/*
* Xpram.c -- the S/390 expanded memory RAM-disk
*
* significant parts of this code are based on
* the sbull device driver presented in
* A. Rubini: Linux Device Drivers
*
* Author of XPRAM specific coding: Reinhard Buendgen
* buendgen@de.ibm.com
*
* External interfaces:
* Interfaces to linux kernel
* xpram_setup: read kernel parameters (see init/main.c)
* xpram_init: initialize device driver (see drivers/block/ll_rw_blk.c)
* Module interfaces
* init_module
* cleanup_module
* Device specific file operations
* xpram_iotcl
* xpram_open
* xpram_release
*
* "ad-hoc" partitioning:
* the expanded memory can be partitioned among several devices
* (with different minors). The partitioning set up can be
* set by kernel or module parameters (int devs & int sizes[])
*
* module parameters: devs= and sizes=
* kernel parameters: xpram_parts=
* note: I did not succeed in parsing numbers
* for module parameters of type string "s" ?!?
*
* Other kenel files/modules affected(gerp for "xpram" or "XPRAM":
* drivers/s390/Config.in
* drivers/s390/block/Makefile
* include/linux/blk.h
* include/linux/major.h
* init/main.c
* drivers/block//ll_rw_blk.c
*
*
* Potential future improvements:
* request clustering: first coding started not yet tested or integrated
* I doubt that it really pays off
* generic hard disk support to replace ad-hoc partitioning
*
* Tested with 2.2.14 (under VM)
*/
#ifdef MODULE
# ifndef __KERNEL__
# define __KERNEL__
# endif
# define __NO_VERSION__ /* don't define kernel_version in module.h */
#endif /* MODULE */
#include <linux/module.h>
#include <linux/version.h>
#ifdef MODULE
char kernel_version [] = UTS_RELEASE;
#endif
#if (LINUX_VERSION_CODE > KERNEL_VERSION(2,3,98))
# define XPRAM_VERSION 24
#else
# define XPRAM_VERSION 22
#endif
#if (XPRAM_VERSION == 24)
# include <linux/config.h>
# include <linux/init.h>
#endif /* V24 */
#include <linux/sched.h>
#include <linux/kernel.h> /* printk() */
#include <linux/slab.h> /* kmalloc() */
#if (XPRAM_VERSION == 24)
# include <linux/devfs_fs_kernel.h>
#endif /* V24 */
#include <linux/fs.h> /* everything... */
#include <linux/errno.h> /* error codes */
#include <linux/timer.h>
#include <linux/types.h> /* size_t */
#include <linux/ctype.h> /* isdigit, isxdigit */
#include <linux/fcntl.h> /* O_ACCMODE */
#include <linux/hdreg.h> /* HDIO_GETGEO */
#include <asm/system.h> /* cli(), *_flags */
#include <asm/uaccess.h> /* put_user */
#if (XPRAM_VERSION == 24)
#define MAJOR_NR xpram_major /* force definitions on in blk.h */
int xpram_major; /* must be declared before including blk.h */
devfs_handle_t xpram_devfs_handle;
#define DEVICE_NR(device) MINOR(device) /* xpram has no partition bits */
#define DEVICE_NAME "xpram" /* name for messaging */
#define DEVICE_INTR xpram_intrptr /* pointer to the bottom half */
#define DEVICE_NO_RANDOM /* no entropy to contribute */
#define DEVICE_OFF(d) /* do-nothing */
#include <linux/blk.h>
#include "xpram.h" /* local definitions */
__setup("xpram_parts=", xpram_setup);
#endif /* V24 */
/*
define the debug levels:
- 0 No debugging output to console or syslog
- 1 Log internal errors to syslog, ignore check conditions
- 2 Log internal errors and check conditions to syslog
- 3 Log internal errors to console, log check conditions to syslog
- 4 Log internal errors and check conditions to console
- 5 panic on internal errors, log check conditions to console
- 6 panic on both, internal errors and check conditions
*/
#define XPRAM_DEBUG 4
#define PRINTK_HEADER XPRAM_NAME
#if XPRAM_DEBUG > 0
#define PRINT_DEBUG(x...) printk ( KERN_DEBUG PRINTK_HEADER "debug:" x )
#define PRINT_INFO(x...) printk ( KERN_INFO PRINTK_HEADER "info:" x )
#define PRINT_WARN(x...) printk ( KERN_WARNING PRINTK_HEADER "warning:" x )
#define PRINT_ERR(x...) printk ( KERN_ERR PRINTK_HEADER "error:" x )
#define PRINT_FATAL(x...) panic ( PRINTK_HEADER "panic:"x )
#else
#define PRINT_DEBUG(x...) printk ( KERN_DEBUG PRINTK_HEADER "debug:" x )
#define PRINT_INFO(x...) printk ( KERN_DEBUG PRINTK_HEADER "info:" x )
#define PRINT_WARN(x...) printk ( KERN_DEBUG PRINTK_HEADER "warning:" x )
#define PRINT_ERR(x...) printk ( KERN_DEBUG PRINTK_HEADER "error:" x )
#define PRINT_FATAL(x...) printk ( KERN_DEBUG PRINTK_HEADER "panic:" x )
#endif
#if (XPRAM_VERSION == 22)
#define MAJOR_NR xpram_major /* force definitions on in blk.h */
int xpram_major; /* must be declared before including blk.h */
#define DEVICE_NR(device) MINOR(device) /* xpram has no partition bits */
#define DEVICE_NAME "xpram" /* name for messaging */
#define DEVICE_INTR xpram_intrptr /* pointer to the bottom half */
#define DEVICE_NO_RANDOM /* no entropy to contribute */
#define DEVICE_OFF(d) /* do-nothing */
#define DEVICE_REQUEST *xpram_dummy_device_request /* dummy function variable
* to prevent warnings
*/#include <linux/blk.h>
#include "xpram.h" /* local definitions */
#endif /* V22 */
/*
* Non-prefixed symbols are static. They are meant to be assigned at
* load time. Prefixed symbols are not static, so they can be used in
* debugging. They are hidden anyways by register_symtab() unless
* XPRAM_DEBUG is defined.
*/
static int major = XPRAM_MAJOR;
static int devs = XPRAM_DEVS;
static int rahead = XPRAM_RAHEAD;
static int sizes[XPRAM_MAX_DEVS] = { 0, };
static int blksize = XPRAM_BLKSIZE;
static int hardsect = XPRAM_HARDSECT;
int xpram_devs, xpram_rahead;
int xpram_blksize, xpram_hardsect;
int xpram_mem_avail = 0;
unsigned int xpram_sizes[XPRAM_MAX_DEVS];
MODULE_PARM(devs,"i");
MODULE_PARM(sizes,"1-" __MODULE_STRING(XPRAM_MAX_DEVS) "i");
MODULE_PARM_DESC(devs, "number of devices (\"partitions\"), " \
"the default is " __MODULE_STRING(XPRAM_DEVS) "\n");
MODULE_PARM_DESC(sizes, "list of device (partition) sizes " \
"the defaults are 0s \n" \
"All devices with size 0 equally partition the "
"remaining space on the expanded strorage not "
"claimed by explicit sizes\n");
MODULE_LICENSE("GPL");
/* The following items are obtained through kmalloc() in init_module() */
Xpram_Dev *xpram_devices = NULL;
int *xpram_blksizes = NULL;
int *xpram_hardsects = NULL;
int *xpram_offsets = NULL; /* partition offsets */
#define MIN(x,y) ((x) < (y) ? (x) : (y))
#define MAX(x,y) ((x) > (y) ? (x) : (y))
/*
* compute nearest multiple of 4 , argument must be non-negative
* the macros used depends on XPRAM_KB_IN_PG = 4
*/
#define NEXT4(x) ((x & 0x3) ? (x+4-(x &0x3)) : (x)) /* increment if needed */
#define LAST4(x) ((x & 0x3) ? (x-4+(x & 0x3)) : (x)) /* decrement if needed */
#if 0 /* this is probably not faster than the previous code */
#define NEXT4(x) ((((x-1)>>2)>>2)+4) /* increment if needed */
#define LAST4(x) (((x+3)>>2)<<2) /* decrement if needed */
#endif
/* integer formats */
#define XPRAM_INVALF -1 /* invalid */
#define XPRAM_HEXF 0 /* hexadecimal */
#define XPRAM_DECF 1 /* decimal */
/*
* parsing operations (needed for kernel parameter parsing)
*/
/* -------------------------------------------------------------------------
* sets the string pointer after the next comma
*
* argument: strptr pointer to string
* side effect: strptr points to endof string or to position of the next
* comma
* ------------------------------------------------------------------------*/
static void
xpram_scan_to_next_comma (char **strptr)
{
while ( ((**strptr) != ',') && (**strptr) )
(*strptr)++;
}
/* -------------------------------------------------------------------------
* interpret character as hex-digit
*
* argument: c charcter
* result: c interpreted as hex-digit
* note: can be used to read digits for any base <= 16
* ------------------------------------------------------------------------*/
static int
xpram_get_hexdigit (char c)
{
if ((c >= '0') && (c <= '9'))
return c - '0';
if ((c >= 'a') && (c <= 'f'))
return c + 10 - 'a';
if ((c >= 'A') && (c <= 'F'))
return c + 10 - 'A';
return -1;
}
/*--------------------------------------------------------------------------
* Check format of unsigned integer
*
* Argument: strptr pointer to string
* result: -1 if strptr does not start with a digit
* (does not start an integer)
* 0 if strptr starts a positive hex-integer with "0x"
* 1 if strptr start a positive decimal integer
*
* side effect: if strptr start a positive hex-integer then strptr is
* set to the character after the "0x"
*-------------------------------------------------------------------------*/
static int
xpram_int_format(char **strptr)
{
if ( !isdigit(**strptr) )
return XPRAM_INVALF;
if ( (**strptr == '0')
&& ( (*((*strptr)+1) == 'x') || (*((*strptr) +1) == 'X') )
&& isxdigit(*((*strptr)+2)) ) {
*strptr=(*strptr)+2;
return XPRAM_HEXF;
} else return XPRAM_DECF;
}
/*--------------------------------------------------------------------------
* Read non-negative decimal integer
*
* Argument: strptr pointer to string starting with a non-negative integer
* in decimal format
* result: the value of theinitial integer pointed to by strptr
*
* side effect: strptr is set to the first character following the integer
*-------------------------------------------------------------------------*/
static int
xpram_read_decint (char ** strptr)
{
int res=0;
while ( isdigit(**strptr) ) {
res = (res*10) + xpram_get_hexdigit(**strptr);
(*strptr)++;
}
return res;
}
/*--------------------------------------------------------------------------
* Read non-negative hex-integer
*
* Argument: strptr pointer to string starting with a non-negative integer
* in hexformat (without "0x" prefix)
* result: the value of the initial integer pointed to by strptr
*
* side effect: strptr is set to the first character following the integer
*-------------------------------------------------------------------------*/
static int
xpram_read_hexint (char ** strptr)
{
int res=0;
while ( isxdigit(**strptr) ) {
res = (res<<4) + xpram_get_hexdigit(**strptr);
(*strptr)++;
}
return res;
}
/*--------------------------------------------------------------------------
* Read non-negative integer
*
* Argument: strptr pointer to string starting with a non-negative integer
(either in decimal- or in hex-format
* result: the value of the initial integer pointed to by strptr
* in case of a parsing error the result is -EINVAL
*
* side effect: strptr is set to the first character following the integer
*-------------------------------------------------------------------------*/
static int
xpram_read_int (char ** strptr)
{
switch ( xpram_int_format(strptr) ) {
case XPRAM_INVALF: return -EINVAL;
case XPRAM_HEXF: return xpram_read_hexint(strptr);
case XPRAM_DECF: return xpram_read_decint(strptr);
default: return -EINVAL;
}
}
/*--------------------------------------------------------------------------
* Read size
*
* Argument: strptr pointer to string starting with a non-negative integer
* followed optionally by a size modifier:
* k or K for kilo (default),
* m or M for mega
* g or G for giga
* result: the value of the initial integer pointed to by strptr
* multiplied by the modifier value devided by 1024
* in case of a parsing error the result is -EINVAL
*
* side effect: strptr is set to the first character following the size
*-------------------------------------------------------------------------*/
static int
xpram_read_size (char ** strptr)
{
int res;
res=xpram_read_int(strptr);
if ( res < 0 )return res;
switch ( **strptr ) {
case 'g':
case 'G': res=res*1024;
case 'm':
case 'M': res=res*1024;
case 'k' :
case 'K' : (* strptr)++;
}
return res;
}
/*--------------------------------------------------------------------------
* Read tail of comma separated size list ",i1,i2,...,in"
*
* Arguments:strptr pointer to string. It is assumed that the string has
* the format (","<size>)*
* maxl integer describing the maximal number of elements in the
list pointed to by strptr, max must be > 0.
* ilist array of dimension >= maxl of integers to be modified
*
* result: -EINVAL if the list is longer than maxl
* 0 otherwise
*
* side effects: for j=1,...,n ilist[ij] is set to the value of ij if it is
* a valid non-negative integer and to -EINVAL otherwise
* if no comma is found where it is expected an entry in
* ilist is set to -EINVAL
*-------------------------------------------------------------------------*/
static int
xpram_read_size_list_tail (char ** strptr, int maxl, int * ilist)
{
int i=0;
char *str = *strptr;
int res=0;
while ( (*str == ',') && (i < maxl) ) {
str++;
ilist[i] = xpram_read_size(&str);
if ( ilist[i] == -EINVAL ) {
xpram_scan_to_next_comma(&str);
res = -EINVAL;
}
i++;
}
return res;
#if 0 /* be lenient about trailing stuff */
if ( *str != 0 && *str != ' ' ) {
ilist[MAX(i-1,0)] = -EINVAL;
return -EINVAL;
} else return 0;
#endif
}
/*
* expanded memory operations
*/
/*--------------------------------------------------------------------*/
/* Copy expanded memory page (4kB) into main memory */
/* Arguments */
/* page_addr: address of target page */
/* xpage_index: index of expandeded memory page */
/* Return value */
/* 0: if operation succeeds */
/* non-0: otherwise */
/*--------------------------------------------------------------------*/
long xpram_page_in (unsigned long page_addr, unsigned long xpage_index)
{
int cc=0;
unsigned long real_page_addr = __pa(page_addr);
#ifndef CONFIG_ARCH_S390X
__asm__ __volatile__ (
" lr 1,%1 \n" /* r1 = real_page_addr */
" lr 2,%2 \n" /* r2 = xpage_index */
" .long 0xb22e0012 \n" /* pgin r1,r2 */
/* copy page from expanded memory */
"0: ipm %0 \n" /* save status (cc & program mask */
" srl %0,28 \n" /* cc into least significant bits */
"1: \n" /* we are done */
".section .fixup,\"ax\"\n" /* start of fix up section */
"2: lhi %0,2 \n" /* return unused condition code 2 */
" bras 1,3f \n" /* safe label 1: in r1 and goto 3 */
" .long 1b \n" /* literal containing label 1 */
"3: l 1,0(1) \n" /* load label 1 address into r1 */
" br 1 \n" /* goto label 1 (across sections) */
".previous \n" /* back in text section */
".section __ex_table,\"a\"\n" /* start __extable */
" .align 4 \n"
" .long 0b,2b \n" /* failure point 0, fixup code 2 */
".previous \n"
: "=d" (cc) : "d" (real_page_addr), "d" (xpage_index) : "cc", "1", "2"
);
#else /* CONFIG_ARCH_S390X */
__asm__ __volatile__ (
" lgr 1,%1 \n" /* r1 = real_page_addr */
" lgr 2,%2 \n" /* r2 = xpage_index */
" .long 0xb22e0012 \n" /* pgin r1,r2 */
/* copy page from expanded memory */
"0: ipm %0 \n" /* save status (cc & program mask */
" srl %0,28 \n" /* cc into least significant bits */
"1: \n" /* we are done */
".section .fixup,\"ax\"\n" /* start of fix up section */
"2: lghi %0,2 \n" /* return unused condition code 2 */
" jg 1b \n" /* goto label 1 above */
".previous \n" /* back in text section */
".section __ex_table,\"a\"\n" /* start __extable */
" .align 8 \n"
" .quad 0b,2b \n" /* failure point 0, fixup code 2 */
".previous \n"
: "=d" (cc) : "d" (real_page_addr), "d" (xpage_index) : "cc", "1", "2"
);
#endif /* CONFIG_ARCH_S390X */
switch (cc) {
case 0: return 0;
case 1: return -EIO;
case 2: return -ENXIO;
case 3: return -ENXIO;
default: return -EIO; /* should not happen */
};
}
/*--------------------------------------------------------------------*/
/* Copy a 4kB page of main memory to an expanded memory page */
/* Arguments */
/* page_addr: address of source page */
/* xpage_index: index of expandeded memory page */
/* Return value */
/* 0: if operation succeeds */
/* non-0: otherwise */
/*--------------------------------------------------------------------*/
long xpram_page_out (unsigned long page_addr, unsigned long xpage_index)
{
int cc=0;
unsigned long real_page_addr = __pa(page_addr);
#ifndef CONFIG_ARCH_S390X
__asm__ __volatile__ (
" lr 1,%1 \n" /* r1 = mem_page */
" lr 2,%2 \n" /* r2 = rpi */
" .long 0xb22f0012 \n" /* pgout r1,r2 */
/* copy page from expanded memory */
"0: ipm %0 \n" /* save status (cc & program mask */
" srl %0,28 \n" /* cc into least significant bits */
"1: \n" /* we are done */
".section .fixup,\"ax\"\n" /* start of fix up section */
"2: lhi %0,2 \n" /* return unused condition code 2 */
" bras 1,3f \n" /* safe label 1: in r1 and goto 3 */
" .long 1b \n" /* literal containing label 1 */
"3: l 1,0(1) \n" /* load label 1 address into r1 */
" br 1 \n" /* goto label 1 (across sections) */
".previous \n" /* back in text section */
".section __ex_table,\"a\"\n" /* start __extable */
" .align 4 \n"
" .long 0b,2b \n" /* failure point 0, fixup code 2 */
".previous \n"
: "=d" (cc) : "d" (real_page_addr), "d" (xpage_index) : "cc", "1", "2"
);
#else /* CONFIG_ARCH_S390X */
__asm__ __volatile__ (
" lgr 1,%1 \n" /* r1 = mem_page */
" lgr 2,%2 \n" /* r2 = rpi */
" .long 0xb22f0012 \n" /* pgout r1,r2 */
/* copy page from expanded memory */
"0: ipm %0 \n" /* save status (cc & program mask */
" srl %0,28 \n" /* cc into least significant bits */
"1: \n" /* we are done */
".section .fixup,\"ax\"\n" /* start of fix up section */
"2: lghi %0,2 \n" /* return unused condition code 2 */
" jg 1b \n" /* goto label 1 above */
".previous \n" /* back in text section */
".section __ex_table,\"a\"\n" /* start __extable */
" .align 8 \n"
" .quad 0b,2b \n" /* failure point 0, fixup code 2 */
".previous \n"
: "=d" (cc) : "d" (real_page_addr), "d" (xpage_index) : "cc", "1", "2"
);
#endif /* CONFIG_ARCH_S390X */
switch (cc) {
case 0: return 0;
case 1: return -EIO;
case 2: { PRINT_ERR("expanded storage lost!\n"); return -ENXIO; }
case 3: return -ENXIO;
default: return -EIO; /* should not happen */
}
}
/*--------------------------------------------------------------------*/
/* Measure expanded memory */
/* Return value */
/* size of expanded memory in kB (must be a multipe of 4) */
/*--------------------------------------------------------------------*/
int xpram_size(void)
{
int cc=0;
unsigned long base=0;
unsigned long po, pi, rpi; /* page index order, page index */
unsigned long mem_page = __get_free_page(GFP_KERNEL);
/* for po=0,1,2,... try to move in page number base+(2^po)-1 */
pi=1;
for (po=0; po <= 32; po++) { /* pi = 2^po */
cc=xpram_page_in(mem_page,base+pi-1);
if ( cc ) break;
pi <<= 1;
}
if ( cc && (po < 31 ) ) {
pi >>=1;
base += pi;
pi >>=1;
for ( ; pi > 0; pi >>= 1) {
rpi = pi - 1;
cc=xpram_page_in(mem_page,base+rpi);
if ( !cc ) base += pi;
}
}
free_page (mem_page);
if ( cc && (po < 31) )
return (XPRAM_KB_IN_PG * base);
else /* return maximal value possible */
return INT_MAX;
}
/*
* Open and close
*/
int xpram_open (struct inode *inode, struct file *filp)
{
Xpram_Dev *dev; /* device information */
int num = MINOR(inode->i_rdev);
if (num >= xpram_devs) return -ENODEV;
dev = xpram_devices + num;
PRINT_DEBUG("calling xpram_open for device %d\n",num);
PRINT_DEBUG(" size %dkB, name %s, usage: %d\n",
dev->size,dev->device_name, atomic_read(&(dev->usage)));
atomic_inc(&(dev->usage));
return 0; /* success */
}
int xpram_release (struct inode *inode, struct file *filp)
{
Xpram_Dev *dev = xpram_devices + MINOR(inode->i_rdev);
PRINT_DEBUG("calling xpram_release for device %d (size %dkB, usage: %d)\n",MINOR(inode->i_rdev) ,dev->size,atomic_read(&(dev->usage)));
/*
* If the device is closed for the last time, start a timer
* to release RAM in half a minute. The function and argument
* for the timer have been setup in init_module()
*/
if (!atomic_dec_return(&(dev->usage))) {
/* but flush it right now */
/* Everything is already flushed by caller -- AV */
}
return(0);
}
/*
* The ioctl() implementation
*/
int xpram_ioctl (struct inode *inode, struct file *filp,
unsigned int cmd, unsigned long arg)
{
int err, size;
struct hd_geometry *geo = (struct hd_geometry *)arg;
PRINT_DEBUG("ioctl 0x%x 0x%lx\n", cmd, arg);
switch(cmd) {
case BLKGETSIZE: /* 0x1260 */
/* Return the device size, expressed in sectors */
return put_user( 1024* xpram_sizes[MINOR(inode->i_rdev)]
/ XPRAM_SOFTSECT,
(unsigned long *) arg);
case BLKGETSIZE64:
return put_user( (u64)(1024* xpram_sizes[MINOR(inode->i_rdev)]
/ XPRAM_SOFTSECT) << 9,
(u64 *) arg);
case BLKFLSBUF: /* flush, 0x1261 */
fsync_dev(inode->i_rdev);
if ( capable(CAP_SYS_ADMIN) )invalidate_buffers(inode->i_rdev);
return 0;
case BLKRAGET: /* return the readahead value, 0x1263 */
if (!arg) return -EINVAL;
err = 0; /* verify_area_20(VERIFY_WRITE, (long *) arg, sizeof(long));
* if (err) return err;
*/
put_user(read_ahead[MAJOR(inode->i_rdev)], (long *)arg);
return 0;
case BLKRASET: /* set the readahead value, 0x1262 */
if (!capable(CAP_SYS_ADMIN)) return -EACCES;
if (arg > 0xff) return -EINVAL; /* limit it */
read_ahead[MAJOR(inode->i_rdev)] = arg;
atomic_eieio();
return 0;
case BLKRRPART: /* re-read partition table: can't do it, 0x1259 */
return -EINVAL;
#if (XPRAM_VERSION == 22)
RO_IOCTLS(inode->i_rdev, arg); /* the default RO operations
* BLKROSET
* BLKROGET
*/
#endif /* V22 */
case HDIO_GETGEO:
/*
* get geometry: we have to fake one... trim the size to a
* multiple of 64 (32k): tell we have 16 sectors, 4 heads,
* whatever cylinders. Tell also that data starts at sector. 4.
*/
size = xpram_mem_avail * 1024 / XPRAM_SOFTSECT;
/* size = xpram_mem_avail * 1024 / xpram_hardsect; */
size &= ~0x3f; /* multiple of 64 */
if (geo==NULL) return -EINVAL;
/*
* err=verify_area_20(VERIFY_WRITE, geo, sizeof(*geo));
* if (err) return err;
*/
put_user(size >> 6, &geo->cylinders);
put_user( 4, &geo->heads);
put_user( 16, &geo->sectors);
put_user( 4, &geo->start);
return 0;
}
return -EINVAL; /* unknown command */
}
/*
* The file operations
*/
#if (XPRAM_VERSION == 22)
struct file_operations xpram_fops = {
NULL, /* lseek: default */
block_read,
block_write,
NULL, /* xpram_readdir */
NULL, /* xpram_select */
xpram_ioctl,
NULL, /* xpram_mmap */
xpram_open,
NULL, /* flush */
xpram_release,
block_fsync,
NULL, /* xpram_fasync */
NULL,
NULL
};
#endif /* V22 */
#if (XPRAM_VERSION == 24)
struct block_device_operations xpram_devops =
{
owner: THIS_MODULE,
ioctl: xpram_ioctl,
open: xpram_open,
release: xpram_release,
};
#endif /* V24 */
/*
* Block-driver specific functions
*/
void xpram_request(request_queue_t * queue)
{
Xpram_Dev *device;
/* u8 *ptr; */
/* int size; */
unsigned long page_no; /* expanded memory page number */
unsigned long sects_to_copy; /* number of sectors to be copied */
char * buffer; /* local pointer into buffer cache */
int dev_no; /* device number of request */
int fault; /* faulty access to expanded memory */
#if ( XPRAM_VERSION == 24 )
struct request * current_req; /* working request */
#else
# define current_req CURRENT
#endif /* V24 */
while(1) {
INIT_REQUEST;
fault=0;
#if ( XPRAM_VERSION == 24 )
current_req = blkdev_entry_next_request (&queue->queue_head);
#endif /* V24 */
dev_no = DEVICE_NR(current_req->rq_dev);
/* Check if the minor number is in range */
if ( dev_no > xpram_devs ) {
static int count = 0;
if (count++ < 5) /* print the message at most five times */
PRINT_WARN(" request for unknown device\n");
end_request(0);
continue;
}
/* pointer to device structure, from the global array */
device = xpram_devices + dev_no;
sects_to_copy = current_req->current_nr_sectors;
/* does request exceed size of device ? */
if ( XPRAM_SEC2KB(sects_to_copy) > xpram_sizes[dev_no] ) {
PRINT_WARN(" request past end of device\n");
end_request(0);
continue;
}
/* Does request start at page boundery? -- paranoia */
#if 0
PRINT_DEBUG(" req %lx, sect %lx, to copy %lx, buf addr %lx\n", (unsigned long) current_req, current_req->sector, sects_to_copy, (unsigned long) current_req->buffer);
#endif
buffer = current_req->buffer;
#if XPRAM_SEC_IN_PG != 1
/* Does request start at an expanded storage page boundery? */
if ( current_req->sector & (XPRAM_SEC_IN_PG - 1) ) {
PRINT_WARN(" request does not start at an expanded storage page boundery\n");
PRINT_WARN(" referenced sector: %ld\n",current_req->sector);
end_request(0);
continue;
}
/* Does request refere to partial expanded storage pages? */
if ( sects_to_copy & (XPRAM_SEC_IN_PG - 1) ) {
PRINT_WARN(" request referes to a partial expanded storage page\n");
end_request(0);
continue;
}
#endif /* XPRAM_SEC_IN_PG != 1 */
/* Is request buffer aligned with kernel pages? */
if ( ((unsigned long)buffer) & (XPRAM_PGSIZE-1) ) {
PRINT_WARN(" request buffer is not aligned with kernel pages\n");
end_request(0);
continue;
}
/* which page of expanded storage is affected first? */
page_no = (xpram_offsets[dev_no] >> XPRAM_KB_IN_PG_ORDER)
+ (current_req->sector >> XPRAM_SEC_IN_PG_ORDER);
#if 0
PRINT_DEBUG("request: %d ( dev %d, copy %d sectors, at page %d ) \n", current_req->cmd,dev_no,sects_to_copy,page_no);
#endif
switch(current_req->cmd) {
case READ:
do {
if ( (fault=xpram_page_in((unsigned long)buffer,page_no)) ) {
PRINT_WARN("xpram(dev %d): page in failed for page %ld.\n",dev_no,page_no);
break;
}
sects_to_copy -= XPRAM_SEC_IN_PG;
buffer += XPRAM_PGSIZE;
page_no++;
} while ( sects_to_copy > 0 );
break;
case WRITE:
do {
if ( (fault=xpram_page_out((unsigned long)buffer,page_no))
) {
PRINT_WARN("xpram(dev %d): page out failed for page %ld.\n",dev_no,page_no);
break;
}
sects_to_copy -= XPRAM_SEC_IN_PG;
buffer += XPRAM_PGSIZE;
page_no++;
} while ( sects_to_copy > 0 );
break;
default:
/* can't happen */
end_request(0);
continue;
}
if ( fault ) end_request(0);
else end_request(1); /* success */
}
}
/*
* Kernel interfaces
*/
/*
* Parses the kernel parameters given in the kernel parameter line.
* The expected format is
* <number_of_partitions>[","<partition_size>]*
* where
* devices is a positive integer that initializes xpram_devs
* each size is a non-negative integer possibly followed by a
* magnitude (k,K,m,M,g,G), the list of sizes initialises
* xpram_sizes
*
* Arguments
* str: substring of kernel parameter line that contains xprams
* kernel parameters.
* ints: not used -- not in Version > 2.3 any more
*
* Result 0 on success, -EINVAl else -- only for Version > 2.3
*
* Side effects
* the global variabls devs is set to the value of
* <number_of_partitions> and sizes[i] is set to the i-th
* partition size (if provided). A parsing error of a value
* results in this value being set to -EINVAL.
*/
#if (XPRAM_VERSION == 22)
void xpram_setup (char *str, int *ints)
#else
int xpram_setup (char *str)
#endif /* V22 */
{
devs = xpram_read_int(&str);
if ( devs != -EINVAL )
if ( xpram_read_size_list_tail(&str,devs,sizes) < 0 ) {
PRINT_ERR("error while reading xpram parameters.\n");
#if (XPRAM_VERSION == 24)
return -EINVAL;
#endif /* V24 */
}
#if (XPRAM_VERSION == 24)
else return 0;
else return -EINVAL;
#elif (XPRAM_VERSION == 22)
return;
#endif /* V24/V22 */
}
/*
* initialize xpram device driver
*
* Result: 0 ok
* negative number: negative error code
*/
int xpram_init(void)
{
int result, i;
int mem_usable; /* net size of expanded memory */
int mem_needed=0; /* size of expanded memory needed to fullfill
* requirements of non-zero parameters in sizes
*/
int mem_auto_no=0; /* number of (implicit) zero parameters in sizes */
int mem_auto; /* automatically determined device size */
#if (XPRAM_VERSION == 24)
int minor_length; /* store the length of a minor (w/o '\0') */
int minor_thresh; /* threshhold for minor lenght */
request_queue_t *q; /* request queue */
#endif /* V24 */
/*
* Copy the (static) cfg variables to public prefixed ones to allow
* snoozing with a debugger.
*/
xpram_rahead = rahead;
xpram_blksize = blksize;
xpram_hardsect = hardsect;
PRINT_INFO("initializing: %s\n","");
/* check arguments */
xpram_major = major;
if ( (devs <= 0) || (devs > XPRAM_MAX_DEVS) ) {
PRINT_ERR("invalid number %d of devices\n",devs);
PRINT_ERR("Giving up xpram\n");
return -EINVAL;
}
xpram_devs = devs;
for (i=0; i < xpram_devs; i++) {
if ( sizes[i] < 0 ) {
PRINT_ERR("Invalid partition size %d kB\n",xpram_sizes[i]);
PRINT_ERR("Giving up xpram\n");
return -EINVAL;
} else {
xpram_sizes[i] = NEXT4(sizes[i]); /* page align */
if ( sizes[i] ) mem_needed += xpram_sizes[i];
else mem_auto_no++;
}
}
PRINT_DEBUG(" major %d \n", xpram_major);
PRINT_INFO(" number of devices (partitions): %d \n", xpram_devs);
for (i=0; i < xpram_devs; i++) {
if ( sizes[i] )
PRINT_INFO(" size of partition %d: %d kB\n", i, xpram_sizes[i]);
else
PRINT_INFO(" size of partition %d to be set automatically\n",i);
}
PRINT_DEBUG(" memory needed (for sized partitions): %d kB\n", mem_needed);
PRINT_DEBUG(" partitions to be sized automatically: %d\n", mem_auto_no);
#if 0
/* Hardsect can't be changed :( */
/* I try it any way. Yet I must distinguish
* between hardsects (to be changed to 4096)
* and soft sectors, hard-coded for buffer
* sizes within the requests
*/
if (hardsect != 512) {
PRINT_ERR("Can't change hardsect size\n");
hardsect = xpram_hardsect = 512;
}
#endif
PRINT_INFO(" hardsector size: %dB \n",xpram_hardsect);
/*
* Register your major, and accept a dynamic number
*/
#if (XPRAM_VERSION == 22)
result = register_blkdev(xpram_major, "xpram", &xpram_fops);
#elif (XPRAM_VERSION == 24)
result = devfs_register_blkdev(xpram_major, "xpram", &xpram_devops);
#endif /* V22/V24 */
if (result < 0) {
PRINT_ERR("Can't get major %d\n",xpram_major);
PRINT_ERR("Giving up xpram\n");
return result;
}
#if (XPRAM_VERSION == 24)
xpram_devfs_handle = devfs_mk_dir (NULL, "slram", NULL);
devfs_register_series (xpram_devfs_handle, "%u", XPRAM_MAX_DEVS,
DEVFS_FL_DEFAULT, XPRAM_MAJOR, 0,
S_IFBLK | S_IRUSR | S_IWUSR,
&xpram_devops, NULL);
#endif /* V22/V24 */
if (xpram_major == 0) xpram_major = result; /* dynamic */
major = xpram_major; /* Use `major' later on to save typing */
result = -ENOMEM; /* for the possible errors */
/*
* measure expanded memory
*/
xpram_mem_avail = xpram_size();
if (!xpram_mem_avail) {
PRINT_ERR("No or not enough expanded memory available\n");
PRINT_ERR("Giving up xpram\n");
result = -ENODEV;
goto fail_malloc;
}
PRINT_INFO(" %d kB expanded memory found.\n",xpram_mem_avail );
/*
* Assign the other needed values: request, rahead, size, blksize,
* hardsect. All the minor devices feature the same value.
* Note that `xpram' defines all of them to allow testing non-default
* values. A real device could well avoid setting values in global
* arrays if it uses the default values.
*/
#if (XPRAM_VERSION == 22)
blk_dev[major].request_fn = xpram_request;
#elif (XPRAM_VERSION == 24)
q = BLK_DEFAULT_QUEUE (major);
blk_init_queue (q, xpram_request);
blk_queue_headactive (BLK_DEFAULT_QUEUE (major), 0);
#endif /* V22/V24 */
read_ahead[major] = xpram_rahead;
/* we want to have XPRAM_UNUSED blocks security buffer between devices */
mem_usable=xpram_mem_avail-(XPRAM_UNUSED*(xpram_devs-1));
if ( mem_needed > mem_usable ) {
PRINT_ERR("Not enough expanded memory available\n");
PRINT_ERR("Giving up xpram\n");
goto fail_malloc;
}
/*
* partitioning:
* xpram_sizes[i] != 0; partition i has size xpram_sizes[i] kB
* else: ; all partitions i with xpram_sizesxpram_size[i]
* partition equally the remaining space
*/
if ( mem_auto_no ) {
mem_auto=LAST4((mem_usable-mem_needed)/mem_auto_no);
PRINT_INFO(" automatically determined partition size: %d kB\n", mem_auto);
for (i=0; i < xpram_devs; i++)
if (xpram_sizes[i] == 0) xpram_sizes[i] = mem_auto;
}
blk_size[major]=xpram_sizes;
xpram_offsets = kmalloc(xpram_devs * sizeof(int), GFP_KERNEL);
if (!xpram_offsets) {
PRINT_ERR("Not enough memory for xpram_offsets\n");
PRINT_ERR("Giving up xpram\n");
goto fail_malloc;
}
xpram_offsets[0] = 0;
for (i=1; i < xpram_devs; i++)
xpram_offsets[i] = xpram_offsets[i-1] + xpram_sizes[i-1] + XPRAM_UNUSED;
#if 0
for (i=0; i < xpram_devs; i++)
PRINT_DEBUG(" device(%d) offset = %d kB, size = %d kB\n",i, xpram_offsets[i], xpram_sizes[i]);
#endif
xpram_blksizes = kmalloc(xpram_devs * sizeof(int), GFP_KERNEL);
if (!xpram_blksizes) {
PRINT_ERR("Not enough memory for xpram_blksizes\n");
PRINT_ERR("Giving up xpram\n");
goto fail_malloc_blksizes;
}
for (i=0; i < xpram_devs; i++) /* all the same blocksize */
xpram_blksizes[i] = xpram_blksize;
blksize_size[major]=xpram_blksizes;
xpram_hardsects = kmalloc(xpram_devs * sizeof(int), GFP_KERNEL);
if (!xpram_hardsects) {
PRINT_ERR("Not enough memory for xpram_hardsects\n");
PRINT_ERR("Giving up xpram\n");
goto fail_malloc_hardsects;
}
for (i=0; i < xpram_devs; i++) /* all the same hardsect */
xpram_hardsects[i] = xpram_hardsect;
hardsect_size[major]=xpram_hardsects;
/*
* allocate the devices -- we can't have them static, as the number
* can be specified at load time
*/
xpram_devices = kmalloc(xpram_devs * sizeof (Xpram_Dev), GFP_KERNEL);
if (!xpram_devices) {
PRINT_ERR("Not enough memory for xpram_devices\n");
PRINT_ERR("Giving up xpram\n");
goto fail_malloc_devices;
}
memset(xpram_devices, 0, xpram_devs * sizeof (Xpram_Dev));
#if (XPRAM_VERSION == 24)
minor_length = 1;
minor_thresh = 10;
#endif /* V24 */
for (i=0; i < xpram_devs; i++) {
/* data and usage remain zeroed */
xpram_devices[i].size = xpram_sizes[i]; /* size in kB not in bytes */
atomic_set(&(xpram_devices[i].usage),0);
#if (XPRAM_VERSION == 24)
if (i == minor_thresh) {
minor_length++;
minor_thresh *= 10;
}
xpram_devices[i].device_name =
kmalloc(1 + strlen(XPRAM_DEVICE_NAME_PREFIX) + minor_length,GFP_KERNEL);
if ( xpram_devices[i].device_name == NULL ) {
PRINT_ERR("Not enough memory for xpram_devices[%d].device_name\n",i);
PRINT_ERR("Giving up xpram\n");
goto fail_devfs_register;
}
sprintf(xpram_devices[i].device_name,XPRAM_DEVICE_NAME_PREFIX "%d",i);
PRINT_DEBUG("initializing xpram_open for device %d\n",i);
PRINT_DEBUG(" size %dkB, name %s, usage: %d\n",
xpram_devices[i].size,xpram_devices[i].device_name, atomic_read(&(xpram_devices[i].usage)));
#if 0 /* WHY? */
xpram_devices[i].devfs_entry =
devfs_register(NULL /* devfs root dir */,
xpram_devices[i].device_name, 0,
0 /* flags */,
XPRAM_MAJOR,i,
0755 /* access mode */,
0 /* uid */, 0 /* gid */,
&xpram_devops,
(void *) &(xpram_devices[i])
);
if ( xpram_devices[i].devfs_entry == NULL ) {
PRINT_ERR("devfs system registry failed\n");
PRINT_ERR("Giving up xpram\n");
goto fail_devfs_register;
}
#endif /* WHY? */
#endif /* V24 */
}
return 0; /* succeed */
/* clean up memory in case of failures */
#if (XPRAM_VERSION == 24)
fail_devfs_register:
for (i=0; i < xpram_devs; i++) {
if ( xpram_devices[i].device_name )
kfree(xpram_devices[i].device_name);
}
kfree(xpram_devices);
#endif /* V24 */
fail_malloc_blksizes:
kfree (xpram_offsets);
fail_malloc_hardsects:
kfree (xpram_blksizes);
blksize_size[major] = NULL;
fail_malloc_devices:
kfree(xpram_hardsects);
hardsect_size[major] = NULL;
fail_malloc:
read_ahead[major] = 0;
#if (XPRAM_VERSION == 22)
blk_dev[major].request_fn = NULL;
#endif /* V22 */
/* ??? unregister_chrdev(major, "xpram"); */
unregister_blkdev(major, "xpram");
return result;
}
/*
* Finally, the module stuff
*/
int init_module(void)
{
int rc = 0;
PRINT_INFO ("trying to load module\n");
rc = xpram_init ();
if (rc == 0) {
PRINT_INFO ("Module loaded successfully\n");
} else {
PRINT_WARN ("Module load returned rc=%d\n", rc);
}
return rc;
}
void cleanup_module(void)
{
int i;
/* first of all, flush it all and reset all the data structures */
for (i=0; i<xpram_devs; i++)
fsync_dev(MKDEV(xpram_major, i)); /* flush the devices */
#if (XPRAM_VERSION == 22)
blk_dev[major].request_fn = NULL;
#endif /* V22 */
read_ahead[major] = 0;
blk_size[major] = NULL;
kfree(blksize_size[major]);
blksize_size[major] = NULL;
kfree(hardsect_size[major]);
hardsect_size[major] = NULL;
kfree(xpram_offsets);
/* finally, the usual cleanup */
#if (XPRAM_VERSION == 22)
unregister_blkdev(major, "xpram");
#elif (XPRAM_VERSION == 24)
devfs_unregister(xpram_devfs_handle);
if (devfs_unregister_blkdev(MAJOR_NR, "xpram"))
printk(KERN_WARNING "xpram: cannot unregister blkdev\n");
#endif /* V22/V24 */
kfree(xpram_devices);
}
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