Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like
In this patch, we provide SMP extend to some other misc code
Singed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like
In this patch, we provide SMP extend to Blackfin kernel and memory management code
Singed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like
In this patch, we provide SMP extend to Blackfin CPLB related code
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like
In this patch, we provide SMP extend to Blackfin header files
and machine common code
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Blackfin dual core BF561 processor can support SMP like features.
https://docs.blackfin.uclinux.org/doku.php?id=linux-kernel:smp-like
In this patch, we provide SMP extend to BF561 kernel code
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
- This patch adds support for ARCH_WANT_OPTIONAL_GPIOLIB.
- It may be changed in future to ARCH_REQUIRE_GPIOLIB.
- Change GPIO_BANK_NUM use DIV_ROUND_UP( , ) macro
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
- Remove SSYNC()
- Use irq_to_gpio where applicable
- Remove gpio_edge_triggered bitfield, check irq_desc fields instead.
- Remove gpio_both_edge_triggeredb bitfield, check irq_desc fields
instead.
- Use BITMAP and bitops on gpio_enabled
- Preferably use 32-bit
- Looking at the disassembly this indeed saves quite a few instructions.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
- remove SSYNC() left over from irq init split
- do not force SSYNC() when masking/unmasking IRQs in the SIC
as any order enforced by the hardware should already be enforced
by software
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
The whole story:
Before BF51x merged, all the MAX_BLACKFIN_GPIOS are integral multiple of GPIO_BANKSIZE (= 16).
But BF51x provides MAX_BLACKFIN_GPIOS = 40 which includes 3 banks and the 3rd bank has only 8
GPIO pins.
Therefore, gpio_bank() macros is correct when you try to find a GPIO in which bank (GPIO_35 is
in bank 2). But on BF51x gpio_bank(MAX_BLACKFIN_GPIOS) only gives out 2 banks instead of 3
banks for some static array initialization.
This patch add a new macros gpio_bank_n() and GPIO_BANK_NUM to do bank number caculating and
remain the gpio_bank() macros for positioning a gpio in which bank.
Signed-off-by: Bryan Wu <cooloney@kernel.org>
- to avoid uninitialized errors
- make invalid sizes a build error
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
our kernel should be sane now, and we want to catch NULL bugs,
not ignore them
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
- do not bother generating deprecated /sys files by default now since
mdev does not need it
- Don't built-in char sport driver and build it as a module in defconfig
- disable CONFIG_DEVKMEM by default
- enable spi flash driver on boards that have one
- switch config to the NAND platfrom driver rather than the bfin async one
- do not make BFIN_DMA_5XX optional since a large portion of our code relies
on dma functions existing
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Add irq to struct dma_channel lookup channel2irq() only once,
since channel2irq() is fairly large on some Blackfin derivatives.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
refine the gpio check in peripheral_request() so that it only
checks pins that can be used as both GPIO and a peripheral
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
The original code defined _exception_stack but not alloc space for the exception
stack. In exception, this area is over written by exception stack. Common kernel
luckly boot up, but SMP kernel stuck.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Make sure IFLUSH is not the last instruction in the hardware loop to avoid
infinite core stall.
The dcache/icache function that only gets used in writeback mode was putting
IFLUSH as the last instruction in the hardware loop ... we know from design
that this may often lead to inifite core stalling, so switch the FLUSH/IFLUSH
order.
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
The cache code I added flushes 1 line too little if the start address is
not aligned to the cache size. Cache align the start address so that when
we straddle cache aligns, we get the right count.
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
allow people to stick exception stack into L1 scratch
and make sure it gets placed into .bss sections rather than .data
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
when copying L1 regions, go to the start of bss rather
than end since we have code to zero it out already
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
only if the cplb block overlapped with kernel area, this cplb need be locked
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
d_path() can return an error. Most of its callers do something or other to
make up something sane in that case. Do similar for blackfin's
decode_address() call to d_path().
Signed-off-by: Tim Pepper <lnxninja@linux.vnet.ibm.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
This patch implements a new freezer subsystem in the control groups
framework. It provides a way to stop and resume execution of all tasks in
a cgroup by writing in the cgroup filesystem.
The freezer subsystem in the container filesystem defines a file named
freezer.state. Writing "FROZEN" to the state file will freeze all tasks
in the cgroup. Subsequently writing "RUNNING" will unfreeze the tasks in
the cgroup. Reading will return the current state.
* Examples of usage :
# mkdir /containers/freezer
# mount -t cgroup -ofreezer freezer /containers
# mkdir /containers/0
# echo $some_pid > /containers/0/tasks
to get status of the freezer subsystem :
# cat /containers/0/freezer.state
RUNNING
to freeze all tasks in the container :
# echo FROZEN > /containers/0/freezer.state
# cat /containers/0/freezer.state
FREEZING
# cat /containers/0/freezer.state
FROZEN
to unfreeze all tasks in the container :
# echo RUNNING > /containers/0/freezer.state
# cat /containers/0/freezer.state
RUNNING
This is the basic mechanism which should do the right thing for user space
task in a simple scenario.
It's important to note that freezing can be incomplete. In that case we
return EBUSY. This means that some tasks in the cgroup are busy doing
something that prevents us from completely freezing the cgroup at this
time. After EBUSY, the cgroup will remain partially frozen -- reflected
by freezer.state reporting "FREEZING" when read. The state will remain
"FREEZING" until one of these things happens:
1) Userspace cancels the freezing operation by writing "RUNNING" to
the freezer.state file
2) Userspace retries the freezing operation by writing "FROZEN" to
the freezer.state file (writing "FREEZING" is not legal
and returns EIO)
3) The tasks that blocked the cgroup from entering the "FROZEN"
state disappear from the cgroup's set of tasks.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: export thaw_process]
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Acked-by: Serge E. Hallyn <serue@us.ibm.com>
Tested-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6:
Blackfin arch: make sure cycles is marked as volatile so gcc doesnt reorder on us
Blackfin arch: disable CONFIG_HW_RANDOM and CONFIG_DAB in defconfig files
Blackfin arch: update cache flush prototypes with argument names to make them less mysterious
Blackfin arch: move bfin_addr_dcachable() and friends into the cacheflush header where it belongs
Blackfin arch: use the new bfin_addr_dcachable() function
Blackfin arch: fix bug - build kernel failed at head.S when reprogram clock on all platforms
Blackfin arch: unify/cleanup cache code
Blackfin arch: update AD7879 platform resources in board file
Blackfin arch: Zero out bss region in L1/L2 memory.
Blackfin arch: add read/write IO accessor functions to Blackfin
Blackfin arch: fix bug - some serial header files set RTS to an input when they should all be outputs
- to be correct wrt to end ranges
- to be optimal with a one-instruction hardware loop
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
The SET_PERSONALITY macro is always called with a second argument of 0.
Remove the ibcs argument and the various tests to set the PER_SVR4
personality.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
As policy->governor is already set to CPUFREQ_DEFAULT_GOVERNOR in the
(always built-in) cpufreq core, we do not need to set it in the drivers.
This fixes the sparc64 allmodconfig build failure.
Also, remove a totally useles setting of ->policy in cpufreq-pxa3xx.c.
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6: (60 commits)
Blackfin arch: make sure we include the fix for SPORT hysteresis when reprogramming clocks
Blackfin arch: Fix bogus str_ident check in gpio code
Blackfin arch: AD7879 Touchscreen driver
Blackfin arch: introducing bfin_addr_dcachable
Blackfin arch: fix a typo in comments
Blackfin arch: Remove useless head file
Blackfin arch: make sure L2 start and length are always defined (fixes building on BF542)
Blackfin arch: use the Blackfin on-chip ROM to do software reset when possible
Blackfin arch: update anomaly headers to match the latest sheet
Blackfin arch: bfin_reset() is an internal reboot function ... everyone should go through machine_restart()
Blackfin arch: print out error/warning if you are running on the incorrect CPU type
Blackfin arch: remove non-bf54x ifdef logic since this file is only compiled on bf54x parts
Blackfin arch: update board defconfigs
Blackfin arch: Add optional verbose debug
Blackfin arch: emulate a TTY over the EMUDAT/JTAG interface
Blackfin arch: have is_user_addr_valid() check for overflows (like when address is -1)
Blackfin arch: ptrace - fix off-by-one check on end of memory regions
Blackfin arch: Enable framebuffer support for the BF526-EZkit TFT LCD display
Blackfin arch: flash memory map and dm9000 resources updating
Blackfin arch: early prink code still use uart core console functions to parse and set configure option string
...
* git://git.infradead.org/users/dwmw2/random-2.6:
Fix autoloading of MacBook Pro backlight driver.
Automatic MODULE_ALIAS() for DMI match tables.
Remove asm/a.out.h files for all architectures without a.out support.
Introduce HAVE_AOUT symbol to remove hard-coded arch list for BINFMT_AOUT
Remove redundant CONFIG_ARCH_SUPPORTS_AOUT
S390: Update comments about why we don't use <asm-generic/statfs.h>
SPARC: Use <asm-generic/statfs.h>
PowerPC: Use <asm-generic/statfs.h>
PARISC: Use <asm-generic/statfs.h>
x86_64: Use <asm-generic/statfs.h>
IA64: Use <asm-generic/statfs.h>
ARM: Use <asm-generic/statfs.h>
Make <asm-generic/statfs.h> suitable for 64-bit platforms.
Define and use PCI_DEVICE_ID_MARVELL_88ALP01_CCIC for CAFÉ camera driver
[MTD] [NAND] Define and use PCI_DEVICE_ID_MARVELL_88ALP01_NAND for CAFÉ
Use PCI_DEVICE_ID_88ALP01 for CAFÉ chip, rather than PCI_DEVICE_ID_CAFE.
EFS: Don't set f_fsid in statfs().
We now use the sir_dev/irtty_sir/uart/bfin_serial drivers framework
to monitor the TX status.
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
move common variables out of serial headers and into the serial driver and
rename "nr_ports" to "nr_active_ports" so as to easily differentiate
between BFIN_UART_NR_PORTS (the # of available) and nr_ports (the # of enabled)
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As pointed out by Appalayagari Sreedhar, make sure we include the fix
for SPORT hysteresis when reprogramming clocks.
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
This patch introduces bfin_addr_dcachable() predicate, that simply tests is
address in cachable region or not.
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Add optional verbose debug - which when turned off, quiets down
userspace errors. Saves ~8k of code/data for production systems
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Move all the silicon rev handling to one place (Kconfig) and
make sure we warn if you are running on silicon that has not been tested on
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
avoid using actual config name in comment as a text search
is done to see what files need to be rebuilt
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
The kernel does not properly clear the EBIU Error Master (EBIU_ERRMST) Register
on BF548, which causes the kernel to panic.
We need to make sure that we clear the EBIU_ERRMST (necessary on BF54x)
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
a global _sys_trace will cause the assembler to fail, it should be fixed in toolchain side firstly.
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Apply ANOMALY_05000283 & ANOMALY_05000315
Workaround also to the EXCEPTION path.
Cover evt_ivhw also with ANOMALY_05000315
The Workaround needs to be prior to accesses (either read or write) to
any system MMR.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
rename blackfin_sram.c to sram-alloc.c (we know it is a blackfin file,
since it is in arch/blackfin) - and there is no "driver" code in there,
it is just an allocator/deallocator for L1 and L2 sram.
Also fix a problem that checkpatch pointed out
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
use CONFIG_APP_STACKS_L1 to enable or disable putting kernel stacks in L1,
default is enabled, SMP kernel need turn it off
Signed-off-by: Graf Yang <graf.yang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Better error handling of unknown exceptions, allows userspace to do a
EXCPT n instruction for a not installed exception handler, and the
kernel doesn't crash (like it use to before this).
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Disable IRQs while frobbing the CPLB registers, to avoid accessing the
data in current_rwx_mask while it isn't covered by CPLBs.
Signed-off-by: Bernd Schmidt <bernds_cb1@t-online.de>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
This patch also includes the required removal of (unused) inclusion of
<asm/a.out.h> <linux/a.out.h>'s in the arch/ code for these
architectures.
[dwmw2: updated for 2.6.27-rc]
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Using just 'unsigned' will make flags an unsigned int. While this is
arguably not an error on blackfin where sizeof(int) == sizeof(long),
the patch is still justified on the grounds of principle.
The patch was generated using the Coccinelle semantic patch framework.
Cc: Julia Lawall <julia@diku.dk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
AFAIR there exists blackfin hardware with PCI support, but the support
currently in the kernel fails to build starting with:
...
CC drivers/pci/probe.o
probe.c: In function 'pci_scan_slot':
probe.c:1056: error: implicit declaration of function 'pcibios_scan_all_fns'
make[3]: *** [drivers/pci/probe.o] Error 1
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
- remove cheesy read_iloc() function
- move invalidate_entire_icache function to lock.S
- export proper prototypes for functions in lock.S
- only build lock.S when BFIN_ICACHE_LOCK is enabled
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
as pointed out by Michael McTernan in the forums, when expanding
the trace buffer, it does not print out the decoded instruction.
Signed-off-by: Robin Getz <rgetz@blackfin.uclinux.org>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
- Disable all bits in SIC_IWR unless we are going into a real (DPMC)
power saving mode. Any Interrupt can wake the core form it's idle state.
- Remove deep sleep mode as it is not going to be used anywhere:
We support sleep, sleep deeper and hibernate.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
- Skip single step if global interrupt disable bit is set.
- Extend bernds' patch r4673 to skip single step in any interrupt entry
that interrupts the code which is under single stepping. Bernds' patch
only allow user space single stepping.
Singed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
these are highly board specific, so putting into generic doesnt make much sense
Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6: (30 commits)
Blackfin arch: If we double fault, rather than hang forever, reset
Blackfin arch: When icache is off, make sure people know it
Blackfin arch: Fix bug - skip single step in high priority interrupt handler instead of disabling all interrupts in single step debugging.
Blackfin arch: cache the values of vco/sclk/cclk as the overhead of doing so (~24 bytes) is worth avoiding the software mult/div routines
Blackfin arch: fix bug - IMDMA is not type struct dma_register
Blackfin arch: check the EXTBANKS field of the DDRCTL1 register to see if we are using both memory banks
Blackfin arch: Apply Bluetechnix CM-BF527 board support patch
Blackfin arch: Add unwinding for stack info, and a little more detail on trace buffer
Blackfin arch: Add ISP1760 board resources to BF548-EZKIT
Blackfin arch: fix bug - detect 0.1 silicon revision BF527-EZKIT as 0.0 version
Blackfin arch: add missing IORESOURCE_MEM flags to UART3
Blackfin arch: Add return value check in bfin_sir_probe(), remove SSYNC().
Blackfin arch: Extend sram malloc to handle L2 SRAM.
Blackfin arch: Remove useless config option.
Blackfin arch: change L1 malloc to base on slab cache and lists.
Blackfin arch: use local labels and ENDPROC() markings
Blackfin arch: Do not need this dualcore test module in kernel.
Blackfin arch: Allow ptrace to peek and poke application data in L1 data SRAM.
Blackfin arch: Add ANOMALY_05000368 workaround
Blackfin arch: Functional power management support
...
Remove arch-specific show_mem() in favor of the generic version.
This also removes the following redundant information display:
- free pages, printed by show_free_areas()
- pages in swapcache, printed by show_swap_cache_info()
where show_mem() calls show_free_areas(), which calls
show_swap_cache_info().
Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
Acked-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Skip single step if event priority of current instruction is higher than
that of the first instruction, from which gdb starts single step.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
* 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
nohz: adjust tick_nohz_stop_sched_tick() call of s390 as well
nohz: prevent tick stop outside of the idle loop
Also includes a few Kconfig files (xtensa, blackfin)
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Remove the sram piece limitation and improve the performance to
alloc/free sram piece data.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Jack Ren and Eric Miao tracked down the following long standing
problem in the NOHZ code:
scheduler switch to idle task
enable interrupts
Window starts here
----> interrupt happens (does not set NEED_RESCHED)
irq_exit() stops the tick
----> interrupt happens (does set NEED_RESCHED)
return from schedule()
cpu_idle(): preempt_disable();
Window ends here
The interrupts can happen at any point inside the race window. The
first interrupt stops the tick, the second one causes the scheduler to
rerun and switch away from idle again and we end up with the tick
disabled.
The fact that it needs two interrupts where the first one does not set
NEED_RESCHED and the second one does made the bug obscure and extremly
hard to reproduce and analyse. Kudos to Jack and Eric.
Solution: Limit the NOHZ functionality to the idle loop to make sure
that we can not run into such a situation ever again.
cpu_idle()
{
preempt_disable();
while(1) {
tick_nohz_stop_sched_tick(1); <- tell NOHZ code that we
are in the idle loop
while (!need_resched())
halt();
tick_nohz_restart_sched_tick(); <- disables NOHZ mode
preempt_enable_no_resched();
schedule();
preempt_disable();
}
}
In hindsight we should have done this forever, but ...
/me grabs a large brown paperbag.
Debugged-by: Jack Ren <jack.ren@marvell.com>,
Debugged-by: eric miao <eric.y.miao@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Possible RETS Register Corruption when Subroutine Is under 5 Cycles in Duration
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Enable: PM_SUSPEND_MEM -> Blackfin Hibernate to SDRAM
This feature requires a special bootloader (u-boot)
supporting return from hibernate.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
use kernel command line mem and max_mem bootargs to limit
availabe memory instead.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Don't write conflicting data to EBIU_SDBCTL after the SDRAM is
configured. This can cause data corruption, since we might change SDRAM
row and column addressing modes.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
