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minix/drivers/memory/memory.c
Ben Gras 3beb81a5d0 memory driver: munmap() imgrd after first close. 
(that munmap() range not supported yet by vm.)
2011-02-10 15:39:56 +00:00

510 lines
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/* This file contains the device dependent part of the drivers for the
* following special files:
* /dev/ram - RAM disk
* /dev/mem - absolute memory
* /dev/kmem - kernel virtual memory
* /dev/null - null device (data sink)
* /dev/boot - boot device loaded from boot image
* /dev/zero - null byte stream generator
* /dev/imgrd - boot image RAM disk
*
* Changes:
* Apr 29, 2005 added null byte generator (Jorrit N. Herder)
* Apr 09, 2005 added support for boot device (Jorrit N. Herder)
* Jul 26, 2004 moved RAM driver to user-space (Jorrit N. Herder)
* Apr 20, 1992 device dependent/independent split (Kees J. Bot)
*/
#include <minix/drivers.h>
#include <minix/driver.h>
#include <sys/ioc_memory.h>
#include <minix/ds.h>
#include <minix/vm.h>
#include <machine/param.h>
#include <sys/mman.h>
#include "kernel/const.h"
#include "kernel/config.h"
#include "kernel/type.h"
#include <machine/vm.h>
#include "local.h"
/* ramdisks (/dev/ram*) */
#define RAMDISKS 6
#define RAM_DEV_LAST (RAM_DEV_FIRST+RAMDISKS-1)
#define NR_DEVS (7+RAMDISKS) /* number of minor devices */
PRIVATE struct device m_geom[NR_DEVS]; /* base and size of each device */
PRIVATE vir_bytes m_vaddrs[NR_DEVS];
PRIVATE int m_device; /* current device */
PRIVATE struct kinfo kinfo; /* kernel information */
extern int errno; /* error number for PM calls */
PRIVATE int openct[NR_DEVS];
FORWARD _PROTOTYPE( char *m_name, (void) );
FORWARD _PROTOTYPE( struct device *m_prepare, (int device) );
FORWARD _PROTOTYPE( int m_transfer, (int proc_nr, int opcode,
u64_t position, iovec_t *iov, unsigned nr_req) );
FORWARD _PROTOTYPE( int m_do_open, (struct driver *dp, message *m_ptr) );
FORWARD _PROTOTYPE( int m_do_close, (struct driver *dp, message *m_ptr) );
FORWARD _PROTOTYPE( int m_ioctl, (struct driver *dp, message *m_ptr) );
FORWARD _PROTOTYPE( void m_geometry, (struct partition *entry) );
/* Entry points to this driver. */
PRIVATE struct driver m_dtab = {
m_name, /* current device's name */
m_do_open, /* open or mount */
m_do_close, /* nothing on a close */
m_ioctl, /* specify ram disk geometry */
m_prepare, /* prepare for I/O on a given minor device */
m_transfer, /* do the I/O */
nop_cleanup, /* no need to clean up */
m_geometry, /* memory device "geometry" */
nop_alarm,
nop_cancel,
nop_select,
NULL,
NULL
};
/* Buffer for the /dev/zero null byte feed. */
#define ZERO_BUF_SIZE 1024
PRIVATE char dev_zero[ZERO_BUF_SIZE];
#define click_to_round_k(n) \
((unsigned) ((((unsigned long) (n) << CLICK_SHIFT) + 512) / 1024))
/* SEF functions and variables. */
FORWARD _PROTOTYPE( void sef_local_startup, (void) );
FORWARD _PROTOTYPE( int sef_cb_init_fresh, (int type, sef_init_info_t *info) );
/*===========================================================================*
* main *
*===========================================================================*/
PUBLIC int main(void)
{
/* SEF local startup. */
sef_local_startup();
/* Call the generic receive loop. */
driver_task(&m_dtab, DRIVER_STD);
return(OK);
}
/*===========================================================================*
* sef_local_startup *
*===========================================================================*/
PRIVATE void sef_local_startup()
{
/* Register init callbacks. */
sef_setcb_init_fresh(sef_cb_init_fresh);
sef_setcb_init_lu(sef_cb_init_fresh);
sef_setcb_init_restart(sef_cb_init_fresh);
/* Register live update callbacks. */
sef_setcb_lu_prepare(sef_cb_lu_prepare_always_ready);
sef_setcb_lu_state_isvalid(sef_cb_lu_state_isvalid_standard);
/* Let SEF perform startup. */
sef_startup();
}
/*===========================================================================*
* sef_cb_init_fresh *
*===========================================================================*/
PRIVATE int sef_cb_init_fresh(int type, sef_init_info_t *info)
{
/* Initialize the memory driver. */
u32_t ramdev_size;
int i, s;
/* Initialize all minor devices one by one. */
if (OK != (s=sys_getkinfo(&kinfo))) {
panic("Couldn't get kernel information: %d", s);
}
#if 0
/* Map in kernel memory for /dev/kmem. */
m_geom[KMEM_DEV].dv_base = cvul64(kinfo.kmem_base);
m_geom[KMEM_DEV].dv_size = cvul64(kinfo.kmem_size);
if((m_vaddrs[KMEM_DEV] = vm_map_phys(SELF, (void *) kinfo.kmem_base,
kinfo.kmem_size)) == MAP_FAILED) {
printf("MEM: Couldn't map in /dev/kmem.");
}
#endif
/* Ramdisk image built into the memory driver */
m_geom[IMGRD_DEV].dv_base= cvul64(0);
m_geom[IMGRD_DEV].dv_size= cvul64(imgrd_size);
m_vaddrs[IMGRD_DEV] = (vir_bytes) imgrd;
/* Initialize /dev/zero. Simply write zeros into the buffer. */
for (i=0; i<ZERO_BUF_SIZE; i++) {
dev_zero[i] = '\0';
}
for(i = 0; i < NR_DEVS; i++)
openct[i] = 0;
/* Set up memory range for /dev/mem. */
m_geom[MEM_DEV].dv_base = cvul64(0);
m_geom[MEM_DEV].dv_size = cvul64(0xffffffff);
m_vaddrs[MEM_DEV] = (vir_bytes) MAP_FAILED; /* we are not mapping this in. */
return(OK);
}
/*===========================================================================*
* m_name *
*===========================================================================*/
PRIVATE char *m_name()
{
/* Return a name for the current device. */
static char name[] = "memory";
return name;
}
/*===========================================================================*
* m_prepare *
*===========================================================================*/
PRIVATE struct device *m_prepare(device)
int device;
{
/* Prepare for I/O on a device: check if the minor device number is ok. */
if (device < 0 || device >= NR_DEVS) return(NULL);
m_device = device;
return(&m_geom[device]);
}
/*===========================================================================*
* m_transfer *
*===========================================================================*/
PRIVATE int m_transfer(proc_nr, opcode, pos64, iov, nr_req)
int proc_nr; /* process doing the request */
int opcode; /* DEV_GATHER_S or DEV_SCATTER_S */
u64_t pos64; /* offset on device to read or write */
iovec_t *iov; /* pointer to read or write request vector */
unsigned nr_req; /* length of request vector */
{
/* Read or write one the driver's minor devices. */
unsigned count, left, chunk;
vir_bytes user_vir, vir_offset = 0;
struct device *dv;
unsigned long dv_size;
int s, r;
off_t position;
vir_bytes dev_vaddr;
/* ZERO_DEV and NULL_DEV are infinite in size. */
if (m_device != ZERO_DEV && m_device != NULL_DEV && ex64hi(pos64) != 0)
return OK; /* Beyond EOF */
position= cv64ul(pos64);
/* Get minor device number and check for /dev/null. */
dv = &m_geom[m_device];
dv_size = cv64ul(dv->dv_size);
dev_vaddr = m_vaddrs[m_device];
while (nr_req > 0) {
/* How much to transfer and where to / from. */
count = iov->iov_size;
user_vir = iov->iov_addr;
switch (m_device) {
/* No copying; ignore request. */
case NULL_DEV:
if (opcode == DEV_GATHER_S) return(OK); /* always at EOF */
break;
/* Virtual copying. For RAM disks, kernel memory and internal FS. */
default:
case KMEM_DEV:
case RAM_DEV_OLD:
case IMGRD_DEV:
/* Bogus number. */
if(m_device < 0 || m_device >= NR_DEVS) {
return(EINVAL);
}
if(!dev_vaddr || dev_vaddr == (vir_bytes) MAP_FAILED) {
printf("MEM: dev %d not initialized\n", m_device);
return EIO;
}
if (position >= dv_size) return(OK); /* check for EOF */
if (position + count > dv_size) count = dv_size - position;
if (opcode == DEV_GATHER_S) { /* copy actual data */
r=sys_safecopyto(proc_nr, user_vir, vir_offset,
dev_vaddr + position, count, D);
} else {
r=sys_safecopyfrom(proc_nr, user_vir, vir_offset,
dev_vaddr + position, count, D);
}
if(r != OK) {
panic("I/O copy failed: %d", r);
}
break;
/* Physical copying. Only used to access entire memory.
* Transfer one 'page window' at a time.
*/
case MEM_DEV:
{
u32_t pagestart, page_off;
static u32_t pagestart_mapped;
static int any_mapped = 0;
static char *vaddr;
int r;
u32_t subcount;
phys_bytes mem_phys;
if (position >= dv_size)
return(OK); /* check for EOF */
if (position + count > dv_size)
count = dv_size - position;
mem_phys = position;
page_off = mem_phys % I386_PAGE_SIZE;
pagestart = mem_phys - page_off;
/* All memory to the map call has to be page-aligned.
* Don't have to map same page over and over.
*/
if(!any_mapped || pagestart_mapped != pagestart) {
if(any_mapped) {
if(vm_unmap_phys(SELF, vaddr, I386_PAGE_SIZE) != OK)
panic("vm_unmap_phys failed");
any_mapped = 0;
}
vaddr = vm_map_phys(SELF, (void *) pagestart, I386_PAGE_SIZE);
if(vaddr == MAP_FAILED)
r = ENOMEM;
else
r = OK;
if(r != OK) {
printf("memory: vm_map_phys failed\n");
return r;
}
any_mapped = 1;
pagestart_mapped = pagestart;
}
/* how much to be done within this page. */
subcount = I386_PAGE_SIZE-page_off;
if(subcount > count)
subcount = count;
if (opcode == DEV_GATHER_S) { /* copy data */
s=sys_safecopyto(proc_nr, user_vir,
vir_offset, (vir_bytes) vaddr+page_off, subcount, D);
} else {
s=sys_safecopyfrom(proc_nr, user_vir,
vir_offset, (vir_bytes) vaddr+page_off, subcount, D);
}
if(s != OK)
return s;
count = subcount;
break;
}
/* Null byte stream generator. */
case ZERO_DEV:
if (opcode == DEV_GATHER_S) {
size_t suboffset = 0;
left = count;
while (left > 0) {
chunk = (left > ZERO_BUF_SIZE) ? ZERO_BUF_SIZE : left;
s=sys_safecopyto(proc_nr, user_vir,
vir_offset+suboffset, (vir_bytes) dev_zero, chunk, D);
if(s != OK)
return s;
left -= chunk;
suboffset += chunk;
}
}
break;
}
/* Book the number of bytes transferred. */
position += count;
vir_offset += count;
if ((iov->iov_size -= count) == 0) { iov++; nr_req--; vir_offset = 0; }
}
return(OK);
}
/*===========================================================================*
* m_do_open *
*===========================================================================*/
PRIVATE int m_do_open(dp, m_ptr)
struct driver *dp;
message *m_ptr;
{
int r;
/* Check device number on open. */
if (m_prepare(m_ptr->DEVICE) == NULL) return(ENXIO);
if (m_device == MEM_DEV)
{
r = sys_enable_iop(m_ptr->IO_ENDPT);
if (r != OK)
{
printf("m_do_open: sys_enable_iop failed for %d: %d\n",
m_ptr->IO_ENDPT, r);
return r;
}
}
if(m_device < 0 || m_device >= NR_DEVS) {
panic("wrong m_device: %d", m_device);
}
openct[m_device]++;
return(OK);
}
/*===========================================================================*
* m_do_close *
*===========================================================================*/
PRIVATE int m_do_close(dp, m_ptr)
struct driver *dp;
message *m_ptr;
{
int r;
if (m_prepare(m_ptr->DEVICE) == NULL) return(ENXIO);
if(m_device < 0 || m_device >= NR_DEVS) {
panic("wrong m_device: %d", m_device);
}
if(openct[m_device] < 1) {
panic("closed too often");
}
openct[m_device]--;
/* Special case: free initial ramdisk after it's been unmounted once. */
if(m_device == IMGRD_DEV && openct[m_device] == 0 && m_vaddrs[IMGRD_DEV]) {
vir_bytes vaddr, vlen;
vaddr = m_vaddrs[IMGRD_DEV];
vlen = imgrd_size;
/* Align `inwards' so as to not unmap more than the initial
* ramdisk image.
*/
if(vaddr % PAGE_SIZE) {
vir_bytes o = PAGE_SIZE - (vaddr % PAGE_SIZE);
vlen -= o;
vaddr += o;
}
if(vlen % PAGE_SIZE) {
vlen -= vlen % PAGE_SIZE;
}
munmap((void *) vaddr, vlen);
m_geom[IMGRD_DEV].dv_base= cvul64(0);
m_geom[IMGRD_DEV].dv_size= cvul64(0);
m_vaddrs[IMGRD_DEV] = 0;
}
return(OK);
}
/*===========================================================================*
* m_ioctl *
*===========================================================================*/
PRIVATE int m_ioctl(dp, m_ptr)
struct driver *dp; /* pointer to driver structure */
message *m_ptr; /* pointer to control message */
{
/* I/O controls for the memory driver. Currently there is one I/O control:
* - MIOCRAMSIZE: to set the size of the RAM disk.
*/
struct device *dv;
switch (m_ptr->REQUEST) {
case MIOCRAMSIZE: {
/* Someone wants to create a new RAM disk with the given size. */
u32_t ramdev_size;
int s, dev;
void *mem;
/* A ramdisk can be created only once, and only on RAM disk device. */
dev = m_ptr->DEVICE;
if(dev < 0 || dev >= NR_DEVS) {
printf("MEM: MIOCRAMSIZE: %d not a valid device\n", dev);
}
if((dev < RAM_DEV_FIRST || dev > RAM_DEV_LAST) && dev != RAM_DEV_OLD) {
printf("MEM: MIOCRAMSIZE: %d not a ramdisk\n", dev);
}
if ((dv = m_prepare(dev)) == NULL) return(ENXIO);
/* Get request structure */
s= sys_safecopyfrom(m_ptr->IO_ENDPT, (vir_bytes)m_ptr->IO_GRANT,
0, (vir_bytes)&ramdev_size, sizeof(ramdev_size), D);
if (s != OK)
return s;
if(m_vaddrs[dev] && !cmp64(dv->dv_size, cvul64(ramdev_size))) {
return(OK);
}
/* openct is 1 for the ioctl(). */
if(openct[dev] != 1) {
printf("MEM: MIOCRAMSIZE: %d in use (count %d)\n",
dev, openct[dev]);
return(EBUSY);
}
if(m_vaddrs[dev]) {
u32_t size;
if(ex64hi(dv->dv_size)) {
panic("huge old ramdisk");
}
size = ex64lo(dv->dv_size);
munmap((void *) m_vaddrs[dev], size);
m_vaddrs[dev] = (vir_bytes) NULL;
}
#if DEBUG
printf("MEM:%d: allocating ramdisk of size 0x%x\n", dev, ramdev_size);
#endif
/* Try to allocate a piece of memory for the RAM disk. */
if((mem = mmap(NULL, ramdev_size, PROT_READ|PROT_WRITE,
MAP_PREALLOC|MAP_ANON, -1, 0)) == MAP_FAILED) {
printf("MEM: failed to get memory for ramdisk\n");
return(ENOMEM);
}
m_vaddrs[dev] = (vir_bytes) mem;
dv->dv_size = cvul64(ramdev_size);
break;
}
default:
return(do_diocntl(&m_dtab, m_ptr));
}
return(OK);
}
/*===========================================================================*
* m_geometry *
*===========================================================================*/
PRIVATE void m_geometry(entry)
struct partition *entry;
{
/* Memory devices don't have a geometry, but the outside world insists. */
entry->cylinders = div64u(m_geom[m_device].dv_size, SECTOR_SIZE) / (64 * 32);
entry->heads = 64;
entry->sectors = 32;
}
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