This patch:
- Switches mb/rmb/wmb back to being full-blown DMBs on ARM SMP systems,
since mb/rmb/wmb are required to order Normal memory accesses as well.
- Enables the use of DMB and ISB on XSC3 (which is an ARMv5TE ISA core
but conforms to the ARMv6 memory ordering model and supports the
various ARMv6 barriers.)
- Makes DMA coherent platforms (only ixp23xx at the moment) map
mb/rmb/wmb to dmb(), as on DMA coherent platforms, DMA consistent
mappings are done as Normal mappings, which are weakly ordered.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Currently, the mb() is defined as a DMB operation on ARMv6, even for
UP systems. This patch defines mb() as a compiler barrier only. For
the SMP case, the smp_* variants should be used anyway and the patch
defines them as DMB.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
According to ARM ARM, changes to the CP15 registers are only
guaranteed to be visible after an Instruction Synchronization Barrier
(ISB). This patch adds the ISB at the end of set_cr and
set_copro_access functions and also moves them further down in the
file, below the isb macro definition.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There are three barriers - ISB, DMB and DSB for different
scenarious. This patch adds their definitions in the system.h file.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Move adjust_cr() into arch/arm/mm/mmu.c, and move irqflags.h to
a more appropriate place in the header file.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
i.MX needs to tweak the control register to support CPU frequency
scaling. Rather than have folk blindly try and change the control
register by writing to it and then wondering why it doesn't work,
provide a method (which is safe for UP only, and therefore only
available for UP) to achieve this.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Don't set HWCAP_VFP in the processor support file; not only does it
depend on the processor features, but it also depends on the support
code being present. Therefore, only set it if the support code
detects that we have a VFP coprocessor attached.
Also, move the VFP handling of the coprocessor access register into
the VFP support code.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
All the current CP15 access codes in ARM arch can be categorized and
conditioned by the defines as follows:
Related operation Safe condition
a. any CP15 access !CPU_CP15
b. alignment trap CPU_CP15_MMU
c. D-cache(C-bit) CPU_CP15
d. I-cache CPU_CP15 && !( CPU_ARM610 || CPU_ARM710 ||
CPU_ARM720 || CPU_ARM740 ||
CPU_XSCALE || CPU_XSC3 )
e. alternate vector CPU_CP15 && !CPU_ARM740
f. TTB CPU_CP15_MMU
g. Domain CPU_CP15_MMU
h. FSR/FAR CPU_CP15_MMU
For example, alternate vector is supported if and only if
"CPU_CP15 && !CPU_ARM740" is satisfied.
Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Thomas Gleixner noticed that bitops.h should also use the raw_* irq
disable/enable variants, and __xchg needs them as well.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
set_wmb should not be used in the kernel because it just confuses the
code more and has no benefit. Since it is not currently used in the
kernel this patch removes it so that new code does not include it.
All archs define set_wmb(var, value) to do { var = value; wmb(); }
while(0) except ia64 and sparc which use a mb() instead. But this is
still moot since it is not used anyway.
Hasn't been tested on any archs but x86 and x86_64 (and only compiled
tested)
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Richard Purdie
Add functionality to allow machine specific reboot handlers on ARM.
Add machine specific reboot and poweroff handlers for all PXA Zaurus
models.
Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
The ARM Architecture Reference Manual lists bit 4 of the PMD as "implementation
defined" and it must be set to zero on Intel XScale CPUs or the cache does
not behave properly. Found by Mike Rapoport while debugging a flash issue
on the PXA255:
http://marc.10east.com/?l=linux-arm-kernel&m=114845287600782&w=1
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Patch from Lennert Buytenhek
This patch adds support for the new XScale v3 core. This is an
ARMv5 ISA core with the following additions:
- L2 cache
- I/O coherency support (on select chipsets)
- Low-Locality Reference cache attributes (replaces mini-cache)
- Supersections (v6 compatible)
- 36-bit addressing (v6 compatible)
- Single instruction cache line clean/invalidate
- LRU cache replacement (vs round-robin)
I attempted to merge the XSC3 support into proc-xscale.S, but XSC3
cores have separate errata and have to handle things like L2, so it
is simpler to keep it separate.
L2 cache support is currently a build option because the L2 enable
bit must be set before we enable the MMU and there is no easy way to
capture command line parameters at this point.
There are still optimizations that can be done such as using LLR for
copypage (in theory using the exisiting mini-cache code) but those
can be addressed down the road.
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Patch from Ben Dooks
The enable_hlt and disable_hlt should be declared in
include/asm/setup.h. This fixes sparse errors from
arch/arm/kernel/process.c
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Add per-arch sched_cacheflush() which is a write-back cacheflush used by
the migration-cost calibration code at bootup time.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
In the old days when arm26/arm32 was combined into the same
architecture, proc-fns.h provided the xchg implementation for
arm26 CPUs. Since we no longer combine these two, this include
is no longer required. Remove it.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Convert explicit gcc asm-based memory barriers into smp_mb() calls.
These change between barrier() and the ARMv6 data memory barrier
instruction depending on whether ARMv6 SMP is enabled.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
If we receive an unrecognised abort during boot, don't try to
send a signal to pid0, but instead report the current state.
This leads to less confusing debug reports.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Instead of requiring architecture code to interact with the scheduler's
locking implementation, provide a couple of defines that can be used by the
architecture to request runqueue unlocked context switches, and ask for
interrupts to be enabled over the context switch.
Also replaces the "switch_lock" used by these architectures with an oncpu
flag (note, not a potentially slow bitflag). This eliminates one bus
locked memory operation when context switching, and simplifies the
task_running function.
Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
kernel/sched.c: In function `__might_sleep':
kernel/sched.c:5461: warning: int format, long unsigned int arg (arg 3)
We expect irqs_disabled() to return an int (poor man's bool).
Acked-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We need to re-initialise the stack pointers for undefined, IRQ
and abort mode handlers whenever we resume.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Fix show_regs() to provide a backtrace. Provide a new __show_regs()
function which implements the common subset of show_regs() and die().
Add prototypes to asm-arm/system.h
Signed-off-by: Russell King <rmk@arm.linux.org.uk>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Lennert Buytenhek