966 lines
28 KiB
C
966 lines
28 KiB
C
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#define _SYSTEM 1
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#define _POSIX_SOURCE 1
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#include <minix/callnr.h>
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#include <minix/com.h>
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#include <minix/config.h>
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#include <minix/const.h>
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#include <minix/ds.h>
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#include <minix/endpoint.h>
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#include <minix/keymap.h>
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#include <minix/minlib.h>
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#include <minix/type.h>
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#include <minix/ipc.h>
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#include <minix/sysutil.h>
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#include <minix/syslib.h>
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#include <minix/safecopies.h>
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#include <minix/cpufeature.h>
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#include <minix/bitmap.h>
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#include <errno.h>
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#include <stdlib.h>
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#include <assert.h>
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#include <string.h>
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#include <env.h>
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#include <stdio.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#include "../proto.h"
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#include "../glo.h"
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#include "../util.h"
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#include "../vm.h"
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#include "../sanitycheck.h"
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#include "memory.h"
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/* PDE used to map in kernel, kernel physical address. */
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PRIVATE int id_map_high_pde = -1, pagedir_pde = -1;
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PRIVATE u32_t global_bit = 0, pagedir_pde_val;
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PRIVATE int proc_pde = 0;
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/* 4MB page size available in hardware? */
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PRIVATE int bigpage_ok = 0;
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/* Our process table entry. */
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struct vmproc *vmp = &vmproc[VM_PROC_NR];
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/* Spare memory, ready to go after initialization, to avoid a
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* circular dependency on allocating memory and writing it into VM's
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* page table.
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*/
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#define SPAREPAGES 25
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int missing_spares = SPAREPAGES;
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PRIVATE struct {
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void *page;
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u32_t phys;
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} sparepages[SPAREPAGES];
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#define MAX_KERNMAPPINGS 10
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PRIVATE struct {
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phys_bytes phys_addr; /* Physical addr. */
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phys_bytes len; /* Length in bytes. */
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vir_bytes lin_addr; /* Offset in page table. */
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int flags;
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} kern_mappings[MAX_KERNMAPPINGS];
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int kernmappings = 0;
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/* Clicks must be pages, as
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* - they must be page aligned to map them
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* - they must be a multiple of the page size
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* - it's inconvenient to have them bigger than pages, because we often want
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* just one page
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* May as well require them to be equal then.
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*/
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#if CLICK_SIZE != I386_PAGE_SIZE
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#error CLICK_SIZE must be page size.
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#endif
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/* Bytes of virtual address space one pde controls. */
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#define BYTESPERPDE (I386_VM_PT_ENTRIES * I386_PAGE_SIZE)
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/* Nevertheless, introduce these macros to make the code readable. */
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#define CLICK2PAGE(c) ((c) / CLICKSPERPAGE)
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/* Page table that contains pointers to all page directories. */
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u32_t page_directories_phys, *page_directories = NULL;
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#if SANITYCHECKS
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/*===========================================================================*
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* pt_sanitycheck *
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*===========================================================================*/
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PUBLIC void pt_sanitycheck(pt_t *pt, char *file, int line)
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{
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/* Basic pt sanity check. */
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int i;
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int slot;
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MYASSERT(pt);
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MYASSERT(pt->pt_dir);
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MYASSERT(pt->pt_dir_phys);
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for(slot = 0; slot < ELEMENTS(vmproc); slot++) {
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if(pt == &vmproc[slot].vm_pt)
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break;
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}
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if(slot >= ELEMENTS(vmproc)) {
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vm_panic("pt_sanitycheck: passed pt not in any proc", NO_NUM);
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}
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MYASSERT(usedpages_add(pt->pt_dir_phys, I386_PAGE_SIZE) == OK);
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for(i = proc_pde; i < I386_VM_DIR_ENTRIES; i++) {
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if(pt->pt_pt[i]) {
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if(!(pt->pt_dir[i] & I386_VM_PRESENT)) {
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printf("slot %d: pt->pt_pt[%d] = 0x%lx, but pt_dir entry 0x%lx\n",
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slot, i, pt->pt_pt[i], pt->pt_dir[i]);
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}
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MYASSERT(pt->pt_dir[i] & I386_VM_PRESENT);
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MYASSERT(usedpages_add(I386_VM_PFA(pt->pt_dir[i]),
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I386_PAGE_SIZE) == OK);
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} else {
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MYASSERT(!(pt->pt_dir[i] & I386_VM_PRESENT));
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}
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}
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}
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#endif
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/*===========================================================================*
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* aalloc *
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*===========================================================================*/
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PRIVATE void *aalloc(size_t bytes)
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{
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/* Page-aligned malloc(). only used if vm_allocpage can't be used. */
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u32_t b;
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b = (u32_t) malloc(I386_PAGE_SIZE + bytes);
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if(!b) vm_panic("aalloc: out of memory", bytes);
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b += I386_PAGE_SIZE - (b % I386_PAGE_SIZE);
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return (void *) b;
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}
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/*===========================================================================*
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* findhole *
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*===========================================================================*/
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PRIVATE u32_t findhole(pt_t *pt, u32_t vmin, u32_t vmax)
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{
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/* Find a space in the virtual address space of pageteble 'pt',
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* between page-aligned BYTE offsets vmin and vmax, to fit
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* a page in. Return byte offset.
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*/
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u32_t freefound = 0, curv;
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int pde = 0, try_restart;
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static u32_t lastv = 0;
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/* Input sanity check. */
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vm_assert(vmin + I386_PAGE_SIZE >= vmin);
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vm_assert(vmax >= vmin + I386_PAGE_SIZE);
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vm_assert((vmin % I386_PAGE_SIZE) == 0);
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vm_assert((vmax % I386_PAGE_SIZE) == 0);
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#if SANITYCHECKS
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curv = ((u32_t) random()) % ((vmax - vmin)/I386_PAGE_SIZE);
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curv *= I386_PAGE_SIZE;
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curv += vmin;
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#else
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curv = lastv;
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if(curv < vmin || curv >= vmax)
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curv = vmin;
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#endif
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try_restart = 1;
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/* Start looking for a free page starting at vmin. */
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while(curv < vmax) {
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int pte;
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vm_assert(curv >= vmin);
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vm_assert(curv < vmax);
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pde = I386_VM_PDE(curv);
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pte = I386_VM_PTE(curv);
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if(!(pt->pt_dir[pde] & I386_VM_PRESENT) ||
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!(pt->pt_pt[pde][pte] & I386_VM_PRESENT)) {
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lastv = curv;
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return curv;
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}
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curv+=I386_PAGE_SIZE;
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if(curv >= vmax && try_restart) {
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curv = vmin;
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try_restart = 0;
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}
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}
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printf("VM: out of virtual address space in vm\n");
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return NO_MEM;
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}
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/*===========================================================================*
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* vm_freepages *
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*===========================================================================*/
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PRIVATE void vm_freepages(vir_bytes vir, vir_bytes phys, int pages, int reason)
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{
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vm_assert(reason >= 0 && reason < VMP_CATEGORIES);
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if(vir >= vmp->vm_stacktop) {
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vm_assert(!(vir % I386_PAGE_SIZE));
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vm_assert(!(phys % I386_PAGE_SIZE));
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FREE_MEM(ABS2CLICK(phys), pages);
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if(pt_writemap(&vmp->vm_pt, arch_vir2map(vmp, vir),
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MAP_NONE, pages*I386_PAGE_SIZE, 0, WMF_OVERWRITE) != OK)
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vm_panic("vm_freepages: pt_writemap failed",
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NO_NUM);
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} else {
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printf("VM: vm_freepages not freeing VM heap pages (%d)\n",
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pages);
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}
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}
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/*===========================================================================*
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* vm_getsparepage *
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*===========================================================================*/
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PRIVATE void *vm_getsparepage(u32_t *phys)
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{
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int s;
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vm_assert(missing_spares >= 0 && missing_spares <= SPAREPAGES);
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for(s = 0; s < SPAREPAGES; s++) {
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if(sparepages[s].page) {
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void *sp;
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sp = sparepages[s].page;
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*phys = sparepages[s].phys;
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sparepages[s].page = NULL;
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missing_spares++;
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vm_assert(missing_spares >= 0 && missing_spares <= SPAREPAGES);
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return sp;
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}
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}
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return NULL;
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}
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/*===========================================================================*
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* vm_checkspares *
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*===========================================================================*/
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PRIVATE void *vm_checkspares(void)
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{
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int s, n = 0;
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static int total = 0, worst = 0;
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vm_assert(missing_spares >= 0 && missing_spares <= SPAREPAGES);
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for(s = 0; s < SPAREPAGES && missing_spares > 0; s++)
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if(!sparepages[s].page) {
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n++;
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if((sparepages[s].page = vm_allocpage(&sparepages[s].phys,
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VMP_SPARE))) {
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missing_spares--;
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vm_assert(missing_spares >= 0);
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vm_assert(missing_spares <= SPAREPAGES);
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} else {
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printf("VM: warning: couldn't get new spare page\n");
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}
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}
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if(worst < n) worst = n;
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total += n;
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return NULL;
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}
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/*===========================================================================*
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* vm_allocpage *
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*===========================================================================*/
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PUBLIC void *vm_allocpage(phys_bytes *phys, int reason)
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{
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/* Allocate a page for use by VM itself. */
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phys_bytes newpage;
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vir_bytes loc;
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pt_t *pt;
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int r;
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static int level = 0;
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void *ret;
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pt = &vmp->vm_pt;
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vm_assert(reason >= 0 && reason < VMP_CATEGORIES);
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level++;
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vm_assert(level >= 1);
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vm_assert(level <= 2);
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if(level > 1 || !(vmp->vm_flags & VMF_HASPT) || !meminit_done) {
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int r;
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void *s;
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s=vm_getsparepage(phys);
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level--;
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if(!s) {
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util_stacktrace();
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printf("VM: warning: out of spare pages\n");
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}
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return s;
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}
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/* VM does have a pagetable, so get a page and map it in there.
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* Where in our virtual address space can we put it?
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*/
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loc = findhole(pt, arch_vir2map(vmp, vmp->vm_stacktop),
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vmp->vm_arch.vm_data_top);
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if(loc == NO_MEM) {
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level--;
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printf("VM: vm_allocpage: findhole failed\n");
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return NULL;
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}
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/* Allocate page of memory for use by VM. As VM
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* is trusted, we don't have to pre-clear it.
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*/
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if((newpage = ALLOC_MEM(CLICKSPERPAGE, 0)) == NO_MEM) {
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level--;
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printf("VM: vm_allocpage: ALLOC_MEM failed\n");
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return NULL;
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}
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*phys = CLICK2ABS(newpage);
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/* Map this page into our address space. */
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if((r=pt_writemap(pt, loc, *phys, I386_PAGE_SIZE,
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I386_VM_PRESENT | I386_VM_USER | I386_VM_WRITE, 0)) != OK) {
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FREE_MEM(newpage, CLICKSPERPAGE);
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printf("vm_allocpage writemap failed\n");
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level--;
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return NULL;
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}
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if((r=sys_vmctl(SELF, VMCTL_FLUSHTLB, 0)) != OK) {
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vm_panic("VMCTL_FLUSHTLB failed", r);
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}
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level--;
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/* Return user-space-ready pointer to it. */
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ret = (void *) arch_map2vir(vmp, loc);
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return ret;
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}
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/*===========================================================================*
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* vm_pagelock *
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*===========================================================================*/
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PUBLIC void vm_pagelock(void *vir, int lockflag)
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{
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/* Mark a page allocated by vm_allocpage() unwritable, i.e. only for VM. */
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vir_bytes m;
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int r;
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u32_t flags = I386_VM_PRESENT | I386_VM_USER;
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pt_t *pt;
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pt = &vmp->vm_pt;
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m = arch_vir2map(vmp, (vir_bytes) vir);
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vm_assert(!(m % I386_PAGE_SIZE));
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if(!lockflag)
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flags |= I386_VM_WRITE;
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/* Update flags. */
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if((r=pt_writemap(pt, m, 0, I386_PAGE_SIZE,
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flags, WMF_OVERWRITE | WMF_WRITEFLAGSONLY)) != OK) {
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vm_panic("vm_lockpage: pt_writemap failed\n", NO_NUM);
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}
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if((r=sys_vmctl(SELF, VMCTL_FLUSHTLB, 0)) != OK) {
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vm_panic("VMCTL_FLUSHTLB failed", r);
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}
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return;
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}
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/*===========================================================================*
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* pt_ptalloc *
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*===========================================================================*/
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PRIVATE int pt_ptalloc(pt_t *pt, int pde, u32_t flags)
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{
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/* Allocate a page table and write its address into the page directory. */
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int i;
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u32_t pt_phys;
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/* Argument must make sense. */
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vm_assert(pde >= 0 && pde < I386_VM_DIR_ENTRIES);
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vm_assert(!(flags & ~(PTF_ALLFLAGS)));
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/* We don't expect to overwrite page directory entry, nor
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* storage for the page table.
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*/
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vm_assert(!(pt->pt_dir[pde] & I386_VM_PRESENT));
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vm_assert(!pt->pt_pt[pde]);
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/* Get storage for the page table. */
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if(!(pt->pt_pt[pde] = vm_allocpage(&pt_phys, VMP_PAGETABLE)))
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return ENOMEM;
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for(i = 0; i < I386_VM_PT_ENTRIES; i++)
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pt->pt_pt[pde][i] = 0; /* Empty entry. */
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/* Make page directory entry.
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* The PDE is always 'present,' 'writable,' and 'user accessible,'
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* relying on the PTE for protection.
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*/
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pt->pt_dir[pde] = (pt_phys & I386_VM_ADDR_MASK) | flags
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| I386_VM_PRESENT | I386_VM_USER | I386_VM_WRITE;
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return OK;
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}
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/*===========================================================================*
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* pt_writemap *
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*===========================================================================*/
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PUBLIC int pt_writemap(pt_t *pt, vir_bytes v, phys_bytes physaddr,
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size_t bytes, u32_t flags, u32_t writemapflags)
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{
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/* Write mapping into page table. Allocate a new page table if necessary. */
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/* Page directory and table entries for this virtual address. */
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int p, pages, pdecheck;
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int finalpde;
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int verify = 0;
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if(writemapflags & WMF_VERIFY)
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verify = 1;
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vm_assert(!(bytes % I386_PAGE_SIZE));
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vm_assert(!(flags & ~(PTF_ALLFLAGS)));
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pages = bytes / I386_PAGE_SIZE;
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/* MAP_NONE means to clear the mapping. It doesn't matter
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* what's actually written into the PTE if I386_VM_PRESENT
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* isn't on, so we can just write MAP_NONE into it.
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*/
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#if SANITYCHECKS
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if(physaddr != MAP_NONE && !(flags & I386_VM_PRESENT)) {
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vm_panic("pt_writemap: writing dir with !P\n", NO_NUM);
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}
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if(physaddr == MAP_NONE && flags) {
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vm_panic("pt_writemap: writing 0 with flags\n", NO_NUM);
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}
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#endif
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finalpde = I386_VM_PDE(v + I386_PAGE_SIZE * pages);
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/* First make sure all the necessary page tables are allocated,
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* before we start writing in any of them, because it's a pain
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* to undo our work properly. Walk the range in page-directory-entry
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* sized leaps.
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*/
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for(pdecheck = I386_VM_PDE(v); pdecheck <= finalpde; pdecheck++) {
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vm_assert(pdecheck >= 0 && pdecheck < I386_VM_DIR_ENTRIES);
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if(pt->pt_dir[pdecheck] & I386_VM_BIGPAGE) {
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printf("pt_writemap: trying to write 0x%lx into 0x%lx\n",
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physaddr, v);
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vm_panic("pt_writemap: BIGPAGE found", NO_NUM);
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}
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if(!(pt->pt_dir[pdecheck] & I386_VM_PRESENT)) {
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int r;
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if(verify) {
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printf("pt_writemap verify: no pde %d\n", pdecheck);
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return EFAULT;
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}
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vm_assert(!pt->pt_dir[pdecheck]);
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if((r=pt_ptalloc(pt, pdecheck, flags)) != OK) {
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/* Couldn't do (complete) mapping.
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* Don't bother freeing any previously
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* allocated page tables, they're
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* still writable, don't point to nonsense,
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* and pt_ptalloc leaves the directory
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* and other data in a consistent state.
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*/
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printf("pt_writemap: pt_ptalloc failed\n", pdecheck);
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return r;
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}
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}
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vm_assert(pt->pt_dir[pdecheck] & I386_VM_PRESENT);
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}
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/* Now write in them. */
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for(p = 0; p < pages; p++) {
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u32_t entry;
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int pde = I386_VM_PDE(v);
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int pte = I386_VM_PTE(v);
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vm_assert(!(v % I386_PAGE_SIZE));
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vm_assert(pte >= 0 && pte < I386_VM_PT_ENTRIES);
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vm_assert(pde >= 0 && pde < I386_VM_DIR_ENTRIES);
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/* Page table has to be there. */
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vm_assert(pt->pt_dir[pde] & I386_VM_PRESENT);
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|
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/* Make sure page directory entry for this page table
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* is marked present and page table entry is available.
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*/
|
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vm_assert((pt->pt_dir[pde] & I386_VM_PRESENT) && pt->pt_pt[pde]);
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|
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#if SANITYCHECKS
|
|
/* We don't expect to overwrite a page. */
|
|
if(!(writemapflags & (WMF_OVERWRITE|WMF_VERIFY)))
|
|
vm_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(maskedentry != entry) {
|
|
printf("pt_writemap: 0x%lx found, masked 0x%lx, 0x%lx expected\n",
|
|
pt->pt_pt[pde][pte], maskedentry, entry);
|
|
return EFAULT;
|
|
}
|
|
} else {
|
|
/* Write pagetable entry. */
|
|
pt->pt_pt[pde][pte] = entry;
|
|
}
|
|
|
|
physaddr += I386_PAGE_SIZE;
|
|
v += I386_PAGE_SIZE;
|
|
}
|
|
|
|
return OK;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* pt_checkrange *
|
|
*===========================================================================*/
|
|
PUBLIC int pt_checkrange(pt_t *pt, vir_bytes v, size_t bytes,
|
|
int write)
|
|
{
|
|
int p, pages, pde;
|
|
|
|
vm_assert(!(bytes % I386_PAGE_SIZE));
|
|
|
|
pages = bytes / I386_PAGE_SIZE;
|
|
|
|
for(p = 0; p < pages; p++) {
|
|
u32_t entry;
|
|
int pde = I386_VM_PDE(v);
|
|
int pte = I386_VM_PTE(v);
|
|
|
|
vm_assert(!(v % I386_PAGE_SIZE));
|
|
vm_assert(pte >= 0 && pte < I386_VM_PT_ENTRIES);
|
|
vm_assert(pde >= 0 && pde < I386_VM_DIR_ENTRIES);
|
|
|
|
/* Page table has to be there. */
|
|
if(!(pt->pt_dir[pde] & I386_VM_PRESENT))
|
|
return EFAULT;
|
|
|
|
/* Make sure page directory entry for this page table
|
|
* is marked present and page table entry is available.
|
|
*/
|
|
vm_assert((pt->pt_dir[pde] & I386_VM_PRESENT) && pt->pt_pt[pde]);
|
|
|
|
if(!(pt->pt_pt[pde][pte] & I386_VM_PRESENT)) {
|
|
return EFAULT;
|
|
}
|
|
|
|
if(write && !(pt->pt_pt[pde][pte] & I386_VM_WRITE)) {
|
|
return EFAULT;
|
|
}
|
|
|
|
v += I386_PAGE_SIZE;
|
|
}
|
|
|
|
return OK;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* pt_new *
|
|
*===========================================================================*/
|
|
PUBLIC int pt_new(pt_t *pt)
|
|
{
|
|
/* Allocate a pagetable root. On i386, 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;
|
|
|
|
/* 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_allocpage(&pt->pt_dir_phys, VMP_PAGEDIR))) {
|
|
return ENOMEM;
|
|
}
|
|
|
|
for(i = 0; i < I386_VM_DIR_ENTRIES; i++) {
|
|
pt->pt_dir[i] = 0; /* invalid entry (I386_VM_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(pt_mapkernel(pt) != OK)
|
|
vm_panic("pt_new: pt_mapkernel failed", NO_NUM);
|
|
|
|
return OK;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* pt_identity *
|
|
*===========================================================================*/
|
|
PUBLIC int pt_identity(pt_t *pt)
|
|
{
|
|
/* Allocate a pagetable that does a 1:1 mapping. */
|
|
int i;
|
|
|
|
/* Allocate page directory. */
|
|
if(!pt->pt_dir &&
|
|
!(pt->pt_dir = vm_allocpage(&pt->pt_dir_phys, VMP_PAGEDIR))) {
|
|
return ENOMEM;
|
|
}
|
|
|
|
for(i = 0; i < I386_VM_DIR_ENTRIES; i++) {
|
|
phys_bytes addr;
|
|
addr = I386_BIG_PAGE_SIZE*i;
|
|
pt->pt_dir[i] = (addr & I386_VM_ADDR_MASK_4MB) |
|
|
I386_VM_BIGPAGE|
|
|
I386_VM_USER|
|
|
I386_VM_PRESENT|I386_VM_WRITE;
|
|
pt->pt_pt[i] = NULL;
|
|
}
|
|
|
|
/* Where to start looking for free virtual address space? */
|
|
pt->pt_virtop = 0;
|
|
|
|
return OK;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* pt_init *
|
|
*===========================================================================*/
|
|
PUBLIC void pt_init(phys_bytes usedlimit)
|
|
{
|
|
/* By default, the kernel gives us a data segment with pre-allocated
|
|
* memory that then can't grow. We want to be able to allocate memory
|
|
* dynamically, however. So here we copy the part of the page table
|
|
* that's ours, so we get a private page table. Then we increase the
|
|
* hardware segment size so we can allocate memory above our stack.
|
|
*/
|
|
pt_t *newpt;
|
|
int s, r;
|
|
vir_bytes v, kpagedir;
|
|
phys_bytes lo, hi;
|
|
vir_bytes extra_clicks;
|
|
u32_t moveup = 0;
|
|
int global_bit_ok = 0;
|
|
int free_pde;
|
|
int p;
|
|
vir_bytes kernlimit;
|
|
vir_bytes sparepages_mem;
|
|
phys_bytes sparepages_ph;
|
|
|
|
/* Shorthand. */
|
|
newpt = &vmp->vm_pt;
|
|
|
|
|
|
/* Get ourselves spare pages. */
|
|
if(!(sparepages_mem = (vir_bytes) aalloc(I386_PAGE_SIZE*SPAREPAGES)))
|
|
vm_panic("pt_init: aalloc for spare failed", NO_NUM);
|
|
if((r=sys_umap(SELF, VM_D, (vir_bytes) sparepages_mem,
|
|
I386_PAGE_SIZE*SPAREPAGES, &sparepages_ph)) != OK)
|
|
vm_panic("pt_init: sys_umap failed", r);
|
|
|
|
for(s = 0; s < SPAREPAGES; s++) {
|
|
sparepages[s].page = (void *) (sparepages_mem + s*I386_PAGE_SIZE);
|
|
sparepages[s].phys = sparepages_ph + s*I386_PAGE_SIZE;
|
|
}
|
|
|
|
missing_spares = 0;
|
|
|
|
/* global bit and 4MB pages available? */
|
|
global_bit_ok = _cpufeature(_CPUF_I386_PGE);
|
|
bigpage_ok = _cpufeature(_CPUF_I386_PSE);
|
|
|
|
/* Set bit for PTE's and PDE's if available. */
|
|
if(global_bit_ok)
|
|
global_bit = I386_VM_GLOBAL;
|
|
|
|
/* The kernel and boot time processes need an identity mapping.
|
|
* We use full PDE's for this without separate page tables.
|
|
* Figure out which pde we can start using for other purposes.
|
|
*/
|
|
id_map_high_pde = usedlimit / I386_BIG_PAGE_SIZE;
|
|
|
|
/* We have to make mappings up till here. */
|
|
free_pde = id_map_high_pde+1;
|
|
|
|
/* Initial (current) range of our virtual address space. */
|
|
lo = CLICK2ABS(vmp->vm_arch.vm_seg[T].mem_phys);
|
|
hi = CLICK2ABS(vmp->vm_arch.vm_seg[S].mem_phys +
|
|
vmp->vm_arch.vm_seg[S].mem_len);
|
|
|
|
vm_assert(!(lo % I386_PAGE_SIZE));
|
|
vm_assert(!(hi % I386_PAGE_SIZE));
|
|
|
|
if(lo < VM_PROCSTART) {
|
|
moveup = VM_PROCSTART - lo;
|
|
vm_assert(!(VM_PROCSTART % I386_PAGE_SIZE));
|
|
vm_assert(!(lo % I386_PAGE_SIZE));
|
|
vm_assert(!(moveup % I386_PAGE_SIZE));
|
|
}
|
|
|
|
/* Make new page table for ourselves, partly copied
|
|
* from the current one.
|
|
*/
|
|
if(pt_new(newpt) != OK)
|
|
vm_panic("pt_init: pt_new failed", NO_NUM);
|
|
|
|
/* Set up mappings for VM process. */
|
|
for(v = lo; v < hi; v += I386_PAGE_SIZE) {
|
|
phys_bytes addr;
|
|
u32_t flags;
|
|
|
|
/* We have to write the new position in the PT,
|
|
* so we can move our segments.
|
|
*/
|
|
if(pt_writemap(newpt, v+moveup, v, I386_PAGE_SIZE,
|
|
I386_VM_PRESENT|I386_VM_WRITE|I386_VM_USER, 0) != OK)
|
|
vm_panic("pt_init: pt_writemap failed", NO_NUM);
|
|
}
|
|
|
|
/* Move segments up too. */
|
|
vmp->vm_arch.vm_seg[T].mem_phys += ABS2CLICK(moveup);
|
|
vmp->vm_arch.vm_seg[D].mem_phys += ABS2CLICK(moveup);
|
|
vmp->vm_arch.vm_seg[S].mem_phys += ABS2CLICK(moveup);
|
|
|
|
/* Allocate us a page table in which to remember page directory
|
|
* pointers.
|
|
*/
|
|
if(!(page_directories = vm_allocpage(&page_directories_phys,
|
|
VMP_PAGETABLE)))
|
|
vm_panic("no virt addr for vm mappings", NO_NUM);
|
|
|
|
memset(page_directories, 0, I386_PAGE_SIZE);
|
|
|
|
/* Increase our hardware data segment to create virtual address
|
|
* space above our stack. We want to increase it to VM_DATATOP,
|
|
* like regular processes have.
|
|
*/
|
|
extra_clicks = ABS2CLICK(VM_DATATOP - hi);
|
|
vmp->vm_arch.vm_seg[S].mem_len += extra_clicks;
|
|
|
|
/* We pretend to the kernel we have a huge stack segment to
|
|
* increase our data segment.
|
|
*/
|
|
vmp->vm_arch.vm_data_top =
|
|
(vmp->vm_arch.vm_seg[S].mem_vir +
|
|
vmp->vm_arch.vm_seg[S].mem_len) << CLICK_SHIFT;
|
|
|
|
/* Where our free virtual address space starts.
|
|
* This is only a hint to the VM system.
|
|
*/
|
|
newpt->pt_virtop = 0;
|
|
|
|
/* Let other functions know VM now has a private page table. */
|
|
vmp->vm_flags |= VMF_HASPT;
|
|
|
|
/* Now reserve another pde for kernel's own mappings. */
|
|
{
|
|
int kernmap_pde;
|
|
phys_bytes addr, len;
|
|
int flags, index = 0;
|
|
u32_t offset = 0;
|
|
|
|
kernmap_pde = free_pde++;
|
|
offset = kernmap_pde * I386_BIG_PAGE_SIZE;
|
|
|
|
while(sys_vmctl_get_mapping(index, &addr, &len,
|
|
&flags) == OK) {
|
|
vir_bytes vir;
|
|
if(index >= MAX_KERNMAPPINGS)
|
|
vm_panic("VM: too many kernel mappings", index);
|
|
kern_mappings[index].phys_addr = addr;
|
|
kern_mappings[index].len = len;
|
|
kern_mappings[index].flags = flags;
|
|
kern_mappings[index].lin_addr = offset;
|
|
kern_mappings[index].flags =
|
|
I386_VM_PRESENT | I386_VM_USER | I386_VM_WRITE |
|
|
global_bit;
|
|
if(flags & VMMF_UNCACHED)
|
|
kern_mappings[index].flags |=
|
|
I386_VM_PWT | I386_VM_PCD;
|
|
if(addr % I386_PAGE_SIZE)
|
|
vm_panic("VM: addr unaligned", addr);
|
|
if(len % I386_PAGE_SIZE)
|
|
vm_panic("VM: len unaligned", len);
|
|
vir = arch_map2vir(&vmproc[VMP_SYSTEM], offset);
|
|
if(sys_vmctl_reply_mapping(index, vir) != OK)
|
|
vm_panic("VM: reply failed", NO_NUM);
|
|
offset += len;
|
|
index++;
|
|
kernmappings++;
|
|
}
|
|
}
|
|
|
|
/* Find a PDE below processes available for mapping in the
|
|
* page directories (readonly).
|
|
*/
|
|
pagedir_pde = free_pde++;
|
|
pagedir_pde_val = (page_directories_phys & I386_VM_ADDR_MASK) |
|
|
I386_VM_PRESENT | I386_VM_USER | I386_VM_WRITE;
|
|
|
|
/* Tell kernel about free pde's. */
|
|
while(free_pde*I386_BIG_PAGE_SIZE < VM_PROCSTART) {
|
|
if((r=sys_vmctl(SELF, VMCTL_I386_FREEPDE, free_pde++)) != OK) {
|
|
vm_panic("VMCTL_I386_FREEPDE failed", r);
|
|
}
|
|
}
|
|
|
|
/* first pde in use by process. */
|
|
proc_pde = free_pde;
|
|
|
|
kernlimit = free_pde*I386_BIG_PAGE_SIZE;
|
|
|
|
/* Increase kernel segment to address this memory. */
|
|
if((r=sys_vmctl(SELF, VMCTL_I386_KERNELLIMIT, kernlimit)) != OK) {
|
|
vm_panic("VMCTL_I386_KERNELLIMIT failed", r);
|
|
}
|
|
|
|
kpagedir = arch_map2vir(&vmproc[VMP_SYSTEM],
|
|
pagedir_pde*I386_BIG_PAGE_SIZE);
|
|
|
|
/* Tell kernel how to get at the page directories. */
|
|
if((r=sys_vmctl(SELF, VMCTL_I386_PAGEDIRS, kpagedir)) != OK) {
|
|
vm_panic("VMCTL_I386_KERNELLIMIT failed", r);
|
|
}
|
|
|
|
/* Give our process the new, copied, private page table. */
|
|
pt_mapkernel(newpt); /* didn't know about vm_dir pages earlier */
|
|
pt_bind(newpt, vmp);
|
|
|
|
/* Now actually enable paging. */
|
|
if(sys_vmctl_enable_paging(vmp->vm_arch.vm_seg) != OK)
|
|
vm_panic("pt_init: enable paging failed", NO_NUM);
|
|
|
|
/* Back to reality - this is where the stack actually is. */
|
|
vmp->vm_arch.vm_seg[S].mem_len -= extra_clicks;
|
|
|
|
/* All OK. */
|
|
return;
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* pt_bind *
|
|
*===========================================================================*/
|
|
PUBLIC int pt_bind(pt_t *pt, struct vmproc *who)
|
|
{
|
|
int slot, ispt;
|
|
u32_t phys;
|
|
|
|
/* Basic sanity checks. */
|
|
vm_assert(who);
|
|
vm_assert(who->vm_flags & VMF_INUSE);
|
|
vm_assert(pt);
|
|
|
|
slot = who->vm_slot;
|
|
vm_assert(slot >= 0);
|
|
vm_assert(slot < ELEMENTS(vmproc));
|
|
vm_assert(slot < I386_VM_PT_ENTRIES);
|
|
|
|
phys = pt->pt_dir_phys & I386_VM_ADDR_MASK;
|
|
vm_assert(pt->pt_dir_phys == phys);
|
|
|
|
/* Update "page directory pagetable." */
|
|
page_directories[slot] = phys | I386_VM_PRESENT|I386_VM_WRITE;
|
|
|
|
#if 0
|
|
printf("VM: slot %d has pde val 0x%lx\n", slot, page_directories[slot]);
|
|
#endif
|
|
/* Tell kernel about new page table root. */
|
|
return sys_vmctl(who->vm_endpoint, VMCTL_I386_SETCR3,
|
|
pt ? pt->pt_dir_phys : 0);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* pt_free *
|
|
*===========================================================================*/
|
|
PUBLIC void pt_free(pt_t *pt)
|
|
{
|
|
/* Free memory associated with this pagetable. */
|
|
int i;
|
|
|
|
for(i = 0; i < I386_VM_DIR_ENTRIES; i++)
|
|
if(pt->pt_pt[i])
|
|
vm_freepages((vir_bytes) pt->pt_pt[i],
|
|
I386_VM_PFA(pt->pt_dir[i]), 1, VMP_PAGETABLE);
|
|
|
|
return;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* pt_mapkernel *
|
|
*===========================================================================*/
|
|
PUBLIC int pt_mapkernel(pt_t *pt)
|
|
{
|
|
int r, i;
|
|
|
|
/* Any i386 page table needs to map in the kernel address space. */
|
|
vm_assert(vmproc[VMP_SYSTEM].vm_flags & VMF_INUSE);
|
|
|
|
if(bigpage_ok) {
|
|
int pde;
|
|
for(pde = 0; pde <= id_map_high_pde; pde++) {
|
|
phys_bytes addr;
|
|
addr = pde * I386_BIG_PAGE_SIZE;
|
|
vm_assert((addr & I386_VM_ADDR_MASK) == addr);
|
|
pt->pt_dir[pde] = addr | I386_VM_PRESENT |
|
|
I386_VM_BIGPAGE | I386_VM_USER |
|
|
I386_VM_WRITE | global_bit;
|
|
}
|
|
} else {
|
|
vm_panic("VM: pt_mapkernel: no bigpage", NO_NUM);
|
|
}
|
|
|
|
if(pagedir_pde >= 0) {
|
|
/* Kernel also wants to know about all page directories. */
|
|
pt->pt_dir[pagedir_pde] = pagedir_pde_val;
|
|
}
|
|
|
|
for(i = 0; i < kernmappings; i++) {
|
|
if(pt_writemap(pt,
|
|
kern_mappings[i].lin_addr,
|
|
kern_mappings[i].phys_addr,
|
|
kern_mappings[i].len,
|
|
kern_mappings[i].flags, 0) != OK) {
|
|
vm_panic("pt_mapkernel: pt_writemap failed", NO_NUM);
|
|
}
|
|
}
|
|
|
|
return OK;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* pt_cycle *
|
|
*===========================================================================*/
|
|
PUBLIC void pt_cycle(void)
|
|
{
|
|
vm_checkspares();
|
|
}
|
|
|