linux/arch/microblaze
Russell King 4b3073e1c5 MM: Pass a PTE pointer to update_mmu_cache() rather than the PTE itself
On VIVT ARM, when we have multiple shared mappings of the same file
in the same MM, we need to ensure that we have coherency across all
copies.  We do this via make_coherent() by making the pages
uncacheable.

This used to work fine, until we allowed highmem with highpte - we
now have a page table which is mapped as required, and is not available
for modification via update_mmu_cache().

Ralf Beache suggested getting rid of the PTE value passed to
update_mmu_cache():

  On MIPS update_mmu_cache() calls __update_tlb() which walks pagetables
  to construct a pointer to the pte again.  Passing a pte_t * is much
  more elegant.  Maybe we might even replace the pte argument with the
  pte_t?

Ben Herrenschmidt would also like the pte pointer for PowerPC:

  Passing the ptep in there is exactly what I want.  I want that
  -instead- of the PTE value, because I have issue on some ppc cases,
  for I$/D$ coherency, where set_pte_at() may decide to mask out the
  _PAGE_EXEC.

So, pass in the mapped page table pointer into update_mmu_cache(), and
remove the PTE value, updating all implementations and call sites to
suit.

Includes a fix from Stephen Rothwell:

  sparc: fix fallout from update_mmu_cache API change

  Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-02-20 16:41:46 +00:00
..
boot microblaze: support U-BOOT image format 2009-12-14 08:44:59 +01:00
configs microblaze: Disable heartbeat/enable emaclite in defconfigs 2009-09-24 10:30:27 +02:00
include/asm MM: Pass a PTE pointer to update_mmu_cache() rather than the PTE itself 2010-02-20 16:41:46 +00:00
kernel microblaze: pci_controller->arch_data really is a struct device_node * 2010-01-18 16:36:07 +01:00
lib microblaze: Simple __copy_tofrom_user for noMMU 2009-12-14 08:45:03 +01:00
mm microblaze: Remove show_tmem function 2009-12-14 08:45:11 +01:00
oprofile microblaze: Core oprofile configs and hooks 2009-12-14 08:45:07 +01:00
platform microblaze: Use lowest-common-denominator default CPU settings 2009-12-14 08:45:02 +01:00
Kconfig microblaze: Add missing double apostrophe in Kconfig 2010-01-18 16:35:52 +01:00
Kconfig.debug microblaze: Add TRACE_IRQFLAGS_SUPPORT 2009-12-14 08:40:09 +01:00
Makefile microblaze: Core oprofile configs and hooks 2009-12-14 08:45:07 +01:00