Pull string hash improvements from George Spelvin:
"This series does several related things:
- Makes the dcache hash (fs/namei.c) useful for general kernel use.
(Thanks to Bruce for noticing the zero-length corner case)
- Converts the string hashes in <linux/sunrpc/svcauth.h> to use the
above.
- Avoids 64-bit multiplies in hash_64() on 32-bit platforms. Two
32-bit multiplies will do well enough.
- Rids the world of the bad hash multipliers in hash_32.
This finishes the job started in commit 689de1d6ca ("Minimal
fix-up of bad hashing behavior of hash_64()")
The vast majority of Linux architectures have hardware support for
32x32-bit multiply and so derive no benefit from "simplified"
multipliers.
The few processors that do not (68000, h8/300 and some models of
Microblaze) have arch-specific implementations added. Those
patches are last in the series.
- Overhauls the dcache hash mixing.
The patch in commit 0fed3ac866 ("namei: Improve hash mixing if
CONFIG_DCACHE_WORD_ACCESS") was an off-the-cuff suggestion.
Replaced with a much more careful design that's simultaneously
faster and better. (My own invention, as there was noting suitable
in the literature I could find. Comments welcome!)
- Modify the hash_name() loop to skip the initial HASH_MIX(). This
would let us salt the hash if we ever wanted to.
- Sort out partial_name_hash().
The hash function is declared as using a long state, even though
it's truncated to 32 bits at the end and the extra internal state
contributes nothing to the result. And some callers do odd things:
- fs/hfs/string.c only allocates 32 bits of state
- fs/hfsplus/unicode.c uses it to hash 16-bit unicode symbols not bytes
- Modify bytemask_from_count to handle inputs of 1..sizeof(long)
rather than 0..sizeof(long)-1. This would simplify users other
than full_name_hash"
Special thanks to Bruce Fields for testing and finding bugs in v1. (I
learned some humbling lessons about "obviously correct" code.)
On the arch-specific front, the m68k assembly has been tested in a
standalone test harness, I've been in contact with the Microblaze
maintainers who mostly don't care, as the hardware multiplier is never
omitted in real-world applications, and I haven't heard anything from
the H8/300 world"
* 'hash' of git://ftp.sciencehorizons.net/linux:
h8300: Add <asm/hash.h>
microblaze: Add <asm/hash.h>
m68k: Add <asm/hash.h>
<linux/hash.h>: Add support for architecture-specific functions
fs/namei.c: Improve dcache hash function
Eliminate bad hash multipliers from hash_32() and hash_64()
Change hash_64() return value to 32 bits
<linux/sunrpc/svcauth.h>: Define hash_str() in terms of hashlen_string()
fs/namei.c: Add hashlen_string() function
Pull out string hash to <linux/stringhash.h>
This will improve the performance of hash_32() and hash_64(), but due
to complete lack of multi-bit shift instructions on H8, performance will
still be bad in surrounding code.
Designing H8-specific hash algorithms to work around that is a separate
project. (But if the maintainers would like to get in touch...)
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: uclinux-h8-devel@lists.sourceforge.jp
Microblaze is an FPGA soft core that can be configured various ways.
If it is configured without a multiplier, the standard __hash_32()
will require a call to __mulsi3, which is a slow software loop.
Instead, use a shift-and-add sequence for the constant multiply.
GCC knows how to do this, but it's not as clever as some.
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Alistair Francis <alistair.francis@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
This is just the infrastructure; there are no users yet.
This is modelled on CONFIG_ARCH_RANDOM; a CONFIG_ symbol declares
the existence of <asm/hash.h>.
That file may define its own versions of various functions, and define
HAVE_* symbols (no CONFIG_ prefix!) to suppress the generic ones.
Included is a self-test (in lib/test_hash.c) that verifies the basics.
It is NOT in general required that the arch-specific functions compute
the same thing as the generic, but if a HAVE_* symbol is defined with
the value 1, then equality is tested.
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Philippe De Muyter <phdm@macq.eu>
Cc: linux-m68k@lists.linux-m68k.org
Cc: Alistair Francis <alistai@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: uclinux-h8-devel@lists.sourceforge.jp
In microMIPS kernels, handle_signal() sets the isa16 mode bit in the
vdso address so that the sigreturn trampolines (which are offset from
the VDSO) get executed as microMIPS.
However commit ebb5e78cc6 ("MIPS: Initial implementation of a VDSO")
changed the offsets to come from the VDSO image, which already have the
isa16 mode bit set correctly since they're extracted from the VDSO
shared library symbol table.
Drop the isa16 mode bit handling from handle_signal() to fix sigreturn
for cores which support both microMIPS and normal MIPS. This doesn't fix
microMIPS only cores, since the VDSO is still built for normal MIPS, but
thats a separate problem.
Fixes: ebb5e78cc6 ("MIPS: Initial implementation of a VDSO")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.4.x-
Patchwork: https://patchwork.linux-mips.org/patch/13348/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Avoid an aliasing issue causing a build error in VDSO:
In file included from include/linux/srcu.h:34:0,
from include/linux/notifier.h:15,
from ./arch/mips/include/asm/uprobes.h:9,
from include/linux/uprobes.h:61,
from include/linux/mm_types.h:13,
from ./arch/mips/include/asm/vdso.h:14,
from arch/mips/vdso/vdso.h:27,
from arch/mips/vdso/gettimeofday.c:11:
include/linux/workqueue.h: In function 'work_static':
include/linux/workqueue.h:186:2: error: dereferencing type-punned pointer will break strict-aliasing rules [-Werror=strict-aliasing]
return *work_data_bits(work) & WORK_STRUCT_STATIC;
^
cc1: all warnings being treated as errors
make[2]: *** [arch/mips/vdso/gettimeofday.o] Error 1
with a CONFIG_DEBUG_OBJECTS_WORK configuration and GCC 5.2.0. Include
`-fno-strict-aliasing' along with compiler options used, as required for
kernel code, fixing a problem present since the introduction of VDSO
with commit ebb5e78cc6 ("MIPS: Initial implementation of a VDSO").
Thanks to Tejun for diagnosing this properly!
Signed-off-by: Maciej W. Rozycki <macro@imgtec.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Fixes: ebb5e78cc6 ("MIPS: Initial implementation of a VDSO")
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.3+
Patchwork: https://patchwork.linux-mips.org/patch/13357/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The Hardware page Table Walker (HTW) is being misconfigured on 64-bit
kernels. The PWSize.PS (pointer size) bit determines whether pointers
within directories are loaded as 32-bit or 64-bit addresses, but was
never being set to 1 for 64-bit kernels where the unsigned long in pgd_t
is 64-bits wide.
This actually reduces rather than improves performance when the HTW is
enabled on P6600 since the HTW is initiated lots, but walks are all
aborted due I think to bad intermediate pointers.
Since we were already taking the width of the PTEs into account by
setting PWSize.PTEW, which is the left shift applied to the page table
index *in addition to* the native pointer size, we also need to reduce
PTEW by 1 when PS=1. This is done by calculating PTEW based on the
relative size of pte_t compared to pgd_t.
Finally in order for the HTW to be used when PS=1, the appropriate
XK/XS/XU bits corresponding to the different 64-bit segments need to be
set in PWCtl. We enable only XU for now to enable walking for XUSeg.
Supporting walking for XKSeg would be a bit more involved so is left for
a future patch. It would either require the use of a per-CPU top level
base directory if supported by the HTW (a bit like pgd_current but with
a second entry pointing at swapper_pg_dir), or the HTW would prepend bit
63 of the address to the global directory index which doesn't really
match how we split user and kernel page directories.
Fixes: cab25bc753 ("MIPS: Extend hardware table walking support to MIPS64")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13364/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Simplify the DSP instruction wrapper macros which use explicit encodings
for microMIPS and normal MIPS by using the new encoding macros and
removing duplication.
To me this makes it easier to read since it is much shorter, but it also
ensures .insn is used, preventing objdump disassembling the microMIPS
code as normal MIPS.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13314/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Hardcoded MIPS instruction encodings are provided for tlbinvf, mfhc0 &
mthc0 instructions, but microMIPS encodings are missing. I doubt any
microMIPS cores exist at present which support these instructions, but
the microMIPS encodings exist, and microMIPS cores may support them in
the future. Add the missing microMIPS encodings using the new macros.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13313/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
When the toolchain doesn't support MSA we encode MSA instructions
explicitly in assembly. Unfortunately we use .word for both MIPS and
microMIPS encodings which is wrong, since 32-bit microMIPS instructions
are made up from a pair of halfwords.
- The most significant halfword always comes first, so for little endian
builds the halves will be emitted in the wrong order.
- 32-bit alignment isn't guaranteed, so the assembler may insert a
16-bit nop instruction to pad the instruction stream to a 32-bit
boundary.
Use the new instruction encoding macros to encode microMIPS MSA
instructions correctly.
Fixes: d96cc3d1ec ("MIPS: Add microMIPS MSA support.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <Paul.Burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13312/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Toolchains may be used which support microMIPS but not VZ instructions
(i.e. binutis 2.22 & 2.23), so extend the explicitly encoded versions of
the guest COP0 register & guest TLB access macros to support microMIPS
encodings too, using the new macros.
This prevents non-microMIPS instructions being executed in microMIPS
mode during CPU probe on cores supporting VZ (e.g. M5150), which cause
reserved instruction exceptions early during boot.
Fixes: bad50d7925 ("MIPS: Fix VZ probe gas errors with binutils <2.24")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13311/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
To allow simplification of macros which use inline assembly to
explicitly encode instructions, add a few simple abstractions to
mipsregs.h which expand to specific microMIPS or normal MIPS encodings
depending on what type of kernel is being built:
_ASM_INSN_IF_MIPS(_enc) : Emit a 32bit MIPS instruction if microMIPS is
not enabled.
_ASM_INSN32_IF_MM(_enc) : Emit a 32bit microMIPS instruction if enabled.
_ASM_INSN16_IF_MM(_enc) : Emit a 16bit microMIPS instruction if enabled.
The macros can be used one after another since the MIPS / microMIPS
macros are mutually exclusive, for example:
__asm__ __volatile__(
".set push\n\t"
".set noat\n\t"
"# mfgc0 $1, $%1, %2\n\t"
_ASM_INSN_IF_MIPS(0x40610000 | %1 << 11 | %2)
_ASM_INSN32_IF_MM(0x002004fc | %1 << 16 | %2 << 11)
"move %0, $1\n\t"
".set pop"
: "=r" (__res)
: "i" (source), "i" (sel));
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13310/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The versions of the __write_{32,64}bit_gc0_register() macros for when
there is no virt support in the assembler use the "J" inline asm
constraint to allow integer zero, but this needs to be accompanied by
the "z" formatting string so that it turns into $0. Fix both macros to
do this.
Fixes: bad50d7925 ("MIPS: Fix VZ probe gas errors with binutils <2.24")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/13289/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Commit 12822570a2 ("MIPS: Separate XPA CPU feature into LPA and MVH")
wasn't fully applied, possibly due to a conflict with commit
f270d881fa ("MIPS: Detect MIPSr6 Virtual Processor support"). This
left decode_config5() referring to the non-existent MIPS_CPU_XPA, which
breaks the build when XPA is enabled:
arch/mips/kernel/cpu-probe.c In function ‘decode_config5’:
arch/mips/kernel/cpu-probe.c:838:17: error: ‘MIPS_CPU_XPA’ undeclared (first use in this function)
c->options |= MIPS_CPU_XPA;
^
Apply the missing hunk, dropping the CONFIG_XPA ifdef and setting the
MIPS_CPU_MVH option when Config5.MVH is set.
Fixes: 12822570a2 ("MIPS: Separate XPA CPU feature into LPA and MVH")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Link: https://patchwork.linux-mips.org/patch/13112/
Patchwork: https://patchwork.linux-mips.org/patch/13277/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull UML updates from Richard Weinberger:
"This contains a nice FPU fixup from Eli Cooper for UML"
* 'for-linus-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: add extended processor state save/restore support
um: extend fpstate to _xstate to support YMM registers
um: fix FPU state preservation around signal handlers
The do_brk() and vm_brk() return value was "unsigned long" and returned
the starting address on success, and an error value on failure. The
reasons are entirely historical, and go back to it basically behaving
like the mmap() interface does.
However, nobody actually wanted that interface, and it causes totally
pointless IS_ERR_VALUE() confusion.
What every single caller actually wants is just the simpler integer
return of zero for success and negative error number on failure.
So just convert to that much clearer and more common calling convention,
and get rid of all the IS_ERR_VALUE() uses wrt vm_brk().
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 platform driver updates from Darren Hart:
"Mostly minor updates and cleanups. One new power management
controller driver for Intel Core SoCs.
platform/x86:
- Add PMC Driver for Intel Core SoC
dell-rbtn:
- Ignore ACPI notifications if device is suspended
thinkpad_acpi:
- save kbdlight state on suspend and restore it on resume
intel_menlow:
- reduce code duplication
asus-wmi:
- provide access to ALS control
ideapad-laptop:
- add a new WMI string for ESC key
surfacepro3_button:
- Add a warning when switching to tablet mode
sony-laptop:
- Avoid oops on module unload for older laptops
intel_telemetry:
- Constify telemetry_core_ops structures
fujitsu-laptop:
- Use IS_ENABLED() instead of checking for built-in or module
asus-laptop:
- correct error handling in sysfs_acpi_set
- remove redundant initializers
- correct error handling in asus_read_brightness()
fujitsu-laptop:
- Support radio LED"
* tag 'platform-drivers-x86-v4.7-1' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86:
platform/x86: Add PMC Driver for Intel Core SoC
dell-rbtn: Ignore ACPI notifications if device is suspended
thinkpad_acpi: save kbdlight state on suspend and restore it on resume
intel_menlow: reduce code duplication
asus-wmi: provide access to ALS control
ideapad-laptop: add a new WMI string for ESC key
surfacepro3_button: Add a warning when switching to tablet mode
sony-laptop: Avoid oops on module unload for older laptops
intel_telemetry: Constify telemetry_core_ops structures
fujitsu-laptop: Use IS_ENABLED() instead of checking for built-in or module
asus-laptop: correct error handling in sysfs_acpi_set
asus-laptop: remove redundant initializers
asus-laptop: correct error handling in asus_read_brightness()
fujitsu-laptop: Support radio LED
Pull second batch of KVM updates from Radim Krčmář:
"General:
- move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat (kvm_stat
had nothing to do with QEMU in the first place -- the tool only
interprets debugfs)
- expose per-vm statistics in debugfs and support them in kvm_stat
(KVM always collected per-vm statistics, but they were summarised
into global statistics)
x86:
- fix dynamic APICv (VMX was improperly configured and a guest could
access host's APIC MSRs, CVE-2016-4440)
- minor fixes
ARM changes from Christoffer Dall:
- new vgic reimplementation of our horribly broken legacy vgic
implementation. The two implementations will live side-by-side
(with the new being the configured default) for one kernel release
and then we'll remove the legacy one.
- fix for a non-critical issue with virtual abort injection to guests"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (70 commits)
tools: kvm_stat: Add comments
tools: kvm_stat: Introduce pid monitoring
KVM: Create debugfs dir and stat files for each VM
MAINTAINERS: Add kvm tools
tools: kvm_stat: Powerpc related fixes
tools: Add kvm_stat man page
tools: Add kvm_stat vm monitor script
kvm:vmx: more complete state update on APICv on/off
KVM: SVM: Add more SVM_EXIT_REASONS
KVM: Unify traced vector format
svm: bitwise vs logical op typo
KVM: arm/arm64: vgic-new: Synchronize changes to active state
KVM: arm/arm64: vgic-new: enable build
KVM: arm/arm64: vgic-new: implement mapped IRQ handling
KVM: arm/arm64: vgic-new: Wire up irqfd injection
KVM: arm/arm64: vgic-new: Add vgic_v2/v3_enable
KVM: arm/arm64: vgic-new: vgic_init: implement map_resources
KVM: arm/arm64: vgic-new: vgic_init: implement vgic_init
KVM: arm/arm64: vgic-new: vgic_init: implement vgic_create
KVM: arm/arm64: vgic-new: vgic_init: implement kvm_vgic_hyp_init
...
