Commit Graph

56 Commits

Author SHA1 Message Date
Alan Modra c153693d7e powerpc: Simplify module TOC handling
PowerPC64 uses the symbol .TOC. much as other targets use
_GLOBAL_OFFSET_TABLE_. It identifies the value of the GOT pointer (or in
powerpc parlance, the TOC pointer). Global offset tables are generally
local to an executable or shared library, or in the kernel, module. Thus
it does not make sense for a module to resolve a relocation against
.TOC. to the kernel's .TOC. value. A module has its own .TOC., and
indeed the powerpc64 module relocation processing ignores the kernel
value of .TOC. and instead calculates a module-local value.

This patch removes code involved in exporting the kernel .TOC., tweaks
modpost to ignore an undefined .TOC., and the module loader to twiddle
the section symbol so that .TOC. isn't seen as undefined.

Note that if the kernel was compiled with -msingle-pic-base then ELFv2
would not have function global entry code setting up r2. In that case
the module call stubs would need to be modified to set up r2 using the
kernel .TOC. value, requiring some of this code to be reinstated.

mpe: Furthermore a change in binutils master (not yet released) causes
the current way we handle the TOC to no longer work when building with
MODVERSIONS=y and RELOCATABLE=n. The symptom is that modules can not be
loaded due to there being no version found for TOC.

Cc: stable@vger.kernel.org # 3.16+
Signed-off-by: Alan Modra <amodra@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2016-01-21 14:10:56 +11:00
Tiejun Chen 96eea6426f powerpc/book3e-64: Enable kexec
Allow KEXEC for book3e, and bypass or convert non-book3e stuff
in kexec code.

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
[scottwood@freescale.com: move code to minimize diff, and cleanup]
Signed-off-by: Scott Wood <scottwood@freescale.com>
2015-10-27 18:13:30 -05:00
Scott Wood ae73e4ccbc powerpc/book3e-64/kexec: Set "r4 = 0" when entering spinloop
book3e_secondary_core_init will only create a TLB entry if r4 = 0,
so do so.

Signed-off-by: Scott Wood <scottwood@freescale.com>
2015-10-27 18:13:30 -05:00
Tiejun Chen cf904e3088 powerpc/book3e-64/kexec: create an identity TLB mapping
book3e has no real MMU mode so we have to create an identity TLB
mapping to make sure we can access the real physical address.

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
[scottwood: cleanup, and split off some changes]
Signed-off-by: Scott Wood <scottwood@freescale.com>
2015-10-27 18:13:28 -05:00
Samuel Mendoza-Jonas ffebf5f391 powerpc/kexec: Reset secondary cpu endianness before kexec
If the target kernel does not inlcude the FIXUP_ENDIAN check, coming
from a different-endian kernel will cause the target kernel to panic.
All ppc64 kernels can handle starting in big-endian mode, so return to
big-endian before branching into the target kernel.

This mainly affects pseries as secondaries on powernv are returned to
OPAL.

Signed-off-by: Samuel Mendoza-Jonas <sam.mj@au1.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2015-08-20 18:19:08 +10:00
Rusty Russell 71ec7c55ed powerpc: module: handle MODVERSION for .TOC.
For the ELFv2 ABI, powerpc introduces a magic symbol ".TOC.".  If we
don't create a CRC for it (minus the leading ".", since we strip that)
we get a modpost warning about missing CRC and the CRC array seems to
be displaced by 1 so other CRCs mismatch too.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-04-23 10:05:28 +10:00
Rusty Russell 9baeaef640 powerpc: EXPORT_SYMBOL(.TOC.)
For the ELFv2 ABI, powerpc introduces a magic symbol ".TOC.".  depmod
then complains that this doesn't resolve (so does modpost, but we could
easily fix that).  To export this, we need to use asm.

modpost and depmod both strip "." from symbols for the old PPC64 ELFv1
ABI, so we actually export a "TOC.".

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-04-23 10:05:28 +10:00
Anton Blanchard cc7efbf919 powerpc: ABIv2 function calls must place target address in r12
To establish addressability quickly, ABIv2 requires the target
address of the function being called to be in r12. Fix a number of
places in assembly code that we do indirect function calls.

We need to avoid function descriptors on ABIv2 too.

Signed-off-by: Anton Blanchard <anton@samba.org>
2014-04-23 10:05:20 +10:00
Anton Blanchard b1576fec7f powerpc: No need to use dot symbols when branching to a function
binutils is smart enough to know that a branch to a function
descriptor is actually a branch to the functions text address.

Alan tells me that binutils has been doing this for 9 years.

Signed-off-by: Anton Blanchard <anton@samba.org>
2014-04-23 10:05:16 +10:00
Benjamin Herrenschmidt dece8ada99 Merge branch 'merge' into next
Merge a pile of fixes that went into the "merge" branch (3.13-rc's) such
as Anton Little Endian fixes.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-30 15:19:31 +11:00
Michael Ellerman 2d6f0c3ae6 powerpc: Fix build break with PPC_EARLY_DEBUG_BOOTX=y
A kernel configured with PPC_EARLY_DEBUG_BOOTX=y but PPC_PMAC=n and
PPC_MAPLE=n will fail to link:

  btext.c:(.text+0x2d0fc): undefined reference to `.rmci_off'
  btext.c:(.text+0x2d214): undefined reference to `.rmci_on'

Fix it by making the build of rmci_on/off() depend on
PPC_EARLY_DEBUG_BOOTX, which also enable the only code that uses them.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-10 11:25:03 +11:00
Kevin Hao 0ce636700c powerpc: purge all the prefetched instructions for the coherent icache flush
As Benjamin Herrenschmidt has indicated, we still need a dummy icbi to
purge all the prefetched instructions from the ifetch buffers for the
snooping icache. We also need a sync before the icbi to order the
actual stores to memory that might have modified instructions with
the icbi.

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-12-02 14:13:47 +11:00
Benjamin Herrenschmidt 0366a1c70b powerpc/irq: Run softirqs off the top of the irq stack
Nowadays, irq_exit() calls __do_softirq() pretty much directly
instead of calling do_softirq() which switches to the decicated
softirq stack.

This has lead to observed stack overflows on powerpc since we call
irq_enter() and irq_exit() outside of the scope that switches to
the irq stack.

This fixes it by moving the stack switching up a level, making
irq_enter() and irq_exit() run off the irq stack.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-09-25 14:15:36 +10:00
Kevin Hao 6ef94ff2e8 powerpc: remove the unused function disable_kernel_fp()
The only using of function disable_kernel_fp() was already dropped
in the commit 5daf9071 (powerpc: merge align.c).

Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-08-14 14:59:25 +10:00
Benjamin Herrenschmidt 7191b61575 powerpc/pmac: Early debug output on screen on 64-bit macs
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>
2013-08-14 14:57:40 +10:00
Kevin Hao 3b04c30007 powerpc: Remove the symbol __flush_icache_range
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>
2013-08-14 14:56:44 +10:00
Kevin Hao abb29c3bb1 powerpc: Move the testing of CPU_FTR_COHERENT_ICACHE into __flush_icache_range
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>
2013-08-14 14:56:06 +10:00
David Woodhouse ca9d7aea59 powerpc: Provide __bswapdi2
Some versions of GCC apparently expect this to be provided by libgcc.

Updates from Mikey to fix 32 bit version and adding "r" to registers.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-05-14 16:00:17 +10:00
Al Viro 58254e1002 powerpc: split ret_from_fork
... and get rid of in-kernel syscalls in kernel_thread()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-30 23:31:19 -04:00
Michael Neuling e55174e911 powerpc: Fixes for instructions not using correct register naming
These macros are using integers where they could be using logical
names since they take registers.

We are going to enforce this soon, so fix these up now.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-07-10 19:18:16 +10:00
Michael Neuling 4404a9f98f powerpc/pasemi: Move lbz/stbciz to ppc-opcode.h
move lbz/stbciz to ppc-opcode.h.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-07-10 19:18:00 +10:00
Michael Neuling c75df6f96c powerpc: Fix usage of register macros getting ready for %r0 change
Anything that uses a constructed instruction (ie. from ppc-opcode.h),
need to use the new R0 macro, as %r0 is not going to work.

Also convert usages of macros where we are just determining an offset
(usually for a load/store), like:
	std	r14,STK_REG(r14)(r1)
Can't use STK_REG(r14) as %r14 doesn't work in the STK_REG macro since
it's just calculating an offset.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2012-07-10 19:17:55 +10:00
Dmitry Eremin-Solenikov e48f7eb27f powerpc/maple: Enable scom access functions on Maple
Enable functions used to access SCOM if PPC_MAPLE is defined: they are
used by cpufreq driver to control hardware.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-06-29 17:48:20 +10:00
Milton Miller 3d2cea732d powerpc/kexec: Fix memory corruption from unallocated slaves
Commit 1fc711f7ff (powerpc/kexec: Fix race
in kexec shutdown) moved the write to signal the cpu had exited the kernel
from before the transition to real mode in kexec_smp_wait to kexec_wait.

Unfornately it missed that kexec_wait is used both by cpus leaving the
kernel and by secondary slave cpus that were not allocated a paca for
what ever reason -- they could be beyond nr_cpus or not described in
the current device tree for whatever reason (for example, kexec-load
was not refreshed after a cpu hotplug operation).  Cpus coming through
that path they will write to paca[NR_CPUS] which is beyond the space
allocated for the paca data and overwrite memory not allocated to pacas
but very likely still real mode accessable).

Move the write back to kexec_smp_wait, which is used only by cpus that
found their paca, but after the transition to real mode.

Signed-off-by: Milton Miller <miltonm@bga.com>
Cc: <stable@kernel.org> # (1fc711f was backported to 2.6.32)
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-05-19 14:30:43 +10:00
Stephen Rothwell 46f5221049 powerpc: Remove second definition of STACK_FRAME_OVERHEAD
Since STACK_FRAME_OVERHEAD is defined in asm/ptrace.h and that
is ASSEMBER safe, we can just include that instead of going via
asm-offsets.h.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-11-29 15:48:23 +11:00
Christoph Hellwig f1ba9a5b2a powerpc: Unconditionally enabled irq stacks
Irq stacks provide an essential protection from stack overflows through
external interrupts, at the cost of two additionals stacks per CPU.

Enable them unconditionally to simplify the kernel build and prevent
people from accidentally disabling them.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-06-15 15:02:37 +10:00
Michael Neuling 1fc711f7ff powerpc/kexec: Fix race in kexec shutdown
In kexec_prepare_cpus, the primary CPU IPIs the secondary CPUs to
kexec_smp_down().  kexec_smp_down() calls kexec_smp_wait() which sets
the hw_cpu_id() to -1.  The primary does this while leaving IRQs on
which means the primary can take a timer interrupt which can lead to
the IPIing one of the secondary CPUs (say, for a scheduler re-balance)
but since the secondary CPU now has a hw_cpu_id = -1, we IPI CPU
-1... Kaboom!

We are hitting this case regularly on POWER7 machines.

There is also a second race, where the primary will tear down the MMU
mappings before knowing the secondaries have entered real mode.

Also, the secondaries are clearing out any pending IPIs before
guaranteeing that no more will be received.

This changes kexec_prepare_cpus() so that we turn off IRQs in the
primary CPU much earlier.  It adds a paca flag to say that the
secondaries have entered the kexec_smp_down() IPI and turned off IRQs,
rather than overloading hw_cpu_id with -1.  This new paca flag is
again used to in indicate when the secondaries has entered real mode.

It also ensures that all CPUs have their IRQs off before we clear out
any pending IPI requests (in kexec_cpu_down()) to ensure there are no
trailing IPIs left unacknowledged.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2010-05-21 17:31:11 +10:00
Benjamin Herrenschmidt e821ea70f3 powerpc: Move VMX and VSX asm code to vector.S
Currently, load_up_altivec and give_up_altivec are duplicated
in 32-bit and 64-bit. This creates a common implementation that
is moved away from head_32.S, head_64.S and misc_64.S and into
vector.S, using the same macros we already use for our common
implementation of load_up_fpu.

I also moved the VSX code over to vector.S though in that case
I didn't make it build on 32-bit (yet).

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-06-09 16:46:25 +10:00
Michael Neuling 7e875e9dc8 powerpc: Disable VSX or current process in giveup_fpu/altivec
When we call giveup_fpu, we need to need to turn off VSX for the
current process.  If we don't, on return to userspace it may execute a
VSX instruction before the next FP instruction, and not have its
register state refreshed correctly from the thread_struct.  Ditto for
altivec.

This caused a bug where an unaligned lfs or stfs results in
fix_alignment calling giveup_fpu so it can use the FPRs (in order to
do a single <-> double conversion), and then returning to userspace
with FP off but VSX on.  Then if a VSX instruction is executed, before
another FP instruction, it will proceed without another exception and
hence have the incorrect register state for VSX registers 0-31.

   lfs unaligned   <- alignment exception turns FP off but leaves VSX on

   VSX instruction <- no exception since VSX on, hence we get the
                      wrong VSX register values for VSX registers 0-31,
                      which overlap the FPRs.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-04-07 15:18:59 +10:00
Milton Miller 1767c8f392 powerpc: Kexec exit should not use magic numbers
Commit 54622f10a6 ("powerpc: Support for
relocatable kdump kernel") added a magic flag value in a register to
tell purgatory that it should be a panic kernel.  This part is wrong
and is reverted by this commit.

The kernel gets a list of memory blocks and a entry point from user space.
Its job is to copy the blocks into place and then branch to the designated
entry point (after turning "off" the mmu).

The user space tool inserts a trampoline, called purgatory, that runs
before the user supplied code.   Its job is to establish the entry
environment for the new kernel or other application based on the contents
of memory.  The purgatory code is compiled and embedded in the tool,
where it is later patched using the elf symbol table using elf symbols.

Since the tool knows it is creating a purgatory that will run after a
kernel crash, it should just patch purgatory (or the kernel directly)
if something needs to happen.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-10-31 16:11:44 +11:00
Mohan Kumar M 54622f10a6 powerpc: Support for relocatable kdump kernel
This adds relocatable kernel support for kdump. With this one can
use the same regular kernel to capture the kdump. A signature (0xfeed1234)
is passed in r6 from panic code to the next kernel through kexec_sequence
and purgatory code. The signature is used to differentiate between
kdump kernel and non-kdump kernels.

The purgatory code compares the signature and sets the __kdump_flag in
head_64.S.  During the boot up, kernel code checks __kdump_flag and if it
is set, the kernel will behave as relocatable kdump kernel. This kernel
will boot at the address where it was loaded by kexec-tools ie. at the
address reserved through crashkernel boot parameter.

CONFIG_CRASH_DUMP depends on CONFIG_RELOCATABLE option to build kdump
kernel as relocatable. So the same kernel can be used as production and
kdump kernel.

This patch incorporates the changes suggested by Paul Mackerras to avoid
GOT use and to avoid two copies of the code.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Mohan Kumar M <mohan@in.ibm.com>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-22 15:01:22 +11:00
Josh Poimboeuf 41c2e949cb powerpc: Fix error path in kernel_thread function
The powerpc 32-bit and 64-bit kernel_thread functions don't properly
propagate errors being returned by the clone syscall.  (In the case of
error, the syscall exit code returns a positive errno in r3 and sets
the CR0[SO] bit.)

This patch fixes that by negating r3 if CR0[SO] is set after the syscall.

Signed-off-by: Josh Poimboeuf <jpoimboe@us.ibm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-10 15:55:18 +11:00
Michael Neuling 7c29217096 powerpc: fix giveup_vsx to save registers correctly
giveup_vsx didn't save the FPU and VMX regsiters.  Change it to be
like giveup_fpr/altivec which save these registers.

Also update call sites where FPU and VMX are already saved to use the
original giveup_vsx (renamed to __giveup_vsx).

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-07-15 12:29:23 +10:00
Michael Neuling ce48b21007 powerpc: Add VSX context save/restore, ptrace and signal support
This patch extends the floating point save and restore code to use the
VSX load/stores when VSX is available.  This will make FP context
save/restore marginally slower on FP only code, when VSX is available,
as it has to load/store 128bits rather than just 64bits.

Mixing FP, VMX and VSX code will get constant architected state.

The signals interface is extended to enable access to VSR 0-31
doubleword 1 after discussions with tool chain maintainers.  Backward
compatibility is maintained.

The ptrace interface is also extended to allow access to VSR 0-31 full
registers.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-01 11:28:50 +10:00
Kumar Gala 4ae2dcb633 [POWERPC] Clean up misc_64.S
* Removed get_msr(), get_srr0(), and get_srr1() - not used anywhere
* Use STACK_FRAME_OVERHEAD instead of magic number

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-04-24 20:58:03 +10:00
Stephen Rothwell 94b146ceee [POWERPC] kernel_execve is identical in 32 and 64 bit
so consolidate it into misc.S.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-12-11 13:34:39 +11:00
Milton Miller ee46a90b59 [POWERPC] kexec: Send slaves to new kernel earlier
With this, when kexec-ing, we copy the code and start the slaves on
their journey to the next kernel's spin loop as soon as we copy the
kexec image into place.

The kernel doesn't know exactly which slaves are spinning in
kexec_wait.  This allows us to pass more than max-cpus to the
next kernel.  But it also means that we might leave some behind.

Moving the code here means they have the time it takes us to
clear the hash table to wake up and move on.  Moving the code
any earlier would reuqire walking the image description to
search for the code, which could span multiple pages.

Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-25 16:55:16 +10:00
Olof Johansson 39c870d5b5 [POWERPC] pasemi: UART udbg support
Early debug output for PA Semi UART. Uses the 2.05 CI real mode ops.

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-02-07 14:03:22 +11:00
Benjamin Herrenschmidt 42c4aaadb7 [POWERPC] Consolidate feature fixup code
There are currently two versions of the functions for applying the
feature fixups, one for CPU features and one for firmware features. In
addition, they are both in assembly and with separate implementations
for 32 and 64 bits. identify_cpu() is also implemented in assembly and
separately for 32 and 64 bits.

This patch replaces them with a pair of C functions. The call sites are
slightly moved on ppc64 as well to be called from C instead of from
assembly, though it's a very small change, and thus shouldn't cause any
problem.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-10-25 11:42:10 +10:00
David Howells 7d12e780e0 IRQ: Maintain regs pointer globally rather than passing to IRQ handlers
Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.

Signed-Off-By: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 15:10:12 +01:00
Paul Mackerras c730f5b621 Merge branch 'master' of git://oak/home/sfr/kernels/iseries/work 2006-10-04 15:02:27 +10:00
Stephen Rothwell 3f639ee8c5 [POWERPC] implement BEGIN/END_FW_FTR_SECTION
and use it an all the obvious places in assembler code.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
2006-10-03 16:50:21 +10:00
Arnd Bergmann 3db03b4afb [PATCH] rename the provided execve functions to kernel_execve
Some architectures provide an execve function that does not set errno, but
instead returns the result code directly.  Rename these to kernel_execve to
get the right semantics there.  Moreover, there is no reasone for any of these
architectures to still provide __KERNEL_SYSCALLS__ or _syscallN macros, so
remove these right away.

[akpm@osdl.org: build fix]
[bunk@stusta.de: build fix]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andi Kleen <ak@muc.de>
Acked-by: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-02 07:57:23 -07:00
Geoff Levand 8d950cb889 [POWERPC] Minor comment fix for misc_64.S
A minor comment fix for misc_64.S from Takao Shinohara.

Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-07-31 14:37:46 +10:00
Benjamin Herrenschmidt b9e5b4e6a9 [POWERPC] Use the genirq framework
This adapts the generic powerpc interrupt handling code, and all of
the platforms except for the embedded 6xx machines, to use the new
genirq framework.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-07-03 19:55:12 +10:00
Jörn Engel 6ab3d5624e Remove obsolete #include <linux/config.h>
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-30 19:25:36 +02:00
Stephen Rothwell 127efeb286 [POWERPC] Consolidate some of kernel/misc*.S
There were some common functions (mainly i/o).

Also some small white space cleanups and remove a couple of small unused
functions.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-28 15:19:00 +10:00
Stephen Rothwell a240da35a1 [POWERPC] Remove unused function call_with_mmu_off
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-28 15:18:58 +10:00
Geoff Levand b26f100d89 [PATCH] powerpc: remove do-nothing cpu setup routines
Removed the do-nothing routines __setup_cpu_power3 and
__setup_cpu_power4 and replaced them with a null pointer check
in the caller.  Also removed the Cell processor specific
routine __setup_cpu_be which improperly accessed the
hypervisor page size configuration at SPR HID6.

Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-05-19 14:24:18 +10:00
David Gibson e58c3495e6 [PATCH] powerpc: Cleanup LOADADDR etc. asm macros
This patch consolidates the variety of macros used for loading 32 or
64-bit constants in assembler (LOADADDR, LOADBASE, SET_REG_TO_*).  The
idea is to make the set of macros consistent across 32 and 64 bit and
to make it more obvious which is the appropriate one to use in a given
situation.  The new macros and their semantics are described in the
comments in ppc_asm.h.

In the process, we change several places that were unnecessarily using
immediate loads on ppc64 to use the GOT/TOC.  Likewise we cleanup a
couple of places where we were clumsily subtracting PAGE_OFFSET with
asm instructions to use assemble-time arithmetic or the toreal() macro
instead.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-13 21:16:23 +11:00