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minix/drivers/memory/memory.c
Ben Gras 7336a67dfe retire PUBLIC, PRIVATE and FORWARD
2012-03-25 21:58:14 +02:00

623 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/chardriver.h>
#include <minix/blockdriver.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 */
static struct device m_geom[NR_DEVS]; /* base and size of each device */
static vir_bytes m_vaddrs[NR_DEVS];
static dev_t m_device; /* current minor character device */
static int openct[NR_DEVS];
static struct device *m_prepare(dev_t device);
static int m_transfer(endpoint_t endpt, int opcode, u64_t position,
iovec_t *iov, unsigned int nr_req, endpoint_t user_endpt, unsigned int
flags);
static int m_do_open(message *m_ptr);
static int m_do_close(message *m_ptr);
static struct device *m_block_part(dev_t minor);
static int m_block_transfer(dev_t minor, int do_write, u64_t position,
endpoint_t endpt, iovec_t *iov, unsigned int nr_req, int flags);
static int m_block_open(dev_t minor, int access);
static int m_block_close(dev_t minor);
static int m_block_ioctl(dev_t minor, unsigned int request, endpoint_t
endpt, cp_grant_id_t grant);
/* Entry points to the CHARACTER part of this driver. */
static struct chardriver m_cdtab = {
m_do_open, /* open or mount */
m_do_close, /* nothing on a close */
nop_ioctl, /* no I/O control */
m_prepare, /* prepare for I/O on a given minor device */
m_transfer, /* do the I/O */
nop_cleanup, /* no need to clean up */
nop_alarm, /* no alarms */
nop_cancel, /* no blocking operations */
nop_select, /* select not supported */
NULL /* other messages not supported */
};
/* Entry points to the BLOCK part of this driver. */
static struct blockdriver m_bdtab = {
BLOCKDRIVER_TYPE_DISK,/* handle partition requests */
m_block_open, /* open or mount */
m_block_close, /* nothing on a close */
m_block_transfer, /* do the I/O */
m_block_ioctl, /* ram disk I/O control */
NULL, /* no need to clean up */
m_block_part, /* return partition information */
NULL, /* no geometry */
NULL, /* no interrupt processing */
NULL, /* no alarm processing */
NULL, /* no processing of other messages */
NULL /* no threading support */
};
/* Buffer for the /dev/zero null byte feed. */
#define ZERO_BUF_SIZE 1024
static char dev_zero[ZERO_BUF_SIZE];
#define click_to_round_k(n) \
((unsigned) ((((unsigned long) (n) << CLICK_SHIFT) + 512) / 1024))
/* SEF functions and variables. */
static void sef_local_startup(void);
static int sef_cb_init_fresh(int type, sef_init_info_t *info);
/*===========================================================================*
* main *
*===========================================================================*/
int main(void)
{
message msg;
int r, ipc_status;
/* SEF local startup. */
sef_local_startup();
/* The receive loop. */
for (;;) {
if ((r = driver_receive(ANY, &msg, &ipc_status)) != OK)
panic("memory: driver_receive failed (%d)", r);
if (IS_BDEV_RQ(msg.m_type))
blockdriver_process(&m_bdtab, &msg, ipc_status);
else
chardriver_process(&m_cdtab, CHARDRIVER_SYNC, &msg,
ipc_status);
}
return(OK);
}
/*===========================================================================*
* sef_local_startup *
*===========================================================================*/
static 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 *
*===========================================================================*/
static int sef_cb_init_fresh(int UNUSED(type), sef_init_info_t *UNUSED(info))
{
/* Initialize the memory driver. */
int i;
#if 0
struct kinfo kinfo; /* kernel information */
int s;
if (OK != (s=sys_getkinfo(&kinfo))) {
panic("Couldn't get kernel information: %d", s);
}
/* 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_is_block *
*===========================================================================*/
static int m_is_block(dev_t minor)
{
/* Return TRUE iff the given minor device number is for a block device. */
switch (minor) {
case MEM_DEV:
case KMEM_DEV:
case NULL_DEV:
case ZERO_DEV:
return FALSE;
default:
return TRUE;
}
}
/*===========================================================================*
* m_prepare *
*===========================================================================*/
static struct device *m_prepare(dev_t device)
{
/* Prepare for I/O on a device: check if the minor device number is ok. */
if (device >= NR_DEVS || m_is_block(device)) return(NULL);
m_device = device;
return(&m_geom[device]);
}
/*===========================================================================*
* m_transfer *
*===========================================================================*/
static int m_transfer(
endpoint_t endpt, /* endpoint of grant owner */
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 int nr_req, /* length of request vector */
endpoint_t UNUSED(user_endpt),/* endpoint of user process */
unsigned int UNUSED(flags)
)
{
/* Read or write one the driver's character devices. */
unsigned count, left, chunk;
vir_bytes vir_offset = 0;
struct device *dv;
unsigned long dv_size;
int s, r;
off_t position;
cp_grant_id_t grant;
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;
grant = (cp_grant_id_t) 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 kernel memory. */
default:
case KMEM_DEV:
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(endpt, grant, vir_offset,
dev_vaddr + position, count, D);
} else {
r=sys_safecopyfrom(endpt, grant, 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(endpt, grant,
vir_offset, (vir_bytes) vaddr+page_off, subcount, D);
} else {
s=sys_safecopyfrom(endpt, grant,
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(endpt, grant,
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 *
*===========================================================================*/
static int m_do_open(message *m_ptr)
{
/* Open a memory character device. */
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->USER_ENDPT);
if (r != OK)
{
printf("m_do_open: sys_enable_iop failed for %d: %d\n",
m_ptr->USER_ENDPT, r);
return r;
}
}
openct[m_device]++;
return(OK);
}
/*===========================================================================*
* m_do_close *
*===========================================================================*/
static int m_do_close(message *m_ptr)
{
/* Close a memory character device. */
if (m_prepare(m_ptr->DEVICE) == NULL) return(ENXIO);
if(openct[m_device] < 1) {
printf("MEMORY: closing unopened device %d\n", m_device);
return(EINVAL);
}
openct[m_device]--;
return(OK);
}
/*===========================================================================*
* m_block_part *
*===========================================================================*/
static struct device *m_block_part(dev_t minor)
{
/* Prepare for I/O on a device: check if the minor device number is ok. */
if (minor >= NR_DEVS || !m_is_block(minor)) return(NULL);
return(&m_geom[minor]);
}
/*===========================================================================*
* m_block_transfer *
*===========================================================================*/
static int m_block_transfer(
dev_t minor, /* minor device number */
int do_write, /* read or write? */
u64_t pos64, /* offset on device to read or write */
endpoint_t endpt, /* process doing the request */
iovec_t *iov, /* pointer to read or write request vector */
unsigned int nr_req, /* length of request vector */
int UNUSED(flags) /* transfer flags */
)
{
/* Read or write one the driver's block devices. */
unsigned count;
vir_bytes vir_offset = 0;
struct device *dv;
unsigned long dv_size;
int r;
off_t position;
vir_bytes dev_vaddr;
cp_grant_id_t grant;
ssize_t total = 0;
/* Get minor device information. */
if ((dv = m_block_part(minor)) == NULL) return(ENXIO);
dv_size = cv64ul(dv->dv_size);
dev_vaddr = m_vaddrs[minor];
if (ex64hi(pos64) != 0)
return OK; /* Beyond EOF */
position= cv64ul(pos64);
while (nr_req > 0) {
/* How much to transfer and where to / from. */
count = iov->iov_size;
grant = (cp_grant_id_t) iov->iov_addr;
/* Virtual copying. For RAM disks and internal FS. */
if(!dev_vaddr || dev_vaddr == (vir_bytes) MAP_FAILED) {
printf("MEM: dev %d not initialized\n", minor);
return EIO;
}
if (position >= dv_size) return(total); /* check for EOF */
if (position + count > dv_size) count = dv_size - position;
if (!do_write) { /* copy actual data */
r=sys_safecopyto(endpt, grant, vir_offset,
dev_vaddr + position, count, D);
} else {
r=sys_safecopyfrom(endpt, grant, vir_offset,
dev_vaddr + position, count, D);
}
if(r != OK) {
panic("I/O copy failed: %d", r);
}
/* Book the number of bytes transferred. */
position += count;
vir_offset += count;
total += count;
if ((iov->iov_size -= count) == 0) { iov++; nr_req--; vir_offset = 0; }
}
return(total);
}
/*===========================================================================*
* m_block_open *
*===========================================================================*/
static int m_block_open(dev_t minor, int UNUSED(access))
{
/* Open a memory block device. */
if (m_block_part(minor) == NULL) return(ENXIO);
openct[minor]++;
return(OK);
}
/*===========================================================================*
* m_block_close *
*===========================================================================*/
static int m_block_close(dev_t minor)
{
/* Close a memory block device. */
if (m_block_part(minor) == NULL) return(ENXIO);
if(openct[minor] < 1) {
printf("MEMORY: closing unopened device %d\n", minor);
return(EINVAL);
}
openct[minor]--;
#if 0
/* Special case: free initial ramdisk after it's been unmounted once. */
if(minor == IMGRD_DEV && openct[minor] == 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;
}
minix_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;
}
#endif
return(OK);
}
/*===========================================================================*
* m_block_ioctl *
*===========================================================================*/
static int m_block_ioctl(dev_t minor, unsigned int request, endpoint_t endpt,
cp_grant_id_t grant)
{
/* I/O controls for the block devices of the memory driver. Currently there is
* one I/O control specific to the memory driver:
* - MIOCRAMSIZE: to set the size of the RAM disk.
*/
struct device *dv;
u32_t ramdev_size;
int s;
void *mem;
if (request != MIOCRAMSIZE)
return EINVAL;
/* Someone wants to create a new RAM disk with the given size.
* A ramdisk can be created only once, and only on RAM disk device.
*/
if ((dv = m_block_part(minor)) == NULL) return ENXIO;
if((minor < RAM_DEV_FIRST || minor > RAM_DEV_LAST) && minor != RAM_DEV_OLD) {
printf("MEM: MIOCRAMSIZE: %d not a ramdisk\n", minor);
return EINVAL;
}
/* Get request structure */
s= sys_safecopyfrom(endpt, grant, 0, (vir_bytes)&ramdev_size,
sizeof(ramdev_size), D);
if (s != OK)
return s;
if(m_vaddrs[minor] && !cmp64(dv->dv_size, cvul64(ramdev_size))) {
return(OK);
}
/* openct is 1 for the ioctl(). */
if(openct[minor] != 1) {
printf("MEM: MIOCRAMSIZE: %d in use (count %d)\n",
minor, openct[minor]);
return(EBUSY);
}
if(m_vaddrs[minor]) {
u32_t size;
if(ex64hi(dv->dv_size)) {
panic("huge old ramdisk");
}
size = ex64lo(dv->dv_size);
minix_munmap((void *) m_vaddrs[minor], size);
m_vaddrs[minor] = (vir_bytes) NULL;
}
#if DEBUG
printf("MEM:%d: allocating ramdisk of size 0x%x\n", minor, ramdev_size);
#endif
/* Try to allocate a piece of memory for the RAM disk. */
if((mem = minix_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[minor] = (vir_bytes) mem;
dv->dv_size = cvul64(ramdev_size);
return(OK);
}
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