This patch adds some generic macros to reduce boilerplate when
declaring certain common structures in arch/arm/mm/*.S
Thanks to Russell King for outlining what the
define_processor_functions macro could look like.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
The l2x0_disable function attempts to writel with the l2x0_lock held.
This results in deadlock when the writel contains an outer_sync call
for the platform since the l2x0_lock is already held by the disable
function. A further problem is that disabling the L2 without flushing it
first can lead to the spin_lock operation becoming visible after the
spin_unlock, causing any subsequent L2 maintenance to deadlock.
This patch replaces the writel with a call to writel_relaxed in the
disabling code and adds a flush before disabling in the control
register, preventing livelock from occurring.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Ensure that the meminfo array is sanity checked before we pass the
memory to memblock. This helps to ensure that memblock and meminfo
agree on the dimensions of memory, especially when more memory is
passed than the kernel can deal with.
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Now that we pass r2 into these helper functions as the pointer to
pt_regs, use r2 as the base of the registers on the stack rather
than using the stack pointer directly.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tail-call the main C data abort handler code from the per-CPU helper
code. Update the comments in the code wrt the new calling and return
register state.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This allows us to pass the pt_regs pointer in to these functions
ready for tail-calling the abort handler.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tail-call the main C prefetch abort handler code from the per-CPU
helper code. Also note that the helper function becomes ABI
compliant in terms of the registers preserved.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Avoid enabling interrupts if the parent context had interrupts enabled
in the abort handler assembly code, and move this into the breakpoint/
page/alignment fault handlers instead.
This gets rid of some special-casing for the breakpoint fault handlers
from the low level abort handler path.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.
For the various event classes:
- hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
the PMI-tail (ARM etc.)
- tracepoint: nmi=0; since tracepoint could be from NMI context.
- software: nmi=[0,1]; some, like the schedule thing cannot
perform wakeups, and hence need 0.
As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).
The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This avoids unnecessary instructions for CPUs which implement the IFAR
(instruction fault address register).
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We can test bits 27:25 and 20 of the instruction at the same time;
there's no need to separate out the check of bit 20.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Require all callers of abort macros to specify the registers to be
used. This improves the documentation at the callsites as to which
registers are being used by this assembly code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
cpu_proc_init() does processor specific initialization, which we do
at boot time. We have been omitting to do this on resume, which
causes some of this initialization to be skipped. We've also been
skipping this on SMP initialization too.
Ensure that cpu_proc_init() is always called appropriately by
moving it into cpu_init(), and move cpu_init() to a more appropriate
point in the boot initialization.
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Ensure that the TLS register is saved and restored over a suspend
cycle, so that userspace programs don't see a corrupted TLS value.
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add the missing suspend/resume pointers for the suspend code. This
is needed when building for multiple CPUs.
Tested-by: Kevin Hilman <khilman@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The 1st board support is minimal to get a system up and running
on the Xilinx platform.
This platform reuses the clock implementation from plat-versatile, and
it depends entirely on CONFIG_OF support. There is only one board
support file which obtains all device information from a device tree
dtb file which is passed to the kernel at boot time.
Signed-off-by: John Linn <john.linn@xilinx.com>
We can't cope with initrds outside of memory, so check that the
initrd is within some declared memory to the kernel before using
it. Otherwise we're likely to OOPS during boot.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This reverts commit 45b95235b0.
Will Deacon reports that:
In 52af9c6c ("ARM: 6943/1: mm: use TTBR1 instead of reserved context ID")
I updated the ASID rollover code to use only the kernel page tables
whilst updating the ASID.
Unfortunately, the code to restore the user page tables was part of a
later patch which isn't yet in mainline, so this leaves the code
quite broken.
We're also in the process of eliminating __ARCH_WANT_INTERRUPTS_ON_CTXSW
from ARM, so lets revert these until we can properly sort out what we're
doing with the context switching.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This reverts commit 52af9c6cd8.
Will Deacon reports that:
In 52af9c6c ("ARM: 6943/1: mm: use TTBR1 instead of reserved context ID")
I updated the ASID rollover code to use only the kernel page tables
whilst updating the ASID.
Unfortunately, the code to restore the user page tables was part of a
later patch which isn't yet in mainline, so this leaves the code
quite broken.
We're also in the process of eliminating __ARCH_WANT_INTERRUPTS_ON_CTXSW
from ARM, so lets revert these until we can properly sort out what we're
doing with the ARM context switching.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The "Virtual memory kernel layout" message at startup already prints
.text and .data. Print .bss too.
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
gas used to accept (and ignore?) .size directives which referred to
undefined symbols, as these do. In binutils 2.21 these are treated
as fatal errors.
The issue in proc-arm7tdmi.S was also fixed independently by Peter
Chubb.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Now that ASID 0 is no longer used as a reserved value, allow it to be
allocated to tasks.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On ARMv7 CPUs that cache first level page table entries (like the
Cortex-A15), using a reserved ASID while changing the TTBR or flushing
the TLB is unsafe.
This is because the CPU may cache the first level entry as the result of
a speculative memory access while the reserved ASID is assigned. After
the process owning the page tables dies, the memory will be reallocated
and may be written with junk values which can be interpreted as global,
valid PTEs by the processor. This will result in the TLB being populated
with bogus global entries.
This patch avoids the use of a reserved context ID in the v7 switch_mm
and ASID rollover code by temporarily using the swapper_pg_dir pointed
at by TTBR1, which contains only global entries that are not tagged
with ASIDs.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch makes TTBR1 point to swapper_pg_dir so that global, kernel
mappings can be used exclusively on v6 and v7 cores where they are
needed.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The v6 and v7 implementations of flush_kern_dcache_area do not align
the passed MVA to the size of a cacheline in the data cache. If a
misaligned address is used, only a subset of the requested area will
be flushed. This has been observed to cause failures in SMP boot where
the secondary_data initialised by the primary CPU is not cacheline
aligned, causing the secondary CPUs to read incorrect values for their
pgd and stack pointers.
This patch ensures that the base address is cacheline aligned before
flushing the d-cache.
Cc: <stable@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
sanity_check_meminfo walks over the registered memory banks and attempts
to split banks across lowmem and highmem when they would otherwise
overlap with the vmalloc space.
When SPARSEMEM is used, there are two potential problems that occur
when the virtual address of the start of a bank is equal to vmalloc_min.
1.) The end of lowmem is calculated as __pa(vmalloc_min - 1) + 1.
In the above scenario, this will give the end address of the
previous bank, rather than the actual bank we are interested in.
This value is later used as the memblock limit and artificially
restricts the total amount of available memory.
2.) The checks to determine whether or not a bank belongs to highmem
or not only check if __va(bank->start) is greater or less than
vmalloc_min. In the case that it is equal, the bank is incorrectly
treated as lowmem, which hoses the vmalloc area.
This patch fixes these two problems by checking whether the virtual
start address of a bank is >= vmalloc_min and then calculating
lowmem_end by finding the virtual end address of the highest lowmem
bank.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In commit eb33575c ("[ARM] Double check memmap is actually valid with a
memmap has unexpected holes V2"), a new function, memmap_valid_within,
was introduced to mmzone.h so that holes in the memmap which pass
pfn_valid in SPARSEMEM configurations can be detected and avoided.
The fix to this problem checks that the pfn <-> page linkages are
correct by calculating the page for the pfn and then checking that
page_to_pfn on that page returns the original pfn. Unfortunately, in
SPARSEMEM configurations, this results in reading from the page flags to
determine the correct section. Since the memmap here has been freed,
junk is read from memory and the check is no longer robust.
In the best case, reading from /proc/pagetypeinfo will give you the
wrong answer. In the worst case, you get SEGVs, Kernel OOPses and hung
CPUs. Furthermore, ioremap implementations that use pfn_valid to
disallow the remapping of normal memory will break.
This patch allows architectures to provide their own pfn_valid function
instead of using the default implementation used by sparsemem. The
architecture-specific version is aware of the memmap state and will
return false when passed a pfn for a freed page within a valid section.
Acked-by: Mel Gorman <mgorman@suse.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fold all the mmu_gather rework patches into one for submission
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Hugh Dickins <hughd@google.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Miller <davem@davemloft.net>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Tony Luck <tony.luck@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Namhyung Kim <namhyung@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Architectures that implement their own show_mem() function did not pass
the filter argument to show_free_areas() to appropriately avoid emitting
the state of nodes that are disallowed in the current context. This patch
now passes the filter argument to show_free_areas() so those nodes are now
avoided.
This patch also removes the show_free_areas() wrapper around
__show_free_areas() and converts existing callers to pass an empty filter.
ia64 emits additional information for each node, so skip_free_areas_zone()
must be made global to filter disallowed nodes and it is converted to use
a nid argument rather than a zone for this use case.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: James Bottomley <jejb@parisc-linux.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If a dtb is passed to the kernel then the kernel needs to iterate
through compiled-in mdescs looking for one that matches and move the
dtb data to a safe location before it gets accidentally overwritten by
the kernel.
This patch creates a new function, setup_machine_fdt() which is
analogous to the setup_machine_atags() created in the previous patch.
It does all the early setup needed to use a device tree machine
description.
v5: - Print warning with neither dtb nor atags are passed to the kernel
- Fix bug in setting of __machine_arch_type to the selected machine,
not just the last machine in the list.
Reported-by: Tixy <tixy@yxit.co.uk>
- Copy command line directly into boot_command_line instead of cmd_line
v4: - Dump some output when a matching machine_desc cannot be found
v3: - Added processing of reserved list.
- Backed out the v2 change that copied instead of reserved the
dtb. dtb is reserved again and the real problem was fixed by
using alloc_bootmem_align() for early allocation of RAM for
unflattening the tree.
- Moved cmd_line and initrd changes to earlier patch to make series
bisectable.
v2: Changed to save the dtb by copying into an allocated buffer.
- Since the dtb will very likely be passed in the first 16k of ram
where the interrupt vectors live, memblock_reserve() is
insufficient to protect the dtb data.
[based on work originally written by Jeremy Kerr <jeremy.kerr@canonical.com>]
Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
when cache_is_vipt_nonaliasing(), we always have pte_exec() true at
the end of this function, so no need for the additional check.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Saeed Bishara <saeed@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The SPARSEMEM code allocates memmap entries only for sections which are
present (i.e. those which contain some valid memory). The membank checks
in free_unused_memmap do not take this into account and can incorrectly
attempt to free memory which is not allocated, resulting in a BUG() in
the bootmem code.
However, if memory is configured as follows:
|<----section---->|<----hole---->|<----section---->|
+--------+--------+--------------+--------+--------+
| bank 0 | unused | | bank 1 | unused |
+--------+--------+--------------+--------+--------+
where a bank only occupies part of a section, the memmap allocated for
the remainder of the section *can* be freed.
This patch modifies the checks in free_unused_memmap so that only valid
memmap entries are considered for removal.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than each platform providing its own function to adjust the
zone sizes, use the new ARM_DMA_ZONE_SIZE definition to perform this
adjustment. This ensures that the actual DMA zone size and the
ISA_DMA_THRESHOLD/MAX_DMA_ADDRESS definitions are consistent with
each other, and moves this complexity out of the platform code.
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add some basic empty infrastructure for DT support on ARM.
v5: - Fix off-by-one error in size calculation of initrd
- Stop mucking with cmd_line, and load command line from dt into
boot_command_line instead which matches the behaviour of ATAGS booting
v3: - moved cmd_line export and initrd setup to this patch to make the
series bisectable.
- switched to alloc_bootmem_align() for allocation when
unflattening the device tree. memblock_alloc() was not the
right interface.
Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
The Marvell PJ4 is ARMv7 capable, so we don't support it in
ARMv6 mode anymore.
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Acked-by: Saeed Bishara <saeed.bishara@gmail.com>
Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com>
gas used to accept (and ignore?) .size directives which referred to
undefined symbols, as this does. In binutils 2.21 these are treated
as fatal errors.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
CONFIG_PM is now set whenever we support either runtime PM in addition
to suspend and hibernate. This causes build errors when runtime PM is
enabled on a platform, but the CPU does not have the appropriate support
for suspend.
So, switch this code to use CONFIG_PM_SLEEP rather than CONFIG_PM to
allow runtime PM to be enabled without causing build errors.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit ddd588b5dd ("oom: suppress nodes that are not allowed from
meminfo on oom kill") moved lib/show_mem.o out of lib/lib.a, which
resulted in build warnings on all architectures that implement their own
versions of show_mem():
lib/lib.a(show_mem.o): In function `show_mem':
show_mem.c:(.text+0x1f4): multiple definition of `show_mem'
arch/sparc/mm/built-in.o:(.text+0xd70): first defined here
The fix is to remove __show_mem() and add its argument to show_mem() in
all implementations to prevent this breakage.
Architectures that implement their own show_mem() actually don't do
anything with the argument yet, but they could be made to filter nodes
that aren't allowed in the current context in the future just like the
generic implementation.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: James Bottomley <James.Bottomley@hansenpartnership.com>
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (35 commits)
ARM: Update (and cut down) mach-types
ARM: 6771/1: vexpress: add support for multiple core tiles
ARM: 6797/1: hw_breakpoint: Fix newlines in WARNings
ARM: 6751/1: vexpress: select applicable errata workarounds in Kconfig
ARM: 6753/1: omap4: Enable ARM local timers with OMAP4430 es1.0 exception
ARM: 6759/1: smp: Select local timers vs broadcast timer support runtime
ARM: pgtable: add pud-level code
ARM: 6673/1: LPAE: use phys_addr_t instead of unsigned long for start of membanks
ARM: Use long long format when printing meminfo physical addresses
ARM: integrator: add Integrator/CP sched_clock support
ARM: realview/vexpress: consolidate SMP bringup code
ARM: realview/vexpress: consolidate localtimer support
ARM: integrator/versatile: consolidate FPGA IRQ handling code
ARM: rationalize versatile family Kconfig/Makefile
ARM: realview: remove old AMBA device DMA definitions
ARM: versatile: remove old AMBA device DMA definitions
ARM: vexpress: use new init_early for clock tree and sched_clock init
ARM: realview: use new init_early for clock tree and sched_clock init
ARM: versatile: use new init_early for clock tree and sched_clock init
ARM: integrator: use new init_early for clock tree init
...
* 'devel-stable' of master.kernel.org:/home/rmk/linux-2.6-arm: (289 commits)
davinci: DM644x EVM: register MUSB device earlier
davinci: add spi devices on tnetv107x evm
davinci: add ssp config for tnetv107x evm board
davinci: add tnetv107x ssp platform device
spi: add ti-ssp spi master driver
mfd: add driver for sequencer serial port
ARM: EXYNOS4: Implement Clock gating for System MMU
ARM: EXYNOS4: Enhancement of System MMU driver
ARM: EXYNOS4: Add support for gpio interrupts
ARM: S5P: Add function to register gpio interrupt bank data
ARM: S5P: Cleanup S5P gpio interrupt code
ARM: EXYNOS4: Add missing GPYx banks
ARM: S3C64XX: Fix section mismatch from cpufreq init
ARM: EXYNOS4: Add keypad device to the SMDKV310
ARM: EXYNOS4: Update clocks for keypad
ARM: EXYNOS4: Update keypad base address
ARM: EXYNOS4: Add keypad device helpers
ARM: EXYNOS4: Add support for SATA on ARMLEX4210
plat-nomadik: make GPIO interrupts work with cpuidle ApSleep
mach-u300: define a dummy filter function for coh901318
...
Fix up various conflicts in
- arch/arm/mach-exynos4/cpufreq.c
- arch/arm/mach-mxs/gpio.c
- drivers/net/Kconfig
- drivers/tty/serial/Kconfig
- drivers/tty/serial/Makefile
- drivers/usb/gadget/fsl_mxc_udc.c
- drivers/video/Kconfig
On the r2p* and r3p* versions of the Cortex-A9, a speculative memory
access may cause a page table walk which starts prior to an ASID switch
but completes afterwards. This can populate the micro-TLB with a stale
entry which may be hit with the new ASID.
This workaround places two dsb instructions in the mm switching code so
that no page table walks can cross the ASID switch.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
PL310 implements the Clean & Invalidate by Way L2 cache maintenance
operation (offset 0x7FC). This operation runs in background so that
PL310 can handle normal accesses while it is in progress. Under very
rare circumstances, due to this erratum, write data can be lost when
PL310 treats a cacheable write transaction during a Clean & Invalidate
by Way operation.
Workaround:
Disable Write-Back and Cache Linefill (Debug Control Register)
Clean & Invalidate by Way (0x7FC)
Re-enable Write-Back and Cache Linefill (Debug Control Register)
This patch also removes any OMAP dependency on PL310 Errata's
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move to SOC_SOC_IMX3X.
Leave ARCH_MX31/35 definitions there, in case some place prevent multi-soc
single image.
Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Move L1_CACHE_SHIFT related options together, rather than spreading them
across two separate Kconfig files.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
In commit e616c59140, highmem support was
deactivated for SMP platforms without hardware TLB ops broadcast because
usage of kmap_high_get() requires that IRQs be disabled when kmap_lock
is locked which is incompatible with the IPI mechanism used by the
software TLB ops broadcast invoked through flush_all_zero_pkmaps().
The reason for kmap_high_get() is to ensure that the currently kmap'd
page usage count does not decrease to zero while we're using its
existing virtual mapping in an atomic context. With a VIVT cache this
is essential to do due to cache coherency issues, but with a VIPT cache
this is only an optimization so not to pay the price of establishing a
second mapping if an existing one can be used. However, on VIPT
platforms without hardware TLB maintenance we can give up on that
optimization in order to be able to use highmem.
From ARMv7 onwards the TLB ops are broadcasted in hardware, so let's
disable ARCH_NEEDS_KMAP_HIGH_GET only when CONFIG_SMP and
CONFIG_CPU_TLB_V6 are defined.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Saeed Bishara <saeed.bishara@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Achieve better usage of the DMA coherent region by doing top-down
allocation rather than bottom up. If we ask for a 128kB allocation,
this will be aligned to 128kB and satisfied from the very bottom
address. If we then ask for a 600kB allocation, this will be aligned
to 1MB, and we will have a 896kB hole.
Performing top-down allocation resolves this by allocating the 128kB
at the very top, and then the 600kB can come in below it without any
unnecessary wastage.
This problem was reported by Janusz Krzysztofik, who had 2 x 128kB +
1 x 640kB allocations which wouldn't fit into 1MB.
Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This adds core support for saving and restoring CPU coprocessor
registers for suspend/resume support. This contains support for suspend
with ARM920, ARM926, SA11x0, PXA25x, PXA27x, PXA3xx, V6 and V7 CPUs.
Tested on Assabet and Tegra 2.
Tested-by: Colin Cross <ccross@android.com>
Tested-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch changes the Kconfig and Makefile for the new ARCH_EXYNOS4.
It also updates arch/arm/Kconfig, Makeifile and arch/arm/mm/Kconfig
to include support for the new ARCH_EXYNOS4.
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Add pud_offset() et.al. between the pgd and pmd code in preparation of
using pgtable-nopud.h rather than 4level-fixup.h.
This incorporates a fix from Jamie Iles <jamie@jamieiles.com> for
uaccess_with_memcpy.c.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On versions of the Cortex-A9 prior to r3p0, an interrupted ICIALLUIS
operation may prevent the completion of a following broadcasted
operation if the second operation is received by a CPU before the
ICIALLUIS has completed, potentially leading to corrupted entries in
the cache or TLB.
This workaround sets a bit in the diagnostic register of the Cortex-A9,
causing CP15 maintenance operations to be uninterruptible.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The effect of cache sync operation is to drain the store buffer and
wait for all internal buffers to be empty. In normal conditions, store
buffer is able to merge the normal memory writes within its 32-byte
data buffers. Due to this erratum present in r3p0, the effect of cache
sync operation on the store buffer still remains when the operation
completes. This means that the store buffer is always asked to drain
and this prevents it from merging any further writes.
This can severely affect performance on the write traffic esp. on
Normal memory NC one.
The proposed workaround is to replace the normal offset of cache sync
operation(0x730) by another offset targeting an unmapped PL310
register 0x740.
Signed-off-by: srinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The unsigned long datatype is not sufficient for mapping physical addresses
>= 4GB.
This patch ensures that the phys_addr_t datatype is used to represent physical
addresses when converting from a PFN.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
For the Kernel to support 2 level and 3 level page tables, physical
addresses (and also page table entries) need to be 32 or 64-bits depending
upon the configuration.
This patch uses the %08llx conversion specifier for physical addresses
and page table entries, ensuring that they are cast to (long long) so
that common code can be used regardless of the datatype widths.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
With LPAE we no longer have software bits in a separate Linux PTE and
the early_pte_alloc() function should pass PTE_HWTABLE_OFF +
PTE_HWTABLE_SIZE to early_alloc() to avoid allocating extra memory.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
SWP emulation requires that CPU domain support is disabled in order to
work safely. Make that explicit in the kernel configuration to prevent
illegal configurations being generated.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
OMAP2 (armv6) and MX3 turn off support for the V6K instructions, which
when they include support for SMP kernels means that the resulting
kernel is unsafe on SMP and can result in corrupted filesystems as we
end up using unsafe bitops.
Re-enable the use of V6K instructions on such kernels, and let such
kernels running on V6 CPUs eat undefined instruction faults which will
be much safer than filesystem corruption. Next merge window we can fix
this properly (as it requires a much bigger set of changes.)
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Limit DMA_CACHE_RWFO to only v6k SMP CPUs - V6 CPUs aren't SMP capable,
so the read/write for ownership work-around doesn't apply to them.
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Now that we build a v6+v6k+v7 kernel with -march=armv6k for everything,
we don't need to disable swp emulation to work around the build problem
with OMAP.
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
CPU_32v6K controls whether we use the ARMv6K extension instructions in
the kernel, and in some places whether we use SMP-safe code sequences
(eg, bitops.)
MX3 prevents the selection of this option to ensure that it is not
enabled for their CPU, which is ARMv6 only. Now that we've split the
CPU_V6 option, V6K support won't be offered for MX3 anymore.
OMAP prevents the selection of this option in an attempt to produce a
kernel which runs on architectures from ARMv6 to ARMv7 MPCore. We now
achieve this in a different way (see the previous patches).
As such, we no longer need to offer this as a configuration option to
the user.
Tested-by: Tony Lindgren <tony@atomide.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Rather than turning off CPU domain switching when the build architecture
includes ARMv6K, thereby causing problems for ARMv6-supporting kernels,
turn it on when it's required to support a CPU architecture.
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If CONFIG_CPU_V6 is enabled, then the kernel must support ARMv6 CPUs
which don't have the V6K extensions implemented. Always use the
dummy store-exclusive method to ensure that the exclusive monitors are
cleared.
If CONFIG_CPU_V6 is not set, but CONFIG_CPU_32v6K is enabled, then we
have the K extensions available on all CPUs we're building support for,
so we can use the new clear-exclusive instruction.
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Make Dove platforms select the new V6K CPU option.
Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Introduce a CPU_V6K configuration option for platforms to select if they
have a V6K CPU core. This allows us to identify whether we need to
support ARMv6 CPUs without the V6K SMP extensions at build time.
Currently CPU_V6K is just an alias for CPU_V6, and all places which
reference CPU_V6 are replaced by (CPU_V6 || CPU_V6K).
Select CPU_V6K from platforms which are known to be V6K-only.
Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Disable the initrd if the passed address already overlaps the reserved
region. This avoids oopses on Netwinders when NeTTrom tells the kernel
that an initrd is located at mem+4MB, but this overlaps the BSS,
resulting in the kernels in-use BSS being freed.
This should be applied to v2.6.37-stable.
Cc: <stable@kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'fixes' of master.kernel.org:/home/rmk/linux-2.6-arm:
ARM: fix missing branch in __error_a
ARM: fix /proc/$PID/stack on SMP
ARM: Fix build regression on SA11x0, PXA, and H720x targets
ARM: 6625/1: use memblock memory regions for "System RAM" I/O resources
ARM: fix wrongly patched constants
ARM: 6624/1: fix dependency for CONFIG_SMP_ON_UP
ARM: 6623/1: Thumb-2: Fix out-of-range offset for Thumb-2 in proc-v7.S
ARM: 6622/1: fix dma_unmap_sg() documentation
ARM: 6621/1: bitops: remove condition code clobber for CLZ
ARM: 6620/1: Change misleading warning when CONFIG_CMDLINE_FORCE is used
ARM: 6619/1: nommu: avoid mapping vectors page when !CONFIG_MMU
ARM: sched_clock: make minsec argument to clocks_calc_mult_shift() zero
ARM: sched_clock: allow init_sched_clock() to be called early
ARM: integrator: fix compile warning in cpu.c
ARM: 6616/1: Fix ep93xx-fb init/exit annotations
ARM: twd: fix display of twd frequency
ARM: udelay: prevent math rounding resulting in short udelays
* 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6: (27 commits)
omap4: Fix ULPI PHY init for ES1.0 SDP
omap3: beaglexm: fix power on of DVI
omap3: igep3: Add omap_reserve functionality
omap3: beaglexm: fix DVI reset GPIO
omap3: beaglexm: fix EHCI power up GPIO dir
omap3: igep2: Add keypad support
omap3: igep3: Fix IGEP module second MMC channel power supply
omap3: igep3: Add USB EHCI support for IGEP module
omap3: clocks: Fix build error 'CK_3430ES2' undeclared here
arm: omap4: pandaboard: turn on PHY reference clock at init
omap2plus: prm: Trvial build break fix for undefined reference to 'omap2_prm_read_mod_reg'
omap2plus: voltage: Trivial linking fix for 'EINVAL' undeclared
omap2plus: voltage: Trivial linking fix 'undefined reference'
omap2plus: voltage: Trivial warning fix 'no return statement'
omap2plus: clockdomain: Trivial fix for build break because of clktrctrl_mask
arm: omap: gpio: don't access irq_desc array directly
omap2+: pm_bus: make functions used as pointers as static
OMAP: GPIO: fix _set_gpio_triggering() for OMAP2+
OMAP2+: TWL: include pm header for init protos
OMAP2+: TWL: make conversion routines static
...
Fix up conflicts in arch/arm/mach-omap2/board-omap3beagle.c ("DVI reset
GPIO" vs "use generic DPI panel driver")
Commit d30e45e (ARM: pgtable: switch order of Linux vs hardware page tables)
introduced a pre-increment addressing offset which is out of range for
Thumb-2. Thumb-2 only permits offsets <256. So split the intruction in
two for Thumb-2.
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
pte alloc routines must wait for split_huge_page if the pmd is not present
and not null (i.e. pmd_trans_splitting). The additional branches are
optimized away at compile time by pmd_trans_splitting if the config option
is off. However we must pass the vma down in order to know the anon_vma
lock to wait for.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The kerneldoc for this function is at odds with the DMA-API
document, which holds, so fix it.
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This option uses LDREXB/STREXB to emulate SWPB but these instructions
are not supported on all the ARMv6 processors.
Reported-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Leif Lindholm <Leif.Lindholm@arm.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Add ARM support for the DMA debug infrastructure, which allows the
DMA API usage to be debugged.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Replace the page_to_dma() and dma_to_page() macros with their PFN
equivalents. This allows us to map parts of memory which do not have
a struct page allocated to them to bus addresses. This will be used
internally by dma_alloc_coherent()/dma_alloc_writecombine().
Build tested on Versatile, OMAP1, IOP13xx and KS8695.
Tested-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Conflicts:
MAINTAINERS
arch/arm/mach-omap2/pm24xx.c
drivers/scsi/bfa/bfa_fcpim.c
Needed to update to apply fixes for which the old branch was too
outdated.
The hardware page tables use an XN bit 'execute never'. Historically,
we've had a Linux 'execute allow' bit, in the positive sense. Get rid
of this artifact as future hardware will continue to have the XN sense.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
FIRST_USER_PGD_NR is now unnecessary, as this has been replaced by
FIRST_USER_ADDRESS except in the architecture code. Fix up the last
usage of FIRST_USER_PGD_NR, and remove the definition.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Remove some knowledge of our 2-level page table layout from the
identity mapping code - we assume that a step size of PGDIR_SIZE will
allow us to step over all entries. While this is true today, it won't
be true in the near future.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We have two places where we create identity mappings - one when we bring
secondary CPUs online, and one where we setup some mappings for soft-
reboot. Combine these two into a single implementation. Also collect
the identity mapping deletion function.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This switches the ordering of the Linux vs hardware page tables in
each page, thereby eliminating some of the arithmetic in the page
table walks. As we now place the Linux page table at the beginning
of the page, we can deal with the offset in the pgt by simply masking
it away, along with the other control bits.
This also makes the arithmetic all be positive, rather than a mixture.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Since commit 3e4d3af501 "mm: stack based kmap_atomic()", it is actively
wrong to rely on fixed kmap type indices (namely KM_L2_CACHE) as
kmap_atomic() totally ignores them and a concurrent instance of it may
happily reuse any slot for any purpose. Because kmap_atomic() is now
able to deal with reentrancy, we can get rid of the ad hoc mapping here.
While the code is made much simpler, there is a needless cache flush
introduced by the usage of __kunmap_atomic(). It is not clear if the
performance difference to remove that is worth the cost in code
maintenance (I don't think there are that many highmem users on that
platform anyway) but that should be reconsidered when/if someone cares
enough to do some measurements.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Since commit 3e4d3af501 "mm: stack based kmap_atomic()", it is actively
wrong to rely on fixed kmap type indices (namely KM_L2_CACHE) as
kmap_atomic() totally ignores them and a concurrent instance of it may
happily reuse any slot for any purpose. Because kmap_atomic() is now
able to deal with reentrancy, we can get rid of the ad hoc mapping here,
and we even don't have to disable IRQs anymore (highmem case).
While the code is made much simpler, there is a needless cache flush
introduced by the usage of __kunmap_atomic(). It is not clear if the
performance difference to remove that is worth the cost in code
maintenance (I don't think there are that many highmem users on that
platform if at all anyway).
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Since commit 3e4d3af501 "mm: stack based kmap_atomic()", it is no longer
necessary to carry an ad hoc version of kmap_atomic() added in commit
7e5a69e83b "ARM: 6007/1: fix highmem with VIPT cache and DMA" to cope
with reentrancy.
In fact, it is now actively wrong to rely on fixed kmap type indices
(namely KM_L1_CACHE) as kmap_atomic() totally ignores them now and a
concurrent instance of it may reuse any slot for any purpose.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Since CPU_PJ4 is shared between PXA95x and MMP2, select CPU_PJ4 in MMP2
configuration.
Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
The core of PXA955 is PJ4. Add new PJ4 support. And add new macro
CONFIG_PXA95x.
Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
Cache ownership must be acquired by reading/writing data from the
cache line to make cache operation have the desired effect on the
SMP MPCore CPU. However, the ownership is never acquired in the
v6_dma_inv_range function when cleaning the first line and
flushing the last one, in case the address is not aligned
to D_CACHE_LINE_SIZE boundary.
Fix this by reading/writing data if needed, before performing
cache operations.
While at it, fix v6_dma_flush_range to prevent RWFO outside
the buffer.
Cc: stable@kernel.org
Signed-off-by: Valentine Barshak <vbarshak@mvista.com>
Signed-off-by: George G. Davis <gdavis@mvista.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The current implementation of the v7_coherent_*_range function assumes
that the D and I cache lines have the same size, which is incorrect
architecturally. This patch adds the icache_line_size macro which reads
the CTR register. The main loop in v7_coherent_*_range is split in two
independent loops or the D and I caches. This also has the performance
advantage that the DSB is moved outside the main loop.
Reported-by: Kevin Sapp <ksapp@quicinc.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The current implementation of the dcache_line_size macro reads the L1
cache size from the CCSIDR register. This, however, is not guaranteed to
be the smallest cache line in the cache hierarchy. The patch changes to
the macro to use the more architecturally correct CTR register.
Reported-by: Kevin Sapp <ksapp@quicinc.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Directives such as .long and .word do not magically cause the
assembler location counter to become aligned in gas. As a result,
using these directives in code sections can result in misaligned
data words when building a Thumb-2 kernel (CONFIG_THUMB2_KERNEL).
This is a Bad Thing, since the ABI permits the compiler to assume
that fundamental types of word size or above are word- aligned when
accessing them from C. If the data is not really word-aligned,
this can cause impaired performance and stray alignment faults in
some circumstances.
In general, the following rules should be applied when using data
word declaration directives inside code sections:
* .quad and .double:
.align 3
* .long, .word, .single, .float:
.align (or .align 2)
* .short:
No explicit alignment required, since Thumb-2
instructions are always 2 or 4 bytes in size.
immediately after an instruction.
In this specific case, we can achieve the desired alignment by
forcing a 32-bit branch instruction using the W() macro, since the
assembler location counter is already 32-bit aligned in this case.
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Remove knowledge of the 2-level wrapping in pgd_free(), and use the
pXd_none_or_clear_bad() macros when checking the entries.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Adding KERN_WARNING in the middle of strings now produces those tokens
in the output, rather than accepting the level as was once the case.
Fix this in the one reported case. There might be more...
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds initial support for Renesas SH-Mobile AG5.
At this point the AG5 CPU support is limited to the ARM
core, SCIF serial and a CMT timer together with L2 cache
and the GIC. The AG5EVM board also supports Ethernet.
Future patches will add support for GPIO, INTCS, CPGA
and platform data / driver updates for devices such as
IIC, LCDC, FSI, KEYSC, CEU and SDHI among others.
The code in entry-macro.S will be cleaned up when the
ARM IRQ demux code improvements have been merged.
Depends on the AG5EVM mach-type recently registered but
not yet present in arch/arm/tools/mach-types.
As the AG5EVM board comes with 512MiB memory it is
recommended to turn on HIGHMEM.
Many thanks to Yoshii-san for initial bring up.
Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
It's enough to include the asm/smp_plat.h once in arch/arm/mm/flush.c
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
An out by one bug meant that the DMA coherent allocator was aligning
to one more bit than it should, causing it to run out of available
memory quicker. Fix this.
Reported-by: Petr Štetiar <ynezz@true.cz>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The SWP instruction was deprecated in the ARMv6 architecture,
superseded by the LDREX/STREX family of instructions for
load-linked/store-conditional operations. The ARMv7 multiprocessing
extensions mandate that SWP/SWPB instructions are treated as undefined
from reset, with the ability to enable them through the System Control
Register SW bit.
This patch adds the alternative solution to emulate the SWP and SWPB
instructions using LDREX/STREX sequences, and log statistics to
/proc/cpu/swp_emulation. To correctly deal with copy-on-write, it also
modifies cpu_v7_set_pte_ext to change the mappings to priviliged RO when
user RO.
Signed-off-by: Leif Lindholm <leif.lindholm@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch removes the domain switching functionality via the set_fs and
__switch_to functions on cores that have a TLS register.
Currently, the ioremap and vmalloc areas share the same level 1 page
tables and therefore have the same domain (DOMAIN_KERNEL). When the
kernel domain is modified from Client to Manager (via the __set_fs or in
the __switch_to function), the XN (eXecute Never) bit is overridden and
newer CPUs can speculatively prefetch the ioremap'ed memory.
Linux performs the kernel domain switching to allow user-specific
functions (copy_to/from_user, get/put_user etc.) to access kernel
memory. In order for these functions to work with the kernel domain set
to Client, the patch modifies the LDRT/STRT and related instructions to
the LDR/STR ones.
The user pages access rights are also modified for kernel read-only
access rather than read/write so that the copy-on-write mechanism still
works. CPU_USE_DOMAINS gets disabled only if the hardware has a TLS register
(CPU_32v6K is defined) since writing the TLS value to the high vectors page
isn't possible.
The user addresses passed to the kernel are checked by the access_ok()
function so that they do not point to the kernel space.
Tested-by: Anton Vorontsov <cbouatmailru@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm: (215 commits)
ARM: memblock: setup lowmem mappings using memblock
ARM: memblock: move meminfo into find_limits directly
ARM: memblock: convert free_highpages() to use memblock
ARM: move freeing of highmem pages out of mem_init()
ARM: memblock: convert memory detail printing to use memblock
ARM: memblock: use memblock to free memory into arm_bootmem_init()
ARM: memblock: use memblock when initializing memory allocators
ARM: ensure membank array is always sorted
ARM: 6466/1: implement flush_icache_all for the rest of the CPUs
ARM: 6464/2: fix spinlock recursion in adjust_pte()
ARM: fix memblock breakage
ARM: 6465/1: Fix data abort accessing proc_info from __lookup_processor_type
ARM: 6460/1: ixp2000: fix type of ixp2000_timer_interrupt
ARM: 6449/1: Fix for compiler warning of uninitialized variable.
ARM: 6445/1: fixup TCM memory types
ARM: imx: Add wake functionality to GPIO
ARM: mx5: Add gpio-keys to mx51 babbage board
ARM: imx: Add gpio-keys to plat-mxc
mx31_3ds: Fix spi registration
mx31_3ds: Fix the logic for detecting the debug board
...
Use memblock information to setup lowmem mappings rather than the
membank array.
This allows platforms to manipulate the memblock information during
initialization to reserve (and remove) memory from the kernel's view
of memory - and thus allowing platforms to setup their own private
mappings for this memory without causing problems with multiple
aliasing mappings:
size = min(size, SZ_2M);
base = memblock_alloc(size, min(align, SZ_2M));
memblock_free(base, size);
memblock_remove(base, size);
This is needed because multiple mappings of regions with differing
attributes (sharability, type, cache) are not permitted with ARMv6
and above.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
bootmem_init() no longer makes several uses of the membank
information, so move this into the one remaining called function
which does use it.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Free the high pages using the memblock memory lists - and more
importantly, exclude any memblock allocations in highmem from the
free'd memory.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This was missing from the noMMU code, so there was the possibility
of things not working as expected if out of order memory information
was passed.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit 81d11955bf ("ARM: 6405/1: Handle __flush_icache_all for
CONFIG_SMP_ON_UP") added a new function to struct cpu_cache_fns:
flush_icache_all(). It also implemented this for v6 and v7 but not
for v5 and backwards. Without the function pointer in place, we
will be calling wrong cache functions.
For example with ep93xx we get following:
Unable to handle kernel paging request at virtual address ee070f38
pgd = c0004000
[ee070f38] *pgd=00000000
Internal error: Oops: 80000005 [#1] PREEMPT
last sysfs file:
Modules linked in:
CPU: 0 Not tainted (2.6.36+ #1)
PC is at 0xee070f38
LR is at __dma_alloc+0x11c/0x2d0
pc : [<ee070f38>] lr : [<c0032c8c>] psr: 60000013
sp : c581bde0 ip : 00000000 fp : c0472000
r10: c0472000 r9 : 000000d0 r8 : 00020000
r7 : 0001ffff r6 : 00000000 r5 : c0472400 r4 : c5980000
r3 : c03ab7e0 r2 : 00000000 r1 : c59a0000 r0 : c5980000
Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment kernel
Control: c000717f Table: c0004000 DAC: 00000017
Process swapper (pid: 1, stack limit = 0xc581a270)
[<c0032c8c>] (__dma_alloc+0x11c/0x2d0)
[<c0032e5c>] (dma_alloc_writecombine+0x1c/0x24)
[<c0204148>] (ep93xx_pcm_preallocate_dma_buffer+0x44/0x60)
[<c02041c0>] (ep93xx_pcm_new+0x5c/0x88)
[<c01ff188>] (snd_soc_instantiate_cards+0x8a8/0xbc0)
[<c01ff59c>] (soc_probe+0xfc/0x134)
[<c01adafc>] (platform_drv_probe+0x18/0x1c)
[<c01acca4>] (driver_probe_device+0xb0/0x16c)
[<c01ac284>] (bus_for_each_drv+0x48/0x84)
[<c01ace90>] (device_attach+0x50/0x68)
[<c01ac0f8>] (bus_probe_device+0x24/0x44)
[<c01aad7c>] (device_add+0x2fc/0x44c)
[<c01adfa8>] (platform_device_add+0x104/0x15c)
[<c0015eb8>] (simone_init+0x60/0x94)
[<c0021410>] (do_one_initcall+0xd0/0x1a4)
__dma_alloc() calls (inlined) __dma_alloc_buffer() which ends up
calling dmac_flush_range(). Now since the entries in the
arm920_cache_fns are shifted by one, we jump into address 0xee070f38
which is actually next instruction after the arm920_cache_fns
structure.
So implement flush_icache_all() for the rest of the supported CPUs
using a generic 'invalidate I cache' instruction.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When running following code in a machine which has VIVT caches and
USE_SPLIT_PTLOCKS is not defined:
fd = open("/etc/passwd", O_RDONLY);
addr = mmap(NULL, 4096, PROT_READ, MAP_SHARED, fd, 0);
addr2 = mmap(NULL, 4096, PROT_READ, MAP_SHARED, fd, 0);
v = *((int *)addr);
we will hang in spinlock recursion in the page fault handler:
BUG: spinlock recursion on CPU#0, mmap_test/717
lock: c5e295d8, .magic: dead4ead, .owner: mmap_test/717,
.owner_cpu: 0
[<c0026604>] (unwind_backtrace+0x0/0xec)
[<c014ee48>] (do_raw_spin_lock+0x40/0x140)
[<c0027f68>] (update_mmu_cache+0x208/0x250)
[<c0079db4>] (__do_fault+0x320/0x3ec)
[<c007af7c>] (handle_mm_fault+0x2f0/0x6d8)
[<c0027834>] (do_page_fault+0xdc/0x1cc)
[<c00202d0>] (do_DataAbort+0x34/0x94)
This comes from the fact that when USE_SPLIT_PTLOCKS is not defined,
the only lock protecting the page tables is mm->page_table_lock
which is already locked before update_mmu_cache() is called.
Signed-off-by: Mika Westerberg <mika.westerberg@iki.fi>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Christoph reported a nice splat which illustrated a race in the new stack
based kmap_atomic implementation.
The problem is that we pop our stack slot before we're completely done
resetting its state -- in particular clearing the PTE (sometimes that's
CONFIG_DEBUG_HIGHMEM). If an interrupt happens before we actually clear
the PTE used for the last slot, that interrupt can reuse the slot in a
dirty state, which triggers a BUG in kmap_atomic().
Fix this by introducing kmap_atomic_idx() which reports the current slot
index without actually releasing it and use that to find the PTE and delay
the _pop() until after we're completely done.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reported-by: Christoph Hellwig <hch@infradead.org>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Will says:
| Commit e63075a3 removed the explicit MEMBLOCK_REAL_LIMIT #define
| and introduced the requirement that arch code calls
| memblock_set_current_limit to ensure that the __va macro can
| be used on physical addresses returned from memblock_alloc.
Unfortunately, ARM was missed out of this change. Fix this.
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
After Santosh's fixup of the generic MT_MEMORY and
MT_MEMORY_NONCACHED I add this fix to the TCM memory types.
The main change is that the ITCM memory is L_PTE_WRITE and
DOMAIN_KERNEL which works just fine. The changed to the DTCM
is just cosmetic to fit with surrounding code.
Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Rickard Andersson <rickard.andersson@stericsson.com>
Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Since we no longer need to provide KM_type, the whole pte_*map_nested()
API is now redundant, remove it.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Keep the current interface but ignore the KM_type and use a stack based
approach.
The advantage is that we get rid of crappy code like:
#define __KM_PTE \
(in_nmi() ? KM_NMI_PTE : \
in_irq() ? KM_IRQ_PTE : \
KM_PTE0)
and in general can stop worrying about what context we're in and what kmap
slots might be appropriate for that.
The downside is that FRV kmap_atomic() gets more expensive.
For now we use a CPP trick suggested by Andrew:
#define kmap_atomic(page, args...) __kmap_atomic(page)
to avoid having to touch all kmap_atomic() users in a single patch.
[ not compiled on:
- mn10300: the arch doesn't actually build with highmem to begin with ]
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix up drivers/gpu/drm/i915/intel_overlay.c]
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Miller <davem@davemloft.net>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For the big buffers which are in excess of cache size, the maintaince
operations by PA are very slow. For such buffers the maintainace
operations can be speeded up by using the WAY based method.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
The cache size is needed for to optimise range based
maintainance operations
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Add flush_all, inv_all and disable functions to the l2x0 code. These
functions are called from kexec code to prevent random crashes in the
new kernel.
Platforms like OMAP which control L2 enable/disable via SMI mode can
override the outer_cache.disable() function to implement their own.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
With this L2 cache controller, the cache maintenance by PA and sync
operations are atomic and do not require a "wait" loop. This patch
conditionally defines the cache_wait() function.
Since L2x0 cache controllers do not work with ARMv7 CPUs, the patch
automatically enables CACHE_PL310 when only CPU_V7 is defined.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* 'core-memblock-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (74 commits)
x86-64: Only set max_pfn_mapped to 512 MiB if we enter via head_64.S
xen: Cope with unmapped pages when initializing kernel pagetable
memblock, bootmem: Round pfn properly for memory and reserved regions
memblock: Annotate memblock functions with __init_memblock
memblock: Allow memblock_init to be called early
memblock/arm: Fix memblock_region_is_memory() typo
x86, memblock: Remove __memblock_x86_find_in_range_size()
memblock: Fix wraparound in find_region()
x86-32, memblock: Make add_highpages honor early reserved ranges
x86, memblock: Fix crashkernel allocation
arm, memblock: Fix the sparsemem build
memblock: Fix section mismatch warnings
powerpc, memblock: Fix memblock API change fallout
memblock, microblaze: Fix memblock API change fallout
x86: Remove old bootmem code
x86, memblock: Use memblock_memory_size()/memblock_free_memory_size() to get correct dma_reserve
x86: Remove not used early_res code
x86, memblock: Replace e820_/_early string with memblock_
x86: Use memblock to replace early_res
x86, memblock: Use memblock_debug to control debug message print out
...
Fix up trivial conflicts in arch/x86/kernel/setup.c and kernel/Makefile
... but produce a big warning about the problem as encouragement
for people to fix their drivers.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We need to round memory regions correctly -- specifically, we need to
round reserved region in the more expansive direction (lower limit
down, upper limit up) whereas usable memory regions need to be rounded
in the more restrictive direction (lower limit up, upper limit down).
This introduces two set of inlines:
memblock_region_memory_base_pfn()
memblock_region_memory_end_pfn()
memblock_region_reserved_base_pfn()
memblock_region_reserved_end_pfn()
Although they are antisymmetric (and therefore are technically
duplicates) the use of the different inlines explicitly documents the
programmer's intention.
The lack of proper rounding caused a bug on ARM, which was then found
to also affect other architectures.
Reported-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <4CB4CDFD.4020105@kernel.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
When hotplug CPU is enabled, we need to keep the list of supported CPUs,
their setup functions, and __lookup_processor_type in place so that we
can find and initialize secondary CPUs. Move these into the __CPUINIT
section.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit 14eff18126 added proper
detection for ARM11MPCore/Cortex-A9 instead of detecting them
as ARMv7. However, it was missing the HWCAP_TLS flags.
HWCAP_TLS is needed if support for earlier ARMv6 is compiled
into the same kernel. Without HWCAP_TLS flags the userspace
won't work unless nosmp is specified:
Kernel panic - not syncing: Attempted to kill init!
CPU0: stopping
<c005d5e4>] (unwind_backtrace+0x0/0xec) from [<c004c2f8>] (do_IPI+0xfc/0x184)
<c004c2f8>] (do_IPI+0xfc/0x184) from [<c03f25bc>] (__irq_svc+0x9c/0x160)
Exception stack(0xc0565f80 to 0xc0565fc8)
5f80: 00000001 c05772a0 00000000 00003a61 c0564000 c05cf500 c003603c c0578600
5fa0: 80033ef0 410fc091 0000001f 00000000 00000000 c0565fc8 c00b91f8 c0057cb4
5fc0: 20000013 ffffffff
[<c03f25bc>] (__irq_svc+0x9c/0x160) from [<c0057cb4>] (default_idle+0x30/0x38)
[<c0057cb4>] (default_idle+0x30/0x38) from [<c005829c>] (cpu_idle+0x9c/0xf8)
[<c005829c>] (cpu_idle+0x9c/0xf8) from [<c0008d48>] (start_kernel+0x2a4/0x300)
[<c0008d48>] (start_kernel+0x2a4/0x300) from [<80008084>] (0x80008084)
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
copy_to_user_page can be used by access_process_vm to write to an
executable page of a process using a mapping acquired by kmap.
For systems with I-cache aliasing, flushing the I-cache using the
Kernel mapping may leave stale data in the I-cache if the user
mapping is of a different colour.
This patch introduces a flush_icache_alias function to flush.c,
which calls flush_icache_range with a mapping of the specified
colour. flush_ptrace_access is then modified to call this new
function instead of coherent_kern_range in the case of an aliasing
I-cache and a non-aliasing D-cache.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Do this by adding flush_icache_all to cache_fns for ARMv6 and 7.
As flush_icache_all may neeed to be called from flush_kern_cache_all,
add it as the first entry in the cache_fns.
Note that now we can remove the ARM_ERRATA_411920 dependency
to !SMP so it can be selected on UP ARMv6 processors, such
as omap2.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
UP systems do not implement all the instructions that SMP systems have,
so in order to boot a SMP kernel on a UP system, we need to rewrite
parts of the kernel.
Do this using an 'alternatives' scheme, where the kernel code and data
is modified prior to initialization to replace the SMP instructions,
thereby rendering the problematical code ineffectual. We use the linker
to generate a list of 32-bit word locations and their replacement values,
and run through these replacements when we detect a UP system.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The commit f1a2481c0 sets up the default flags for MT_MEMORY and
MT_MEMORY_NONCACHED memory types. L_PTE_USER flag is wrongly
set as default for these entries so remove it. Also adding
the 'L_PTE_WRITE' flag so that these pages become read-write
instead of just being read-only
[this stops them being exposed to userspace, which is the main
concern here --rmk]
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On the r2p0, r2p1 and r2p2 versions of the Cortex-A9, data corruption
can occur under very rare conditions due to a store buffer optimisation.
This workaround sets a bit in the diagnostic register of the Cortex-A9,
disabling the optimisation and preventing the problem from occurring.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There are very few legitimate use cases, if any, for directly accessing
system RAM through /dev/mem. So let's mimic what they do on x86 and
forbid it when CONFIG_STRICT_DEVMEM is turned on.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
This patch populates the L1 entries for MT_MEMORY and MT_MEMORY_NONCACHED
types so that at boot-up, we can map memories outside system memory
at page level granularity
Previously the mapping was limiting to section level, which creates
unnecessary additional mapping for which physical memory may not
present. On the newer ARM with speculation, this is dangerous and can
result in untraceable aborts.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When the policy for user space is to ignore misaligned accesses from user
space, the processor then performs a documented rotation on the accessed
data. This is the result of the access being trapped, and the kernel
disabling the alignment trap before returning to user space again.
In kernel space we always want misaligned accesses to be fixed up. This
is enforced by always re-enabling the alignment trap on every entry into
kernel space from user space. No such re-enabling is performed when an
exception occurs while already in kernel space as the alignment trap is
always supposed to be enabled in that case.
There is however a small race window when a misaligned access in user
space is trapped and the alignment trap disabled, but the CPU didn't
return to user space just yet. Any exception would be entered from kernel
space at that point and the kernel would then execute with the alignment
trap disabled.
Thanks to Maxime Bizon <mbizon@freebox.fr> for providing a test module
that made this issue reproducible.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARMv7 onwards requires that there are no aliases to the same physical
location using different memory types (i.e. Normal vs Strongly Ordered).
Access to SO mappings when the unaligned accesses are handled in
hardware is also Unpredictable (pgprot_noncached() mappings in user
space).
The /dev/mem driver requires uncached mappings with O_SYNC. The patch
implements the phys_mem_access_prot() function which generates Strongly
Ordered memory attributes if !pfn_valid() (independent of O_SYNC) and
Normal Noncacheable (writecombine) if O_SYNC.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARMv7 processors like Cortex-A9 broadcast the cache maintenance
operations in hardware. This patch allows the
flush_dcache_page/update_mmu_cache pair to work in lazy flushing mode
similar to the UP case.
Note that cache flushing on SMP systems now takes place via the
set_pte_at() call (__sync_icache_dcache) and there is no race with other
CPUs executing code from the new PTE before the cache flushing took
place.
Tested-by: Rabin Vincent <rabin.vincent@stericsson.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On SMP systems, there is a small chance of a PTE becoming visible to a
different CPU before the current cache maintenance operations in
update_mmu_cache(). To avoid this, cache maintenance must be handled in
set_pte_at() (similar to IA-64 and PowerPC).
This patch provides a unified VIPT cache handling mechanism and
implements the __sync_icache_dcache() function for ARMv6 onwards
architectures. It is called from set_pte_at() and replaces the
update_mmu_cache(). The latter is still used on VIVT hardware where a
vm_area_struct is required.
Tested-by: Rabin Vincent <rabin.vincent@stericsson.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There are places in Linux where writes to newly allocated page cache
pages happen without a subsequent call to flush_dcache_page() (several
PIO drivers including USB HCD). This patch changes the meaning of
PG_arch_1 to be PG_dcache_clean and always flush the D-cache for a newly
mapped page in update_mmu_cache().
The patch also sets the PG_arch_1 bit in the DMA cache maintenance
function to avoid additional cache flushing in update_mmu_cache().
Tested-by: Rabin Vincent <rabin.vincent@stericsson.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit d73cd42 forced non-lazy cache flushing of highmem pages in
flush_dcache_page(). This isn't needed since __flush_dcache_page()
(called lazily from update_mmu_cache) can handle highmem pages (fixed by
commit 7e5a69e).
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Setting of these bits can cause issues on other SMP SoC's not produced
by ARM.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On the r2p0, r2p1 and r2p2 versions of the Cortex-A9, data corruption
can occur if a shared cache line is replaced on one CPU as another CPU
is accessing it.
This workaround sets two bits in the diagnostic register of the Cortex-A9,
reducing the linefill issuing capabilities of the processor and
avoiding the erroneous behaviour.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
On versions of the Cortex-A9 up to and including r2p2, under rare
circumstances, a DMB instruction between 2 write operations may not
ensure the correct visibility ordering of the 2 writes.
This workaround sets a bit in the diagnostic register of the Cortex-A9,
causing the DMB instruction to behave like a DSB, which functions
correctly on the affected cores.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
