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64,840 commits

Author SHA1 Message Date
Stepan Moskovchenko
33069739d1 msm: iommu: Miscellaneous code cleanup
Remove some unneeded assignments and messages, restructure
a failure path in iova_to_phys, and make __flush_iotlb
return int in preparation for adding IOMMU clock control.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 16:12:00 -08:00
Stepan Moskovchenko
100832c9b6 msm: iommu: Support cache-coherent memory access
Add support for allowing IOMMU memory transactions to be
cache coherent, eliminating the need for software cache
management in certain situations. This can lead to
improvements in performance and power usage, assuming the
multimedia core's access pattern exhibits spatial locality
and that its working set fits into the cache.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 16:10:53 -08:00
Stepan Moskovchenko
08bd683978 msm: iommu: Definitions for extended memory attributes
Add the register field definitions and memory attribute
definitions that will be needed to support IOMMU
transactions with cache-coherent memory access.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 16:05:05 -08:00
Stepan Moskovchenko
0ab84745ef msm: iommu: Kconfig dependency for the IOMMU API
Make the IOMMU driver select the IOMMU API in the kernel
configuration.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 16:03:53 -08:00
Stepan Moskovchenko
00d4b2bb03 msm: iommu: Check if device is already attached
An IOMMU device can only be attached to one IOMMU domain at
any given time. Check whether the device is already
attached to a domain before allowing it to be attached to
another domain. If so, return busy.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 16:03:51 -08:00
Stepan Moskovchenko
2607b0a260 msm: iommu: Kconfig item for cacheable page tables
Add a Kconfig item to allow the IOMMU page tables to be
coherent in the L2 cache. This generally reduces IOTLB miss
latencies and has been shown to improve multimedia
performance.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 16:03:16 -08:00
David S. Miller
12c7a35ee6 sparc: Delete prom_*getchar().
Completely unused.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-30 14:53:05 -08:00
Tony Lindgren
52aa8c539d Merge branch 'ctrl-wip/mux-omap4-v4' of git://gitorious.org/omap-pm/linux into omap-for-linus 2010-11-30 14:46:36 -08:00
Tony Lindgren
55a4e78952 Merge branch 'pm-hwmod-i2c' of ssh://master.kernel.org/pub/scm/linux/kernel/git/khilman/linux-omap-pm into omap-for-linus 2010-11-30 14:45:49 -08:00
David S. Miller
e62cac1fd0 sparc: Pass buffer pointer all the way down to prom_{get,put}char().
This gets us closer to being able to eliminate the use
of dynamic and stack based buffers, so that we can adhere
to the "no buffer addresses above 4GB" rule for PROM calls.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-30 14:33:29 -08:00
Tony Lindgren
9c7bc451e4 Merge branches 'devel-cleanup', 'devel-serial' and 'devel-board' into omap-for-linus 2010-11-30 14:13:15 -08:00
Andrei Emeltchenko
662b083a87 omap: Serial: Define register access modes in LCR
Access to some registers depends on register access mode
Three different modes are available for OMAP (at least)
• Operational mode     LCR_REG[7] = 0x0
• Configuration mode A LCR_REG[7] = 0x1 and LCR_REG[7:0]! = 0xBF
• Configuration mode B LCR_REG[7] = 0x1 and LCR_REG[7:0]  = 0xBF

Define access modes and remove redefinitions and magic numbers
in serial drivers (and later in bluetooth driver).

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2010-11-30 14:11:49 -08:00
Andrei Emeltchenko
498cb95175 OMAP: Serial: Define OMAP uart MDR1 reg and remove magic numbers
Define MDR1 register serial definitions used in serial and
bluetooth drivers.
Change magic number to ones defined in serial_reg for omap1/2
serial driver.
Remove redefined MDR1 register definitions in omap-serial driver.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@nokia.com>
Acked-by: G, Manjunath Kondaiah <manjugk@ti.com>
Acked-by: Govindraj.R <govindraj.raja@ti.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2010-11-30 14:11:49 -08:00
Stepan Moskovchenko
f6f41eb9cc msm: iommu: Don't flush page tables if no devices attached
Don't flush the page tables on an IOMMU domain if there are
no IOMMU devices attached to the domain. The act of
attaching to the domain will cause an implicit flush of
those areas if the page tables are configured to not be L2
cacheable.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 14:04:21 -08:00
Stepan Moskovchenko
516cbc793e msm: iommu: Mark functions with the right section names
Mark the init and exit functions as __init and __exit where
appropriate.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 14:03:36 -08:00
Stepan Moskovchenko
e8952e3b32 msm: iommu: Support for the 2nd GFX core's IOMMU
Add the platform data and resources needed for the second
2D graphics core's IOMMU.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 14:02:56 -08:00
Stepan Moskovchenko
ff25ff842e msm: iommu: Revise GFX2D0 IOMMU contexts and M2V mappings
Based on recommendations from chip designers,
optimize the Machine ID to translation context
mappings for the first 2D core's IOMMU. Remove the
"gfx2d0_texv3_smmu" context, as it is no longer needed
under the new mapping scheme.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 14:01:32 -08:00
Stepan Moskovchenko
a5fcd5f59a msm: iommu: Revise GFX3D IOMMU contexts and M2V mappings
Based on recommendations from chip designers,
optimize the Machine ID to translation context
mappings for the 3D core's IOMMU. Remove the
the "gfx3d_smmu" context device, as it is no longer
needed under the new mapping scheme.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
[dwalker@codeaurora.org: updated commit text]
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 13:56:17 -08:00
Stepan Moskovchenko
12943325cd msm: iommu: Use more consistent naming in platform data
Rename all the IOMMU platform devices so that the names are
more consistent with the rest of the codebase.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 13:54:43 -08:00
Stepan Moskovchenko
c4bd2eebee msm: iomap: Addresses and IRQs for 2nd GFX core IOMMU
Add register addresses and IRQ numbers for the IOMMU used
for the second 2D graphics core.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 13:53:45 -08:00
Stepan Moskovchenko
23513c3b39 msm: iommu: Increase maximum MID size to 5 bits
On msm8x60, the MID field on the AXI connection to the
IOMMU can be up to five bits wide. Thus, allow the IOMMU
context platform data to map up to 32 MIDs.

Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 13:53:08 -08:00
Gregory Bean
70cc2c00d7 msm: gpio: Add irq support to v2 gpiolib.
Complete the MSM v2 gpio subsystem by adding irq_chip.

Signed-off-by: Gregory Bean <gbean@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 13:51:52 -08:00
Gregory Bean
0cc2fc1f2f msm: gpio: Add v2 gpio support to MSM SoCs.
Beginning with the MSM8x60, the hardware block responsible for gpio
support changes.  Provide gpiolib support for the new v2 architecture.

Cc: Baruch Siach <baruch@tkos.co.il>
Cc: Pavan Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Gregory Bean <gbean@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
2010-11-30 13:51:17 -08:00
Srinath
1cb125caf2 omap: AM3517/05: Add craneboard support
Craneboard is a hardware development platform based on the
Sitara AM3517 ARM Cortex - A8 microprocessor device. This is a
low cost reference design.

This patch adds basic board file. Detailed support will follow in
subsequent patches.

  [1] http://www.ti.com/arm
  [2] http://www.mistralsolutions.com/products/craneboard.php

Signed-off-by: Srinath <srinath@mistralsolutions.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2010-11-30 13:48:46 -08:00
Janusz Krzysztofik
9632f9890e OMAP1: drop AMS_DELTA_FIQ config option
This patches removes a config option that was used to select a FIQ
handler to be build for Amstrad Delta, as required by the on-board serio
interface driver. Not having any problem reports received since it was
introduced in 2.6.35, the FIQ handler can now be built and initialized by
default, thus reqiring no extra config option.

Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2010-11-30 13:48:46 -08:00
Felipe Balbi
c6c4dea401 arm: omap: zoom: substitute gpio number with symbolic name
It's easier to understand what that number means and
also avoids problems if we ever have to change it.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2010-11-30 13:48:46 -08:00
Felipe Balbi
2082685385 arm: omap: combine zoom2 and zoom3 board-files
They are extremely similar anyway, let's get rid
of one file.

While at that, also remove the empty zoom_config
variable.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2010-11-30 13:48:45 -08:00
Enric Balletbo i Serra
235228ba21 omap3: IGEP v2: Improve igep2_flash_init() function
The changes are:
  - Use 'for' loop instead 'while' loop.
  - No need to initialize ret to 0, we're assigning it right after.
  - No need to check for onenandcs < GPMC_CS_NUM here, it will always be true.

Signed-off-by: Enric Balletbo i Serra <eballetbo@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2010-11-30 13:48:25 -08:00
Enric Balletbo i Serra
ae3e033362 omap3: IGEP v2: Remove igep2_config array
omap_board_config_size is implicitly initialized to 0 in
plat-omap/common.c, get_config() won't dereference omap_board_config,
so we can remove the empty igep2_config array.

Signed-off-by: Enric Balletbo i Serra <eballetbo@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2010-11-30 13:48:09 -08:00
Keshava Munegowda
6aa85a5ae6 omap4: 4430sdp: enable the ehci port on 4430SDP
The OMAP4 SDP has an SMSC3320 PHY hooked up to EHCI on Port1.
The PHY power is controlled by GPIO 157.

Turn on the PHY power, and register the controller at init.

Signed-off-by: Keshava Munegowda <keshava_mgowda@ti.com>
Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2010-12-01 02:43:05 +05:30
Anand Gadiyar
56976b6ac4 arm: omap4: select USB_ARCH_HAS_EHCI
The OMAP4 has an on-chip EHCI controller. Select USB_ARCH_HAS_EHCI
to allow the EHCI driver to be built on OMAP4.

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2010-12-01 02:42:36 +05:30
Anand Gadiyar
becf0737cf arm: omap4: usb: add platform init code for EHCI
- Add platform init code for EHCI on OMAP4
- Add pad configuration for PHY and TLL modes

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2010-12-01 02:42:13 +05:30
Anand Gadiyar
811406c2e6 arm: omap4: add USBHOST and related base addresses
Add base addresses for USBHOST, USBTLL, EHCI and OHCI to
the header file.

This will disappear when the drivers are converted to use
the hwmod database, however this patch is needed until then.

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2010-12-01 02:36:08 +05:30
Anand Gadiyar
1ed85659a2 omap: usb: ehci: introduce HSIC mode
The EHCI controller in OMAP4 supports a new interface mode - HSIC.
Add this to the list of modes supported on OMAP3.

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2010-12-01 02:35:28 +05:30
Anand Gadiyar
5467e16d89 omap: clock: add clkdev aliases for EHCI clocks
Add clkdev aliases for the USBHOST and USBTLL clocks on OMAP3 and
OMAP4, so that the driver can refer to the clocks using a common alias.

This will disappear when the driver is converted to use the hwmod
database, but until then this patch is needed.

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2010-12-01 02:33:29 +05:30
Jean-Christophe PLAGNIOL-VILLARD
3b24f0950b at91/board-yl-9200: fix typo in video support
for the epson frambuffer support it's CONFIG_FB_S1D13XXX
not CONFIG_FB_S1D135XX

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2010-11-30 17:23:41 +01:00
Jean-Christophe PLAGNIOL-VILLARD
82d5b5c8da at91/picotux200: remove commenting usb device and dataflash support
as based on http://www.picotux.com/pt200/picotux200.pdf
these board does not have such I/O

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
2010-11-30 17:23:02 +01:00
Jean-Christophe PLAGNIOL-VILLARD
985f554d8f at91: rename rm9200ek and rm9200dk board file name
to be a few more concistant with the other boards

as ek is for evaluation kit and dk for development kit

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Victor <linux@maxim.org.za>
2010-11-30 17:22:20 +01:00
Jean-Christophe PLAGNIOL-VILLARD
55d83b0a6e at91rm9200ek: fix warning: 'ek_mmc_data' defined but not used
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Victor <linux@maxim.org.za>
2010-11-30 17:22:07 +01:00
Jean-Christophe PLAGNIOL-VILLARD
8e79d2d4e7 at91rm9200dk: fix warning: 'dk_mmc_data' defined but not used
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Victor <linux@maxim.org.za>
2010-11-30 17:21:55 +01:00
Jean-Christophe PLAGNIOL-VILLARD
8ae8cd978b at91: Convert remaining boards to new-style UART initialization
Convert the following AT91RM9200-based boards to the new-style UART
initialization:
  - Ajeco 1ARM Single Board Computer
  - Sperry-Sun KAFA board
  - picotux 200

Remove the deprecated at91_init_serial

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Victor <linux@maxim.org.za>
2010-11-30 17:21:29 +01:00
Dave Martin
ed7c84d548 ARM: 6505/1: kprobes: Don't HAVE_KPROBES when CONFIG_THUMB2_KERNEL is selected
Currently, the kprobes implementation for ARM only supports the ARM
instruction set, so it only works if CONFIG_THUMB2_KERNEL is not
enabled.

Until kprobes is updated to work with Thumb-2, turning it on will
cause horrible things to happen, so this patch disables it for now.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30 13:44:28 +00:00
Dave Martin
618d9c8f9e ARM: 6508/1: vexpress: Correct data alignment in headsmp.S for CONFIG_THUMB2_KERNEL
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.

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>
2010-11-30 13:44:27 +00:00
Dave Martin
725ca4adae ARM: 6507/1: RealView: Correct data alignment in headsmp.S for CONFIG_THUMB2_KERNEL
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.

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>
2010-11-30 13:44:27 +00:00
Dave Martin
a75e5248c5 ARM: 6504/1: Thumb-2: Fix long-distance conditional branches in head.S for Thumb-2.
The 32-bit conditional branches in Thumb-2 have a shorter range
(+/-512K) than their ARM counterparts (+/-32MB).  The linker does
not currently generate trampolines to extend the range of these
Thumb-2 conditional branches, resulting in link errors when vmlinux
is sufficiently large, e.g.:

head.o:(.text+0x464): relocation truncated to fit: R_ARM_THM_JUMP19

This patch forces the longer-range, unconditional branch encoding
by use of an explicit IT instruction.  The resulting branches are
triggered on the same conditions as before.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30 13:44:26 +00:00
Dave Martin
26e5ca93dd ARM: 6503/1: Thumb-2: Restore sensible zImage header layout for CONFIG_THUMB2_KERNEL
The code which makes up the zImage header intends to leave a
32-byte gap followed by a branch to the real entry point, a magic
number, and a word containing the absolute entry point address.

This gets messed up with with CONFIG_THUMB2_KERNEL, because the
size of the initial padding NOPs changes.

Instead, the header can be made fully compatible by restoring it to
ARM.

In the Thumb-2 case, we can replace the initial NOPs with a
sequence which switches to Thumb and jumps to the real entry point.

As a consequence, the zImage entry point is now always ARM, so no
special magic is needed any more for the uImage rules in the
Thumb-2 case.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-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>
2010-11-30 13:44:26 +00:00
Dave Martin
bfa64c4ab1 ARM: 6502/1: Thumb-2: Fix CONFIG_THUMB2_KERNEL breakage in compressed/head.S
Some instruction operand combinations are used here which are nor
permitted in Thumb-2.

In particular, most uses of pc as an operand are disallowed in
Thumb-2, and deprecated in ARM from ARMv7 onwards.

The modified code introduced by this patch should be compatible
with all architecture versions >= v3, with or without
CONFIG_THUMB2_KERNEL.

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>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2010-11-30 13:44:25 +00:00
Dave Martin
6323875db2 ARM: 6501/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in mm/proc-v7.S
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>
2010-11-30 13:44:25 +00:00
Dave Martin
4f79a5dd7c ARM: 6500/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in kernel/head.S
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.

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>
2010-11-30 13:44:24 +00:00
Dave Martin
077248fcce ARM: 6499/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in bootp/init.S
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.

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>
2010-11-30 13:44:24 +00:00