Implement 4-level pagetables for ppc64
This patch implements full four-level page tables for ppc64, thereby
extending the usable user address range to 44 bits (16T).
The patch uses a full page for the tables at the bottom and top level,
and a quarter page for the intermediate levels. It uses full 64-bit
pointers at every level, thus also increasing the addressable range of
physical memory. This patch also tweaks the VSID allocation to allow
matching range for user addresses (this halves the number of available
contexts) and adds some #if and BUILD_BUG sanity checks.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Currently ppc64 has two mm_structs for the kernel, init_mm and also
ioremap_mm. The latter really isn't necessary: this patch abolishes it,
instead restricting vmallocs to the lower 1TB of the init_mm's range and
placing io mappings in the upper 1TB. This simplifies the code in a number
of places and eliminates an unecessary set of pagetables. It also tweaks
the unmap/free path a little, allowing us to remove the unmap_im_area() set
of page table walkers, replacing them with unmap_vm_area().
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch started as simply removing a few never-used macros from
asm-ppc64/pgtable.h, then kind of grew. It now makes a bunch of
cleanups to the ppc64 low-level header files (with corresponding
changes to .c files where necessary) such as:
- Abolishing never-used macros
- Eliminating multiple #defines with the same purpose
- Removing pointless macros (cases where just expanding the
macro everywhere turns out clearer and more sensible)
- Removing some cases where macros which could be defined in
terms of each other weren't
- Moving imalloc() related definitions from pgtable.h to their
own header file (imalloc.h)
- Re-arranging headers to group things more logically
- Moving all VSID allocation related things to mmu.h, instead
of being split between mmu.h and mmu_context.h
- Removing some reserved space for flags from the PMD - we're
not using it.
- Fix some bugs which broke compile with STRICT_MM_TYPECHECKS.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
