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Author SHA1 Message Date
Linus Torvalds
1bc276775d Merge tag 'kbuild-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 
Pull more Kbuild updates from Masahiro Yamada:

 - add build_{menu,n,g,x}config targets for compile-testing Kconfig

 - fix and improve recursive dependency detection in Kconfig

 - fix parallel building of menuconfig/nconfig

 - fix syntax error in clang-version.sh

 - suppress distracting log from syncconfig

 - remove obsolete "rpm" target

 - remove VMLINUX_SYMBOL(_STR) macro entirely

 - fix microblaze build with CONFIG_DYNAMIC_FTRACE

 - move compiler test for dead code/data elimination to Kconfig

 - rename well-known LDFLAGS variable to KBUILD_LDFLAGS

 - misc fixes and cleanups

* tag 'kbuild-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: rename LDFLAGS to KBUILD_LDFLAGS
  kbuild: pass LDFLAGS to recordmcount.pl
  kbuild: test dead code/data elimination support in Kconfig
  initramfs: move gen_initramfs_list.sh from scripts/ to usr/
  vmlinux.lds.h: remove stale <linux/export.h> include
  export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR()
  Coccinelle: remove pci_alloc_consistent semantic to detect in zalloc-simple.cocci
  kbuild: make sorting initramfs contents independent of locale
  kbuild: remove "rpm" target, which is alias of "rpm-pkg"
  kbuild: Fix LOADLIBES rename in Documentation/kbuild/makefiles.txt
  kconfig: suppress "configuration written to .config" for syncconfig
  kconfig: fix "Can't open ..." in parallel build
  kbuild: Add a space after `!` to prevent parsing as file pattern
  scripts: modpost: check memory allocation results
  kconfig: improve the recursive dependency report
  kconfig: report recursive dependency involving 'imply'
  kconfig: error out when seeing recursive dependency
  kconfig: add build-only configurator targets
  scripts/dtc: consolidate include path options in Makefile
 2018-08-25 13:40:38 -07:00
Masahiro Yamada
d503ac531a kbuild: rename LDFLAGS to KBUILD_LDFLAGS 
Commit a0f97e06a4 ("kbuild: enable 'make CFLAGS=...' to add
additional options to CC") renamed CFLAGS to KBUILD_CFLAGS.

Commit 222d394d30 ("kbuild: enable 'make AFLAGS=...' to add
additional options to AS") renamed AFLAGS to KBUILD_AFLAGS.

Commit 06c5040cdb ("kbuild: enable 'make CPPFLAGS=...' to add
additional options to CPP") renamed CPPFLAGS to KBUILD_CPPFLAGS.

For some reason, LDFLAGS was not renamed.

Using a well-known variable like LDFLAGS may result in accidental
override of the variable.

Kbuild generally uses KBUILD_ prefixed variables for the internally
appended options, so here is one more conversion to sanitize the
naming convention.

I did not touch Makefiles under tools/ since the tools build system
is a different world.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
 2018-08-24 08:22:08 +09:00
Linus Torvalds
0c4b0f815f Merge tag 'mips_4.19_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux 
Pull MIPS fixes from Paul Burton:

  - Fix microMIPS build failures by adding a .insn directive to the
    barrier_before_unreachable() asm statement in order to convince the
    toolchain that the asm statement is a valid branch target rather
    than a bogus attempt to switch ISA.

  - Clean up our declarations of TLB functions that we overwrite with
    generated code in order to prevent the compiler making assumptions
    about alignment that cause microMIPS kernels built with GCC 7 &
    above to die early during boot.

  - Fix up a regression for MIPS32 kernels which slipped into the main
    MIPS pull for 4.19, causing CONFIG_32BIT=y kernels to contain
    inappropriate MIPS64 instructions.

  - Extend our existing workaround for MIPSr6 builds that end up using
    the __multi3 intrinsic to GCC 7 & below, rather than just GCC 7.

* tag 'mips_4.19_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: lib: Provide MIPS64r6 __multi3() for GCC < 7
  MIPS: Workaround GCC __builtin_unreachable reordering bug
  compiler.h: Allow arch-specific asm/compiler.h
  MIPS: Avoid move psuedo-instruction whilst using MIPS_ISA_LEVEL
  MIPS: Consistently declare TLB functions
  MIPS: Export tlbmiss_handler_setup_pgd near its definition
 2018-08-23 14:23:08 -07:00
Paul Burton
690d9163bf MIPS: lib: Provide MIPS64r6 __multi3() for GCC < 7 
Some versions of GCC suboptimally generate calls to the __multi3()
intrinsic for MIPS64r6 builds, resulting in link failures due to the
missing function:

    LD      vmlinux.o
    MODPOST vmlinux.o
  kernel/bpf/verifier.o: In function `kmalloc_array':
  include/linux/slab.h:631: undefined reference to `__multi3'
  fs/select.o: In function `kmalloc_array':
  include/linux/slab.h:631: undefined reference to `__multi3'
  ...

We already have a workaround for this in which we provide the
instrinsic, but we do so selectively for GCC 7 only. Unfortunately the
issue occurs with older GCC versions too - it has been observed with
both GCC 5.4.0 & GCC 6.4.0.

MIPSr6 support was introduced in GCC 5, so all major GCC versions prior
to GCC 8 are affected and we extend our workaround accordingly to all
MIPS64r6 builds using GCC versions older than GCC 8.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Reported-by: Vladimir Kondratiev <vladimir.kondratiev@intel.com>
Fixes: ebabcf17bc ("MIPS: Implement __multi3 for GCC7 MIPS64r6 builds")
Patchwork: https://patchwork.linux-mips.org/patch/20297/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # 4.15+
 2018-08-21 12:14:11 -07:00
Paul Burton
906d441feb MIPS: Workaround GCC __builtin_unreachable reordering bug 
Some versions of GCC for the MIPS architecture suffer from a bug which
can lead to instructions from beyond an unreachable statement being
incorrectly reordered into earlier branch delay slots if the unreachable
statement is the only content of a case in a switch statement. This can
lead to seemingly random behaviour, such as invalid memory accesses from
incorrectly reordered loads or stores, and link failures on microMIPS
builds.

See this potential GCC fix for details:

    https://gcc.gnu.org/ml/gcc-patches/2015-09/msg00360.html

Runtime problems resulting from this bug were initially observed using a
maltasmvp_defconfig v4.4 kernel built using GCC 4.9.2 (from a Codescape
SDK 2015.06-05 toolchain), with the result being an address exception
taken after log messages about the L1 caches (during probe of the L2
cache):

    Initmem setup node 0 [mem 0x0000000080000000-0x000000009fffffff]
    VPE topology {2,2} total 4
    Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
    Primary data cache 64kB, 4-way, PIPT, no aliases, linesize 32 bytes
    <AdEL exception here>

This is early enough that the kernel exception vectors are not in use,
so any further output depends upon the bootloader. This is reproducible
in QEMU where no further output occurs - ie. the system hangs here.
Given the nature of the bug it may potentially be hit with differing
symptoms. The bug is known to affect GCC versions as recent as 7.3, and
it is unclear whether GCC 8 fixed it or just happens not to encounter
the bug in the testcase found at the link above due to differing
optimizations.

This bug can be worked around by placing a volatile asm statement, which
GCC is prevented from reordering past, prior to the
__builtin_unreachable call.

That was actually done already for other reasons by commit 173a3efd3e
("bug.h: work around GCC PR82365 in BUG()"), but creates problems for
microMIPS builds due to the lack of a .insn directive. The microMIPS ISA
allows for interlinking with regular MIPS32 code by repurposing bit 0 of
the program counter as an ISA mode bit. To switch modes one changes the
value of this bit in the PC. However typical branch instructions encode
their offsets as multiples of 2-byte instruction halfwords, which means
they cannot change ISA mode - this must be done using either an indirect
branch (a jump-register in MIPS terminology) or a dedicated jalx
instruction. In order to ensure that regular branches don't attempt to
target code in a different ISA which they can't actually switch to, the
linker will check that branch targets are code in the same ISA as the
branch.

Unfortunately our empty asm volatile statements don't qualify as code,
and the link for microMIPS builds fails with errors such as:

    arch/mips/mm/dma-default.s:3265: Error: branch to a symbol in another ISA mode
    arch/mips/mm/dma-default.s:5027: Error: branch to a symbol in another ISA mode

Resolve this by adding a .insn directive within the asm statement which
declares that what comes next is code. This may or may not be true,
since we don't really know what comes next, but as this code is in an
unreachable path anyway that doesn't matter since we won't execute it.

We do this in asm/compiler.h & select CONFIG_HAVE_ARCH_COMPILER_H in
order to have this included by linux/compiler_types.h after
linux/compiler-gcc.h. This will result in asm/compiler.h being included
in all C compilations via the -include linux/compiler_types.h argument
in c_flags, which should be harmless.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: 173a3efd3e ("bug.h: work around GCC PR82365 in BUG()")
Patchwork: https://patchwork.linux-mips.org/patch/20270/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-mips@linux-mips.org
 2018-08-21 10:08:16 -07:00
Linus Torvalds
7140ad3898 Merge tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 
Pull tracing updates from Steven Rostedt:

 - Restructure of lockdep and latency tracers

   This is the biggest change. Joel Fernandes restructured the hooks
   from irqs and preemption disabling and enabling. He got rid of a lot
   of the preprocessor #ifdef mess that they caused.

   He turned both lockdep and the latency tracers to use trace events
   inserted in the preempt/irqs disabling paths. But unfortunately,
   these started to cause issues in corner cases. Thus, parts of the
   code was reverted back to where lockdep and the latency tracers just
   get called directly (without using the trace events). But because the
   original change cleaned up the code very nicely we kept that, as well
   as the trace events for preempt and irqs disabling, but they are
   limited to not being called in NMIs.

 - Have trace events use SRCU for "rcu idle" calls. This was required
   for the preempt/irqs off trace events. But it also had to not allow
   them to be called in NMI context. Waiting till Paul makes an NMI safe
   SRCU API.

 - New notrace SRCU API to allow trace events to use SRCU.

 - Addition of mcount-nop option support

 - SPDX headers replacing GPL templates.

 - Various other fixes and clean ups.

 - Some fixes are marked for stable, but were not fully tested before
   the merge window opened.

* tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits)
  tracing: Fix SPDX format headers to use C++ style comments
  tracing: Add SPDX License format tags to tracing files
  tracing: Add SPDX License format to bpf_trace.c
  blktrace: Add SPDX License format header
  s390/ftrace: Add -mfentry and -mnop-mcount support
  tracing: Add -mcount-nop option support
  tracing: Avoid calling cc-option -mrecord-mcount for every Makefile
  tracing: Handle CC_FLAGS_FTRACE more accurately
  Uprobe: Additional argument arch_uprobe to uprobe_write_opcode()
  Uprobes: Simplify uprobe_register() body
  tracepoints: Free early tracepoints after RCU is initialized
  uprobes: Use synchronize_rcu() not synchronize_sched()
  tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister()
  ftrace: Remove unused pointer ftrace_swapper_pid
  tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage"
  tracing/irqsoff: Handle preempt_count for different configs
  tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage"
  tracing: irqsoff: Account for additional preempt_disable
  trace: Use rcu_dereference_raw for hooks from trace-event subsystem
  tracing/kprobes: Fix within_notrace_func() to check only notrace functions
  ...
 2018-08-20 18:32:00 -07:00
Paul Burton
cfd54de3b0 MIPS: Avoid move psuedo-instruction whilst using MIPS_ISA_LEVEL 
MIPS_ISA_LEVEL is always defined as the 64 bit ISA that is a compatible
superset of the ISA that the kernel build is targeting, and is used to
allow us to emit instructions that we may detect support for at runtime.

When we use a .set MIPS_ISA_LEVEL directive & are building a 32-bit
kernel, we therefore are temporarily allowing the assembler to generate
MIPS64 instructions. Using the move pseudo-instruction whilst this is
the case is problematic because the assembler is likely to emit a daddu
instruction which will generate a reserved instruction exception when
executed on a MIPS32 machine.

Unfortunately the combination of commit a0a5ac3ce8 ("MIPS: Fix delay
slot bug in `atomic*_sub_if_positive' for R10000_LLSC_WAR") and commit
4936084c2e ("MIPS: Cleanup R10000_LLSC_WAR logic in atomic.h") causes
us to do exactly this in atomic_sub_if_positive(), and the result is
MIPS64 daddu instructions in 32-bit kernels.

Fix this by using .set mips0 to restore the default ISA after the ll
instruction, and use .set MIPS_ISA_LEVEL again prior to the sc. This
ensures everything but the ll & sc are assembled using the default ISA
for the kernel build & the move pseudo-instruction is emitted as a
MIPS32 addu instruction.

We appear to have another pre-existing instance of the same issue in our
atomic_fetch_*_relaxed() functions, and fix that up too by moving our
.set move0 such that it occurs prior to use of the move
pseudo-instruction.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Fixes: a0a5ac3ce8 ("MIPS: Fix delay slot bug in `atomic*_sub_if_positive' for R10000_LLSC_WAR")
Fixes: 4936084c2e ("MIPS: Cleanup R10000_LLSC_WAR logic in atomic.h")
Patchwork: https://patchwork.linux-mips.org/patch/20253/
Cc: James Hogan <jhogan@kernel.org>
Cc: Joshua Kinard <kumba@gentoo.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
 2018-08-17 16:40:11 -07:00
Souptick Joarder
50a7ca3c6f mm: convert return type of handle_mm_fault() caller to vm_fault_t 
Use new return type vm_fault_t for fault handler.  For now, this is just
documenting that the function returns a VM_FAULT value rather than an
errno.  Once all instances are converted, vm_fault_t will become a
distinct type.

Ref-> commit 1c8f422059 ("mm: change return type to vm_fault_t")

In this patch all the caller of handle_mm_fault() are changed to return
vm_fault_t type.

Link: http://lkml.kernel.org/r/20180617084810.GA6730@jordon-HP-15-Notebook-PC
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: James Hogan <jhogan@kernel.org>
Cc: Ley Foon Tan <lftan@altera.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: David S. Miller <davem@davemloft.net>
Cc: Richard Weinberger <richard@nod.at>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 2018-08-17 16:20:28 -07:00
Linus Torvalds
dafa5f6577 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 
Pull crypto updates from Herbert Xu:
 "API:
   - Fix dcache flushing crash in skcipher.
   - Add hash finup self-tests.
   - Reschedule during speed tests.

  Algorithms:
   - Remove insecure vmac and replace it with vmac64.
   - Add public key verification for DH/ECDH.

  Drivers:
   - Decrease priority of sha-mb on x86.
   - Improve NEON latency/throughput on ARM64.
   - Add md5/sha384/sha512/des/3des to inside-secure.
   - Support eip197d in inside-secure.
   - Only register algorithms supported by the host in virtio.
   - Add cts and remove incompatible cts1 from ccree.
   - Add hisilicon SEC security accelerator driver.
   - Replace msm hwrng driver with qcom pseudo rng driver.

  Misc:
   - Centralize CRC polynomials"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (121 commits)
  crypto: arm64/ghash-ce - implement 4-way aggregation
  crypto: arm64/ghash-ce - replace NEON yield check with block limit
  crypto: hisilicon - sec_send_request() can be static
  lib/mpi: remove redundant variable esign
  crypto: arm64/aes-ce-gcm - don't reload key schedule if avoidable
  crypto: arm64/aes-ce-gcm - implement 2-way aggregation
  crypto: arm64/aes-ce-gcm - operate on two input blocks at a time
  crypto: dh - make crypto_dh_encode_key() make robust
  crypto: dh - fix calculating encoded key size
  crypto: ccp - Check for NULL PSP pointer at module unload
  crypto: arm/chacha20 - always use vrev for 16-bit rotates
  crypto: ccree - allow bigger than sector XTS op
  crypto: ccree - zero all of request ctx before use
  crypto: ccree - remove cipher ivgen left overs
  crypto: ccree - drop useless type flag during reg
  crypto: ablkcipher - fix crash flushing dcache in error path
  crypto: blkcipher - fix crash flushing dcache in error path
  crypto: skcipher - fix crash flushing dcache in error path
  crypto: skcipher - remove unnecessary setting of walk->nbytes
  crypto: scatterwalk - remove scatterwalk_samebuf()
  ...
 2018-08-15 16:01:47 -07:00
Linus Torvalds
9a76aba02a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 
Pull networking updates from David Miller:
 "Highlights:

   - Gustavo A. R. Silva keeps working on the implicit switch fallthru
     changes.

   - Support 802.11ax High-Efficiency wireless in cfg80211 et al, From
     Luca Coelho.

   - Re-enable ASPM in r8169, from Kai-Heng Feng.

   - Add virtual XFRM interfaces, which avoids all of the limitations of
     existing IPSEC tunnels. From Steffen Klassert.

   - Convert GRO over to use a hash table, so that when we have many
     flows active we don't traverse a long list during accumluation.

   - Many new self tests for routing, TC, tunnels, etc. Too many
     contributors to mention them all, but I'm really happy to keep
     seeing this stuff.

   - Hardware timestamping support for dpaa_eth/fsl-fman from Yangbo Lu.

   - Lots of cleanups and fixes in L2TP code from Guillaume Nault.

   - Add IPSEC offload support to netdevsim, from Shannon Nelson.

   - Add support for slotting with non-uniform distribution to netem
     packet scheduler, from Yousuk Seung.

   - Add UDP GSO support to mlx5e, from Boris Pismenny.

   - Support offloading of Team LAG in NFP, from John Hurley.

   - Allow to configure TX queue selection based upon RX queue, from
     Amritha Nambiar.

   - Support ethtool ring size configuration in aquantia, from Anton
     Mikaev.

   - Support DSCP and flowlabel per-transport in SCTP, from Xin Long.

   - Support list based batching and stack traversal of SKBs, this is
     very exciting work. From Edward Cree.

   - Busyloop optimizations in vhost_net, from Toshiaki Makita.

   - Introduce the ETF qdisc, which allows time based transmissions. IGB
     can offload this in hardware. From Vinicius Costa Gomes.

   - Add parameter support to devlink, from Moshe Shemesh.

   - Several multiplication and division optimizations for BPF JIT in
     nfp driver, from Jiong Wang.

   - Lots of prepatory work to make more of the packet scheduler layer
     lockless, when possible, from Vlad Buslov.

   - Add ACK filter and NAT awareness to sch_cake packet scheduler, from
     Toke Høiland-Jørgensen.

   - Support regions and region snapshots in devlink, from Alex Vesker.

   - Allow to attach XDP programs to both HW and SW at the same time on
     a given device, with initial support in nfp. From Jakub Kicinski.

   - Add TLS RX offload and support in mlx5, from Ilya Lesokhin.

   - Use PHYLIB in r8169 driver, from Heiner Kallweit.

   - All sorts of changes to support Spectrum 2 in mlxsw driver, from
     Ido Schimmel.

   - PTP support in mv88e6xxx DSA driver, from Andrew Lunn.

   - Make TCP_USER_TIMEOUT socket option more accurate, from Jon
     Maxwell.

   - Support for templates in packet scheduler classifier, from Jiri
     Pirko.

   - IPV6 support in RDS, from Ka-Cheong Poon.

   - Native tproxy support in nf_tables, from Máté Eckl.

   - Maintain IP fragment queue in an rbtree, but optimize properly for
     in-order frags. From Peter Oskolkov.

   - Improvde handling of ACKs on hole repairs, from Yuchung Cheng"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1996 commits)
  bpf: test: fix spelling mistake "REUSEEPORT" -> "REUSEPORT"
  hv/netvsc: Fix NULL dereference at single queue mode fallback
  net: filter: mark expected switch fall-through
  xen-netfront: fix warn message as irq device name has '/'
  cxgb4: Add new T5 PCI device ids 0x50af and 0x50b0
  net: dsa: mv88e6xxx: missing unlock on error path
  rds: fix building with IPV6=m
  inet/connection_sock: prefer _THIS_IP_ to current_text_addr
  net: dsa: mv88e6xxx: bitwise vs logical bug
  net: sock_diag: Fix spectre v1 gadget in __sock_diag_cmd()
  ieee802154: hwsim: using right kind of iteration
  net: hns3: Add vlan filter setting by ethtool command -K
  net: hns3: Set tx ring' tc info when netdev is up
  net: hns3: Remove tx ring BD len register in hns3_enet
  net: hns3: Fix desc num set to default when setting channel
  net: hns3: Fix for phy link issue when using marvell phy driver
  net: hns3: Fix for information of phydev lost problem when down/up
  net: hns3: Fix for command format parsing error in hclge_is_all_function_id_zero
  net: hns3: Add support for serdes loopback selftest
  bnxt_en: take coredump_record structure off stack
  ...
 2018-08-15 15:04:25 -07:00
Linus Torvalds
fa1b5d09d0 Merge tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild 
Pull Kconfig consolidation from Masahiro Yamada:
 "Consolidation of Kconfig files by Christoph Hellwig.

  Move the source statements of arch-independent Kconfig files instead
  of duplicating the includes in every arch/$(SRCARCH)/Kconfig"

* tag 'kconfig-v4.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: add a Memory Management options" menu
  kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt
  kconfig: use a menu in arch/Kconfig to reduce clutter
  kconfig: include kernel/Kconfig.preempt from init/Kconfig
  Kconfig: consolidate the "Kernel hacking" menu
  kconfig: include common Kconfig files from top-level Kconfig
  kconfig: remove duplicate SWAP symbol defintions
  um: create a proper drivers Kconfig
  um: cleanup Kconfig files
  um: stop abusing KBUILD_KCONFIG
 2018-08-15 13:05:12 -07:00
Linus Torvalds
c2fc71c9b7 Merge tag 'mtd/for-4.19' of git://git.infradead.org/linux-mtd 
Pull mtd updates from Boris Brezillon:
 "JFFS2 changes:
   - Support 64-bit timestamps

  MTD core changes:
   - Support sub-partitions
   - Clarify mtd_oob_ops documentation
   - Make Kconfig formatting consistent
   - Fix potential overflows in mtdchar_{write,read}()
   - Fallback to ->_{read,write}() when ->_{read,write}_oob() is missing
     and no OOB data were requested
   - Remove VLA usage in the bch lib

  MTD driver changes:
   - Use mtd_device_register() instead of mtd_device_parse_register()
     where applicable
   - Use proper printk format to print physical addresses in the
     solutionengine driver
   - Add missing mtd_set_of_node() call in the powernv driver
   - Remove unneeded variables in a few drivers
   - Plug the TRX part parser to the DT partition parsers logic
   - Check ioremap_cache() return code in the gpio-addr-flash driver
   - Stop using VMLINUX_SYMBOL_STR() in gen_probe.c

  SPI NOR core changes:
   - Apply reset hacks only when reset is explicitly marked as broken in
     the DT

   SPI NOR driver changes:
   - Minor cleanup/fixes in the m25p80 driver
   - Release flash_np in the nxp-spifi driver
   - Add suspend/resume hooks to the atmel-quadspi driver
   - Include gpio/consumer.h instead of gpio.h in the atmel-quadspi
     driver
   - Use %pK instead of %p in the stm32-quadspi driver
   - Improve timeout handling in the cadence-quadspi driver
   - Use mtd_device_register() instead of mtd_device_parse_register() in
     the intel-spi driver

  NAND core changes:
   - Add the SPI-NAND framework.
   - Create a helper to find the best ECC configuration.
   - Create NAND controller operations.
   - Allocate dynamically ONFI parameters structure.
   - Add defines for ONFI version bits.
   - Add manufacturer fixup for ONFI parameter page.
   - Add an option to specify NAND chip as a boot device.
   - Add Reed-Solomon error correction algorithm.
   - Better name for the controller structure.
   - Remove unused caller_is_module() definition.
   - Make subop helpers return unsigned values.
   - Expose _notsupp() helpers for raw page accessors.
   - Add default values for dynamic timings.
   - Kill the chip->scan_bbt() hook.
   - Rename nand_default_bbt() into nand_create_bbt().
   - Start to clean the nand_chip structure.
   - Remove stale prototype from rawnand.h.

  Raw NAND controllers drivers changes:
   - Qcom: structuring cleanup.
   - Denali: use core helper to find the best ECC configuration.
   - Possible build of almost all drivers by adding a dependency on
     COMPILE_TEST for almost all of them in Kconfig, implies various
     fixes, Kconfig cleanup, GPIO headers inclusion cleanup, and even
     changes in sparc64 and ia64 architectures.
   - Clean the ->probe() functions error path of a lot of drivers.
   - Migrate all drivers to use nand_scan() instead of
     nand_scan_ident()/nand_scan_tail() pair.
   - Use mtd_device_register() where applicable to simplify the code.
   - Marvell:
      * Handle on-die ECC.
      * Better clocks handling.
      * Remove bogus comment.
      * Add suspend and resume support.
   - Tegra: add NAND controller driver.
   - Atmel:
      * Add module param to avoid using dma.
      * Drop Wenyou Yang from MAINTAINERS.
   - Denali: optimize timings handling.
   - FSMC: Stop using chip->read_buf().
   - FSL:
      * Switch to SPDX license tag identifiers.
      * Fix qualifiers in MXC init functions.

  Raw NAND chip drivers changes:
   - Micron:
      * Add fixup for ONFI revision.
      * Update ecc_stats.corrected.
      * Make ECC activation stateful.
      * Avoid enabling/disabling ECC when it can't be disabled.
      * Get the actual number of bitflips.
      * Allow forced on-die ECC.
      * Support 8/512 on-die ECC.
      * Fix on-die ECC detection logic.
   - Hynix:
      * Fix decoding the OOB size on H27UCG8T2BTR.
      * Use ->exec_op() in hynix_nand_reg_write_op()"

* tag 'mtd/for-4.19' of git://git.infradead.org/linux-mtd: (188 commits)
  mtd: rawnand: atmel: Select GENERIC_ALLOCATOR
  MAINTAINERS: drop Wenyou Yang from Atmel NAND driver support
  mtd: rawnand: allocate dynamically ONFI parameters during detection
  mtd: spi-nor: only apply reset hacks to broken hardware
  mtd: spi-nor: cadence-quadspi: fix timeout handling
  mtd: spi-nor: atmel-quadspi: Include gpio/consumer.h instead of gpio.h
  mtd: spi-nor: intel-spi: use mtd_device_register()
  mtd: spi-nor: stm32-quadspi: replace "%p" with "%pK"
  mtd: spi-nor: atmel-quadspi: add suspend/resume hooks
  mtd: rawnand: allocate model parameter dynamically
  mtd: rawnand: do not export nand_scan_[ident|tail]() anymore
  mtd: rawnand: txx9ndfmc: convert driver to nand_scan()
  mtd: rawnand: txx9ndfmc: clarify ECC parameters assignation
  mtd: rawnand: tegra: convert driver to nand_scan()
  mtd: rawnand: jz4740: convert driver to nand_scan()
  mtd: rawnand: jz4740: group nand_scan_{ident, tail} calls
  mtd: rawnand: jz4740: fix probe function error path
  mtd: rawnand: docg4: convert driver to nand_scan()
  mtd: rawnand: do not execute nand_scan_ident() if maxchips is zero
  mtd: rawnand: atmel: convert driver to nand_scan()
  ...
 2018-08-14 10:57:44 -07:00
Linus Torvalds
e5a32b5b21 Merge tag 'mips_4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux 
Pull MIPS updates from Paul Burton:
 "Here are the main MIPS changes for 4.19.

  An overview of the general architecture changes:

   - Massive DMA ops refactoring from Christoph Hellwig (huzzah for
     deleting crufty code!).

   - We introduce NT_MIPS_DSP & NT_MIPS_FP_MODE ELF notes &
     corresponding regsets to expose DSP ASE & floating point mode state
     respectively, both for live debugging & core dumps.

   - We better optimize our code by hard-coding cpu_has_* macros at
     compile time where their values are known due to the ISA revision
     that the kernel build is targeting.

   - The EJTAG exception handler now better handles SMP systems, where
     it was previously possible for CPUs to clobber a register value
     saved by another CPU.

   - Our implementation of memset() gained a couple of fixes for MIPSr6
     systems to return correct values in some cases where stores fault.

   - We now implement ioremap_wc() using the uncached-accelerated cache
     coherency attribute where supported, which is detected during boot,
     and fall back to plain uncached access where necessary. The
     MIPS-specific (and unused in tree) ioremap_uncached_accelerated() &
     ioremap_cacheable_cow() are removed.

   - The prctl(PR_SET_FP_MODE, ...) syscall is better supported for SMP
     systems by reworking the way we ensure remote CPUs that may be
     running threads within the affected process switch mode.

   - Systems using the MIPS Coherence Manager will now set the
     MIPS_IC_SNOOPS_REMOTE flag to avoid some unnecessary cache
     maintenance overhead when flushing the icache.

   - A few fixes were made for building with clang/LLVM, which now
     sucessfully builds kernels for many of our platforms.

   - Miscellaneous cleanups all over.

  And some platform-specific changes:

   - ar7 gained stubs for a few clock API functions to fix build
     failures for some drivers.

   - ath79 gained support for a few new SoCs, a few fixes & better
     gpio-keys support.

   - Ci20 now exposes its SPI bus using the spi-gpio driver.

   - The generic platform can now auto-detect a suitable value for
     PHYS_OFFSET based upon the memory map described by the device tree,
     allowing us to avoid wasting memory on page book-keeping for
     systems where RAM starts at a non-zero physical address.

   - Ingenic systems using the jz4740 platform code now link their
     vmlinuz higher to allow for kernels of a realistic size.

   - Loongson32 now builds the kernel targeting MIPSr1 rather than
     MIPSr2 to avoid CPU errata.

   - Loongson64 gains a couple of fixes, a workaround for a write
     buffering issue & support for the Loongson 3A R3.1 CPU.

   - Malta now uses the piix4-poweroff driver to handle powering down.

   - Microsemi Ocelot gained support for its SPI bus & NOR flash, its
     second MDIO bus and can now be supported by a FIT/.itb image.

   - Octeon saw a bunch of header cleanups which remove a lot of
     duplicate or unused code"

* tag 'mips_4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (123 commits)
  MIPS: Remove remnants of UASM_ISA
  MIPS: netlogic: xlr: Remove erroneous check in nlm_fmn_send()
  MIPS: VDSO: Force link endianness
  MIPS: Always specify -EB or -EL when using clang
  MIPS: Use dins to simplify __write_64bit_c0_split()
  MIPS: Use read-write output operand in __write_64bit_c0_split()
  MIPS: Avoid using array as parameter to write_c0_kpgd()
  MIPS: vdso: Allow clang's --target flag in VDSO cflags
  MIPS: genvdso: Remove GOT checks
  MIPS: Remove obsolete MIPS checks for DST node "chosen@0"
  MIPS: generic: Remove input symbols from defconfig
  MIPS: Delete unused code in linux32.c
  MIPS: Remove unused sys_32_mmap2
  MIPS: Remove nabi_no_regargs
  mips: dts: mscc: enable spi and NOR flash support on ocelot PCB123
  mips: dts: mscc: Add spi on Ocelot
  MIPS: Loongson: Merge load addresses
  MIPS: Loongson: Set Loongson32 to MIPS32R1
  MIPS: mscc: ocelot: add interrupt controller properties to GPIO controller
  MIPS: generic: Select MIPS_AUTO_PFN_OFFSET
  ...
 2018-08-13 19:24:32 -07:00
Ravi Bangoria
6d43743e90 Uprobe: Additional argument arch_uprobe to uprobe_write_opcode() 
Add addition argument 'arch_uprobe' to uprobe_write_opcode().
We need this in later set of patches.

Link: http://lkml.kernel.org/r/20180809041856.1547-3-ravi.bangoria@linux.ibm.com

Reviewed-by: Song Liu <songliubraving@fb.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
 2018-08-13 20:08:33 -04:00
Linus Torvalds
8603596a32 Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 
Pull perf update from Thomas Gleixner:
 "The perf crowd presents:

  Kernel updates:

   - Removal of jprobes

   - Cleanup and consolidatation the handling of kprobes

   - Cleanup and consolidation of hardware breakpoints

   - The usual pile of fixes and updates to PMUs and event descriptors

  Tooling updates:

   - Updates and improvements all over the place. Nothing outstanding,
     just the (good) boring incremental grump work"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (103 commits)
  perf trace: Do not require --no-syscalls to suppress strace like output
  perf bpf: Include uapi/linux/bpf.h from the 'perf trace' script's bpf.h
  perf tools: Allow overriding MAX_NR_CPUS at compile time
  perf bpf: Show better message when failing to load an object
  perf list: Unify metric group description format with PMU event description
  perf vendor events arm64: Update ThunderX2 implementation defined pmu core events
  perf cs-etm: Generate branch sample for CS_ETM_TRACE_ON packet
  perf cs-etm: Generate branch sample when receiving a CS_ETM_TRACE_ON packet
  perf cs-etm: Support dummy address value for CS_ETM_TRACE_ON packet
  perf cs-etm: Fix start tracing packet handling
  perf build: Fix installation directory for eBPF
  perf c2c report: Fix crash for empty browser
  perf tests: Fix indexing when invoking subtests
  perf trace: Beautify the AF_INET & AF_INET6 'socket' syscall 'protocol' args
  perf trace beauty: Add beautifiers for 'socket''s 'protocol' arg
  perf trace beauty: Do not print NULL strarray entries
  perf beauty: Add a generator for IPPROTO_ socket's protocol constants
  tools include uapi: Grab a copy of linux/in.h
  perf tests: Fix complex event name parsing
  perf evlist: Fix error out while applying initial delay and LBR
  ...
 2018-08-13 12:55:49 -07:00
Linus Torvalds
de5d1b39ea Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 
Pull locking/atomics update from Thomas Gleixner:
 "The locking, atomics and memory model brains delivered:

   - A larger update to the atomics code which reworks the ordering
     barriers, consolidates the atomic primitives, provides the new
     atomic64_fetch_add_unless() primitive and cleans up the include
     hell.

   - Simplify cmpxchg() instrumentation and add instrumentation for
     xchg() and cmpxchg_double().

   - Updates to the memory model and documentation"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
  locking/atomics: Rework ordering barriers
  locking/atomics: Instrument cmpxchg_double*()
  locking/atomics: Instrument xchg()
  locking/atomics: Simplify cmpxchg() instrumentation
  locking/atomics/x86: Reduce arch_cmpxchg64*() instrumentation
  tools/memory-model: Rename litmus tests to comply to norm7
  tools/memory-model/Documentation: Fix typo, smb->smp
  sched/Documentation: Update wake_up() & co. memory-barrier guarantees
  locking/spinlock, sched/core: Clarify requirements for smp_mb__after_spinlock()
  sched/core: Use smp_mb() in wake_woken_function()
  tools/memory-model: Add informal LKMM documentation to MAINTAINERS
  locking/atomics/Documentation: Describe atomic_set() as a write operation
  tools/memory-model: Make scripts executable
  tools/memory-model: Remove ACCESS_ONCE() from model
  tools/memory-model: Remove ACCESS_ONCE() from recipes
  locking/memory-barriers.txt/kokr: Update Korean translation to fix broken DMA vs. MMIO ordering example
  MAINTAINERS: Add Daniel Lustig as an LKMM reviewer
  tools/memory-model: Fix ISA2+pooncelock+pooncelock+pombonce name
  tools/memory-model: Add litmus test for full multicopy atomicity
  locking/refcount: Always allow checked forms
  ...
 2018-08-13 12:23:39 -07:00
Linus Torvalds
f7951c33f0 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 
Pull scheduler updates from Thomas Gleixner:

 - Cleanup and improvement of NUMA balancing

 - Refactoring and improvements to the PELT (Per Entity Load Tracking)
   code

 - Watchdog simplification and related cleanups

 - The usual pile of small incremental fixes and improvements

* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (41 commits)
  watchdog: Reduce message verbosity
  stop_machine: Reflow cpu_stop_queue_two_works()
  sched/numa: Move task_numa_placement() closer to numa_migrate_preferred()
  sched/numa: Use group_weights to identify if migration degrades locality
  sched/numa: Update the scan period without holding the numa_group lock
  sched/numa: Remove numa_has_capacity()
  sched/numa: Modify migrate_swap() to accept additional parameters
  sched/numa: Remove unused task_capacity from 'struct numa_stats'
  sched/numa: Skip nodes that are at 'hoplimit'
  sched/debug: Reverse the order of printing faults
  sched/numa: Use task faults only if numa_group is not yet set up
  sched/numa: Set preferred_node based on best_cpu
  sched/numa: Simplify load_too_imbalanced()
  sched/numa: Evaluate move once per node
  sched/numa: Remove redundant field
  sched/debug: Show the sum wait time of a task group
  sched/fair: Remove #ifdefs from scale_rt_capacity()
  sched/core: Remove get_cpu() from sched_fork()
  sched/cpufreq: Clarify sugov_get_util()
  sched/sysctl: Remove unused sched_time_avg_ms sysctl
  ...
 2018-08-13 11:25:07 -07:00
Paul Burton
4bcb4ad663 MIPS: Consistently declare TLB functions 
Since at least the beginning of the git era we've declared our TLB
exception handling functions inconsistently. They're actually functions,
but we declare them as arrays of u32 where each u32 is an encoded
instruction. This has always been the case for arch/mips/mm/tlbex.c, and
has also been true for arch/mips/kernel/traps.c since commit
86a1708a9d ("MIPS: Make tlb exception handler definitions and
declarations match.") which aimed for consistency but did so by
consistently making the our C code inconsistent with our assembly.

This is all usually harmless, but when using GCC 7 or newer to build a
kernel targeting microMIPS (ie. CONFIG_CPU_MICROMIPS=y) it becomes
problematic. With microMIPS bit 0 of the program counter indicates the
ISA mode. When bit 0 is zero instructions are decoded using the standard
MIPS32 or MIPS64 ISA. When bit 0 is one instructions are decoded using
microMIPS. This means that function pointers become odd - their least
significant bit is one for microMIPS code. We work around this in cases
where we need to access code using loads & stores with our
msk_isa16_mode() macro which simply clears bit 0 of the value it is
given:

  #define msk_isa16_mode(x) ((x) & ~0x1)

For example we do this for our TLB load handler in
build_r4000_tlb_load_handler():

  u32 *p = (u32 *)msk_isa16_mode((ulong)handle_tlbl);

We then write code to p, expecting it to be suitably aligned (our LEAF
macro aligns functions on 4 byte boundaries, so (ulong)handle_tlbl will
give a value one greater than a multiple of 4 - ie. the start of a
function on a 4 byte boundary, with the ISA mode bit 0 set).

This worked fine up to GCC 6, but GCC 7 & onwards is smart enough to
presume that handle_tlbl which we declared as an array of u32s must be
aligned sufficiently that bit 0 of its address will never be set, and as
a result optimize out msk_isa16_mode(). This leads to p having an
address with bit 0 set, and when we go on to attempt to store code at
that address we take an address error exception due to the unaligned
memory access.

This leads to an exception prior to the kernel having configured its own
exception handlers, so we jump to whatever handlers the bootloader
configured. In the case of QEMU this results in a silent hang, since it
has no useful general exception vector.

Fix this by consistently declaring our TLB-related functions as
functions. For handle_tlbl(), handle_tlbs() & handle_tlbm() we do this
in asm/tlbex.h & we make use of the existing declaration of
tlbmiss_handler_setup_pgd() in asm/mmu_context.h. Our TLB handler
generation code in arch/mips/mm/tlbex.c is adjusted to deal with these
definitions, in most cases simply by casting the function pointers to
u32 pointers.

This allows us to include asm/mmu_context.h in arch/mips/mm/tlbex.c to
get the definitions of tlbmiss_handler_setup_pgd & pgd_current, removing
some needless duplication. Consistently using msk_isa16_mode() on
function pointers means we no longer need the
tlbmiss_handler_setup_pgd_start symbol so that is removed entirely.

Now that we're declaring our functions as functions GCC stops optimizing
out msk_isa16_mode() & a microMIPS kernel built with either GCC 7.3.0 or
8.1.0 boots successfully.

Signed-off-by: Paul Burton <paul.burton@mips.com>
 2018-08-10 17:27:53 -07:00
Paul Burton
b29fea3676 MIPS: Export tlbmiss_handler_setup_pgd near its definition 
We export tlbmiss_handler_setup_pgd in arch/mips/mm/tlbex.c close to a
declaration of it, rather than close to its definition as is standard.

We've supported exporting symbols in assembly code since commit
22823ab419 ("EXPORT_SYMBOL() for asm"), so move the export to follow
the function's (stub) definition.

Signed-off-by: Paul Burton <paul.burton@mips.com>
 2018-08-10 17:27:51 -07:00
Paul Burton
22f20a1103 MIPS: Remove remnants of UASM_ISA 
Commit 33679a5037 ("MIPS: uasm: Remove needless ISA abstraction")
removed use of the MIPS_ISA preprocessor macro, but left a couple of
unused definitions of it behind.

Remove the dead code.

Signed-off-by: Paul Burton <paul.burton@mips.com>
 2018-08-09 14:45:00 -07:00
Michael Büsch
209b43759d ssb: Remove SSB_WARN_ON, SSB_BUG_ON and SSB_DEBUG 
Use the standard WARN_ON instead.
If a small kernel is desired, WARN_ON can be disabled globally.

Also remove SSB_DEBUG. Besides WARN_ON it only adds a tiny debug check.
Include this check unconditionally.

Signed-off-by: Michael Buesch <m@bues.ch>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
 2018-08-09 18:47:47 +03:00
Paul Burton
02eec6c9fc MIPS: netlogic: xlr: Remove erroneous check in nlm_fmn_send() 
In nlm_fmn_send() we have a loop which attempts to send a message
multiple times in order to handle the transient failure condition of a
lack of available credit. When examining the status register to detect
the failure we check for a condition that can never be true, which falls
foul of gcc 8's -Wtautological-compare:

  In file included from arch/mips/netlogic/common/irq.c:65:
  ./arch/mips/include/asm/netlogic/xlr/fmn.h: In function 'nlm_fmn_send':
  ./arch/mips/include/asm/netlogic/xlr/fmn.h:304:22: error: bitwise
    comparison always evaluates to false [-Werror=tautological-compare]
     if ((status & 0x2) == 1)
                        ^~

If the path taken if this condition were true all we do is print a
message to the kernel console. Since failures seem somewhat expected
here (making the console message questionable anyway) and the condition
has clearly never evaluated true we simply remove it, rather than
attempting to fix it to check status correctly.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20174/
Cc: Ganesan Ramalingam <ganesanr@broadcom.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Jayachandran C <jnair@caviumnetworks.com>
Cc: John Crispin <john@phrozen.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
 2018-08-08 09:48:32 -07:00
Paul Burton
2f0025675f MIPS: VDSO: Force link endianness 
When building the VDSO with clang it appears to invoke ld without
specifying endianness, even though clang itself was provided with a -EB
or -EL flag. This results in the build failing due to a mismatch between
the objects that are the input to ld, and the output it is attempting to
create:

  VDSO    arch/mips/vdso/vdso.so.dbg.raw
  mips-linux-ld: arch/mips/vdso/elf.o: compiled for a big endian system
    and target is little endian
  mips-linux-ld: arch/mips/vdso/elf.o: endianness incompatible with that
    of the selected emulation
  mips-linux-ld: failed to merge target specific data of file
    arch/mips/vdso/elf.o
  ...

Work around this problem by explicitly specifying the link endianness
using -Wl,-EB or -Wl,-EL when -EB or -EL are part of KBUILD_CFLAGS. This
resolves the build failure when using clang, and doesn't have any
negative effect on gcc.

Signed-off-by: Paul Burton <paul.burton@mips.com>
 2018-08-07 16:16:13 -07:00
Paul Burton
c6d6f4c55f MIPS: Always specify -EB or -EL when using clang 
When building using clang, always specify -EB or -EL in order to ensure
we target the desired endianness.

Since clang cross compiles using a single compiler build with multiple
targets, our -dumpmachine tests which don't specify clang's --target
argument check output based upon the build machine rather than the
machine our build will target. This means our detection of whether to
specify -EB fails miserably & we never do. Providing the endianness flag
unconditionally for clang resolves this issue & simplifies the clang
path somewhat.

Signed-off-by: Paul Burton <paul.burton@mips.com>
 2018-08-07 16:16:08 -07:00
Paul Burton
36dc5b20e3 MIPS: Use dins to simplify __write_64bit_c0_split() 
The code in __write_64bit_c0_split() is used by MIPS32 kernels running
on MIPS64 CPUs to write a 64-bit value to a 64-bit coprocessor 0
register using a single 64-bit dmtc0 instruction. It does this by
combining the 2x 32-bit registers used to hold the 64-bit value into a
single register, which in the existing code involves three steps:

  1) Zero extend register A which holds bits 31:0 of our data, since it
     may have previously held a sign-extended value.

  2) Shift register B which holds bits 63:32 of our data in bits 31:0
     left by 32 bits, such that the bits forming our data are in the
     position they'll be in the final 64-bit value & bits 31:0 of the
     register are zero.

  3) Or the two registers together to form the 64-bit value in one
     64-bit register.

From MIPS r2 onwards we have a dins instruction which can effectively
perform all 3 of those steps using a single instruction.

Add a path for MIPS r2 & beyond which uses dins to take bits 31:0 from
register B & insert them into bits 63:32 of register A, giving us our
full 64-bit value in register A with one instruction.

Since we know that MIPS r2 & above support the sel field for the dmtc0
instruction, we don't bother special casing sel==0. Omiting the sel
field would assemble to exactly the same instruction as when we
explicitly specify that it equals zero.

Signed-off-by: Paul Burton <paul.burton@mips.com>
 2018-08-07 10:33:45 -07:00