ARC icache doesn't snoop dcache thus executable pages need to be made
coherent before mapping into userspace in flush_icache_page().
However ARC700 CDU (hardware cache flush module) requires both vaddr
(index in cache) as well as paddr (tag match) to correctly identify a
line in the VIPT cache. A typical ARC700 SoC has aliasing icache, thus
the paddr only based flush_icache_page() API couldn't be implemented
efficiently. It had to loop thru all possible alias indexes and perform
the invalidate operation (ofcourse the cache op would only succeed at
the index(es) where tag matches - typically only 1, but the cost of
visiting all the cache-bins needs to paid nevertheless).
Turns out however that the vaddr (along with paddr) is available in
update_mmu_cache() hence better suits ARC icache flush semantics.
With both vaddr+paddr, exactly one flush operation per line is done.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
munmap ends up calling tlb_flush() which for ARC was flushing the entire
TLB unconditionally (by moving the MMU to a new ASID)
do_munmap
unmap_region
unmap_vmas
unmap_single_vma
unmap_page_range
tlb_start_vma
zap_pud_range
tlb_end_vma()
tlb_finish_mmu
tlb_flush() ---> unconditional flush_tlb_mm()
So even a single page munmap, a frequent operation when uClibc dynamic
linker (ldso) is loading the dependent shared libraries, would move the
the ASID multiple times - needlessly invalidating the pre-faulted TLB
entries (and increasing the rate of ASID wraparound + full TLB flush).
This is now optimised to only be called if tlb->full_mm (which means
for exit/execve) cases only. And for those cases, flush_tlb_mm() is
already optimised to be a no-op for mm->mm_users == 0.
So essentially there are no mmore full mm flushes - except for fork which
anyhow needs it for properly COW'ing parent address space.
munmap now needs to do TLB range flush, which is implemented with
tlb_end_vma()
Results
-------
1. ASID now consistenly moves by 4 during a simple ls (as opposed to 5 or
7 before).
2. LMBench microbenchmark also shows improvements
Basic system parameters
------------------------------------------------------------------------------
Host OS Description Mhz tlb cache mem scal
pages line par load
bytes
--------- ------------- ----------------------- ---- ----- ----- ------ ----
3.9-rc5-0 Linux 3.9.0-r 3.9-rc5-0404-gcc-4.4-ba 80 8 64 1.1000 1
3.9-rc5-0 Linux 3.9.0-r 3.9-rc5-0405-avoid-full 80 8 64 1.1200 1
Processor, Processes - times in microseconds - smaller is better
------------------------------------------------------------------------------
Host OS Mhz null null open slct sig sig fork exec sh
call I/O stat clos TCP inst hndl proc proc proc
--------- ------------- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ----
3.9-rc5-0 Linux 3.9.0-r 80 4.81 8.69 68.6 118. 239. 8.53 31.6 4839 13.K 34.K
3.9-rc5-0 Linux 3.9.0-r 80 4.46 8.36 53.8 91.3 223. 8.12 24.2 4725 13.K 33.K
File & VM system latencies in microseconds - smaller is better
-------------------------------------------------------------------------------
Host OS 0K File 10K File Mmap Prot Page 100fd
Create Delete Create Delete Latency Fault Fault selct
--------- ------------- ------ ------ ------ ------ ------- ----- ------- -----
3.9-rc5-0 Linux 3.9.0-r 314.7 223.2 1054.9 390.2 3615.0 1.590 20.1 126.6
3.9-rc5-0 Linux 3.9.0-r 265.8 183.8 1014.2 314.1 3193.0 6.910 18.8 110.4
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This adds support for an ARC Virtual Platform. This platform is based on the
System C standard promoted by the OSCI (Open System C Initiative) and uses
nSIM to simulate the ARC CPU core itself.
Users can build a virtual SoC by combining System C models of peripherals
and CPU cores.
Signed-off-by: Mischa Jonker <mjonker@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The original device tree was written using a slightly different
implementation of the fixed-factor-clock device tree binding. The
compatible string must be modified in order to be compatible with the
new implementation.
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Infrastructure required to make the Linux kernel compile and boot on the
Abilis Systems TB10x series of SOCs based on ARC700 CPUs:
- Kmake related files (Kconfig, Makefile, tb10x_defconfig)
- TB10x platform initialisation
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
These are the device tree files for the Abilis Systems TB100 and TB101 ICs and
their respective development kit PCBs. These files are committed in preparation
of the following patch set which adds support for these chips to the ARC
platform.
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This patch adds some room for CPU-external interrupt controllers in the
Linux interrupt space. Until now, only the 32 CPU internal interrupt lines
were supported which does not allow for external interrupt controllers such
as GPIO modules etc.
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
arc-intc is initialized in arc common code as it is applicable to all
platforms. However platforms with their own external intc still need to
refer to it for correct DT interrupt tree hierarchy setup,
e.g.
static struct of_device_id __initdata tb10x_irq_ids[] = {
{ .compatible = "snps,arc700-intc", .data = dummy_init_irq },
{ .compatible = "abilis,tb10x_ictl", .data = tb10x_init_irq },
{},
};
The fix is to use the generic irqchip framework to tie all irqchips in
a special linker section and then call irqchip_init() which calls the
DT of_irq_init() for all the intc in one go.
That way the platform code need not be aware of arc-intc at all.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The existing code was wrong on several counts:
* uboot provided bootargs were copied into @boot_command_line, only to
be over-written by setup_machine_fdt(), effectively lost
* @cmdline_p returned by setup_arch() to start_kernel() didn't include
the DT /bootargs
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Given that DeviceTree /bootargs can provide similar functionality,
no point in providing duplicate infrastructure.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The fixup code correctly updates the callee-regs on stack, but
fails to unwind it into actual register file. Thus userspace won't see
the update.
Reported-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
If CONFIG_ARC_MISALIGN_ACCESS is not enabled, or if the fixup fails,
call the same error handler: same signal/si_code to user (SIGBUS)
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
* Remove the line-break between scratch/callee-regs (sneaked in when we
converted from printk to pr_*
* Use %pS to print the symbol names of faulting PC (ret pseudo register)
and BLINK (call return register)
* Don't print user-vma for a kernel crash (only do it for
print-fatal-signals based regfile dump)
* Verbose print the Interrupt/Exception Enable/Active state
* for main executable link address is 0x10000 based (vs. 0) thus offset
of faulting PC needs to be adjusted
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This tracks mainline commit ae903caae2 "Bury the conditionals from
kernel_thread/kernel_execve series" which we missed out as ARC port was
not yet mainline.
[vgupta: commit log modified]
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Currently, for every ARC kernel build I see the following:
--------------->8-----------------
DTB arch/arc/boot/dts/angel4.dtb.S
AS arch/arc/boot/dts/angel4.dtb.o
LD arch/arc/boot/dts/built-in.o
rm arch/arc/boot/dts/angel4.dtb.S <-- forces rebuild next iter
CHK kernel/config_data.h
--------------->8-----------------
This is because *.dts.S is intermediate file in dtb generation and is by
default deleted by make which needs a ".SECONDARY" hint to NOT do so.
This could have ideally been done in scripts/Makefile.lib - for benefit
of all, however .SECONDARY doesn't seem to work with wildcards.
Thanks to Stephen for suggesting .SECONDARY (vs .PRECIOUS) and making
that work using a non wildcard version in arch makefile.
Thanks to James Hogan for pointing out that *.dtb.S now needs to be
added to clean-files
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
commit "fs: make binfmt support for #! scripts modular and removable"
made support for #!scripts optional - thus need to include the Kconfig
file to get all relevant BINFMT_*
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Currently ARC_HAS_LLSC can be influenced by platform for SMP only using
ARC_HAS_COH_LLSC. For !SMP it defaults to "y".
It turns out that some customers can't support it all, even in UP.
So we change the semantics, and use a negative dependency ARC_CANT_LLSC.
Any platform (independent of SMP or !SMP) can select it to disable LLSC.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
arch/arc/kernel/traps.c no longer compiles without explicitly including
asm/kprobes.h
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The existing uImage target always generates gzip compressed image which
drags bootup for some very slow FPGA customer boards.
So introduce seperate make targets:uImage.{bin,gz} with uncompressed
being default. Also tie gz generation to CONFIG_KERNEL_GZIP, which a
platform can select in it's Kconfig if it wishes gz to be default.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
We do cross compiles for ARC Linux.
With gcc 4.7, a make defconfig spews out the following:
------------------->8--------------------------
make ARCH=arc defconfig
gcc: error: unrecognized command line option '-marc600'
gcc: error: unrecognized command line option '-mA7'
gcc: error: unrecognized command line option '-mno-sdata'
gcc: error: unrecognized command line option '-mno-mpy'
*** Default configuration is based on 'fpga_defconfig'
------------------->8--------------------------
This apparently is coming from LIBGCC line - which is strange to be
invoked for defconfig generation.
Reported-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
There's no (Kconfig) macro CONFIG_BLOCK_DEV_RAM. (CONFIG_BLK_DEV_RAM
does exist though.) But linux/blk.h got killed in 2005 anyway (in a
patch titled "kill blk.h"), so these three lines can be removed.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Some header files were included twice in the same file.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Fixes the following coding style issues as detected by checkpatch:
ERROR: space required before the open parenthesis '('
ERROR: "foo * bar" should be "foo *bar"
WARNING: space prohibited between function name and open parenthesis '('
WARNING: please, no spaces at the start of a line
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Silences the following checkpatch warnings:
WARNING: Use #include <linux/ptrace.h> instead of <asm/ptrace.h>
WARNING: Use #include <linux/kprobes.h> instead of <asm/kprobes.h>
WARNING: Use #include <linux/kgdb.h> instead of <asm/kgdb.h>
WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
WARNING: Use #include <linux/cache.h> instead of <asm/cache.h>
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
version.h header file inclusion is not necessary as detected by
versioncheck script.
Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC irqsave/restore macros were missing the compiler barrier, causing a
stale load in irq-enabled region be used in irq-safe region, despite
being changed, because the register holding the value was still live.
The problem manifested as random crashes in timer code when stress
testing ARCLinux (3.9-rc3) on a !SMP && !PREEMPT_COUNT
Here's the exact sequence which caused this:
(0). tv1[x] <----> t1 <---> t2
(1). mod_timer(t1) interrupted after it calls timer_pending()
(2). mod_timer(t2) completes
(3). mod_timer(t1) resumes but messes up the list
(4). __runt_timers( ) uses bogus timer_list entry / crashes in
timer->function
Essentially mod_timer() was racing against itself and while the spinlock
serialized the tv1[] timer link list, timer_pending() called outside the
spinlock, cached timer link list element in a register.
With low register pressure (and a deep register file), lack of barrier
in raw_local_irqsave() as well as preempt_disable (!PREEMPT_COUNT
version), there was nothing to force gcc to reload across the spinlock,
causing a stale value in reg be used for link list manipulation - ensuing
a corruption.
ARcompact disassembly which shows the culprit generated code:
mod_timer:
push_s blink
mov_s r13,r0 # timer, timer
..
###### timer_pending( )
ld_s r3,[r13] # <------ <variable>.entry.next LOADED
brne r3, 0, @.L163
.L163:
..
###### spin_lock_irq( )
lr r5, [status32] # flags
bic r4, r5, 6 # temp, flags,
and.f 0, r5, 6 # flags,
flag.nz r4
###### detach_if_pending( ) begins
tst_s r3,r3 <--------------
# timer_pending( ) checks timer->entry.next
# r3 is NOT reloaded by gcc, using stale value
beq.d @.L169
mov.eq r0,0
##### detach_timer( ): __list_del( )
ld r4,[r13,4] # <variable>.entry.prev, D.31439
st r4,[r3,4] # <variable>.prev, D.31439
st r3,[r4] # <variable>.next, D.30246
We initially tried to fix this by adding barrier() to preempt_* macros
for !PREEMPT_COUNT but Linus clarified that it was anything but wrong.
http://www.spinics.net/lists/kernel/msg1512709.html
[vgupta: updated commitlog]
Reported-by/Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Cc: Christian Ruppert <christian.ruppert@abilis.com>
Cc: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Debugged-by/Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
orig_r8_IS_EXCPN and orig_r8_IS_BRKPT were same values due to a
copy/paste error. Although it looks bad and is wrong, it really doesn't
affect gdb working.
orig_r8_IS_BRKPT is the one relevant to debugging (breakpoints), since
it is used to provide EFA vs. ERET to a ptrace "stop_pc" request.
So when gdb has inserted a breakpoint, orig_r8_IS_BRKPT is already set,
and anything else (i.e. orig_r8_IS_EXCPN) becoming same as it, really
doesn't hurt gdb. The corollary case, could be nasty but nobody uses the
ptrace "stop_pc" request in that case
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
CC drivers/mmc/host/mmc_spi.o
drivers/mmc/host/mmc_spi.c:118: error: redefinition of 'struct scratch'
make[3]: *** [drivers/mmc/host/mmc_spi.o] Error 1
make[2]: *** [drivers/mmc/host] Error 2
make[1]: *** [drivers/mmc] Error 2
make: *** [drivers] Error 2
CC arch/arc/kernel/kgdb.o
In file included from include/linux/kgdb.h:20,
from arch/arc/kernel/kgdb.c:11:
/home/vineetg/arc/k.org/arc-port/arch/arc/include/asm/kgdb.h:34:
warning: 'struct pt_regs' declared inside parameter list
/home/vineetg/arc/k.org/arc-port/arch/arc/include/asm/kgdb.h:34:
warning: its scope is only this definition or declaration, which is
probably not what you want
arch/arc/kernel/kgdb.c:172: error: conflicting types for 'kgdb_trap'
CC arch/arc/kernel/kgdb.o
arch/arc/kernel/kgdb.c: In function 'pt_regs_to_gdb_regs':
arch/arc/kernel/kgdb.c:62: error: dereferencing pointer to incomplete
type
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The upstream kernel ABI (v3) is different from current out-of-tree (v2):
* no-legacy-syscalls
* user_regs_struct layout has changed
So we rev up the ABI version
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ptrace regset interface relies on ELF_NGREG for ceiling the size of user
request. So any larger request (even if legit) would be clipped.
The existing def of ELF_NGREG didn't use user_regs_struct and was
technically one placeholder short (stop_pc) - although the current code
would still work because pt_regs includes a bunch of extra fields,
making
ELF_NGREG >= sizeof(struct user_regs_struct)/sizeof(long)
But we need to remove this ambiguity, specially since pt_regs should NOT
be directly associated with with anything userspace-ish.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The flat DT (currently embedded in vmlinux) is in .init section.
The unflattened/binary tree doesn't copy strings through and references
them from orig flat DT - which could cause catestrohpy if of_* APIs are
called post init, say from a driver which is a loadable module.
Reported-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Syscall restarting fixes made pt_regs->orig_r8 a short word, which was
not reflected in the assembler code - thus could potentially break gdb
debugging.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Commit 0bbacca "hlist: drop the node parameter from iterators" changed
the iterator across the board - but ARC port being out-of-tree missed
it.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The 64bit RTSC is not reliable, causing spurious "jumps" in higher word,
making Linux timekeeping go bonkers. So as of now just use the lower
32bit timestamp.
A cleaner approach would have been removing RTSC support altogether as the
32bit RTSC is equivalent to old TIMER1 based solution, but some customers
can use the 32bit RTSC in SMP syn fashion (vs. TIMER1 which being incore
can't be done easily).
A fallout of this is sched_clock()'s hardware assisted version needs to
go away since it can't use 32bit wrapping counter - instead we use the
generic "weak" jiffies based version.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
!CONFIG_ARC_HAS_(I|D)CACHE makes Linux disable caches (assuming they
exist in hardware) - mostly for debugging issues with new peripherals.
However, independent of CONFIG_ARC_HAS_(I|D)CACHE, Linux also needs to
handle, non-existant caches, using the information in Cache BCRs (Build
Configuration Reg)
Reported-by: Alexey Brodkin <abrodkin@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
