The standard I-cache Invalidate All (ICIALLU) and Branch Predication
Invalidate All (BPIALL) operations are not automatically broadcast to
the other CPUs in an ARMv7 MP system. The patch adds the Inner Shareable
variants, ICIALLUIS and BPIALLIS, if ARMv7 and SMP.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The Snoop Control Unit on the ARM11MPCore hardware does not detect the
cache operations and the dma_cache_maint*() functions may leave stale
cache entries on other CPUs. The solution implemented in this patch
performs a Read or Write For Ownership in the ARMv6 DMA cache
maintenance functions. These LDR/STR instructions change the cache line
state to shared or exclusive so that the cache maintenance operation has
the desired effect.
Tested-by: George G. Davis <gdavis@mvista.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit 7959722 introduced calls to copy_(to|from)_user_page() from
access_process_vm() in mm/nommu.c. The copy_to_user_page() was not
implemented on noMMU ARM.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit 31aa8fd6 introduced the __arm_ioremap_caller() function but the
nommu.c version did not have the _caller suffix.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The show_mem() and mem_init() function are assuming that the page map is
contiguous and calculates the start and end page of a bank using (map +
pfn). This fails with SPARSEMEM where pfn_to_page() must be used.
Tested-by: Will Deacon <Will.Deacon@arm.com>
Tested-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
/tmp/ccJ3ssZW.s: Assembler messages:
/tmp/ccJ3ssZW.s:1952: Error: can't resolve `.text' {.text section} - `.LFB1077'
This is caused because:
.section .data
.section .text
.section .text
.previous
does not return us to the .text section, but the .data section; this
makes use of .previous dangerous if the ordering of previous sections
is not known.
Fix up the other users of .previous; .pushsection and .popsection are
a safer pairing to use than .section and .previous.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When crash happens in interrupt context there is no userspace context.
We always use current->active_mm in those cases.
Signed-off-by: Mika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The VIVT cache of a highmem page is always flushed before the page
is unmapped. This cache flush is explicit through flush_cache_kmaps()
in flush_all_zero_pkmaps(), or through __cpuc_flush_dcache_area() in
kunmap_atomic(). There is also an implicit flush of those highmem pages
that were part of a process that just terminated making those pages free
as the whole VIVT cache has to be flushed on every task switch. Hence
unmapped highmem pages need no cache maintenance in that case.
However unmapped pages may still be cached with a VIPT cache because the
cache is tagged with physical addresses. There is no need for a whole
cache flush during task switching for that reason, and despite the
explicit cache flushes in flush_all_zero_pkmaps() and kunmap_atomic(),
some highmem pages that were mapped in user space end up still cached
even when they become unmapped.
So, we do have to perform cache maintenance on those unmapped highmem
pages in the context of DMA when using a VIPT cache. Unfortunately,
it is not possible to perform that cache maintenance using physical
addresses as all the L1 cache maintenance coprocessor functions accept
virtual addresses only. Therefore we have no choice but to set up a
temporary virtual mapping for that purpose.
And of course the explicit cache flushing when unmapping a highmem page
on a system with a VIPT cache now can go, which should increase
performance.
While at it, because the code in __flush_dcache_page() has to be modified
anyway, let's also make sure the mapped highmem pages are pinned with
kmap_high_get() for the duration of the cache maintenance operation.
Because kunmap() does unmap highmem pages lazily, it was reported by
Gary King <GKing@nvidia.com> that those pages ended up being unmapped
during cache maintenance on SMP causing segmentation faults.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Write combining/cached device mappings are not setting the shared bit,
which could potentially cause problems on SMP systems since the cache
lines won't participate in the cache coherency protocol.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
The mandatory barriers (mb, rmb, wmb) are used even on uniprocessor
systems for things like ordering Normal Non-cacheable memory accesses
with DMA transfer (via Device memory writes). The current implementation
uses dmb() for mb() and friends but this is not sufficient. The DMB only
ensures the relative ordering of the observability of accesses by other
processors or devices acting as masters. In case of DMA transfers
started by writes to device memory, the relative ordering is not ensured
because accesses to slave ports of a device are not considered
observable by the DMB definition.
A DSB is required for the data to reach the main memory (even if mapped
as Normal Non-cacheable) before the device receives the notification to
begin the transfer. Furthermore, some L2 cache controllers (like L2x0 or
PL310) buffer stores to Normal Non-cacheable memory and this would need
to be drained with the outer_sync() function call.
The patch also allows platforms to define their own mandatory barriers
implementation by selecting CONFIG_ARCH_HAS_BARRIERS and providing a
mach/barriers.h file.
Note that the SMP barriers are unchanged (being DMBs as before) since
they are only guaranteed to work with Normal Cacheable memory.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The L2x0 cache controllers need to explicitly drain their write buffer
even for Normal Noncacheable memory accesses.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch introduces the outer_cache_fns.sync function pointer together
with the OUTER_CACHE_SYNC config option that can be used to drain the
write buffer of the outer cache.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add ARM_L1_CACHE_SHIFT_6 to arch/arm/Kconfig to allow CPUs with
L1 cache lines which are 64bytes to indicate this without having to
alter the arch/arm/mm/Kconfig entry each time.
Update the mm Kconfig so that ARM_L1_CACHE_SHIFT default value
uses this and change OMAP3 and S5PC1XX to select ARM_L1_CACHE_SHIFT_6.
Acked-by: Ben Dooks <ben-linux@fluff.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
update_mmu_cache() is called with the page table for the faulted-in
page still mapped. We need to modify the PTE for this page to ensure
coherency with other shared mappings when multiple shared mappings
exist within a MM.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On VIVT ARM, when we have multiple shared mappings of the same file
in the same MM, we need to ensure that we have coherency across all
copies. We do this via make_coherent() by making the pages
uncacheable.
This used to work fine, until we allowed highmem with highpte - we
now have a page table which is mapped as required, and is not available
for modification via update_mmu_cache().
Ralf Beache suggested getting rid of the PTE value passed to
update_mmu_cache():
On MIPS update_mmu_cache() calls __update_tlb() which walks pagetables
to construct a pointer to the pte again. Passing a pte_t * is much
more elegant. Maybe we might even replace the pte argument with the
pte_t?
Ben Herrenschmidt would also like the pte pointer for PowerPC:
Passing the ptep in there is exactly what I want. I want that
-instead- of the PTE value, because I have issue on some ppc cases,
for I$/D$ coherency, where set_pte_at() may decide to mask out the
_PAGE_EXEC.
So, pass in the mapped page table pointer into update_mmu_cache(), and
remove the PTE value, updating all implementations and call sites to
suit.
Includes a fix from Stephen Rothwell:
sparc: fix fallout from update_mmu_cache API change
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Some glibc versions intentionally create lots of alignment faults in
their gconv code, which if not fixed up, results in segfaults during
boot. This can prevent systems booting properly.
There is no clear hard-configurable default for this; the desired
default depends on the nature of the userspace which is going to be
booted.
So, provide a way for the alignment fault handler to be configured via
the kernel command line.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andreas Fenkart <andreas.fenkart@streamunlimited.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Makes it consistent with VMALLOC_START
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andreas Fenkart <andreas.fenkart@streamunlimited.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Adds DMA area to 'virtual memory map' startup message
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andreas Fenkart <andreas.fenkart@streamunlimited.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Code based on parisc and x86_32.
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Andreas Fenkart <andreas.fenkart@streamunlimited.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch implements the work-around for the errata 588369.The secure
API is used to alter L2 debug register because of trust-zone.
This version updated with comments from Russell and Catalin and
generated against 2.6.33-rc6 mainline kernel. Detail
comments can be found:
http://www.spinics.net/lists/linux-omap/msg23431.html
Signed-off-by: Woodruff Richard <r-woodruff2@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds L2 Cache support for OMAP4. External L2 cache
is used in OMAP4
CC: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds the cache maintainance by line helper functions.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Otherwise the kernel built with both CPU_V6 and CPU_V7 will not
boot on omap2.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The current ASID allocation algorithm doesn't ensure the notification
of the other CPUs when the ASID rolls over. This may lead to two
processes using the same ASID (but different generation) or multiple
threads of the same process using different ASIDs.
This patch adds the broadcasting of the ASID rollover event to the
other CPUs. To avoid a race on multiple CPUs modifying "cpu_last_asid"
during the handling of the broadcast, the ASID numbering now starts at
"smp_processor_id() + 1". At rollover, the cpu_last_asid will be set
to NR_CPUS.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The ARM setup code includes its own parser for early params, there's
also one in the generic init code.
This patch removes __early_init (and related code) from
arch/arm/kernel/setup.c, and changes users to the generic early_init
macro instead.
The generic macro takes a char * argument, rather than char **, so we
need to update the parser functions a little.
Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Always creating this directory avoids other users having to jump
through silly hoops when they want to share this directory.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This allows the procfs vmallocinfo file to show who created the ioremap
regions. Note: __builtin_return_address(0) doesn't do what's expected
if its used in an inline function, so we leave __arm_ioremap callers
in such places alone.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARMv6 and ARMv7 CPUs can perform speculative prefetching, which makes
DMA cache coherency handling slightly more interesting. Rather than
being able to rely upon the CPU not accessing the DMA buffer until DMA
has completed, we now must expect that the cache could be loaded with
possibly stale data from the DMA buffer.
Where DMA involves data being transferred to the device, we clean the
cache before handing it over for DMA, otherwise we invalidate the buffer
to get rid of potential writebacks. On DMA Completion, if data was
transferred from the device, we invalidate the buffer to get rid of
any stale speculative prefetches.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
These are now unused, and so can be removed.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
dma_cache_maint_contiguous is now simple enough to live inside
dma_cache_maint_page, so move it there.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
The DMA API has the notion of buffer ownership; make it explicit in the
ARM implementation of this API. This gives us a set of hooks to allow
us to deal with CPU cache issues arising from non-cache coherent DMA.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-By: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-By: Jamie Iles <jamie@jamieiles.com>
The perf events subsystem allows counting of both hardware and
software events. This patch implements the bare minimum for software
performance events.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jamie Iles <jamie.iles@picochip.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We already know the pfn for the page to be modified in make_coherent,
so let's stop recalculating it unnecessarily.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
update_mmu_cache() is called with a page table already mapped. We
call make_coherent(), which then calls adjust_pte() which wants to
map other page tables. This causes kmap_atomic() to BUG() because
the slot its trying to use is already taken.
Since do_adjust_pte() modifies the page tables, we are also missing
any form of locking, so we're risking corrupting the page tables.
Fix this by using pte_offset_map_nested(), and taking the pte page
table lock around do_adjust_pte().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The comments in cacheflush.h should follow what's in
struct cpu_cache_fns. The comments for V6 and V7 are
unnecessary.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The comments in arm_machine_restart() suggest that cpu_proc_fin()
will clean and disable cache and turn off interrupts. This does
not seem to be implemented for proc-v7.S, implement it the same
way as for proc-v6.S.
This also makes kexec work for v7. Note that a related TLB and
branch traget flush patch is also needed to avoid kexec
"crc error".
Note that there are still some issues that seem to be related
to L2 cache being on and causing occasional uncompress "crc error"
with kexec. Anyways, this gets kexec mostly working on V7 for now.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Catalin Marinas