Commit Graph

601714 Commits

Author SHA1 Message Date
Masahiro Yamada aa543888ca pinctrl: uniphier: support per-pin input enable for new SoCs
Upcoming new pinctrl drivers for PH1-LD11 and PH-LD20 support input
signal gating for each pin.  (While, existing ones only support it
per pin-group.)  This commit updates the core part for that.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 12:49:48 +02:00
Masahiro Yamada c2ebf4754b pinctrl: uniphier: introduce capability flag
The core part of the UniPhier pinctrl driver needs to support a new
capability for upcoming UniPhier ARMv8 SoCs.  This sometimes happens
because pinctrl drivers include really SoC-specific stuff.

This commit intends to tidy up SoC-specific parameters of the existing
drivers before adding the new one.  Having just one flag would be
better than adding a new struct member every time a new SoC-specific
capability comes up.

At this time, there is one flag, UNIPHIER_PINCTRL_CAPS_DBGMUX_SEPARATE.
This capability (I'd say rather quirk) was added for PH1-Pro4 and
PH1-Pro5 as requirement from a customer.  For those SoCs, one pin-mux
setting is controlled by the combination of two separate registers; the
LSB bits at register offset (8 * N) and the MSB bits at (8 * N + 4).
Because it is impossible to update two separate registers atomically,
the LOAD_PINCTRL register should be set in order to make the pin-mux
settings really effective.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 12:48:28 +02:00
Masahiro Yamada 94bf176b97 pinctrl: uniphier: support pin configuration in sparse pin space
Unfortunately, the pin number of the new SoC, PH1-LD11, is not
contiguous.  The base frame work must be adjusted to support the new
SoC pinctrl driver.  The pin_desc_get() exploits radix-tree for pin
look-up, so it works more efficiently with sparse pin space.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 12:47:18 +02:00
Masahiro Yamada 72e5706aa7 pinctrl: uniphier: support 3-bit drive strength control
The new ARMv8 SoC, PH1-LD20, supports more fine-grained drive
strength control.  Drive strength of some pins are controlled by
3-bit width registers (8-level granularity).

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 12:46:18 +02:00
Masahiro Yamada 9eaa98a63c pinctrl: uniphier: rename macros for drive strength control
The new ARMv8 SoC, PH1-LD20, supports more fine-grained drive
strength control.  Some of the configuration registers on it have
3-bit width.

The feature will be supported in the next commit, but a problem is
that macro names are getting longer and longer in the current naming
scheme.

Before moving forward, this commit renames macros as follows:

  UNIPHIER_PIN_DRV_4_8        -> UNIPHIER_PIN_DRV_1BIT
  UNIPHIER_PIN_DRV_8_12_16_20 -> UNIPHIER_PIN_DRV_2BIT
  UNIPHIER_PIN_DRV_FIXED_4    -> UNIPHIER_PIN_DRV_FIXED4
  UNIPHIER_PIN_DRV_FIXED_5    -> UNIPHIER_PIN_DRV_FIXED5
  UNIPHIER_PIN_DRV_FIXED_8    -> UNIPHIER_PIN_DRV_FIXED8

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 12:42:04 +02:00
Masahiro Yamada fc78a56631 pinctrl: uniphier: allocate struct pinctrl_desc in probe function
Currently, every SoC driver defines struct pinctrl_desc statically,
i.e. it consumes memory footprint even if it is not probed.

In multi-platform, many pinctrl drivers are linked (generally as
built-in objects), although only one of them is actually used.
So, it is reasonable to allocate memory dynamically where possible.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 12:40:38 +02:00
Masahiro Yamada 4109508a85 pinctrl: uniphier: set pinctrl_desc name in common probe function
Every SoC driver sets the same name for struct pinctrl_desc and
platform_driver.  The common probe function can set desc->name
instead of duplicating strings in each SoC driver.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 12:39:31 +02:00
Masahiro Yamada 7d36b2451a pinctrl: uniphier: set pinctrl_desc owner in common probe function
The owner of the struct pinctrl_desc matches that of platform_driver.
Set it in the common probe function.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 12:38:30 +02:00
Masahiro Yamada 4725774f59 pinctrl: uniphier: fix register offsets for drive strength control
These pin tables were generated by parsing hardware documents with
a script, but the script had a bug.  Fix the register offsets.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 12:37:34 +02:00
Masahiro Yamada a4c6052bc1 pinctrl: uniphier: rename function and variable names
Make function/variable names match the file names for consistency.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 12:36:12 +02:00
Masahiro Yamada 10ef8277ec pinctrl: uniphier: fix .pin_dbg_show() callback
Without this, reading the "pins" in the debugfs causes kernel BUG.

Fixes: 6e90889202 ("pinctrl: UniPhier: add UniPhier pinctrl core support")
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:56:16 +02:00
Peng Fan 6e408ed8be pinctrl: imx: fix initialization of imx_pinctrl_desc
To i.MX7D, there are two iomux controllers, iomuxc and iomuxc_lpsr.
They should not share one pin controller descriptor, otherwise
the value filled into imx_pinctrl_desc when probing the first
iomux controller will be overridden when probing the second one.

In this patch, discard the static allcoated imx_pinctrl_desc and
switch to dynamically allcate pin controller descriptor for each
iomux controller.

Signed-off-by: Peng Fan <van.freenix@gmail.com>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Cc: Stefan Agner <stefan@agner.ch>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:54:31 +02:00
Kevin Hilman a454c67d1f pinctrl: amlogic: gxbb: add ethernet pins
Add EE domain pins for ethernet interface.

Acked-by: Carlo Caione <carlo@endlessm.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:37:09 +02:00
Kevin Hilman 6db0f3a8a0 pinctrl: amlogic: gxbb: add more UART pins
Add EE domain pins for UART A, B & C.

Acked-by: Carlo Caione <carlo@endlessm.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:36:17 +02:00
Kevin Hilman 93ed09e6b6 pinctrl: amlogic: gxbb: add EMMC and SD pins
Add EE domain pins for eMMC and SD card.

Acked-by: Carlo Caione <carlo@endlessm.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:35:25 +02:00
Kevin Hilman a7db188943 pinctrl: amlogic: gxbb: add UART_AO_B, I2C
Add pins for some more AO domain devices: UART_AO_B and I2C master &
slave.

Acked-by: Carlo Caione <carlo@endlessm.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:34:36 +02:00
Masahiro Yamada 1fb1f0540d pinctrl: return -ENOMEM instead of -EINVAL for kasprintf() failure
-ENOMEM is more suitable error code because kasprintf() fails
in case of memory shortage.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:33:00 +02:00
Masahiro Yamada 8b2b3dcb34 pinctrl: digicolor: add missing platform_set_drvdata() call
gc_pinctrl_remove() calls platform_get_drvdata(), but I see neither
platform_set_drvdata() nor dev_set_drvdata() anywhere in this driver.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:30:38 +02:00
Masahiro Yamada a672eb5e27 pinctrl: pinconf: separate config parameters with commas for debugfs
To improve debugfs readability, use commas instead of whitespaces
for separating configuration parameters.

For example, the "pinconf-pins" dump on my board will change as follows:

Without this commit:

 # head -5 pinconf-pins
 Pin config settings per pin
 Format: pin (name): configs
 pin 0 (ED0): input bias pull down output drive strength (8 mA) input enabled
 pin 1 (ED1): input bias pull down output drive strength (8 mA) input enabled
 pin 2 (ED2): input bias pull down output drive strength (8 mA) input enabled

With this commit:

 # head -5 pinconf-pins
 Pin config settings per pin
 Format: pin (name): configs
 pin 0 (ED0): input bias pull down, output drive strength (8 mA), input enabled
 pin 1 (ED1): input bias pull down, output drive strength (8 mA), input enabled
 pin 2 (ED2): input bias pull down, output drive strength (8 mA), input enabled

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:29:06 +02:00
Masahiro Yamada cd8f61f1e5 pinctrl: copy per-pin driver private data to struct pin_desc
Currently, struct pinctrl_pin_desc can have per-pin driver private
data, but it is not copied to struct pin_desc.

For a driver with sparse pin space, for-loop search like below would
be necessary in order to get the driver-specific data for a desired
pin number.

  for (i = 0; i < pctldev->desc->npins; i++)
          if (pin_number == pctldev->desc->pins[i].number)
                  return pctldev->desc->pins[i].drv_data;

This is not efficient for a driver with a large number of pins.
So, copy the data to struct pin_desc when each pin is registered
for the faster radix tree lookup.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:27:19 +02:00
Masahiro Yamada cf9d994dcf pinctrl: do not care about blank pin name
If a pin name is not specified in struct pinctrl_pin_desc,
pinctrl_register_one_pin() dynamically assigns its name.
So, desc->name is always a valid pointer here.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:19:56 +02:00
Patrice Chotard 4fac724fd7 pinctrl: stm32: factorize stm32_pconf_input/output_get()
As these 2 functions code are 95% similar, factorize them.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-31 10:06:12 +02:00
Krzysztof Kozlowski a0ee2ac039 pinctrl: samsung: Suppress unbinding to prevent theoretical attacks
Although unbinding a pinctrl driver requires root privileges but it
still might be used theoretically in certain attacks (by triggering NULL
pointer exception or memory corruption).

Samsung pincontrol drivers are essential for system operation so their
removal is not expected. They do not implement remove() driver callback
and they are not buildable as modules.

Suppression of the unbinding will prevent triggering NULL pointer
exception like this (Odroid XU3):

  $ echo 13400000.pinctrl > /sys/bus/platform/drivers/samsung-pinctrl/unbind
  $ cat /sys/kernel/debug/gpio

  Unable to handle kernel NULL pointer dereference at virtual address 00000c44
  pgd = ec41c000
  [00000c44] *pgd=6d448835, *pte=00000000, *ppte=00000000
  Internal error: Oops: 17 [#1] PREEMPT SMP ARM
    (samsung_gpio_get) from [<c034f9a0>] (gpiolib_seq_show+0x1b0/0x26c)
    (gpiolib_seq_show) from [<c01fb8c0>] (seq_read+0x304/0x4b8)
    (seq_read) from [<c02dbc78>] (full_proxy_read+0x4c/0x64)
    (full_proxy_read) from [<c01d9fb0>] (__vfs_read+0x2c/0x110)
    (__vfs_read) from [<c01db400>] (vfs_read+0x8c/0x110)
    (vfs_read) from [<c01db4c4>] (SyS_read+0x40/0x8c)
    (SyS_read) from [<c01078c0>] (ret_fast_syscall+0x0/0x3c)

Suggested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30 09:41:49 +02:00
Neil Armstrong 2f94ced704 pinctrl: oxnas: Add GPIO get_direction
Implement a get_direction callback for the OXNAS GPIO driver in order
to have pin output polarity in debugfs and new userspace ABI.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30 09:41:48 +02:00
Laxman Dewangan 2df723d49c pinctrl: max77620: add pincontrol driver for MAX77620/MAX20024
MAXIM Semiconductor's PMIC, MAX77620/MAX20024 has 8 GPIO pins
which also act as the special function in alternate mode. Also
there is configuration like push-pull, open drain, FPS timing
etc for these pins.

Add pin control driver to configure these parameters through
pin control APIs.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30 09:41:47 +02:00
Laxman Dewangan 7916c0c3c6 pinctrl: add DT binding doc for pincontrol of PMIC max77620/max20024
Maxim Semiconductor's PMIC MAX77620/MAX20024 has 8 GPIO pins
which act as GPIO as well as special function mode.

Add DT binding document to configure pins in function mode as
well as pin configuration parameters.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30 09:41:46 +02:00
Laxman Dewangan b47fca5148 pinctrl: tegra: Get rid of parked_reg
Remove the use of parked_reg and use parked_bit for to know
whether field is supported or not.

This is fix for the patch
commit 1d18a3f0f0
"pinctrl: tegra: avoid parked_reg and parked_bank

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30 09:41:46 +02:00
Linus Walleij 0bde4897d3 Revert "Revert "pinctrl: tegra: avoid parked_reg and parked_bank""
This reverts commit 0d5358330c.
2016-05-30 09:41:45 +02:00
Neil Armstrong aeb99c85c1 dt-bindings: Add Oxford Semiconductor OXNAS pinctrl and gpio bindings
Add pinctrl and gpio DT bindings for Oxford Semiconductor OXNAS SoC Family.
This version supports the ARM926EJ-S based OX810SE SoC with 34 IO pins.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30 09:41:45 +02:00
Neil Armstrong 611dac1e48 pinctrl: Add Oxford Semiconductor OXNAS pinctrl and gpio driver
Add pinctrl and gpio control support to Oxford Semiconductor OXNAS SoC Family.
This version supports the ARM926EJ-S based OX810SE SoC with 34 IO pins.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-30 09:41:45 +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: 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
Linus Torvalds 4e8440b3b6 Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fix from Wolfram Sang:
 "A fix for a regression introduced yesterday.

  The regression didn't show up here locally because I did not have
  PAGE_POISONING enabled.  And buildbots discovered this only after it
  hit your tree.  Thanks to Dan for the quick response"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: dev: use after free in detach
2016-05-28 12:38:50 -07:00