cosmopolitan/tool/build/lib/memory.c

285 lines
8.6 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/assert.h"
#include "libc/log/check.h"
#include "libc/log/log.h"
#include "libc/macros.h"
#include "libc/mem/mem.h"
#include "libc/str/str.h"
#include "libc/x/x.h"
#include "tool/build/lib/endian.h"
#include "tool/build/lib/machine.h"
#include "tool/build/lib/memory.h"
#include "tool/build/lib/pml4t.h"
#include "tool/build/lib/stats.h"
#include "tool/build/lib/throw.h"
void SetReadAddr(struct Machine *m, int64_t addr, uint32_t size) {
if (size) {
m->readaddr = addr;
m->readsize = size;
}
}
void SetWriteAddr(struct Machine *m, int64_t addr, uint32_t size) {
if (size) {
m->writeaddr = addr;
m->writesize = size;
}
}
long HandlePageFault(struct Machine *m, uint64_t entry, uint64_t table,
unsigned index) {
long page;
if ((page = AllocateLinearPage(m)) != -1) {
--m->memstat.reserved;
*(uint64_t *)(m->real.p + table + index * 8) =
page | entry & ~0x7ffffffffe00;
}
return page;
}
void *FindReal(struct Machine *m, int64_t virt) {
long page;
uint64_t table, entry;
unsigned skew, level, index, i;
if ((m->mode & 3) != XED_MODE_REAL) {
if (-0x800000000000 <= virt && virt < 0x800000000000) {
skew = virt & 0xfff;
virt &= -0x1000;
for (i = 0; i < ARRAYLEN(m->tlb); ++i) {
if (m->tlb[i].virt == virt && m->tlb[i].host) {
return m->tlb[i].host + skew;
}
}
level = 39;
entry = m->cr3;
do {
table = entry & 0x7ffffffff000;
CHECK_LT(table, m->real.n);
index = (virt >> level) & 511;
entry = *(uint64_t *)(m->real.p + table + index * 8);
if (!(entry & 1)) return NULL;
} while ((level -= 9) >= 12);
if (!(entry & 0x0e00)) {
page = entry & 0x7ffffffff000;
CHECK_LT(page, m->real.n);
} else if ((page = HandlePageFault(m, entry, table, index)) == -1) {
return NULL;
}
m->tlbindex = (m->tlbindex + 1) & (ARRAYLEN(m->tlb) - 1);
m->tlb[m->tlbindex] = m->tlb[0];
m->tlb[0].virt = virt;
m->tlb[0].host = m->real.p + page;
return m->real.p + page + skew;
} else {
return NULL;
}
} else if (0 <= virt && virt + 0xfff < m->real.n) {
return m->real.p + virt;
} else {
return NULL;
}
}
void *ResolveAddress(struct Machine *m, int64_t v) {
void *r;
if ((r = FindReal(m, v))) return r;
ThrowSegmentationFault(m, v);
}
void VirtualSet(struct Machine *m, int64_t v, char c, uint64_t n) {
char *p;
uint64_t k;
k = 0x1000 - (v & 0xfff);
while (n) {
k = MIN(k, n);
p = ResolveAddress(m, v);
memset(p, c, k);
n -= k;
v += k;
k = 0x1000;
}
}
void VirtualCopy(struct Machine *m, int64_t v, char *r, uint64_t n, bool d) {
char *p;
uint64_t k;
k = 0x1000 - (v & 0xfff);
while (n) {
k = MIN(k, n);
p = ResolveAddress(m, v);
if (d) {
memcpy(r, p, k);
} else {
memcpy(p, r, k);
}
n -= k;
r += k;
v += k;
k = 0x1000;
}
}
void *VirtualSend(struct Machine *m, void *dst, int64_t src, uint64_t n) {
VirtualCopy(m, src, dst, n, true);
return dst;
}
void VirtualSendRead(struct Machine *m, void *dst, int64_t addr, uint64_t n) {
VirtualSend(m, dst, addr, n);
SetReadAddr(m, addr, n);
}
void VirtualRecv(struct Machine *m, int64_t dst, void *src, uint64_t n) {
VirtualCopy(m, dst, src, n, false);
}
void VirtualRecvWrite(struct Machine *m, int64_t addr, void *src, uint64_t n) {
VirtualRecv(m, addr, src, n);
SetWriteAddr(m, addr, n);
}
void *ReserveAddress(struct Machine *m, int64_t v, size_t n) {
void *r;
DCHECK_LE(n, sizeof(m->stash));
if ((v & 0xfff) + n <= 0x1000) return ResolveAddress(m, v);
m->stashaddr = v;
m->stashsize = n;
r = m->stash;
VirtualSend(m, r, v, n);
return r;
}
void *AccessRam(struct Machine *m, int64_t v, size_t n, void *p[2],
uint8_t *tmp, bool copy) {
unsigned k;
uint8_t *a, *b;
DCHECK_LE(n, 0x1000);
if ((v & 0xfff) + n <= 0x1000) return ResolveAddress(m, v);
k = 0x1000;
k -= v & 0xfff;
DCHECK_LE(k, 0x1000);
a = ResolveAddress(m, v);
b = ResolveAddress(m, v + k);
if (copy) {
memcpy(tmp, a, k);
memcpy(tmp + k, b, n - k);
}
p[0] = a;
p[1] = b;
return tmp;
}
void *Load(struct Machine *m, int64_t v, size_t n, uint8_t *b) {
void *p[2];
SetReadAddr(m, v, n);
return AccessRam(m, v, n, p, b, true);
}
void *BeginStore(struct Machine *m, int64_t v, size_t n, void *p[2],
uint8_t *b) {
SetWriteAddr(m, v, n);
return AccessRam(m, v, n, p, b, false);
}
void *BeginStoreNp(struct Machine *m, int64_t v, size_t n, void *p[2],
uint8_t *b) {
if (!v) return NULL;
return BeginStore(m, v, n, p, b);
}
void *BeginLoadStore(struct Machine *m, int64_t v, size_t n, void *p[2],
uint8_t *b) {
SetWriteAddr(m, v, n);
return AccessRam(m, v, n, p, b, true);
}
void EndStore(struct Machine *m, int64_t v, size_t n, void *p[2], uint8_t *b) {
uint8_t *a;
unsigned k;
DCHECK_LE(n, 0x1000);
if ((v & 0xfff) + n <= 0x1000) return;
k = 0x1000;
k -= v & 0xfff;
DCHECK_GT(k, n);
DCHECK_NOTNULL(p[0]);
DCHECK_NOTNULL(p[1]);
memcpy(p[0], b, k);
memcpy(p[1], b + k, n - k);
}
void EndStoreNp(struct Machine *m, int64_t v, size_t n, void *p[2],
uint8_t *b) {
if (v) EndStore(m, v, n, p, b);
}
void *LoadStr(struct Machine *m, int64_t addr) {
size_t have;
char *copy, *page, *p;
have = 0x1000 - (addr & 0xfff);
if (!addr) return NULL;
if (!(page = FindReal(m, addr))) return NULL;
if ((p = memchr(page, '\0', have))) {
SetReadAddr(m, addr, p - page + 1);
return page;
}
CHECK_LT(m->freelist.i, ARRAYLEN(m->freelist.p));
if (!(copy = malloc(have + 0x1000))) return NULL;
memcpy(copy, page, have);
for (;;) {
if (!(page = FindReal(m, addr + have))) break;
if ((p = memccpy(copy + have, page, '\0', 0x1000))) {
SetReadAddr(m, addr, have + (p - (copy + have)) + 1);
return (m->freelist.p[m->freelist.i++] = copy);
}
have += 0x1000;
if (!(p = realloc(copy, have + 0x1000))) break;
copy = p;
}
free(copy);
return NULL;
}
void *LoadBuf(struct Machine *m, int64_t addr, size_t size) {
size_t have, need;
char *buf, *copy, *page;
have = 0x1000 - (addr & 0xfff);
if (!addr) return NULL;
if (!(buf = FindReal(m, addr))) return NULL;
if (size > have) {
CHECK_LT(m->freelist.i, ARRAYLEN(m->freelist.p));
if (!(copy = malloc(size))) return NULL;
buf = memcpy(copy, buf, have);
do {
need = MIN(0x1000, size - have);
if ((page = FindReal(m, addr + have))) {
memcpy(copy + have, page, need);
have += need;
} else {
free(copy);
return NULL;
}
} while (have < size);
}
SetReadAddr(m, addr, size);
return buf;
}