minix/servers/pm/main.c

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/* This file contains the main program of the process manager and some related
* procedures. When MINIX starts up, the kernel runs for a little while,
* initializing itself and its tasks, and then it runs PM and FS. Both PM
* and FS initialize themselves as far as they can. PM asks the kernel for
* all free memory and starts serving requests.
*
* The entry points into this file are:
* main: starts PM running
* setreply: set the reply to be sent to process making an PM system call
*/
#include "pm.h"
#include <minix/utils.h>
#include <minix/keymap.h>
#include <minix/callnr.h>
#include <minix/com.h>
#include <signal.h>
#include <stdlib.h>
#include <fcntl.h>
#include <sys/ioc_memory.h>
#include <string.h>
#include "mproc.h"
#include "param.h"
#include "../../kernel/const.h"
#include "../../kernel/type.h"
FORWARD _PROTOTYPE( void get_work, (void) );
FORWARD _PROTOTYPE( void pm_init, (void) );
FORWARD _PROTOTYPE( void get_mem_chunks, (struct memory *mem_chunks) );
FORWARD _PROTOTYPE( void patch_mem_chunks, (struct memory *mem_chunks,
struct mem_map *map_ptr) );
#define click_to_round_k(n) \
((unsigned) ((((unsigned long) (n) << CLICK_SHIFT) + 512) / 1024))
/*===========================================================================*
* main *
*===========================================================================*/
PUBLIC void main()
{
/* Main routine of the process manager. */
int result, s, proc_nr;
struct mproc *rmp;
pm_init(); /* initialize process manager tables */
/* This is PM's main loop- get work and do it, forever and forever. */
while (TRUE) {
get_work(); /* wait for an PM system call */
/* Check for system notifications first. Special cases. */
if (call_nr == HARD_STOP) { /* MINIX is shutting down */
check_sig(-1, SIGKILL); /* kill all processes */
sys_exit(0);
/* never reached */
} else if (call_nr == KSIG_PENDING) { /* signals pending */
(void) ksig_pending();
result = SUSPEND; /* don't reply */
}
/* Else, if the system call number is valid, perform the call. */
else if ((unsigned) call_nr >= NCALLS) {
result = ENOSYS;
} else {
result = (*call_vec[call_nr])();
}
/* Send the results back to the user to indicate completion. */
if (result != SUSPEND) setreply(who, result);
swap_in(); /* maybe a process can be swapped in? */
/* Send out all pending reply messages, including the answer to
* the call just made above. The processes must not be swapped out.
*/
for (proc_nr=0, rmp=mproc; proc_nr < NR_PROCS; proc_nr++, rmp++) {
if ((rmp->mp_flags & (REPLY | ONSWAP)) == REPLY) {
if ((s=send(proc_nr, &rmp->mp_reply)) != OK) {
panic(__FILE__,"PM can't reply to", proc_nr);
}
rmp->mp_flags &= ~REPLY;
}
}
}
}
/*===========================================================================*
* get_work *
*===========================================================================*/
PRIVATE void get_work()
{
/* Wait for the next message and extract useful information from it. */
if (receive(ANY, &m_in) != OK) panic(__FILE__,"PM receive error", NO_NUM);
who = m_in.m_source; /* who sent the message */
call_nr = m_in.m_type; /* system call number */
/* Process slot of caller. Misuse PM's own process slot if the kernel is
* calling. The can happen in case of pending kernel signals.
*/
mp = &mproc[who < 0 ? PM_PROC_NR : who];
}
/*===========================================================================*
* setreply *
*===========================================================================*/
PUBLIC void setreply(proc_nr, result)
int proc_nr; /* process to reply to */
int result; /* result of call (usually OK or error #) */
{
/* Fill in a reply message to be sent later to a user process. System calls
* may occasionally fill in other fields, this is only for the main return
* value, and for setting the "must send reply" flag.
*/
register struct mproc *rmp = &mproc[proc_nr];
rmp->mp_reply.reply_res = result;
rmp->mp_flags |= REPLY; /* reply pending */
if (rmp->mp_flags & ONSWAP)
swap_inqueue(rmp); /* must swap this process back in */
}
/*===========================================================================*
* pm_init *
*===========================================================================*/
PRIVATE void pm_init()
{
/* Initialize the process manager. */
int key, i, s;
static struct system_image image[IMAGE_SIZE];
register struct system_image *ip;
static char core_sigs[] = { SIGQUIT, SIGILL, SIGTRAP, SIGABRT,
SIGEMT, SIGFPE, SIGUSR1, SIGSEGV, SIGUSR2 };
static char ign_sigs[] = { SIGCHLD };
register int proc_nr;
register struct mproc *rmp;
register char *sig_ptr;
phys_clicks ram_clicks, total_clicks, minix_clicks, free_clicks;
message mess;
struct mem_map mem_map[NR_LOCAL_SEGS];
struct memory mem_chunks[NR_MEMS];
/* Build the set of signals which cause core dumps, and the set of signals
* that are by default ignored.
*/
sigemptyset(&core_sset);
for (sig_ptr = core_sigs; sig_ptr < core_sigs+sizeof(core_sigs); sig_ptr++)
sigaddset(&core_sset, *sig_ptr);
sigemptyset(&ign_sset);
for (sig_ptr = ign_sigs; sig_ptr < ign_sigs+sizeof(ign_sigs); sig_ptr++)
sigaddset(&ign_sset, *sig_ptr);
/* Obtain a copy of the boot monitor parameters and the kernel info struct.
* Parse the list of free memory chunks. This list is what the boot monitor
* reported, but it must be corrected for the kernel and system processes.
*/
if ((s=sys_getmonparams(monitor_params, sizeof(monitor_params))) != OK)
panic(__FILE__,"get monitor params failed",s);
if ((s=sys_getkinfo(&kinfo)) != OK)
panic(__FILE__,"get kernel info failed",s);
get_mem_chunks(mem_chunks);
/* Get the memory map of the kernel to see how much memory it uses. */
if ((s=get_mem_map(SYSTASK, mem_map)) != OK)
panic(__FILE__,"PM couldn't get memory map of SYSTASK",s);
minix_clicks = (mem_map[S].mem_phys+mem_map[S].mem_len)-mem_map[T].mem_phys;
patch_mem_chunks(mem_chunks, mem_map);
/* Initialize PM's process table. Request a copy of the system image table
* that is defined at the kernel level to see which slots to fill in.
*/
if (OK != (s=sys_getimage(&image)))
panic(__FILE__,"PM: warning, couldn't get image table: %d\n", s);
procs_in_use = 0; /* start populating table */
for (ip = &image[0]; ip < &image[IMAGE_SIZE]; ip++) {
if (ip->proc_nr >= 0) { /* task have negative nrs */
procs_in_use += 1; /* found user process */
/* Set process details found in the image table. */
rmp = &mproc[ip->proc_nr];
rmp->mp_flags |= IN_USE | DONT_SWAP;
rmp->mp_pid = (ip->proc_nr == INIT_PROC_NR) ?
INIT_PID : get_free_pid();
strncpy(rmp->mp_name, ip->proc_name, PROC_NAME_LEN);
/* Change local signal handling behaviour. */
sigfillset(&rmp->mp_ignore);
sigfillset(&rmp->mp_sigmask);
sigemptyset(&rmp->mp_catch);
/* Get memory map for this process from the kernel. */
if ((s=get_mem_map(ip->proc_nr, rmp->mp_seg)) != OK)
panic(__FILE__,"couldn't get process entry",s);
if (rmp->mp_seg[T].mem_len != 0) rmp->mp_flags |= SEPARATE;
minix_clicks += rmp->mp_seg[S].mem_phys +
rmp->mp_seg[S].mem_len - rmp->mp_seg[T].mem_phys;
patch_mem_chunks(mem_chunks, rmp->mp_seg);
/* Tell FS about this system process. */
mess.PR_PROC_NR = ip->proc_nr;
mess.PR_PID = rmp->mp_pid;
if (OK != (s=send(FS_PROC_NR, &mess)))
panic(__FILE__,"PM can't sync up with FS", s);
}
}
/* Tell FS that no more system processes follow and synchronize. */
mess.PR_PROC_NR = NONE;
if (sendrec(FS_PROC_NR, &mess) != OK || mess.m_type != OK)
panic(__FILE__,"PM can't sync up with FS", NO_NUM);
/* INIT process is somewhat special. */
sigemptyset(&mproc[INIT_PROC_NR].mp_ignore);
sigemptyset(&mproc[INIT_PROC_NR].mp_sigmask);
sigemptyset(&mproc[INIT_PROC_NR].mp_catch);
/* Possibly we must correct the memory chunks for the boot device. */
if (kinfo.bootdev_size > 0) {
mem_map[T].mem_phys = kinfo.bootdev_base >> CLICK_SHIFT;
mem_map[T].mem_len = 0;
mem_map[D].mem_len = (kinfo.bootdev_size+CLICK_SIZE-1) >> CLICK_SHIFT;
patch_mem_chunks(mem_chunks, mem_map);
}
/* Initialize tables to all physical memory and print memory information. */
mem_init(mem_chunks, &free_clicks);
total_clicks = minix_clicks + free_clicks;
printf("Memory size=%uK ", click_to_round_k(total_clicks));
printf("System services=%uK ", click_to_round_k(minix_clicks));
printf("Available=%uK\n\n", click_to_round_k(free_clicks));
}
/* In real mode only 1M can be addressed, and in 16-bit protected we can go
* no further than we can count in clicks. (The 286 is further limited by
* its 24 bit address bus, but we can assume in that case that no more than
* 16M memory is reported by the BIOS.)
*/
#define MAX_REAL 0x00100000L
#define MAX_16BIT (0xFFF0L << CLICK_SHIFT)
/*=========================================================================*
* get_mem_chunks *
*=========================================================================*/
PRIVATE void get_mem_chunks(mem_chunks)
struct memory *mem_chunks; /* store mem chunks here */
{
/* Initialize the free memory list from the 'memory' boot variable. Translate
* the byte offsets and sizes in this list to clicks, properly truncated. Also
* make sure that we don't exceed the maximum address space of the 286 or the
* 8086, i.e. when running in 16-bit protected mode or real mode.
*/
long base, size, limit;
char *s, *end; /* use to parse boot variable */
int i, done = 0;
struct memory *memp;
#if _WORD_SIZE == 2
unsigned long max_address;
struct machine machine;
if (OK != (i=sys_getmachine(&machine)))
panic(__FILE__, "sys_getmachine failed", i);
#endif
/* Initialize everything to zero. */
for (i = 0; i < NR_MEMS; i++) {
memp = &mem_chunks[i]; /* next mem chunk is stored here */
memp->base = memp->size = 0;
}
/* The available memory is determined by MINIX' boot loader as a list of
* (base:size)-pairs in boothead.s. The 'memory' boot variable is set in
* in boot.s. The format is "b0:s0,b1:s1,b2:s2", where b0:s0 is low mem,
* b1:s1 is mem between 1M and 16M, b2:s2 is mem above 16M. Pairs b1:s1
* and b2:s2 are combined if the memory is adjacent.
*/
s = find_param("memory"); /* get memory boot variable */
for (i = 0; i < NR_MEMS && !done; i++) {
memp = &mem_chunks[i]; /* next mem chunk is stored here */
base = size = 0; /* initialize next base:size pair */
if (*s != 0) { /* get fresh data, unless at end */
/* Read fresh base and expect colon as next char. */
base = strtoul(s, &end, 0x10); /* get number */
if (end != s && *end == ':') s = ++end; /* skip ':' */
else *s=0; /* terminate, should not happen */
/* Read fresh size and expect comma or assume end. */
size = strtoul(s, &end, 0x10); /* get number */
if (end != s && *end == ',') s = ++end; /* skip ',' */
else done = 1;
}
limit = base + size;
#if _WORD_SIZE == 2
max_address = machine.protected ? MAX_16BIT : MAX_REAL;
if (limit > max_address) limit = max_address;
#endif
base = (base + CLICK_SIZE-1) & ~(long)(CLICK_SIZE-1);
limit &= ~(long)(CLICK_SIZE-1);
if (limit <= base) continue;
memp->base = base >> CLICK_SHIFT;
memp->size = (limit - base) >> CLICK_SHIFT;
}
}
/*=========================================================================*
* patch_mem_chunks *
*=========================================================================*/
PRIVATE void patch_mem_chunks(mem_chunks, map_ptr)
struct memory *mem_chunks; /* store mem chunks here */
struct mem_map *map_ptr; /* memory to remove */
{
/* Remove server memory from the free memory list. The boot monitor
* promises to put processes at the start of memory chunks. The
* tasks all use same base address, so only the first task changes
* the memory lists. The servers and init have their own memory
* spaces and their memory will be removed from the list.
*/
struct memory *memp;
for (memp = mem_chunks; memp < &mem_chunks[NR_MEMS]; memp++) {
if (memp->base == map_ptr[T].mem_phys) {
memp->base += map_ptr[T].mem_len + map_ptr[D].mem_len;
memp->size -= map_ptr[T].mem_len + map_ptr[D].mem_len;
}
}
}