The "targets" exists to specify which files need the corresponding
".*_cmd" files to be included during the build. In other words, it
is used for files that need to detect the change of the command line
by if_changed, if_changed_dep, and if_changed_rule. While, these
files are just copied by "$(call cmd,shipped)". Adding them to the
"targets" is meaningless because $(call cmd,...) never creates
".*_cmd" files. Such files as ".lib1funcs.S.cmd", ".ashldi3.S.cmd"
do not exist in the first place.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When CONFIG_DEBUG_ICEDCC is set, we don't use the platform
specific putc() function, but use icedcc_putc() instead, so
putc is unused and causes a compile time warning:
In file included from ../arch/arm/boot/compressed/misc.c:28:0:
arch/arm/mach-rpc/include/mach/uncompress.h:79:13: warning: 'putc' defined but not used [-Wunused-function]
arch/arm/mach-w90x900/include/mach/uncompress.h:30:13: warning: 'putc' defined but not used [-Wunused-function]
On most platforms, this does not happen, because putc is defined
as 'static inline' so the compiler will automatically drop it
when it's unused.
This changes the remaining seven platforms to behave the same way.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Almost all architectures define init_new_context() as a function,
but on ARM, it's a macro and that causes a compiler warning when
its return code is not used:
drivers/firmware/efi/arm-runtime.c: In function 'efi_virtmap_init':
arch/arm/include/asm/mmu_context.h:88:34: warning: statement with no effect [-Wunused-value]
#define init_new_context(tsk,mm) 0
drivers/firmware/efi/arm-runtime.c:47:2: note: in expansion of macro 'init_new_context'
init_new_context(NULL, &efi_mm);
This changes the definition into an inline function, which gcc does
not warn about.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
All drivers that are relevant for rpc or footbridge have stopped
using virt_to_bus a while ago, so we can remove it and avoid some
harmless randconfig warnings for drivers that we do not care about:
drivers/atm/zatm.c: In function 'poll_rx':
drivers/atm/zatm.c:401:18: warning: 'bus_to_virt' is deprecated [-Wdeprecated-declarations]
skb = ((struct rx_buffer_head *) bus_to_virt(here[2]))->skb;
FWIW, the remaining drivers using this are:
ATM: firestream, zatm, ambassador, horizon
ISDN: hisax/netjet
V4L: STA2X11, zoran
Net: Appletalk LTPC, Tulip DE4x5, Toshiba IrDA
WAN: comtrol sv11, cosa, lanmedia, sealevel
SCSI: DPT_I2O, buslogic
VME: CA91C142
My best guess is that all of the above are so hopelessly obsolete that
we are best off removing all of them form the kernel, but that can be
done another time.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
With CONFIG_DEBUG_RODATA not being sensible under XIP_KERNEL, remove it
from the XIP linker script.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The __start_rodata_section_aligned is only referenced by the
DEBUG_RODATA code, which is only used when the MMU is enabled,
but the definition fails on !MMU builds:
arch/arm/kernel/vmlinux.lds:702: undefined symbol `SECTION_SHIFT' referenced in expression
This hides the symbol whenever DEBUG_RODATA is disabled.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 64ac2e74f0 ("ARM: 8502/1: mm: mark section-aligned portion of rodata NX")
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When CONFIG_DEBUG_ALIGN_RODATA is set, we get a link error:
arch/arm/mm/built-in.o:(.data+0x4bc): undefined reference to `__start_rodata_section_aligned'
However, this combination is useless, as XIP_KERNEL implies that all the
RODATA is already marked readonly, so both CONFIG_DEBUG_RODATA and
CONFIG_DEBUG_ALIGN_RODATA (which depends on the other) are not
needed with XIP_KERNEL, and this patches enforces that using a Kconfig
dependency.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 25362dc496 ("ARM: 8501/1: mm: flip priority of CONFIG_DEBUG_RODATA")
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARMv6 CPUs do not have virtualisation extensions, but hyp-stub.S is
still included into the image to keep it generic. In order to use ARMv7
instructions during HYP initialisation, add -march=armv7-a flag to
hyp-stub's build.
On an ARMv6 CPU, __hyp_stub_install returns as soon as it detects that
the mode isn't HYP, so we will never reach those instructions.
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The physical-relative calculation between the XIP text and data sections
introduced by the previous patch was far from obvious. Let's simplify it
by turning it into a macro which takes the two (virtual) addresses.
This allows us to arrange the calculation in a more obvious manner - we
can make it two sub-expressions which calculate the physical address for
each symbol, and then takes the difference of those physical addresses.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When XIP_KERNEL is enabled, the virt to phys address translation for RAM
is not the same as the virt to phys address translation for .text.
The only way to know where physical RAM is located is to use
PLAT_PHYS_OFFSET.
The MACRO will be useful for other places where there is a similar problem.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
We can still override these settings via mach/memory.h, but let's provide
sensible defaults so that SPARSEMEM is available in the multiplatform
kernels.
Two platforms currently use SECTION_SIZE_BITS < 28, but are expected to
work with 28 (albeit slightly less efficiently if not all banks are
populated):
- mach-rpc: uses 26 bits. Based on mach/hardware.h it looks like this
platform puts RAM at 0x1000_0000 - 0x1fff_ffff, and I/O below
0x1000_0000.
- mach-sa1100: uses 27 bits. mach/memory.h indicates that RAM occupies
the entire range of 0xc000_0000 - 0xdfff_ffff.
But Arnd says in that rpc and sa1100 will never have to use the
default since they cannot be part of a multiplatform kernel, and that
is unlikely to change.
Several platforms need MAX_PHYSMEM_BITS >= 36 so we'll pick that as the
minimum. Anything higher and we'll fail the SECTIONS_WIDTH + NODES_WIDTH +
ZONES_WIDTH test in <linux/mm.h>.
Some analysis from Russell King at
http://lists.infradead.org/pipermail/linux-arm-kernel/2014-October/298957.html:
I think this is fine in as far as it goes - this means we end up with
256 entries in the mem_section array which means it occupies one page,
which I think is acceptable overhead.
The other thing to be aware of here is the obvious:
#if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
#error Allocator MAX_ORDER exceeds SECTION_SIZE
#endif
Which means that with 28 bits of section, that's a maximum allocator
order of 16. We appear to allow FORCE_MAX_ZONEORDER to be set up to
64 in the case of shmobile, which doesn't seem like a sensible upper
limit - and certainly isn't when sparsemem is enabled.
Given this, I think that FORCE_MAX_ZONEORDER's help, and the
dependencies probably could do with some improvement to make the
issues more transparent.
[gregory.0xf0: added notes from Arnd and Russell]
Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Gregory Fong <gregory.0xf0@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
These two targets were introduced by commit 13d5fadf45 ("[ARM]
Make 'i' and 'zi' targets work") to short-circuit the dependencies
for 'install' and 'zinstall'.
After that, commit 19514fc665 ('arm, kbuild: make "make install"
not depend on vmlinux') eventually made "(z)install" equivalent to
"(z)i".
It is true that 'i' and 'zi' might be still useful as shorthands
but the original intention had been already lost.
They do not even show up in "make ARCH=arm help", so I hope this
deletion does not have much impact.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
"PHONY += FORCE" is already cared by scripts/Makefile.build,
which this file is included from.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARMv8 introduces system registers for the Generic Interrupt Controllers
CPU and virtual interfaces. When GICv3 is implemented, EL2 needs to
allow the kernel to use those registers, by changing the value of
ICC_HSRE.
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When rodata is large enough that it crosses a section boundary after the
kernel text, mark the rest NX. This is as close to full NX of rodata as
we can get without splitting page tables or doing section alignment via
CONFIG_DEBUG_ALIGN_RODATA.
When the config is:
CONFIG_DEBUG_RODATA=y
# CONFIG_DEBUG_ALIGN_RODATA is not set
Before:
---[ Kernel Mapping ]---
0x80000000-0x80100000 1M RW NX SHD
0x80100000-0x80a00000 9M ro x SHD
0x80a00000-0xa0000000 502M RW NX SHD
After:
---[ Kernel Mapping ]---
0x80000000-0x80100000 1M RW NX SHD
0x80100000-0x80700000 6M ro x SHD
0x80700000-0x80a00000 3M ro NX SHD
0x80a00000-0xa0000000 502M RW NX SHD
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
For an XIP build, _etext does not represent the end of the
binary image that needs to stay mapped into the MODULES_VADDR area.
Years ago, data came before text in the memory map. However,
now that the order is text/init/data, an XIP_KERNEL needs to map
up to the data location in order to keep from cutting off
parts of the kernel that are needed.
We only map up to the beginning of data because data has already been
copied, so there's no reason to keep it around anymore.
A new symbol is created to make it clear what it is we are referring
to.
This fixes the bug where you might lose the end of your kernel area
after page table setup is complete.
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit b9b32bf70f ("ARM: use linker magic for vectors and vector stubs")
updated the linker script to emit the .vectors and .stubs sections into a
VMA range that is zero based and disjoint from the normal static kernel
region. The reason for that was that this way, the sections can be placed
exactly 4 KB apart, while the payload of the .vectors section is only 32
bytes.
Since the symbols that are part of the .stubs section are emitted into the
kallsyms table, they appear with zero based addresses as well, e.g.,
00001004 t vector_rst
00001020 t vector_irq
000010a0 t vector_dabt
00001120 t vector_pabt
000011a0 t vector_und
00001220 t vector_addrexcptn
00001240 t vector_fiq
00001240 T vector_fiq_offset
As this confuses perf when it accesses the kallsyms tables, commit
7122c3e915 ("scripts/link-vmlinux.sh: only filter kernel symbols for
arm") implemented a somewhat ugly special case for ARM, where the value
of CONFIG_PAGE_OFFSET is passed to scripts/kallsyms, and symbols whose
addresses are below it are filtered out. Note that this special case only
applies to CONFIG_XIP_KERNEL=n, not because the issue the patch addresses
exists only in that case, but because finding a limit below which to apply
the filtering is not entirely straightforward.
Since the .vectors and .stubs sections contain position independent code
that is never executed in place, we can emit it at its most likely runtime
VMA (for more recent CPUs), which is 0xffff0000 for the vector table and
0xffff1000 for the stubs. Not only does this fix the perf issue with
kallsyms, allowing us to drop the special case in scripts/kallsyms
entirely, it also gives debuggers a more realistic view of the address
space, and setting breakpoints or single stepping through code in the
vector table or the stubs is more likely to work as expected on CPUs that
use a high vector address. E.g.,
00001240 A vector_fiq_offset
...
c0c35000 T __init_begin
c0c35000 T __vectors_start
c0c35020 T __stubs_start
c0c35020 T __vectors_end
c0c352e0 T _sinittext
c0c352e0 T __stubs_end
...
ffff1004 t vector_rst
ffff1020 t vector_irq
ffff10a0 t vector_dabt
ffff1120 t vector_pabt
ffff11a0 t vector_und
ffff1220 t vector_addrexcptn
ffff1240 T vector_fiq
(Note that vector_fiq_offset is now an absolute symbol, which kallsyms
already ignores by default)
The LMA footprint is identical with or without this change, only the VMAs
are different:
Before:
Idx Name Size VMA LMA File off Algn
...
14 .notes 00000024 c0c34020 c0c34020 00a34020 2**2
CONTENTS, ALLOC, LOAD, READONLY, CODE
15 .vectors 00000020 00000000 c0c35000 00a40000 2**1
CONTENTS, ALLOC, LOAD, READONLY, CODE
16 .stubs 000002c0 00001000 c0c35020 00a41000 2**5
CONTENTS, ALLOC, LOAD, READONLY, CODE
17 .init.text 0006b1b8 c0c352e0 c0c352e0 00a452e0 2**5
CONTENTS, ALLOC, LOAD, READONLY, CODE
...
After:
Idx Name Size VMA LMA File off Algn
...
14 .notes 00000024 c0c34020 c0c34020 00a34020 2**2
CONTENTS, ALLOC, LOAD, READONLY, CODE
15 .vectors 00000020 ffff0000 c0c35000 00a40000 2**1
CONTENTS, ALLOC, LOAD, READONLY, CODE
16 .stubs 000002c0 ffff1000 c0c35020 00a41000 2**5
CONTENTS, ALLOC, LOAD, READONLY, CODE
17 .init.text 0006b1b8 c0c352e0 c0c352e0 00a452e0 2**5
CONTENTS, ALLOC, LOAD, READONLY, CODE
...
Acked-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Chris Brandt <chris.brandt@renesas.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Commit b9b32bf70f ("ARM: use linker magic for vectors and vector stubs")
introduced new global definitions of __vectors_start and __stubs_start,
and changed the existing ones to have internal linkage only. However, these
symbols are still visible to kallsyms, and due to the way the .vectors and
.stubs sections are emitted at the base of the VMA space, these duplicate
definitions have conflicting values.
$ nm -n vmlinux |grep -E __vectors|__stubs
00000000 t __vectors_start
00001000 t __stubs_start
c0e77000 T __vectors_start
c0e77020 T __stubs_start
This is completely harmless by itself, since the wrong values are local
symbols that cannot be referenced by other object files directly. However,
since these symbols are also listed in the kallsyms symbol table in some
cases (i.e., CONFIG_KALLSYMS_ALL=y and CONFIG_XIP_KERNEL=y), having these
conflicting values can be confusing. So either remove them, or make them
strictly local.
Acked-by: Chris Brandt <chris.brandt@renesas.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
When building an XIP kernel, the linker script needs to be much different
than a conventional kernel's script. Over time, it's been difficult to
maintain both XIP and non-XIP layouts in one linker script. Therefore,
this patch separates the two procedures into two completely different
files.
The new linker script is essentially a straight copy of the current script
with all the non-CONFIG_XIP_KERNEL portions removed.
Additionally, all CONFIG_XIP_KERNEL portions have been removed from the
existing linker script...never to return again.
It should be noted that this does not fix any current XIP issues, but
rather is the first move in fixing them properly with subsequent patches.
Signed-off-by: Chris Brandt <chris.brandt@renesas.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
ARM64 PSCI kernel interfaces that initialize idle states and implement
the suspend API to enter them are generic and can be shared with the
ARM architecture.
To achieve that goal, this patch moves ARM64 PSCI idle management
code to drivers/firmware, so that the interface to initialize and
enter idle states can actually be shared by ARM and ARM64 arches
back-ends.
The ARM generic CPUidle implementation also requires the definition of
a cpuidle_ops section entry for the kernel to initialize the CPUidle
operations at boot based on the enable-method (ie ARM64 has the
statically initialized cpu_ops counterparts for that purpose); therefore
this patch also adds the required section entry on CONFIG_ARM for PSCI so
that the kernel can initialize the PSCI CPUidle back-end when PSCI is
the probed enable-method.
On ARM64 this patch provides no functional change.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com> [arch/arm64]
Acked-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Jisheng Zhang <jszhang@marvell.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The code enabled by the ARM_CPU_SUSPEND config option is used by
kernel subsystems for purposes that go beyond system suspend so its
config entry should be augmented to take more default options into
account and avoid forcing its selection to prevent dependencies
override.
To achieve this goal, this patch reworks the ARM_CPU_SUSPEND config
entry and updates its default config value (by adding the BL_SWITCHER
option to it) and its dependencies (ARCH_SUSPEND_POSSIBLE), so that the
symbol is still selected by default by the subsystems requiring it and
at the same time enforcing the dependencies correctly.
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If we know that TLB efficiency will not be an issue when memory is
accessed then it's not terribly important to allocate big chunks of
memory. The whole point of allocating the big chunks was that it would
make TLB usage efficient.
As Marek Szyprowski indicated:
Please note that mapping memory with larger pages significantly
improves performance, especially when IOMMU has a little TLB
cache. This can be easily observed when multimedia devices do
processing of RGB data with 90/270 degree rotation
Image rotation is distinctly an operation that needs to bounce around
through memory, so it makes sense that TLB efficiency is important
there.
Video decoding, on the other hand, is a fairly sequential operation.
During video decoding it's not expected that we'll be jumping all over
memory. Decoding video is also pretty heavy and the TLB misses aren't a
huge deal. Presumably most HW video acceleration users of dma-mapping
will not care about huge pages and will set DMA_ATTR_ALLOC_SINGLE_PAGES.
Allocating big chunks of memory is quite expensive, especially if we're
doing it repeadly and memory is full. In one (out of tree) usage model
it is common that arm_iommu_alloc_attrs() is called 16 times in a row,
each one trying to allocate 4 MB of memory. This is called whenever the
system encounters a new video, which could easily happen while the
memory system is stressed out. In fact, on certain social media
websites that auto-play video and have infinite scrolling, it's quite
common to see not just one of these 16x4MB allocations but 2 or 3 right
after another. Asking the system even to do a small amount of extra
work to give us big chunks in this case is just not a good use of time.
Allocating big chunks of memory is also expensive indirectly. Even if
we ask the system not to do ANY extra work to allocate _our_ memory,
we're still potentially eating up all big chunks in the system.
Presumably there are other users in the system that aren't quite as
flexible and that actually need these big chunks. By eating all the big
chunks we're causing extra work for the rest of the system. We also may
start making other memory allocations fail. While the system may be
robust to such failures (as is the case with dwc2 USB trying to allocate
buffers for Ethernet data and with WiFi trying to allocate buffers for
WiFi data), it is yet another big performance hit.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The __iommu_alloc_buffer() is expected to be called to allocate pretty
sizeable buffers. Upon simple tests of video I saw it trying to
allocate 4,194,304 bytes. The function tries to allocate large chunks
in order to optimize IOMMU TLB usage.
The current function is very, very slow.
One problem is the way it keeps trying and trying to allocate big
chunks. Imagine a very fragmented memory that has 4M free but no
contiguous pages at all. Further imagine allocating 4M (1024 pages).
We'll do the following memory allocations:
- For page 1:
- Try to allocate order 10 (no retry)
- Try to allocate order 9 (no retry)
- ...
- Try to allocate order 0 (with retry, but not needed)
- For page 2:
- Try to allocate order 9 (no retry)
- Try to allocate order 8 (no retry)
- ...
- Try to allocate order 0 (with retry, but not needed)
- ...
- ...
Total number of calls to alloc() calls for this case is:
sum(int(math.log(i, 2)) + 1 for i in range(1, 1025))
=> 9228
The above is obviously worse case, but given how slow alloc can be we
really want to try to avoid even somewhat bad cases. I timed the old
code with a device under memory pressure and it wasn't hard to see it
take more than 120 seconds to allocate 4 megs of memory! (NOTE: testing
was done on kernel 3.14, so possibly mainline would behave
differently).
A second problem is that allocating big chunks under memory pressure
when we don't need them is just not a great idea anyway unless we really
need them. We can make due pretty well with smaller chunks so it's
probably wise to leave bigger chunks for other users once memory
pressure is on.
Let's adjust the allocation like this:
1. If a big chunk fails, stop trying to hard and bump down to lower
order allocations.
2. Don't try useless orders. The whole point of big chunks is to
optimize the TLB and it can really only make use of 2M, 1M, 64K and
4K sizes.
We'll still tend to eat up a bunch of big chunks, but that might be the
right answer for some users. A future patch could possibly add a new
DMA_ATTR that would let the caller decide that TLB optimization isn't
important and that we should use smaller chunks. Presumably this would
be a sane strategy for some callers.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Tested-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The tmp variable is used twice: first to pose as a register containing
a value of zero, and then to provide a temporary register that initially
is zero and get added some value. But somehow gcc decides to split those
two usages in different registers.
Example code:
u64 div64const1000(u64 x)
{
u32 y = 1000;
do_div(x, y);
return x;
}
Result:
div64const1000:
push {r4, r5, r6, r7, lr}
mov lr, #0
mov r6, r0
mov r7, r1
adr r5, .L8
ldrd r4, [r5]
mov r1, lr
umull r2, r3, r4, r6
cmn r2, r4
adcs r3, r3, r5
adc r2, lr, #0
umlal r3, r2, r5, r6
umlal r3, r1, r4, r7
mov r3, #0
adds r2, r1, r2
adc r3, r3, #0
umlal r2, r3, r5, r7
lsr r0, r2, #9
lsr r1, r3, #9
orr r0, r0, r3, lsl #23
pop {r4, r5, r6, r7, pc}
.align 3
.L8:
.word -1924145349
.word -2095944041
Full kernel build size:
text data bss dec hex filename
13663814 1553940 351368 15569122 ed90e2 vmlinux
Here the two instances of 'tmp' are assigned to r1 and lr.
To avoid that, let's mark the first 'tmp' usage in __arch_xprod_64()
with a "+r" constraint even if the register is not written to, so to
create a dependency for the second usage with the effect of enforcing
a single temporary register throughout.
Result:
div64const1000:
push {r4, r5, r6, r7}
movs r3, #0
adr r5, .L8
ldrd r4, [r5]
umull r6, r7, r4, r0
cmn r6, r4
adcs r7, r7, r5
adc r6, r3, #0
umlal r7, r6, r5, r0
umlal r7, r3, r4, r1
mov r7, #0
adds r6, r3, r6
adc r7, r7, #0
umlal r6, r7, r5, r1
lsr r0, r6, #9
lsr r1, r7, #9
orr r0, r0, r7, lsl #23
pop {r4, r5, r6, r7}
bx lr
.align 3
.L8:
.word -1924145349
.word -2095944041
text data bss dec hex filename
13663438 1553940 351368 15568746 ed8f6a vmlinux
This time 'tmp' is assigned to r3 and used throughout. However, by being
assigned to r3, that blocks usage of the r2-r3 double register slot for
64-bit values, forcing more registers to be spilled on the stack. Let's
try to help it by forcing 'tmp' to the caller-saved ip register.
Result:
div64const1000:
stmfd sp!, {r4, r5}
mov ip, #0
adr r5, .L8
ldrd r4, [r5]
umull r2, r3, r4, r0
cmn r2, r4
adcs r3, r3, r5
adc r2, ip, #0
umlal r3, r2, r5, r0
umlal r3, ip, r4, r1
mov r3, #0
adds r2, ip, r2
adc r3, r3, #0
umlal r2, r3, r5, r1
mov r0, r2, lsr #9
mov r1, r3, lsr #9
orr r0, r0, r3, asl #23
ldmfd sp!, {r4, r5}
bx lr
.align 3
.L8:
.word -1924145349
.word -2095944041
text data bss dec hex filename
13662838 1553940 351368 15568146 ed8d12 vmlinux
We could make the code marginally smaller yet by forcing 'tmp' to lr
instead, but that would have a negative inpact on branch prediction for
which "bx lr" is optimal.
Signed-off-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The use of CONFIG_DEBUG_RODATA is generally seen as an essential part of
kernel self-protection:
http://www.openwall.com/lists/kernel-hardening/2015/11/30/13
Additionally, its name has grown to mean things beyond just rodata. To
get ARM closer to this, we ought to rearrange the names of the configs
that control how the kernel protects its memory. What was called
CONFIG_ARM_KERNMEM_PERMS is realy doing the work that other architectures
call CONFIG_DEBUG_RODATA.
This redefines CONFIG_DEBUG_RODATA to actually do the bulk of the
ROing (and NXing). In the place of the old CONFIG_DEBUG_RODATA, use
CONFIG_DEBUG_ALIGN_RODATA, since that's what the option does: adds
section alignment for making rodata explicitly NX, as arm does not split
the page tables like arm64 does without _ALIGN_RODATA.
Also adds human readable names to the sections so I could more easily
debug my typos, and makes CONFIG_DEBUG_RODATA default "y" for CPU_V7.
Results in /sys/kernel/debug/kernel_page_tables for each config state:
# CONFIG_DEBUG_RODATA is not set
# CONFIG_DEBUG_ALIGN_RODATA is not set
---[ Kernel Mapping ]---
0x80000000-0x80900000 9M RW x SHD
0x80900000-0xa0000000 503M RW NX SHD
CONFIG_DEBUG_RODATA=y
CONFIG_DEBUG_ALIGN_RODATA=y
---[ Kernel Mapping ]---
0x80000000-0x80100000 1M RW NX SHD
0x80100000-0x80700000 6M ro x SHD
0x80700000-0x80a00000 3M ro NX SHD
0x80a00000-0xa0000000 502M RW NX SHD
CONFIG_DEBUG_RODATA=y
# CONFIG_DEBUG_ALIGN_RODATA is not set
---[ Kernel Mapping ]---
0x80000000-0x80100000 1M RW NX SHD
0x80100000-0x80a00000 9M ro x SHD
0x80a00000-0xa0000000 502M RW NX SHD
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Laura Abbott <labbott@fedoraproject.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Code run via soft_restart() is run with the MMU disabled, so we need to
pass the identity map physical address rather than the address obtained
from virt_to_phys(). Therefore, replace virt_to_phys() with
virt_to_idmap() for all callers of soft_restart().
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Make virt_to_idmap() return an unsigned long rather than phys_addr_t.
Returning phys_addr_t here makes no sense, because the definition of
virt_to_idmap() is that it shall return a physical address which maps
identically with the virtual address. Since virtual addresses are
limited to 32-bit, identity mapped physical addresses are as well.
Almost all users already had an implicit narrowing cast to unsigned long
so let's make this official and part of this interface.
Tested-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
arm: irq: l2c: do not print error in case of missing l2c from dtb
In some architectures the L2 cache controller is integrated in the
processor's block itself and it doesn't use any external cache
controller. This means that an entry in the board's dtb related
to the l2c is not necessary.
Distinguish between error codes and do not print anything in case
l2x0_of_init() doesn't find any L2C DTB entry and returns -ENODEV.
This patch mutes the following error message:
L2C: failed to init: -19
on boards like odroid-xu4, cortex A7/A15, which don't have
external cache controller.
Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Reported-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Instead of looping through all cpus calling set_capacity_scale, we can
initialise cpu_scale per-cpu variables to SCHED_CAPACITY_SCALE with their
definition.
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Implement an ARM delay timer to be used for udelay() on orion legacy
platforms. This allows us to skip the delay loop calibration at boot.
It also means that udelay() will be unaffected by CPU frequency changes
when cpufreq is enabled on these platforms.
Tested-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Pull MIPS updates from Ralf Baechle:
"This is the main pull request for MIPS for 4.5 plus some 4.4 fixes.
The executive summary:
- ATH79 platform improvments, use DT bindings for the ATH79 USB PHY.
- Avoid useless rebuilds for zboot.
- jz4780: Add NEMC, BCH and NAND device tree nodes
- Initial support for the MicroChip's DT platform. As all the device
drivers are missing this is still of limited use.
- Some Loongson3 cleanups.
- The unavoidable whitespace polishing.
- Reduce clock skew when synchronizing the CPU cycle counters on CPU
startup.
- Add MIPS R6 fixes.
- Lots of cleanups across arch/mips as fallout from KVM.
- Lots of minor fixes and changes for IEEE 754-2008 support to the
FPU emulator / fp-assist software.
- Minor Ralink, BCM47xx and bcm963xx platform support improvments.
- Support SMP on BCM63168"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (84 commits)
MIPS: zboot: Add support for serial debug using the PROM
MIPS: zboot: Avoid useless rebuilds
MIPS: BMIPS: Enable ARCH_WANT_OPTIONAL_GPIOLIB
MIPS: bcm63xx: nvram: Remove unused bcm63xx_nvram_get_psi_size() function
MIPS: bcm963xx: Update bcm_tag field image_sequence
MIPS: bcm963xx: Move extended flash address to bcm_tag header file
MIPS: bcm963xx: Move Broadcom BCM963xx image tag data structure
MIPS: bcm63xx: nvram: Use nvram structure definition from header file
MIPS: bcm963xx: Add Broadcom BCM963xx board nvram data structure
MAINTAINERS: Add KVM for MIPS entry
MIPS: KVM: Add missing newline to kvm_err()
MIPS: Move KVM specific opcodes into asm/inst.h
MIPS: KVM: Use cacheops.h definitions
MIPS: Break down cacheops.h definitions
MIPS: Use EXCCODE_ constants with set_except_vector()
MIPS: Update trap codes
MIPS: Move Cause.ExcCode trap codes to mipsregs.h
MIPS: KVM: Make kvm_mips_{init,exit}() static
MIPS: KVM: Refactor added offsetof()s
MIPS: KVM: Convert EXPORT_SYMBOL to _GPL
...
As most platforms implement the PROM serial interface prom_putchar()
add a simple bridge to allow re-using this code for zboot.
Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11811/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add dummy.o to the targets list, and fill targets automatically from
$(vmlinuzobjs) to avoid having to maintain two lists.
When building with XZ compression copy ashldi3.c to the build
directory to use a different object file for the kernel and zboot.
Without this the same object file need to be build with different
flags which cause a rebuild at every run.
Signed-off-by: Alban Bedel <albeu@free.fr>
Cc: linux-mips@linux-mips.org
Cc: Alex Smith <alex.smith@imgtec.com>
Cc: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11810/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Remove bcm63xx_nvram_get_psi_size() as it now has no users.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11836/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Move Broadcom BCM963xx image tag data structure to include/linux/
so that drivers outside of mach-bcm63xx can use it.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11832/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Use the common definition of the nvram structure from the header file
include/linux/bcm963xx_nvram.h instead of maintaining a separate copy.
Read the version 5 size of nvram data from memory and then call the
new checksum verification function from the header file.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Brian Norris <computersforpeace@gmail.com>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: MIPS Mailing List <linux-mips@linux-mips.org>
Cc: MTD Maling List <linux-mtd@lists.infradead.org>
Patchwork: https://patchwork.linux-mips.org/patch/11831/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The header arch/mips/kvm/opcode.h defines a few extra opcodes which
aren't in arch/mips/include/uapi/asm/inst.h. There's nothing KVM
specific about them, so lets move them into inst.h where they belong and
delete the header.
Note that mfmcz_op is renamed to mfmc0_op to match the instruction set
manual, and wait_op was already added to inst.h in commit b0a3eae2b9
("MIPS: inst.h: define COP0 wait op"), merged in v3.16-rc1.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11895/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Drop the custom cache operation code definitions used by KVM for
emulating guest CACHE instructions, and switch to use the existing
definitions in <asm/cacheops.h>.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11893/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Most of the cache op codes defined in cacheops.h are split into a 2-bit
cache identifier, and a 3-bit cache op code which does largely the same
thing semantically regardless of the cache identifier.
To allow the use of these definitions by KVM for decoding cache ops,
break the definitions down into parts where it makes sense to do so, and
add masks for the Cache and Op field within the cache op.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11892/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The first argument to set_except_vector is the ExcCode, which we now
have definitions for. Lets make use of them.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11894/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add a few missing trap codes.
[ralf@linux-mips.org: Drop removal of exception codes. I don't care what
the incomplete architecture spec says; it can't change existing hardware
and VCEI is supported indeed.]
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11890/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Move the Cause.ExcCode trap code definitions from kvm_host.h to
mipsregs.h, since they describe architectural bits rather than KVM
specific constants, and change the prefix from T_ to EXCCODE_.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11891/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The module init and exit functions have no need to be global, so make
them static.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: kvm@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11889/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When calculating the offsets into the commpage for dynamically
translated mtc0/mfc0 guest instructions, multiple offsetof()s are added
together to find the offset of the specific register in the mips_coproc,
within the commpage.
Simplify each of these cases to a single offsetof() to find the offset
of the specific register within the commpage.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11888/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Export symbols only to GPL modules to match other KVM symbols in
virt/kvm/ and arch/*/kvm/.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11887/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The function kvm_mips_host_tlb_inv_index() is unused, so drop it
completely.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11886/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The CAUSEB_DC and CAUSEF_DC definitions used by KVM are defined in
asm/kvm_host.h, but all the other Cause register field definitions are
found in asm/mipsregs.h.
Lets reunite the DC bit definitions with its friends in mipsregs.h.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11885/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
