minix3/drivers/storage/memory/memory.c

602 lines
17 KiB
C

/* 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 <assert.h>
#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 <machine/vmparam.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 int openct[NR_DEVS];
static ssize_t m_char_read(devminor_t minor, u64_t position, endpoint_t endpt,
cp_grant_id_t grant, size_t size, int flags, cdev_id_t id);
static ssize_t m_char_write(devminor_t minor, u64_t position, endpoint_t endpt,
cp_grant_id_t grant, size_t size, int flags, cdev_id_t id);
static int m_char_open(devminor_t minor, int access, endpoint_t user_endpt);
static int m_char_close(devminor_t minor);
static struct device *m_block_part(devminor_t minor);
static ssize_t m_block_transfer(devminor_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(devminor_t minor, int access);
static int m_block_close(devminor_t minor);
static int m_block_ioctl(devminor_t minor, unsigned long request, endpoint_t
endpt, cp_grant_id_t grant, endpoint_t user_endpt);
/* Entry points to the CHARACTER part of this driver. */
static struct chardriver m_cdtab = {
.cdr_open = m_char_open, /* open device */
.cdr_close = m_char_close, /* close device */
.cdr_read = m_char_read, /* read from device */
.cdr_write = m_char_write /* write to device */
};
/* Entry points to the BLOCK part of this driver. */
static struct blockdriver m_bdtab = {
.bdr_type = BLOCKDRIVER_TYPE_DISK,/* handle partition requests */
.bdr_open = m_block_open, /* open device */
.bdr_close = m_block_close, /* nothing on a close */
.bdr_transfer = m_block_transfer, /* do the I/O */
.bdr_ioctl = m_block_ioctl, /* ram disk I/O control */
.bdr_part = m_block_part /* return partition information */
};
/* 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, &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 = kinfo.kmem_base;
m_geom[KMEM_DEV].dv_size = 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= 0;
m_geom[IMGRD_DEV].dv_size= imgrd_size;
m_vaddrs[IMGRD_DEV] = (vir_bytes) imgrd;
for(i = 0; i < NR_DEVS; i++)
openct[i] = 0;
/* Set up memory range for /dev/mem. */
m_geom[MEM_DEV].dv_base = 0;
m_geom[MEM_DEV].dv_size = 0xffffffffULL;
m_vaddrs[MEM_DEV] = (vir_bytes) MAP_FAILED; /* we are not mapping this in. */
return(OK);
}
/*===========================================================================*
* m_is_block *
*===========================================================================*/
static int m_is_block(devminor_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_transfer_kmem *
*===========================================================================*/
static ssize_t m_transfer_kmem(devminor_t minor, int do_write, u64_t position,
endpoint_t endpt, cp_grant_id_t grant, size_t size)
{
/* Transfer from or to the KMEM device. */
u64_t dv_size, dev_vaddr;
int r;
dv_size = m_geom[minor].dv_size;
dev_vaddr = m_vaddrs[minor];
if (!dev_vaddr || dev_vaddr == (vir_bytes) MAP_FAILED) {
printf("MEM: dev %d not initialized\n", minor);
return EIO;
}
if (position >= dv_size) return 0; /* check for EOF */
if (position + size > dv_size) size = dv_size - position;
if (!do_write) /* copy actual data */
r = sys_safecopyto(endpt, grant, 0, dev_vaddr + position, size);
else
r = sys_safecopyfrom(endpt, grant, 0, dev_vaddr + position, size);
return (r != OK) ? r : size;
}
/*===========================================================================*
* m_transfer_mem *
*===========================================================================*/
static ssize_t m_transfer_mem(devminor_t minor, int do_write, u64_t position,
endpoint_t endpt, cp_grant_id_t grant, size_t size)
{
/* Transfer from or to the MEM device. */
static int any_mapped = 0;
static phys_bytes pagestart_mapped;
static char *vaddr;
phys_bytes mem_phys, pagestart;
size_t off, page_off, subcount;
u64_t dv_size;
int r;
dv_size = m_geom[minor].dv_size;
if (position >= dv_size) return 0; /* check for EOF */
if (position + size > dv_size) size = dv_size - position;
/* Physical copying. Only used to access entire memory.
* Transfer one 'page window' at a time.
*/
off = 0;
while (off < size) {
mem_phys = (phys_bytes) position;
page_off = (size_t) (mem_phys % 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, PAGE_SIZE) != OK)
panic("vm_unmap_phys failed");
any_mapped = 0;
}
vaddr = vm_map_phys(SELF, (void *) pagestart, PAGE_SIZE);
if (vaddr == MAP_FAILED) {
printf("memory: vm_map_phys failed\n");
return ENOMEM;
}
any_mapped = 1;
pagestart_mapped = pagestart;
}
/* how much to be done within this page. */
subcount = PAGE_SIZE - page_off;
if (subcount > size)
subcount = size;
if (!do_write) /* copy data */
r = sys_safecopyto(endpt, grant, off,
(vir_bytes) vaddr + page_off, subcount);
else
r = sys_safecopyfrom(endpt, grant, off,
(vir_bytes) vaddr + page_off, subcount);
if (r != OK)
return r;
position += subcount;
off += subcount;
}
return off;
}
/*===========================================================================*
* m_char_read *
*===========================================================================*/
static ssize_t m_char_read(devminor_t minor, u64_t position, endpoint_t endpt,
cp_grant_id_t grant, size_t size, int UNUSED(flags),
cdev_id_t UNUSED(id))
{
/* Read from one of the driver's character devices. */
ssize_t r;
/* Check if the minor device number is ok. */
if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO;
switch (minor) {
case NULL_DEV:
r = 0; /* always at EOF */
break;
case ZERO_DEV:
/* Fill the target area with zeroes. In fact, let the kernel do it! */
if ((r = sys_safememset(endpt, grant, 0, '\0', size)) == OK)
r = size;
break;
case KMEM_DEV:
r = m_transfer_kmem(minor, FALSE, position, endpt, grant, size);
break;
case MEM_DEV:
r = m_transfer_mem(minor, FALSE, position, endpt, grant, size);
break;
default:
panic("unknown character device %d", minor);
}
return r;
}
/*===========================================================================*
* m_char_write *
*===========================================================================*/
static ssize_t m_char_write(devminor_t minor, u64_t position, endpoint_t endpt,
cp_grant_id_t grant, size_t size, int UNUSED(flags),
cdev_id_t UNUSED(id))
{
/* Write to one of the driver's character devices. */
ssize_t r;
/* Check if the minor device number is ok. */
if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO;
switch (minor) {
case NULL_DEV:
case ZERO_DEV:
r = size; /* just eat everything */
break;
case KMEM_DEV:
r = m_transfer_kmem(minor, TRUE, position, endpt, grant, size);
break;
case MEM_DEV:
r = m_transfer_mem(minor, TRUE, position, endpt, grant, size);
break;
default:
panic("unknown character device %d", minor);
}
return r;
}
/*===========================================================================*
* m_char_open *
*===========================================================================*/
static int m_char_open(devminor_t minor, int access, endpoint_t user_endpt)
{
/* Open a memory character device. */
/* Check if the minor device number is ok. */
if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO;
#if defined(__i386__)
if (minor == MEM_DEV)
{
int r = sys_enable_iop(user_endpt);
if (r != OK)
{
printf("m_char_open: sys_enable_iop failed for %d: %d\n",
user_endpt, r);
return r;
}
}
#endif
openct[minor]++;
return(OK);
}
/*===========================================================================*
* m_char_close *
*===========================================================================*/
static int m_char_close(devminor_t minor)
{
/* Close a memory character device. */
if (minor < 0 || minor >= NR_DEVS || m_is_block(minor)) return ENXIO;
if(openct[minor] < 1) {
printf("MEMORY: closing unopened device %d\n", minor);
return(EINVAL);
}
openct[minor]--;
return(OK);
}
/*===========================================================================*
* m_block_part *
*===========================================================================*/
static struct device *m_block_part(devminor_t minor)
{
/* Prepare for I/O on a device: check if the minor device number is ok. */
if (minor < 0 || minor >= NR_DEVS || !m_is_block(minor)) return(NULL);
return(&m_geom[minor]);
}
/*===========================================================================*
* m_block_transfer *
*===========================================================================*/
static int m_block_transfer(
devminor_t minor, /* minor device number */
int do_write, /* read or write? */
u64_t position, /* 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;
u64_t dv_size;
int r;
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 = dv->dv_size;
dev_vaddr = m_vaddrs[minor];
if (ex64hi(position) != 0)
return OK; /* Beyond EOF */
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);
} else {
r=sys_safecopyfrom(endpt, grant, vir_offset,
dev_vaddr + position, count);
}
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(devminor_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(devminor_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]--;
return(OK);
}
/*===========================================================================*
* m_block_ioctl *
*===========================================================================*/
static int m_block_ioctl(devminor_t minor, unsigned long request,
endpoint_t endpt, cp_grant_id_t grant, endpoint_t UNUSED(user_endpt))
{
/* 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;
int is_imgrd = 0;
if (request != MIOCRAMSIZE)
return EINVAL;
if(minor == IMGRD_DEV)
is_imgrd = 1;
/* 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 && !is_imgrd) {
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));
if (s != OK)
return s;
if(is_imgrd)
ramdev_size = 0;
if(m_vaddrs[minor] && dv->dv_size == (u64_t) 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 a, o;
u64_t size;
int r;
if(ex64hi(dv->dv_size)) {
panic("huge old ramdisk");
}
size = dv->dv_size;
a = m_vaddrs[minor];
if((o = a % PAGE_SIZE)) {
vir_bytes l = PAGE_SIZE - o;
a += l;
size -= l;
}
size = rounddown(size, PAGE_SIZE);
r = munmap((void *) a, size);
if(r != OK) {
printf("memory: WARNING: munmap failed: %d\n", r);
}
m_vaddrs[minor] = (vir_bytes) NULL;
dv->dv_size = 0;
}
#if DEBUG
printf("MEM:%d: allocating ramdisk of size 0x%x\n", minor, ramdev_size);
#endif
mem = NULL;
/* Try to allocate a piece of memory for the RAM disk. */
if(ramdev_size > 0 &&
(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[minor] = (vir_bytes) mem;
dv->dv_size = ramdev_size;
return(OK);
}