cregit-Linux how code gets into the kernel

Release 4.7 drivers/sbus/char/jsflash.c

/*
 * drivers/sbus/char/jsflash.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds    (drivers/char/mem.c)
 *  Copyright (C) 1997  Eddie C. Dost           (drivers/sbus/char/flash.c)
 *  Copyright (C) 1997-2000 Pavel Machek <pavel@ucw.cz>   (drivers/block/nbd.c)
 *  Copyright (C) 1999-2000 Pete Zaitcev
 *
 * This driver is used to program OS into a Flash SIMM on
 * Krups and Espresso platforms.
 *
 * TODO: do not allow erase/programming if file systems are mounted.
 * TODO: Erase/program both banks of a 8MB SIMM.
 *
 * It is anticipated that programming an OS Flash will be a routine
 * procedure. In the same time it is exceedingly dangerous because
 * a user can program its OBP flash with OS image and effectively
 * kill the machine.
 *
 * This driver uses an interface different from Eddie's flash.c
 * as a silly safeguard.
 *
 * XXX The flash.c manipulates page caching characteristics in a certain
 * dubious way; also it assumes that remap_pfn_range() can remap
 * PCI bus locations, which may be false. ioremap() must be used
 * instead. We should discuss this.
 */

#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/genhd.h>
#include <linux/blkdev.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/pcic.h>
#include <asm/oplib.h>

#include <asm/jsflash.h>		/* ioctl arguments. <linux/> ?? */

#define JSFIDSZ		(sizeof(struct jsflash_ident_arg))

#define JSFPRGSZ	(sizeof(struct jsflash_program_arg))

/*
 * Our device numbers have no business in system headers.
 * The only thing a user knows is the device name /dev/jsflash.
 *
 * Block devices are laid out like this:
 *   minor+0    - Bootstrap, for 8MB SIMM 0x20400000[0x800000]
 *   minor+1    - Filesystem to mount, normally 0x20400400[0x7ffc00]
 *   minor+2    - Whole flash area for any case... 0x20000000[0x01000000]
 * Total 3 minors per flash device.
 *
 * It is easier to have static size vectors, so we define
 * a total minor range JSF_MAX, which must cover all minors.
 */
/* character device */

#define JSF_MINOR	178	
/* 178 is registered with hpa */
/* block device */

#define JSF_MAX		 3	
/* 3 minors wasted total so far. */

#define JSF_NPART	 3	
/* 3 minors per flash device */

#define JSF_PART_BITS	 2	
/* 2 bits of minors to cover JSF_NPART */

#define JSF_PART_MASK	 0x3	
/* 2 bits mask */

static DEFINE_MUTEX(jsf_mutex);

/*
 * Access functions.
 * We could ioremap(), but it's easier this way.
 */

static unsigned int jsf_inl(unsigned long addr) { unsigned long retval; __asm__ __volatile__("lda [%1] %2, %0\n\t" : "=r" (retval) : "r" (addr), "i" (ASI_M_BYPASS)); return retval; }

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static void jsf_outl(unsigned long addr, __u32 data) { __asm__ __volatile__("sta %0, [%1] %2\n\t" : : "r" (data), "r" (addr), "i" (ASI_M_BYPASS) : "memory"); }

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/* * soft carrier */ struct jsfd_part { unsigned long dbase; unsigned long dsize; }; struct jsflash { unsigned long base; unsigned long size; unsigned long busy; /* In use? */ struct jsflash_ident_arg id; /* int mbase; */ /* Minor base, typically zero */ struct jsfd_part dv[JSF_NPART]; }; /* * We do not map normal memory or obio as a safety precaution. * But offsets are real, for ease of userland programming. */ #define JSF_BASE_TOP 0x30000000 #define JSF_BASE_ALL 0x20000000 #define JSF_BASE_JK 0x20400000 /* */ static struct gendisk *jsfd_disk[JSF_MAX]; /* * Let's pretend we may have several of these... */ static struct jsflash jsf0; /* * Wait for AMD to finish its embedded algorithm. * We use the Toggle bit DQ6 (0x40) because it does not * depend on the data value as /DATA bit DQ7 does. * * XXX Do we need any timeout here? So far it never hanged, beware broken hw. */
static void jsf_wait(unsigned long p) { unsigned int x1, x2; for (;;) { x1 = jsf_inl(p); x2 = jsf_inl(p); if ((x1 & 0x40404040) == (x2 & 0x40404040)) return; } }

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/* * Programming will only work if Flash is clean, * we leave it to the programmer application. * * AMD must be programmed one byte at a time; * thus, Simple Tech SIMM must be written 4 bytes at a time. * * Write waits for the chip to become ready after the write * was finished. This is done so that application would read * consistent data after the write is done. */
static void jsf_write4(unsigned long fa, u32 data) { jsf_outl(fa, 0xAAAAAAAA); /* Unlock 1 Write 1 */ jsf_outl(fa, 0x55555555); /* Unlock 1 Write 2 */ jsf_outl(fa, 0xA0A0A0A0); /* Byte Program */ jsf_outl(fa, data); jsf_wait(fa); }

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/* */
static void jsfd_read(char *buf, unsigned long p, size_t togo) { union byte4 { char s[4]; unsigned int n; } b; while (togo >= 4) { togo -= 4; b.n = jsf_inl(p); memcpy(buf, b.s, 4); p += 4; buf += 4; } }

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static void jsfd_do_request(struct request_queue *q) { struct request *req; req = blk_fetch_request(q); while (req) { struct jsfd_part *jdp = req->rq_disk->private_data; unsigned long offset = blk_rq_pos(req) << 9; size_t len = blk_rq_cur_bytes(req); int err = -EIO; if ((offset + len) > jdp->dsize) goto end; if (rq_data_dir(req) != READ) { printk(KERN_ERR "jsfd: write\n"); goto end; } if ((jdp->dbase & 0xff000000) != 0x20000000) { printk(KERN_ERR "jsfd: bad base %x\n", (int)jdp->dbase); goto end; } jsfd_read(bio_data(req->bio), jdp->dbase + offset, len); err = 0; end: if (!__blk_end_request_cur(req, err)) req = blk_fetch_request(q); } }

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tejun heotejun heo4425.73%541.67%
al viroal viro179.94%216.67%
jens axboejens axboe116.43%325.00%
pete zaitcevpete zaitcev21.17%18.33%
Total171100.00%12100.00%

/* * The memory devices use the full 32/64 bits of the offset, and so we cannot * check against negative addresses: they are ok. The return value is weird, * though, in that case (0). * * also note that seeking relative to the "end of file" isn't supported: * it has no meaning, so it returns -EINVAL. */
static loff_t jsf_lseek(struct file * file, loff_t offset, int orig) { loff_t ret; mutex_lock(&jsf_mutex); switch (orig) { case 0: file->f_pos = offset; ret = file->f_pos; break; case 1: file->f_pos += offset; ret = file->f_pos; break; default: ret = -EINVAL; } mutex_unlock(&jsf_mutex); return ret; }

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robert loverobert love1924.05%133.33%
arnd bergmannarnd bergmann1012.66%133.33%
Total79100.00%3100.00%

/* * OS SIMM Cannot be read in other size but a 32bits word. */
static ssize_t jsf_read(struct file * file, char __user * buf, size_t togo, loff_t *ppos) { unsigned long p = *ppos; char __user *tmp = buf; union byte4 { char s[4]; unsigned int n; } b; if (p < JSF_BASE_ALL || p >= JSF_BASE_TOP) { return 0; } if ((p + togo) < p /* wrap */ || (p + togo) >= JSF_BASE_TOP) { togo = JSF_BASE_TOP - p; } if (p < JSF_BASE_ALL && togo != 0) { #if 0 /* __bzero XXX */ size_t x = JSF_BASE_ALL - p; if (x > togo) x = togo; clear_user(tmp, x); tmp += x; p += x; togo -= x; #else /* * Implementation of clear_user() calls __bzero * without regard to modversions, * so we cannot build a module. */ return 0; #endif } while (togo >= 4) { togo -= 4; b.n = jsf_inl(p); if (copy_to_user(tmp, b.s, 4)) return -EFAULT; tmp += 4; p += 4; } /* * XXX Small togo may remain if 1 byte is ordered. * It would be nice if we did a word size read and unpacked it. */ *ppos = p; return tmp-buf; }

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pre-gitpre-git16894.92%360.00%
pete zaitcevpete zaitcev73.95%120.00%
al viroal viro21.13%120.00%
Total177100.00%5100.00%


static ssize_t jsf_write(struct file * file, const char __user * buf, size_t count, loff_t *ppos) { return -ENOSPC; }

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/* */
static int jsf_ioctl_erase(unsigned long arg) { unsigned long p; /* p = jsf0.base; hits wrong bank */ p = 0x20400000; jsf_outl(p, 0xAAAAAAAA); /* Unlock 1 Write 1 */ jsf_outl(p, 0x55555555); /* Unlock 1 Write 2 */ jsf_outl(p, 0x80808080); /* Erase setup */ jsf_outl(p, 0xAAAAAAAA); /* Unlock 2 Write 1 */ jsf_outl(p, 0x55555555); /* Unlock 2 Write 2 */ jsf_outl(p, 0x10101010); /* Chip erase */ #if 0 /* * This code is ok, except that counter based timeout * has no place in this world. Let's just drop timeouts... */ { int i; __u32 x; for (i = 0; i < 1000000; i++) { x = jsf_inl(p); if ((x & 0x80808080) == 0x80808080) break; } if ((x & 0x80808080) != 0x80808080) { printk("jsf0: erase timeout with 0x%08x\n", x); } else { printk("jsf0: erase done with 0x%08x\n", x); } } #else jsf_wait(p); #endif return 0; }

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/* * Program a block of flash. * Very simple because we can do it byte by byte anyway. */
static int jsf_ioctl_program(void __user *arg) { struct jsflash_program_arg abuf; char __user *uptr; unsigned long p; unsigned int togo; union { unsigned int n; char s[4]; } b; if (copy_from_user(&abuf, arg, JSFPRGSZ)) return -EFAULT; p = abuf.off; togo = abuf.size; if ((togo & 3) || (p & 3)) return -EINVAL; uptr = (char __user *) (unsigned long) abuf.data; while (togo != 0) { togo -= 4; if (copy_from_user(&b.s[0], uptr, 4)) return -EFAULT; jsf_write4(p, b.n); p += 4; uptr += 4; } return 0; }

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pre-gitpre-git14290.45%360.00%
pete zaitcevpete zaitcev106.37%120.00%
al viroal viro53.18%120.00%
Total157100.00%5100.00%


static long jsf_ioctl(struct file *f, unsigned int cmd, unsigned long arg) { mutex_lock(&jsf_mutex); int error = -ENOTTY; void __user *argp = (void __user *)arg; if (!capable(CAP_SYS_ADMIN)) { mutex_unlock(&jsf_mutex); return -EPERM; } switch (cmd) { case JSFLASH_IDENT: if (copy_to_user(argp, &jsf0.id, JSFIDSZ)) { mutex_unlock(&jsf_mutex); return -EFAULT; } break; case JSFLASH_ERASE: error = jsf_ioctl_erase(arg); break; case JSFLASH_PROGRAM: error = jsf_ioctl_program(argp); break; } mutex_unlock(&jsf_mutex); return error; }

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pre-gitpre-git8162.31%233.33%
arnd bergmannarnd bergmann2015.38%116.67%
al viroal viro1410.77%116.67%
stoyan gaydarovstoyan gaydarov96.92%116.67%
pete zaitcevpete zaitcev64.62%116.67%
Total130100.00%6100.00%


static int jsf_mmap(struct file * file, struct vm_area_struct * vma) { return -ENXIO; }

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static int jsf_open(struct inode * inode, struct file * filp) { mutex_lock(&jsf_mutex); if (jsf0.base == 0) { mutex_unlock(&jsf_mutex); return -ENXIO; } if (test_and_set_bit(0, (void *)&jsf0.busy) != 0) { mutex_unlock(&jsf_mutex); return -EBUSY; } mutex_unlock(&jsf_mutex); return 0; /* XXX What security? */ }

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arnd bergmannarnd bergmann2834.15%250.00%
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static int jsf_release(struct inode *inode, struct file *file) { jsf0.busy = 0; return 0; }

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static const struct file_operations jsf_fops = { .owner = THIS_MODULE, .llseek = jsf_lseek, .read = jsf_read, .write = jsf_write, .unlocked_ioctl = jsf_ioctl, .mmap = jsf_mmap, .open = jsf_open, .release = jsf_release, }; static struct miscdevice jsf_dev = { JSF_MINOR, "jsflash", &jsf_fops }; static const struct block_device_operations jsfd_fops = { .owner = THIS_MODULE, };
static int jsflash_init(void) { int rc; struct jsflash *jsf; phandle node; char banner[128]; struct linux_prom_registers reg0; node = prom_getchild(prom_root_node); node = prom_searchsiblings(node, "flash-memory"); if (node != 0 && (s32)node != -1) { if (prom_getproperty(node, "reg", (char *)&reg0, sizeof(reg0)) == -1) { printk("jsflash: no \"reg\" property\n"); return -ENXIO; } if (reg0.which_io != 0) { printk("jsflash: bus number nonzero: 0x%x:%x\n", reg0.which_io, reg0.phys_addr); return -ENXIO; } /* * Flash may be somewhere else, for instance on Ebus. * So, don't do the following check for IIep flash space. */ #if 0 if ((reg0.phys_addr >> 24) != 0x20) { printk("jsflash: suspicious address: 0x%x:%x\n", reg0.which_io, reg0.phys_addr); return -ENXIO; } #endif if ((int)reg0.reg_size <= 0) { printk("jsflash: bad size 0x%x\n", (int)reg0.reg_size); return -ENXIO; } } else { /* XXX Remove this code once PROLL ID12 got widespread */ printk("jsflash: no /flash-memory node, use PROLL >= 12\n"); prom_getproperty(prom_root_node, "banner-name", banner, 128); if (strcmp (banner, "JavaStation-NC") != 0 && strcmp (banner, "JavaStation-E") != 0) { return -ENXIO; } reg0.which_io = 0; reg0.phys_addr = 0x20400000; reg0.reg_size = 0x00800000; } /* Let us be really paranoid for modifications to probing code. */ if (sparc_cpu_model != sun4m) { /* We must be on sun4m because we use MMU Bypass ASI. */ return -ENXIO; } if (jsf0.base == 0) { jsf = &jsf0; jsf->base = reg0.phys_addr; jsf->size = reg0.reg_size; /* XXX Redo the userland interface. */ jsf->id.off = JSF_BASE_ALL; jsf->id.size = 0x01000000; /* 16M - all segments */ strcpy(jsf->id.name, "Krups_all"); jsf->dv[0].dbase = jsf->base; jsf->dv[0].dsize = jsf->size; jsf->dv[1].dbase = jsf->base + 1024; jsf->dv[1].dsize = jsf->size - 1024; jsf->dv[2].dbase = JSF_BASE_ALL; jsf->dv[2].dsize = 0x01000000; printk("Espresso Flash @0x%lx [%d MB]\n", jsf->base, (int) (jsf->size / (1024*1024))); } if ((rc = misc_register(&jsf_dev)) != 0) { printk(KERN_ERR "jsf: unable to get misc minor %d\n", JSF_MINOR); jsf0.base = 0; return rc; } return 0; }

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static struct request_queue *jsf_queue;
static int jsfd_init(void) { static DEFINE_SPINLOCK(lock); struct jsflash *jsf; struct jsfd_part *jdp; int err; int i; if (jsf0.base == 0) return -ENXIO; err = -ENOMEM; for (i = 0; i < JSF_MAX; i++) { struct gendisk *disk = alloc_disk(1); if (!disk) goto out; jsfd_disk[i] = disk; } if (register_blkdev(JSFD_MAJOR, "jsfd")) { err = -EIO; goto out; } jsf_queue = blk_init_queue(jsfd_do_request, &lock); if (!jsf_queue) { err = -ENOMEM; unregister_blkdev(JSFD_MAJOR, "jsfd"); goto out; } for (i = 0; i < JSF_MAX; i++) { struct gendisk *disk = jsfd_disk[i]; if ((i & JSF_PART_MASK) >= JSF_NPART) continue; jsf = &jsf0; /* actually, &jsfv[i >> JSF_PART_BITS] */ jdp = &jsf->dv[i&JSF_PART_MASK]; disk->major = JSFD_MAJOR; disk->first_minor = i; sprintf(disk->disk_name, "jsfd%d", i); disk->fops = &jsfd_fops; set_capacity(disk, jdp->dsize >> 9); disk->private_data = jdp; disk->queue = jsf_queue; add_disk(disk); set_disk_ro(disk, 1); } return 0; out: while (i--) put_disk(jsfd_disk[i]); return err; }

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thomas gleixnerthomas gleixner41.44%19.09%
Total278100.00%11100.00%

MODULE_LICENSE("GPL");
static int __init jsflash_init_module(void) { int rc; if ((rc = jsflash_init()) == 0) { jsfd_init(); return 0; } return rc; }

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static void __exit jsflash_cleanup_module(void) { int i; for (i = 0; i < JSF_MAX; i++) { if ((i & JSF_PART_MASK) >= JSF_NPART) continue; del_gendisk(jsfd_disk[i]); put_disk(jsfd_disk[i]); } if (jsf0.busy) printk("jsf0: cleaning busy unit\n"); jsf0.base = 0; jsf0.busy = 0; misc_deregister(&jsf_dev); unregister_blkdev(JSFD_MAJOR, "jsfd"); blk_cleanup_queue(jsf_queue); }

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al viroal viro4648.42%342.86%
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pete zaitcevpete zaitcev33.16%114.29%
Total95100.00%7100.00%

module_init(jsflash_init_module); module_exit(jsflash_cleanup_module);

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arnd bergmannarnd bergmann672.94%24.55%
pete zaitcevpete zaitcev441.93%24.55%
tejun heotejun heo441.93%511.36%
jens axboejens axboe361.58%49.09%
robert loverobert love190.83%12.27%
rusty russellrusty russell180.79%12.27%
stoyan gaydarovstoyan gaydarov100.44%12.27%
linus torvaldslinus torvalds70.31%24.55%
andres salomonandres salomon40.18%24.55%
thomas gleixnerthomas gleixner40.18%12.27%
alexey dobriyanalexey dobriyan10.04%12.27%
lucas de marchilucas de marchi10.04%12.27%
arjan van de venarjan van de ven10.04%12.27%
Total2279100.00%44100.00%
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