The CPU reset functions disable the MMU and therefore must be executed
with an identity mapping in place.

This patch places the CPU reset functions into the .idmap.text section,
causing the idmap code to include them as part of the identity mapping.
Acked-by: NDave Martin <dave.martin@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

When disabling and re-enabling the MMU, it is necessary to take out an
identity mapping for the code that manipulates the SCTLR in order to
avoid it disappearing from under our feet. This is useful when soft
rebooting and returning from CPU suspend.

This patch allocates a set of page tables during boot and populates them
with an identity mapping for the .idmap.text section. This means that
users of the identity map do not need to manage their own pgd and can
instead annotate their functions with __idmap or, in the case of assembly
code, place them in the correct section.
Acked-by: NDave Martin <dave.martin@linaro.org>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NLorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>

setup_mm_for_reboot() doesn't make use of its argument, so remove it.
Acked-by: NNicolas Pitre <nico@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NH Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

These files all make use of one of the EXPORT_SYMBOL variants
or the THIS_MODULE macro.  So they will need <linux/export.h>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Building these files does not reveal a hidden need for
any of these.  Since module.h brings in the whole kitchen
sink, it just needlessly adds 30k+ lines to the cpp burden.

There are probably lots more, but ARM files of mach-* and plat-*
don't get coverage via a simple yesconfig build.  They will have
to be cleaned up and tested via using their respective configs.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

The patch merges the build of imx3 and imx6.  The Kconfig symbol
ARCH_IMX_V6_V7 is introduced to replace ARCH_MX3 and ARCH_MX6.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

It adds generic device tree based machine support for imx6q.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

This adds basic support for the Calxeda Highbank platform.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Reviewed-by: NJamie Iles <jamie@jamieiles.com>
Reviewed-by: NShawn Guo <shawn.guo@linaro.org>

This allows mapping external memory such as SRAM for use.

This is needed for some small chunks of code, such as reprogramming
SDRAM memory source clocks that can't be executed in SDRAM. Other
use cases include some PM related code.
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: NAndres Salomon <dilinger@queued.net>
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

we save the l2x0 registers at the first initialization, and platform codes
can get them to restore l2x0 status after wakeup.

Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

this patch fixes the error in Rob Herring's
ARM: 7009/1: l2x0: Add OF based initialization
http://www.spinics.net/lists/arm-kernel/msg131123.html
it has been in rmk/for-next with commit 41c86ff5b

Cc: Shawn Guo <shawn.guo@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Acked-by: NRob Herring <robherring2@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

using cpu_relax in busy loops is a well-known idiom in the kernel.
It's more for documentation purposes than technically needed here.
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NJamie Iles <jamie@jamieiles.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This adds probing for ARM L2x0 cache controllers via device tree. Support
includes the L210, L220, and PL310 controllers. The binding allows setting
up cache RAM latencies and filter addresses (PL310 only).
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NOlof Johansson <olof@lixom.net>
Acked-by: NBarry Song <21cnbao@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The definition of __exception_irq_entry for
CONFIG_FUNCTION_GRAPH_TRACER=y needs linux/ftrace.h, but this creates a
circular dependency with it's current home in asm/system.h. Create
asm/exception.h and update all current users.

v4:	- rebase to rmk/for-next
v3:	- remove redundant includes of linux/ftrace.h
v2:	- document the usage restricitions of __exception*

Cc: Zoltan Devai <zdevai@gmail.com>
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch defines the (pte|pmd)val_t as u32 and changes the page table
types to be based on these. The PMD bits are converted to the
corresponding type using the _AT macro.

The flush_pmd_entry/clean_pmd_entry argument was changed to (void *) to
allow them to be used with both PGD and PMD pointers and avoid code
duplication.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Support for the cpu_suspend functions is only built-in
when CONFIG_PM_SLEEP is enabled, but omap3/4, exynos4
and pxa always call cpu_suspend when CONFIG_PM is enabled.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

The two functions cpu_is_v6_unaligned and safe_usermode
are only defined when CONFIG_PROC_FS is enabled, but
are used outside of the #ifdef.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Dave Martin <dave.martin@linaro.org>

The VM subsystem assumes that there are valid memmap entries from
the bank start aligned to MAX_ORDER_NR_PAGES.

On the Ux500 we have a lot of mem=N arguments on the commandline
triggering this bug several times over and causing kernel
oops messages.

Cc: stable@kernel.org
Cc: Michael Bohan <mbohan@codeaurora.org>
Cc: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: NJohan Palsson <johan.palsson@stericsson.com>
Signed-off-by: NRabin Vincent <rabin.vincent@stericsson.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

If the attempt to map a page for DMA fails (eg, because we're out of
mapping space) then we must not hold on to the page we allocated for
DMA - doing so will result in a memory leak.

Cc: <stable@kernel.org>
Reported-by: NBryan Phillippe <bp@darkforest.org>
Tested-by: NBryan Phillippe <bp@darkforest.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

On certain architectures, there might be a need to mark certain
addresses with strongly ordered memory attributes to avoid ordering
issues at the interconnect level.

On OMAP4, the asynchronous bridge buffers can only be drained
with strongly ordered accesses and hence the need to mark the
memory strongly ordered.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NWoodruff Richard <r-woodruff2@ti.com>
Tested-by: NVishwanath BS <vishwanath.bs@ti.com>

There is no need to save and restore the context ID register on ARMv6
and ARMv7 with a temporary page table as we write the context ID
register when we switch back to the real page tables for the thread.

Moreover, the temporary page tables do not contain any non-global
mappings, so the context ID value should not be used.  To be safe,
initialize the register to a reserved context ID value.
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NShawn Guo <shawn.guo@linaro.org>
Tested-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Only use the preallocated page table during the resume, not while
suspending.  This avoids the overhead of having to switch unnecessarily
to the resume page table in the suspend path.
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NShawn Guo <shawn.guo@linaro.org>
Tested-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Preallocate a page table and setup an identity mapping for the MMU
enable code.  This means we don't have to "borrow" a page table to
do this, avoiding complexities with L2 cache coherency.
Tested-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: NShawn Guo <shawn.guo@linaro.org>
Tested-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch implements a workaround for erratum 764369 affecting
Cortex-A9 MPCore with two or more processors (all current revisions).
Under certain timing circumstances, a data cache line maintenance
operation by MVA targeting an Inner Shareable memory region may fail to
proceed up to either the Point of Coherency or to the Point of
Unification of the system. This workaround adds a DSB instruction before
the relevant cache maintenance functions and sets a specific bit in the
diagnostic control register of the SCU.

Cc: <stable@kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Annotate the low level hardware locks which must not be preempted.

In mainline this change documents the low level nature of
the lock - otherwise there's no functional difference. Lockdep
and Sparse checking will work as usual.
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Commit be020f86, "ARM: entry: abort-macro: specify registers to be
used for macros", while replacing register numbers with macro parameter
names, mismatched the name used for r1. For me, this resulted in user
space built for EABI with -march=armv4t -mtune=arm920t -mthumb-interwork
-mthumb broken on my OMAP1510 based Amstrad Delta (old ABI and no thumb
still worked for me though).

Fix this by using correct parameter name fsr instead of mismatched psr,
used by callers for another purpose.
Signed-off-by: NJanusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Fighting unfixed U-Boots and other beasts that may the cache in
a locked-down state when starting the kernel, we make sure to
disable all cache lock-down when initializing the l2x0 so we
are in a known state.

Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Rabin Vincent <rabin.vincent@stericsson.com>
Cc: Adrian Bunk <adrian.bunk@movial.com>
Cc: Rob Herring <robherring2@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Reported-by: NJan Rinze <janrinze@gmail.com>
Tested-by: NRobert Marklund <robert.marklund@stericsson.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

When ARCH_HAS_HOLES_MEMORYMODEL is selected, pfn_valid calls
memblock_is_memory to test validity of a pfn:

> memblock_is_memory(pfn << PAGE_SHIFT);

On LPAE systems this cuts off the top bits, as the shift occurs before
the value is promoted to a phys_addr_t.

This patch replaces the shift with a call to __pfn_to_phys (which casts
pfn to phys_addr_t before shifting), preventing the loss of significant
bits.
Signed-off-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

For ARMv7 kernels running in the non-secure world, writing to the
auxillary control register causes an abort, so we must avoid directly
writing the auxillary control register.  If the ACR has already been
reinitialized by SoC code, don't try to restore it.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Add a dsb after the isb to ensure that the previous writes to the
CP15 registers take effect before we enable the MMU.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

ARM920 and ARM926 save four registers, not three.  Fix the size of
the suspend region required.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

r1 stores the v:p offset from the CPU invariant resume code, and is
expected to be preserved by the CPU specific code.  Overwriting it is
not a good idea.

We've managed to get away with it on sa1100 platforms because most
happen to have PHYS_OFFSET == PAGE_OFFSET, but that may not be the
case depending on kernel configuration.  So fix this latent bug.

This fixes xsc3 as well which was saving and restoring this register
independently.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

cpu_v7_reset disables the MMU and then branches to the provided address.
On Thumb-2 kernels, we should take care to clear the Thumb Exception
enable bit in the System Control Register, otherwise this may wreak
havok in the code to which we are branching (for example, an ARM kernel
image via kexec).
Reviewed-by: NDave Martin <dave.martin@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

PGDIR_SHIFT and PMD_SHIFT for the classic 2-level page table format have
the same value (21). This patch converts the PGDIR_* uses in the kernel
to the PMD_* equivalent so that LPAE builds can reuse the same code.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There are now no platforms which set this macro.
Signed-off-by: NJon Medhurst <tixy@yxit.co.uk>

This function can be called during boot to increase the size of the consistent
DMA region above it's default value of 2MB. It must be called before the memory
allocator is initialised, i.e. before any core_initcall.
Signed-off-by: NJon Medhurst <tixy@yxit.co.uk>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>

This patch is a workaround for the 364296 ARM1136 r0p2 erratum (possible
cache data corruption with hit-under-miss enabled). It sets the
undocumented bit 31 in the auxiliary control register and the FI bit in
the control register, thus disabling hit-under-miss without putting the
processor into full low interrupt latency mode.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Tested-by: NSiarhei Siamashka <siarhei.siamashka@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

With the UM_SIGNAL alignment fault mode, no siginfo structure is
passed to userspace.

POSIX specifies how siginfo_t should be populated for alignment
faults, so this patch does just that:

  * si_signo = SIGBUS
  * si_code = BUS_ADRALN
  * si_addr = misaligned data address at which access was attempted
Signed-off-by: NDave Martin <dave.martin@linaro.org>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: NKirill A. Shutemov <kirill@shutemov.name>
Reviewed-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Currently, it's possible to set the kernel to ignore alignment
faults when changing the alignment fault handling mode at runtime
via /proc/sys/alignment, even though this is undesirable on ARMv6
and above, where it can result in infinite spins where an un-fixed-
up instruction repeatedly faults.

In addition, the kernel clobbers any alignment mode specified on
the command-line if running on ARMv6 or above.

This patch factors out the necessary safety check into a couple of
new helper functions, and checks and modifies the fault handling
mode as appropriate on boot and on writes to /proc/cpu/alignment.

Prior to ARMv6, the behaviour is unchanged.

For ARMv6 and above, the behaviour changes as follows:

  * Attempting to ignore faults on ARMv6 results in the mode being
    forced to UM_FIXUP instead.  A warning is printed if this
    happened as a result of a write to /proc/cpu/alignment.  The
    user's UM_WARN bit (if present) is still honoured.

  * An alignment= argument from the kernel command-line is now
    honoured, except that the kernel will modify the specified mode
    as described above.  This is allows modes such as UM_SIGNAL and
    UM_WARN to be active immediately from boot, which is useful for
    debugging purposes.
Signed-off-by: NDave Martin <dave.martin@linaro.org>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

poison_init_mem() used a loop of:

	while ((count = count - 4))

which has 2 problems - an off by one error so that we do one less word
than we should, and the other is that if count == 0 then we loop forever
and poison too much.  On a platform with HAVE_TCM=y but nothing in the
TCM's, this caused corruption and the platform failed to boot.
Acked-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: NJamie Iles <jamie@jamieiles.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>