XIP kernels need to know the start/end of text, but we were
missing the declaration of _etext in mmu.c. Add it.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This is an updated version of Eric Biederman's is_init() patch.
(http://lkml.org/lkml/2006/2/6/280). It applies cleanly to 2.6.18-rc3 and
replaces a few more instances of ->pid == 1 with is_init().
Further, is_init() checks pid and thus removes dependency on Eric's other
patches for now.
Eric's original description:
There are a lot of places in the kernel where we test for init
because we give it special properties. Most significantly init
must not die. This results in code all over the kernel test
->pid == 1.
Introduce is_init to capture this case.
With multiple pid spaces for all of the cases affected we are
looking for only the first process on the system, not some other
process that has pid == 1.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: <lxc-devel@lists.sourceforge.net>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make PROT_WRITE imply PROT_READ for a number of architectures which don't
support write only in hardware.
While looking at this, I noticed that some architectures which do not
support write only mappings already take the exact same approach. For
example, in arch/alpha/mm/fault.c:
"
if (cause < 0) {
if (!(vma->vm_flags & VM_EXEC))
goto bad_area;
} else if (!cause) {
/* Allow reads even for write-only mappings */
if (!(vma->vm_flags & (VM_READ | VM_WRITE)))
goto bad_area;
} else {
if (!(vma->vm_flags & VM_WRITE))
goto bad_area;
}
"
Thus, this patch brings other architectures which do not support write only
mappings in-line and consistent with the rest. I've verified the patch on
ia64, x86_64 and x86.
Additional discussion:
Several architectures, including x86, can not support write-only mappings.
The pte for x86 reserves a single bit for protection and its two states are
read only or read/write. Thus, write only is not supported in h/w.
Currently, if i 'mmap' a page write-only, the first read attempt on that page
creates a page fault and will SEGV. That check is enforced in
arch/blah/mm/fault.c. However, if i first write that page it will fault in
and the pte will be set to read/write. Thus, any subsequent reads to the page
will succeed. It is this inconsistency in behavior that this patch is
attempting to address. Furthermore, if the page is swapped out, and then
brought back the first read will also cause a SEGV. Thus, any arbitrary read
on a page can potentially result in a SEGV.
According to the SuSv3 spec, "if the application requests only PROT_WRITE, the
implementation may also allow read access." Also as mentioned, some
archtectures, such as alpha, shown above already take the approach that i am
suggesting.
The counter-argument to this raised by Arjan, is that the kernel is enforcing
the write only mapping the best it can given the h/w limitations. This is
true, however Alan Cox, and myself would argue that the inconsitency in
behavior, that is applications can sometimes work/sometimes fails is highly
undesireable. If you read through the thread, i think people, came to an
agreement on the last patch i posted, as nobody has objected to it...
Signed-off-by: Jason Baron <jbaron@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Andi Kleen <ak@muc.de>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Ian Molton <spyro@f2s.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In nommu mode, the exception vector location depends on the platforms.
Some of the implementations may have some special exception control
forwarding method in their ROM/flash and for some of them has its own
re-mapping mechanism by the h/w.
This patch introduces a special configuration CONFIG_CPU_HIGH_VECTOR which
turns on the CR_V bit in nommu mode. The CR_V bit is turned off by default.
This feature depends on CP15 and does not supported by ARM740.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There is no FSR/FAR register on no-CP15 or MPU cores. This patch adds a
dummy abort handler which returns zero for the base restored Data Abort
model !CPU_CP15_MMU cores. The abort-lv4t.S is still used with the fix-up
for the base updated Data Abort model cores.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds ARM946E-S core support which has typically 8KB I&D cache.
It has a MPU and supports ARMv5TE instruction set.
Because the ARM946E-S core can be synthesizable with various cache size,
CONFIG_CPU_DCACHE_SIZE is defined for vendor specific configurations.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds ARM940T core support which has 4KB D-cache, 4KB I-cache
and a MPU.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds ARM9TDMI core support which has no cache and no CP15
register(no memory control unit).
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds ARM740T core support which has a MPU and 4KB or 8KB cache.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds ARM7TDMI core support which has no cache and no CP15
register(no memory control unit).
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
All the current CP15 access codes in ARM arch can be categorized and
conditioned by the defines as follows:
Related operation Safe condition
a. any CP15 access !CPU_CP15
b. alignment trap CPU_CP15_MMU
c. D-cache(C-bit) CPU_CP15
d. I-cache CPU_CP15 && !( CPU_ARM610 || CPU_ARM710 ||
CPU_ARM720 || CPU_ARM740 ||
CPU_XSCALE || CPU_XSC3 )
e. alternate vector CPU_CP15 && !CPU_ARM740
f. TTB CPU_CP15_MMU
g. Domain CPU_CP15_MMU
h. FSR/FAR CPU_CP15_MMU
For example, alternate vector is supported if and only if
"CPU_CP15 && !CPU_ARM740" is satisfied.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
By merging of uClinux/ARM, we need to treat various CPU cores which have
MMU, MPU or even none for memory management. The memory management
coprocessors are controlled by CP15 register set and the ARM core family
can be categorized by 5 groups by the register ;
G-a. CP15 is MMU : 610, 710, 720, 920, 922, 925, 926, 1020, 1020e, 1022,
v6 and the derivations sa1100, sa110, xscale, xsc3.
G-b. CP15 is MPU : 740, 940, 946, 996, 1156.
G-c. CP15 is MPU or MMU : 1026 (selectable by schematic design)
G-d. CP15 is exist, but nothing for memory managemnt : 966, 968.
G-e. no-CP15 : 7tdmi, 9tdmi, 9e, 9ej
This patch defines CPU_CP15, CPU_CP15_MMU and CPU_CP15_MPU. Thus the
family can be defined as :
- CPU_CP15 only : G-d
- CPU_CP15_MMU(implies CPU_CP15) : G-a, G-c(selectable)
- CPU_CP15_MPU(implies CPU_CP15) : G-b, G-c(selectable)
- !CPU_CP15 : G-e
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Since do_bad_area() always takes the currently active task and
(supposed to) take the currently active MM, there's no point passing
them to this function. Instead, obtain references to them inside
do_bad_area().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
mm-armv.c now only contains the pgd allocation/freeing code, so
rename it to have a more sensible filename.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If we're going to have mmu.c for code which is specific to the MMU
machines, we might as well move the other MMU initialisation
specific code from mm-armv.c into this new file. This also allows
us to make some functions static.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
nommu does not require the page table manipulation code in the
bootmem initialisation paths. Move this into separate inline
functions.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The ARM XIP_KERNEL map created in devicemaps_init() is wrong.
The map.pfn is rounded down to an even 1MiB section boundary
which results in va/pa translations errors when XIP_PHYS_ADDR
starts on an odd 1MiB boundary and this causes the kernel to
hang. This patch fixes ARM XIP_KERNEL translation errors for
the odd 1MiB XIP_PHYS_ADDR boundary case.
Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
One of the changes necessary for shared page tables is to standardize the
pxx_page macros. pte_page and pmd_page have always returned the struct
page associated with their entry, while pte_page_kernel and pmd_page_kernel
have returned the kernel virtual address. pud_page and pgd_page, on the
other hand, return the kernel virtual address.
Shared page tables needs pud_page and pgd_page to return the actual page
structures. There are very few actual users of these functions, so it is
simple to standardize their usage.
Since this is basic cleanup, I am submitting these changes as a standalone
patch. Per Hugh Dickins' comments about it, I am also changing the
pxx_page_kernel macros to pxx_page_vaddr to clarify their meaning.
Signed-off-by: Dave McCracken <dmccr@us.ibm.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix thinko in the flush_ptrace_access() "if (expr)" for the ARM
VIPT non-aliasing cache case. We only need to flush cache when
VM_EXEC is set in vma->vm_flags but "if (expr) always evaluates
to true on UP systems for the ARM VIPT non-aliasing cache case.
Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Split the iop3xx mach type into iop32x and iop33x -- split the config
symbols, and move the code in the mach-iop3xx directory to the mach-iop32x
and mach-iop33x directories.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On stepping A0/A1 of the 80200, invalidating D-cache by line doesn't
clear the dirty bits, which means that if we invalidate a dirty line,
the dirty data can still be written back to memory later on.
To work around this, dma_inv_range() on these two processors is
implemented as dma_flush_range() (i.e. do a clean D-cache line before
doing the invalidate D-cache line.) For this, we currently have a
processor ID check in xscale_dma_inv_range(), but a better solution
is to add a separate cache_fns and proc_info for A0/A1 80200.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Prevent userland from mapping in physical address regions >= 4G by
checking for that in valid_mmap_phys_addr_range().
Unfortunately, we cannot override valid_mmap_phys_addr_range() without
also overriding valid_phys_addr_range(), so copy drivers/char/mem.c's
version of valid_phys_addr_range() over to arch/arm/mm/mmap.c as well.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rename mmu.c to context.c - it's the ARMv6 ASID context handling
code rather than generic "mmu" handling code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move top_pmd into arch/arm/mm/mm.h - nothing outside arch/arm/mm
references it.
Move the repeated definition of TOP_PTE into mm/mm.h, as well as
a few function prototypes.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Dan Williams
commit a6a38a6622 changed the iop321 id to a value that does not work with all platforms. Change the mask to permit bit 11. Tested on an iq80321 600Mhz CRB.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Catalin Marinas
The ARM926EJ-S CPU has the VFP coprocessor and therefore it should be shown
in the /proc/cpuinfo if CONFIG_VFP is enabled.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from George G. Davis
Resolve ARM1136 VIPT non-aliasing cache coherency issues observed when
using ptrace to set breakpoints and cleanup copy_{to,from}_user_page()
while we're here as requested by Russell King because "it's also far
too heavy on non-v6 CPUs".
NOTES:
1. Only access_process_vm() calls copy_{to,from}_user_page().
2. access_process_vm() calls get_user_pages() to pin down the "page".
3. get_user_pages() calls flush_dcache_page(page) which ensures cache
coherency between kernel and userspace mappings of "page". However
flush_dcache_page(page) may not invalidate I-Cache over this range
for all cases, specifically, I-Cache is not invalidated for the VIPT
non-aliasing case. So memory is consistent between kernel and user
space mappings of "page" but I-Cache may still be hot over this
range. IOW, we don't have to worry about flush_cache_page() before
memcpy().
4. Now, for the copy_to_user_page() case, after memcpy(), we must flush
the caches so memory is consistent with kernel cache entries and
invalidate the I-Cache if this mm region is executable. We don't
need to do anything after memcpy() for the copy_from_user_page()
case since kernel cache entries will be invalidated via the same
process above if we access "page" again. The flush_ptrace_access()
function (borrowed from SPARC64 implementation) is added to handle
cache flushing after memcpy() for the copy_to_user_page() case.
Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
On armv4t systems, we have always compiled the kernel with -march=armv4
instead of -march=armv4t, which means that any use of bx will bomb out.
Commit ba9b5d7637 introduced the use of
bx in the kernel, which means we need to compile with -march=armv4t on
armv4t systems now.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Catalin Marinas
This patch adds #ifdef around some variables in the arch/arm/mm/ioremap.c
file.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from George G. Davis
As reported by various folks on the ARM Linux kernel mailing list,
the video-buf.ko driver has undefined references on all ARM machines
which use it as observed during `make modules`:
Warning: "v4wb_clear_user_page" [drivers/media/video/video-buf.ko] undefined!
Similar warnings exist for all ARM machines which use this driver.
So this change adds the missing EXPORT_SYMBOLs to allow using this
driver as a module.
Signed-off-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
The IOP 80219 xscale CPU is a stripped down version of the IOP32x.
But the fact that the 80219 and IOP32x are very similar doesn't mean
that they need to share a cpu table entry. It's also somewhat confusing
for the end user to see the 80219 reported as an IOP32x, so this patch
splits the IOP32x cpu table entry to make a separate entry for the
80219.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
No need for 'cr' to be a local variable, which is unused in the
SMP case, and only used once in the UP case. Just call get_cr()
directly.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
Commit ff0daca525 broke the SMP build,
this patch fixes it up again.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
For several proc-<cputype>.S files the include of proc-macros.S is
missing. Make it compile and work again.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Nicolas Pitre
According to the Intel PXA27x Processor Family Specification
Update document (doc.nr. 280071-009) erratum E7, some care must be taken
to locate the disabling and re-enabling of the MMU to the beginning of a
cache line to avoid problems in some circumstances.
Credits to Simon Vogl <simon.vogl@researchstudios.at> for bringing this
up.
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Lennert Buytenhek
Analogous to the previous patch that allows ioremap() to use section
mappings, this patch allows ioremap() to use supersection mappings.
Original patch by Deepak Saxena.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Conversion of nr_page_table_pages to a per zone counter
[akpm@osdl.org: bugfix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Allow section mappings to be setup using ioremap() and torn down
with iounmap(). This requires additional support in the MM
context switch to ensure that mappings are properly synchronised
when mapped in.
Based an original implementation by Deepak Saxena, reworked and
ARMv6 support added by rmk.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On some CPUs, bit 4 of section mappings means "update the
cache when written to". On others, this bit is required to
be one, and others it's required to be zero. Finally, on
ARMv6 and above, setting it turns on "no execute" and prevents
speculative prefetches.
With all these combinations, no one value fits all CPUs, so we
have to pick a value depending on the CPU type, and the area
we're mapping.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Andrew Victor
This prepares the way for adding support for the new Atmel AT91SAM926x
processors.
Major changes:
- Rename time.c to at91rm9200_time.c
- Rename common.c to at91rm9200.c
- Introduce ARCH_AT91, of which ARCH_AT91RM9200, ARCH_AT91SAM9260 and
ARCH_AT91SAM9261 are dependent.
Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Most MMU-based CPUs have a restriction on the setting of the data cache
enable and mmu enable bits in the control register, whereby if the data
cache is enabled, the MMU must also be enabled. Enabling the data
cache without the MMU is an invalid combination.
However, there are CPUs where the data cache can be enabled without the
MMU.
In order to allow these CPUs to take advantage of that, provide a
method whereby each proc-*.S file defines the control regsiter value
for use with nommu (with the MMU disabled.) Later on, when we add
support for enabling the MMU on these devices, we can adjust the
"crval" macro to also enable the data cache for nommu.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The "id(wb)BRR" suffix reports which CPU debugging options were (or
were not) selected at kernel build time. Rather than have every
proc-*.S file implement this, report the control register value,
from which this information can be deduced.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In noMMU mode, various of functions which are defined in mm/proc-*.S
is not valid or needed to be avoided. i.g. switch_mm is not needed,
just returns and this makes the I & D caches are valid which shows
great improvement of performance including task switching and IPC.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This is a trivial patch to export flush_dcache_page in mm/nommu.c.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Russell King