*/
static inline int uncached_access(struct file *file, unsigned long addr)
{
-#if defined(__i386__) && !defined(__arch_um__)
- /*
- * On the PPro and successors, the MTRRs are used to set
- * memory types for physical addresses outside main memory,
- * so blindly setting PCD or PWT on those pages is wrong.
- * For Pentiums and earlier, the surround logic should disable
- * caching for the high addresses through the KEN pin, but
- * we maintain the tradition of paranoia in this code.
- */
- if (file->f_flags & O_SYNC)
- return 1;
- return !( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability) )
- && addr >= __pa(high_memory);
-#elif defined(__x86_64__) && !defined(__arch_um__)
- /*
- * This is broken because it can generate memory type aliases,
- * which can cause cache corruptions
- * But it is only available for root and we have to be bug-to-bug
- * compatible with i386.
- */
- if (file->f_flags & O_SYNC)
- return 1;
- /* same behaviour as i386. PAT always set to cached and MTRRs control the
- caching behaviour.
- Hopefully a full PAT implementation will fix that soon. */
- return 0;
-#elif defined(CONFIG_IA64)
+#if defined(CONFIG_IA64)
/*
* On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases.
*/
return written;
}
+int __attribute__((weak)) phys_mem_access_prot_allowed(struct file *file,
+ unsigned long pfn, unsigned long size, pgprot_t *vma_prot)
+{
+ return 1;
+}
+
#ifndef __HAVE_PHYS_MEM_ACCESS_PROT
static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
}
#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 int mmap_mem(struct file * file, struct vm_area_struct * vma)
{
size_t size = vma->vm_end - vma->vm_start;
if (!range_is_allowed(vma->vm_pgoff, size))
return -EPERM;
+ if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size,
+ &vma->vm_page_prot))
+ return -EINVAL;
+
vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
size,
vma->vm_page_prot);
+ vma->vm_ops = &mmap_mem_ops;
+
/* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
if (remap_pfn_range(vma,
vma->vm_start,
vma->vm_pgoff,
size,
- vma->vm_page_prot))
+ vma->vm_page_prot)) {
+ unmap_devmem(vma->vm_pgoff, size, vma->vm_page_prot);
return -EAGAIN;
+ }
return 0;
}
+#ifdef CONFIG_DEVKMEM
static int mmap_kmem(struct file * file, struct vm_area_struct * vma)
{
unsigned long pfn;
vma->vm_pgoff = pfn;
return mmap_mem(file, vma);
}
+#endif
#ifdef CONFIG_CRASH_DUMP
/*
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.
*/
*ppos = p;
return virtr + wrote;
}
+#endif
#ifdef CONFIG_DEVPORT
static ssize_t read_port(struct file * file, char __user * buf,
.get_unmapped_area = get_unmapped_area_mem,
};
+#ifdef CONFIG_DEVKMEM
static const struct file_operations kmem_fops = {
.llseek = memory_lseek,
.read = read_kmem,
.open = open_kmem,
.get_unmapped_area = get_unmapped_area_mem,
};
+#endif
static const struct file_operations null_fops = {
.llseek = null_lseek,
filp->f_mapping->backing_dev_info =
&directly_mappable_cdev_bdi;
break;
+#ifdef CONFIG_DEVKMEM
case 2:
filp->f_op = &kmem_fops;
filp->f_mapping->backing_dev_info =
&directly_mappable_cdev_bdi;
break;
+#endif
case 3:
filp->f_op = &null_fops;
break;
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},