Fixes build errors caused by the:
- OF device_node pointer being moved into struct device
- removal of the match_table field from struct of_platform_driver
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
CC: Paul Gortmaker <p_gortmaker@yahoo.com>
CC: Alessandro Zummo <a.zummo@towertech.it>
CC: Wolfgang Denk <wd@denx.de>
CC: Tejun Heo <tj@kernel.org>
CC: Anatolij Gustschin <agust@denx.de>
CC: rtc-linux@googlegroups.com
CC: devicetree-discuss@lists.ozlabs.org
Fixes build errors caused by the:
- OF device_node pointer being moved into struct device
- removal of the match_table field from struct of_platform_driver
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Fixes build errors caused by the:
- OF device_node pointer being moved into struct device
- removal of the match_table field from struct of_platform_driver
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Fixes build errors caused by the:
- OF device_node pointer being moved into struct device
- removal of the match_table field from struct of_platform_driver
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
commit 61c7a080a5 ( of: Always use
'struct device.of_node' to get device node pointer.) missed
drivers/watchdog/mpc8xxx_wdt.c. This patch fixes it
Signed-off-by: Michael Guntsche <mike@it-loops.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
This patch fixes a build error caused by the OF device_node pointer
being moved into struct device.
Fixes bug introduced by commit 61c7a080a5
(of: Always use 'struct device.of_node' to get device node pointer)
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
CC: Sean MacLennan <smaclennan@pikatech.com>
CC: spi-devel-general@lists.sourceforge.net
CC: devicetree-discuss@lists.ozlabs.org
Fix driver to use new location of of_node pointer (introduced by commit
use new location of of_node pointer (introduced by commit
61c7a080a5a061c976988fd4b844dfb468dda255; of: Always use 'struct
device.of_node' to get device node pointer)
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Reported-by: John Linn <john.linn@xilinx.com>
CC: Greg Kroah-Hartman <gregkh@suse.de>
CC: Alan Stern <stern@rowland.harvard.edu>
CC: linux-usb@vger.kernel.org
CC: devicetree-discuss@lists.ozlabs.org
Implement ata_scsi_unlock_native_capacity() which will be called
through SCSI layer when block layer notices that partitions on a
device extend beyond the end of the device. It requests EH to unlock
HPA, waits for completion and returns the current device capacity.
This allows libata to unlock HPA on demand instead of having to decide
whether to unlock upfront. Unlocking on demand is safer than
unlocking by upfront because some BIOSes write private data to the
area beyond HPA limit. This was suggested by Ben Hutchings.
Signed-off-by: Tejun Heo <tj@kernel.org>
Suggested-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
After late HPA unlock, libata kept using the original capacity
ignoring the new larger native capacity. Enlarging device on the fly
doesn't cause any harm. Use the larger native capacity instead. This
will enable on-demand HPA unlocking.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Implement sd_unlock_native_capacity() method which calls into
hostt->unlock_native_capacity() if implemented. This will be invoked
by block layer if partitions extend beyond the end of the device and
can be used to implement, for example, on-demand ATA host protected
area unlocking.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
On mcp55, nIEN gets stuck once set and liteon blueray rom iHOS104-08
violates ATA specification and fails to set I on D2H Reg FIS if nIEN
is set when the command was issued. When the other party is following
the spec, both devices can work fine but when the two flaws are put
together, they can't talk to each other.
mcp55 has its own IRQ masking mechanism and there's no reason to mess
with nIEN in the first place. Fix it by dropping nIEN diddling from
nv_mcp55_freeze/thaw().
This was originally reported by Cengiz. Although Cengiz hasn't
verified the fix yet, I could reproduce this problem and verfiy the
fix. Even if Cengiz is experiencing different or additional problems,
this patch is needed.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Cengiz Günay <cgunay@emory.edu>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
vt6421 has problems talking to recent WD drives. It causes a lot of
transmission errors while high bandwidth transfer as reported in the
following bugzilla entry.
https://bugzilla.kernel.org/show_bug.cgi?id=15173
Joseph Chan provided the following fix. I don't have any idea what it
does but I can verify the issue is gone with the patch applied.
Signed-off-by: Tejun Heo <tj@kernel.org>
Originally-from: Joseph Chan <JosephChan@via.com.tw>
Reported-by: Jorrit Tijben <sjorrit@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Grant patches added an of mach table to struct device_driver. However,
while he changed the macio device code to use that, he left the match
table pointer in struct macio_driver and didn't update drivers to use
the "new" one, thus breaking the probing.
This completes the change by moving all drivers to setup the "new"
one, removing all traces of the old one, and while at it (since it
changes the exact same locations), I also remove two other duplicates
from struct driver which are the name and owner fields.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This fixes a sporadic oops at boot on G5 Power Macs. The table_end
variable has the address of the last byte of the table. Adding on
PAGE_SIZE means we flush too much, and if the page after the table
is not mapped for any reason, the kernel will oops. Instead we add
on 1 because flush_dcache_range() interprets its second argument as
the first byte past the range to be flushed.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
PWRficient platform work is definitely in maintenance mode these
days, update MAINTAINERS file to reflect reality.
Website is long gone as well.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Fix smatch warning: warning: constant 0x800000000 is so big it is long
Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
emulate_step() in kprobe_handler() would've already determined if the
probed instruction can be emulated. We single-step in hardware only if
the instruction couldn't be emulated. resume_execution() therefore is
superfluous -- all we need is to fix up the instruction pointer after
single-stepping.
Thanks to Paul Mackerras for catching this.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Fixes bug introduced by commit 61c7a080a5
(of: Always use 'struct device.of_node' to get device node pointer)
Signed-off-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Percpu initialization happens now after booting the cores on the
machine and this causes them all to be displayed as belonging to
node 0:
Jun 8 05:57:21 kepek kernel: [ 0.106999] Booting Node 0,
Processors #1#2#3#4#5#6#7#8#9#10#11#12#13#14#15#16#17#18#19#20#21#22#23 Ok.
Use early_cpu_to_node() to get the correct node of each core
instead.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Cc: Mike Travis <travis@sgi.com>
LKML-Reference: <20100601190455.GA14237@aftab>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
powerpc: Don't export cvt_fd & _df when CONFIG_PPC_FPU is not set
powerpc/44x: icon: select SM502 and frame buffer console support
powerpc/85xx: Add P1021MDS board support
powerpc/85xx: Change MPC8572DS camp dtses for MSI sharing
powerpc/fsl_msi: add removal path and probe failing path
powerpc/fsl_msi: enable msi sharing through AMP OSes
powerpc/fsl_msi: enable msi allocation in all banks
powerpc/fsl_msi: fix the conflict of virt_msir's chip_data
powerpc/fsl_msi: Add multiple MSI bank support
powerpc/kexec: Add support for FSL-BookE
powerpc/fsl-booke: Move the entry setup code into a seperate file
powerpc/fsl-booke: fix the case where we are not in the first page
powerpc/85xx: Enable support for ports 3 and 4 on 8548 CDS
powerpc/fsl-booke: Add hibernation support for FSL BookE processors
powerpc/e500mc: Implement machine check handler.
powerpc/44x: Add basic ICON PPC440SPe board support
powerpc/44x: Fix UART clocks on 440SPe
powerpc/44x: Add reset-type to katmai.dts
powerpc/44x: Adding PCI-E support for PowerPC 460SX based SOC.
* 'drm-intel-next' of git://git.kernel.org/pub/scm/linux/kernel/git/anholt/drm-intel: (41 commits)
drm/i915: add HAS_BSD check to i915_getparam
drm/i915: Honor sync polarity from VBT panel timing descriptors
drm/i915: Unmask interrupt for render engine on Sandybridge
drm/i915: Fix PIPE_CONTROL command on Sandybridge
drm/i915: Fix up address spaces in slow_kernel_write()
drm/i915: Use non-atomic kmap for slow copy paths
drm/i915: Avoid moving from CPU domain during pwrite
drm/i915: Cleanup after failed initialization of ringbuffers
drm/i915: Reject bind_to_gtt() early if object > aperture
drm/i915: Check error code whilst moving buffer to GTT domain.
drm/i915: Remove spurious warning "Failure to install fence"
drm/i915: Rebind bo if currently bound with incorrect alignment.
drm/i915: Include pitch in set_base debug statement.
drm/i915: Only print "nothing to do" debug message as required.
drm/i915: Propagate error from unbinding an unfenceable object.
drm/i915: Avoid nesting of domain changes when setting display plane
drm/i915: Hold the spinlock whilst resetting unpin_work along error path
drm/i915: Only print an message if there was an error
drm/i915: Clean up leftover bits from hws move to ring structure.
drm/i915: Add CxSR support on Pineview DDR3
...
fscache_write_op() makes unnecessary checks of the page variable to see if it
is NULL. It can't be NULL at those points as the kernel would already have
crashed a little higher up where we examined page->index.
Furthermore, unless radix_tree_gang_lookup_tag() can return 1 but no page, a
NULL pointer crash should not be encountered there as we can only get there if
r_t_g_l_t() returned 1.
Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When we use plain 'perf buildid-list' we use only what is in the buildid
table in the perf.data header. And those have absolute pathnames because
at 'perf record' time we used __perf_session__process_events and that
doesn't sets up the path shortening code in map__new() that happens if
symbol_conf.full_paths is false, the default.
On the other hand, when we use 'perf buildid-list --with-hits' we
process all the events using perf_session__process_events, adding
entries to the global DSO list _after_ removing the current directory
from the DSO name, for presentation purposes.
Because of that we end up having two entries in the DSO list when
recording events for binaries using relative pathnames.
Fix it minimally by setting symbol_conf.full_paths to true when marking
the DSOs with hits in 'perf buildid-list --with-hits', as used by 'perf
archive'
Right fix longer term is to shorten the path only at presentation time.
Will be done for 2.6.36.
Reported-by: Stephane Eranian <eranian@google.com>
Tested-by: Stephane Eranian <eranian@google.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <20100601183837.GC4093@ghostprotocols.net>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This will let userland only try to use the new media decode
functionality when the appropriate kernel is present.
Signed-off-by: Zou Nan hai <nanhai.zou@intel.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
I'm actually kind of shocked that it works at all otherwise.
Signed-off-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Commit 315e995c63 is causing OOM kills
when stress-testing a CIFS filesystem. The VFS readpages operation takes
a page reference. The older code just handed this reference off to the
page cache, but the new code takes an extra one. The simplest fix is to
put the new reference after add_to_page_cache_lru.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>
We should only build hpet_example on x86[-64], where it is implemented.
It can cause build errors on other architectures.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix a possible null pointer dereference in afs_alloc_server(): the server
pointer is NULL if there was an allocation failure, and under such a
condition, we can't dereference it in the _leave() statement.
Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In commit e9fb7631eb ("cpu-hotplug: introduce cpu_notify(),
__cpu_notify(), cpu_notify_nofail()") the new helper functions access
cpu_chain. As a result, it shouldn't be marked __cpuinitdata (via
section mismatch warning).
Alternatively, the helper functions should be forced inline, or marked
__ref or __cpuinit. In the meantime, this patch silences the warning
the trivial way.
Signed-off-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-35' of git://repo.or.cz/linux-kbuild: (81 commits)
kbuild: Revert part of e8d400a to resolve a conflict
kbuild: Fix checking of scm-identifier variable
gconfig: add support to show hidden options that have prompts
menuconfig: add support to show hidden options which have prompts
gconfig: remove show_debug option
gconfig: remove dbg_print_ptype() and dbg_print_stype()
kconfig: fix zconfdump()
kconfig: some small fixes
add random binaries to .gitignore
kbuild: Include gen_initramfs_list.sh and the file list in the .d file
kconfig: recalc symbol value before showing search results
.gitignore: ignore *.lzo files
headerdep: perlcritic warning
scripts/Makefile.lib: Align the output of LZO
kbuild: Generate modules.builtin in make modules_install
Revert "kbuild: specify absolute paths for cscope"
kbuild: Do not unnecessarily regenerate modules.builtin
headers_install: use local file handles
headers_check: fix perl warnings
export_report: fix perl warnings
...
* 'for-linus' of git://www.jni.nu/cris:
CRIS: Don't use mask_irq as symbol name
CRIS: Simplify param.h by simply including <asm-generic/param.h>
CRISv10: Whitespace fixes for hw_settings.S
CRISv10: Trivial fixes.
CRISv32: Fix RS485 port 4 CD Kconfig item.
CRISv32: Remove duplicated Kconfig items.
cris: push down BKL into some device drivers
Commands with data must set the length in the message.
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (28 commits)
drivers/isdn/hardware/mISDN: Use GFP_ATOMIC when a lock is held
ksz884x: Add missing validate_addr hook
ksz884x: convert to netdev_tx_t
virtio-net: pass gfp to add_buf
be2net: convert hdr.timeout in be_cmd_loopback_test() to le32
can: mpc5xxx_can.c: Fix build failure
net/ipv4/tcp_input.c: fix compilation breakage when FASTRETRANS_DEBUG > 1
net: sock_queue_err_skb() dont mess with sk_forward_alloc
netfilter: xtables: stackptr should be percpu
netfilter: don't xt_jumpstack_alloc twice in xt_register_table
greth: Fix build after OF device conversions.
net: fix sk_forward_alloc corruptions
Phonet: listening socket lock protects the connected socket list
caif: unlock on error path in cfserl_receive()
be2net: remove superfluous externs
be2net: add unlock on error path
net/rds: Add missing mutex_unlock
drivers/isdn/hardware/mISDN: Add missing spin_unlock
fs_enet: Adjust BDs after tx error
skb: make skb_recycle_check() return a bool value
...
clear_user() returns the number of bytes that could not be copied rather than
an error code. So we should return -EFAULT rather than directly returning the
results.
Without this patch, positive values may be returned to elf_fdpic_map_file()
and the following error handlings do not function as expected.
1.
ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
if (ret < 0)
return ret;
2.
ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
if (ret < 0)
return ret;
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
CC: Alexander Viro <viro@zeniv.linux.org.uk>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
CC: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
trace_unhandled() callback does not allow to access event fields, this patch
resolves the problem.
It can also been used as a more pythonic and flexible way for script writters
to demux event types
This will for example greatly simplify pytimechart event demux.
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Tom Zanussi <tzanussi@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>,
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <1275340329-2397-1-git-send-email-tardyp@gmail.com>
Signed-off-by: Pierre Tardy <tardyp@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
hist_entry__annotate() runs objdump with -S option so the output may contain
lines of any format. If a line starts with a colon strtoull() returns 0 and
calculated offset will be negative. This causes perf annotate segfaults.
Make sure that strtoull() has parsed at least one digit.
Cc: David S. Miller <davem@davemloft.net>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Zanussi <tzanussi@gmail.com>
LKML-Reference: <new-submission>
Signed-off-by: Konstantin Stepanyuk <konstantin.stepanyuk@gmail.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch implements a fallback to the GART IOMMU if this
is possible and the AMD IOMMU initialization failed.
Otherwise the fallback would be nommu which is very
problematic on machines with more than 4GB of memory or
swiotlb which hurts io-performance.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
When request_mem_region fails the error path tries to
disable the IOMMUs. This accesses the mmio-region which was
not allocated leading to a kernel crash. This patch fixes
the issue.
Cc: stable@kernel.org
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
For CONFIG_PREEMPT=y kernels the sched_switch(.prev_state) argument isn't
useful because we can get preempted with current->state != TASK_RUNNING
without actually getting removed from the runqueue.
Cure this by treating all preempted tasks as runnable from the tracer's
point of view.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cautiously-acked-by: Steven Rostedt <rostedt@goodmis.org>
LKML-Reference: <1275322715.27810.23323.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Mike reports that since e9e9250b (sched: Scale down cpu_power due to RT
tasks), wake_affine() goes funny on RT tasks due to them still having a
!0 weight and wake_affine() still subtracts that from the rq weight.
Since nobody should be using se->weight for RT tasks, set the value to
zero. Also, since we now use ->cpu_power to normalize rq weights to
account for RT cpu usage, add that factor into the imbalance computation.
Reported-by: Mike Galbraith <efault@gmx.de>
Tested-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1275316109.27810.22969.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The function inittiger is only called from nj_init_card, where a lock is held.
The semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@gfp exists@
identifier fn;
position p;
@@
fn(...) {
... when != spin_unlock_irqrestore
when any
GFP_KERNEL@p
... when any
}
@locked@
identifier gfp.fn;
@@
spin_lock_irqsave(...)
... when != spin_unlock_irqrestore
fn(...)
@depends on locked@
position gfp.p;
@@
- GFP_KERNEL@p
+ GFP_ATOMIC
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
virtio-net bounces buffer allocations off to
a thread if it can't allocate buffers from the atomic
pool. However, if posting buffers still requires atomic
buffers, this is unlikely to succeed.
Fix by passing in the proper gfp_t parameter.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current code fails on ppc as hdr.timeout is not being converted
to le32.
Signed-off-by: Sathya Perla <sathyap@serverengines.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Grant Likely
Anatolij Gustschin
Michael Guntsche
Tejun Heo
Stefan Richter
Benjamin Herrenschmidt
Paul Mackerras
Olof Johansson
Denis Kirjanov
Ananth N Mavinakayanahalli
Andreas Schwab
Alexandre Bounine
Borislav Petkov
Ingo Molnar
Linus Torvalds
Dan Carpenter
Arnaldo Carvalho de Melo
Zou Nan hai
Adam Jackson
Jeff Layton
Randy Dunlap
Daniel J Blueman
Alan Cox
Takuya Yoshikawa
Pierre Tardy
Konstantin Stepanyuk
Joerg Roedel
Peter Zijlstra
Julia Lawall
Michael S. Tsirkin
Sathya Perla