Commit Graph

601716 Commits

Author SHA1 Message Date
Tony Lindgren
44e7475d40 ARM: OMAP2+: Fix build if CONFIG_SMP is not set
Looks like I only partially fixed up things if CONFIG_SMP
is not set for the recent kexec changes. We don't have
boot_secondary available without SMP as reported by Arnd.

Fixes: 0573b957fc ("ARM: OMAP4+: Prevent CPU1 related hang with kexec")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-27 23:30:02 -07:00
Tony Lindgren
3696203c47 ARM: OMAP4+: Allow kexec on SMP variants
Kexec needs omap4_cpu_kill, otherwise kexec will produce on SMP:

kexec_load failed: Invalid argument

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Tested-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-22 22:57:02 -07:00
Tony Lindgren
3251885285 ARM: OMAP4+: Reset CPU1 properly for kexec
We need to reset CPU1 properly for kexec when booting different
kernel versions. Otherwise CPU1 will attempt to boot the the
previous kernel's start_secondary(). Note that the restctrl
register is different from the low-power mode wakeup register
CPU1_WAKEUP_NS_PA_ADDR. We need to configure both.

Let's fix the issue by defining SoC specific data to initialize
things in a more generic way. And let's also standardize omap-smp.c
to use soc_is instead of cpu_is while at it.

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Tested-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-22 22:55:53 -07:00
Tony Lindgren
0573b957fc ARM: OMAP4+: Prevent CPU1 related hang with kexec
Kexec booted kernels on omap4 will hang early during the boot if the
booted kernel is different version from the previous kernel.

This is because the previous kernel may have configured low-power mode
using CPU1_WAKEUP_NS_PA_ADDR. In that case it points to the previous
kernel's omap4_secondary_startup(), and CPU1 can be in low power mode
from the previous kernel. When the new kernel configures the CPU1
clockdomain, CPU1 can wake from low power state prematurely during
omap44xx_clockdomains_init() running random code.

Let's fix the issue by configuring CPU1_WAKEUP_NS_PA_ADDR before we
call omap44xx_clockdomains_init(). Note that this is very early during
the init, and we will do proper CPU1 reset during SMP init a bit later
on in omap4_smp_prepare_cpus(). And we need to do this when SMP is
not enabled as the previous kernel may have had it enabled.

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Tested-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-22 22:55:51 -07:00
Tony Lindgren
f4b9f40ae9 ARM: OMAP4+: Initialize SAR RAM base early for proper CPU1 reset for kexec
Prepare things for making kexec work on SMP omap variants by initializing
SARM RAM base early. This allows us to configure CPU1 for kexec in case
the previous kernel has put CPU1 in low power mode.

Note that this should not prevent moving other SAR RAM code to live
under drivers. However for kexec, we will need this very early.

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Tested-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-22 22:55:47 -07:00
Tony Lindgren
99eb45f98c Merge commit 'c0053bd50af5' into omap-for-v4.8/soc 2016-06-22 22:55:18 -07:00
Keerthy
218092afa0 ARM: dts: am43xx: Remove wrongly defined RSTST offset for PER Domain
As per the TRM: http://www.ti.com/lit/ug/spruh73m/spruh73m.pdf
offset 0x4 is reserved for PRM_PER. Hence removing the wrongly
defined address offset.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-22 03:33:25 -07:00
Ben Dooks
41dc54830d ARM: OMAP: make ti81xx_rtc_hwmod static
The ti81xx_rtc_hwmod is not exported, or declared outside the file
arch/arm/mach-omap2/omap_hwmod_81xx_data.c so make it static to
avoid the following warning:

arch/arm/mach-omap2/omap_hwmod_81xx_data.c:246:19: warning: symbol 'ti81xx_rtc_hwmod' was not declared. Should it be static?

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-22 03:05:18 -07:00
Keerthy
b00ccf5b68 ARM: AM43XX: hwmod: Fix RSTST register offset for pruss
pruss hwmod RSTST register wrongly points to PWRSTCTRL register in case of
am43xx. Fix the RSTST register offset value.

This can lead to setting of wrong power state values for PER domain.

Fixes: 1c7e224d ("ARM: OMAP2+: hwmod: AM335x: runtime register update")
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-22 02:55:44 -07:00
Tomi Valkeinen
05a7ac7266 ARM: DRA7: hwmod: remove DSS addresses from hwmod
The addresses for DSS are provided in the DT data, so they can be
removed from the hwmod.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 05:10:52 -07:00
Vignesh R
cab33b0e93 ARM: DRA7: hwmod: Remove QSPI address space entry from hwmod
QSPI address space information is passed from device tree. Therefore
remove legacy way of passing address space via hwmod data.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 05:09:46 -07:00
Peter Ujfalusi
3774bec74e ARM: OMAP2+: McBSP: Remove the old iclk allow/deny idle code
The new pdata callback (force_ick_on) is now used by the driver and the old
callback related code can be removed.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 05:07:25 -07:00
Peter Ujfalusi
bbfa26c530 ASoC: omap-mcbsp: sidetone: Use the new callback for iclk handling
The McBSP sidetone (in OMAP3 McBSP2 and 3 module) is working with the
module's interface clock. When the sidetone is enabled the iclk must not
idle because it will result in choppy sidetone.
Switch to use the new callback for handling the iclk allow/deny idle
configuration.
For this the driver needs to get the module's ick clock and pass the clk
pointer to the callback.
In DT boot, the pdata-quirk is going to set up the callback for the driver
so save it if it is set in the pdata of the device.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 05:07:24 -07:00
Peter Ujfalusi
6610d3571b ASoC: omap-mcbsp: Rename omap_mcbsp_sysfs_remove() to omap_mcbsp_cleanup()
The function will do more then removing the sysfs files in the future.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 05:07:24 -07:00
Peter Ujfalusi
c26c84c92b ARM: OMAP3: pdata-quirks: Add support for McBSP2/3 sidetone handling
McBSP2/3 module's sidetone module operates using the module's ICLK clock.
When the Sidetone is in use the interface clock of the module must not
idle. To prevent the iclk idling the driver expects to have pdata callback
to call. With this patch the callback is going to be set up for DT boot
also.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 05:07:23 -07:00
Peter Ujfalusi
53ae95f6d5 ARM: OMAP3: McBSP: New callback for McBSP2/3 ICLK idle configuration
McBSP2/3 module's sidetone module operates using the module's ICLK clock.
When the Sidetone is in use the interface clock of the module must not
idle. The new callback expects to receive the *clk of the module's ick and
not the id number of the McBSP. This will allow us more cleanups and going
to simplify the ICLK handling.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 05:07:22 -07:00
Peter Ujfalusi
3b80c9bef8 ARM: OMAP3: hwmod data: Fix McBSP2/3 sidetone data
The McBSPLP's sidetone main clock is the McBSPLP's ICLK, not FCLK as the
sidetone only receives the ICLK from the main McBSP module.
Since the McBSP and sidetone is using the very same clock from PRCM level
the sidetone must not have the prcm section to check the clock status since
the sidetone is only used when McBSP is already configured.
If two separate hwmods looking at the same bit and they would use
pm_runtime in nested way (as it must happen with McBSP and it's ST module)
the hwmod would warn, because the idlest will not match what it is expected
after enable/disable of the clocks.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 05:07:21 -07:00
Franklin S Cooper Jr
015d859193 ARM: AM335x/AM437x: hwmod: Remove eQEP, ePWM and eCAP hwmod entries
Devices that utilize the OCP registers and/or PRCM registers and
register bit fields should be modeled using hwmod. Since eQEP, ePWM and
eCAP don't fall under this category, remove their hwmod entries.

Instead these clocks simply use the clock that is passed through by its
parent PWMSS. Therefore, PWMSS handles the clock for itself and its
subdevices.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 05:02:34 -07:00
Andrea Gelmini
078508f85e ARM: OMAP2+: Fix typo in sdrc.h
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 04:17:07 -07:00
Andrea Gelmini
f733e7c0e0 ARM: OMAP2+: Fix typo in omap_device.c
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 04:16:43 -07:00
Andrea Gelmini
6eedfcbea8 ARM: OMAP2+: Fix typo in omap4-common.c
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 04:16:05 -07:00
Andrea Gelmini
df85ac825c ARM: OMAP2+: Fix typo in mux34xx.c
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 04:15:33 -07:00
Andrea Gelmini
3c4d4c2033 ARM: OMAP2+: Fix typo in cm3xxx.c
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 04:14:37 -07:00
Andrea Gelmini
811b602431 ARM: OMAP1: Fix typo in mtd-xip.h
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 04:13:55 -07:00
Andrea Gelmini
566ad81f13 ARM: OMAP1: Fix typo in fiq.c
Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 04:10:43 -07:00
Franklin S Cooper Jr
22a15e6ffa clk: ti: am335x/am4372: Add tbclk to pwm node
Add tblck to the pwm nodes. This insures that the ehrpwm driver has access
to the time-based clk.

Do not remove similar entries for ehrpwm node. Later patches will switch
from using ehrpwm node name to pwm. But to maintain ABI compatibility we
shouldn't remove the old entries.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-10 03:25:04 -07:00
Tony Lindgren
68ada6bd11 Merge branch 'peter/for-4.8_omapdss_part1' of https://github.com/omap-audio/linux-audio into omap-for-v4.8/soc 2016-06-09 00:44:00 -07:00
Peter Ujfalusi
f8e0db9722 ARM: OMAP2: Use the platform_data header for omapdss
Instead of the full omapdss internal header, include only the platform_data
header.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2016-06-03 16:01:01 +03:00
Peter Ujfalusi
60fc4bab91 video/platform_data: omapdss: Create new header file for platform data
Create a new header file for platform data used by omapdss.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
2016-06-03 16:00:45 +03:00
Peter Ujfalusi
c270e89bf2 ARM/video: omap2: Move omap_display_init declaration to mach-omap2/display.h
The omap_display_init() is implemented in the mach-omap2/display.c so the
declaration should have been there as well.
Change the board files to include display.h to avoid build breakage at the
same time.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2016-06-03 16:00:31 +03:00
Peter Ujfalusi
6697ad24b1 ARM: OMAP: rx51-video: Do not set TV connector_type
OMAP_DSS_VENC_TYPE_COMPOSITE is 0. There is no need to explicitly set the
connector_type.
This change is needed for the omapdss header cleanup.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
2016-06-03 15:59:13 +03:00
Linus Torvalds
1a695a905c Linux 4.7-rc1 2016-05-29 09:29:24 -07:00
George Spelvin
e0ab7af9bd hash_string: Fix zero-length case for !DCACHE_WORD_ACCESS
The self-test was updated to cover zero-length strings; the function
needs to be updated, too.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Fixes: fcfd2fbf22 ("fs/namei.c: Add hashlen_string() function")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-29 07:33:47 -07:00
George Spelvin
f2a031b66e Rename other copy of hash_string to hashlen_string
The original name was simply hash_string(), but that conflicted with a
function with that name in drivers/base/power/trace.c, and I decided
that calling it "hashlen_" was better anyway.

But you have to do it in two places.

[ This caused build errors for architectures that don't define
  CONFIG_DCACHE_WORD_ACCESS   - Linus ]

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: fcfd2fbf22 ("fs/namei.c: Add hashlen_string() function")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28 22:34:33 -07:00
Mikulas Patocka
037369b872 hpfs: implement the show_options method
The HPFS filesystem used generic_show_options to produce string that is
displayed in /proc/mounts.  However, there is a problem that the options
may disappear after remount.  If we mount the filesystem with option1
and then remount it with option2, /proc/mounts should show both option1
and option2, however it only shows option2 because the whole option
string is replaced with replace_mount_options in hpfs_remount_fs.

To fix this bug, implement the hpfs_show_options function that prints
options that are currently selected.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28 16:50:24 -07:00
Mikulas Patocka
01d6e08711 affs: fix remount failure when there are no options changed
Commit c8f33d0bec ("affs: kstrdup() memory handling") checks if the
kstrdup function returns NULL due to out-of-memory condition.

However, if we are remounting a filesystem with no change to
filesystem-specific options, the parameter data is NULL.  In this case,
kstrdup returns NULL (because it was passed NULL parameter), although no
out of memory condition exists.  The mount syscall then fails with
ENOMEM.

This patch fixes the bug.  We fail with ENOMEM only if data is non-NULL.

The patch also changes the call to replace_mount_options - if we didn't
pass any filesystem-specific options, we don't call
replace_mount_options (thus we don't erase existing reported options).

Fixes: c8f33d0bec ("affs: kstrdup() memory handling")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org	# v4.1+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28 16:50:24 -07:00
Mikulas Patocka
44d51706b4 hpfs: fix remount failure when there are no options changed
Commit ce657611ba ("hpfs: kstrdup() out of memory handling") checks if
the kstrdup function returns NULL due to out-of-memory condition.

However, if we are remounting a filesystem with no change to
filesystem-specific options, the parameter data is NULL.  In this case,
kstrdup returns NULL (because it was passed NULL parameter), although no
out of memory condition exists.  The mount syscall then fails with
ENOMEM.

This patch fixes the bug.  We fail with ENOMEM only if data is non-NULL.

The patch also changes the call to replace_mount_options - if we didn't
pass any filesystem-specific options, we don't call
replace_mount_options (thus we don't erase existing reported options).

Fixes: ce657611ba ("hpfs: kstrdup() out of memory handling")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28 16:50:24 -07:00
Linus Torvalds
4029632c34 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull more MIPS updates from Ralf Baechle:
 "This is the secondnd batch of MIPS patches for 4.7. Summary:

  CPS:
   - Copy EVA configuration when starting secondary VPs.

  EIC:
   - Clear Status IPL.

  Lasat:
   - Fix a few off by one bugs.

  lib:
   - Mark intrinsics notrace.  Not only are the intrinsics
     uninteresting, it would cause infinite recursion.

  MAINTAINERS:
   - Add file patterns for MIPS BRCM device tree bindings.
   - Add file patterns for mips device tree bindings.

  MT7628:
   - Fix MT7628 pinmux typos.
   - wled_an pinmux gpio.
   - EPHY LEDs pinmux support.

  Pistachio:
   - Enable KASLR

  VDSO:
   - Build microMIPS VDSO for microMIPS kernels.
   - Fix aliasing warning by building with `-fno-strict-aliasing' for
     debugging but also tracing them might result in recursion.

  Misc:
   - Add missing FROZEN hotplug notifier transitions.
   - Fix clk binding example for varioius PIC32 devices.
   - Fix cpu interrupt controller node-names in the DT files.
   - Fix XPA CPU feature separation.
   - Fix write_gc0_* macros when writing zero.
   - Add inline asm encoding helpers.
   - Add missing VZ accessor microMIPS encodings.
   - Fix little endian microMIPS MSA encodings.
   - Add 64-bit HTW fields and fix its configuration.
   - Fix sigreturn via VDSO on microMIPS kernel.
   - Lots of typo fixes.
   - Add definitions of SegCtl registers and use them"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (49 commits)
  MIPS: Add missing FROZEN hotplug notifier transitions
  MIPS: Build microMIPS VDSO for microMIPS kernels
  MIPS: Fix sigreturn via VDSO on microMIPS kernel
  MIPS: devicetree: fix cpu interrupt controller node-names
  MIPS: VDSO: Build with `-fno-strict-aliasing'
  MIPS: Pistachio: Enable KASLR
  MIPS: lib: Mark intrinsics notrace
  MIPS: Fix 64-bit HTW configuration
  MIPS: Add 64-bit HTW fields
  MAINTAINERS: Add file patterns for mips device tree bindings
  MAINTAINERS: Add file patterns for mips brcm device tree bindings
  MIPS: Simplify DSP instruction encoding macros
  MIPS: Add missing tlbinvf/XPA microMIPS encodings
  MIPS: Fix little endian microMIPS MSA encodings
  MIPS: Add missing VZ accessor microMIPS encodings
  MIPS: Add inline asm encoding helpers
  MIPS: Spelling fix lets -> let's
  MIPS: VR41xx: Fix typo
  MIPS: oprofile: Fix typo
  MIPS: math-emu: Fix typo
  ...
2016-05-28 16:41:39 -07:00
Guenter Roeck
d66492bce1 fs: fix binfmt_aout.c build error
Various builds (such as i386:allmodconfig) fail with

  fs/binfmt_aout.c:133:2: error: expected identifier or '(' before 'return'
  fs/binfmt_aout.c:134:1: error: expected identifier or '(' before '}' token

[ Oops. My bad, I had stupidly thought that "allmodconfig" covered this
  on x86-64 too, but it obviously doesn't.  Egg on my face.  - Linus ]

Fixes: 5d22fc25d4 ("mm: remove more IS_ERR_VALUE abuses")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28 16:34:59 -07:00
Linus Torvalds
7e0fb73c52 Merge branch 'hash' of git://ftp.sciencehorizons.net/linux
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>
2016-05-28 16:15:25 -07:00
George Spelvin
4684fe9530 h8300: Add <asm/hash.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
2016-05-28 15:48:58 -04:00
George Spelvin
7b13277b68 microblaze: Add <asm/hash.h>
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>
2016-05-28 15:48:58 -04:00
George Spelvin
14c44b95b3 m68k: Add <asm/hash.h>
This provides a multiply by constant GOLDEN_RATIO_32 = 0x61C88647
for the original mc68000, which lacks a 32x32-bit multiply instruction.

Yes, the amount of optimization effort put in is excessive. :-)

Shift-add chain found by Yevgen Voronenko's Hcub algorithm at
http://spiral.ece.cmu.edu/mcm/gen.html

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
2016-05-28 15:48:57 -04:00
George Spelvin
468a942852 <linux/hash.h>: Add support for architecture-specific functions
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
2016-05-28 15:48:31 -04:00
George Spelvin
2a18da7a9c fs/namei.c: Improve dcache hash function
Patch 0fed3ac866 improved the hash mixing, but the function is slower
than necessary; there's a 7-instruction dependency chain (10 on x86)
each loop iteration.

Word-at-a-time access is a very tight loop (which is good, because
link_path_walk() is one of the hottest code paths in the entire kernel),
and the hash mixing function must not have a longer latency to avoid
slowing it down.

There do not appear to be any published fast hash functions that:
1) Operate on the input a word at a time, and
2) Don't need to know the length of the input beforehand, and
3) Have a single iterated mixing function, not needing conditional
   branches or unrolling to distinguish different loop iterations.

One of the algorithms which comes closest is Yann Collet's xxHash, but
that's two dependent multiplies per word, which is too much.

The key insights in this design are:

1) Barring expensive ops like multiplies, to diffuse one input bit
   across 64 bits of hash state takes at least log2(64) = 6 sequentially
   dependent instructions.  That is more cycles than we'd like.
2) An operation like "hash ^= hash << 13" requires a second temporary
   register anyway, and on a 2-operand machine like x86, it's three
   instructions.
3) A better use of a second register is to hold a two-word hash state.
   With careful design, no temporaries are needed at all, so it doesn't
   increase register pressure.  And this gets rid of register copying
   on 2-operand machines, so the code is smaller and faster.
4) Using two words of state weakens the requirement for one-round mixing;
   we now have two rounds of mixing before cancellation is possible.
5) A two-word hash state also allows operations on both halves to be
   done in parallel, so on a superscalar processor we get more mixing
   in fewer cycles.

I ended up using a mixing function inspired by the ChaCha and Speck
round functions.  It is 6 simple instructions and 3 cycles per iteration
(assuming multiply by 9 can be done by an "lea" instruction):

		x ^= *input++;
	y ^= x;	x = ROL(x, K1);
	x += y;	y = ROL(y, K2);
	y *= 9;

Not only is this reversible, two consecutive rounds are reversible:
if you are given the initial and final states, but not the intermediate
state, it is possible to compute both input words.  This means that at
least 3 words of input are required to create a collision.

(It also has the property, used by hash_name() to avoid a branch, that
it hashes all-zero to all-zero.)

The rotate constants K1 and K2 were found by experiment.  The search took
a sample of random initial states (I used 1023) and considered the effect
of flipping each of the 64 input bits on each of the 128 output bits two
rounds later.  Each of the 8192 pairs can be considered a biased coin, and
adding up the Shannon entropy of all of them produces a score.

The best-scoring shifts also did well in other tests (flipping bits in y,
trying 3 or 4 rounds of mixing, flipping all 64*63/2 pairs of input bits),
so the choice was made with the additional constraint that the sum of the
shifts is odd and not too close to the word size.

The final state is then folded into a 32-bit hash value by a less carefully
optimized multiply-based scheme.  This also has to be fast, as pathname
components tend to be short (the most common case is one iteration!), but
there's some room for latency, as there is a fair bit of intervening logic
before the hash value is used for anything.

(Performance verified with "bonnie++ -s 0 -n 1536:-2" on tmpfs.  I need
a better benchmark; the numbers seem to show a slight dip in performance
between 4.6.0 and this patch, but they're too noisy to quote.)

Special thanks to Bruce fields for diligent testing which uncovered a
nasty fencepost error in an earlier version of this patch.

[checkpatch.pl formatting complaints noted and respectfully disagreed with.]

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Tested-by: J. Bruce Fields <bfields@redhat.com>
2016-05-28 15:45:29 -04:00
George Spelvin
ef703f49a6 Eliminate bad hash multipliers from hash_32() and hash_64()
The "simplified" prime multipliers made very bad hash functions, so get rid
of them.  This completes the work of 689de1d6ca.

To avoid the inefficiency which was the motivation for the "simplified"
multipliers, hash_64() on 32-bit systems is changed to use a different
algorithm.  It makes two calls to hash_32() instead.

drivers/media/usb/dvb-usb-v2/af9015.c uses the old GOLDEN_RATIO_PRIME_32
for some horrible reason, so it inherits a copy of the old definition.

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Antti Palosaari <crope@iki.fi>
Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
2016-05-28 15:42:51 -04:00
George Spelvin
92d567740f Change hash_64() return value to 32 bits
That's all that's ever asked for, and it makes the return
type of hash_long() consistent.

It also allows (upcoming patch) an optimized implementation
of hash_64 on 32-bit machines.

I tried adding a BUILD_BUG_ON to ensure the number of bits requested
was never more than 32 (most callers use a compile-time constant), but
adding <linux/bug.h> to <linux/hash.h> breaks the tools/perf compiler
unless tools/perf/MANIFEST is updated, and understanding that code base
well enough to update it is too much trouble.  I did the rest of an
allyesconfig build with such a check, and nothing tripped.

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
2016-05-28 15:42:51 -04:00
George Spelvin
917ea166f4 <linux/sunrpc/svcauth.h>: Define hash_str() in terms of hashlen_string()
Finally, the first use of previous two patches: eliminate the
separate ad-hoc string hash functions in the sunrpc code.

Now hash_str() is a wrapper around hash_string(), and hash_mem() is
likewise a wrapper around full_name_hash().

Note that sunrpc code *does* call hash_mem() with a zero length, which
is why the previous patch needed to handle that in full_name_hash().
(Thanks, Bruce, for finding that!)

This also eliminates the only caller of hash_long which asks for
more than 32 bits of output.

The comment about the quality of hashlen_string() and full_name_hash()
is jumping the gun by a few patches; they aren't very impressive now,
but will be improved greatly later in the series.

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Tested-by: J. Bruce Fields <bfields@redhat.com>
Acked-by: J. Bruce Fields <bfields@redhat.com>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: linux-nfs@vger.kernel.org
2016-05-28 15:42:50 -04:00
George Spelvin
fcfd2fbf22 fs/namei.c: Add hashlen_string() function
We'd like to make more use of the highly-optimized dcache hash functions
throughout the kernel, rather than have every subsystem create its own,
and a function that hashes basic null-terminated strings is required
for that.

(The name is to emphasize that it returns both hash and length.)

It's actually useful in the dcache itself, specifically d_alloc_name().
Other uses in the next patch.

full_name_hash() is also tweaked to make it more generally useful:
1) Take a "char *" rather than "unsigned char *" argument, to
   be consistent with hash_name().
2) Handle zero-length inputs.  If we want more callers, we don't want
   to make them worry about corner cases.

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
2016-05-28 15:42:50 -04:00
George Spelvin
f4bcbe792b Pull out string hash to <linux/stringhash.h>
... so they can be used without the rest of <linux/dcache.h>

The hashlen_* macros will make sense next patch.

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
2016-05-28 15:42:40 -04:00