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// Post memory manager (PMM) calls
//
// Copyright (C) 2009 Kevin O'Connor <kevin@koconnor.net>
//
// This file may be distributed under the terms of the GNU LGPLv3 license.
#include "util.h" // checksum
#include "config.h" // BUILD_BIOS_ADDR
#include "memmap.h" // find_high_area
#include "farptr.h" // GET_FARVAR
#include "biosvar.h" // GET_BDA
#if MODESEGMENT
// The 16bit pmm entry points runs in "big real" mode, and can
// therefore read/write to the 32bit malloc variables.
#define GET_PMMVAR(var) GET_FARVAR(0, (var))
#define SET_PMMVAR(var, val) SET_FARVAR(0, (var), (val))
#else
#define GET_PMMVAR(var) (var)
#define SET_PMMVAR(var, val) do { (var) = (val); } while (0)
#endif
// Zone definitions
struct zone_s {
u32 top, bottom, cur;
};
struct zone_s ZoneLow VAR32FLATVISIBLE, ZoneHigh VAR32FLATVISIBLE;
struct zone_s ZoneFSeg VAR32FLATVISIBLE;
struct zone_s ZoneTmpLow VAR32FLATVISIBLE, ZoneTmpHigh VAR32FLATVISIBLE;
struct zone_s *Zones[] VAR32FLATVISIBLE = {
&ZoneTmpLow, &ZoneLow, &ZoneFSeg, &ZoneTmpHigh, &ZoneHigh
};
/****************************************************************
* ebda movement
****************************************************************/
// Move ebda
static int
relocate_ebda(u32 newebda, u32 oldebda, u8 ebda_size)
{
u32 lowram = GET_BDA(mem_size_kb) * 1024;
if (oldebda != lowram)
// EBDA isn't at end of ram - give up.
return -1;
// Do copy
if (MODESEGMENT)
memcpy_far(FLATPTR_TO_SEG(newebda)
, (void*)FLATPTR_TO_OFFSET(newebda)
, FLATPTR_TO_SEG(oldebda)
, (void*)FLATPTR_TO_OFFSET(oldebda)
, ebda_size * 1024);
else
memmove((void*)newebda, (void*)oldebda, ebda_size * 1024);
// Update indexes
dprintf(1, "ebda moved from %x to %x\n", oldebda, newebda);
SET_BDA(mem_size_kb, newebda / 1024);
SET_BDA(ebda_seg, FLATPTR_TO_SEG(newebda));
return 0;
}
// Support expanding the ZoneLow dynamically.
static void
zonelow_expand(u32 size, u32 align)
{
u32 oldpos = GET_PMMVAR(ZoneLow.cur);
u32 newpos = ALIGN_DOWN(oldpos - size, align);
u32 bottom = GET_PMMVAR(ZoneLow.bottom);
if (newpos >= bottom && newpos <= oldpos)
// Space already present.
return;
u16 ebda_seg = get_ebda_seg();
u32 ebda_pos = (u32)MAKE_FLATPTR(ebda_seg, 0);
u8 ebda_size = GET_EBDA2(ebda_seg, size);
u32 ebda_end = ebda_pos + ebda_size * 1024;
if (ebda_end != bottom) {
// Something else is after ebda - can't use any existing space.
oldpos = ebda_end;
newpos = ALIGN_DOWN(oldpos - size, align);
}
u32 newbottom = ALIGN_DOWN(newpos, 1024);
u32 newebda = ALIGN_DOWN(newbottom - ebda_size * 1024, 1024);
if (newebda < BUILD_EBDA_MINIMUM)
// Not enough space.
return;
// Move ebda
int ret = relocate_ebda(newebda, ebda_pos, ebda_size);
if (ret)
return;
// Update zone
SET_PMMVAR(ZoneLow.cur, oldpos);
SET_PMMVAR(ZoneLow.bottom, newbottom);
}
/****************************************************************
* zone allocations
****************************************************************/
// Obtain memory from a given zone.
static void *
zone_malloc(struct zone_s *zone, u32 size, u32 align)
{
u32 oldpos = GET_PMMVAR(zone->cur);
u32 newpos = ALIGN_DOWN(oldpos - size, align);
if (newpos < GET_PMMVAR(zone->bottom) || newpos > oldpos)
// No space
return NULL;
SET_PMMVAR(zone->cur, newpos);
return (void*)newpos;
}
// Find the zone that contains the given data block.
static struct zone_s *
zone_find(void *data)
{
int i;
for (i=0; i<ARRAY_SIZE(Zones); i++) {
struct zone_s *zone = GET_PMMVAR(Zones[i]);
if ((u32)data >= GET_PMMVAR(zone->cur)
&& (u32)data < GET_PMMVAR(zone->top))
return zone;
}
return NULL;
}
// Return memory to a zone (if it was the last to be allocated).
static int
zone_free(void *data, u32 olddata)
{
struct zone_s *zone = zone_find(data);
if (!zone || !data || GET_PMMVAR(zone->cur) != (u32)data)
return -1;
SET_PMMVAR(zone->cur, olddata);
return 0;
}
// Report the status of all the zones.
static void
dumpZones()
{
int i;
for (i=0; i<ARRAY_SIZE(Zones); i++) {
struct zone_s *zone = Zones[i];
u32 used = zone->top - zone->cur;
u32 avail = zone->top - zone->bottom;
u32 pct = avail ? ((100 * used) / avail) : 0;
dprintf(2, "zone %d: %08x-%08x used=%d (%d%%)\n"
, i, zone->bottom, zone->top, used, pct);
}
}
/****************************************************************
* tracked memory allocations
****************************************************************/
// Information on PMM tracked allocations
struct pmmalloc_s {
void *data;
u32 olddata;
u32 handle;
u32 oldallocdata;
struct pmmalloc_s *next;
};
struct pmmalloc_s *PMMAllocs VAR32FLATVISIBLE;
// Allocate memory from the given zone and track it as a PMM allocation
void *
pmm_malloc(struct zone_s *zone, u32 handle, u32 size, u32 align)
{
u32 oldallocdata = GET_PMMVAR(ZoneTmpHigh.cur);
struct pmmalloc_s *info = zone_malloc(&ZoneTmpHigh, sizeof(*info)
, MALLOC_MIN_ALIGN);
if (!info) {
oldallocdata = GET_PMMVAR(ZoneTmpLow.cur);
info = zone_malloc(&ZoneTmpLow, sizeof(*info), MALLOC_MIN_ALIGN);
if (!info)
return NULL;
}
if (zone == &ZoneLow)
zonelow_expand(size, align);
u32 olddata = GET_PMMVAR(zone->cur);
void *data = zone_malloc(zone, size, align);
if (! data) {
zone_free(info, oldallocdata);
return NULL;
}
dprintf(8, "pmm_malloc zone=%p handle=%x size=%d align=%x"
" ret=%p (info=%p)\n"
, zone, handle, size, align
, data, info);
SET_PMMVAR(info->data, data);
SET_PMMVAR(info->olddata, olddata);
SET_PMMVAR(info->handle, handle);
SET_PMMVAR(info->oldallocdata, oldallocdata);
SET_PMMVAR(info->next, GET_PMMVAR(PMMAllocs));
SET_PMMVAR(PMMAllocs, info);
return data;
}
// Free a raw data block (either from a zone or from pmm alloc list).
static void
pmm_free_data(void *data, u32 olddata)
{
int ret = zone_free(data, olddata);
if (!ret)
// Success - done.
return;
struct pmmalloc_s *info;
for (info=GET_PMMVAR(PMMAllocs); info; info = GET_PMMVAR(info->next))
if (GET_PMMVAR(info->olddata) == (u32)data) {
SET_PMMVAR(info->olddata, olddata);
return;
} else if (GET_PMMVAR(info->oldallocdata) == (u32)data) {
SET_PMMVAR(info->oldallocdata, olddata);
return;
}
}
// Free a data block allocated with pmm_malloc
int
pmm_free(void *data)
{
struct pmmalloc_s **pinfo = &PMMAllocs;
for (;;) {
struct pmmalloc_s *info = GET_PMMVAR(*pinfo);
if (!info)
return -1;
if (GET_PMMVAR(info->data) == data) {
SET_PMMVAR(*pinfo, GET_PMMVAR(info->next));
u32 oldallocdata = GET_PMMVAR(info->oldallocdata);
u32 olddata = GET_PMMVAR(info->olddata);
pmm_free_data(data, olddata);
pmm_free_data(info, oldallocdata);
dprintf(8, "pmm_free data=%p olddata=%p oldallocdata=%p info=%p\n"
, data, (void*)olddata, (void*)oldallocdata, info);
return 0;
}
pinfo = &info->next;
}
}
// Find the amount of free space in a given zone.
static u32
pmm_getspace(struct zone_s *zone)
{
// XXX - doesn't account for ZoneLow being able to grow.
u32 space = GET_PMMVAR(zone->cur) - GET_PMMVAR(zone->bottom);
if (zone != &ZoneTmpHigh && zone != &ZoneTmpLow)
return space;
// Account for space needed for PMM tracking.
u32 reserve = ALIGN(sizeof(struct pmmalloc_s), MALLOC_MIN_ALIGN);
if (space <= reserve)
return 0;
return space - reserve;
}
// Find the data block allocated with pmm_malloc with a given handle.
static void *
pmm_find(u32 handle)
{
struct pmmalloc_s *info;
for (info=GET_PMMVAR(PMMAllocs); info; info = GET_PMMVAR(info->next))
if (GET_PMMVAR(info->handle) == handle)
return GET_PMMVAR(info->data);
return NULL;
}
void
malloc_setup()
{
ASSERT32FLAT();
dprintf(3, "malloc setup\n");
PMMAllocs = NULL;
// Memory in 0xf0000 area.
extern u8 code32_start[];
if ((u32)code32_start > BUILD_BIOS_ADDR)
// Clear unused parts of f-segment
memset((void*)BUILD_BIOS_ADDR, 0, (u32)code32_start - BUILD_BIOS_ADDR);
memset(BiosTableSpace, 0, CONFIG_MAX_BIOSTABLE);
ZoneFSeg.bottom = (u32)BiosTableSpace;
ZoneFSeg.top = ZoneFSeg.cur = ZoneFSeg.bottom + CONFIG_MAX_BIOSTABLE;
// Memory under 1Meg.
ZoneTmpLow.bottom = BUILD_STACK_ADDR;
ZoneTmpLow.top = ZoneTmpLow.cur = BUILD_EBDA_MINIMUM;
// Permanent memory under 1Meg.
ZoneLow.bottom = ZoneLow.top = ZoneLow.cur = BUILD_LOWRAM_END;
// Find memory at the top of ram.
struct e820entry *e = find_high_area(CONFIG_MAX_HIGHTABLE+MALLOC_MIN_ALIGN);
if (!e) {
// No memory above 1Meg
memset(&ZoneHigh, 0, sizeof(ZoneHigh));
memset(&ZoneTmpHigh, 0, sizeof(ZoneTmpHigh));
return;
}
u32 top = e->start + e->size, bottom = e->start;
// Memory at top of ram.
ZoneHigh.bottom = ALIGN(top - CONFIG_MAX_HIGHTABLE, MALLOC_MIN_ALIGN);
ZoneHigh.top = ZoneHigh.cur = ZoneHigh.bottom + CONFIG_MAX_HIGHTABLE;
add_e820(ZoneHigh.bottom, CONFIG_MAX_HIGHTABLE, E820_RESERVED);
// Memory above 1Meg
ZoneTmpHigh.bottom = ALIGN(bottom, MALLOC_MIN_ALIGN);
ZoneTmpHigh.top = ZoneTmpHigh.cur = ZoneHigh.bottom;
}
void
malloc_finalize()
{
dprintf(3, "malloc finalize\n");
dumpZones();
// Reserve more low-mem if needed.
u32 endlow = GET_BDA(mem_size_kb)*1024;
add_e820(endlow, BUILD_LOWRAM_END-endlow, E820_RESERVED);
// Give back unused high ram.
u32 giveback = ALIGN_DOWN(ZoneHigh.cur - ZoneHigh.bottom, PAGE_SIZE);
add_e820(ZoneHigh.bottom, giveback, E820_RAM);
dprintf(1, "Returned %d bytes of ZoneHigh\n", giveback);
// Clear low-memory allocations.
memset((void*)ZoneTmpLow.bottom, 0, ZoneTmpLow.top - ZoneTmpLow.bottom);
}
/****************************************************************
* pmm interface
****************************************************************/
struct pmmheader {
u32 signature;
u8 version;
u8 length;
u8 checksum;
u16 entry_offset;
u16 entry_seg;
u8 reserved[5];
} PACKED;
extern struct pmmheader PMMHEADER;
#define PMM_SIGNATURE 0x4d4d5024 // $PMM
#if CONFIG_PMM
struct pmmheader PMMHEADER __aligned(16) VAR16EXPORT = {
.version = 0x01,
.length = sizeof(PMMHEADER),
.entry_seg = SEG_BIOS,
};
#endif
#define PMM_FUNCTION_NOT_SUPPORTED 0xffffffff
// PMM - allocate
static u32
handle_pmm00(u16 *args)
{
u32 length = *(u32*)&args[1], handle = *(u32*)&args[3];
u16 flags = args[5];
dprintf(3, "pmm00: length=%x handle=%x flags=%x\n"
, length, handle, flags);
struct zone_s *lowzone = &ZoneTmpLow, *highzone = &ZoneTmpHigh;
if (flags & 8) {
// Permanent memory request.
lowzone = &ZoneLow;
highzone = &ZoneHigh;
}
if (!length) {
// Memory size request
switch (flags & 3) {
default:
case 0:
return 0;
case 1:
return pmm_getspace(lowzone);
case 2:
return pmm_getspace(highzone);
case 3: {
u32 spacelow = pmm_getspace(lowzone);
u32 spacehigh = pmm_getspace(highzone);
if (spacelow > spacehigh)
return spacelow;
return spacehigh;
}
}
}
u32 size = length * 16;
if ((s32)size <= 0)
return 0;
u32 align = MALLOC_MIN_ALIGN;
if (flags & 4) {
align = 1<<__ffs(size);
if (align < MALLOC_MIN_ALIGN)
align = MALLOC_MIN_ALIGN;
}
switch (flags & 3) {
default:
case 0:
return 0;
case 1:
return (u32)pmm_malloc(lowzone, handle, size, align);
case 2:
return (u32)pmm_malloc(highzone, handle, size, align);
case 3: {
void *data = pmm_malloc(lowzone, handle, size, align);
if (data)
return (u32)data;
return (u32)pmm_malloc(highzone, handle, size, align);
}
}
}
// PMM - find
static u32
handle_pmm01(u16 *args)
{
u32 handle = *(u32*)&args[1];
dprintf(3, "pmm01: handle=%x\n", handle);
if (handle == PMM_DEFAULT_HANDLE)
return 0;
return (u32)pmm_find(handle);
}
// PMM - deallocate
static u32
handle_pmm02(u16 *args)
{
u32 buffer = *(u32*)&args[1];
dprintf(3, "pmm02: buffer=%x\n", buffer);
int ret = pmm_free((void*)buffer);
if (ret)
// Error
return 1;
return 0;
}
static u32
handle_pmmXX(u16 *args)
{
return PMM_FUNCTION_NOT_SUPPORTED;
}
u32 VISIBLE16
handle_pmm(u16 *args)
{
if (! CONFIG_PMM)
return PMM_FUNCTION_NOT_SUPPORTED;
u16 arg1 = args[0];
dprintf(DEBUG_HDL_pmm, "pmm call arg1=%x\n", arg1);
switch (arg1) {
case 0x00: return handle_pmm00(args);
case 0x01: return handle_pmm01(args);
case 0x02: return handle_pmm02(args);
default: return handle_pmmXX(args);
}
}
// romlayout.S
extern void entry_pmm();
void
pmm_setup()
{
if (! CONFIG_PMM)
return;
dprintf(3, "init PMM\n");
PMMHEADER.signature = PMM_SIGNATURE;
PMMHEADER.entry_offset = (u32)entry_pmm - BUILD_BIOS_ADDR;
PMMHEADER.checksum -= checksum(&PMMHEADER, sizeof(PMMHEADER));
}
void
pmm_finalize()
{
if (! CONFIG_PMM)
return;
dprintf(3, "finalize PMM\n");
PMMHEADER.signature = 0;
PMMHEADER.entry_offset = 0;
}