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>
asm/elf.h, asm/page.h and asm/user.h don't export to userspace now, so we can
drop #ifdef __KERNEL__ for them.
[k.shutemov@gmail.com: remove #ifdef __KERNEL_]
Signed-off-by: Kirill A. Shutemov <k.shutemov@gmail.com>
Reviewed-by: David Woodhouse <dwmw2@infradead.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Kirill A. Shutemov <k.shutemov@gmail.com>
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>
The following replaces the earlier patches sent. It should address
David Rientjes's comments, and has been compile tested on all the
architectures that it touches, save for parisc.
For the /proc/<pid>/pagemap code[1], we need to able to query how
much virtual address space a particular task has. The trick is
that we do it through /proc and can't use TASK_SIZE since it
references "current" on some arches. The process opening the
/proc file might be a 32-bit process opening a 64-bit process's
pagemap file.
x86_64 already has a TASK_SIZE_OF() macro:
#define TASK_SIZE_OF(child) ((test_tsk_thread_flag(child, TIF_IA32)) ? IA32_PAGE_OFFSET : TASK_SIZE64)
I'd like to have that for other architectures. So, add it
for all the architectures that actually use "current" in
their TASK_SIZE. For the others, just add a quick #define
in sched.h to use plain old TASK_SIZE.
1. http://www.linuxworld.com/news/2007/042407-kernel.html
- MIPS portion from Ralf Baechle <ralf@linux-mips.org>
[akpm@linux-foundation.org: fix mips build]
Signed-off-by: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mark comment as comment, fixes:
include/asm/vga.h:6:8: warning: extra tokens at end of #endif directive
Signed-off-by: Frank Lichtenheld <frank@lichtenheld.de>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
A userspace program may wish to set the mark for each packets its send
without using the netfilter MARK target. Changing the mark can be used
for mark based routing without netfilter or for packet filtering.
It requires CAP_NET_ADMIN capability.
Signed-off-by: Laszlo Attila Toth <panther@balabit.hu>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
There's really no reason not to print more than one character at a
time to the PDC console... Booting is measurably speedier, and now I don't
have to watch individual characters get drawn.
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
arch/parisc/kernel/pci-dma.c: In function 'pa11_dma_map_sg':
arch/parisc/kernel/pci-dma.c:487: error: 'struct scatterlist' has no member named 'page'
arch/parisc/kernel/pci-dma.c: In function 'pa11_dma_unmap_sg':
arch/parisc/kernel/pci-dma.c:508: error: 'struct scatterlist' has no member named 'page'
arch/parisc/kernel/pci-dma.c:508: error: 'struct scatterlist' has no member named 'page'
arch/parisc/kernel/pci-dma.c: In function 'pa11_dma_sync_sg_for_cpu':
arch/parisc/kernel/pci-dma.c:535: error: 'struct scatterlist' has no member named 'page'
arch/parisc/kernel/pci-dma.c:535: error: 'struct scatterlist' has no member named 'page'
arch/parisc/kernel/pci-dma.c: In function 'pa11_dma_sync_sg_for_device':
arch/parisc/kernel/pci-dma.c:545: error: 'struct scatterlist' has no member named 'page'
arch/parisc/kernel/pci-dma.c:545: error: 'struct scatterlist' has no member named 'page'
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Change the page member of the scatterlist structure to be an unsigned
long, and encode more stuff in the lower bits:
- Bits 0 and 1 zero: this is a normal sg entry. Next sg entry is located
at sg + 1.
- Bit 0 set: this is a chain entry, the next real entry is at ->page_link
with the two low bits masked off.
- Bit 1 set: this is the final entry in the sg entry. sg_next() will return
NULL when passed such an entry.
It's thus important that sg table users use the proper accessors to get
and set the page member.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* 'master' of hera.kernel.org:/pub/scm/linux/kernel/git/kyle/parisc-2.6: (29 commits)
[PARISC] fix uninitialized variable warning in asm/rtc.h
[PARISC] Port checkstack.pl to parisc
[PARISC] Make palo target work when $obj != $src
[PARISC] Zap unused variable warnings in pci.c
[PARISC] Fix tests in palo target
[PARISC] Fix palo target
[PARISC] Restore palo target
[PARISC] Attempt to clean up parisc/Makefile
[PARISC] Fix infinite loop in /proc/iomem
[PARISC] Quiet sysfs_create_link __must_check warnings in pdc_stable
[PARISC] Squelch pci_enable_device __must_check warning in superio
[PARISC] Kill off broken irqstack code
[PARISC] Remove hardcoded uses of PAGE_SIZE
[PARISC] Clean up pointless ASM_PAGE_SIZE_DIV use
[PARISC] Kill off the last vestiges of ASM_PAGE_SIZE
[PARISC] Kill off ASM_PAGE_SIZE use
[PARISC] Beautify parisc vmlinux.lds.S
[PARISC] Clean up a resource_size_t warning in sba_iommu
[PARISC] Kill incorrect cast warning in unwinder
[PARISC] Kill zone_to_nid printk warning
...
Fixed trivial conflict in include/asm-parisc/tlbflush.h manually
get_rtc_time, in the case that PDC returns that the battery is bad, returns
an unmodified rtc_time arg to the caller, which then uses uninitialized
values. Fix this by memset-ing the arg with zeroes, so it will at least be
cleared if we return failure.
Spotted by John David Anglin.
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Add CONFIG_IDE_ARCH_OBSOLETE_INIT to drivers/ide/Kconfig and use it instead
of defining IDE_ARCH_OBSOLETE_INIT in <arch/ide.h>.
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
forbid asm/bitops.h direct inclusion
Because of compile errors that may occur after bit changes if asm/bitops.h is
included directly without e.g. linux/kernel.h which includes linux/bitops.h,
forbid direct inclusion of asm/bitops.h. Thanks to Adrian Bunk.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
remove asm/bitops.h includes
including asm/bitops directly may cause compile errors. don't include it
and include linux/bitops instead. next patch will deny including asm header
directly.
Cc: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have the macro _AC() generally available now
so the calculation of PAGE_SIZE can be made
assembler compatible.
Introduce use of _AC() and kill all users of
ASM_PAGE_SIZE.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
