lkml.org 
[lkml]   [2010]   [Nov]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
SubjectRe: [PATCH v2 01/20] ARM: LPAE: Use PMD_(SHIFT|SIZE|MASK) instead of PGDIR_*
From
Date
On Mon, 2010-11-22 at 12:43 +0000, Russell King - ARM Linux wrote:
> On Fri, Nov 12, 2010 at 06:00:21PM +0000, Catalin Marinas wrote:
> > diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
> > index 8c19595..40b386c 100644
> > --- a/arch/arm/kernel/smp.c
> > +++ b/arch/arm/kernel/smp.c
> > @@ -78,7 +78,7 @@ static inline void identity_mapping_add(pgd_t *pgd, unsigned long start,
> > if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
> > prot |= PMD_BIT4;
> >
> > - for (addr = start & PGDIR_MASK; addr < end;) {
> > + for (addr = start & PMD_MASK; addr < end;) {
> > pmd = pmd_offset(pgd + pgd_index(addr), addr);
> > pmd[0] = __pmd(addr | prot);
> > addr += SECTION_SIZE;
> > @@ -95,7 +95,7 @@ static inline void identity_mapping_del(pgd_t *pgd, unsigned long start,
> > unsigned long addr;
> > pmd_t *pmd;
> >
> > - for (addr = start & PGDIR_MASK; addr < end; addr += PGDIR_SIZE) {
> > + for (addr = start & PMD_MASK; addr < end; addr += PMD_SIZE) {
> > pmd = pmd_offset(pgd + pgd_index(addr), addr);
> > pmd[0] = __pmd(0);
> > pmd[1] = __pmd(0);
> ...
> > @@ -1068,12 +1068,12 @@ void setup_mm_for_reboot(char mode)
> > base_pmdval |= PMD_BIT4;
> >
> > for (i = 0; i < FIRST_USER_PGD_NR + USER_PTRS_PER_PGD; i++, pgd++) {
> > - unsigned long pmdval = (i << PGDIR_SHIFT) | base_pmdval;
> > + unsigned long pmdval = (i << PMD_SHIFT) | base_pmdval;
> > pmd_t *pmd;
> >
> > - pmd = pmd_off(pgd, i << PGDIR_SHIFT);
> > + pmd = pmd_off(pgd, i << PMD_SHIFT);
> > pmd[0] = __pmd(pmdval);
> > - pmd[1] = __pmd(pmdval + (1 << (PGDIR_SHIFT - 1)));
> > + pmd[1] = __pmd(pmdval + (1 << (PMD_SHIFT - 1)));
> > flush_pmd_entry(pmd);
> > }
> >
>
> This lot really does need unifying - and in any case this last addition
> should be using 'SECTION SIZE' not something related to PMD shifts.

On the classic page tables, the PMD_SHIFT is 21 while the SECTION_SHIFT
is 20. They have slightly different meaning.

But we currently have some hacks to cope with PMD_SHIFT being 21 by
writing the pmd[0] and pmd[1] in the same call. The way I see to use
SECTION_SHIFT is to drop the pmd[] array (but haven't looked closely
enough). With LPAE I have a few #ifndef around pmd[1] setting.

> Strangely, it's something I've done over the weekend...

OK, the more clean-up the better.

--
Catalin




\
 
 \ /
  Last update: 2010-11-22 14:15    [from the cache]
©2003-2014 Jasper Spaans. Advertise on this site