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 <schwidefsky@de.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(with Martin Schwidefsky <schwidefsky@de.ibm.com>)
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 <benh@kernel.crashing.org>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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 <galak@kernel.crashing.org>
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 <bunk@stusta.de>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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 <galak@kernel.crashing.org>
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 <galak@kernel.crashing.org>
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 <rpjday@mindspring.com>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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 <ebs@ebshome.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
32-bit CHRP machines are now supported only in arch/powerpc, as are
all 64-bit PowerPC processors. This means that we don't use
Open Firmware on any platform in arch/ppc any more.
This makes PReP support a single-platform option like every other
platform support option in arch/ppc now, thus CONFIG_PPC_MULTIPLATFORM
is gone from arch/ppc. CONFIG_PPC_PREP is the option that selects
PReP support and is generally what has replaced
CONFIG_PPC_MULTIPLATFORM within arch/ppc.
_machine is all but dead now, being #defined to 0.
Updated Makefiles, comments and Kconfig options generally to reflect
these changes.
Signed-off-by: Paul Mackerras <paulus@samba.org>
First step in pushing down the page_table_lock. init_mm.page_table_lock has
been used throughout the architectures (usually for ioremap): not to serialize
kernel address space allocation (that's usually vmlist_lock), but because
pud_alloc,pmd_alloc,pte_alloc_kernel expect caller holds it.
Reverse that: don't lock or unlock init_mm.page_table_lock in any of the
architectures; instead rely on pud_alloc,pmd_alloc,pte_alloc_kernel to take
and drop it when allocating a new one, to check lest a racing task already
did. Similarly no page_table_lock in vmalloc's map_vm_area.
Some temporary ugliness in __pud_alloc and __pmd_alloc: since they also handle
user mms, which are converted only by a later patch, for now they have to lock
differently according to whether or not it's init_mm.
If sources get muddled, there's a danger that an arch source taking
init_mm.page_table_lock will be mixed with common source also taking it (or
neither take it). So break the rules and make another change, which should
break the build for such a mismatch: remove the redundant mm arg from
pte_alloc_kernel (ppc64 scrapped its distinct ioremap_mm in 2.6.13).
Exceptions: arm26 used pte_alloc_kernel on user mm, now pte_alloc_map; ia64
used pte_alloc_map on init_mm, now pte_alloc_kernel; parisc had bad args to
pmd_alloc and pte_alloc_kernel in unused USE_HPPA_IOREMAP code; ppc64
map_io_page forgot to unlock on failure; ppc mmu_mapin_ram and ppc64 im_free
took page_table_lock for no good reason.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Made the number of TLB CAM entries private and converted the board
consumers to use num_tlbcam_entries which is setup at boot time from
configuration registers. This way the only consumers of the #define
NUM_TLBCAMS are the arrays used to manage the TLB.
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
CONFIG_PTE_64BIT & CONFIG_PHYS_64BIT are not currently consistently used in
the code base. Fixed up the usage such that CONFIG_PTE_64BIT is used when we
have a 64-bit PTE regardless of physical address width. CONFIG_PHYS_64BIT is
used if the physical address width is larger than 32-bits, regardless of PTE
size.
These changes required a few sub-arch specific ifdef's to be fixed and the
introduction of a physical address format string.
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Martin Schwidefsky