AM18x/DA850/OMAP-L138 SoCs have variants that can operate
at a maximum of 456 MHz at 1.3V operating point. Also the
1.2V operating point has a variant that can support a maximum
of 375 MHz.
This patch adds three new OPPs (456 MHz, 408 MHz and 372 MHz)
to the list of DA850 OPPs.
Not all silicon is qualified to run at higher speeds and
unfortunately the maximum speed the chip can support can only
be determined from the label on the package (not software
readable).
Because of this, we depend on the maximum speed grade information
to be provided to us in some board specific way. The board informs
the maximum speed grade information by setting the da850_max_speed
variable.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Use the mach-davinci/Kconfig to enable gpio-keys-polled as default when
da850-evm machine is enabled.
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
CC: Kevin Hilman <khilman@deeprootsystems.com>
CC: "Nori, Sekhar" <nsekhar@ti.com>
CC: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
This patch adds a pca953x platform device for the tca6416 found on the evm
baseboard. The tca6416 is a GPIO expander, also found on the UI board at a
separate I2C address. The pins of the baseboard IO expander are connected to
software reset, deep sleep enable, test points, a push button, DIP switches and
LEDs.
Add support for the push button, DIP switches and LEDs and test points (as
free GPIOs). The reset and deep sleep enable connections are reserved by the
setup routine so that userspace can't toggle those lines.
The existing tca6416-keypad driver was not employed because there was no
apararent way to register the LEDs connected to gpio's on the tca6416 while
simultaneously registering the tca6416-keypad instance.
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Reviewed-by: Chris Cordahi <christophercordahi@nanometrics.ca>
CC: Govindarajan, Sriramakrishnan <srk@ti.com>
Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
CC: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
The setup and teardown methods of the UI expander reference the SEL_{A,B,C}
pins by 'magic number' in each function. This uses the common enum for their offsets
in the expander setup and teardown functions.
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Reviewed-by: Chris Cordahi <christophercordahi@nanometrics.ca>
Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
CC: Victor Rodriguez <vm.rod25@gmail.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
This patch adds EV_KEYs for each of the 8 pushbuttons on the UI board via a
gpio-key device.
The expander is a tca6416; it controls the SEL_{A,B,C} lines which enable and
disable the peripherals found on the UI board in addition to the 8 pushbuttons
mentioned above. The reason the existing tca6416-keypad driver is not employed
is because there was no aparent way to keep the gpio lines used as
SEL_{A,B,C} registered while simultaneously registering the pushbuttons as a
tca6416-keypad instance.
Some experimentation with the polling interval was performed; we were searching
for the largest polling interval that did not affect the feel of the
responsiveness of the buttons. It is very subjective but 200ms seems to be a
good value that accepts firm pushes but rejects very light ones. The key values
assigned to the buttons were arbitrarily chosen to be F1-F8.
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Reviewed-by: Chris Cordahi <christophercordahi@nanometrics.ca>
CC: Govindarajan, Sriramakrishnan <srk@ti.com>
Reviewed-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
CC: Kevin Hilman <khilman@deeprootsystems.com>
CC: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Ensure that the at24 eeprom driver is selected for certain boards that
need boot data (e.g. MAC address) from EEPROM.
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
There was a single case of 'da850evm' prefix in the board-da850-evm.c file
where the reset of the prefixes were 'da850_evm'; change it to 'da850_evm' for
consistency.
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Change the mach-davinci Kconfig file so that GPIO_PCA953X is default when
MACH_DAVINCI_DA850_EVM is set instead of always selecting. This allows users
to compile pca953x as a module.
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
CC: Sergei Shtylyov <sshtylyov@mvista.com>
CC: Nori, Sekhar <nsekhar@ti.com>
Reviewed-by: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
When the RMII PHY on the UI board is enabled with CONFIG_DA850_UI_RMII
then then following will be printed to the console when warnings are
also enabled:
WARNING: at drivers/gpio/gpiolib.c:1567 __gpio_set_value+0x4c/0x5c()
Modules linked in:
[<c002c6ac>] (unwind_backtrace+0x0/0xf8) from [<c003b48c>] (warn_slowpath_common+0x4c/0x64)
[<c003b48c>] (warn_slowpath_common+0x4c/0x64) from [<c003b4c0>] (warn_slowpath_null+0x1c/0x24)
[<c003b4c0>] (warn_slowpath_null+0x1c/0x24) from [<c01aed60>] (__gpio_set_value+0x4c/0x5c)
[<c01aed60>] (__gpio_set_value+0x4c/0x5c) from [<c0033bd4>] (da850_evm_ui_expander_setup+0x1e4/0x2
44)
[<c0033bd4>] (da850_evm_ui_expander_setup+0x1e4/0x244) from [<c02e2e1c>] (pca953x_probe+0x1f8/0x29
0)
<snip>
Traced the WARN_ON to the gpio_set_value(rmii_sel,0) call in
da850_evm_setup_emac_rmii. Replacing the call with the _cansleep variant
results in no more warning. Also replacing the gpio_set_value calls in the
teardown function.
Signed-off-by: Ben Gardiner <bengardiner@nanometrics.ca>
Reviewed-by: Chris Cordahi <christophercordahi@nanometrics.ca>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
aemif_calc_rate() can return a negative error value, so all the
variables that get tested for this value need to be signed.
The maximum bit width of WSETUP(WSETUP_MAX) appears to be 30 bits
(0xf << 26). Using a signed instead of an unsigned integer
shouldn't make a difference here.
Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
A common do-while loop can be factored out from the end of
the branches.
Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
This patch applies the following modifications to the tnetv107x clock tree:
- reparent tnetv107x usb clocks to usbss
- mark timer1 as always enabled
- enable set_rate on pll divider output clocks
- adjust tnetv107x tsc sysclk rate lower to fix invalid reset defaults
Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
This patch modifies the sysclk rate setting code to use the divider mask
specified in pll_data. Without this, devices with different divider ranges
(e.g. tnetv107x) fail.
Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Overwrite the default implementation of sched_clock that is based on
jiffies by something more precise. This improves timestamps in ftrace.
Implementation is copied from OMAP platform code.
Signed-off-by: Andreas Gaeer <Andreas.Gaer@baslerweb.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
Commit 0ea1293009 ("arm: return both physical and virtual addresses
from addruart") took out the test for MMU on/off but didn't switch the
ldr instructions to no longer be conditionals based on said test.
Fix that.
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Colin Cross <ccross@android.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* master.kernel.org:/home/rmk/linux-2.6-arm:
ARM: 6524/1: GIC irq desciptor bug fix
ARM: 6523/1: iop: ensure sched_clock() is notrace
ARM: 6456/1: Fix for building DEBUG with sa11xx_base.c as a module.
ARM: 6519/1: kuser: Fix incorrect cmpxchg syscall in kuser helpers
ARM: 6505/1: kprobes: Don't HAVE_KPROBES when CONFIG_THUMB2_KERNEL is selected
ARM: 6508/1: vexpress: Correct data alignment in headsmp.S for CONFIG_THUMB2_KERNEL
ARM: 6507/1: RealView: Correct data alignment in headsmp.S for CONFIG_THUMB2_KERNEL
ARM: 6504/1: Thumb-2: Fix long-distance conditional branches in head.S for Thumb-2.
ARM: 6503/1: Thumb-2: Restore sensible zImage header layout for CONFIG_THUMB2_KERNEL
ARM: 6502/1: Thumb-2: Fix CONFIG_THUMB2_KERNEL breakage in compressed/head.S
ARM: 6501/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in mm/proc-v7.S
ARM: 6500/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in kernel/head.S
ARM: 6499/1: Thumb-2: Correct data alignment for CONFIG_THUMB2_KERNEL in bootp/init.S
ARM: 6498/1: vfp: Correct data alignment for CONFIG_THUMB2_KERNEL
ARM: 6497/1: kexec: Correct data alignment for CONFIG_THUMB2_KERNEL
ARM: 6496/1: GIC: Do not try to register more then NR_IRQS interrupts
ARM: cns3xxx: Fix build with CONFIG_PCI=y
gic_set_cpu will directly use irq_desc[]. If CONFIG_SPARSE_IRQ is
enabled, there is no irq_desc[]. So we need use irq_to_desc(irq) to
get the descriptor for irq.
Signed-off-by: Chao Xie <chao.xie@marvell.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/kyle/parisc-2.6:
parisc: Fix GSC PS/2 driver name for keyboard and mouse
parisc: KittyHawk LCD fix
parisc: convert the rest of the irq handlers to simple/percpu
parisc: fix dino/gsc interrupts
parisc: remove redundant initialization in sigsegv path of sys_rt_sigreturn
The generic conversion eliminates the spurious no_ack and no_end
routines, converts all the cascaded handlers to handle_simple_irq() and
makes iosapic use a modified handle_percpu_irq() to become the same as
the CPU irq's. This isn't an essential change, but it eliminates the
mask/unmask overhead of handle_level_irq().
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Tested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
The essential problem we're currently having is that dino (and gsc) is a
cascaded CPU interrupt. Under the old __do_IRQ() handler, our CPU
interrupts basically did an ack followed by an end. In the new scheme,
we replaced them with level handlers which do a mask, an ack and then an
unmask (but no end). Instead, with the renaming of end to eoi, we
actually want to call the percpu flow handlers, because they actually
have all the characteristics we want.
This patch does the conversion and gets my C360 booting again.
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
Include sched.h to ensure sched_clock() has the notrace
annotation, and mark any functions it calls as notrace
too.
Include sched.h to ensure sched_clock() has the notrace
annotation, and mark any functions it calls as notrace
too.
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The existing code invokes the syscall with rubbish in r7,
due to what looks like an incorrect literal load idiom.
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>
* '2.6.37-rc4-pvhvm-fixes' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
xen: unplug the emulated devices at resume time
xen: fix save/restore for PV on HVM guests with pirq remapping
xen: resume the pv console for hvm guests too
xen: fix MSI setup and teardown for PV on HVM guests
xen: use PHYSDEVOP_get_free_pirq to implement find_unbound_pirq
* 'upstream/core' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
xen: allocate irq descs on any NUMA node
xen: prevent crashes with non-HIGHMEM 32-bit kernels with largeish memory
xen: use default_idle
xen: clean up "extra" memory handling some more
* 'upstream/bugfix' of git://git.kernel.org/pub/scm/linux/kernel/git/jeremy/xen:
xen: x86/32: perform initial startup on initial_page_table
xen: don't bother to stop other cpus on shutdown/reboot
* 'sh-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6:
sh: se/7724: Remove FSI/B of GPIO init code
sh: se/7724: Update clock framework of FSI clock to non-legacy
sh: Assume new page cache pages have dirty dcache lines.
sh: boards: mach-se: use IS_ERR() instead of NULL check
sh: Add div6_reparent_clks to clock framework for FSI
dma: shdma: add a MODULE_ALIAS() to allow module autoloading
Implement asm/syscall.h for the MN10300 arch.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On stock 2.6.37-rc4, running:
# mount lilith:/export /mnt/lilith
# find /mnt/lilith/ -type f -print0 | xargs -0 file
crashes the machine fairly quickly under Xen. Often it results in oops
messages, but the couple of times I tried just now, it just hung quietly
and made Xen print some rude messages:
(XEN) mm.c:2389:d80 Bad type (saw 7400000000000001 != exp
3000000000000000) for mfn 1d7058 (pfn 18fa7)
(XEN) mm.c:964:d80 Attempt to create linear p.t. with write perms
(XEN) mm.c:2389:d80 Bad type (saw 7400000000000010 != exp
1000000000000000) for mfn 1d2e04 (pfn 1d1fb)
(XEN) mm.c:2965:d80 Error while pinning mfn 1d2e04
Which means the domain tried to map a pagetable page RW, which would
allow it to map arbitrary memory, so Xen stopped it. This is because
vm_unmap_ram() left some pages mapped in the vmalloc area after NFS had
finished with them, and those pages got recycled as pagetable pages
while still having these RW aliases.
Removing those mappings immediately removes the Xen-visible aliases, and
so it has no problem with those pages being reused as pagetable pages.
Deferring the TLB flush doesn't upset Xen because it can flush the TLB
itself as needed to maintain its invariants.
When unmapping a region in the vmalloc space, clear the ptes
immediately. There's no point in deferring this because there's no
amortization benefit.
The TLBs are left dirty, and they are flushed lazily to amortize the
cost of the IPIs.
This specific motivation for this patch is an oops-causing regression
since 2.6.36 when using NFS under Xen, triggered by the NFS client's use
of vm_map_ram() introduced in 56e4ebf877 ("NFS: readdir with vmapped
pages") . XFS also uses vm_map_ram() and could cause similar problems.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Nick Piggin <npiggin@kernel.dk>
Cc: Bryan Schumaker <bjschuma@netapp.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Alex Elder <aelder@sgi.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When remapping MSIs into pirqs for PV on HVM guests, qemu is responsible
for doing the actual mapping and unmapping.
We only give qemu the desired pirq number when we ask to do the mapping
the first time, after that we should be reading back the pirq number
from qemu every time we want to re-enable the MSI.
This fixes a bug in xen_hvm_setup_msi_irqs that manifests itself when
trying to enable the same MSI for the second time: the old MSI to pirq
mapping is still valid at this point but xen_hvm_setup_msi_irqs would
try to assign a new pirq anyway.
A simple way to reproduce this bug is to assign an MSI capable network
card to a PV on HVM guest, if the user brings down the corresponding
ethernet interface and up again, Linux would fail to enable MSIs on the
device.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
This follows the ARM change c01778001a
("ARM: 6379/1: Assume new page cache pages have dirty D-cache") for the
same rationale:
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().
This addresses issues seen with executing binaries from MMC, in
addition to some of the other HCDs that don't explicitly do cache
management for their pipe-in buffers.
Requested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
