pt_writemap: physaddr mismatch (0x%lx, 0x%lx); ",
(long)entry, (long)maskedentry);
} else printf("phys ok; ");
printf(" flags: found %s; ",
ptestr(pt->pt_pt[pde][pte]));
printf(" masked %s; ",
ptestr(maskedentry));
printf(" expected %s\n", ptestr(entry));
printf("found 0x%x, wanted 0x%x\n",
pt->pt_pt[pde][pte], entry);
ret = EFAULT;
goto resume_exit;
}
} else {
/* Write pagetable entry. */
pt->pt_pt[pde][pte] = entry;
}
physaddr += VM_PAGE_SIZE;
v += VM_PAGE_SIZE;
}
resume_exit:
#ifdef CONFIG_SMP
if (vminhibit_clear) {
assert(vmp && vmp->vm_endpoint != NONE && vmp->vm_endpoint != VM_PROC_NR &&
!(vmp->vm_flags & VMF_EXITING));
sys_vmctl(vmp->vm_endpoint, VMCTL_VMINHIBIT_CLEAR, 0);
}
#endif
return ret;
}
/*===========================================================================*
* pt_checkrange *
*===========================================================================*/
int pt_checkrange(pt_t *pt, vir_bytes v, size_t bytes,
int write)
{
int p, pages;
assert(!(bytes % VM_PAGE_SIZE));
pages = bytes / VM_PAGE_SIZE;
for(p = 0; p < pages; p++) {
int pde = ARCH_VM_PDE(v);
int pte = ARCH_VM_PTE(v);
assert(!(v % VM_PAGE_SIZE));
assert(pte >= 0 && pte < ARCH_VM_PT_ENTRIES);
assert(pde >= 0 && pde < ARCH_VM_DIR_ENTRIES);
/* Page table has to be there. */
if(!(pt->pt_dir[pde] & ARCH_VM_PDE_PRESENT))
return EFAULT;
/* Make sure page directory entry for this page table
* is marked present and page table entry is available.
*/
assert((pt->pt_dir[pde] & ARCH_VM_PDE_PRESENT) && pt->pt_pt[pde]);
if(!(pt->pt_pt[pde][pte] & ARCH_VM_PTE_PRESENT)) {
return EFAULT;
}
#if defined(__i386__)
if(write && !(pt->pt_pt[pde][pte] & ARCH_VM_PTE_RW)) {
#elif defined(__arm__)
if(write && (pt->pt_pt[pde][pte] & ARCH_VM_PTE_RO)) {
#endif
return EFAULT;
}
v += VM_PAGE_SIZE;
}
return OK;
}
/*===========================================================================*
* pt_new *
*===========================================================================*/
int pt_new(pt_t *pt)
{
/* Allocate a pagetable root. Allocate a page-aligned page directory
* and set them to 0 (indicating no page tables are allocated). Lookup
* its physical address as we'll need that in the future. Verify it's
* page-aligned.
*/
int i, r;
/* Don't ever re-allocate/re-move a certain process slot's
* page directory once it's been created. This is a fraction
* faster, but also avoids having to invalidate the page
* mappings from in-kernel page tables pointing to
* the page directories (the page_directories data).
*/
if(!pt->pt_dir &&
!(pt->pt_dir = vm_allocpages((phys_bytes *)&pt->pt_dir_phys,
VMP_PAGEDIR, ARCH_PAGEDIR_SIZE/VM_PAGE_SIZE))) {
return ENOMEM;
}
assert(!((u32_t)pt->pt_dir_phys % ARCH_PAGEDIR_SIZE));
for(i = 0; i < ARCH_VM_DIR_ENTRIES; i++) {
pt->pt_dir[i] = 0; /* invalid entry (PRESENT bit = 0) */
pt->pt_pt[i] = NULL;
}
/* Where to start looking for free virtual address space? */
pt->pt_virtop = 0;
/* Map in kernel. */
if((r=pt_mapkernel(pt)) != OK)
return r;
return OK;
}
/*===========================================================================*
* pt_writemap *
*===========================================================================*/
PUBLIC int pt_writemap(struct vmproc * vmp,
pt_t *pt,
vir_bytes v,
phys_bytes physaddr,
size_t bytes,
u32_t flags,
u32_t writemapflags)
{
/* Write mapping into page table. Allocate a new page table if necessary. */
/* Page directory and table entries for this virtual address. */
int p, r, pages;
int verify = 0;
int ret = OK;
/* FIXME
* don't do it everytime, stop the process only on the first change and
* resume the execution on the last change. Do in a wrapper of this
* function
*/
if (vmp && vmp->vm_endpoint != NONE && vmp->vm_endpoint != VM_PROC_NR &&
!(vmp->vm_flags & VMF_EXITING))
sys_vmctl(vmp->vm_endpoint, VMCTL_VMINHIBIT_SET, 0);
if(writemapflags & WMF_VERIFY)
verify = 1;
assert(!(bytes % I386_PAGE_SIZE));
assert(!(flags & ~(PTF_ALLFLAGS)));
pages = bytes / I386_PAGE_SIZE;
/* MAP_NONE means to clear the mapping. It doesn't matter
* what's actually written into the PTE if I386_VM_PRESENT
* isn't on, so we can just write MAP_NONE into it.
*/
assert(physaddr == MAP_NONE || (flags & I386_VM_PRESENT));
assert(physaddr != MAP_NONE || !flags);
/* First make sure all the necessary page tables are allocated,
* before we start writing in any of them, because it's a pain
* to undo our work properly.
*/
ret = pt_ptalloc_in_range(pt, v, v + I386_PAGE_SIZE*pages, flags, verify);
if(ret != OK) {
goto resume_exit;
}
/* Now write in them. */
for(p = 0; p < pages; p++) {
u32_t entry;
int pde = I386_VM_PDE(v);
int pte = I386_VM_PTE(v);
assert(!(v % I386_PAGE_SIZE));
assert(pte >= 0 && pte < I386_VM_PT_ENTRIES);
assert(pde >= 0 && pde < I386_VM_DIR_ENTRIES);
/* Page table has to be there. */
assert(pt->pt_dir[pde] & I386_VM_PRESENT);
/* Make sure page directory entry for this page table
* is marked present and page table entry is available.
*/
assert((pt->pt_dir[pde] & I386_VM_PRESENT));
assert(pt->pt_pt[pde]);
#if SANITYCHECKS
/* We don't expect to overwrite a page. */
if(!(writemapflags & (WMF_OVERWRITE|WMF_VERIFY)))
assert(!(pt->pt_pt[pde][pte] & I386_VM_PRESENT));
#endif
if(writemapflags & (WMF_WRITEFLAGSONLY|WMF_FREE)) {
physaddr = pt->pt_pt[pde][pte] & I386_VM_ADDR_MASK;
}
if(writemapflags & WMF_FREE) {
free_mem(ABS2CLICK(physaddr), 1);
}
/* Entry we will write. */
entry = (physaddr & I386_VM_ADDR_MASK) | flags;
if(verify) {
u32_t maskedentry;
maskedentry = pt->pt_pt[pde][pte];
maskedentry &= ~(I386_VM_ACC|I386_VM_DIRTY);
/* Verify pagetable entry. */
if(entry & I386_VM_WRITE) {
/* If we expect a writable page, allow a readonly page. */
maskedentry |= I386_VM_WRITE;
}
if(maskedentry != entry) {
printf("pt_writemap: mismatch: ");
if((entry & I386_VM_ADDR_MASK) !=
(maskedentry & I386_VM_ADDR_MASK)) {
printf("pt_writemap: physaddr mismatch (0x%lx, 0x%lx); ", entry, maskedentry);
} else printf("phys ok; ");
printf(" flags: found %s; ",
ptestr(pt->pt_pt[pde][pte]));
printf(" masked %s; ",
ptestr(maskedentry));
printf(" expected %s\n", ptestr(entry));
ret = EFAULT;
goto resume_exit;
}
} else {
/* Write pagetable entry. */
#if SANITYCHECKS
assert(vm_addrok(pt->pt_pt[pde], 1));
#endif
pt->pt_pt[pde][pte] = entry;
}
physaddr += I386_PAGE_SIZE;
v += I386_PAGE_SIZE;
}
resume_exit:
if (vmp && vmp->vm_endpoint != NONE && vmp->vm_endpoint != VM_PROC_NR &&
!(vmp->vm_flags & VMF_EXITING))
sys_vmctl(vmp->vm_endpoint, VMCTL_VMINHIBIT_CLEAR, 0);
return ret;
}
