/* Unregister an interrupt handler. */
PUBLIC void rm_irq_handler( irq_hook_t* hook ) {
int irq = hook->irq;
int id = hook->id;
irq_hook_t **line;
if( irq < 0 || irq >= NR_IRQ_VECTORS )
minix_panic("invalid call to rm_irq_handler", irq);
/* disable the irq. */
irq_actids[hook->irq] |= hook->id;
hw_intr_mask(hook->irq);
/* remove the hook. */
line = &irq_handlers[irq];
while( (*line) != NULL ) {
if((*line)->id == id) {
(*line) = (*line)->next;
if(!irq_handlers[irq])
irq_use &= ~(1 << irq);
if (irq_actids[irq] & id)
irq_actids[irq] &= ~id;
return;
}
line = &(*line)->next;
}
/* When the handler is not found, normally return here. */
}
/*===========================================================================*
* clock_task *
*===========================================================================*/
PUBLIC void clock_task()
{
/* Main program of clock task. If the call is not HARD_INT it is an error.
*/
message m; /* message buffer for both input and output */
int result; /* result returned by the handler */
init_clock(); /* initialize clock task */
/* Main loop of the clock task. Get work, process it. Never reply. */
while(TRUE) {
/* Go get a message. */
result = receive(ANY, &m);
if(result != OK)
minix_panic("receive() failed", result);
/* Handle the request. Only clock ticks are expected. */
switch (m.m_type) {
case HARD_INT:
do_clocktick(&m); /* handle clock tick */
break;
default: /* illegal request type */
kprintf("CLOCK: illegal request %d from %d.\n",
m.m_type, m.m_source);
}
}
}
void pagefault(struct proc *pr, int trap_errno)
{
int s;
vir_bytes ph;
u32_t pte;
if(pagefault_count != 1)
minix_panic("recursive pagefault", pagefault_count);
/* Don't schedule this process until pagefault is handled. */
if(RTS_ISSET(pr, PAGEFAULT))
minix_panic("PAGEFAULT set", pr->p_endpoint);
RTS_LOCK_SET(pr, PAGEFAULT);
if(pr->p_endpoint <= INIT_PROC_NR) {
/* Page fault we can't / don't want to
* handle.
*/
kprintf("pagefault for process %d ('%s'), pc = 0x%x\n",
pr->p_endpoint, pr->p_name, pr->p_reg.pc);
proc_stacktrace(pr);
minix_panic("page fault in system process", pr->p_endpoint);
return;
}
/* Save pagefault details, suspend process,
* add process to pagefault chain,
* and tell VM there is a pagefault to be
* handled.
*/
pr->p_pagefault.pf_virtual = pagefault_cr2;
pr->p_pagefault.pf_flags = trap_errno;
pr->p_nextpagefault = pagefaults;
pagefaults = pr;
lock_notify(HARDWARE, VM_PROC_NR);
pagefault_count = 0;
#if 0
kprintf("pagefault for process %d ('%s'), pc = 0x%x\n",
pr->p_endpoint, pr->p_name, pr->p_reg.pc);
proc_stacktrace(pr);
#endif
return;
}
/*===========================================================================*
* panic *
*===========================================================================*/
PUBLIC void panic(char *what, char *mess,int nr)
{
/* This function is for when a library call wants to panic.
* The library call calls printf() and tries to exit a process,
* which isn't applicable in the kernel.
*/
minix_panic(mess, nr);
}
PUBLIC void vm_init(struct proc *newptproc)
{
if(vm_running)
minix_panic("vm_init: vm_running", NO_NUM);
vm_set_cr3(newptproc);
level0(vm_enable_paging);
vm_running = 1;
}
/* Register an interrupt handler. */
PUBLIC void put_irq_handler( irq_hook_t* hook, int irq, irq_handler_t handler)
{
int id;
irq_hook_t **line;
unsigned long bitmap;
if( irq < 0 || irq >= NR_IRQ_VECTORS )
minix_panic("invalid call to put_irq_handler", irq);
line = &irq_handlers[irq];
bitmap = 0;
while ( *line != NULL ) {
if(hook == *line) return; /* extra initialization */
bitmap |= (*line)->id; /* mark ids in use */
line = &(*line)->next;
}
/* find the lowest id not in use */
for (id = 1; id != 0; id <<= 1)
if (!(bitmap & id)) break;
if(id == 0)
minix_panic("Too many handlers for irq", irq);
hook->next = NULL;
hook->handler = handler;
hook->irq = irq;
hook->id = id;
*line = hook;
irq_use |= 1 << irq; /* this does not work for irq >= 32 */
/* And as last enable the irq at the hardware.
*
* Internal this activates the line or source of the given interrupt.
*/
if((irq_actids[hook->irq] &= ~hook->id) == 0) {
hw_intr_unmask(hook->irq);
}
}
PRIVATE u32_t phys_get32(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;
}
/*===========================================================================*
* sys_task *
*===========================================================================*/
PUBLIC void sys_task()
{
/* Main entry point of sys_task. Get the message and dispatch on type. */
static message m;
register int result;
register struct proc *caller_ptr;
int s;
int call_nr;
int n = 0;
/* Initialize the system task. */
initialize();
while (TRUE) {
struct proc *restarting;
restarting = vmrestart_check(&m);
if(!restarting) {
int r;
/* Get work. Block and wait until a request message arrives. */
if((r=receive(ANY, &m)) != OK)
minix_panic("receive() failed", r);
}
sys_call_code = (unsigned) m.m_type;
call_nr = sys_call_code - KERNEL_CALL;
who_e = m.m_source;
okendpt(who_e, &who_p);
caller_ptr = proc_addr(who_p);
/* See if the caller made a valid request and try to handle it. */
if (call_nr < 0 || call_nr >= NR_SYS_CALLS) { /* check call number */
kprintf("SYSTEM: illegal request %d from %d.\n",
call_nr,m.m_source);
result = EBADREQUEST; /* illegal message type */
}
else if (!GET_BIT(priv(caller_ptr)->s_k_call_mask, call_nr)) {
result = ECALLDENIED; /* illegal message type */
}
else {
result = (*call_vec[call_nr])(&m); /* handle the system call */
}
if(result == VMSUSPEND) {
/* Special case: message has to be saved for handling
* until VM tells us it's allowed. VM has been notified
* and we must wait for its reply to restart the call.
*/
vmassert(RTS_ISSET(caller_ptr, VMREQUEST));
vmassert(caller_ptr->p_vmrequest.type == VMSTYPE_KERNELCALL);
memcpy(&caller_ptr->p_vmrequest.saved.reqmsg, &m, sizeof(m));
} else if (result != EDONTREPLY) {
/* Send a reply, unless inhibited by a handler function.
* Use the kernel function lock_send() to prevent a system
* call trap.
*/
if(restarting) {
vmassert(!RTS_ISSET(restarting, VMREQUEST));
#if 0
vmassert(!RTS_ISSET(restarting, VMREQTARGET));
#endif
}
m.m_type = result; /* report status of call */
if(WILLRECEIVE(caller_ptr, SYSTEM)) {
if (OK != (s=lock_send(m.m_source, &m))) {
kprintf("SYSTEM, reply to %d failed: %d\n",
m.m_source, s);
}
} else {
kprintf("SYSTEM: not replying to %d; not ready\n",
caller_ptr->p_endpoint);
}
}
}
}
/*===========================================================================*
* lin_lin_copy *
*===========================================================================*/
PRIVATE int lin_lin_copy(struct proc *srcproc, vir_bytes srclinaddr,
struct proc *dstproc, vir_bytes dstlinaddr, vir_bytes bytes)
{
u32_t addr;
int procslot;
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;
}
NOREC_RETURN(linlincopy, OK);
}
PUBLIC void vm_init(void)
{
int o;
phys_bytes p, pt_size;
phys_bytes vm_dir_base, vm_pt_base, phys_mem;
u32_t entry;
unsigned pages;
struct proc* rp;
struct proc *sys = proc_addr(SYSTEM);
static int init_done = 0;
if (!vm_size)
minix_panic("i386_vm_init: no space for page tables", NO_NUM);
if(init_done)
return;
/* Align page directory */
o= (vm_base % I386_PAGE_SIZE);
if (o != 0)
o= I386_PAGE_SIZE-o;
vm_dir_base= vm_base+o;
/* Page tables start after the page directory */
vm_pt_base= vm_dir_base+I386_PAGE_SIZE;
pt_size= (vm_base+vm_size)-vm_pt_base;
pt_size -= (pt_size % I386_PAGE_SIZE);
/* Compute the number of pages based on vm_mem_high */
pages= (vm_mem_high-1)/I386_PAGE_SIZE + 1;
if (pages * I386_VM_PT_ENT_SIZE > pt_size)
minix_panic("i386_vm_init: page table too small", NO_NUM);
for (p= 0; p*I386_VM_PT_ENT_SIZE < pt_size; p++)
{
phys_mem= p*I386_PAGE_SIZE;
entry= phys_mem | I386_VM_USER | I386_VM_WRITE |
I386_VM_PRESENT;
if (phys_mem >= vm_mem_high)
entry= 0;
#if VM_KERN_NOPAGEZERO
if (phys_mem == (sys->p_memmap[T].mem_phys << CLICK_SHIFT) ||
phys_mem == (sys->p_memmap[D].mem_phys << CLICK_SHIFT)) {
entry = 0;
}
#endif
phys_put32(vm_pt_base + p*I386_VM_PT_ENT_SIZE, entry);
}
for (p= 0; p < I386_VM_DIR_ENTRIES; p++)
{
phys_mem= vm_pt_base + p*I386_PAGE_SIZE;
entry= phys_mem | I386_VM_USER | I386_VM_WRITE |
I386_VM_PRESENT;
if (phys_mem >= vm_pt_base + pt_size)
entry= 0;
phys_put32(vm_dir_base + p*I386_VM_PT_ENT_SIZE, entry);
}
/* Set this cr3 in all currently running processes for
* future context switches.
*/
for (rp=BEG_PROC_ADDR; rp<END_PROC_ADDR; rp++) {
u32_t mycr3;
if(isemptyp(rp)) continue;
rp->p_seg.p_cr3 = vm_dir_base;
}
kernel_cr3 = vm_dir_base;
/* Set this cr3 now (not active until paging enabled). */
vm_set_cr3(vm_dir_base);
/* Actually enable paging (activating cr3 load above). */
level0(vm_enable_paging);
/* Don't do this init in the future. */
init_done = 1;
vm_running = 1;
}