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minix/kernel/arch/i386/memory.c
Tomas Hruby ebbce7507b Complete ovehaul of mode switching code 
- after a trap to kernel, the code automatically switches to kernel
  stack, in the future local to the CPU

- k_reenter variable replaced by a test whether the CS is kernel cs or
  not. The information is passed further if needed. Removes a global
  variable which would need to be cpu local

- no need for global variables describing the exception or trap
  context. This information is kept on stack and a pointer to this
  structure is passed to the C code as a single structure

- removed loadedcr3 variable and its use replaced by reading the %cr3
  register

- no need to redisable interrupts in restart() as they are already
  disabled.

- unified handling of traps that push and don't push errorcode

- removed save() function as the process context is not saved directly
  to process table but saved as required by the trap code. Essentially
  it means that save() code is inlined everywhere not only in the
  exception handling routine

- returning from syscall is more arch independent - it sets the retger
  in C

- top of the x86 stack contains the current CPU id and pointer to the
  currently scheduled process (the one right interrupted) so the mode
  switch code can find where to save the context without need to use
  proc_ptr which will be cpu local in the future and therefore
  difficult to access in assembler and expensive to access in general

- some more clean up of level0 code. No need to read-back the argument
  passed in
  %eax from the proc structure. The mode switch code does not clobber
  %the general registers and hence we can just call what is in %eax

- many assebly macros in sconst.h as they will be reused by the apic
  assembly
2009-11-06 09:08:26 +00:00

1031 lines
27 KiB
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#include "../../kernel.h"
#include "../../proc.h"
#include "../../vm.h"
#include <minix/type.h>
#include <minix/syslib.h>
#include <minix/sysutil.h>
#include <minix/cpufeature.h>
#include <string.h>
#include <sys/vm_i386.h>
#include <minix/portio.h>
#include "proto.h"
#include "../../proto.h"
#include "../../proto.h"
#include "../../debug.h"
PRIVATE int psok = 0;
#define PROCPDEPTR(pr, pi) ((u32_t *) ((u8_t *) vm_pagedirs +\
I386_PAGE_SIZE * pr->p_nr + \
I386_VM_PT_ENT_SIZE * pi))
u8_t *vm_pagedirs = NULL;
#define NOPDE -1
#define PDEMASK(n) (1L << (n))
PUBLIC u32_t dirtypde;
#define WANT_FREEPDES (sizeof(dirtypde)*8-5)
PRIVATE int nfreepdes = 0, freepdes[WANT_FREEPDES], inusepde = NOPDE;
#define HASPT(procptr) ((procptr)->p_seg.p_cr3 != 0)
FORWARD _PROTOTYPE( u32_t phys_get32, (vir_bytes v) );
FORWARD _PROTOTYPE( void vm_enable_paging, (void) );
FORWARD _PROTOTYPE( void set_cr3, (void) );
/* *** Internal VM Functions *** */
PUBLIC void vm_init(struct proc *newptproc)
{
int i;
if(vm_running)
minix_panic("vm_init: vm_running", NO_NUM);
vm_set_cr3(newptproc);
level0(vm_enable_paging);
vm_running = 1;
}
#define TYPEDIRECT 0
#define TYPEPROCMAP 1
#define TYPEPHYS 2
/* This macro sets up a mapping from within the kernel's address
* space to any other area of memory, either straight physical
* memory (PROC == NULL) or a process view of memory, in 4MB chunks.
* It recognizes PROC having kernel address space as a special case.
*
* It sets PTR to the pointer within kernel address space at the start
* of the 4MB chunk, and OFFSET to the offset within that chunk
* that corresponds to LINADDR.
*
* It needs FREEPDE (available and addressable PDE within kernel
* address space), SEG (hardware segment), VIRT (in-datasegment
* address if known).
*/
#define CREATEPDE(PROC, PTR, LINADDR, REMAIN, BYTES, PDE, TYPE) { \
u32_t *pdeptr = NULL; \
int proc_pde_index; \
proc_pde_index = I386_VM_PDE(LINADDR); \
PDE = NOPDE; \
if((PROC) && (((PROC) == ptproc) || !HASPT(PROC))) { \
PTR = LINADDR; \
TYPE = TYPEDIRECT; \
} else { \
int fp; \
int mustinvl; \
u32_t pdeval, *pdevalptr, mask; \
phys_bytes offset; \
vmassert(psok); \
if(PROC) { \
TYPE = TYPEPROCMAP; \
vmassert(!iskernelp(PROC)); \
vmassert(HASPT(PROC)); \
pdeptr = PROCPDEPTR(PROC, proc_pde_index); \
pdeval = *pdeptr; \
} else { \
TYPE = TYPEPHYS; \
pdeval = (LINADDR & I386_VM_ADDR_MASK_4MB) | \
I386_VM_BIGPAGE | I386_VM_PRESENT | \
I386_VM_WRITE | I386_VM_USER; \
} \
for(fp = 0; fp < nfreepdes; fp++) { \
int k = freepdes[fp]; \
if(inusepde == k) \
continue; \
*PROCPDEPTR(ptproc, k) = 0; \
PDE = k; \
vmassert(k >= 0); \
vmassert(k < sizeof(dirtypde)*8); \
mask = PDEMASK(PDE); \
if(dirtypde & mask) \
continue; \
break; \
} \
vmassert(PDE != NOPDE); \
vmassert(mask); \
if(dirtypde & mask) { \
mustinvl = 1; \
} else { \
mustinvl = 0; \
} \
inusepde = PDE; \
*PROCPDEPTR(ptproc, PDE) = pdeval; \
offset = LINADDR & I386_VM_OFFSET_MASK_4MB; \
PTR = I386_BIG_PAGE_SIZE*PDE + offset; \
REMAIN = MIN(REMAIN, I386_BIG_PAGE_SIZE - offset); \
if(1 || mustinvl) { \
level0(reload_cr3); \
} \
} \
}
#define DONEPDE(PDE) { \
if(PDE != NOPDE) { \
vmassert(PDE > 0); \
vmassert(PDE < sizeof(dirtypde)*8); \
dirtypde |= PDEMASK(PDE); \
} \
}
#define WIPEPDE(PDE) { \
if(PDE != NOPDE) { \
vmassert(PDE > 0); \
vmassert(PDE < sizeof(dirtypde)*8); \
*PROCPDEPTR(ptproc, PDE) = 0; \
} \
}
/*===========================================================================*
* lin_lin_copy *
*===========================================================================*/
int lin_lin_copy(struct proc *srcproc, vir_bytes srclinaddr,
struct proc *dstproc, vir_bytes dstlinaddr, vir_bytes bytes)
{
u32_t addr;
int o1, o2;
int procslot;
int firstloop = 1;
NOREC_ENTER(linlincopy);
vmassert(vm_running);
vmassert(nfreepdes >= 3);
vmassert(ptproc);
vmassert(proc_ptr);
vmassert(read_cr3() == ptproc->p_seg.p_cr3);
procslot = ptproc->p_nr;
vmassert(procslot >= 0 && procslot < I386_VM_DIR_ENTRIES);
while(bytes > 0) {
phys_bytes srcptr, dstptr;
vir_bytes chunk = bytes;
int srcpde, dstpde;
int srctype, dsttype;
/* Set up 4MB ranges. */
inusepde = NOPDE;
CREATEPDE(srcproc, srcptr, srclinaddr, chunk, bytes, srcpde, srctype);
CREATEPDE(dstproc, dstptr, dstlinaddr, chunk, bytes, dstpde, dsttype);
/* Copy pages. */
PHYS_COPY_CATCH(srcptr, dstptr, chunk, addr);
DONEPDE(srcpde);
DONEPDE(dstpde);
if(addr) {
/* If addr is nonzero, a page fault was caught. */
if(addr >= srcptr && addr < (srcptr + chunk)) {
WIPEPDE(srcpde);
WIPEPDE(dstpde);
NOREC_RETURN(linlincopy, EFAULT_SRC);
}
if(addr >= dstptr && addr < (dstptr + chunk)) {
WIPEPDE(srcpde);
WIPEPDE(dstpde);
NOREC_RETURN(linlincopy, EFAULT_DST);
}
minix_panic("lin_lin_copy fault out of range", NO_NUM);
/* Not reached. */
NOREC_RETURN(linlincopy, EFAULT);
}
WIPEPDE(srcpde);
WIPEPDE(dstpde);
/* Update counter and addresses for next iteration, if any. */
bytes -= chunk;
srclinaddr += chunk;
dstlinaddr += chunk;
firstloop = 0;
}
NOREC_RETURN(linlincopy, OK);
}
PRIVATE u32_t phys_get32(addr)
phys_bytes addr;
{
u32_t v;
int r;
if(!vm_running) {
phys_copy(addr, vir2phys(&v), sizeof(v));
return v;
}
if((r=lin_lin_copy(NULL, addr,
proc_addr(SYSTEM), vir2phys(&v), sizeof(v))) != OK) {
minix_panic("lin_lin_copy for phys_get32 failed", r);
}
return v;
}
PRIVATE u32_t vm_cr3; /* temp arg to level0() func */
PRIVATE void set_cr3()
{
write_cr3(vm_cr3);
}
PUBLIC void vm_set_cr3(struct proc *newptproc)
{
int u = 0;
if(!intr_disabled()) { lock; u = 1; }
vm_cr3= newptproc->p_seg.p_cr3;
if(vm_cr3) {
level0(set_cr3);
ptproc = newptproc;
}
if(u) { unlock; }
}
char *cr0_str(u32_t e)
{
static char str[80];
strcpy(str, "");
#define FLAG(v) do { if(e & (v)) { strcat(str, #v " "); e &= ~v; } } while(0)
FLAG(I386_CR0_PE);
FLAG(I386_CR0_MP);
FLAG(I386_CR0_EM);
FLAG(I386_CR0_TS);
FLAG(I386_CR0_ET);
FLAG(I386_CR0_PG);
FLAG(I386_CR0_WP);
if(e) { strcat(str, " (++)"); }
return str;
}
char *cr4_str(u32_t e)
{
static char str[80];
strcpy(str, "");
FLAG(I386_CR4_VME);
FLAG(I386_CR4_PVI);
FLAG(I386_CR4_TSD);
FLAG(I386_CR4_DE);
FLAG(I386_CR4_PSE);
FLAG(I386_CR4_PAE);
FLAG(I386_CR4_MCE);
FLAG(I386_CR4_PGE);
if(e) { strcat(str, " (++)"); }
return str;
}
PRIVATE void vm_enable_paging(void)
{
u32_t cr0, cr4;
int pgeok;
psok = _cpufeature(_CPUF_I386_PSE);
pgeok = _cpufeature(_CPUF_I386_PGE);
cr0= read_cr0();
cr4= read_cr4();
/* First clear PG and PGE flag, as PGE must be enabled after PG. */
write_cr0(cr0 & ~I386_CR0_PG);
write_cr4(cr4 & ~(I386_CR4_PGE | I386_CR4_PSE));
cr0= read_cr0();
cr4= read_cr4();
/* Our first page table contains 4MB entries. */
if(psok)
cr4 |= I386_CR4_PSE;
write_cr4(cr4);
/* First enable paging, then enable global page flag. */
cr0 |= I386_CR0_PG;
write_cr0(cr0 );
cr0 |= I386_CR0_WP;
write_cr0(cr0);
/* May we enable these features? */
if(pgeok)
cr4 |= I386_CR4_PGE;
write_cr4(cr4);
}
PUBLIC vir_bytes alloc_remote_segment(u32_t *selector,
segframe_t *segments, int index, phys_bytes phys, vir_bytes size,
int priv)
{
phys_bytes offset = 0;
/* Check if the segment size can be recorded in bytes, that is, check
* if descriptor's limit field can delimited the allowed memory region
* precisely. This works up to 1MB. If the size is larger, 4K pages
* instead of bytes are used.
*/
if (size < BYTE_GRAN_MAX) {
init_dataseg(&segments->p_ldt[EXTRA_LDT_INDEX+index],
phys, size, priv);
*selector = ((EXTRA_LDT_INDEX+index)*0x08) | (1*0x04) | priv;
offset = 0;
} else {
init_dataseg(&segments->p_ldt[EXTRA_LDT_INDEX+index],
phys & ~0xFFFF, 0, priv);
*selector = ((EXTRA_LDT_INDEX+index)*0x08) | (1*0x04) | priv;
offset = phys & 0xFFFF;
}
return offset;
}
PUBLIC phys_bytes umap_remote(struct proc* rp, int seg,
vir_bytes vir_addr, vir_bytes bytes)
{
/* Calculate the physical memory address for a given virtual address. */
struct far_mem *fm;
#if 0
if(rp->p_misc_flags & MF_FULLVM) return 0;
#endif
if (bytes <= 0) return( (phys_bytes) 0);
if (seg < 0 || seg >= NR_REMOTE_SEGS) return( (phys_bytes) 0);
fm = &rp->p_priv->s_farmem[seg];
if (! fm->in_use) return( (phys_bytes) 0);
if (vir_addr + bytes > fm->mem_len) return( (phys_bytes) 0);
return(fm->mem_phys + (phys_bytes) vir_addr);
}
/*===========================================================================*
* umap_local *
*===========================================================================*/
PUBLIC phys_bytes umap_local(rp, seg, vir_addr, bytes)
register struct proc *rp; /* pointer to proc table entry for process */
int seg; /* T, D, or S segment */
vir_bytes vir_addr; /* virtual address in bytes within the seg */
vir_bytes bytes; /* # of bytes to be copied */
{
/* Calculate the physical memory address for a given virtual address. */
vir_clicks vc; /* the virtual address in clicks */
phys_bytes pa; /* intermediate variables as phys_bytes */
phys_bytes seg_base;
if(seg != T && seg != D && seg != S)
minix_panic("umap_local: wrong seg", seg);
if (bytes <= 0) return( (phys_bytes) 0);
if (vir_addr + bytes <= vir_addr) return 0; /* overflow */
vc = (vir_addr + bytes - 1) >> CLICK_SHIFT; /* last click of data */
if (seg != T)
seg = (vc < rp->p_memmap[D].mem_vir + rp->p_memmap[D].mem_len ? D : S);
if ((vir_addr>>CLICK_SHIFT) >= rp->p_memmap[seg].mem_vir +
rp->p_memmap[seg].mem_len) return( (phys_bytes) 0 );
if (vc >= rp->p_memmap[seg].mem_vir +
rp->p_memmap[seg].mem_len) return( (phys_bytes) 0 );
seg_base = (phys_bytes) rp->p_memmap[seg].mem_phys;
seg_base = seg_base << CLICK_SHIFT; /* segment origin in bytes */
pa = (phys_bytes) vir_addr;
pa -= rp->p_memmap[seg].mem_vir << CLICK_SHIFT;
return(seg_base + pa);
}
/*===========================================================================*
* umap_virtual *
*===========================================================================*/
PUBLIC phys_bytes umap_virtual(rp, seg, vir_addr, bytes)
register struct proc *rp; /* pointer to proc table entry for process */
int seg; /* T, D, or S segment */
vir_bytes vir_addr; /* virtual address in bytes within the seg */
vir_bytes bytes; /* # of bytes to be copied */
{
vir_bytes linear;
u32_t phys = 0;
if(seg == MEM_GRANT) {
phys = umap_grant(rp, vir_addr, bytes);
} else {
if(!(linear = umap_local(rp, seg, vir_addr, bytes))) {
kprintf("SYSTEM:umap_virtual: umap_local failed\n");
phys = 0;
} else {
if(vm_lookup(rp, linear, &phys, NULL) != OK) {
kprintf("SYSTEM:umap_virtual: vm_lookup of %s: seg 0x%lx: 0x%lx failed\n", rp->p_name, seg, vir_addr);
phys = 0;
}
if(phys == 0)
minix_panic("vm_lookup returned phys", phys);
}
}
if(phys == 0) {
kprintf("SYSTEM:umap_virtual: lookup failed\n");
return 0;
}
/* Now make sure addresses are contiguous in physical memory
* so that the umap makes sense.
*/
if(bytes > 0 && !vm_contiguous(rp, linear, bytes)) {
kprintf("umap_virtual: %s: %d at 0x%lx (vir 0x%lx) not contiguous\n",
rp->p_name, bytes, linear, vir_addr);
return 0;
}
/* phys must be larger than 0 (or the caller will think the call
* failed), and address must not cross a page boundary.
*/
vmassert(phys);
return phys;
}
/*===========================================================================*
* vm_lookup *
*===========================================================================*/
PUBLIC int vm_lookup(struct proc *proc, vir_bytes virtual, vir_bytes *physical, u32_t *ptent)
{
u32_t *root, *pt;
int pde, pte;
u32_t pde_v, pte_v;
NOREC_ENTER(vmlookup);
vmassert(proc);
vmassert(physical);
vmassert(!(proc->p_rts_flags & SLOT_FREE));
if(!HASPT(proc)) {
*physical = virtual;
NOREC_RETURN(vmlookup, OK);
}
/* Retrieve page directory entry. */
root = (u32_t *) proc->p_seg.p_cr3;
vmassert(!((u32_t) root % I386_PAGE_SIZE));
pde = I386_VM_PDE(virtual);
vmassert(pde >= 0 && pde < I386_VM_DIR_ENTRIES);
pde_v = phys_get32((u32_t) (root + pde));
if(!(pde_v & I386_VM_PRESENT)) {
NOREC_RETURN(vmlookup, EFAULT);
}
/* We don't expect to ever see this. */
if(pde_v & I386_VM_BIGPAGE) {
*physical = pde_v & I386_VM_ADDR_MASK_4MB;
if(ptent) *ptent = pde_v;
*physical += virtual & I386_VM_OFFSET_MASK_4MB;
} else {
/* Retrieve page table entry. */
pt = (u32_t *) I386_VM_PFA(pde_v);
vmassert(!((u32_t) pt % I386_PAGE_SIZE));
pte = I386_VM_PTE(virtual);
vmassert(pte >= 0 && pte < I386_VM_PT_ENTRIES);
pte_v = phys_get32((u32_t) (pt + pte));
if(!(pte_v & I386_VM_PRESENT)) {
NOREC_RETURN(vmlookup, EFAULT);
}
if(ptent) *ptent = pte_v;
/* Actual address now known; retrieve it and add page offset. */
*physical = I386_VM_PFA(pte_v);
*physical += virtual % I386_PAGE_SIZE;
}
NOREC_RETURN(vmlookup, OK);
}
/* From virtual address v in process p,
* lookup physical address and assign it to d.
* If p is NULL, assume it's already a physical address.
*/
#define LOOKUP(d, p, v, flagsp) { \
int r; \
if(!(p)) { (d) = (v); } \
else { \
if((r=vm_lookup((p), (v), &(d), flagsp)) != OK) { \
kprintf("vm_copy: lookup failed of 0x%lx in %d (%s)\n"\
"kernel stacktrace: ", (v), (p)->p_endpoint, \
(p)->p_name); \
util_stacktrace(); \
return r; \
} } }
/*===========================================================================*
* vm_contiguous *
*===========================================================================*/
PUBLIC int vm_contiguous(struct proc *targetproc, u32_t vir_buf, size_t bytes)
{
int first = 1, r, boundaries = 0;
u32_t prev_phys, po;
u32_t prev_vir;
vmassert(targetproc);
vmassert(bytes > 0);
if(!HASPT(targetproc))
return 1;
/* Start and end at page boundary to make logic simpler. */
po = vir_buf % I386_PAGE_SIZE;
if(po > 0) {
bytes += po;
vir_buf -= po;
}
po = (vir_buf + bytes) % I386_PAGE_SIZE;
if(po > 0)
bytes += I386_PAGE_SIZE - po;
/* Keep going as long as we cross a page boundary. */
while(bytes > 0) {
u32_t phys;
if((r=vm_lookup(targetproc, vir_buf, &phys, NULL)) != OK) {
kprintf("vm_contiguous: vm_lookup failed, %d\n", r);
kprintf("kernel stack: ");
util_stacktrace();
return 0;
}
if(!first) {
if(prev_phys+I386_PAGE_SIZE != phys) {
kprintf("vm_contiguous: no (0x%lx, 0x%lx)\n",
prev_phys, phys);
kprintf("kernel stack: ");
util_stacktrace();
return 0;
}
}
first = 0;
prev_phys = phys;
prev_vir = vir_buf;
vir_buf += I386_PAGE_SIZE;
bytes -= I386_PAGE_SIZE;
boundaries++;
}
return 1;
}
/*===========================================================================*
* vm_suspend *
*===========================================================================*/
PUBLIC int vm_suspend(struct proc *caller, struct proc *target,
vir_bytes linaddr, vir_bytes len, int wrflag, int type)
{
/* This range is not OK for this process. Set parameters
* of the request and notify VM about the pending request.
*/
vmassert(!RTS_ISSET(caller, VMREQUEST));
vmassert(!RTS_ISSET(target, VMREQUEST));
RTS_LOCK_SET(caller, VMREQUEST);
#if DEBUG_VMASSERT
caller->p_vmrequest.stacktrace[0] = '\0';
util_stacktrace_strcat(caller->p_vmrequest.stacktrace);
#endif
caller->p_vmrequest.writeflag = 1;
caller->p_vmrequest.start = linaddr;
caller->p_vmrequest.length = len;
caller->p_vmrequest.who = target->p_endpoint;
caller->p_vmrequest.type = type;
/* Connect caller on vmrequest wait queue. */
if(!(caller->p_vmrequest.nextrequestor = vmrequest))
mini_notify(proc_addr(SYSTEM), VM_PROC_NR);
vmrequest = caller;
}
/*===========================================================================*
* delivermsg *
*===========================================================================*/
int delivermsg(struct proc *rp)
{
phys_bytes addr;
int r;
NOREC_ENTER(deliver);
vmassert(rp->p_misc_flags & MF_DELIVERMSG);
vmassert(rp->p_delivermsg.m_source != NONE);
vmassert(rp->p_delivermsg_lin);
#if DEBUG_VMASSERT
if(rp->p_delivermsg_lin !=
umap_local(rp, D, rp->p_delivermsg_vir, sizeof(message))) {
printf("vir: 0x%lx lin was: 0x%lx umap now: 0x%lx\n",
rp->p_delivermsg_vir, rp->p_delivermsg_lin,
umap_local(rp, D, rp->p_delivermsg_vir, sizeof(message)));
minix_panic("that's wrong", NO_NUM);
}
#endif
vm_set_cr3(rp);
PHYS_COPY_CATCH(vir2phys(&rp->p_delivermsg),
rp->p_delivermsg_lin, sizeof(message), addr);
if(addr) {
vm_suspend(rp, rp, rp->p_delivermsg_lin, sizeof(message), 1,
VMSTYPE_DELIVERMSG);
r = VMSUSPEND;
} else {
#if DEBUG_VMASSERT
rp->p_delivermsg.m_source = NONE;
rp->p_delivermsg_lin = 0;
#endif
rp->p_misc_flags &= ~MF_DELIVERMSG;
r = OK;
}
NOREC_RETURN(deliver, r);
}
char *flagstr(u32_t e, int dir)
{
static char str[80];
strcpy(str, "");
FLAG(I386_VM_PRESENT);
FLAG(I386_VM_WRITE);
FLAG(I386_VM_USER);
FLAG(I386_VM_PWT);
FLAG(I386_VM_PCD);
FLAG(I386_VM_GLOBAL);
if(dir)
FLAG(I386_VM_BIGPAGE); /* Page directory entry only */
else
FLAG(I386_VM_DIRTY); /* Page table entry only */
return str;
}
void vm_pt_print(u32_t *pagetable, u32_t v)
{
int pte, l = 0;
int col = 0;
vmassert(!((u32_t) pagetable % I386_PAGE_SIZE));
for(pte = 0; pte < I386_VM_PT_ENTRIES; pte++) {
u32_t pte_v, pfa;
pte_v = phys_get32((u32_t) (pagetable + pte));
if(!(pte_v & I386_VM_PRESENT))
continue;
pfa = I386_VM_PFA(pte_v);
kprintf("%4d:%08lx:%08lx %2s ",
pte, v + I386_PAGE_SIZE*pte, pfa,
(pte_v & I386_VM_WRITE) ? "rw":"RO");
col++;
if(col == 3) { kprintf("\n"); col = 0; }
}
if(col > 0) kprintf("\n");
return;
}
void vm_print(u32_t *root)
{
int pde;
vmassert(!((u32_t) root % I386_PAGE_SIZE));
printf("page table 0x%lx:\n", root);
for(pde = 10; pde < I386_VM_DIR_ENTRIES; pde++) {
u32_t pde_v;
u32_t *pte_a;
pde_v = phys_get32((u32_t) (root + pde));
if(!(pde_v & I386_VM_PRESENT))
continue;
if(pde_v & I386_VM_BIGPAGE) {
kprintf("%4d: 0x%lx, flags %s\n",
pde, I386_VM_PFA(pde_v), flagstr(pde_v, 1));
} else {
pte_a = (u32_t *) I386_VM_PFA(pde_v);
kprintf("%4d: pt %08lx %s\n",
pde, pte_a, flagstr(pde_v, 1));
vm_pt_print(pte_a, pde * I386_VM_PT_ENTRIES * I386_PAGE_SIZE);
kprintf("\n");
}
}
return;
}
u32_t thecr3;
u32_t read_cr3(void)
{
level0(getcr3val);
return thecr3;
}
/*===========================================================================*
* lin_memset *
*===========================================================================*/
int vm_phys_memset(phys_bytes ph, u8_t c, phys_bytes bytes)
{
char *v;
u32_t p;
NOREC_ENTER(physmemset);
p = c | (c << 8) | (c << 16) | (c << 24);
if(!vm_running) {
phys_memset(ph, p, bytes);
NOREC_RETURN(physmemset, OK);
}
vmassert(nfreepdes >= 3);
/* With VM, we have to map in the physical memory.
* We can do this 4MB at a time.
*/
while(bytes > 0) {
int pde, t;
vir_bytes chunk = bytes;
phys_bytes ptr;
inusepde = NOPDE;
CREATEPDE(((struct proc *) NULL), ptr, ph, chunk, bytes, pde, t);
/* We can memset as many bytes as we have remaining,
* or as many as remain in the 4MB chunk we mapped in.
*/
phys_memset(ptr, p, chunk);
DONEPDE(pde);
bytes -= chunk;
ph += chunk;
}
NOREC_RETURN(physmemset, OK);
}
/*===========================================================================*
* virtual_copy_f *
*===========================================================================*/
PUBLIC int virtual_copy_f(src_addr, dst_addr, bytes, vmcheck)
struct vir_addr *src_addr; /* source virtual address */
struct vir_addr *dst_addr; /* destination virtual address */
vir_bytes bytes; /* # of bytes to copy */
int vmcheck; /* if nonzero, can return VMSUSPEND */
{
/* Copy bytes from virtual address src_addr to virtual address dst_addr.
* Virtual addresses can be in ABS, LOCAL_SEG, REMOTE_SEG, or BIOS_SEG.
*/
struct vir_addr *vir_addr[2]; /* virtual source and destination address */
phys_bytes phys_addr[2]; /* absolute source and destination */
int seg_index;
int i, r;
struct proc *procs[2];
NOREC_ENTER(virtualcopy);
/* Check copy count. */
if (bytes <= 0) return(EDOM);
/* Do some more checks and map virtual addresses to physical addresses. */
vir_addr[_SRC_] = src_addr;
vir_addr[_DST_] = dst_addr;
for (i=_SRC_; i<=_DST_; i++) {
int proc_nr, type;
struct proc *p;
type = vir_addr[i]->segment & SEGMENT_TYPE;
if((type != PHYS_SEG && type != BIOS_SEG) &&
isokendpt(vir_addr[i]->proc_nr_e, &proc_nr))
p = proc_addr(proc_nr);
else
p = NULL;
procs[i] = p;
/* Get physical address. */
switch(type) {
case LOCAL_SEG:
case LOCAL_VM_SEG:
if(!p) {
NOREC_RETURN(virtualcopy, EDEADSRCDST);
}
seg_index = vir_addr[i]->segment & SEGMENT_INDEX;
if(type == LOCAL_SEG)
phys_addr[i] = umap_local(p, seg_index, vir_addr[i]->offset,
bytes);
else
phys_addr[i] = umap_virtual(p, seg_index, vir_addr[i]->offset,
bytes);
if(phys_addr[i] == 0) {
kprintf("virtual_copy: map 0x%x failed for %s seg %d, "
"offset %lx, len %d, i %d\n",
type, p->p_name, seg_index, vir_addr[i]->offset,
bytes, i);
}
break;
case REMOTE_SEG:
if(!p) {
NOREC_RETURN(virtualcopy, EDEADSRCDST);
}
seg_index = vir_addr[i]->segment & SEGMENT_INDEX;
phys_addr[i] = umap_remote(p, seg_index, vir_addr[i]->offset, bytes);
break;
#if _MINIX_CHIP == _CHIP_INTEL
case BIOS_SEG:
phys_addr[i] = umap_bios(vir_addr[i]->offset, bytes );
break;
#endif
case PHYS_SEG:
phys_addr[i] = vir_addr[i]->offset;
break;
default:
kprintf("virtual_copy: strange type 0x%x\n", type);
NOREC_RETURN(virtualcopy, EINVAL);
}
/* Check if mapping succeeded. */
if (phys_addr[i] <= 0 && vir_addr[i]->segment != PHYS_SEG) {
kprintf("virtual_copy EFAULT\n");
NOREC_RETURN(virtualcopy, EFAULT);
}
}
if(vm_running) {
int r;
struct proc *caller;
caller = proc_addr(who_p);
if(RTS_ISSET(caller, VMREQUEST)) {
struct proc *target;
int pn;
vmassert(caller->p_vmrequest.vmresult != VMSUSPEND);
RTS_LOCK_UNSET(caller, VMREQUEST);
if(caller->p_vmrequest.vmresult != OK) {
printf("virtual_copy: returning VM error %d\n",
caller->p_vmrequest.vmresult);
NOREC_RETURN(virtualcopy, caller->p_vmrequest.vmresult);
}
}
if((r=lin_lin_copy(procs[_SRC_], phys_addr[_SRC_],
procs[_DST_], phys_addr[_DST_], bytes)) != OK) {
struct proc *target;
int wr;
phys_bytes lin;
if(r != EFAULT_SRC && r != EFAULT_DST)
minix_panic("lin_lin_copy failed", r);
if(!vmcheck) {
NOREC_RETURN(virtualcopy, r);
}
vmassert(procs[_SRC_] && procs[_DST_]);
if(r == EFAULT_SRC) {
lin = phys_addr[_SRC_];
target = procs[_SRC_];
wr = 0;
} else if(r == EFAULT_DST) {
lin = phys_addr[_DST_];
target = procs[_DST_];
wr = 1;
} else {
minix_panic("r strange", r);
}
#if 0
printf("virtual_copy: suspending caller %d / %s, target %d / %s\n",
caller->p_endpoint, caller->p_name,
target->p_endpoint, target->p_name);
#endif
vmassert(proc_ptr->p_endpoint == SYSTEM);
vm_suspend(caller, target, lin, bytes, wr, VMSTYPE_KERNELCALL);
NOREC_RETURN(virtualcopy, VMSUSPEND);
}
NOREC_RETURN(virtualcopy, OK);
}
vmassert(!vm_running);
/* can't copy to/from process with PT without VM */
#define NOPT(p) (!(p) || !HASPT(p))
if(!NOPT(procs[_SRC_])) {
kprintf("ignoring page table src: %s / %d at 0x%lx\n",
procs[_SRC_]->p_name, procs[_SRC_]->p_endpoint, procs[_SRC_]->p_seg.p_cr3);
}
if(!NOPT(procs[_DST_])) {
kprintf("ignoring page table dst: %s / %d at 0x%lx\n",
procs[_DST_]->p_name, procs[_DST_]->p_endpoint,
procs[_DST_]->p_seg.p_cr3);
}
/* Now copy bytes between physical addresseses. */
if(phys_copy(phys_addr[_SRC_], phys_addr[_DST_], (phys_bytes) bytes))
NOREC_RETURN(virtualcopy, EFAULT);
NOREC_RETURN(virtualcopy, OK);
}
/*===========================================================================*
* data_copy *
*===========================================================================*/
PUBLIC int data_copy(
endpoint_t from_proc, vir_bytes from_addr,
endpoint_t to_proc, vir_bytes to_addr,
size_t bytes)
{
struct vir_addr src, dst;
src.segment = dst.segment = D;
src.offset = from_addr;
dst.offset = to_addr;
src.proc_nr_e = from_proc;
dst.proc_nr_e = to_proc;
return virtual_copy(&src, &dst, bytes);
}
/*===========================================================================*
* data_copy_vmcheck *
*===========================================================================*/
PUBLIC int data_copy_vmcheck(
endpoint_t from_proc, vir_bytes from_addr,
endpoint_t to_proc, vir_bytes to_addr,
size_t bytes)
{
struct vir_addr src, dst;
src.segment = dst.segment = D;
src.offset = from_addr;
dst.offset = to_addr;
src.proc_nr_e = from_proc;
dst.proc_nr_e = to_proc;
return virtual_copy_vmcheck(&src, &dst, bytes);
}
/*===========================================================================*
* arch_pre_exec *
*===========================================================================*/
PUBLIC int arch_pre_exec(struct proc *pr, u32_t ip, u32_t sp)
{
/* wipe extra LDT entries, set program counter, and stack pointer. */
memset(pr->p_seg.p_ldt + EXTRA_LDT_INDEX, 0,
sizeof(pr->p_seg.p_ldt[0]) * (LDT_SIZE - EXTRA_LDT_INDEX));
pr->p_reg.pc = ip;
pr->p_reg.sp = sp;
}
/*===========================================================================*
* arch_umap *
*===========================================================================*/
PUBLIC int arch_umap(struct proc *pr, vir_bytes offset, vir_bytes count,
int seg, phys_bytes *addr)
{
switch(seg) {
case BIOS_SEG:
*addr = umap_bios(offset, count);
return OK;
}
/* This must be EINVAL; the umap fallback function in
* lib/syslib/alloc_util.c depends on it to detect an
* older kernel (as opposed to mapping error).
*/
return EINVAL;
}
/* VM reports page directory slot we're allowed to use freely. */
void i386_freepde(int pde)
{
if(nfreepdes >= WANT_FREEPDES)
return;
freepdes[nfreepdes++] = pde;
}
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