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>

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>

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: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell 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: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell 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: Nsrinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

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: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NLinus Walleij <linus.walleij@stericsson.com>

The cache size is needed for to optimise range based
maintainance operations
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NLinus 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: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NLinus 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: NCatalin Marinas <catalin.marinas@arm.com>

This patch is in preparation for a subsequent patch which adds barriers
to the I/O accessors. Since the mandatory barriers may do an L2 cache
sync, this patch avoids a recursive call into l2x0_cache_sync() via the
write*() accessors and wmb() and a call into l2x0_cache_sync() with the
l2x0_lock held.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

On i.MX35 the L2X0_AUX_CTRL register does not have sensible reset
default values. Allow them to be overwritten with the aux_val/aux_mask
arguments passed to l2x0_init().
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The L310 cache controller's interface is almost identical
to the L210. One major difference is that the PL310 can
have up to 16 ways.

This change uses the cache's part ID and the Associativity
bits in the AUX_CTRL register to determine the number of ways.

Also, this version prints out the CACHE_ID and AUX_CTRL registers.
Acked-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NAcked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NJason S. McMullan <jason.mcmullan@netronome.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The L2x0 cache controllers need to explicitly drain their write buffer
even for Normal Noncacheable memory accesses.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch implements the work-around for the errata 588369.The secure
API is used to alter L2 debug register because of trust-zone.

This version updated with comments from Russell and Catalin and
generated against 2.6.33-rc6 mainline kernel. Detail
comments can be found:
http://www.spinics.net/lists/linux-omap/msg23431.htmlSigned-off-by: NWoodruff Richard <r-woodruff2@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch adds the cache maintainance by line helper functions.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There's no point having the hardware support background operations
if we issue a cache operation, and then wait for it to complete
before calculating the address of the next operation.  We gain no
advantage in the cache controller stalling the bus until completion.

What we should be doing is using the 'wait' time productively by
calculating the address of the next operation, and only then waiting
for the previous operation to complete.  This means that cache
operations can occur in parallel with the CPU calculating the next
address.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>

Taking the spinlock for every iteration is very expensive; instead,
batch iterations up into 4K blocks, releasing and reacquiring the
spinlock between each block.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>

If running in non-secure mode accessing
some registers of l2x0 will fault. So
check if l2x0 is already enabled, if so
do not access those secure registers.
Signed-off-by: Nsrinidhi kasagar <srinidhi.kasagar@stericsson.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The l2x0_inv_range() function doesn't handle unaligned addresses
correctly. It's necessary to clean the cache lines that are at the
start and end of the invalidate range, if the addresses are not aligned,
to prevent corruption of other data sharing the same cache line.
Signed-off-by: NRui Sousa <rui.p.m.sousa@gmail.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The background operations of the L2x0 cache controllers are aborted if
another operation is issued on the same or different core. This patch
protects the maintenance operation issuing/polling with a spinlock.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch adds the support for the L210/L220 (outer) cache
controller. The cache range operations are done by index/way since L2
cache controller only accepts physical addresses.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>