We have a bunch of CONFIG_PPC_EARLY_DEBUG_* options that are intended
for bringup/debug only. They hard wire a machine specific udbg backend
very early on (before we even probe the platform), and use whatever
tricks are available on each machine/cpu to be able to get some kind
of output out there early on.
So far, on powermac with no serial ports, we have CONFIG_PPC_EARLY_DEBUG_BOOTX
to use the low-level btext engine on the screen, but it doesn't do much, at
least on 64-bit. It only really gets enabled after the platform has been
probed and the MMU enabled.
This adds a way to enable it much earlier. From prom_init.c (while still
running with Open Firmware), we grab the screen details and set things up
using the physical address of the frame buffer.
Then btext itself uses the "rm_ci" feature of the 970 processor (Real
Mode Cache Inhibited) to access it while in real mode.
We need to do a little bit of reorg of the btext code to inline things
better, in order to limit how much we touch memory while in this mode as
the consequences might be ... interesting.
This successfully allowed me to debug problems early on with the G5
(related to gold being broken vs. ppc64 kernels).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
pci_read_bridge_bases() already checks if the PCI bus is root
bus or not, so we needn't do same check in pcibios_fixup_bus()
and just remove it.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
PHB3 doesn't support IO ports and we needn't IO segment map for that.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The index of one specific PCI controller (struct pci_controller::
global_number) can tell that it's primary one or not. So we needn't
additional variable for that and just remove it.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
The patch enables fetching bus range from device-tree for the
specific PHB. If we can't get that from device-tree, the default
range [0 255] will be used.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We don't free PHB instance (struct pnv_phb) on error to creating
the associated PCI controler (struct pci_controller). The patch
fixes that. Also, the output messages have been cleaned for a bit
so that they looks unified for IODA_1/2 cases.
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Since 2002, the kernel has not saved VRSAVE on exception entry and
restored it on exit; rather, VRSAVE gets context-switched in _switch.
This means that when executing in process context in the kernel, the
userspace VRSAVE value is live in the VRSAVE register.
However, the signal code assumes that current->thread.vrsave holds
the current VRSAVE value, which is incorrect. Therefore, this
commit changes it to use the actual VRSAVE register instead. (It
still uses current->thread.vrsave as a temporary location to store
it in, as __get_user and __put_user can only transfer to/from a
variable, not an SPR.)
This also modifies the transactional memory code to save and restore
VRSAVE regardless of whether VMX is enabled in the MSR. This is
because accesses to VRSAVE are not controlled by the MSR.VEC bit,
but can happen at any time.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Other architectures have a __get_user_pages_fast(), in addition to the
regular get_user_pages_fast(), which doesn't call get_user_pages() on
failure, and thus doesn't attempt to fault pages in or COW them. The
generic KVM code uses __get_user_pages_fast() to detect whether a page
for which we have only requested read access is actually writable.
This provides an implementation of __get_user_pages_fast() by
splitting the existing get_user_pages_fast() in two. With this, the
generic KVM code will get the right answer instead of always
considering such pages non-writable.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit adds a test of instruction counting using the PMU on powerpc.
Although the bulk of the code is architecture agnostic, the code needs to
run a precisely sized loop which is implemented in assembler.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit adds support code used by upcoming powerpc tests.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit adds a powerpc subdirectory to tools/testing/selftests,
for tests that are powerpc specific.
On other architectures nothing is built. The makefile supports cross
compilation if the user sets ARCH and CROSS_COMPILE.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
T4, Cell, powernv, and pseries had the same implementation, so switch
them to use a generic version. A2 apparently had a version, but
removed it at some point, so we remove the declaration, too.
Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cell and PSeries both implemented their own versions of a
cpu_bootable smp_op which do the same thing (well, the PSeries
one has support for more than 2 threads). Copy the PSeries one
to generic code, and rename it smp_generic_cpu_bootable.
Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
And now the function flush_icache_range() is just a wrapper which
only invoke the function __flush_icache_range() directly. So we
don't have reason to keep it anymore.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
In function flush_icache_range(), we use cpu_has_feature() to test
the feature bit of CPU_FTR_COHERENT_ICACHE. But this seems not optimal
for two reasons:
a) For ppc32, the function __flush_icache_range() already do this
check with the macro END_FTR_SECTION_IFSET.
b) Compare with the cpu_has_feature(), the method of using macro
END_FTR_SECTION_IFSET will not introduce any runtime overhead.
[And while at it, add the missing required isync] -- BenH
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Although the shared_proc field in the lppaca works today, it is
not architected. A shared processor partition will always have a non
zero yield_count so use that instead. Create a wrapper so users
don't have to know about the details.
In order for older kernels to continue to work on KVM we need
to set the shared_proc bit. While here, remove the ugly bitfield.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Fix a sparse warning about force_32bit_msi being a one bit bitfield.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Address some of the trivial sparse warnings in arch/powerpc.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
plpar_get_term_char is only used once and just adds a layer
of complexity to H_GET_TERM_CHAR. plpar_put_term_char isn't
used at all so we can remove it.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Simplify things by putting all the 32bit and 64bit defines
together instead of in two spots.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
We always use VMX loads and stores to manage the high 32
VSRs. Remove these unused macros.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Not having parentheses around a macro is asking for trouble.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Normally when we haven't implemented an alignment handler for
a load or store instruction the process will be terminated.
The alignment handler uses the DSISR (or a pseudo one) to locate
the right handler. Unfortunately ldbrx and stdbrx overlap lfs and
stfs so we incorrectly think ldbrx is an lfs and stdbrx is an
stfs.
This bug is particularly nasty - instead of terminating the
process we apply an incorrect fixup and continue on.
With more and more overlapping instructions we should stop
creating a pseudo DSISR and index using the instruction directly,
but for now add a special case to catch ldbrx/stdbrx.
Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
p_toc is an 8 byte relative offset to the TOC that we place in the
text section. This means it is only 4 byte aligned where it should
be 8 byte aligned. Add an explicit alignment.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
If CONFIG_E500 is enabled, the compilation flags are updated
specifying the target core -mcpu=e5500/e500mc/8540
Also remove -Wa,-me500, being incompatible with -mcpu=e5500/e6500
The assembler option is redundant if the -mcpu= flag is set.
The patch fixes the kernel compilation problem for e5500/e6500
when using gcc option -mcpu=e5500/e6500.
Signed-off-by: Catalin Udma <catalin.udma@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
When using recent udev, the /dev node mount requires CONFIG_DEVTMPFS_MOUNT
is enabled in Kernel. The patch enables the option in defconfig of Freescale
QorIQ targets.
Changed defconfig list:
arch/powerpc/configs/85xx/p1023rds_defconfig
arch/powerpc/configs/corenet32_smp_defconfig
arch/powerpc/configs/corenet64_smp_defconfig
arch/powerpc/configs/mpc85xx_smp_defconfig
arch/powerpc/configs/mpc85xx_defconfig
arch/powerpc/configs/mpc83xx_defconfig
Signed-off-by: Zhenhua Luo <zhenhua.luo@freescale.com>
[scottwood@freescale.com: added mpc83xx and non-smp mpc85xx]
Signed-off-by: Scott Wood <scottwood@freescale.com>
For Freescale powerpc platform, the PCI-e bus number uses the reassign mode
by default. It means the second PCI-e controller's hose->first_busno is the
first controller's last bus number adding 1. For some hotpluged device(or
controlled by FPGA), the device is linked to PCI-e slot at linux runtime.
It needs rescan for the system to add it and driver it to work. It successes
to rescan the device linked to the first PCI-e controller's slot, but fails to
rescan the device linked to the second PCI-e controller's slot. The cause is
that the bus->number is reset to 0, which isn't equal to the hose->first_busno
for the second controller checking PCI-e link. So it doesn't really check the
PCI-e link status, the link status is always no_link. The device won't be
really rescaned. Reset the bus->number to hose->first_busno in the function
fsl_pcie_check_link(), it will do the real checking PCI-e link status for the
second controller, the device will be rescaned.
Signed-off-by: Yuanquan Chen <Yuanquan.Chen@freescale.com>
Tested-by: Rojhalat Ibrahim <imr@rtschenk.de>
Signed-off-by: Scott Wood <scottwood@freescale.com>
This function contains all the stuff we need to check if SWIOTLB
should be enabled or not. So it is more convenient to enable
the SWIOTLB here than later.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
The (1ull << mem_log) is never greater than mem unless mem_log++;
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
The function pci_devs_phb_init is invoked more earlier than we really
probe the pci controller, so it does nothing at all. And we also don't
need the pci_dn stuff for the fsl powerpc64 boards, just remove it.
It also seems that we don't support ISA on all the current corenet ds
boards. So picking a primary bus seems useless, remove that function
too.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
The p1020rdb-pd has the similar feature as the p1020rdb.
Therefore, p1020rdb-pd use the same platform file as the p1/p2 rdb board.
Overview of P1020RDB-PD platform:
- DDR3 2GB
- NOR flash 64MB
- NAND flash 128MB
- SPI flash 16MB
- I2C EEPROM 256Kb
- eTSEC1 (RGMII PHY) connected to VSC7385 L2 switch
- eTSEC2 (SGMII PHY)
- eTSEC3 (RGMII PHY)
- SDHC
- 2 USB ports
- 4 TDM ports
- PCIe
Signed-off-by: Haijun Zhang <Haijun.Zhang@freescale.com>
Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
CC: Scott Wood <scottwood@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
At console init, when the kernel tries to flush the log buffer
the ePAPR byte-channel based console write fails silently,
losing the buffered messages.
This happens because The ePAPR para-virtualization init isn't
done early enough so that the hcall instruction to be set,
causing the byte-channel write hcall to be a nop.
To fix, change the ePAPR para-virt init to use early device
tree functions and move it in early init.
Signed-off-by: Laurentiu Tudor <Laurentiu.Tudor@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
The original MPIC MSI bank contains 8 registers, MPIC v4.3 MSI bank
contains 16 registers, and this patch adds NR_MSI_REG_MAX and
NR_MSI_IRQS_MAX to describe the maximum capability of MSI bank.
MPIC v4.3 provides MSIIR1 to index these 16 MSI registers. MSIIR1
uses different bits definition than MSIIR. This patch adds
ibs_shift and srs_shift to indicate the bits definition of the
MSIIR and MSIIR1, so the same code can handle the MSIIR and MSIIR1
simultaneously.
Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
[scottwood@freescale.com: reinstated static on all_avail]
Signed-off-by: Scott Wood <scottwood@freescale.com>
For the latest platform T4 and B4, MPIC controller has been updated
to v4.3. This patch adds a new file to describe the latest MPIC.
The MSI blocks number is increased to four, the registers number
of each block is increased to sixteen. MSIIR1 has been added to
access these sixteen MSI registers.
Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Add compatible "fsl,mpic-msi-v4.3" for MPIC v4.3. MPIC v4.3 contains
MSIIR and MSIIR1. MSIIR supports 8 MSI registers and MSIIR1 supports
16 MSI registers, but uses different IBS and SRS shift. When using
MSIR1, the interrupt number is not consecutive. It is hard to use
'msi-available-ranges' to describe the ranges of the available
interrupt, so MPIC v4.3 does not support this property.
Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
[scottwood@freescale.com: minor grammar fixes]
Signed-off-by: Scott Wood <scottwood@freescale.com>
mpic_get_primary_version() is not defined when not using MPIC.
The compile error log like:
arch/powerpc/sysdev/built-in.o: In function `fsl_of_msi_probe':
fsl_msi.c:(.text+0x150c): undefined reference to `fsl_mpic_primary_get_version'
Signed-off-by: Jia Hongtao <hongtao.jia@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
e6500 core performance monitors has the following features:
- 6 performance monitor counters
- 512 events supported
- no threshold events
e6500 PMU has more specific events (Data L1 cache misses, Instruction L1
cache misses, etc ) than e500 PMU (which only had Data L1 cache reloads,
etc). Where available, the more specific events have been used which will
produce slightly different results than e500 PMU equivalents.
Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
Signed-off-by: Lijun Pan <Lijun.Pan@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
There are 6 counters in e6500 core instead of 4 in e500 core.
Signed-off-by: Lijun Pan <Lijun.Pan@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
This change is required after the e6500 perf support has been added.
There are 6 counters in e6500 core instead of 4 in e500 core and
the MAX_HWEVENTS counter should be changed accordingly from 4 to 6.
Added also runtime check for counters overflow.
Signed-off-by: Catalin Udma <catalin.udma@freescale.com>
Signed-off-by: Lijun Pan <Lijun.Pan@freescale.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
This file is a common include for B4860 and B4420 but is not a valid DTS itself:
DTC arch/powerpc/boot/b4qds.dtb
Error: arch/powerpc/boot/dts/b4qds.dts:35.1-2 syntax error
FATAL ERROR: Unable to parse input tree
make[1]: *** [arch/powerpc/boot/b4qds.dtb] Error 1
make: *** [b4qds.dtb] Error 2
I spotted in build tests of device-tree.git, announcement
https://lkml.org/lkml/2013/4/24/209, which builds *.dts. Probably no one would
do this this in real life on linux.git but it still seems worth fixing.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Shaveta Leekha <shaveta@freescale.com>
Cc: Minghuan Lian <Minghuan.Lian@freescale.com>
Cc: Andy Fleming <afleming@freescale.com>
Cc: Poonam Aggrwal <poonam.aggrwal@freescale.com>
Cc: Ramneek Mehresh <ramneek.mehresh@freescale.com>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Scott Wood <scottwood@freescale.com>
lead to race conditions between deleting an event and accessing an event
debugfs file. This included a fix to the debugfs system (acked by
Greg Kroah-Hartman). We think that all the holes have been patched and
hopefully we don't find more. I haven't marked all of them for stable
because I need to examine them more to figure out how far back some of
the changes need to go.
Along the way, some other fixes have been made. Alexander Z Lam fixed
some logic where the wrong buffer was being modifed.
Andrew Vagin found a possible corruption for machines that actually
allocate cpumask, as a reference to one was being zeroed out by mistake.
Dhaval Giani found a bad prototype when tracing is not configured.
And I not only had some changes to help Oleg, but also finally fixed
a long standing bug that Dave Jones and others have been hitting, where
a module unload and reload can cause the function tracing accounting
to get screwed up.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.14 (GNU/Linux)
iQEcBAABAgAGBQJR/7FvAAoJEOdOSU1xswtMCAgH/RpxS5mQcQnhrGfu1qnSk+3v
CyL1X9IkvgP5f+N59tbU3ZuE8Q3YQvTII35na38fgbHbwWrhYjLSvlf3Pwtre8zr
Rjm9b8zA6iSobHu3DyuuupzMsLE+SpBakVSmG6mi8izZyuCi0YHMZMnHTGNnW9Vv
YFqkfGgQQWMqiUHLcueetOqWAjR2JiJaLfr47rsRLNflF6dB2MbG/7YbYJ0TBk7E
hemVmR7JH7606eJZ6nR7bh/hYv0sL2SSqVVaOHO5nWFLFbI8CybpNVGcoD+nihZY
M7LrZT1C1mn3nKrfDhyXy4dwwx6wBON0fY23eJTHMVNnc0tvY1xqH52vTdPILWg=
=UfsE
-----END PGP SIGNATURE-----
Merge tag 'trace-fixes-3.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Oleg Nesterov has been working hard in closing all the holes that can
lead to race conditions between deleting an event and accessing an
event debugfs file. This included a fix to the debugfs system (acked
by Greg Kroah-Hartman). We think that all the holes have been patched
and hopefully we don't find more. I haven't marked all of them for
stable because I need to examine them more to figure out how far back
some of the changes need to go.
Along the way, some other fixes have been made. Alexander Z Lam fixed
some logic where the wrong buffer was being modifed.
Andrew Vagin found a possible corruption for machines that actually
allocate cpumask, as a reference to one was being zeroed out by
mistake.
Dhaval Giani found a bad prototype when tracing is not configured.
And I not only had some changes to help Oleg, but also finally fixed a
long standing bug that Dave Jones and others have been hitting, where
a module unload and reload can cause the function tracing accounting
to get screwed up"
* tag 'trace-fixes-3.11-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix reset of time stamps during trace_clock changes
tracing: Make TRACE_ITER_STOP_ON_FREE stop the correct buffer
tracing: Fix trace_dump_stack() proto when CONFIG_TRACING is not set
tracing: Fix fields of struct trace_iterator that are zeroed by mistake
tracing/uprobes: Fail to unregister if probe event files are in use
tracing/kprobes: Fail to unregister if probe event files are in use
tracing: Add comment to describe special break case in probe_remove_event_call()
tracing: trace_remove_event_call() should fail if call/file is in use
debugfs: debugfs_remove_recursive() must not rely on list_empty(d_subdirs)
ftrace: Check module functions being traced on reload
ftrace: Consolidate some duplicate code for updating ftrace ops
tracing: Change remove_event_file_dir() to clear "d_subdirs"->i_private
tracing: Introduce remove_event_file_dir()
tracing: Change f_start() to take event_mutex and verify i_private != NULL
tracing: Change event_filter_read/write to verify i_private != NULL
tracing: Change event_enable/disable_read() to verify i_private != NULL
tracing: Turn event/id->i_private into call->event.type
Pull libata fix from Tejun Heo:
"Just the addition of MODULE_DEVICE_TABLE() for a platform driver"
* 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/libata:
pata_imx: expose module alias for loading from device-tree
Pull cgroup fix from Tejun Heo:
"Fix for a minor memory leak bug in the cgroup init failure path"
* 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: fix a leak when percpu_ref_init() fails
Pull two workqueue fixes from Tejun Heo:
"A lockdep notation update so that nested work_on_cpu() invocations
don't lead to spurious lockdep warnings and fix for an unbound attr
bug which made what's shown in sysfs deviate from the actual ones.
Both patches have pretty limited scope"
* 'for-3.11-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: copy workqueue_attrs with all fields
workqueue: allow work_on_cpu() to be called recursively
Pull misc x86 fixes from Peter Anvin.
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, amd, microcode: Fix error path in apply_microcode_amd()
x86, fpu: correct the asm constraints for fxsave, unbreak mxcsr.daz
x86, efi: correct call to free_pages
x86/iommu/vt-d: Expand interrupt remapping quirk to cover x58 chipset
Some of my configs I test with have CONFIG_A11Y_BRAILLE_CONSOLE set.
When I started testing against v3.11-rc4 my console went bonkers. Using
ktest to bisect the issue, it came down to:
commit bbeddf52a "printk: move braille console support into separate
braille.[ch] files"
Looking into the patch I found the problem. It's with the return of
braille_register_console(). As anything other than NULL is considered a
failure.
But for those of us that have CONFIG_A11Y_BRAILLE_CONSOLE set but do not
define a "brl" or "brl=" on the command line, we still may want a
console that those with sight can still use.
Return NULL (success) if "brl" or "brl=" is not on the console line.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
