601719 Commits

Author SHA1 Message Date
Bartlomiej Zolnierkiewicz
d7d7115d49 clk: samsung: exynos5433: add CPU clocks configuration data and instantiate CPU clocks
Add the CPU clocks configuration data and instantiate the CPU clocks
type for Exynos5433.

Cc: Kukjin Kim <kgene@kernel.org>
CC: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:21 +02:00
Bartlomiej Zolnierkiewicz
53f69967dc clk: samsung: cpu: prepare for adding Exynos5433 CPU clocks
Exynos5433 uses different register layout for CPU clock registers
than earlier SoCs so add new code for handling this layout.  Also
add new CLK_CPU_HAS_E5433_REGS_LAYOUT flag to request using it.

There should be no functional change resulting from this patch.

Cc: Kukjin Kim <kgene@kernel.org>
CC: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:20 +02:00
Bartlomiej Zolnierkiewicz
0c0cd59a4c clk: samsung: exynos5433: prepare for adding CPU clocks
Open-code samsung_cmu_register_one() calls for CMU_APOLLO and
CMU_ATLAS setup code as a preparation for adding CPU clocks
support for Exynos5433.

There should be no functional change resulting from this patch.

Cc: Kukjin Kim <kgene@kernel.org>
CC: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:19 +02:00
Krzysztof Kozlowski
f4f4dd0c45 clk: samsung: Suppress unbinding to prevent theoretical attacks
Although unbinding a driver requires root privileges but it still might
be used theoretically in certain attacks (by triggering NULL pointer
exception or memory corruption if driver does not provide proper remove
callbacks or core does not handle it).

Samsung clock drivers are essential for system operation so their
removal is not expected. More over, the Exynos3250 ISP clock driver does
not implement remove() driver callback and it is not buildable as
modules.

Suppress the unbind interface for Exynos3250 ISP and S3C2410 DCLK clock
drivers.

Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:18 +02:00
Javier Martinez Canillas
34cba90037 clk: samsung: exynos5420: Set ID for aclk333 gate clock
The aclk333 clock needs to be ungated during the MFC power domain switch,
so set the clock ID to allow the Exynos power domain logic to lookup this
clock if is defined in the MFC PD device tree node.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:17 +02:00
Krzysztof Kozlowski
41743a19b6 clk: samsung: exynos5410: Add TMU clock
Add clock for TMU to the Exynos5410 clock driver.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:16 +02:00
Krzysztof Kozlowski
31d3953f82 clk: samsung: exynos5410: Add I2C, HSI2C and RTC clocks
Add clocks for I2C, USI (HSI2C) and RTC to the Exynos5410 clock driver.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:16 +02:00
Krzysztof Kozlowski
1ebfb67de8 clk: samsung: exynos5410: Add serial3, USB and PWM clocks
Just like other Exynos5 family SoCs, this one has four UARTs. Add
missing UART3 clocks to the Exynos5410 clock driver.

Add clocks for USB and PWM.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:15 +02:00
Krzysztof Kozlowski
334393366f clk: samsung: exynos3250: Move PLL rates data to init section
The arrays with initialization data of PLLs can be moved to initconst
section because they are referenced only from other initconst-level
symbols.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:14 +02:00
Krzysztof Kozlowski
4dbf01b8df clk: samsung: Fully constify mux parent names
The PNAME macro defines array of strings for names of mux parents.
Although the strings itself were const but pointers to them were not thus
this data resided in initdata. Make this an array of const pointers to
const strings and move to initconst section.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:13 +02:00
Krzysztof Kozlowski
1d3f15a89e clk: samsung: exynos5250: Move sleep init function to init section
The exynos5250_clk_sleep_init() function can be moved to init section
because it is referenced only from other init-level calls.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:12 +02:00
Krzysztof Kozlowski
ebd217e165 clk: samsung: exynos5420: Move sleep init function and PLL data to init section
The exynos5420_clk_sleep_init() function and arrays with initialization
data of PLLs can be moved to init section because they are referenced
only from other init-level symbols.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:11 +02:00
Krzysztof Kozlowski
402b7cebf2 clk: samsung: exynos5433: Move PLL rates data to init section
The arrays with initialization data of PLLs can be moved to initconst
section because they are referenced only from other initconst-level
symbols.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:11 +02:00
Krzysztof Kozlowski
a6cd1fbc4b clk: samsung: exynos5433: Constify all clock initializers
All of initialization data can be made const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:10 +02:00
Krzysztof Kozlowski
a3618933c1 clk: samsung: exynos7: Constify all clock initializers
All of initialization data can be made const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:09 +02:00
Krzysztof Kozlowski
880c81b3b6 clk: samsung: exynos5440: Constify all clock initializers
All of initialization data can be made const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:08 +02:00
Krzysztof Kozlowski
ad98c64fbb clk: samsung: exynos5420: Constify all clock initializers
All of initialization data can be made const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:07 +02:00
Krzysztof Kozlowski
408860ba53 clk: samsung: exynos5410: Constify all clock initializers
All of initialization data can be made const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:07 +02:00
Krzysztof Kozlowski
c10d80f8e1 clk: samsung: exynos5260: Constify all clock initializers
All of initialization data can be made const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:06 +02:00
Krzysztof Kozlowski
5b37e8494d clk: samsung: exynos5250: Constify all clock initializers
All of initialization data can be made const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:05 +02:00
Krzysztof Kozlowski
ccd12b5cd6 clk: samsung: exynos4415: Move PLL rates data to init section
The arrays with initialization data of PLLs can be moved to initconst
section because they are referenced only from other initconst-level
symbols.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:04 +02:00
Krzysztof Kozlowski
ab7cc66dfa clk: samsung: exynos4415: Constify all clock initializers
All of initialization data can be made const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:03 +02:00
Krzysztof Kozlowski
d0e4ca5695 clk: samsung: exynos4: Constify all clock initializers
All of initialization data can be made const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:02 +02:00
Krzysztof Kozlowski
8f3ac36de1 clk: samsung: exynos4: Move local function to init section
The local exynos4_get_xom() function is referenced only from other
init-level functions.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:02 +02:00
Krzysztof Kozlowski
0a7d82e6ee clk: samsung: exynos3250: Constify all clock initializers
All of initialization data can be made const.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:01 +02:00
Krzysztof Kozlowski
b3a96eed8e clk: samsung: exynos3250: Move platform driver and of_device_id to init section
The platform_driver and of_device_id structs can be moved to init
section because they are referenced only from subsys_initcall-level
function.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:18:00 +02:00
Krzysztof Kozlowski
9f92c0bace clk: samsung: Constify clock init data with clock arrays
samsung_cmu_register_one() can accept pointer to const initialization
data: struct samsung_cmu_info. The members of the latter can also be
pointers to const data.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:17:59 +02:00
Krzysztof Kozlowski
d8137e035f clk: samsung: clkout: Add support for Exynos5410
Add compatible for Exynos5410 so the PMU on this SoC would provide
CLKOUT.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:17:58 +02:00
Krzysztof Kozlowski
dfb86ade53 clk: samsung: Remove useless check for return value of samsung_clk_init
The samsung_clk_init() cannot return NULL. Either it returns allocated
memory or it panics.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:17:57 +02:00
Alim Akhtar
9da752f0e3 clk: samsung: exynos7: Don't gate CMU_{CCORE, FSYS0} blocks clock
This patch adds CLK_IS_CRITICAL flag to ACLK_CCORE_133 and ACLK_FSYS0_200
clocks. These clocks are critical for accessing CMU_CCORE and CMU_FSYS0
blocks registers. Let these clocks to be enabled all the time.

Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:17:56 +02:00
Krzysztof Kozlowski
4528dd8ed4 dt-bindings: clock: Add watchdog and SSS clock IDs to Exynos5410
Add IDs for watchdog and Security SubSystem to Exynos5410.  Use the same
number as for Exynos5420 just in case in future these drivers were
merged.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-02 11:17:55 +02:00
Krzysztof Kozlowski
109869f522 dt-bindings: clock: Add TMU clock ID to Exynos5410
Add ID for TMU clock to Exynos5410. Use the same number as for
Exynos5420 just in case in future these drivers were merged.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-06-01 11:38:56 +02:00
Krzysztof Kozlowski
ed1e1505db dt-bindings: clock: Add I2C, HSI2C and RTC clock IDs to Exynos5410
Add IDs for I2C, USI (HSI2C) and RTC clocks to Exynos5410. Use the same
number as for Exynos5420 just in case in future these drivers are merged.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-05-30 16:00:11 +02:00
Krzysztof Kozlowski
5cd3535a27 dt-bindings: clock: Add PWM and USB clock IDs to Exynos5410
Add IDs for PWM and USB clocks to Exynos5410. Use the same number as for
Exynos5420 just in case in future these drivers were merged.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-05-30 16:00:02 +02:00
Krzysztof Kozlowski
4c5773f9f5 dt-bindings: clock: Add license and reformat Exynos5410 clock IDs
Add license and copyrights (file introduced in 2014) to header with
Exynos5410 clock IDs. Additionally reformat it to improve readability.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
2016-05-30 15:59:06 +02:00
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: fcfd2fbf22d2 ("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: fcfd2fbf22d2 ("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 c8f33d0bec99 ("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: c8f33d0bec99 ("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 ce657611baf9 ("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: ce657611baf9 ("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: 5d22fc25d4fc ("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 689de1d6ca95 ("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 0fed3ac866ea ("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