We need it saved because it contains a3 where we track which register
windows we still need to spill, and fixup handler may call C exception
handlers. Also fix comments.

Cc: stable@vger.kernel.org
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>

Most in-kernel users want registers spilled on the kernel stack and
don't require PS.EXCM to be set. That means that they don't need fixup
routine and could reuse regular window overflow mechanism for that,
which makes spill routine very simple.

Cc: stable@vger.kernel.org
Suggested-by: NChris Zankel <chris@zankel.net>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>

Now that ccount_freq is used in udelay and ndelay it needs to be
exported in order to be available to modules.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>

Use the simple-bus node to discover the io area, and remap the cached and
bypass io ranges. The parent-bus-address value of the first triplet in the
"ranges" property is used. This value is rounded down to the nearest 256MB
boundary. The length of the io area is fixed at 256MB; the "ranges" property
length value is ignored.

Other limitations: (1) only the first simple-bus node is considered, and (2)
only the first triplet of the "ranges" property is considered.

See ePAPR 1.1 §6.5 for the simple-bus node description, and §2.3.8 for the
"ranges" property description.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>

This currently includes simple-bus.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>

Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>

there is a small possibility that wake_up of softirq thread
happens between local_irq_enable() and set_cpu_online(). In
this case affinity of the thread changes to fallback affinity
(i.e. CPU0). This may be a source of problems.

The patch kills that possibility.
Signed-off-by: NKirill Tkhai <tkhai@yandex.ru>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>

The 32 bit sched_clock interface now supports 64 bits. Upgrade
to the 64 bit function to allow us to remove the 32 bit
registration interface.
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Acked-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

This is largely based on SMP code from the xtensa-2.6.29-smp tree by
Piet Delaney, Marc Gauthier, Joe Taylor, Christian Zankel (and possibly
other Tensilica folks).
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

MX is an interrupt distributor used in some SMP-capable xtensa
configurations.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

PIC irq_ack doesn't clear timer IRQ, because timer interrupt handler
usually set up new timer by writing to ccompare register and thus
clearing timer IRQ. However timer may not be set up in the IRQ handler,
e.g. with tickless idle on SMP, or when CPU is going offline, leaving
timer IRQ raised and making do_interrupt attempting to handle it
forever.

To fix this always write current value of ccompare SR chosen to be linux
timer back to that SR on entry to timer interrupt handler.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

- set up irq registers and call irq_enter/irq_exit once for each kernel
  entry due to interrupt;
- don't attempt to clear current IRQ in the do_interrupt, IRQ handler
  will take care of it;
- find pending interrupt with highest priority before every ISR
  invocation.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Extract xtensa built-in interrupt controller implementation from
xtensa/kernel/irq.c and move it to other irqchips, providing way to
instantiate it from the device tree.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Secondary CPUs need this declaration to initialize their MMUs.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Otherwise exceptions may occur prior to exception handling mechanism
initialization, resulting in silently dead system.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Provide per-cpu ccount_timer objects and use them appropriately.
Extract per-cpu clockevent setup function.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

This allows ccount to be used as highres timer.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

According to create_thread(3): "The new thread does not inherit the creating
thread's alternate signal stack". Since commit f9a3879a (Fix sigaltstack
corruption among cloned threads), current->sas_ss_size is set to 0 for cloned
processes sharing VM with their parent. Don't use the (nonexistent) alternate
signal stack in this case. This has been broken since commit 29c4dfd9 ([XTENSA]
Remove non-rt signal handling).

Fixes the SA_ONSTACK part of the nptl/tst-cancel20 test from uClibc.

Cc: <stable@vger.kernel.org>
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

fast_syscall_spill_registers_fixup was not correctly updated by the
'keep a3 and excsave1 on entry to exception handlers' patch: it doesn't
preserve a3 that it gets on entry, breaking _spill_registers in case of
page fault on stack during register spilling, leading to unhandled
exception in kernel mode.

Preserve a3 by saving it in the original _spill_registers stack frame's
a3 during exception handling and restoring it afterwards.

Also fix comments and function bounds annotations.
Reported-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Tested-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NChris Zankel <chris@zankel.net>

All arches do essentially the same thing now for
early_init_dt_setup_initrd_arch, so it can now be removed.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Mark Salter <msalter@redhat.com>
Cc: Aurelien Jacquiot <a-jacquiot@ti.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Acked-by: NGrant Likely <grant.likely@linaro.org>

Convert xtensa to use new early_init_dt_scan function.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NMax Filippov <jcmvbkbc@gmail.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: linux-xtensa@linux-xtensa.org

Use the common unflatten_and_copy_device_tree to copy the built-in FDT
out of init section.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: NMax Filippov <jcmvbkbc@gmail.com>
Cc: linux-xtensa@linux-xtensa.org
Acked-by: NGrant Likely <grant.likely@linaro.org>

xtansa allmodbuild fails with:

arch/xtensa/kernel/xtensa_ksyms.c:129:1: error: '_mcount' undeclared here (not in a function)
make[2]: *** [arch/xtensa/kernel/xtensa_ksyms.o] Error 1
make[1]: *** [arch/xtensa/kernel] Error 2

The breakage is due to commit 478ba61a (xtensa: add static function tracer
support) which exports _mcount without declaring it.

Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NChris Zankel <chris@zankel.net>

Use ccount_freq directly to make the code a little more readable.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Commits 925f5532 (xtensa: ccount based clockevent implementation) and e3f43291
(xtensa: ccount based sched_clock) introduced users of ccount_freq. This
variable doesn't exist when CONFIG_XTENSA_CALIBRATE_CCOUNT is disabled. Add
ccount_freq definition in this case.
Reported-by: NChen Gang <gang.chen@asianux.com>
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Instead of emulating movsp instruction in the kernel use window
underflow handler to load missing register window and retry failed
movsp.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Based on the SMP patch by Joe Taylor and subsequent fixes.
Preserve exception table pointer (normally stored in excsave1 SR) as it
cannot be easily restored in SMP environment.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Check pending signals and rescheduling thread flags with interrupts
disabled, and don't enable them if no flags are set. Call
trace_hardirqs_on after thread flags handling, so that rescheduling is
done and hardirqs tracking flag is updated in the correct task context.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

On some PAE architectures, the entire range of physical memory could reside
outside the 32-bit limit.  These systems need the ability to specify the
initrd location using 64-bit numbers.

This patch globally modifies the early_init_dt_setup_initrd_arch() function to
use 64-bit numbers instead of the current unsigned long.

There has been quite a bit of debate about whether to use u64 or phys_addr_t.
It was concluded to stick to u64 to be consistent with rest of the device
tree code. As summarized by Geert, "The address to load the initrd is decided
by the bootloader/user and set at that point later in time. The dtb should not
be tied to the kernel you are booting"

More details on the discussion can be found here:
https://lkml.org/lkml/2013/6/20/690
https://lkml.org/lkml/2012/9/13/544Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NRob Herring <rob.herring@calxeda.com>
Acked-by: NVineet Gupta <vgupta@synopsys.com>
Acked-by: NJean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications.  For example, the fix in
commit 5e427ec2 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.

After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out.  Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.

Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit  -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings.  In any case, they are temporary and harmless.

This removes all the arch/xtensa uses of the __cpuinit macros from
all C files.  Currently xtensa does not have any __CPUINIT used in
assembly files.

[1] https://lkml.org/lkml/2013/5/20/589

Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: linux-xtensa@linux-xtensa.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

flat DT copy code calls bootmem allocator with @align = 0.
This is probably OK with legacy allocator which xtensa uses right now,
but this will panic right away with memblock allocator
Signed-off-by: NVineet Gupta <vgupta@synopsys.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Marc Gauthier <marc@tensilica.com>
Cc: linux-xtensa@linux-xtensa.org
Cc: linux-kernel@vger.kernel.org
Acked-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

- check that user TLB mappings correspond to the current page table;
- check that TLB mapping VPN is in the kernel/user address range
  in accordance with its ASID.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

The virtual address of boot parameters chain is passed to the kernel via
a2 register. Adjust it in case it is remapped during MMUv3 -> MMUv2
mapping change, i.e. when it is in the first 128M.

Also fix interpretation of initrd and FDT addresses passed in the boot
parameters: these are physical addresses.

Cc: stable@vger.kernel.org
Reported-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>

Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NChris Zankel <chris@zankel.net>

Reused some code from a preliminary implementation by Max Fillippov.

Cc: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NChris Zankel <chris@zankel.net>

Remove unused nsec_per_ccount, and rename ccount_per_jiffy to ccount_preq.
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Signed-off-by: NChris Zankel <chris@zankel.net>

Remove __init annotation from pcibios_fixup_bus as is called from
pci_scan_child_bus which is not __init.

Also fix a couple of minor build warnings.
Signed-off-by: NMax Filippov <jcmvbkbc@gmail.com>
Signed-off-by: NChris Zankel <chris@zankel.net>