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- /*
- * Size memory and create the kernel page-tables on the fly while doing so.
- * Called from main(), this code should only be run by the bootstrap processor.
- */
- #include "u.h"
- #include "lib.h"
- #include "mem.h"
- #include "dat.h"
- #include "fns.h"
- #include "io.h"
- #define MEMDEBUG 0
- #define PDX(va) ((((ulong)(va))>>22) & 0x03FF)
- #define PTX(va) ((((ulong)(va))>>12) & 0x03FF)
- enum {
- MemUPA = 0, /* unbacked physical address */
- MemRAM = 1, /* physical memory */
- MemUMB = 2, /* upper memory block (<16MB) */
- NMemType = 3,
- KB = 1024,
- MemMinMB = 4, /* minimum physical memory (<=4MB) */
- MemMaxMB = 768, /* maximum physical memory to check */
- NMemBase = 10,
- };
- typedef struct {
- int size;
- ulong addr;
- } Map;
- typedef struct {
- char* name;
- Map* map;
- Map* mapend;
- Lock;
- } RMap;
- static Map mapupa[8];
- static RMap rmapupa = {
- "unallocated unbacked physical memory",
- mapupa,
- &mapupa[7],
- };
- static Map xmapupa[8];
- static RMap xrmapupa = {
- "unbacked physical memory",
- xmapupa,
- &xmapupa[7],
- };
- static Map mapram[8];
- static RMap rmapram = {
- "physical memory",
- mapram,
- &mapram[7],
- };
- static Map mapumb[64];
- static RMap rmapumb = {
- "upper memory block",
- mapumb,
- &mapumb[63],
- };
- static Map mapumbrw[8];
- static RMap rmapumbrw = {
- "UMB device memory",
- mapumbrw,
- &mapumbrw[7],
- };
- void
- memdebug(void)
- {
- Map *mp;
- ulong maxpa, maxpa1, maxpa2;
- if(MEMDEBUG == 0)
- return;
- maxpa = (nvramread(0x18)<<8)|nvramread(0x17);
- maxpa1 = (nvramread(0x31)<<8)|nvramread(0x30);
- maxpa2 = (nvramread(0x16)<<8)|nvramread(0x15);
- print("maxpa = %luX -> %luX, maxpa1 = %luX maxpa2 = %luX\n",
- maxpa, MB+maxpa*KB, maxpa1, maxpa2);
- for(mp = rmapram.map; mp->size; mp++)
- print("%8.8luX %8.8luX %8.8luX\n", mp->addr, (ulong)mp->size, mp->addr+mp->size);
- for(mp = rmapumb.map; mp->size; mp++)
- print("%8.8luX %8.8luX %8.8luX\n", mp->addr, (ulong)mp->size, mp->addr+mp->size);
- for(mp = rmapumbrw.map; mp->size; mp++)
- print("%8.8luX %8.8luX %8.8luX\n", mp->addr, (ulong)mp->size, mp->addr+mp->size);
- for(mp = rmapupa.map; mp->size; mp++)
- print("%8.8luX %8.8luX %8.8luX\n", mp->addr, (ulong)mp->size, mp->addr+mp->size);
- }
- void
- mapfree(RMap* rmap, ulong addr, ulong size)
- {
- Map *mp;
- ulong t;
- if(size == 0)
- return;
- lock(rmap);
- for(mp = rmap->map; mp->addr <= addr && mp->size; mp++)
- ;
- if(mp > rmap->map && (mp-1)->addr+(mp-1)->size == addr){
- (mp-1)->size += size;
- if(addr+size == mp->addr){
- (mp-1)->size += mp->size;
- while(mp->size){
- mp++;
- (mp-1)->addr = mp->addr;
- (mp-1)->size = mp->size;
- }
- }
- }
- else{
- if(addr+size == mp->addr && mp->size){
- mp->addr -= size;
- mp->size += size;
- }
- else do{
- if(mp >= rmap->mapend){
- print("mapfree: %s: losing 0x%luX, %lud\n",
- rmap->name, addr, size);
- break;
- }
- t = mp->addr;
- mp->addr = addr;
- addr = t;
- t = mp->size;
- mp->size = size;
- mp++;
- }while(size = t);
- }
- unlock(rmap);
- }
- ulong
- mapalloc(RMap* rmap, ulong addr, int size, int align)
- {
- Map *mp;
- ulong maddr, oaddr;
- lock(rmap);
- for(mp = rmap->map; mp->size; mp++){
- maddr = mp->addr;
- if(addr){
- /*
- * A specific address range has been given:
- * if the current map entry is greater then
- * the address is not in the map;
- * if the current map entry does not overlap
- * the beginning of the requested range then
- * continue on to the next map entry;
- * if the current map entry does not entirely
- * contain the requested range then the range
- * is not in the map.
- */
- if(maddr > addr)
- break;
- if(mp->size < addr - maddr) /* maddr+mp->size < addr, but no overflow */
- continue;
- if(addr - maddr > mp->size - size) /* addr+size > maddr+mp->size, but no overflow */
- break;
- maddr = addr;
- }
- if(align > 0)
- maddr = ((maddr+align-1)/align)*align;
- if(mp->addr+mp->size-maddr < size)
- continue;
- oaddr = mp->addr;
- mp->addr = maddr+size;
- mp->size -= maddr-oaddr+size;
- if(mp->size == 0){
- do{
- mp++;
- (mp-1)->addr = mp->addr;
- }while((mp-1)->size = mp->size);
- }
- unlock(rmap);
- if(oaddr != maddr)
- mapfree(rmap, oaddr, maddr-oaddr);
- return maddr;
- }
- unlock(rmap);
- return 0;
- }
- static void
- umbscan(void)
- {
- uchar *p;
- /*
- * Scan the Upper Memory Blocks (0xA0000->0xF0000) for pieces
- * which aren't used; they can be used later for devices which
- * want to allocate some virtual address space.
- * Check for two things:
- * 1) device BIOS ROM. This should start with a two-byte header
- * of 0x55 0xAA, followed by a byte giving the size of the ROM
- * in 512-byte chunks. These ROM's must start on a 2KB boundary.
- * 2) device memory. This is read-write.
- * There are some assumptions: there's VGA memory at 0xA0000 and
- * the VGA BIOS ROM is at 0xC0000. Also, if there's no ROM signature
- * at 0xE0000 then the whole 64KB up to 0xF0000 is theoretically up
- * for grabs; check anyway.
- */
- p = KADDR(0xD0000); /*RSC: changed from 0xC0000 */
- while(p < (uchar*)KADDR(0xE0000)){
- if (p[0] == 0x55 && p[1] == 0xAA) {
- /* Skip p[2] chunks of 512 bytes. Test for 0x55 AA before
- poking obtrusively, or else the Thinkpad X20 dies when
- setting up the cardbus (PB) */
- p += p[2] * 512;
- continue;
- }
- p[0] = 0xCC;
- p[2*KB-1] = 0xCC;
- if(p[0] != 0xCC || p[2*KB-1] != 0xCC){
- p[0] = 0x55;
- p[1] = 0xAA;
- p[2] = 4;
- if(p[0] == 0x55 && p[1] == 0xAA){
- p += p[2]*512;
- continue;
- }
- if(p[0] == 0xFF && p[1] == 0xFF)
- mapfree(&rmapumb, PADDR(p), 2*KB);
- }
- else
- mapfree(&rmapumbrw, PADDR(p), 2*KB);
- p += 2*KB;
- }
- p = KADDR(0xE0000);
- if(p[0] != 0x55 || p[1] != 0xAA){
- p[0] = 0xCC;
- p[64*KB-1] = 0xCC;
- if(p[0] != 0xCC && p[64*KB-1] != 0xCC)
- mapfree(&rmapumb, PADDR(p), 64*KB);
- }
- }
- void
- meminit(ulong)
- {
- /* A hack to initialize unbacked physical memory. It's assumed PCI space is assigned by
- the BIOS in the 0xF0000000 range and 9load never needs more than 0x2000... to run. These
- values leave ample space for memory allocations for uninitialized PCI cards (e.g. cardbus
- cards). (pb) */
- ulong maxmem = 0x40000000;
- umbscan();
- mapfree(&rmapupa, maxmem, 0x00000000-maxmem);
- if(MEMDEBUG)
- memdebug();
- }
- ulong
- umbmalloc(ulong addr, int size, int align)
- {
- ulong a;
- if(a = mapalloc(&rmapumb, addr, size, align))
- return (ulong)KADDR(a);
- return 0;
- }
- void
- umbfree(ulong addr, int size)
- {
- mapfree(&rmapumb, PADDR(addr), size);
- }
- ulong
- umbrwmalloc(ulong addr, int size, int align)
- {
- ulong a;
- uchar *p;
- if(a = mapalloc(&rmapumbrw, addr, size, align))
- return(ulong)KADDR(a);
- /*
- * Perhaps the memory wasn't visible before
- * the interface is initialised, so try again.
- */
- if((a = umbmalloc(addr, size, align)) == 0)
- return 0;
- p = (uchar*)a;
- p[0] = 0xCC;
- p[size-1] = 0xCC;
- if(p[0] == 0xCC && p[size-1] == 0xCC)
- return a;
- umbfree(a, size);
- return 0;
- }
- void
- umbrwfree(ulong addr, int size)
- {
- mapfree(&rmapumbrw, PADDR(addr), size);
- }
- ulong*
- mmuwalk(ulong* pdb, ulong va, int level, int create)
- {
- ulong pa, *table;
- /*
- * Walk the page-table pointed to by pdb and return a pointer
- * to the entry for virtual address va at the requested level.
- * If the entry is invalid and create isn't requested then bail
- * out early. Otherwise, for the 2nd level walk, allocate a new
- * page-table page and register it in the 1st level.
- */
- table = &pdb[PDX(va)];
- if(!(*table & PTEVALID) && create == 0)
- return 0;
- switch(level){
- default:
- return 0;
- case 1:
- return table;
- case 2:
- if(*table & PTESIZE)
- panic("mmuwalk2: va 0x%ux entry 0x%ux", va, *table);
- if(!(*table & PTEVALID)){
- pa = PADDR(ialloc(BY2PG, BY2PG));
- *table = pa|PTEWRITE|PTEVALID;
- }
- table = KADDR(PPN(*table));
- return &table[PTX(va)];
- }
- }
- static Lock mmukmaplock;
- ulong
- mmukmap(ulong pa, ulong va, int size)
- {
- ulong pae, *table, *pdb, pgsz, *pte, x;
- int pse, sync;
- extern int cpuidax, cpuiddx;
- pdb = KADDR(getcr3());
- if((cpuiddx & 0x08) && (getcr4() & 0x10))
- pse = 1;
- else
- pse = 0;
- sync = 0;
- pa = PPN(pa);
- if(va == 0)
- va = (ulong)KADDR(pa);
- else
- va = PPN(va);
- pae = pa + size;
- lock(&mmukmaplock);
- while(pa < pae){
- table = &pdb[PDX(va)];
- /*
- * Possibly already mapped.
- */
- if(*table & PTEVALID){
- if(*table & PTESIZE){
- /*
- * Big page. Does it fit within?
- * If it does, adjust pgsz so the correct end can be
- * returned and get out.
- * If not, adjust pgsz up to the next 4MB boundary
- * and continue.
- */
- x = PPN(*table);
- if(x != pa)
- panic("mmukmap1: pa 0x%ux entry 0x%ux",
- pa, *table);
- x += 4*MB;
- if(pae <= x){
- pa = pae;
- break;
- }
- pgsz = x - pa;
- pa += pgsz;
- va += pgsz;
- continue;
- }
- else{
- /*
- * Little page. Walk to the entry.
- * If the entry is valid, set pgsz and continue.
- * If not, make it so, set pgsz, sync and continue.
- */
- pte = mmuwalk(pdb, va, 2, 0);
- if(pte && *pte & PTEVALID){
- x = PPN(*pte);
- if(x != pa)
- panic("mmukmap2: pa 0x%ux entry 0x%ux",
- pa, *pte);
- pgsz = BY2PG;
- pa += pgsz;
- va += pgsz;
- sync++;
- continue;
- }
- }
- }
- /*
- * Not mapped. Check if it can be mapped using a big page -
- * starts on a 4MB boundary, size >= 4MB and processor can do it.
- * If not a big page, walk the walk, talk the talk.
- * Sync is set.
- */
- if(pse && (pa % (4*MB)) == 0 && (pae >= pa+4*MB)){
- *table = pa|PTESIZE|PTEWRITE|PTEUNCACHED|PTEVALID;
- pgsz = 4*MB;
- }
- else{
- pte = mmuwalk(pdb, va, 2, 1);
- *pte = pa|PTEWRITE|PTEUNCACHED|PTEVALID;
- pgsz = BY2PG;
- }
- pa += pgsz;
- va += pgsz;
- sync++;
- }
- unlock(&mmukmaplock);
- /*
- * If something was added
- * then need to sync up.
- */
- if(sync)
- putcr3(PADDR(pdb));
- return pa;
- }
- ulong
- upamalloc(ulong addr, int size, int align)
- {
- ulong ae, a;
- USED(align);
- if((a = mapalloc(&rmapupa, addr, size, align)) == 0){
- memdebug();
- return 0;
- }
- /*
- * This is a travesty, but they all are.
- */
- ae = mmukmap(a, 0, size);
- /*
- * Should check here that it was all delivered
- * and put it back and barf if not.
- */
- USED(ae);
- /*
- * Be very careful this returns a PHYSICAL address.
- */
- return a;
- }
- void
- upafree(ulong pa, int size)
- {
- USED(pa, size);
- }
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