The comment describing the loongson_llsc_mb() reorder case doesn't
make any sense what so ever. Instruction re-ordering is not an SMP
artifact, but rather a CPU local phenomenon. Clarify the comment by
explaining that these issue cause a coherence fail.
For the branch speculation case; if futex_atomic_cmpxchg_inatomic()
needs one at the bne branch target, then surely the normal
__cmpxch_asm() implementation does too. We cannot rely on the
barriers from cmpxchg() because cmpxchg_local() is implemented with
the same macro, and branch prediction and speculation are, too, CPU
local.
Fixes: e02e07e312 ("MIPS: Loongson: Introduce and use loongson_llsc_mb()")
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Huang Pei <huangpei@loongson.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
There were no memory barriers on the 32bit implementation of
cmpxchg64(). Fix this.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Break up the big ioc3 register struct into functional pieces to
make use in sub-function drivers more straightforward. And while
doing that get rid of all volatile access by using readX/writeX.
Signed-off-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on an email from Paul Burton, quoting section 4.8 "Cacheability and
Coherency Attributes and Access Types" of "MIPS Architecture Volume 1:
Introduction to the MIPS32 Architecture" (MD00080, revision 6.01).
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Paul Burton <paul.burton@mips.com>
arch_dma_mmap_pgprot is used for two things:
1) to override the "normal" uncached page attributes for mapping
memory coherent to devices that can't snoop the CPU caches
2) to provide the special DMA_ATTR_WRITE_COMBINE semantics on older
arm systems and some mips platforms
Replace one with the pgprot_dmacoherent macro that is already provided
by arm and much simpler to use, and lift the DMA_ATTR_WRITE_COMBINE
handling to common code with an explicit arch opt-in.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> # m68k
Acked-by: Paul Burton <paul.burton@mips.com> # mips
We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.
// <smpl>
@@
expression ret;
struct platform_device *E;
@@
ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);
if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>
While we're here, remove braces on if statements that only have one
statement (manually).
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-kernel@vger.kernel.org
The code in question is modifying a variable declared const through
pointer manipulation. Such code is explicitly undefined behavior, and
is the lone issue preventing malta_defconfig from booting when built
with Clang:
If an attempt is made to modify an object defined with a const-qualified
type through use of an lvalue with non-const-qualified type, the
behavior is undefined.
LLVM is removing such assignments. A simple fix is to not declare
variables const that you plan on modifying. Limiting the scope would be
a better method of preventing unwanted writes to such a variable.
Further, the code in question mentions "compiler bugs" without any links
to bug reports, so it is difficult to know if the issue is resolved in
GCC. The patch was authored in 2006, which would have been GCC 4.0.3 or
4.1.1. The minimal supported version of GCC in the Linux kernel is
currently 4.6.
For what its worth, there was UB before the commit in question, it just
added a barrier and got lucky IRT codegen. I don't think there's any
actual compiler bugs related, just runtime bugs due to UB.
Link: https://github.com/ClangBuiltLinux/linux/issues/610
Fixes: 966f4406d9 ("[MIPS] Work around bad code generation for <asm/io.h>.")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Debugged-by: Nathan Chancellor <natechancellor@gmail.com>
Suggested-by: Eli Friedman <efriedma@quicinc.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: ralf@linux-mips.org
Cc: jhogan@kernel.org
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: Hassan Naveed <hnaveed@wavecomp.com>
Cc: Stephen Kitt <steve@sk2.org>
Cc: Serge Semin <fancer.lancer@gmail.com>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: clang-built-linux@googlegroups.com
Commit a94e4f24ec ("MIPS: init: Drop boot_mem_map") introduced a
reference to a non-existant "end" field in struct memblock_region.
Replace it with a sum of the base & size fields to fix builds with
CONFIG_PROC_VMCORE=y.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Commit a5718fe8f7 ("MIPS: mm: Drop boot_mem_map") removed the
definition of a page variable for some reason, but that variable is
still used. Restore it to fix compilation with CONFIG_HIGHMEM enabled.
Signed-off-by: Paul Burton <paul.burton@mips.com>
boot_mem_map was introduced very early and cannot handle memory maps
with nid. Nowadays, memblock can exactly replace boot_mem_map.
Detect pfn info and setup resources with memblock maps.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
[paul.burton@mips.com: Fix size calculation in check_kernel_sections_mem]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: yasha.che3@gmail.com
Cc: aurelien@aurel32.net
Cc: sfr@canb.auug.org.au
Cc: fancer.lancer@gmail.com
Cc: matt.redfearn@mips.com
Cc: chenhc@lemote.com
Initialize maar by resource map and replace page_is_ram
by memblock_is_memory.
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
[paul.burton@mips.com:
- Fix bad MAAR address calculations.
- Use ALIGN() & define maar_align to make it clearer what's going on
with address manipulations.
- Drop the new used field from struct maar_config.
- Rework the RAM walk to avoid iterating over the cfg array needlessly
to find the first unused entry, then count used entries at the end.
Instead just keep the count as we go.]
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: yasha.che3@gmail.com
Cc: aurelien@aurel32.net
Cc: sfr@canb.auug.org.au
Cc: fancer.lancer@gmail.com
Cc: matt.redfearn@mips.com
Cc: chenhc@lemote.com
Pull more fallthrough fixes from Gustavo A. R. Silva:
"Fix fall-through warnings on arm and mips for multiple configurations"
* tag 'Wimplicit-fallthrough-5.3-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gustavoars/linux:
video: fbdev: acornfb: Mark expected switch fall-through
scsi: libsas: sas_discover: Mark expected switch fall-through
MIPS: Octeon: Mark expected switch fall-through
power: supply: ab8500_charger: Mark expected switch fall-through
watchdog: wdt285: Mark expected switch fall-through
mtd: sa1100: Mark expected switch fall-through
drm/sun4i: tcon: Mark expected switch fall-through
drm/sun4i: sun6i_mipi_dsi: Mark expected switch fall-through
ARM: riscpc: Mark expected switch fall-through
dmaengine: fsldma: Mark expected switch fall-through
Add CONFIG_ASM_MODVERSIONS. This allows to remove one if-conditional
nesting in scripts/Makefile.build.
scripts/Makefile.build is run every time Kbuild descends into a
sub-directory. So, I want to avoid $(wildcard ...) evaluation
where possible although computing $(wildcard ...) is so cheap that
it may not make measurable performance difference.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Mark switch cases where we are expecting to fall through.
Fix the following warning (Building: cavium_octeon_defconfig mips):
arch/mips/include/asm/octeon/cvmx-sli-defs.h:47:6: warning: this statement
may fall through [-Wimplicit-fallthrough=]
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
clang warns:
arch/mips/mm/tlbex.c:634:19: error: use of logical '&&' with constant
operand [-Werror,-Wconstant-logical-operand]
if (cpu_has_rixi && _PAGE_NO_EXEC) {
^ ~~~~~~~~~~~~~
arch/mips/mm/tlbex.c:634:19: note: use '&' for a bitwise operation
if (cpu_has_rixi && _PAGE_NO_EXEC) {
^~
&
arch/mips/mm/tlbex.c:634:19: note: remove constant to silence this
warning
if (cpu_has_rixi && _PAGE_NO_EXEC) {
~^~~~~~~~~~~~~~~~
1 error generated.
Explicitly cast this value to a boolean so that clang understands we
intend for this to be a non-zero value.
Fixes: 00bf1c691d ("MIPS: tlbex: Avoid placing software PTE bits in Entry* PFN fields")
Link: https://github.com/ClangBuiltLinux/linux/issues/609
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: clang-built-linux@googlegroups.com
clang warns:
arch/mips/include/asm/syscall.h:136:3: error: variable 'ret' is
uninitialized when used here [-Werror,-Wuninitialized]
ret |= mips_get_syscall_arg(args++, task, regs, i++);
^~~
arch/mips/include/asm/syscall.h:129:9: note: initialize the variable
'ret' to silence this warning
int ret;
^
= 0
1 error generated.
It's not wrong; however, it's not an issue in practice because ret is
only assigned to, not read from. ret could just be initialized to zero
but looking into it further, ret has been unused since it was first
added in 2012 so just get rid of it and update mips_get_syscall_arg's
return type since none of the return values are ever checked. If it is
ever needed again, this commit can be reverted and ret can be properly
initialized.
Fixes: c0ff3c53d4 ("MIPS: Enable HAVE_ARCH_TRACEHOOK.")
Link: https://github.com/ClangBuiltLinux/linux/issues/604
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: clang-built-linux@googlegroups.com
Pull kvm fixes from Paolo Bonzini:
"Bugfixes (arm and x86) and cleanups"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
selftests: kvm: Adding config fragments
KVM: selftests: Update gitignore file for latest changes
kvm: remove unnecessary PageReserved check
KVM: arm/arm64: vgic: Reevaluate level sensitive interrupts on enable
KVM: arm: Don't write junk to CP15 registers on reset
KVM: arm64: Don't write junk to sysregs on reset
KVM: arm/arm64: Sync ICH_VMCR_EL2 back when about to block
x86: kvm: remove useless calls to kvm_para_available
KVM: no need to check return value of debugfs_create functions
KVM: remove kvm_arch_has_vcpu_debugfs()
KVM: Fix leak vCPU's VMCS value into other pCPU
KVM: Check preempted_in_kernel for involuntary preemption
KVM: LAPIC: Don't need to wakeup vCPU twice afer timer fire
arm64: KVM: hyp: debug-sr: Mark expected switch fall-through
KVM: arm64: Update kvm_arm_exception_class and esr_class_str for new EC
KVM: arm: vgic-v3: Mark expected switch fall-through
arm64: KVM: regmap: Fix unexpected switch fall-through
KVM: arm/arm64: Introduce kvm_pmu_vcpu_init() to setup PMU counter index
KVM/arm fixes for 5.3
- A bunch of switch/case fall-through annotation, fixing one actual bug
- Fix PMU reset bug
- Add missing exception class debug strings
Merge the Ingenic TCU patchset from the ingenic-tcu-v5.4 branch which
was created to enable follow-on changes in other subsystems.
Signed-off-by: Paul Burton <paul.burton@mips.com>
The cpu_has_saa feature macro was added along with Cavium Octeon CPU
support back in commit 5b3b16880f ("MIPS: Add Cavium OCTEON processor
support files to arch/mips/cavium-octeon.") but has never been used.
Remove the dead code.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Pull MIPS fixes from Paul Burton:
"A few MIPS fixes for 5.3:
- Various switch fall through annotations to fixup warnings & errors
resulting from -Wimplicit-fallthrough.
- A fix for systems (at least jazz) using an i8253 PIT as clocksource
when it's not suitably configured.
- Set struct cacheinfo's cpu_map_populated field to true, indicating
that we filled in cache info detected from cop0 registers &
avoiding complaints about that info being (intentionally) missing
in devicetree"
* tag 'mips_fixes_5.3_1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
MIPS: BCM63XX: Mark expected switch fall-through
MIPS: OProfile: Mark expected switch fall-throughs
MIPS: Annotate fall-through in Cavium Octeon code
MIPS: Annotate fall-through in kvm/emulate.c
mips: fix cacheinfo
MIPS: kernel: only use i8253 clocksource with periodic clockevent
There is no need for this function as all arches have to implement
kvm_arch_create_vcpu_debugfs() no matter what. A #define symbol
let us actually simplify the code.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
