linux.git/arch/ppc/mm/pgtable.c, branch master

powerpc: Remove arch/ppc and include/asm-ppc

2008-06-10T11:40:22+00:00

All the maintained platforms are now in arch/powerpc, so the old
arch/ppc stuff can now go away.

Acked-by: Adrian Bunk 
Acked-by: Arnd Bergmann 
Acked-by: Becky Bruce 
Acked-by: Benjamin Herrenschmidt 
Acked-by: Geert Uytterhoeven 
Acked-by: Grant Likely 
Acked-by: Jochen Friedrich 
Acked-by: John Linn 
Acked-by: Jon Loeliger 
Acked-by: Josh Boyer 
Acked-by: Kumar Gala 
Acked-by: Olof Johansson 
Acked-by: Peter Korsgaard 
Acked-by: Scott Wood 
Acked-by: Sean MacLennan 
Acked-by: Segher Boessenkool 
Acked-by: Stefan Roese 
Acked-by: Stephen Neuendorffer 
Acked-by: Wolfgang Denk 
Signed-off-by: Paul Mackerras

CONFIG_HIGHPTE vs. sub-page page tables.

2008-02-08T17:22:42+00:00

Background: I've implemented 1K/2K page tables for s390.  These sub-page
page tables are required to properly support the s390 virtualization
instruction with KVM.  The SIE instruction requires that the page tables
have 256 page table entries (pte) followed by 256 page status table entries
(pgste).  The pgstes are only required if the process is using the SIE
instruction.  The pgstes are updated by the hardware and by the hypervisor
for a number of reasons, one of them is dirty and reference bit tracking.
To avoid wasting memory the standard pte table allocation should return
1K/2K (31/64 bit) and 2K/4K if the process is using SIE.

Problem: Page size on s390 is 4K, page table size is 1K or 2K.  That means
the s390 version for pte_alloc_one cannot return a pointer to a struct
page.  Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one
cannot return a pointer to a pte either, since that would require more than
32 bit for the return value of pte_alloc_one (and the pte * would not be
accessible since its not kmapped).

Solution: The only solution I found to this dilemma is a new typedef: a
pgtable_t.  For s390 pgtable_t will be a (pte *) - to be introduced with a
later patch.  For everybody else it will be a (struct page *).  The
additional problem with the initialization of the ptl lock and the
NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and
a destructor pgtable_page_dtor.  The page table allocation and free
functions need to call these two whenever a page table page is allocated or
freed.  pmd_populate will get a pgtable_t instead of a struct page pointer.
 To get the pgtable_t back from a pmd entry that has been installed with
pmd_populate a new function pmd_pgtable is added.  It replaces the pmd_page
call in free_pte_range and apply_to_pte_range.

Signed-off-by: Martin Schwidefsky 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

add mm argument to pte/pmd/pud/pgd_free

2008-02-05T17:44:18+00:00

(with Martin Schwidefsky )

The pgd/pud/pmd/pte page table allocation functions get a mm_struct pointer as
first argument.  The free functions do not get the mm_struct argument.  This
is 1) asymmetrical and 2) to do mm related page table allocations the mm
argument is needed on the free function as well.

[kamalesh@linux.vnet.ibm.com: i386 fix]
[akpm@linux-foundation.org: coding-syle fixes]
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Martin Schwidefsky 
Cc: 
Signed-off-by: Kamalesh Babulal 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PPC] Remove 85xx from arch/ppc

2008-01-28T14:33:10+00:00

85xx exists in arch/powerpc as well as cuImage support to boot from
a u-boot that doesn't support device trees.

Signed-off-by: Kumar Gala

[POWERPC] Remove APUS support from arch/ppc

2007-09-17T05:15:04+00:00

Current status of APUS:
- arch/powerpc/: removed in 2.6.23
- arch/ppc/: marked BROKEN since 2 years

This therefore removes the remaining parts of APUS support from
arch/ppc, include/asm-ppc, arch/powerpc and include/asm-powerpc.

Signed-off-by: Adrian Bunk 
Signed-off-by: Paul Mackerras

[PPC] Fix modpost warning

2007-05-23T12:59:06+00:00

Mark pte_alloc_one_kernel as __init_refok to fix the following warning:

WARNING: arch/ppc/mm/built-in.o(.text+0x1114): Section mismatch: reference to .init.text:early_get_page (between 'pte_alloc_one_kernel' and 'v_mapped_by_tlbcam')

Signed-off-by: Kumar Gala

[POWERPC] Fix is_power_of_4(x) compile error

2007-02-09T15:30:05+00:00

When building an 85xx kernel we get:

  CC      arch/powerpc/mm/pgtable_32.o
arch/powerpc/mm/pgtable_32.c: In function 'io_block_mapping':
arch/powerpc/mm/pgtable_32.c:330: error: expected identifier before '(' token
arch/powerpc/mm/pgtable_32.c:330: error: expected statement before ')' token

The is_power_of_2(x) fixup patch left an extra ')' on the is_power_of_4 macro.
There is a similiar issue on the arch/ppc side.

Signed-off-by: Kumar Gala

[POWERPC] Add "is_power_of_2" checking to log2.h.

2007-02-07T03:03:19+00:00

Add the inline function "is_power_of_2()" to log2.h, where the value
zero is *not* considered to be a power of two.

Signed-off-by: Robert P. J. Day 
Acked-by: Kumar Gala 
Signed-off-by: Paul Mackerras

Remove obsolete #include

2006-06-30T17:25:36+00:00

Signed-off-by: Jörn Engel 
Signed-off-by: Adrian Bunk

[PATCH] lock PTE before updating it in 440/BookE page fault handler

2006-03-29T02:44:15+00:00

Fix 44x and BookE page fault handler to correctly lock PTE before
trying to pte_update() it, otherwise this PTE might be swapped out
after pte_present() check but before pte_uptdate() call, resulting in
corrupted PTE. This can happen with enabled preemption and low memory
condition.

Signed-off-by: Eugene Surovegin 
Signed-off-by: Paul Mackerras