Commit Graph

89 Commits

Author SHA1 Message Date
David S. Miller b2d4383480 sparc64: Make PAGE_OFFSET variable.
Choose PAGE_OFFSET dynamically based upon cpu type.

Original UltraSPARC-I (spitfire) chips only supported a 44-bit
virtual address space.

Newer chips (T4 and later) support 52-bit virtual addresses
and up to 47-bits of physical memory space.

Therefore we have to adjust PAGE_SIZE dynamically based upon
the capabilities of the chip.

Note that this change alone does not allow us to support > 43-bit
physical memory, to do that we need to re-arrange our page table
support.  The current encodings of the pmd_t and pgd_t pointers
restricts us to "32 + 11" == 43 bits.

This change can waste quite a bit of memory for the various tables.
In particular, a future change should work to size and allocate
kern_linear_bitmap[] and sparc64_valid_addr_bitmap[] dynamically.
This isn't easy as we really cannot take a TLB miss when accessing
kern_linear_bitmap[].  We'd have to lock it into the TLB or similar.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Bob Picco <bob.picco@oracle.com>
2013-11-12 15:22:34 -08:00
Kirill Tkhai 61d9b9355b sparc64: Remove RWSEM export leftovers
The functions

			__down_read
			__down_read_trylock
			__down_write
			__down_write_trylock
			__up_read
			__up_write
			__downgrade_write

are implemented inline, so remove corresponding EXPORT_SYMBOLs
(They lead to compile errors on RT kernel).

Signed-off-by: Kirill Tkhai <tkhai@yandex.ru>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-09-05 12:12:51 -07:00
Stephen Boyd 446f24d119 Kconfig: consolidate CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
The help text for this config is duplicated across the x86, parisc, and
s390 Kconfig.debug files.  Arnd Bergman noted that the help text was
slightly misleading and should be fixed to state that enabling this
option isn't a problem when using pre 4.4 gcc.

To simplify the rewording, consolidate the text into lib/Kconfig.debug
and modify it there to be more explicit about when you should say N to
this config.

Also, make the text a bit more generic by stating that this option
enables compile time checks so we can cover architectures which emit
warnings vs.  ones which emit errors.  The details of how an
architecture decided to implement the checks isn't as important as the
concept of compile time checking of copy_from_user() calls.

While we're doing this, remove all the copy_from_user_overflow() code
that's duplicated many times and place it into lib/ so that any
architecture supporting this option can get the function for free.

Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30 17:04:09 -07:00
Akinobu Mita 54df2db36c sparc/srmmu: clear trailing edge of bitmap properly
srmmu_nocache_bitmap is cleared by bit_map_init().  But bit_map_init()
attempts to clear by memset(), so it can't clear the trailing edge of
bitmap properly on big-endian architecture if the number of bits is not
a multiple of BITS_PER_LONG.

Actually, the number of bits in srmmu_nocache_bitmap is not always
a multiple of BITS_PER_LONG.  It is calculated as below:

        bitmap_bits = srmmu_nocache_size >> SRMMU_NOCACHE_BITMAP_SHIFT;

srmmu_nocache_size is decided proportionally by the amount of system RAM
and it is rounded to a multiple of PAGE_SIZE.  SRMMU_NOCACHE_BITMAP_SHIFT
is defined as (PAGE_SHIFT - 4).  So it can only be said that bitmap_bits
is a multiple of 16.

This fixes the problem by using bitmap_clear() instead of memset()
in bit_map_init() and this also uses BITS_TO_LONGS() to calculate correct
size at bitmap allocation time.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-03-31 19:29:12 -04:00
David S. Miller 193d2aadc0 sparc: Support atomic64_dec_if_positive properly.
Sparc32 already supported it, as a consequence of using the
generic atomic64 implementation.  And the sparc64 implementation
is rather trivial.

This allows us to set ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE for all
of sparc, and avoid the annoying warning from lib/atomic64_test.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-11-09 19:37:59 -08:00
David S. Miller 9f825962ef sparc64: Niagara-4 bzero/memset, plus use MRU stores in page copy.
This adds optimized memset/bzero/page-clear routines for Niagara-4.

We basically can do what powerpc has been able to do for a decade (via
the "dcbz" instruction), which is use cache line clearing stores for
bzero and memsets with a 'c' argument of zero.

As long as we make the cache initializing store to each 32-byte
subblock of the L2 cache line, it works.

As with other Niagara-4 optimized routines, the key is to make sure to
avoid any usage of the %asi register, as reads and writes to it cost
at least 50 cycles.

For the user clear cases, we don't use these new routines, we use the
Niagara-1 variants instead.  Those have to use %asi in an unavoidable
way.

A Niagara-4 8K page clear costs just under 600 cycles.

Add definitions of the MRU variants of the cache initializing store
ASIs.  By default, cache initializing stores install the line as Least
Recently Used.  If we know we're going to use the data immediately
(which is true for page copies and clears) we can use the Most
Recently Used variant, to decrease the likelyhood of the lines being
evicted before they get used.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-05 13:45:26 -07:00
David S. Miller 954f9ac43b Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux
There's a Niagara 2 memcpy fix in this tree and I have
a Kconfig fix from Dave Jones which requires the sparc-next
changes which went upstream yesterday.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-02 23:02:10 -04:00
David S. Miller 42a4172b6e sparc64: Fix trailing whitespace in NG4 memcpy.
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-28 13:08:22 -07:00
David S. Miller 9019205732 sparc64: Fix comment type in NG4 copy from user.
Noticed by Greg Onufer.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-27 14:26:41 -07:00
David S. Miller 1b62ca7bf5 sparc64: Fix return value of Niagara-2 memcpy.
It gets clobbered by the kernel's VISEntryHalf, so we have to save it
in a different register than the set clobbered by that macro.

The instance in glibc is OK and doesn't have this problem.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-27 01:06:43 -07:00
David S. Miller ae2c6ca641 sparc64: Add SPARC-T4 optimized memcpy.
Before		After
		--------------	--------------
bw_tcp:         1288.53 MB/sec	1637.77 MB/sec
bw_pipe:        1517.18 MB/sec	2107.61 MB/sec
bw_unix:        1838.38 MB/sec	2640.91 MB/sec

make -s -j128
allmodconfig	5min 49sec	5min 31sec

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-09-27 00:35:11 -07:00
David S. Miller 4ff28d4ca9 sparc64: Add SHA1 driver making use of the 'sha1' instruction.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
2012-08-20 15:08:49 -07:00
David S. Miller 6f1d827f29 sparc64: Consistently use fsrc2 rather than fmovd in optimized asm.
Because fsrc2, unlike fmovd, does not update the %fsr register.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-27 01:25:23 -07:00
David Miller 2c66f62363 sparc: use the new generic strnlen_user() function
This throws away the sparc-specific functions in favor of the generic
optimized version.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-26 11:33:54 -07:00
David S. Miller 2922585b93 lib: Sparc's strncpy_from_user is generic enough, move under lib/
To use this, an architecture simply needs to:

1) Provide a user_addr_max() implementation via asm/uaccess.h

2) Add "select GENERIC_STRNCPY_FROM_USER" to their arch Kcnfig

3) Remove the existing strncpy_from_user() implementation and symbol
   exports their architecture had.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: David Howells <dhowells@redhat.com>
2012-05-24 13:12:28 -07:00
David S. Miller 446969084d kernel: Move REPEAT_BYTE definition into linux/kernel.h
And make sure that everything using it explicitly includes
that header file.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-24 13:10:05 -07:00
David S. Miller 35c9646062 sparc: Increase portability of strncpy_from_user() implementation.
Hide details of maximum user address calculation in a new
asm/uaccess.h interface named user_addr_max().

Provide little-endian implementation in find_zero(), which should work
but can probably be improved.

Abstrace alignment check behind IS_UNALIGNED() macro.

Kill double-semicolon, noticed by David Howells.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-24 13:04:24 -07:00
David S. Miller 4efcac3a24 sparc: Optimize strncpy_from_user() zero byte search.
Compute a mask that will only have 0x80 in the bytes which
had a zero in them.  The formula is:

	~(((x & 0x7f7f7f7f) + 0x7f7f7f7f) | x | 0x7f7f7f7f)

In the inner word iteration, we have to compute the "x | 0x7f7f7f7f"
part, so we can reuse that in the above calculation.

Once we have this mask, we perform divide and conquer to find the
highest 0x80 location.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-23 19:20:20 -07:00
David S. Miller ff06dffbc8 sparc: Add full proper error handling to strncpy_from_user().
Linus removed the end-of-address-space hackery from
fs/namei.c:do_getname() so we really have to validate these edge
conditions and cannot cheat any more (as x86 used to as well).

Move to a common C implementation like x86 did.  And if both
src and dst are sufficiently aligned we'll do word at a time
copies and checks as well.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-22 23:32:27 -07:00
David S. Miller 74c7b28953 sparc32: Add ucmpdi2.o to obj-y instead of lib-y.
Otherwise if no references exist in the static kernel image,
we won't export the symbol properly to modules.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-19 15:27:01 -07:00
Sam Ravnborg de36e66d5f sparc32: add ucmpdi2
Based on copy from microblaze add ucmpdi2 implementation.
This fixes build of niu driver which failed with:

drivers/built-in.o: In function `niu_get_nfc':
niu.c:(.text+0x91494): undefined reference to `__ucmpdi2'

This driver will never be used on a sparc32 system,
but patch added to fix build breakage with all*config builds.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-19 15:23:57 -07:00
David S. Miller 1b35a57b1c sparc32: Kill off software 32-bit multiply/divide routines.
For the explicit calls to .udiv/.umul in assembler, I made a
mechanical (read as: safe) transformation.  I didn't attempt
to make any simplifications.

In particular, __ndelay and __udelay can be simplified significantly.
Some of the %y reads are unnecessary and these routines have no need
any longer for allocating a register window, they can be leaf
functions.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-15 11:23:47 -07:00
David S. Miller 73c1377da9 sparc32: Kill btfixup for xchg()'s 'swap' instruction.
We always have this instruction available, so no need to use
btfixup for it any more.

This also eradicates the whole of atomic_32.S and thus the
__atomic_begin and __atomic_end symbols completely.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-13 13:07:16 -07:00
David S. Miller 8695c37d06 sparc: Convert some assembler over to linakge.h's ENTRY/ENDPROC
Use those, instead of doing it all by hand.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-11 20:33:22 -07:00
David S. Miller b55e81b9f8 sparc32: Remove inline strncmp "optimization" for constant counts.
Let the compiler do stuff like this.

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-11 19:53:29 -07:00
Sam Ravnborg 593fc6ea47 sparc32: drop sun4c specific ___xchg32 implementation
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-11 19:27:47 -07:00
David Miller c6df4b17c8 lib: Fix multiple definitions of clz_tab
Both sparc 32-bit's software divide assembler and MPILIB provide
clz_tab[] with identical contents.

Break it out into a seperate object file and select it when
SPARC32 or MPILIB is set.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Morris <jmorris@namei.org>
2012-02-02 10:34:23 +11:00
Linus Torvalds e343a895a9 lib: use generic pci_iomap on all architectures
Many architectures don't want to pull in iomap.c,
 so they ended up duplicating pci_iomap from that file.
 That function isn't trivial, and we are going to modify it
 https://lkml.org/lkml/2011/11/14/183
 so the duplication hurts.
 
 This reduces the scope of the problem significantly,
 by moving pci_iomap to a separate file and
 referencing that from all architectures.
 
 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

lib: use generic pci_iomap on all architectures

Many architectures don't want to pull in iomap.c,
so they ended up duplicating pci_iomap from that file.
That function isn't trivial, and we are going to modify it
https://lkml.org/lkml/2011/11/14/183
so the duplication hurts.

This reduces the scope of the problem significantly,
by moving pci_iomap to a separate file and
referencing that from all architectures.

* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  alpha: drop pci_iomap/pci_iounmap from pci-noop.c
  mn10300: switch to GENERIC_PCI_IOMAP
  mn10300: add missing __iomap markers
  frv: switch to GENERIC_PCI_IOMAP
  tile: switch to GENERIC_PCI_IOMAP
  tile: don't panic on iomap
  sparc: switch to GENERIC_PCI_IOMAP
  sh: switch to GENERIC_PCI_IOMAP
  powerpc: switch to GENERIC_PCI_IOMAP
  parisc: switch to GENERIC_PCI_IOMAP
  mips: switch to GENERIC_PCI_IOMAP
  microblaze: switch to GENERIC_PCI_IOMAP
  arm: switch to GENERIC_PCI_IOMAP
  alpha: switch to GENERIC_PCI_IOMAP
  lib: add GENERIC_PCI_IOMAP
  lib: move GENERIC_IOMAP to lib/Kconfig

Fix up trivial conflicts due to changes nearby in arch/{m68k,score}/Kconfig
2012-01-10 18:04:27 -08:00
Sam Ravnborg 348738afe5 sparc32: drop unused atomic24 support
atomic24 support was used to semaphores in the past - but is no longer used.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-27 14:11:40 -05:00
Michael S. Tsirkin a21a2fd403 sparc: switch to GENERIC_PCI_IOMAP
sparc copied pci_iomap from generic code, probably to avoid
pulling the rest of iomap.c in.  Since that's in
a separate file now, we can reuse the common implementation.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2011-12-04 15:59:49 +02:00
David S. Miller a52312b88c sparc32: Correct the return value of memcpy.
Properly return the original destination buffer pointer.

Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Kjetil Oftedal <oftedal@gmail.com>
2011-10-20 15:17:23 -07:00
David S. Miller 21f74d361d sparc32: Remove uses of %g7 in memcpy implementation.
This is setting things up so that we can correct the return
value, so that it properly returns the original destination
buffer pointer.

Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Kjetil Oftedal <oftedal@gmail.com>
2011-10-20 15:17:22 -07:00
David S. Miller 045b7de9ca sparc32: Remove non-kernel code from memcpy implementation.
Signed-off-by: David S. Miller <davem@davemloft.net>
Tested-by: Kjetil Oftedal <oftedal@gmail.com>
2011-10-20 15:17:22 -07:00
Josip Rodin a61b582954 sparc: Fix __atomic_add_unless() return value.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-04 02:47:40 -07:00
David S. Miller 56d205cc5c sparc: Use popc when possible for ffs/__ffs/ffz.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-02 21:28:53 -07:00
David S. Miller ef7c4d4675 sparc: Use popc if possible for hweight routines.
Just like powerpc, we code patch at boot time.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-02 21:28:50 -07:00
David S. Miller e95ade0839 sparc: Minor tweaks to Niagara page copy/clear.
Don't use floating point on Niagara2, use the traditional
plain Niagara code instead.

Unroll Niagara loops to 128 bytes for copy, and 256 bytes
for clear.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-02 21:28:32 -07:00
Stephen Rothwell 678624e401 sparc: rename atomic_add_unless
Should have been done in commit 1af08a1407f4 ("This is in preparation
for more generic atomic").

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Arun Sharma <asharma@fb.com>
Cc: David Miller <davem@davemloft.net>
Cc: "Hans-Christian Egtvedt" <hans-christian.egtvedt@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-27 12:53:36 -07:00
Arun Sharma 60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:47 -07:00
David S. Miller 9fafbd8061 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6 2011-05-20 12:59:54 -07:00
Tkhai Kirill b1054282d7 sparc32: Fixed unaligned memory copying in function __csum_partial_copy_sparc_generic
When we are in the label cc_dword_align, registers %o0 and %o1 have the same last 2 bits,
but it's not guaranteed one of them is zero. So we can get unaligned memory access
in label ccte. Example of parameters which lead to this:
%o0=0x7ff183e9, %o1=0x8e709e7d, %g1=3

With the parameters I had a memory corruption, when the additional 5 bytes were rewritten.
This patch corrects the error.

One comment to the patch. We don't care about the third bit in %o1, because cc_end_cruft
stores word or less.

Signed-off-by: Tkhai Kirill <tkhai@yandex.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-11 21:35:04 -07:00
Daniel Hellstrom 1827237065 sparc32: removed unused code, implemented by generic code
Signed-off-by: Daniel Hellstrom <daniel@gaisler.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-21 16:44:44 -07:00
Linus Torvalds 0586bed3e8 Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rtmutex: tester: Remove the remaining BKL leftovers
  lockdep/timers: Explain in detail the locking problems del_timer_sync() may cause
  rtmutex: Simplify PI algorithm and make highest prio task get lock
  rwsem: Remove redundant asmregparm annotation
  rwsem: Move duplicate function prototypes to linux/rwsem.h
  rwsem: Unify the duplicate rwsem_is_locked() inlines
  rwsem: Move duplicate init macros and functions to linux/rwsem.h
  rwsem: Move duplicate struct rwsem declaration to linux/rwsem.h
  x86: Cleanup rwsem_count_t typedef
  rwsem: Cleanup includes
  locking: Remove deprecated lock initializers
  cred: Replace deprecated spinlock initialization
  kthread: Replace deprecated spinlock initialization
  xtensa: Replace deprecated spinlock initialization
  um: Replace deprecated spinlock initialization
  sparc: Replace deprecated spinlock initialization
  mips: Replace deprecated spinlock initialization
  cris: Replace deprecated spinlock initialization
  alpha: Replace deprecated spinlock initialization
  rtmutex-tester: Remove BKL tests
2011-03-15 18:28:30 -07:00
Akinobu Mita e637804c33 sparc: use bitmap_set()
Use bitmap_set() instead of calling __set_bit() each bit.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-08 22:52:53 -08:00
Thomas Gleixner 24774fbdea sparc: Replace deprecated spinlock initialization
SPIN_LOCK_UNLOCK is deprecated. Use the lockdep capable variant
instead.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: David S. Miller <davem@davemloft.net>
2011-01-27 12:30:37 +01:00
David S. Miller 0f58189d4a sparc64: Make lock backoff really a NOP on UP builds.
As noticed by Mikulas Patocka, the backoff macros don't
completely nop out for UP builds, we still get a
branch always and a delay slot nop.

Fix this by making the branch to the backoff spin loop
selective, then we can nop out the spin loop completely.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-18 22:53:26 -07:00
Mikulas Patocka 6ec274750c sparc64: simple microoptimizations for atomic functions
Simple microoptimizations for sparc64 atomic functions:
Save one instruction by using a delay slot.
Use %g1 instead of %g7, because %g1 is written earlier.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-18 22:51:08 -07:00
David S. Miller 9b3bb86aca sparc64: Make rwsems 64-bit.
Basically tip-off the powerpc code, use a 64-bit type and atomic64_t
interfaces for the implementation.

This gets us off of the by-hand asm code I wrote, which frankly I
think probably ruins I-cache hit rates.

The idea was the keep the call chains less deep, but anything taking
the rw-semaphores probably is also calling other stuff and therefore
already has allocated a stack-frame.  So no real stack frame savings
ever.

Ben H. has posted patches to make powerpc use 64-bit too and with some
abstractions we can probably use a shared header file somewhere.

With suggestions from Sam Ravnborg.

Signed-off-by: David S. Miller <davem@davemloft.net>
2010-08-17 22:49:26 -07:00
David S. Miller 035df35d96 sparc64: Allocate sufficient stack space in ftrace stubs.
128 bytes is sufficient for the register window save area, but the
calling conventions allow the callee to save up to 6 incoming argument
registers into the stack frame after the register window save area.

This means a minimal stack frame is 176 bytes (128 + (6 * 8)).

This fixes random crashes when using the function tracer.

Reported-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-13 18:59:02 -07:00
David S. Miller 9960e9e894 sparc64: Add function graph tracer support.
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-12 22:37:26 -07:00