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minix/servers/vm/region.c
Ben Gras 32fbbd370c - pages that points to page directory values of all processes, 
shared with the kernel, mapped into kernel address space; 
   kernel is notified of its location. kernel segment size is
   increased to make it fit.
 - map in kernel and other processes that don't have their
   own page table using single 4MB (global) mapping.
 - new sanity check facility: objects that are allocated with
   the slab allocator are, when running with sanity checking on,
   marked readonly until they are explicitly unlocked using the USE()
   macro.
 - another sanity check facility: collect all uses of memory and
   see if they don't overlap with (a) eachother and (b) free memory
 - own munmap() and munmap_text() functions.
 - exec() recovers from out-of-memory conditions properly now; this
   solves some weird exec() behaviour
 - chew off memory from the same side of the chunk as where we
   start scanning, solving some memory fragmentation issues
 - use avl trees for freelist and phys_ranges in regions
 - implement most useful part of munmap()
 - remap() stuff is GQ's for shared memory
2009-09-21 14:49:49 +00:00

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#define _SYSTEM 1
#include <minix/com.h>
#include <minix/callnr.h>
#include <minix/type.h>
#include <minix/config.h>
#include <minix/const.h>
#include <minix/sysutil.h>
#include <minix/syslib.h>
#include <minix/debug.h>
#include <minix/bitmap.h>
#include <sys/mman.h>
#include <limits.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
#include <stdint.h>
#include <memory.h>
#include "vm.h"
#include "proto.h"
#include "util.h"
#include "glo.h"
#include "region.h"
#include "sanitycheck.h"
#include "physravl.h"
/* Should a physblock be mapped writable? */
#define WRITABLE(r, pb) \
(((r)->flags & (VR_DIRECT | VR_SHARED)) || \
(((r)->flags & VR_WRITABLE) && (pb)->refcount == 1))
FORWARD _PROTOTYPE(struct phys_region *map_new_physblock, (struct vmproc *vmp,
struct vir_region *region, vir_bytes offset, vir_bytes length,
phys_bytes what));
FORWARD _PROTOTYPE(int map_ph_writept, (struct vmproc *vmp, struct vir_region *vr,
struct phys_region *pr));
FORWARD _PROTOTYPE(int map_copy_ph_block, (struct vmproc *vmp, struct vir_region *region, struct phys_region *ph));
FORWARD _PROTOTYPE(struct vir_region *map_copy_region, (struct vmproc *vmp, struct vir_region *vr));
PRIVATE char *map_name(struct vir_region *vr)
{
int type = vr->flags & (VR_ANON|VR_DIRECT);
switch(type) {
case VR_ANON:
return "anonymous";
case VR_DIRECT:
return "direct";
default:
vm_panic("unknown mapping type", type);
}
return "NOTREACHED";
}
/*===========================================================================*
* map_printmap *
*===========================================================================*/
PUBLIC void map_printmap(vmp)
struct vmproc *vmp;
{
struct vir_region *vr;
physr_iter iter;
printf("memory regions in process %d:\n", vmp->vm_endpoint);
for(vr = vmp->vm_regions; vr; vr = vr->next) {
struct phys_region *ph;
int nph = 0;
printf("map_printmap: map_name: %s\n", map_name(vr));
printf("\t0x%lx - 0x%lx (len 0x%lx), %s\n",
vr->vaddr, vr->vaddr + vr->length, vr->length,
map_name(vr));
printf("\t\tphysical: ");
physr_start_iter_least(vr->phys, &iter);
while((ph = physr_get_iter(&iter))) {
printf("0x%lx-0x%lx (refs %d): phys 0x%lx ",
vr->vaddr + ph->offset,
vr->vaddr + ph->offset + ph->ph->length,
ph->ph->refcount,
ph->ph->phys);
nph++;
physr_incr_iter(&iter);
}
printf(" (phregions %d)\n", nph);
}
}
#if SANITYCHECKS
/*===========================================================================*
* map_sanitycheck *
*===========================================================================*/
PUBLIC void map_sanitycheck(char *file, int line)
{
struct vmproc *vmp;
/* Macro for looping over all physical blocks of all regions of
* all processes.
*/
#define ALLREGIONS(regioncode, physcode) \
for(vmp = vmproc; vmp < &vmproc[VMP_NR]; vmp++) { \
struct vir_region *vr; \
if(!(vmp->vm_flags & VMF_INUSE)) \
continue; \
for(vr = vmp->vm_regions; vr; vr = vr->next) { \
physr_iter iter; \
struct phys_region *pr; \
regioncode; \
physr_start_iter_least(vr->phys, &iter); \
while((pr = physr_get_iter(&iter))) { \
physcode; \
physr_incr_iter(&iter); \
} \
} \
}
#define MYSLABSANE(s) MYASSERT(slabsane_f(__FILE__, __LINE__, s, sizeof(*(s))))
/* Basic pointers check. */
ALLREGIONS(MYSLABSANE(vr),MYSLABSANE(pr); MYSLABSANE(pr->ph);MYSLABSANE(pr->parent));
ALLREGIONS(/* MYASSERT(vr->parent == vmp) */,MYASSERT(pr->parent == vr););
/* Do counting for consistency check. */
ALLREGIONS(;,USE(pr->ph, pr->ph->seencount = 0;););
ALLREGIONS(;,USE(pr->ph, pr->ph->seencount++;);
if(pr->ph->seencount == 1) {
MYASSERT(usedpages_add(pr->ph->phys,
pr->ph->length) == OK);
}
);
/* Do consistency check. */
ALLREGIONS(if(vr->next) {
MYASSERT(vr->vaddr < vr->next->vaddr);
MYASSERT(vr->vaddr + vr->length <= vr->next->vaddr);
}
MYASSERT(!(vr->vaddr % VM_PAGE_SIZE));,
if(pr->ph->refcount != pr->ph->seencount) {
map_printmap(vmp);
printf("ph in vr 0x%lx: 0x%lx-0x%lx refcount %d "
"but seencount %lu\n",
vr, pr->offset,
pr->offset + pr->ph->length,
pr->ph->refcount, pr->ph->seencount);
}
{
int n_others = 0;
struct phys_region *others;
if(pr->ph->refcount > 0) {
MYASSERT(pr->ph->firstregion);
if(pr->ph->refcount == 1) {
MYASSERT(pr->ph->firstregion == pr);
}
} else {
MYASSERT(!pr->ph->firstregion);
}
for(others = pr->ph->firstregion; others;
others = others->next_ph_list) {
MYSLABSANE(others);
MYASSERT(others->ph == pr->ph);
n_others++;
}
MYASSERT(pr->ph->refcount == n_others);
}
MYASSERT(pr->ph->refcount == pr->ph->seencount);
MYASSERT(!(pr->offset % VM_PAGE_SIZE));
MYASSERT(!(pr->ph->length % VM_PAGE_SIZE)););
}
#endif
/*=========================================================================*
* map_ph_writept *
*=========================================================================*/
PRIVATE int map_ph_writept(struct vmproc *vmp, struct vir_region *vr,
struct phys_region *pr)
{
int rw;
struct phys_block *pb = pr->ph;
vm_assert(!(vr->vaddr % VM_PAGE_SIZE));
vm_assert(!(pb->length % VM_PAGE_SIZE));
vm_assert(!(pr->offset % VM_PAGE_SIZE));
vm_assert(pb->refcount > 0);
if(WRITABLE(vr, pb))
rw = PTF_WRITE;
else
rw = 0;
if(pt_writemap(&vmp->vm_pt, vr->vaddr + pr->offset,
pb->phys, pb->length, PTF_PRESENT | PTF_USER | rw,
WMF_OVERWRITE) != OK) {
printf("VM: map_writept: pt_writemap failed\n");
return ENOMEM;
}
return OK;
}
/*===========================================================================*
* region_find_slot *
*===========================================================================*/
PRIVATE vir_bytes region_find_slot(struct vmproc *vmp,
vir_bytes minv, vir_bytes maxv, vir_bytes length,
struct vir_region **prev)
{
struct vir_region *firstregion = vmp->vm_regions, *prevregion = NULL;
vir_bytes startv;
int foundflag = 0;
SANITYCHECK(SCL_FUNCTIONS);
/* We must be in paged mode to be able to do this. */
vm_assert(vm_paged);
/* Length must be reasonable. */
vm_assert(length > 0);
/* Special case: allow caller to set maxv to 0 meaning 'I want
* it to be mapped in right here.'
*/
if(maxv == 0) {
maxv = minv + length;
/* Sanity check. */
if(maxv <= minv) {
printf("region_find_slot: minv 0x%lx and bytes 0x%lx\n",
minv, length);
map_printmap(vmp);
return (vir_bytes) -1;
}
}
/* Basic input sanity checks. */
vm_assert(!(length % VM_PAGE_SIZE));
if(minv >= maxv) {
printf("VM: 1 minv: 0x%lx maxv: 0x%lx length: 0x%lx\n",
minv, maxv, length);
}
vm_assert(minv < maxv);
vm_assert(minv + length <= maxv);
#define FREEVRANGE(rangestart, rangeend, foundcode) { \
vir_bytes frstart = (rangestart), frend = (rangeend); \
frstart = MAX(frstart, minv); \
frend = MIN(frend, maxv); \
if(frend > frstart && (frend - frstart) >= length) { \
startv = frstart; \
foundflag = 1; \
foundcode; \
} }
/* This is the free virtual address space before the first region. */
FREEVRANGE(0, firstregion ? firstregion->vaddr : VM_DATATOP, ;);
if(!foundflag) {
struct vir_region *vr;
for(vr = vmp->vm_regions; vr && !foundflag; vr = vr->next) {
FREEVRANGE(vr->vaddr + vr->length,
vr->next ? vr->next->vaddr : VM_DATATOP,
prevregion = vr;);
}
}
if(!foundflag) {
printf("VM: region_find_slot: no 0x%lx bytes found for %d between 0x%lx and 0x%lx\n",
length, vmp->vm_endpoint, minv, maxv);
map_printmap(vmp);
return (vir_bytes) -1;
}
#if SANITYCHECKS
if(prevregion) vm_assert(prevregion->vaddr < startv);
#endif
/* However we got it, startv must be in the requested range. */
vm_assert(startv >= minv);
vm_assert(startv < maxv);
vm_assert(startv + length <= maxv);
if (prev)
*prev = prevregion;
return startv;
}
/*===========================================================================*
* map_page_region *
*===========================================================================*/
PUBLIC struct vir_region *map_page_region(vmp, minv, maxv, length,
what, flags, mapflags)
struct vmproc *vmp;
vir_bytes minv;
vir_bytes maxv;
vir_bytes length;
vir_bytes what;
u32_t flags;
int mapflags;
{
struct vir_region *prevregion = NULL, *newregion;
vir_bytes startv;
struct phys_region *ph;
physr_avl *phavl;
SANITYCHECK(SCL_FUNCTIONS);
startv = region_find_slot(vmp, minv, maxv, length, &prevregion);
if (startv == (vir_bytes) -1)
return NULL;
/* Now we want a new region. */
if(!SLABALLOC(newregion)) {
printf("VM: map_page_region: allocating region failed\n");
return NULL;
}
/* Fill in node details. */
USE(newregion,
newregion->vaddr = startv;
newregion->length = length;
newregion->flags = flags;
newregion->tag = VRT_NONE;
newregion->parent = vmp;);
SLABALLOC(phavl);
if(!phavl) {
printf("VM: map_page_region: allocating phys avl failed\n");
SLABFREE(newregion);
return NULL;
}
USE(newregion, newregion->phys = phavl;);
physr_init(newregion->phys);
/* If we know what we're going to map to, map it right away. */
if(what != MAP_NONE) {
struct phys_region *pr;
vm_assert(!(what % VM_PAGE_SIZE));
vm_assert(!(length % VM_PAGE_SIZE));
vm_assert(!(startv % VM_PAGE_SIZE));
vm_assert(!(mapflags & MF_PREALLOC));
if(!(pr=map_new_physblock(vmp, newregion, 0, length, what))) {
printf("VM: map_new_physblock failed\n");
SLABFREE(newregion->phys);
SLABFREE(newregion);
return NULL;
}
if(map_ph_writept(vmp, newregion, pr) != OK) {
printf("VM: map_region_writept failed\n");
SLABFREE(newregion);
return NULL;
}
}
if((flags & VR_ANON) && (mapflags & MF_PREALLOC)) {
if(map_handle_memory(vmp, newregion, 0, length, 1) != OK) {
printf("VM: map_page_region: prealloc failed\n");
SLABFREE(newregion->phys);
SLABFREE(newregion);
return NULL;
}
}
/* Link it. */
if(prevregion) {
vm_assert(prevregion->vaddr < newregion->vaddr);
USE(newregion, newregion->next = prevregion->next;);
USE(prevregion, prevregion->next = newregion;);
} else {
USE(newregion, newregion->next = vmp->vm_regions;);
vmp->vm_regions = newregion;
}
#if SANITYCHECKS
vm_assert(startv == newregion->vaddr);
if(newregion->next) {
vm_assert(newregion->vaddr < newregion->next->vaddr);
}
#endif
SANITYCHECK(SCL_FUNCTIONS);
return newregion;
}
/*===========================================================================*
* pb_unreferenced *
*===========================================================================*/
void pb_unreferenced(struct vir_region *region, struct phys_region *pr)
{
struct phys_block *pb;
int remap = 0;
pb = pr->ph;
vm_assert(pb->refcount > 0);
USE(pb, pb->refcount--;);
vm_assert(pb->refcount >= 0);
if(pb->firstregion == pr) {
USE(pb, pb->firstregion = pr->next_ph_list;);
} else {
struct phys_region *others;
for(others = pb->firstregion; others;
others = others->next_ph_list) {
vm_assert(others->ph == pb);
if(others->next_ph_list == pr) {
USE(others, others->next_ph_list = pr->next_ph_list;);
break;
}
}
vm_assert(others); /* Otherwise, wasn't on the list. */
}
if(pb->refcount == 0) {
vm_assert(!pb->firstregion);
if(region->flags & VR_ANON) {
FREE_MEM(ABS2CLICK(pb->phys),
ABS2CLICK(pb->length));
} else if(region->flags & VR_DIRECT) {
; /* No action required. */
} else {
vm_panic("strange phys flags", NO_NUM);
}
SLABFREE(pb);
} else if(WRITABLE(region, pb)) {
/* If a writable piece of physical memory is now only
* referenced once, map it writable right away instead of
* waiting for a page fault.
*/
vm_assert(pb);
vm_assert(pb->firstregion);
vm_assert(!pb->firstregion->next_ph_list);
vm_assert(pb->firstregion->ph == pb);
vm_assert(pb->firstregion->ph == pb);
if(map_ph_writept(pb->firstregion->parent->parent,
pb->firstregion->parent, pb->firstregion) != OK) {
vm_panic("pb_unreferenced: writept", NO_NUM);
}
}
}
/*===========================================================================*
* map_subfree *
*===========================================================================*/
PRIVATE int map_subfree(struct vmproc *vmp,
struct vir_region *region, vir_bytes len)
{
struct phys_region *pr, *nextpr;
physr_iter iter;
#if SANITYCHECKS
{
physr_start_iter_least(region->phys, &iter);
while((pr = physr_get_iter(&iter))) {
struct phys_region *others;
struct phys_block *pb;
pb = pr->ph;
for(others = pb->firstregion; others;
others = others->next_ph_list) {
vm_assert(others->ph == pb);
}
physr_incr_iter(&iter);
}
}
#endif
physr_start_iter_least(region->phys, &iter);
while((pr = physr_get_iter(&iter))) {
physr_incr_iter(&iter);
if(pr->offset >= len)
break;
if(pr->offset + pr->ph->length <= len) {
pb_unreferenced(region, pr);
physr_remove(region->phys, pr->offset);
physr_start_iter_least(region->phys, &iter);
SLABFREE(pr);
} else {
vir_bytes sublen;
vm_assert(len > pr->offset);
vm_assert(len < pr->offset + pr->ph->length);
vm_assert(pr->ph->refcount > 0);
sublen = len - pr->offset;
if(pr->ph->refcount > 1) {
int r;
r = map_copy_ph_block(vmp, region, pr);
if(r != OK)
return r;
}
vm_assert(pr->ph->refcount == 1);
FREE_MEM(ABS2CLICK(pr->ph->phys), ABS2CLICK(sublen));
USE(pr, pr->offset += sublen;);
USE(pr->ph,
pr->ph->phys += sublen;
pr->ph->length -= sublen;);
}
}
return OK;
}
/*===========================================================================*
* map_free *
*===========================================================================*/
PRIVATE int map_free(struct vmproc *vmp, struct vir_region *region)
{
int r;
if((r=map_subfree(vmp, region, region->length)) != OK)
return r;
SLABFREE(region->phys);
SLABFREE(region);
return OK;
}
/*========================================================================*
* map_free_proc *
*========================================================================*/
PUBLIC int map_free_proc(vmp)
struct vmproc *vmp;
{
struct vir_region *r, *nextr;
SANITYCHECK(SCL_FUNCTIONS);
for(r = vmp->vm_regions; r; r = nextr) {
nextr = r->next;
SANITYCHECK(SCL_DETAIL);
#if SANITYCHECKS
nocheck++;
#endif
map_free(vmp, r);
vmp->vm_regions = nextr; /* For sanity checks. */
#if SANITYCHECKS
nocheck--;
#endif
SANITYCHECK(SCL_DETAIL);
}
vmp->vm_regions = NULL;
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
/*===========================================================================*
* map_lookup *
*===========================================================================*/
PUBLIC struct vir_region *map_lookup(vmp, offset)
struct vmproc *vmp;
vir_bytes offset;
{
struct vir_region *r;
SANITYCHECK(SCL_FUNCTIONS);
if(!vmp->vm_regions)
vm_panic("process has no regions", vmp->vm_endpoint);
for(r = vmp->vm_regions; r; r = r->next) {
if(offset >= r->vaddr && offset < r->vaddr + r->length)
return r;
}
SANITYCHECK(SCL_FUNCTIONS);
return NULL;
}
/*===========================================================================*
* map_new_physblock *
*===========================================================================*/
PRIVATE struct phys_region *map_new_physblock(vmp, region, offset, length, what_mem)
struct vmproc *vmp;
struct vir_region *region;
vir_bytes offset;
vir_bytes length;
phys_bytes what_mem;
{
struct phys_region *newphysr;
struct phys_block *newpb;
phys_bytes mem_clicks, clicks;
vir_bytes mem;
SANITYCHECK(SCL_FUNCTIONS);
vm_assert(!(length % VM_PAGE_SIZE));
NOTRUNNABLE(vmp->vm_endpoint);
/* Allocate things necessary for this chunk of memory. */
if(!SLABALLOC(newphysr))
return NULL;
if(!SLABALLOC(newpb)) {
SLABFREE(newphysr);
return NULL;
}
/* Memory for new physical block. */
clicks = CLICKSPERPAGE * length / VM_PAGE_SIZE;
if(what_mem == MAP_NONE) {
u32_t af = PAF_CLEAR;
if(region->flags & VR_PHYS64K)
af |= PAF_ALIGN64K;
if(region->flags & VR_LOWER16MB)
af |= PAF_LOWER16MB;
if(region->flags & VR_LOWER1MB)
af |= PAF_LOWER1MB;
if((mem_clicks = ALLOC_MEM(clicks, af)) == NO_MEM) {
SLABFREE(newpb);
SLABFREE(newphysr);
printf("map_new_physblock: couldn't allocate\n");
return NULL;
}
mem = CLICK2ABS(mem_clicks);
} else {
mem = what_mem;
}
SANITYCHECK(SCL_DETAIL);
/* New physical block. */
USE(newpb,
newpb->phys = mem;
newpb->refcount = 1;
newpb->length = length;
newpb->firstregion = newphysr;);
/* New physical region. */
USE(newphysr,
newphysr->offset = offset;
newphysr->ph = newpb;
newphysr->parent = region;
newphysr->next_ph_list = NULL; /* No other references to this block. */);
/* Update pagetable. */
vm_assert(!(length % VM_PAGE_SIZE));
vm_assert(!(newpb->length % VM_PAGE_SIZE));
SANITYCHECK(SCL_DETAIL);
if(map_ph_writept(vmp, region, newphysr) != OK) {
if(what_mem == MAP_NONE)
FREE_MEM(mem_clicks, clicks);
SLABFREE(newpb);
SLABFREE(newphysr);
printf("map_new_physblock: map_ph_writept failed\n");
return NULL;
}
physr_insert(region->phys, newphysr);
SANITYCHECK(SCL_FUNCTIONS);
return newphysr;
}
/*===========================================================================*
* map_copy_ph_block *
*===========================================================================*/
PRIVATE int map_copy_ph_block(vmp, region, ph)
struct vmproc *vmp;
struct vir_region *region;
struct phys_region *ph;
{
int r;
phys_bytes newmem, newmem_cl, clicks;
struct phys_block *newpb;
u32_t af = 0;
SANITYCHECK(SCL_FUNCTIONS);
/* This is only to be done if there is more than one copy. */
vm_assert(ph->ph->refcount > 1);
/* Do actual copy on write; allocate new physblock. */
if(!SLABALLOC(newpb)) {
printf("VM: map_copy_ph_block: couldn't allocate newpb\n");
SANITYCHECK(SCL_FUNCTIONS);
return ENOMEM;
}
clicks = CLICKSPERPAGE * ph->ph->length / VM_PAGE_SIZE;
vm_assert(CLICK2ABS(clicks) == ph->ph->length);
if(region->flags & VR_PHYS64K)
af |= PAF_ALIGN64K;
NOTRUNNABLE(vmp->vm_endpoint);
if((newmem_cl = ALLOC_MEM(clicks, af)) == NO_MEM) {
printf("VM: map_copy_ph_block: couldn't allocate new block\n");
SLABFREE(newpb);
return ENOMEM;
}
newmem = CLICK2ABS(newmem_cl);
vm_assert(ABS2CLICK(newmem) == newmem_cl);
pb_unreferenced(region, ph);
vm_assert(ph->ph->refcount > 0);
USE(newpb,
newpb->length = ph->ph->length;
newpb->refcount = 1;
newpb->phys = newmem;
newpb->firstregion = ph;);
USE(ph, ph->next_ph_list = NULL;);
NOTRUNNABLE(vmp->vm_endpoint);
/* Copy old memory to new memory. */
if((r=sys_abscopy(ph->ph->phys, newpb->phys, newpb->length)) != OK) {
printf("VM: map_copy_ph_block: sys_abscopy failed\n");
SANITYCHECK(SCL_FUNCTIONS);
return r;
}
#if VMSTATS
vmp->vm_bytecopies += newpb->length;
#endif
/* Reference new block. */
USE(ph, ph->ph = newpb;);
/* Check reference counts. */
SANITYCHECK(SCL_DETAIL);
/* Update pagetable with new address.
* This will also make it writable.
*/
r = map_ph_writept(vmp, region, ph);
if(r != OK)
vm_panic("map_copy_ph_block: map_ph_writept failed", r);
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
/*===========================================================================*
* map_pf *
*===========================================================================*/
PUBLIC int map_pf(vmp, region, offset, write)
struct vmproc *vmp;
struct vir_region *region;
vir_bytes offset;
int write;
{
vir_bytes virpage;
struct phys_region *ph;
int r = OK;
vm_assert(offset >= 0);
vm_assert(offset < region->length);
vm_assert(region->flags & VR_ANON);
vm_assert(!(region->vaddr % VM_PAGE_SIZE));
virpage = offset - offset % VM_PAGE_SIZE;
SANITYCHECK(SCL_FUNCTIONS);
NOTRUNNABLE(vmp->vm_endpoint);
if((ph = physr_search(region->phys, offset, AVL_LESS_EQUAL)) &&
(ph->offset <= offset && offset < ph->offset + ph->ph->length)) {
/* Pagefault in existing block. Do copy-on-write. */
vm_assert(write);
vm_assert(region->flags & VR_WRITABLE);
vm_assert(ph->ph->refcount > 0);
if(WRITABLE(region, ph->ph)) {
r = map_ph_writept(vmp, region, ph);
if(r != OK)
printf("map_ph_writept failed\n");
} else {
r = map_copy_ph_block(vmp, region, ph);
if(r != OK)
printf("map_copy_ph_block failed\n");
}
} else {
/* Pagefault in non-existing block. Map in new block. */
if(!map_new_physblock(vmp, region, virpage, VM_PAGE_SIZE, MAP_NONE)) {
printf("map_new_physblock failed\n");
r = ENOMEM;
}
}
if(r != OK)
printf("VM: map_pf: failed (%d)\n", r);
SANITYCHECK(SCL_FUNCTIONS);
return r;
}
/*===========================================================================*
* map_handle_memory *
*===========================================================================*/
PUBLIC int map_handle_memory(vmp, region, offset, length, write)
struct vmproc *vmp;
struct vir_region *region;
vir_bytes offset, length;
int write;
{
struct phys_region *physr, *nextphysr;
int changes = 0;
physr_iter iter;
NOTRUNNABLE(vmp->vm_endpoint);
#define FREE_RANGE_HERE(er1, er2) { \
struct phys_region *r1 = (er1), *r2 = (er2); \
vir_bytes start = offset, end = offset + length; \
if(r1) { \
start = MAX(start, r1->offset + r1->ph->length); } \
if(r2) { \
end = MIN(end, r2->offset); } \
if(start < end) { \
int r; \
SANITYCHECK(SCL_DETAIL); \
if(!map_new_physblock(vmp, region, start, \
end-start, MAP_NONE) != OK) { \
SANITYCHECK(SCL_DETAIL); \
return ENOMEM; \
} \
changes++; \
} }
SANITYCHECK(SCL_FUNCTIONS);
vm_assert(region->flags & VR_ANON);
vm_assert(!(region->vaddr % VM_PAGE_SIZE));
vm_assert(!(offset % VM_PAGE_SIZE));
vm_assert(!(length % VM_PAGE_SIZE));
vm_assert(!write || (region->flags & VR_WRITABLE));
physr_start_iter(region->phys, &iter, offset, AVL_LESS_EQUAL);
physr = physr_get_iter(&iter);
if(!physr || offset < physr->offset) {
physr_iter previter;
struct phys_region *prevphysr;
previter = iter;
physr_decr_iter(&iter);
prevphysr = physr_get_iter(&iter);
FREE_RANGE_HERE(prevphysr, physr);
iter = previter;
}
while(physr) {
int r;
SANITYCHECK(SCL_DETAIL);
if(write) {
vm_assert(physr->ph->refcount > 0);
if(!WRITABLE(region, physr->ph)) {
SANITYCHECK(SCL_DETAIL);
r = map_copy_ph_block(vmp, region, physr);
if(r != OK) {
printf("VM: map_handle_memory: no copy\n");
return r;
}
changes++;
SANITYCHECK(SCL_DETAIL);
} else {
SANITYCHECK(SCL_DETAIL);
if((r=map_ph_writept(vmp, region, physr)) != OK) {
printf("VM: map_ph_writept failed\n");
return r;
}
changes++;
SANITYCHECK(SCL_DETAIL);
}
}
SANITYCHECK(SCL_DETAIL);
physr_incr_iter(&iter);
nextphysr = physr_get_iter(&iter);
FREE_RANGE_HERE(physr, nextphysr);
SANITYCHECK(SCL_DETAIL);
if(nextphysr) {
if(nextphysr->offset >= offset + length)
break;
}
physr = nextphysr;
}
SANITYCHECK(SCL_FUNCTIONS);
vm_assert(changes > 0);
return OK;
}
#if SANITYCHECKS
static int countregions(struct vir_region *vr)
{
int n = 0;
struct phys_region *ph;
physr_iter iter;
physr_start_iter_least(vr->phys, &iter);
while((ph = physr_get_iter(&iter))) {
n++;
physr_incr_iter(&iter);
}
return n;
}
#endif
/*===========================================================================*
* map_copy_region *
*===========================================================================*/
PRIVATE struct vir_region *map_copy_region(struct vmproc *vmp, struct vir_region *vr)
{
/* map_copy_region creates a complete copy of the vir_region
* data structure, linking in the same phys_blocks directly,
* but all in limbo, i.e., the caller has to link the vir_region
* to a process. Therefore it doesn't increase the refcount in
* the phys_block; the caller has to do this once it's linked.
* The reason for this is to keep the sanity checks working
* within this function.
*/
struct vir_region *newvr;
struct phys_region *ph;
physr_iter iter;
physr_avl *phavl;
#if SANITYCHECKS
int cr;
cr = countregions(vr);
#endif
if(!SLABALLOC(newvr))
return NULL;
SLABALLOC(phavl);
if(!phavl) {
SLABFREE(newvr);
return NULL;
}
USE(newvr,
*newvr = *vr;
newvr->next = NULL;
newvr->phys = phavl;
);
physr_init(newvr->phys);
SANITYCHECK(SCL_FUNCTIONS);
physr_start_iter_least(vr->phys, &iter);
while((ph = physr_get_iter(&iter))) {
struct phys_region *newph;
if(!SLABALLOC(newph)) {
map_free(vmp, newvr);
return NULL;
}
USE(newph,
newph->ph = ph->ph;
newph->next_ph_list = NULL;
newph->parent = newvr;
newph->offset = ph->offset;);
physr_insert(newvr->phys, newph);
SANITYCHECK(SCL_DETAIL);
vm_assert(countregions(vr) == cr);
physr_incr_iter(&iter);
}
vm_assert(countregions(vr) == countregions(newvr));
SANITYCHECK(SCL_FUNCTIONS);
return newvr;
}
/*=========================================================================*
* map_writept *
*=========================================================================*/
PUBLIC int map_writept(struct vmproc *vmp)
{
struct vir_region *vr;
struct phys_region *ph;
int r;
for(vr = vmp->vm_regions; vr; vr = vr->next) {
physr_iter iter;
physr_start_iter_least(vr->phys, &iter);
while((ph = physr_get_iter(&iter))) {
if((r=map_ph_writept(vmp, vr, ph)) != OK) {
printf("VM: map_writept: failed\n");
return r;
}
physr_incr_iter(&iter);
}
}
return OK;
}
/*========================================================================*
* map_proc_copy *
*========================================================================*/
PUBLIC int map_proc_copy(dst, src)
struct vmproc *dst;
struct vmproc *src;
{
struct vir_region *vr, *prevvr = NULL;
dst->vm_regions = NULL;
SANITYCHECK(SCL_FUNCTIONS);
PT_SANE(&src->vm_pt);
for(vr = src->vm_regions; vr; vr = vr->next) {
physr_iter iter_orig, iter_new;
struct vir_region *newvr;
struct phys_region *orig_ph, *new_ph;
SANITYCHECK(SCL_DETAIL);
if(!(newvr = map_copy_region(dst, vr))) {
map_free_proc(dst);
SANITYCHECK(SCL_FUNCTIONS);
return ENOMEM;
}
SANITYCHECK(SCL_DETAIL);
USE(newvr, newvr->parent = dst;);
if(prevvr) { USE(prevvr, prevvr->next = newvr;); }
else { dst->vm_regions = newvr; }
physr_start_iter_least(vr->phys, &iter_orig);
physr_start_iter_least(newvr->phys, &iter_new);
while((orig_ph = physr_get_iter(&iter_orig))) {
struct phys_block *pb;
new_ph = physr_get_iter(&iter_new);
/* Check two physregions both are nonnull,
* are different, and match physblocks.
*/
vm_assert(new_ph);
vm_assert(orig_ph);
vm_assert(orig_ph != new_ph);
pb = orig_ph->ph;
vm_assert(pb == new_ph->ph);
/* Link in new physregion. */
vm_assert(!new_ph->next_ph_list);
USE(new_ph, new_ph->next_ph_list = pb->firstregion;);
USE(pb, pb->firstregion = new_ph;);
/* Increase phys block refcount */
vm_assert(pb->refcount > 0);
USE(pb, pb->refcount++;);
vm_assert(pb->refcount > 1);
/* Get next new physregion */
physr_incr_iter(&iter_orig);
physr_incr_iter(&iter_new);
}
vm_assert(!physr_get_iter(&iter_new));
SANITYCHECK(SCL_DETAIL);
prevvr = newvr;
SANITYCHECK(SCL_DETAIL);
}
SANITYCHECK(SCL_DETAIL);
PT_SANE(&src->vm_pt);
map_writept(src);
PT_SANE(&src->vm_pt);
map_writept(dst);
PT_SANE(&dst->vm_pt);
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
/*========================================================================*
* map_proc_kernel *
*========================================================================*/
PUBLIC struct vir_region *map_proc_kernel(struct vmproc *vmp)
{
struct vir_region *vr;
/* We assume these are the first regions to be mapped to
* make the function a bit simpler (free all regions on error).
*/
vm_assert(!vmp->vm_regions);
vm_assert(vmproc[VMP_SYSTEM].vm_flags & VMF_INUSE);
vm_assert(!(KERNEL_TEXT % VM_PAGE_SIZE));
vm_assert(!(KERNEL_TEXT_LEN % VM_PAGE_SIZE));
vm_assert(!(KERNEL_DATA % VM_PAGE_SIZE));
vm_assert(!(KERNEL_DATA_LEN % VM_PAGE_SIZE));
if(!(vr = map_page_region(vmp, KERNEL_TEXT, 0, KERNEL_TEXT_LEN,
KERNEL_TEXT, VR_DIRECT | VR_WRITABLE | VR_NOPF, 0)) ||
!(vr = map_page_region(vmp, KERNEL_DATA, 0, KERNEL_DATA_LEN,
KERNEL_DATA, VR_DIRECT | VR_WRITABLE | VR_NOPF, 0))) {
map_free_proc(vmp);
return NULL;
}
return vr; /* Return pointer not useful, just non-NULL. */
}
/*========================================================================*
* map_region_extend *
*========================================================================*/
PUBLIC int map_region_extend(struct vmproc *vmp, struct vir_region *vr,
vir_bytes delta)
{
vir_bytes end;
vm_assert(vr);
vm_assert(vr->flags & VR_ANON);
vm_assert(!(delta % VM_PAGE_SIZE));
if(!delta) return OK;
end = vr->vaddr + vr->length;
vm_assert(end >= vr->vaddr);
if(end + delta <= end) {
printf("VM: strange delta 0x%lx\n", delta);
return ENOMEM;
}
if(!vr->next || end + delta <= vr->next->vaddr) {
USE(vr, vr->length += delta;);
return OK;
}
map_printmap(vmp);
return ENOMEM;
}
/*========================================================================*
* map_region_shrink *
*========================================================================*/
PUBLIC int map_region_shrink(struct vir_region *vr, vir_bytes delta)
{
vm_assert(vr);
vm_assert(vr->flags & VR_ANON);
vm_assert(!(delta % VM_PAGE_SIZE));
#if 0
printf("VM: ignoring region shrink\n");
#endif
return OK;
}
PUBLIC struct vir_region *map_region_lookup_tag(vmp, tag)
struct vmproc *vmp;
u32_t tag;
{
struct vir_region *vr;
for(vr = vmp->vm_regions; vr; vr = vr->next)
if(vr->tag == tag)
return vr;
return NULL;
}
PUBLIC void map_region_set_tag(struct vir_region *vr, u32_t tag)
{
USE(vr, vr->tag = tag;);
}
PUBLIC u32_t map_region_get_tag(struct vir_region *vr)
{
return vr->tag;
}
/*========================================================================*
* map_unmap_region *
*========================================================================*/
PUBLIC int map_unmap_region(struct vmproc *vmp, struct vir_region *region,
vir_bytes len)
{
/* Shrink the region by 'len' bytes, from the start. Unreference
* memory it used to reference if any.
*/
struct vir_region *r, *nextr, *prev = NULL;
vir_bytes regionstart;
SANITYCHECK(SCL_FUNCTIONS);
for(r = vmp->vm_regions; r; r = r->next) {
if(r == region)
break;
prev = r;
}
SANITYCHECK(SCL_DETAIL);
if(r == NULL)
vm_panic("map_unmap_region: region not found\n", NO_NUM);
if(len > r->length || (len % VM_PAGE_SIZE)) {
printf("VM: bogus length 0x%lx\n", len);
return EINVAL;
}
if(!(r->flags & VR_ANON)) {
printf("VM: only unmap anonymous memory\n");
return EINVAL;
}
regionstart = r->vaddr;
if(len == r->length) {
/* Whole region disappears. Unlink and free it. */
if(!prev) {
vmp->vm_regions = r->next;
} else {
USE(prev, prev->next = r->next;);
}
map_free(vmp, r);
} else {
struct phys_region *pr;
physr_iter iter;
/* Region shrinks. First unreference its memory
* and then shrink the region.
*/
map_subfree(vmp, r, len);
USE(r,
r->vaddr += len;
r->length -= len;);
physr_start_iter_least(r->phys, &iter);
/* vaddr has increased; to make all the phys_regions
* point to the same addresses, make them shrink by the
* same amount.
*/
while((pr = physr_get_iter(&iter))) {
vm_assert(pr->offset >= len);
USE(pr, pr->offset -= len;);
physr_incr_iter(&iter);
}
}
SANITYCHECK(SCL_DETAIL);
if(pt_writemap(&vmp->vm_pt, regionstart,
MAP_NONE, len, 0, WMF_OVERWRITE) != OK) {
printf("VM: map_unmap_region: pt_writemap failed\n");
return ENOMEM;
}
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
/*========================================================================*
* map_remap *
*========================================================================*/
PUBLIC int map_remap(struct vmproc *dvmp, vir_bytes da, size_t size,
struct vir_region *region, vir_bytes *r)
{
struct vir_region *vr, *prev;
struct phys_region *ph;
vir_bytes startv, dst_addr;
physr_iter iter;
SANITYCHECK(SCL_FUNCTIONS);
/* da is handled differently */
if (!da)
dst_addr = dvmp->vm_stacktop;
else
dst_addr = da;
dst_addr = arch_vir2map(dvmp, dst_addr);
prev = NULL;
/* round up to page size */
if (size % I386_PAGE_SIZE)
size += I386_PAGE_SIZE - size % I386_PAGE_SIZE;
startv = region_find_slot(dvmp, dst_addr, VM_DATATOP, size, &prev);
if (startv == (vir_bytes) -1) {
printf("map_remap: search %x...\n", dst_addr);
map_printmap(dvmp);
return ENOMEM;
}
/* when the user specifies the address, we cannot change it */
if (da && (startv != dst_addr))
return EINVAL;
vr = map_copy_region(dvmp, region);
if(!vr)
return ENOMEM;
USE(vr,
vr->vaddr = startv;
vr->length = size;
vr->flags = region->flags;
vr->tag = VRT_NONE;
vr->parent = dvmp;);
vm_assert(vr->flags & VR_SHARED);
if (prev) {
USE(vr,
vr->next = prev->next;);
USE(prev, prev->next = vr;);
} else {
USE(vr,
vr->next = dvmp->vm_regions;);
dvmp->vm_regions = vr;
}
physr_start_iter_least(vr->phys, &iter);
while((ph = physr_get_iter(&iter))) {
struct phys_block *pb = ph->ph;
USE(pb, pb->refcount++;);
if(map_ph_writept(dvmp, vr, ph) != OK) {
vm_panic("map_remap: map_ph_writept failed", NO_NUM);
}
physr_incr_iter(&iter);
}
*r = startv;
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
/*========================================================================*
* map_get_phys *
*========================================================================*/
PUBLIC int map_get_phys(struct vmproc *vmp, vir_bytes addr, phys_bytes *r)
{
struct vir_region *vr;
struct phys_region *ph;
physr_iter iter;
if (!(vr = map_lookup(vmp, addr)) ||
(vr->vaddr != addr))
return EINVAL;
if (!(vr->flags & VR_SHARED))
return EINVAL;
physr_start_iter_least(vr->phys, &iter);
ph = physr_get_iter(&iter);
vm_assert(ph);
vm_assert(ph->ph);
if (r)
*r = ph->ph->phys;
return OK;
}
/*========================================================================*
* map_get_ref *
*========================================================================*/
PUBLIC int map_get_ref(struct vmproc *vmp, vir_bytes addr, u8_t *cnt)
{
struct vir_region *vr;
struct phys_region *ph;
physr_iter iter;
if (!(vr = map_lookup(vmp, addr)) ||
(vr->vaddr != addr))
return EINVAL;
if (!(vr->flags & VR_SHARED))
return EINVAL;
physr_start_iter_least(vr->phys, &iter);
ph = physr_get_iter(&iter);
vm_assert(ph);
vm_assert(ph->ph);
if (cnt)
*cnt = ph->ph->refcount;
return OK;
}
/*========================================================================*
* regionprintstats *
*========================================================================*/
PUBLIC void printregionstats(struct vmproc *vmp)
{
struct vir_region *vr;
struct phys_region *pr;
physr_iter iter;
vir_bytes used = 0, weighted = 0;
for(vr = vmp->vm_regions; vr; vr = vr->next) {
if(vr->flags & VR_DIRECT)
continue;
physr_start_iter_least(vr->phys, &iter);
while((pr = physr_get_iter(&iter))) {
physr_incr_iter(&iter);
used += pr->ph->length;
weighted += pr->ph->length / pr->ph->refcount;
}
}
printf("%6dkB %6dkB\n", used/1024, weighted/1024);
return;
}
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