Use platform_data to pass musb configuration-specific
details to musb driver.
This patch will prevent that other platforms selecting
HAVE_CLK and enabling musb won't break tree building.
The other parts of it will come when linux-omap merge
up more omap2/3 board-files.
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch removes the commented out line for the not available
CONFIG_SA1100_USB option.
Reported-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
include/linux/i2c-pnx.h was missed when moving the include files.
Fix it now; it doesn't really need to include mach/i2c.h at all.
Successfully build tested with pnx4008_defconfig, which had
failed in linux-next.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The existing code tries to get the pmd for the temporary page table
by doing:
pgd = pgd_alloc(&init_mm);
pmd = pmd_offset(pgd, PHYS_OFFSET);
Since we have a two level page table, pmd_offset() is a no-op, so
this just has a casting effect from a pgd to a pmd - the address
argument is unused. So this can't work.
Normally, we'd do:
pgd = pgd_offset(&init_mm, PHYS_OFFSET);
...
pmd = pmd_offset(pgd, PHYS_OFFSET);
to get the pmd you want. However, pgd_offset() takes the mm_struct,
not the (unattached) pgd we just allocated. So, instead use:
pgd = pgd_alloc(&init_mm);
pmd = pmd_offset(pgd + pgd_index(PHYS_OFFSET), PHYS_OFFSET);
Reported-by: Antti P Miettinen <ananaza@iki.fi>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Change num_chipselect for lubbock ssp master to reflect requirement
of spi subsystem that all buses have at least 1 chip select.
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Acked-by: Eric Miao <eric.miao@marvell.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Remove includes of asm/hardware.h in addition to asm/arch/hardware.h.
Then, since asm/hardware.h only exists to include asm/arch/hardware.h,
update everything to directly include asm/arch/hardware.h and remove
asm/hardware.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There are 43 includes of asm/mach-types.h by files that don't
reference anything from that file. Remove these unnecessary
includes.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Due to the problem of reset status bits being handled by different
registers between pxa2xx and pxa3xx, introduce a global reset_status
variable, initialized by SoC-specific code and later being used by
other drivers.
And also introduce clear_reset_status(), which is used to clear the
corresponding status bits. Pass RESET_STATUS_ALL to clear all bits.
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Compiling pcm990 produces an error:
In file included from arch/arm/mach-pxa/pcm990-baseboard.c:25:
include/linux/ide.h:645: error: 'CONFIG_IDE_MAX_HWIFS' undeclared here (not in a function)
Fix it by removing unneeded header include.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
No file should be explicitly referencing its own platform headers
by specifying an absolute include path. Fix these paths to use
standard <asm/arch/...> includes.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move platform independent header files to arch/arm/include/asm, leaving
those in asm/arch* and asm/plat* alone.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (46 commits)
tcp: MD5: Fix IPv6 signatures
skbuff: add missing kernel-doc for do_not_encrypt
net/ipv4/route.c: fix build error
tcp: MD5: Fix MD5 signatures on certain ACK packets
ipv6: Fix ip6_xmit to send fragments if ipfragok is true
ipvs: Move userspace definitions to include/linux/ip_vs.h
netdev: Fix lockdep warnings in multiqueue configurations.
netfilter: xt_hashlimit: fix race between htable_destroy and htable_gc
netfilter: ipt_recent: fix race between recent_mt_destroy and proc manipulations
netfilter: nf_conntrack_tcp: decrease timeouts while data in unacknowledged
irda: replace __FUNCTION__ with __func__
nsc-ircc: default to dongle type 9 on IBM hardware
bluetooth: add quirks for a few hci_usb devices
hysdn: remove the packed attribute from PofTimStamp_tag
isdn: use the common ascii hex helpers
tg3: adapt tg3 to use reworked PCI PM code
atm: fix direct casts of pointers to u32 in the InterPhase driver
atm: fix const assignment/discard warnings in the ATM networking driver
net: use the common ascii hex helpers
random32: seeding improvement
...
* git://git.infradead.org/mtd-2.6:
[MTD] [NAND] drivers/mtd/nand/nandsim.c: fix printk warnings
[MTD] [NAND] Blackfin NFC Driver: Cleanup the error exit path of bf5xx_nand_probe function
[MTD] [NAND] Blackfin NFC Driver: use standard dev_err() rather than printk()
[MTD] [NAND] Blackfin NFC Driver: enable Blackfin nand HWECC support by default
[MTD] [NAND] Blackfin NFC Driver: add proper devinit/devexit markings to probe/remove functions
[MTD] [NAND] Blackfin NFC Driver: add support for the ECC layout the Blackfin bootrom uses
[MTD] [NAND] Blackfin NFC Driver: fix bug - hw ecc calc by making sure we extract 11 bits from each register instead of 10
[MTD] [NAND] Blackfin NFC Driver: fix bug - do not clobber the status from the first 256 bytes if operating on 512 pages
[MTD] [NAND] diskonchip.c fix sparse endian warnings
[MTD] [NAND] drivers/mtd/nand/nandsim.c needs div64.h
[JFFS2] Fix allocation of summary buffer
Fix rename of at91_nand -> atmel_nand
[MTD] [NOR] drivers/mtd/chips/jedec_probe.c: fix Am29DL800BB device ID
[MTD] MTD_DEBUG always does compile-time typechecks
[MTD] DataFlash: bugfix, binary page sizes now handled
[MTD] [NAND] fsl_elbc_nand.c: fix printk warning
[MTD] [NAND] nandsim: support random page read command
[MTD] [NAND] fix subpage read for small page NAND
Structs called at91_nand_data where renamed to atmel_nand_data
and configs called *MTD_NAND_AT91* where renamed to
*MTD_NAND_ATMEL*. This was unfortunately not done consistently,
causing NAND chips not being initialised on several ARM boards.
I am aware that the author of the original change did not rename
MTD_NAND_AT91_BUSWIDTH to MTD_NAND_ATMEL_BUSWIDTH, for example.
All *MTD_NAND_AT91* where renamed to *MTD_NAND_ATMEL* in order
to keep naming consistency.
This patch was only tested on a MACH_SAM9_L9260, as this is the
only ARM board I have to my disposal.
Before this patch:
$ git-ls-files |xargs grep atmel_nand |wc -l
105
$ git-ls-files |xargs grep at91_nand |wc -l
4
$ git-ls-files |xargs grep MTD_NAND_ATMEL |wc -l
8
$ git-ls-files |xargs grep MTD_NAND_AT91 |wc -l
47
After this patch:
$ git-ls-files |xargs grep atmel_nand |wc -l
109
$ git-ls-files |xargs grep at91_nand |wc -l
0
$ git-ls-files |xargs grep MTD_NAND_ATMEL |wc -l
55
$ git-ls-files |xargs grep MTD_NAND_AT91 |wc -l
0
Signed-off-by: Pieter du Preez <pdupreez@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Claim the initrd memory exclusively, and order other memory
reservations beforehand. This allows us to determine whether
the initrd memory was overwritten, and disable the initrd in
that case.
This avoids a 'bad page state' bug.
Tested-by: Ralph Siemsen <ralphs@netwinder.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds kernel build support for the regulator core.
Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Liam Girdwood <lg@opensource.wolfsonmicro.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (21 commits)
x86/PCI: use dev_printk when possible
PCI: add D3 power state avoidance quirk
PCI: fix bogus "'device' may be used uninitialized" warning in pci_slot
PCI: add an option to allow ASPM enabled forcibly
PCI: disable ASPM on pre-1.1 PCIe devices
PCI: disable ASPM per ACPI FADT setting
PCI MSI: Don't disable MSIs if the mask bit isn't supported
PCI: handle 64-bit resources better on 32-bit machines
PCI: rewrite PCI BAR reading code
PCI: document pci_target_state
PCI hotplug: fix typo in pcie hotplug output
x86 gart: replace to_pages macro with iommu_num_pages
x86, AMD IOMMU: replace to_pages macro with iommu_num_pages
iommu: add iommu_num_pages helper function
dma-coherent: add documentation to new interfaces
Cris: convert to using generic dma-coherent mem allocator
Sh: use generic per-device coherent dma allocator
ARM: support generic per-device coherent dma mem
Generic dma-coherent: fix DMA_MEMORY_EXCLUSIVE
x86: use generic per-device dma coherent allocator
...
This fixes a merge goof whereby ARCH_EP93XX got the "select HAVE_CLK" line
which belongs instead with ARCH_AT91.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(20072fd0c9 lost most of its changes
somehow, came from a mbox archive applied with git-am. No idea
what happened. This puts back the missing bits. --rmk)
The initial patch from Lothar, and Lennert make it into a cleaner
one, modified and tested on PXA320 by Eric Miao.
This patch moves the L2 cache operations out of proc-xsc3.S into
dedicated outer cache support code.
CACHE_XSC3L2 can be deselected so no L2 cache specific code will be
linked in, and that L2 enable bit will not be set, this applies to
the following cases:
a. _only_ PXA300/PXA310 support included and no L2 cache wanted
b. PXA320 support included, but want L2 be disabled
So the enabling of L2 depends on two things:
- CACHE_XSC3L2 is selected
- and L2 cache is present
Where the latter is only a safeguard (previous testing shows it works
OK even when this bit is turned on).
IXP series of processors with XScale3 cannot disable L2 cache for the
moment since they depend on the L2 cache for its coherent memory, so
IXP may always select CACHE_XSC3L2.
Other L2 relevant bits are always turned on (i.e. the original code
enclosed by #if L2_CACHE_ENABLED .. #endif), as they showed no side
effects. Specifically, these bits are:
- OC bits in TTBASE register (table walk outer cache attributes)
- LLR Outer Cache Attributes (OC) in Auxiliary Control Register
Signed-off-by: Lothar WaÃ<9f>mann <LW@KARO-electronics.de>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
struct at91_nand has been renamed atmel_nand. Fix the four boards that
were added since the patch was created.
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: Andrew Victor <linux@maxim.org.za>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Remove not needed export and fix warning:
WARNING: vmlinux.o(__ksymtab+0x400): Section mismatch in reference from the variable __ksymtab_set_imx_fb_info to the function .init.text:set_imx_fb_info()
The symbol set_imx_fb_info is exported and annotated __init
Fix this by removing the __init annotation of set_imx_fb_info or drop the export.
Signed-off-by: Paulius Zaleckas <paulius.zaleckas@teltonika.lt>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
It seems this small label was lost in the last merge. Without it
no CPU type is selected for the MX2 family of processors. And a build
will fail badly...
Signed-off-by: Juergen Beisert <j.beisert@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
The shared mmap code works fine for the test case, which only checked
for two shared maps of the same file. However, three shared maps
result in one mapping remaining cached, resulting in stale data being
visible via that mapping. Fix this.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
IRQT_* and __IRQT_* were obsoleted long ago by patch [3692/1].
Remove them completely. Sed script for the reference:
s/__IRQT_RISEDGE/IRQ_TYPE_EDGE_RISING/g
s/__IRQT_FALEDGE/IRQ_TYPE_EDGE_FALLING/g
s/__IRQT_LOWLVL/IRQ_TYPE_LEVEL_LOW/g
s/__IRQT_HIGHLVL/IRQ_TYPE_LEVEL_HIGH/g
s/IRQT_RISING/IRQ_TYPE_EDGE_RISING/g
s/IRQT_FALLING/IRQ_TYPE_EDGE_FALLING/g
s/IRQT_BOTHEDGE/IRQ_TYPE_EDGE_BOTH/g
s/IRQT_LOW/IRQ_TYPE_LEVEL_LOW/g
s/IRQT_HIGH/IRQ_TYPE_LEVEL_HIGH/g
s/IRQT_PROBE/IRQ_TYPE_PROBE/g
s/IRQT_NOEDGE/IRQ_TYPE_NONE/g
Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* git://git.infradead.org/mtd-2.6: (57 commits)
[MTD] [NAND] subpage read feature as a way to increase performance.
CPUFREQ: S3C24XX NAND driver frequency scaling support.
[MTD][NAND] au1550nd: remove unused variable
[MTD] jedec_probe: Fix SST 16-bit chip detection
[MTD][MTDPART] Fix a division by zero bug
[MTD][MTDPART] Cleanup and document the erase region handling
[MTD][MTDPART] Handle most checkpatch findings
[MTD][MTDPART] Seperate main loop from per-partition code in add_mtd_partition
[MTD] physmap: resume already suspended chips on failure to suspend
[MTD] physmap: Fix suspend/resume/shutdown bugs.
[MTD] [NOR] Fix -ETIMEO errors in CFI driver
[MTD] [NAND] fsl_elbc_nand: fix section mismatch with CONFIG_MTD_OF_PARTS=y
[JFFS2] Use .unlocked_ioctl
[MTD] Fix const assignment in the MTD command line partitioning driver
[MTD] [NOR] gen_probe: No debug message when debugging is disabled
[MTD] [NAND] remove __PPC__ hardcoded address from DiskOnChip drivers
[MTD] [MAPS] Remove the bast-flash driver.
[MTD] [NAND] fsl_elbc_nand: ecclayout cleanups
[MTD] [NAND] fsl_elbc_nand: implement support for flash-based BBT
[MTD] [NAND] fsl_elbc_nand: fix OOB workability for large page NAND chips
...
Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres. Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.
Non-trivial places are:
arch/powerpc/mm/init_64.c
arch/powerpc/mm/hugetlbpage.c
This is flag day, yes.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Jon Tollefson <kniht@linux.vnet.ibm.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Matt Mackall <mpm@selenic.com>
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER
architecture does:
This enables us to cleanly fix the Calgary IOMMU issue that some devices
are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423).
I think that per-device dma_mapping_ops support would be also helpful for
KVM people to support PCI passthrough but Andi thinks that this makes it
difficult to support the PCI passthrough (see the above thread). So I
CC'ed this to KVM camp. Comments are appreciated.
A pointer to dma_mapping_ops to struct dev_archdata is added. If the
pointer is non NULL, DMA operations in asm/dma-mapping.h use it. If it's
NULL, the system-wide dma_ops pointer is used as before.
If it's useful for KVM people, I plan to implement a mechanism to register
a hook called when a new pci (or dma capable) device is created (it works
with hot plugging). It enables IOMMUs to set up an appropriate
dma_mapping_ops per device.
The major obstacle is that dma_mapping_error doesn't take a pointer to the
device unlike other DMA operations. So x86 can't have dma_mapping_ops per
device. Note all the POWER IOMMUs use the same dma_mapping_error function
so this is not a problem for POWER but x86 IOMMUs use different
dma_mapping_error functions.
The first patch adds the device argument to dma_mapping_error. The patch
is trivial but large since it touches lots of drivers and dma-mapping.h in
all the architecture.
This patch:
dma_mapping_error() doesn't take a pointer to the device unlike other DMA
operations. So we can't have dma_mapping_ops per device.
Note that POWER already has dma_mapping_ops per device but all the POWER
IOMMUs use the same dma_mapping_error function. x86 IOMMUs use device
argument.
[akpm@linux-foundation.org: fix sge]
[akpm@linux-foundation.org: fix svc_rdma]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix bnx2x]
[akpm@linux-foundation.org: fix s2io]
[akpm@linux-foundation.org: fix pasemi_mac]
[akpm@linux-foundation.org: fix sdhci]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: fix sparc]
[akpm@linux-foundation.org: fix ibmvscsi]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Avi Kivity <avi@qumranet.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
7444a72eff caused these platforms to lose
their GPIOLIB configuration. Convert the missed Kconfig symbols using:
sed -i s/HAVE_GPIO_LIB/ARCH_REQUIRE_GPIOLIB/ arch/arm/Kconfig arch/arm/plat-s3c24xx/Kconfig
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Xose Vazquez Perez points out that this file should not be marked
executable.
Reported-by: Xose Vazquez Perez <xose.vazquez@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch fixes a typo introduced by
commit f37f46eb1c
([ARM] nommu: add ARM946E-S core support).
Reported-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
This patch adds functionality to the gpio-lib subsystem to make it
possible to enable the gpio-lib code even if the architecture code didn't
request to get it built in.
The archtitecture code does still need to implement the gpiolib accessor
functions in its asm/gpio.h file. This patch adds the implementations for
x86 and PPC.
With these changes it is possible to run generic GPIO expansion cards on
every architecture that implements the trivial wrapper functions. Support
for more architectures can easily be added.
Signed-off-by: Michael Buesch <mb@bu3sch.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Brownell <david-b@pacbell.net>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Samuel Ortiz <sameo@openedhand.com>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This adds a simple sysfs interface for GPIOs.
/sys/class/gpio
/export ... asks the kernel to export a GPIO to userspace
/unexport ... to return a GPIO to the kernel
/gpioN ... for each exported GPIO #N
/value ... always readable, writes fail for input GPIOs
/direction ... r/w as: in, out (default low); write high, low
/gpiochipN ... for each gpiochip; #N is its first GPIO
/base ... (r/o) same as N
/label ... (r/o) descriptive, not necessarily unique
/ngpio ... (r/o) number of GPIOs; numbered N .. N+(ngpio - 1)
GPIOs claimed by kernel code may be exported by its owner using a new
gpio_export() call, which should be most useful for driver debugging.
Such exports may optionally be done without a "direction" attribute.
Userspace may ask to take over a GPIO by writing to a sysfs control file,
helping to cope with incomplete board support or other "one-off"
requirements that don't merit full kernel support:
echo 23 > /sys/class/gpio/export
... will gpio_request(23, "sysfs") and gpio_export(23);
use /sys/class/gpio/gpio-23/direction to (re)configure it,
when that GPIO can be used as both input and output.
echo 23 > /sys/class/gpio/unexport
... will gpio_free(23), when it was exported as above
The extra D-space footprint is a few hundred bytes, except for the sysfs
resources associated with each exported GPIO. The additional I-space
footprint is about two thirds of the current size of gpiolib (!). Since
no /dev node creation is involved, no "udev" support is needed.
Related changes:
* This adds a device pointer to "struct gpio_chip". When GPIO
providers initialize that, sysfs gpio class devices become children of
that device instead of being "virtual" devices.
* The (few) gpio_chip providers which have such a device node have
been updated.
* Some gpio_chip drivers also needed to update their module "owner"
field ... for which missing kerneldoc was added.
* Some gpio_chips don't support input GPIOs. Those GPIOs are now
flagged appropriately when the chip is registered.
Based on previous patches, and discussion both on and off LKML.
A Documentation/ABI/testing/sysfs-gpio update is ready to submit once this
merges to mainline.
[akpm@linux-foundation.org: a few maintenance build fixes]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Cc: Greg KH <greg@kroah.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently list of kretprobe instances are stored in kretprobe object (as
used_instances,free_instances) and in kretprobe hash table. We have one
global kretprobe lock to serialise the access to these lists. This causes
only one kretprobe handler to execute at a time. Hence affects system
performance, particularly on SMP systems and when return probe is set on
lot of functions (like on all systemcalls).
Solution proposed here gives fine-grain locks that performs better on SMP
system compared to present kretprobe implementation.
Solution:
1) Instead of having one global lock to protect kretprobe instances
present in kretprobe object and kretprobe hash table. We will have
two locks, one lock for protecting kretprobe hash table and another
lock for kretporbe object.
2) We hold lock present in kretprobe object while we modify kretprobe
instance in kretprobe object and we hold per-hash-list lock while
modifying kretprobe instances present in that hash list. To prevent
deadlock, we never grab a per-hash-list lock while holding a kretprobe
lock.
3) We can remove used_instances from struct kretprobe, as we can
track used instances of kretprobe instances using kretprobe hash
table.
Time duration for kernel compilation ("make -j 8") on a 8-way ppc64 system
with return probes set on all systemcalls looks like this.
cacheline non-cacheline Un-patched kernel
aligned patch aligned patch
===============================================================================
real 9m46.784s 9m54.412s 10m2.450s
user 40m5.715s 40m7.142s 40m4.273s
sys 2m57.754s 2m58.583s 3m17.430s
===========================================================
Time duration for kernel compilation ("make -j 8) on the same system, when
kernel is not probed.
=========================
real 9m26.389s
user 40m8.775s
sys 2m7.283s
=========================
Signed-off-by: Srinivasa DS <srinivasa@in.ibm.com>
Signed-off-by: Jim Keniston <jkenisto@us.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Masami Hiramatsu <mhiramat@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
