Fix incorrect calculation in do_monotonic() and do_monotonic_coarse()
function that in turn caused incorrect values returned by the vdso
version of system call clock_gettime() on mips64 if its system clock
ID parameter was CLOCK_MONOTONIC or CLOCK_MONOTONIC_COARSE.
Consider these variables and their types on mips32 and mips64:
tk->wall_to_monotonic.tv_sec s64, s64 (kernel/vdso.c)
vdso_data.wall_to_mono_sec u32, u32 (kernel/vdso.c)
to_mono_sec u32, u32 (vdso/gettimeofday.c)
ts->tv_sec s32, s64 (vdso/gettimeofday.c)
For mips64 case, u32 vdso_data.wall_to_mono_sec variable is updated
from the 64-bit signed variable tk->wall_to_monotonic.tv_sec
(kernel/vdso.c:76) which is a negative number holding the time passed
from 1970-01-01 to the time boot started. This 64-bit signed value is
currently around 47+ years, in seconds. For instance, let this value
be:
-1489757461
or
11111111111111111111111111111111 10100111001101000001101011101011
By updating 32-bit vdso_data.wall_to_mono_sec variable, we lose upper
32 bits (signed 1's).
to_mono_sec variable is a parameter of do_monotonic() and
do_monotonic_coarse() functions which holds vdso_data.wall_to_mono_sec
value. Its value needs to be added (or subtracted considering it holds
negative value from the tk->wall_to_monotonic.tv_sec) to the current
time passed from 1970-01-01 (ts->tv_sec), which is again something like
47+ years, but increased by the time passed from the boot to the
current time. ts->tv_sec is 32-bit long in case of 32-bit architecture
and 64-bit long in case of 64-bit architecture. Consider the update of
ts->tv_sec (vdso/gettimeofday.c:55 & 167):
ts->tv_sec += to_mono_sec;
mips32 case: This update will be performed correctly, since both
ts->tv_sec and to_mono_sec are 32-bit long and the sign in to_mono_sec
is preserved. Implicit conversion from u32 to s32 will be done
correctly.
mips64 case: This update will be wrong, since the implicit conversion
will not be done correctly. The reason is that the conversion will be
from u32 to s64. This is because to_mono_sec is 32-bit long for both
mips32 and mips64 cases and s64..33 bits of converted to_mono_sec
variable will be zeros.
So, in order to make MIPS64 implementation work properly for
MONOTONIC and MONOTONIC_COARSE clock ids on mips64, the size of
wall_to_mono_sec variable in mips_vdso_data union and respective
parameters in do_monotonic() and do_monotonic_coarse() functions
should be changed from u32 to u64. Because of consistency, this
size change from u32 and u64 is also done for wall_to_mono_nsec
variable and corresponding function parameters.
As far as similar situations for other architectures are concerned,
let's take a look at arm. Arm has two distinct vdso_data structures
for 32-bit & 64-bit cases, and arm's wall_to_mono_sec and
wall_to_mono_nsec are u32 for 32-bit and u64 for 64-bit cases.
On the other hand, MIPS has only one structure (mips_vdso_data),
hence the need for changing the size of above mentioned parameters.
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: Douglas Leung <douglas.leung@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Petar Jovanovic <petar.jovanovic@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16638/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 8ec7f15b8c)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Add "-modd-spreg" when compiling the kernel for mips32r6 target.
This makes sure the kernel builds properly even with toolchains that
use "-mno-odd-spreg" by default. This is the case with Android gcc.
Prior to this patch, kernel builds using gcc for Android failed with
following error messages, if target architecture is set to mips32r6:
arch/mips/kernel/r4k_switch.S: Assembler messages:
.../r4k_switch.S:210: Error: float register should be even, was 1
.../r4k_switch.S:212: Error: float register should be even, was 3
.../r4k_switch.S:214: Error: float register should be even, was 5
.../r4k_switch.S:216: Error: float register should be even, was 7
.../r4k_switch.S:218: Error: float register should be even, was 9
.../r4k_switch.S:220: Error: float register should be even, was 11
.../r4k_switch.S:222: Error: float register should be even, was 13
.../r4k_switch.S:224: Error: float register should be even, was 15
.../r4k_switch.S:226: Error: float register should be even, was 17
.../r4k_switch.S:228: Error: float register should be even, was 19
.../r4k_switch.S:230: Error: float register should be even, was 21
.../r4k_switch.S:232: Error: float register should be even, was 23
.../r4k_switch.S:234: Error: float register should be even, was 25
.../r4k_switch.S:236: Error: float register should be even, was 27
.../r4k_switch.S:238: Error: float register should be even, was 29
.../r4k_switch.S:240: Error: float register should be even, was 31
make[2]: *** [arch/mips/kernel/r4k_switch.o] Error 1
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: James.Hogan@imgtec.com
Cc: Paul.Burton@imgtec.com
Cc: Raghu.Gandham@imgtec.com
Cc: Leonid.Yegoshin@imgtec.com
Cc: Douglas.Leung@imgtec.com
Cc: Petar.Jovanovic@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16509/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 21855a6e5b)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Implement support for parsing 'memmap' kernel command line parameter.
This patch covers parsing of the following two formats for 'memmap'
parameter values:
- nn[KMG]@ss[KMG]
- nn[KMG]$ss[KMG]
([KMG] = K M or G (kilo, mega, giga))
These two allowed formats for parameter value are already documented
in file kernel-parameters.txt in Documentation/admin-guide folder.
Some architectures already support them, but Mips did not prior to
this patch.
Excerpt from Documentation/admin-guide/kernel-parameters.txt:
memmap=nn[KMG]@ss[KMG]
[KNL] Force usage of a specific region of memory.
Region of memory to be used is from ss to ss+nn.
memmap=nn[KMG]$ss[KMG]
Mark specific memory as reserved.
Region of memory to be reserved is from ss to ss+nn.
Example: Exclude memory from 0x18690000-0x1869ffff
memmap=64K$0x18690000
or
memmap=0x10000$0x18690000
There is no need to update this documentation file with respect to
this patch.
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: Goran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtec.com>
Cc: James.Hogan@imgtec.com
Cc: Paul.Burton@imgtec.com
Cc: Raghu.Gandham@imgtec.com
Cc: Leonid.Yegoshin@imgtec.com
Cc: Douglas.Leung@imgtec.com
Cc: Petar.Jovanovic@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16508/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 296a7624f5)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
On some MIPS systems, a subset of devices may have DMA coherent with CPU
caches. For example in systems including a MIPS I/O Coherence Unit
(IOCU), some devices may be connected to that IOCU whilst others are
not.
Prior to this patch, we have a plat_device_is_coherent() function but no
implementation which does anything besides return a global true or
false, optionally chosen at runtime. For devices such as those described
above this is insufficient.
Fix this by tracking DMA coherence on a per-device basis with a
dma_coherent field in struct dev_archdata. Setting this from
arch_setup_dma_ops() takes care of devices which set the dma-coherent
property via device tree, and any PCI devices beneath a bridge described
in DT, automatically.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14349/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 20d330645c)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
There are no cases where plat_device_is_coherent() will return zero
whilst hw_coherentio is non-zero, and acting any differently in such a
case doesn't make much sense - if a device is non-coherent with the CPU
caches then access to memory "coherent" with DMA must be uncached. Clean
up the nonsensical case.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14348/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit cfa93fb9c2)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
The coherentio variable has previously been used as a boolean value,
indicating whether the user specified that coherent I/O should be
enabled or disabled. It failed to take into account the case where the
user does not specify any preference, in which case it makes sense that
we should default to coherent I/O if the hardware supports it
(hw_coherentio is non-zero).
Introduce an enum to clarify the 3 different values of coherentio & use
it throughout the code, modifying plat_device_is_coherent() &
r4k_cache_init() to take into account the default case.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Paul Burton <paul.burton@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/14347/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit f23020230e)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Provide a default implementation of mips_cpc_default_phys_base() which
simply returns 0, and adjust mips_cpc_phys_base() to allow for
mips_cpc_default_phys_base() returning 0. This allows kernels which
include CPC support to be built without platform code & simply ignore
the CPC if it wasn't already enabled by the bootloader.
This fixes link failures such as the following from generic defconfigs:
arch/mips/built-in.o: In function `mips_cpc_phys_base':
arch/mips/kernel/mips-cpc.c:47: undefined reference to `mips_cpc_default_phys_base'
[ralf@linux-mips.org: changed prototype for coding style compliance.]
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14401/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 682c1e5221)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Introduce a "generic" platform, which aims to be board-agnostic by
making use of device trees passed by the boot protocol defined in the
MIPS UHI (Universal Hosting Interface) specification. Provision is made
for supporting boards which use a legacy boot protocol that can't be
changed, but adding support for such boards or any others is left to
followon patches.
Right now the built kernels expect to be loaded to 0x80100000, ie. in
kseg0. This is fine for the vast majority of MIPS platforms, but
nevertheless it would be good to remove this limitation in the future by
mapping the kernel via the TLB such that it can be loaded anywhere & map
itself appropriately.
Configuration is handled by dynamically generating configs using
scripts/kconfig/merge_config.sh, somewhat similar to the way powerpc
makes use of it. This allows for variations upon the configuration, eg.
differing architecture revisions or subsets of driver support for
differing boards, to be handled without having a large number of
defconfig files.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14353/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit eed0eabd12)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Add support for generating kernel images in the Flattened Image Tree
(.itb) format as supported by U-Boot. This format is essentially a
Flattened Device Tree binary containing images (kernels, DTBs, ramdisks)
and configurations which link those images together. The big advantages
of FIT images over the uImage format are:
- We can include FDTs in the kernel image in a way that the bootloader
can extract it & manipulate it before providing it to the kernel.
Thus we can ship FDTs as part of the kernel giving us the advantages
of being able to develop & maintain the DT within the kernel tree,
but also have the benefits of the bootloader being able to
manipulate the FDT. Example uses for this would be to inject the
kernel command line into the chosen node, or to fill in the correct
memory size.
- We can include multiple configurations in a single kernel image.
This means that a single FIT image can, given appropriate
bootloaders, be booted on different boards with the bootloader
selecting an appropriate configuration & providing the correct FDT
to the kernel.
- We can support a multitude of hashes over the data.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14352/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit cf2a5e0bb4)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Fix the problem of inaccurate identification of instructions BLEZL and
BGTZL in R2 emulation code by making sure all necessary encoding
specifications are met.
Previously, certain R6 instructions could be identified as BLEZL or
BGTZL. R2 emulation routine didn't take into account that both BLEZL
and BGTZL instructions require their rt field (bits 20 to 16 of
instruction encoding) to be 0, and that, at same time, if the value in
that field is not 0, the encoding may represent a legitimate MIPS R6
instruction.
This means that a problem could occur after emulation optimization,
when emulation routine tried to pipeline emulation, picked up a next
candidate, and subsequently misrecognized an R6 instruction as BLEZL
or BGTZL.
It should be said that for single pass strategy, the problem does not
happen because CPU doesn't trap on branch-compacts which share opcode
space with BLEZL/BGTZL (but have rt field != 0, of course).
Signed-off-by: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Signed-off-by: Miodrag Dinic <miodrag.dinic@imgtech.com>
Signed-off-by: Aleksandar Markovic <aleksandar.markovic@imgtech.com>
Reported-by: Douglas Leung <douglas.leung@imgtec.com>
Reviewed-by: Paul Burton <paul.burton@imgtec.com>
Cc: james.hogan@imgtec.com
Cc: petar.jovanovic@imgtec.com
Cc: goran.ferenc@imgtec.com
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15456/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 5bba7aa495)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Sanitize FCSR Cause bit handling, following a trail of past attempts:
* commit 4249548454 ("MIPS: ptrace: Fix FP context restoration FCSR
regression"),
* commit 443c44032a ("MIPS: Always clear FCSR cause bits after
emulation"),
* commit 64bedffe49 ("MIPS: Clear [MSA]FPE CSR.Cause after
notify_die()"),
* commit b1442d39fa ("MIPS: Prevent user from setting FCSR cause
bits"),
* commit b54d2901517d ("Properly handle branch delay slots in connection
with signals.").
Specifically do not mask these bits out in ptrace(2) processing and send
a SIGFPE signal instead whenever a matching pair of an FCSR Cause and
Enable bit is seen as execution of an affected context is about to
resume. Only then clear Cause bits, and even then do not clear any bits
that are set but masked with the respective Enable bits. Adjust Cause
bit clearing throughout code likewise, except within the FPU emulator
proper where they are set according to IEEE 754 exceptions raised as the
operation emulated executed. Do so so that any IEEE 754 exceptions
subject to their default handling are recorded like with operations
executed by FPU hardware.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14460/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 5a1aca4469)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends. That changed
when we forked out support for the latter into the export.h file.
This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig. The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.
Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace as needed.
In the case of the n32/o32 files, we have to get rid of a couple
no-op MODULE_ tags to facilitate the module.h removal. They piggy
back off the fs/ elf binary support, which is also a bool Kconfig.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14032/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit d9d5417755)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Fix r4k_flush_cache_sigtramp() and local_r4k_flush_cache_sigtramp() to
flush the delay slot emulation trampoline cacheline through a kmap
rather than directly when the active_mm doesn't match that of the task
initiating the flush, a bit like local_r4k_flush_cache_page() does.
This would fix a corner case on SMP systems without hardware globalized
hit cache ops, where a migration to another CPU after the flush, where
that CPU did not have the same mm active at the time of the flush, could
result in stale icache content being executed instead of the trampoline,
e.g. from a previous delay slot emulation with a similar stack pointer.
This case was artificially triggered by replacing the icache flush with
a full indexed flush (not globalized on CM systems) and forcing the SMP
call to take place, with a test program that alternated two FPU delay
slots with a parent process repeatedly changing scheduler affinity.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13797/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit e523f289fe)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
The protected_writeback_scache_line() function is used by
local_r4k_flush_cache_sigtramp() to flush an FPU delay slot emulation
trampoline on the userland stack from the caches so it is visible to
subsequent instruction fetches.
Commit de8974e3f7 ("MIPS: asm: r4kcache: Add EVA cache flushing
functions") updated some protected_ cache flush functions to use EVA
CACHEE instructions via protected_cachee_op(), and commit 83fd43449b
("MIPS: r4kcache: Add EVA case for protected_writeback_dcache_line") did
the same thing for protected_writeback_dcache_line(), but
protected_writeback_scache_line() never got updated. Lets fix that now
to flush the right user address from the secondary cache rather than
some arbitrary kernel unmapped address.
This issue was spotted through code inspection, and it seems unlikely to
be possible to hit this in practice. It theoretically affect EVA kernels
on EVA capable cores with an L2 cache, where the icache fetches straight
from RAM (cpu_icache_snoops_remote_store == 0), running a hard float
userland with FPU disabled (nofpu). That both Malta and Boston platforms
override cpu_icache_snoops_remote_store to 1 suggests that all MIPS
cores fetch instructions into icache straight from L2 rather than RAM.
Fixes: de8974e3f7 ("MIPS: asm: r4kcache: Add EVA cache flushing functions")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13800/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 0758b116b4)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Follow our own rules set in <asm/siginfo.h> for SIGTRAP signals issued
from `do_watch' and `do_trap_or_bp' by setting the signal code to
TRAP_HWBKPT and TRAP_BRKPT respectively, for Watch exceptions and for
those Breakpoint exceptions whose originating BREAK instruction's code
does not have a special meaning. Keep Trap exceptions unaffected as
these are not debug events.
No existing user software is expected to examine signal codes for these
signals as SI_KERNEL has been always used here. This change makes the
MIPS port more like other Linux ports, which reduces the complexity and
provides for performance improvement in GDB.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Luis Machado <lgustavo@codesourcery.com>
Cc: linux-mips@linux-mips.org
Cc: gdb@sourceware.org
Patchwork: https://patchwork.linux-mips.org/patch/12758/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 3b143cca6e)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
The opcodes currently defined in inst.h as cbcond0_op & cbcond1_op are
actually defined in the MIPS base instruction set manuals as pop10 &
pop30 respectively. Rename them as such, for consistency with the
documentation.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 1b49260006)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
The opcodes currently defined in inst.h as beqzcjic_op & bnezcjialc_op
are actually defined in the MIPS base instruction set manuals as pop66 &
pop76 respectively. Rename them as such, for consistency with the
documentation.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 1c66b79bb3)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
The code in _sp_maddf (formerly ieee754sp_madd) appears to have been
copied verbatim from ieee754sp_add, and although it's adding the
unpacked "r" & "z" floats it kept using macros that operate on "x" &
"y". This led to the addition being carried out incorrectly on some
mismash of the product, accumulator & multiplicand fields. Typically
this would lead to the assertions "ze == re" & "ze <= SP_EMAX" failing
since ze & re hadn't been operated upon.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Fixes: e24c3bec3e ("MIPS: math-emu: Add support for the MIPS R6 MADDF FPU instruction")
Cc: Adam Buchbinder <adam.buchbinder@gmail.com>
Cc: Maciej W. Rozycki <macro@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13159/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit db57f29d50)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
A comment in ieee754dp_mul indicates that the code is about to perform a
32b x 32b multiplication & keep the high 32b of the result. It appears
this was copied from the single-precision multiplication code, since the
code actually goes on to perform a 64b x 64b multiplication & keep the
high 64b of the result. Fix the comment to indicate 64b.
It appears also that this comment was copied verbatim along with the
rest of the multiplication code into ieee754dp_maddf, which has since
been renamed _dp_maddf. Fix the same issue there.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13157/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 95bff2410c)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
The code for emulating MIPSr6 madd.d & msub.d instructions has
previously been implemented as 2 different functions, namely
ieee754dp_maddf & ieee754dp_msubf. The difference in behaviour of these
2 instructions is merely the sign of the product, so we can easily share
the code implementing them. Do this for the double precision variant,
removing the original ieee754dp_msubf in favor of reusing the code from
ieee754dp_maddf.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13155/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit d728f6709b)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
The code for emulating MIPSr6 madd.s & msub.s instructions has
previously been implemented as 2 different functions, namely
ieee754sp_maddf & ieee754sp_msubf. The difference in behaviour of these
2 instructions is merely the sign of the product, so we can easily share
the code implementing them. Do this for the single precision variant,
removing the original ieee754sp_msubf in favor of reusing the code from
ieee754sp_maddf.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13154/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 6162051e87)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Propagate sNaN payload in quieting in the legacy-NaN mode as well. If
clearing the quiet bit would produce infinity, then set the next lower
trailing significand field bit, matching the SB-1 and BMIPS5000 hardware
implementations. Some other MIPS FPU hardware implementations do
produce the default qNaN bit pattern instead.
This reverts some changes made for semantics preservation with commit
dc3ddf42 [MIPS: math-emu: Update sNaN quieting handlers], consequently
bringing back most of the semantics from before commit fdffbafb [Lots of
FPU bug fixes from Kjeld Borch Egevang.], except from the qNaN produced
in the infinity case. Previously the default qNaN bit pattern was
produced in that case.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11483/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit acd9e20cd9)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Implement IEEE Std 754-2008 NaN encoding wired to the state of the
FCSR.NAN2008 bit. Make the interpretation of the quiet bit in NaN data
as follows:
* in the legacy mode originally defined by the MIPS architecture the
value of 1 denotes an sNaN whereas the value of 0 denotes a qNaN,
* in the 2008 mode introduced with revision 5 of the MIPS architecture
the value of 0 denotes an sNaN whereas the value of 1 denotes a qNaN,
following the definition of the preferred NaN encoding introduced with
IEEE Std 754-2008.
In the 2008 mode, following the requirement of the said standard, quiet
an sNaN where needed by setting the quiet bit to 1 and leaving all the
NaN payload bits unchanged.
Update format conversion operations according to the rules set by IEEE
Std 754-2008 and the MIPS architecture. Specifically:
* propagate NaN payload bits through conversions between floating-point
formats such that as much information as possible is preserved and
specifically a conversion from a narrower format to a wider format and
then back to the original format does not change a qNaN payload in any
way,
* conversions from a floating-point to an integer format where the
source is a NaN, infinity or a value that would convert to an integer
outside the range of the result format produce, under the default
exception handling, the respective values defined by the MIPS
architecture.
In full FPU emulation set the FIR.HAS2008 bit to 1, however do not make
any further FCSR bits writable.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11477/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 90d53a91fb)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
The stack and heap have both been executable by default on MIPS until
now. This patch changes the default to be non-executable, but only for
ELF binaries with a non-executable PT_GNU_STACK header present. This
does apply to both the heap & the stack, despite the name PT_GNU_STACK,
and this matches the behaviour of other architectures like ARM & x86.
Current MIPS toolchains do not produce the PT_GNU_STACK header, which
means that we can rely upon this patch not changing the behaviour of
existing binaries. The new default will only take effect for newly
compiled binaries once toolchains are updated to support PT_GNU_STACK,
and since those binaries are newly compiled they can be compiled
expecting the change in default behaviour. Again this matches the way in
which the ARM & x86 architectures handled their implementations of
non-executable memory.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Leonid Yegoshin <leonid.yegoshin@imgtec.com>
Cc: Maciej Rozycki <maciej.rozycki@imgtec.com>
Cc: Faraz Shahbazker <faraz.shahbazker@imgtec.com>
Cc: Raghu Gandham <raghu.gandham@imgtec.com>
Cc: Matthew Fortune <matthew.fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13765/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 1a770b85c1)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Add an `ieee754=' kernel parameter to control IEEE Std 754 conformance
mode.
Use separate flags copied from the respective CPU feature flags, and
adjusted according to the conformance mode selected, to make binaries
requesting individual NaN encoding modes accepted or rejected as needed.
Update the initial setting for FCSR and, in the full FPU emulation mode,
its read-only mask accordingly. Accept the mode selection requested for
legacy processors as well.
As with the EF_MIPS_NAN2008 ELF file header flag adjust both ABS2008 and
NAN2008 bits at the same time, to match the choice made for hardware
currently implemented.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11481/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 503943e0e5)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Determine the presence of and the amount of control available over IEEE
Std 754-2008 features.
In the case of a hardware FPU being used examine the FIR register for
the presence of the HAS2008 bit and then the FCSR register for the
writability of the ABS2008 and NAN2008 bits and the hardwired state of
each of these bits if read-only. Update the initial FCSR contents used
for threads and the FCSR writability mask accordingly.
For full FPU emulation and MIPS32 or MIPS64 processors make the FCSR
ABS2008 and NAN2008 bits writable.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11480/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 93adeaf6da)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Handle the EF_MIPS_NAN2008 ELF file header flag and refuse execution
where there is no support in the FPU for the NaN encoding mode requested
by a binary invoked. Ensure that the setting of the bit in the binary
matches one in any intepreter used. Set the thread's initial FCSR
contents according to the value of the EF_MIPS_NAN2008.
Set the values of the FCSR ABS2008 and NAN2008 bits both to the same
value if possible, to take the approach taken with existing FPU hardware
into account. As of now all implementations have both bits hardwired to
the same value, that is both are fixed at 0 or both are fixed at 1, even
though the architecture allows for implementations where the amount of
control implemented with each of these two individual bits is
independent of each other.
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Matthew Fortune <Matthew.Fortune@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/11479/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
(cherry picked from commit 2b5e869ecf)
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
