*
* Added devfs support.
* Jan-11-1998, C. Scott Ananian <cananian@alumni.princeton.edu>
- * Shared /dev/zero mmaping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com>
+ * Shared /dev/zero mmapping support, Feb 2000, Kanoj Sarcar <kanoj@sgi.com>
*/
#include <linux/mm.h>
#include <linux/bootmem.h>
#include <linux/splice.h>
#include <linux/pfn.h>
-#include <linux/smp_lock.h>
#include <asm/uaccess.h>
#include <asm/io.h>
# include <linux/efi.h>
#endif
+static inline unsigned long size_inside_page(unsigned long start,
+ unsigned long size)
+{
+ unsigned long sz;
+
+ sz = PAGE_SIZE - (start & (PAGE_SIZE - 1));
+
+ return min(sz, size);
+}
+
/*
* Architectures vary in how they handle caching for addresses
* outside of main memory.
{
#if defined(CONFIG_IA64)
/*
- * On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases.
+ * On ia64, we ignore O_DSYNC because we cannot tolerate memory attribute aliases.
*/
return !(efi_mem_attributes(addr) & EFI_MEMORY_WB);
#elif defined(CONFIG_MIPS)
#else
/*
* Accessing memory above the top the kernel knows about or through a file pointer
- * that was marked O_SYNC will be done non-cached.
+ * that was marked O_DSYNC will be done non-cached.
*/
- if (file->f_flags & O_SYNC)
+ if (file->f_flags & O_DSYNC)
return 1;
return addr >= __pa(high_memory);
#endif
#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
/* we don't have page 0 mapped on sparc and m68k.. */
if (p < PAGE_SIZE) {
- sz = PAGE_SIZE - p;
- if (sz > count)
- sz = count;
+ sz = size_inside_page(p, count);
if (sz > 0) {
if (clear_user(buf, sz))
return -EFAULT;
#endif
while (count > 0) {
- /*
- * Handle first page in case it's not aligned
- */
- if (-p & (PAGE_SIZE - 1))
- sz = -p & (PAGE_SIZE - 1);
- else
- sz = PAGE_SIZE;
+ unsigned long remaining;
- sz = min_t(unsigned long, sz, count);
+ sz = size_inside_page(p, count);
if (!range_is_allowed(p >> PAGE_SHIFT, count))
return -EPERM;
if (!ptr)
return -EFAULT;
- if (copy_to_user(buf, ptr, sz)) {
- unxlate_dev_mem_ptr(p, ptr);
- return -EFAULT;
- }
-
+ remaining = copy_to_user(buf, ptr, sz);
unxlate_dev_mem_ptr(p, ptr);
+ if (remaining)
+ return -EFAULT;
buf += sz;
p += sz;
#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
/* we don't have page 0 mapped on sparc and m68k.. */
if (p < PAGE_SIZE) {
- unsigned long sz = PAGE_SIZE - p;
- if (sz > count)
- sz = count;
+ sz = size_inside_page(p, count);
/* Hmm. Do something? */
buf += sz;
p += sz;
#endif
while (count > 0) {
- /*
- * Handle first page in case it's not aligned
- */
- if (-p & (PAGE_SIZE - 1))
- sz = -p & (PAGE_SIZE - 1);
- else
- sz = PAGE_SIZE;
-
- sz = min_t(unsigned long, sz, count);
+ sz = size_inside_page(p, count);
if (!range_is_allowed(p >> PAGE_SHIFT, sz))
return -EPERM;
}
copied = copy_from_user(ptr, buf, sz);
+ unxlate_dev_mem_ptr(p, ptr);
if (copied) {
written += sz - copied;
- unxlate_dev_mem_ptr(p, ptr);
if (written)
break;
return -EFAULT;
}
- unxlate_dev_mem_ptr(p, ptr);
-
buf += sz;
p += sz;
count -= sz;
}
#endif
-void __attribute__((weak))
-map_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
-{
- /* nothing. architectures can override. */
-}
-
-void __attribute__((weak))
-unmap_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
-{
- /* nothing. architectures can override. */
-}
-
-static void mmap_mem_open(struct vm_area_struct *vma)
-{
- map_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
- vma->vm_page_prot);
-}
-
-static void mmap_mem_close(struct vm_area_struct *vma)
-{
- unmap_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
- vma->vm_page_prot);
-}
-
-static struct vm_operations_struct mmap_mem_ops = {
- .open = mmap_mem_open,
- .close = mmap_mem_close,
+static const struct vm_operations_struct mmap_mem_ops = {
#ifdef CONFIG_HAVE_IOREMAP_PROT
.access = generic_access_phys
#endif
vma->vm_pgoff,
size,
vma->vm_page_prot)) {
- unmap_devmem(vma->vm_pgoff, size, vma->vm_page_prot);
return -EAGAIN;
}
return 0;
}
#endif
-extern long vread(char *buf, char *addr, unsigned long count);
-extern long vwrite(char *buf, char *addr, unsigned long count);
-
#ifdef CONFIG_DEVKMEM
/*
* This function reads the *virtual* memory as seen by the kernel.
#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
/* we don't have page 0 mapped on sparc and m68k.. */
if (p < PAGE_SIZE && low_count > 0) {
- size_t tmp = PAGE_SIZE - p;
- if (tmp > low_count) tmp = low_count;
- if (clear_user(buf, tmp))
+ sz = size_inside_page(p, low_count);
+ if (clear_user(buf, sz))
return -EFAULT;
- buf += tmp;
- p += tmp;
- read += tmp;
- low_count -= tmp;
- count -= tmp;
+ buf += sz;
+ p += sz;
+ read += sz;
+ low_count -= sz;
+ count -= sz;
}
#endif
while (low_count > 0) {
- /*
- * Handle first page in case it's not aligned
- */
- if (-p & (PAGE_SIZE - 1))
- sz = -p & (PAGE_SIZE - 1);
- else
- sz = PAGE_SIZE;
-
- sz = min_t(unsigned long, sz, low_count);
+ sz = size_inside_page(p, low_count);
/*
* On ia64 if a page has been mapped somewhere as
if (!kbuf)
return -ENOMEM;
while (count > 0) {
- int len = count;
-
- if (len > PAGE_SIZE)
- len = PAGE_SIZE;
- len = vread(kbuf, (char *)p, len);
- if (!len)
+ sz = size_inside_page(p, count);
+ sz = vread(kbuf, (char *)p, sz);
+ if (!sz)
break;
- if (copy_to_user(buf, kbuf, len)) {
+ if (copy_to_user(buf, kbuf, sz)) {
free_page((unsigned long)kbuf);
return -EFAULT;
}
- count -= len;
- buf += len;
- read += len;
- p += len;
+ count -= sz;
+ buf += sz;
+ read += sz;
+ p += sz;
}
free_page((unsigned long)kbuf);
}
static inline ssize_t
-do_write_kmem(void *p, unsigned long realp, const char __user * buf,
+do_write_kmem(unsigned long p, const char __user *buf,
size_t count, loff_t *ppos)
{
ssize_t written, sz;
written = 0;
#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
/* we don't have page 0 mapped on sparc and m68k.. */
- if (realp < PAGE_SIZE) {
- unsigned long sz = PAGE_SIZE - realp;
- if (sz > count)
- sz = count;
+ if (p < PAGE_SIZE) {
+ sz = size_inside_page(p, count);
/* Hmm. Do something? */
buf += sz;
p += sz;
- realp += sz;
count -= sz;
written += sz;
}
while (count > 0) {
char *ptr;
- /*
- * Handle first page in case it's not aligned
- */
- if (-realp & (PAGE_SIZE - 1))
- sz = -realp & (PAGE_SIZE - 1);
- else
- sz = PAGE_SIZE;
- sz = min_t(unsigned long, sz, count);
+ sz = size_inside_page(p, count);
/*
* On ia64 if a page has been mapped somewhere as
* uncached, then it must also be accessed uncached
* by the kernel or data corruption may occur
*/
- ptr = xlate_dev_kmem_ptr(p);
+ ptr = xlate_dev_kmem_ptr((char *)p);
copied = copy_from_user(ptr, buf, sz);
if (copied) {
}
buf += sz;
p += sz;
- realp += sz;
count -= sz;
written += sz;
}
unsigned long p = *ppos;
ssize_t wrote = 0;
ssize_t virtr = 0;
- ssize_t written;
char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */
if (p < (unsigned long) high_memory) {
-
- wrote = count;
- if (count > (unsigned long) high_memory - p)
- wrote = (unsigned long) high_memory - p;
-
- written = do_write_kmem((void*)p, p, buf, wrote, ppos);
- if (written != wrote)
- return written;
- wrote = written;
+ unsigned long to_write = min_t(unsigned long, count,
+ (unsigned long)high_memory - p);
+ wrote = do_write_kmem(p, buf, to_write, ppos);
+ if (wrote != to_write)
+ return wrote;
p += wrote;
buf += wrote;
count -= wrote;
if (!kbuf)
return wrote ? wrote : -ENOMEM;
while (count > 0) {
- int len = count;
-
- if (len > PAGE_SIZE)
- len = PAGE_SIZE;
- if (len) {
- written = copy_from_user(kbuf, buf, len);
- if (written) {
- if (wrote + virtr)
- break;
- free_page((unsigned long)kbuf);
- return -EFAULT;
- }
+ unsigned long sz = size_inside_page(p, count);
+ unsigned long n;
+
+ n = copy_from_user(kbuf, buf, sz);
+ if (n) {
+ if (wrote + virtr)
+ break;
+ free_page((unsigned long)kbuf);
+ return -EFAULT;
}
- len = vwrite(kbuf, (char *)p, len);
- count -= len;
- buf += len;
- virtr += len;
- p += len;
+ sz = vwrite(kbuf, (char *)p, sz);
+ count -= sz;
+ buf += sz;
+ virtr += sz;
+ p += sz;
}
free_page((unsigned long)kbuf);
}
if (chunk > PAGE_SIZE)
chunk = PAGE_SIZE; /* Just for latency reasons */
- unwritten = clear_user(buf, chunk);
+ unwritten = __clear_user(buf, chunk);
written += chunk - unwritten;
if (unwritten)
break;
+ if (signal_pending(current))
+ return written ? written : -ERESTARTSYS;
buf += chunk;
count -= chunk;
cond_resched();
* - permits private mappings, "copies" are taken of the source of zeros
*/
static struct backing_dev_info zero_bdi = {
+ .name = "char/mem",
.capabilities = BDI_CAP_MAP_COPY,
};
.write = kmsg_write,
};
-static int memory_open(struct inode * inode, struct file * filp)
-{
- int ret = 0;
-
- lock_kernel();
- switch (iminor(inode)) {
- case 1:
- filp->f_op = &mem_fops;
- filp->f_mapping->backing_dev_info =
- &directly_mappable_cdev_bdi;
- break;
+static const struct memdev {
+ const char *name;
+ mode_t mode;
+ const struct file_operations *fops;
+ struct backing_dev_info *dev_info;
+} devlist[] = {
+ [1] = { "mem", 0, &mem_fops, &directly_mappable_cdev_bdi },
#ifdef CONFIG_DEVKMEM
- case 2:
- filp->f_op = &kmem_fops;
- filp->f_mapping->backing_dev_info =
- &directly_mappable_cdev_bdi;
- break;
+ [2] = { "kmem", 0, &kmem_fops, &directly_mappable_cdev_bdi },
#endif
- case 3:
- filp->f_op = &null_fops;
- break;
+ [3] = { "null", 0666, &null_fops, NULL },
#ifdef CONFIG_DEVPORT
- case 4:
- filp->f_op = &port_fops;
- break;
+ [4] = { "port", 0, &port_fops, NULL },
#endif
- case 5:
- filp->f_mapping->backing_dev_info = &zero_bdi;
- filp->f_op = &zero_fops;
- break;
- case 7:
- filp->f_op = &full_fops;
- break;
- case 8:
- filp->f_op = &random_fops;
- break;
- case 9:
- filp->f_op = &urandom_fops;
- break;
- case 11:
- filp->f_op = &kmsg_fops;
- break;
+ [5] = { "zero", 0666, &zero_fops, &zero_bdi },
+ [7] = { "full", 0666, &full_fops, NULL },
+ [8] = { "random", 0666, &random_fops, NULL },
+ [9] = { "urandom", 0666, &urandom_fops, NULL },
+ [11] = { "kmsg", 0, &kmsg_fops, NULL },
#ifdef CONFIG_CRASH_DUMP
- case 12:
- filp->f_op = &oldmem_fops;
- break;
+ [12] = { "oldmem", 0, &oldmem_fops, NULL },
#endif
- default:
- unlock_kernel();
- return -ENXIO;
- }
- if (filp->f_op && filp->f_op->open)
- ret = filp->f_op->open(inode,filp);
- unlock_kernel();
- return ret;
+};
+
+static int memory_open(struct inode *inode, struct file *filp)
+{
+ int minor;
+ const struct memdev *dev;
+
+ minor = iminor(inode);
+ if (minor >= ARRAY_SIZE(devlist))
+ return -ENXIO;
+
+ dev = &devlist[minor];
+ if (!dev->fops)
+ return -ENXIO;
+
+ filp->f_op = dev->fops;
+ if (dev->dev_info)
+ filp->f_mapping->backing_dev_info = dev->dev_info;
+
+ if (dev->fops->open)
+ return dev->fops->open(inode, filp);
+
+ return 0;
}
static const struct file_operations memory_fops = {
- .open = memory_open, /* just a selector for the real open */
+ .open = memory_open,
};
-static const struct {
- unsigned int minor;
- char *name;
- umode_t mode;
- const struct file_operations *fops;
-} devlist[] = { /* list of minor devices */
- {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops},
-#ifdef CONFIG_DEVKMEM
- {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops},
-#endif
- {3, "null", S_IRUGO | S_IWUGO, &null_fops},
-#ifdef CONFIG_DEVPORT
- {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops},
-#endif
- {5, "zero", S_IRUGO | S_IWUGO, &zero_fops},
- {7, "full", S_IRUGO | S_IWUGO, &full_fops},
- {8, "random", S_IRUGO | S_IWUSR, &random_fops},
- {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops},
- {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops},
-#ifdef CONFIG_CRASH_DUMP
- {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops},
-#endif
-};
+static char *mem_devnode(struct device *dev, mode_t *mode)
+{
+ if (mode && devlist[MINOR(dev->devt)].mode)
+ *mode = devlist[MINOR(dev->devt)].mode;
+ return NULL;
+}
static struct class *mem_class;
static int __init chr_dev_init(void)
{
- int i;
+ int minor;
int err;
err = bdi_init(&zero_bdi);
printk("unable to get major %d for memory devs\n", MEM_MAJOR);
mem_class = class_create(THIS_MODULE, "mem");
- for (i = 0; i < ARRAY_SIZE(devlist); i++)
- device_create(mem_class, NULL,
- MKDEV(MEM_MAJOR, devlist[i].minor), NULL,
- devlist[i].name);
+ mem_class->devnode = mem_devnode;
+ for (minor = 1; minor < ARRAY_SIZE(devlist); minor++) {
+ if (!devlist[minor].name)
+ continue;
+ device_create(mem_class, NULL, MKDEV(MEM_MAJOR, minor),
+ NULL, devlist[minor].name);
+ }
return 0;
}
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