lkml.org 
[lkml]   [2004]   [Sep]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[vm 1/76] introduce remap_pfn_range()
This patch introduces remap_pfn_range(), destined to replace
remap_page_range(). In the sequel, the callers of remap_page_range()
will be converted one at a time.

By using a pfn to specify its physical address argument,
remap_pfn_range() resolves a longstanding physical address overflow
issue.


Index: mm3-2.6.9-rc2/include/linux/mm.h
===================================================================
--- mm3-2.6.9-rc2.orig/include/linux/mm.h 2004-09-24 19:17:00.863688360 -0700
+++ mm3-2.6.9-rc2/include/linux/mm.h 2004-09-24 22:01:48.366559448 -0700
@@ -856,8 +856,15 @@
extern struct page * vmalloc_to_page(void *addr);
extern struct page * follow_page(struct mm_struct *mm, unsigned long address,
int write);
-extern int remap_page_range(struct vm_area_struct *vma, unsigned long from,
- unsigned long to, unsigned long size, pgprot_t prot);
+int remap_pfn_range(struct vm_area_struct *, unsigned long,
+ unsigned long, unsigned long, pgprot_t);
+
+static inline
+int remap_page_range(struct vm_area_struct *vma, unsigned long uvaddr,
+ unsigned long paddr, unsigned long size, pgprot_t prot)
+{
+ return remap_pfn_range(vma, uvaddr, paddr >> PAGE_SHIFT, size, prot);
+}

#ifdef CONFIG_PROC_FS
void __vm_stat_account(struct mm_struct *, unsigned long, struct file *, long);
Index: mm3-2.6.9-rc2/mm/memory.c
===================================================================
--- mm3-2.6.9-rc2.orig/mm/memory.c 2004-09-24 17:37:15.000000000 -0700
+++ mm3-2.6.9-rc2/mm/memory.c 2004-09-24 21:58:50.300629584 -0700
@@ -945,16 +945,14 @@
* in null mappings (currently treated as "copy-on-access")
*/
static inline void remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
- unsigned long phys_addr, pgprot_t prot)
+ unsigned long pfn, pgprot_t prot)
{
unsigned long end;
- unsigned long pfn;

address &= ~PMD_MASK;
end = address + size;
if (end > PMD_SIZE)
end = PMD_SIZE;
- pfn = phys_addr >> PAGE_SHIFT;
do {
BUG_ON(!pte_none(*pte));
if (!pfn_valid(pfn) || PageReserved(pfn_to_page(pfn)))
@@ -966,7 +964,7 @@
}

static inline int remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
- unsigned long phys_addr, pgprot_t prot)
+ unsigned long pfn, pgprot_t prot)
{
unsigned long base, end;

@@ -975,12 +973,12 @@
end = address + size;
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
- phys_addr -= address;
+ pfn -= address >> PAGE_SHIFT;
do {
pte_t * pte = pte_alloc_map(mm, pmd, base + address);
if (!pte)
return -ENOMEM;
- remap_pte_range(pte, base + address, end - address, address + phys_addr, prot);
+ remap_pte_range(pte, base + address, end - address, pfn + (address >> PAGE_SHIFT), prot);
pte_unmap(pte);
address = (address + PMD_SIZE) & PMD_MASK;
pmd++;
@@ -989,7 +987,7 @@
}

/* Note: this is only safe if the mm semaphore is held when called. */
-int remap_page_range(struct vm_area_struct *vma, unsigned long from, unsigned long phys_addr, unsigned long size, pgprot_t prot)
+int remap_pfn_range(struct vm_area_struct *vma, unsigned long from, unsigned long pfn, unsigned long size, pgprot_t prot)
{
int error = 0;
pgd_t * dir;
@@ -997,7 +995,7 @@
unsigned long end = from + size;
struct mm_struct *mm = vma->vm_mm;

- phys_addr -= from;
+ pfn -= from >> PAGE_SHIFT;
dir = pgd_offset(mm, from);
flush_cache_range(vma, beg, end);
if (from >= end)
@@ -1009,7 +1007,7 @@
error = -ENOMEM;
if (!pmd)
break;
- error = remap_pmd_range(mm, pmd, from, end - from, phys_addr + from, prot);
+ error = remap_pmd_range(mm, pmd, from, end - from, pfn + (from >> PAGE_SHIFT), prot);
if (error)
break;
from = (from + PGDIR_SIZE) & PGDIR_MASK;
@@ -1022,8 +1020,7 @@
spin_unlock(&mm->page_table_lock);
return error;
}
-
-EXPORT_SYMBOL(remap_page_range);
+EXPORT_SYMBOL(remap_pfn_range);

/*
* Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when
Index: mm3-2.6.9-rc2/mm/nommu.c
===================================================================
--- mm3-2.6.9-rc2.orig/mm/nommu.c 2004-09-24 02:10:30.000000000 -0700
+++ mm3-2.6.9-rc2/mm/nommu.c 2004-09-24 22:06:16.400812048 -0700
@@ -560,7 +560,7 @@
return NULL;
}

-int remap_page_range(struct vm_area_struct *vma, unsigned long from,
+int remap_pfn_range(struct vm_area_struct *vma, unsigned long from,
unsigned long to, unsigned long size, pgprot_t prot)
{
return -EPERM;
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2005-03-22 14:06    [W:0.039 / U:1.196 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site