cregit-Linux how code gets into the kernel

Release 4.7 drivers/sbus/char/flash.c

/* flash.c: Allow mmap access to the OBP Flash, for OBP updates.
 *
 * Copyright (C) 1997  Eddie C. Dost  (ecd@skynet.be)
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/of.h>
#include <linux/of_device.h>

#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/upa.h>

static DEFINE_MUTEX(flash_mutex);
static DEFINE_SPINLOCK(flash_lock);
static struct {
	
unsigned long read_base;	/* Physical read address */
	
unsigned long write_base;	/* Physical write address */
	
unsigned long read_size;	/* Size of read area */
	
unsigned long write_size;	/* Size of write area */
	
unsigned long busy;		/* In use? */
} 
flash;


#define FLASH_MINOR	152


static int flash_mmap(struct file *file, struct vm_area_struct *vma) { unsigned long addr; unsigned long size; spin_lock(&flash_lock); if (flash.read_base == flash.write_base) { addr = flash.read_base; size = flash.read_size; } else { if ((vma->vm_flags & VM_READ) && (vma->vm_flags & VM_WRITE)) { spin_unlock(&flash_lock); return -EINVAL; } if (vma->vm_flags & VM_READ) { addr = flash.read_base; size = flash.read_size; } else if (vma->vm_flags & VM_WRITE) { addr = flash.write_base; size = flash.write_size; } else { spin_unlock(&flash_lock); return -ENXIO; } } spin_unlock(&flash_lock); if ((vma->vm_pgoff << PAGE_SHIFT) > size) return -ENXIO; addr = vma->vm_pgoff + (addr >> PAGE_SHIFT); if (vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)) > size) size = vma->vm_end - (vma->vm_start + (vma->vm_pgoff << PAGE_SHIFT)); vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); if (io_remap_pfn_range(vma, vma->vm_start, addr, size, vma->vm_page_prot)) return -EAGAIN; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git22587.21%444.44%
linus torvaldslinus torvalds228.53%222.22%
william lee irwin iiiwilliam lee irwin iii51.94%111.11%
david s. millerdavid s. miller51.94%111.11%
randy dunlaprandy dunlap10.39%111.11%
Total258100.00%9100.00%


static long long flash_llseek(struct file *file, long long offset, int origin) { mutex_lock(&flash_mutex); switch (origin) { case 0: file->f_pos = offset; break; case 1: file->f_pos += offset; if (file->f_pos > flash.read_size) file->f_pos = flash.read_size; break; case 2: file->f_pos = flash.read_size; break; default: mutex_unlock(&flash_mutex); return -EINVAL; } mutex_unlock(&flash_mutex); return file->f_pos; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git8582.52%133.33%
arnd bergmannarnd bergmann1514.56%133.33%
robert loverobert love32.91%133.33%
Total103100.00%3100.00%


static ssize_t flash_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { loff_t p = *ppos; int i; if (count > flash.read_size - p) count = flash.read_size - p; for (i = 0; i < count; i++) { u8 data = upa_readb(flash.read_base + p + i); if (put_user(data, buf)) return -EFAULT; buf++; } *ppos += count; return count; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git6260.19%120.00%
linus torvaldslinus torvalds3433.01%120.00%
jan blunckjan blunck54.85%120.00%
david s. millerdavid s. miller10.97%120.00%
al viroal viro10.97%120.00%
Total103100.00%5100.00%


static int flash_open(struct inode *inode, struct file *file) { mutex_lock(&flash_mutex); if (test_and_set_bit(0, (void *)&flash.busy) != 0) { mutex_unlock(&flash_mutex); return -EBUSY; } mutex_unlock(&flash_mutex); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git4167.21%133.33%
arnd bergmannarnd bergmann2032.79%266.67%
Total61100.00%3100.00%


static int flash_release(struct inode *inode, struct file *file) { spin_lock(&flash_lock); flash.busy = 0; spin_unlock(&flash_lock); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git2772.97%266.67%
linus torvaldslinus torvalds1027.03%133.33%
Total37100.00%3100.00%

static const struct file_operations flash_fops = { /* no write to the Flash, use mmap * and play flash dependent tricks. */ .owner = THIS_MODULE, .llseek = flash_llseek, .read = flash_read, .mmap = flash_mmap, .open = flash_open, .release = flash_release, }; static struct miscdevice flash_dev = { FLASH_MINOR, "flash", &flash_fops };
static int flash_probe(struct platform_device *op) { struct device_node *dp = op->dev.of_node; struct device_node *parent; parent = dp->parent; if (strcmp(parent->name, "sbus") && strcmp(parent->name, "sbi") && strcmp(parent->name, "ebus")) return -ENODEV; flash.read_base = op->resource[0].start; flash.read_size = resource_size(&op->resource[0]); if (op->resource[1].flags) { flash.write_base = op->resource[1].start; flash.write_size = resource_size(&op->resource[1]); } else { flash.write_base = op->resource[0].start; flash.write_size = resource_size(&op->resource[0]); } flash.busy = 0; printk(KERN_INFO "%s: OBP Flash, RD %lx[%lx] WR %lx[%lx]\n", op->dev.of_node->full_name, flash.read_base, flash.read_size, flash.write_base, flash.write_size); return misc_register(&flash_dev); }

Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git12760.77%444.44%
david s. millerdavid s. miller7535.89%333.33%
grant likelygrant likely73.35%222.22%
Total209100.00%9100.00%


static int flash_remove(struct platform_device *op) { misc_deregister(&flash_dev); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
david s. millerdavid s. miller1260.00%133.33%
pre-gitpre-git735.00%133.33%
grant likelygrant likely15.00%133.33%
Total20100.00%3100.00%

static const struct of_device_id flash_match[] = { { .name = "flashprom", }, {}, }; MODULE_DEVICE_TABLE(of, flash_match); static struct platform_driver flash_driver = { .driver = { .name = "flash", .of_match_table = flash_match, }, .probe = flash_probe, .remove = flash_remove, }; module_platform_driver(flash_driver); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
pre-gitpre-git68267.93%1027.78%
david s. millerdavid s. miller15215.14%616.67%
linus torvaldslinus torvalds767.57%411.11%
arnd bergmannarnd bergmann424.18%25.56%
grant likelygrant likely151.49%411.11%
rusty russellrusty russell121.20%12.78%
william lee irwin iiiwilliam lee irwin iii50.50%12.78%
jan blunckjan blunck50.50%12.78%
thomas gleixnerthomas gleixner40.40%12.78%
robert loverobert love30.30%12.78%
horst h. von brandhorst h. von brand30.30%12.78%
axel linaxel lin20.20%12.78%
al viroal viro10.10%12.78%
arjan van de venarjan van de ven10.10%12.78%
randy dunlaprandy dunlap10.10%12.78%
Total1004100.00%36100.00%
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