Turn um_virt_to_phys into virt_to_pte, cleaning up a horrid interface.
It's also made non-static and declared in pgtable.h because it'll be

needed when the stubs get a vma.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>

---

 arch/um/kernel/skas/uaccess.c |   56 +++++++++++++++++-------------------------

 include/asm-um/pgtable.h      |    3 ++

 2 files changed, 26 insertions(+), 33 deletions(-)
Index: linux-2.6.22/arch/um/kernel/skas/uaccess.c

===================================================================

--- linux-2.6.22.orig/arch/um/kernel/skas/uaccess.c	2007-11-16 15:16:54.000000000 -0500

+++ linux-2.6.22/arch/um/kernel/skas/uaccess.c	2007-11-16 15:40:25.000000000 -0500

@@ -13,70 +13,60 @@

 #include "kern_util.h"

 #include "os.h"
-static void *um_virt_to_phys(struct task_struct *task, unsigned long addr,

-			     pte_t *pte_out)

+pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr)

 {

 	pgd_t *pgd;

 	pud_t *pud;

 	pmd_t *pmd;

-	pte_t *pte;

-	pte_t ptent;
-	if (task->mm == NULL)

-		return ERR_PTR(-EINVAL);

-	pgd = pgd_offset(task->mm, addr);

+	if (mm == NULL)

+		return NULL;

+

+	pgd = pgd_offset(mm, addr);

 	if (!pgd_present(*pgd))

-		return ERR_PTR(-EINVAL);

+		return NULL;
 	pud = pud_offset(pgd, addr);

 	if (!pud_present(*pud))

-		return ERR_PTR(-EINVAL);

+		return NULL;
 	pmd = pmd_offset(pud, addr);

 	if (!pmd_present(*pmd))

-		return ERR_PTR(-EINVAL);

-

-	pte = pte_offset_kernel(pmd, addr);

-	ptent = *pte;

-	if (!pte_present(ptent))

-		return ERR_PTR(-EINVAL);

+		return NULL;
-	if (pte_out != NULL)

-		*pte_out = ptent;

-	return (void *) (pte_val(ptent) & PAGE_MASK) + (addr & ~PAGE_MASK);

+	return pte_offset_kernel(pmd, addr);

 }
-static unsigned long maybe_map(unsigned long virt, int is_write)

+static pte_t *maybe_map(unsigned long virt, int is_write)

 {

-	pte_t pte;

-	int err;

+	pte_t *pte = virt_to_pte(current->mm, virt);

+	int err, dummy_code;
-	void *phys = um_virt_to_phys(curren...
[ message continues ]

-

No, because if the page isn't mapped, handle_page_fault would have

returned non-zero, and we would have already returned.
This is leaving aside issues of whether the page could have been

unmapped by another CPU (which isn't an issue right now, and for which

I have a patch to fix anyway).
				Jeff
--

Work email - jdike at linux dot intel dot com

-