linux.git/arch/frv, branch v2.6.25

FRV: Correctly determine the address of an illegal instruction

2008-04-14T14:55:15+00:00

Correctly determine the address of an illegal instruction.  The EPCR0 register
holds this value (masked by EPCR0_PC) if the validity bit is set (masked by
EPCR0_V).  So the test as to whether the contents of the register are usable
should be involve checking the _V bit, not the _PC bits.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

FRV: Make NOMMU-mode work with base addresses other than 0xC0000000 [try #2]

2008-04-10T20:41:29+00:00

Make NOMMU-mode work with base addresses other than 0xC0000000 by:

 (1) Giving the code that sets up the protection registers the right address
     in __sdram_base.  Rather than being hard coded to 0xC0000000, the value
     of __page_offset is obtained from the linker script.

 (2) Eliminate the check in __switch_to() that verifies the current thread
     info is in the 0xCxxxxxxx region.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

FRV: Add support for emulation of userspace atomic ops [try #2]

2008-04-10T20:41:29+00:00

Use traps 120-126 to emulate atomic cmpxchg32, xchg32, and XOR-, OR-, AND-, SUB-
and ADD-to-memory operations for userspace.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

FRV: Change the timerfd syscalls to be the same as i386

2008-02-21T03:58:16+00:00

Change the FRV timerfd syscalls to be the same as i386 timerfd syscalls.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

FRV: Drop the .data.idt section for FRV

2008-02-21T03:58:16+00:00

There is no .data.idt section for FRV, so drop it from the linker script.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

xtime_lock vs update_process_times

2008-02-13T21:29:25+00:00

Commit d3d74453c34f8fd87674a8cf5b8a327c68f22e99 ("hrtimer: fixup the
HRTIMER_CB_IRQSAFE_NO_SOFTIRQ fallback") broke several archs, and since
only Russell bothered to merge the fix, and Greg to ACK his arch, I'm
sending this for merger.

I have confirmation that the Alpha bit results in a booting kernel.
That leaves: blackfin, frv, sh and sparc untested.

The deadlock in question was found by Russell:

  IRQ handle
    -> timer_tick() - xtime seqlock held for write
      -> update_process_times()
        -> run_local_timers()
          -> hrtimer_run_queues()
            -> hrtimer_get_softirq_time() - tries to get a read lock

Now, Thomas assures me the fix is trivial, only do_timer() needs to be
done under the xtime_lock, and update_process_times() can savely be
removed from under it.

Signed-off-by: Peter Zijlstra 
Acked-by: Greg Ungerer 
CC: Richard Henderson 
CC: Bryan Wu 
CC: David Howells 
CC: Paul Mundt 
CC: William Irwin 
Acked-by: Ingo Molnar 
Acked-by: Ivan Kokshaysky 
Signed-off-by: Linus Torvalds

FRV: Fix up parse error in linker script

2008-02-13T16:26:01+00:00

Fix up parse error in FRV linker script, presumably introduced through changes
to the INIT_TEXT and EXIT_TEXT macros.

Signed-off-by: David Howells 
Signed-off-by: Linus Torvalds

ide: introduce HAVE_IDE

2008-02-09T09:46:40+00:00

To allow flexible configuration of IDE introduce HAVE_IDE.
All archs except arm, um and s390 unconditionally select it.
For arm the actual configuration determine if IDE is supported.

This is a step towards introducing drivers/Kconfig for arm.

Signed-off-by: Sam Ravnborg 
Acked-by: Russell King - ARM Linux 
Acked-by: Bartlomiej Zolnierkiewicz

CONFIG_HIGHPTE vs. sub-page page tables.

2008-02-08T17:22:42+00:00

Background: I've implemented 1K/2K page tables for s390.  These sub-page
page tables are required to properly support the s390 virtualization
instruction with KVM.  The SIE instruction requires that the page tables
have 256 page table entries (pte) followed by 256 page status table entries
(pgste).  The pgstes are only required if the process is using the SIE
instruction.  The pgstes are updated by the hardware and by the hypervisor
for a number of reasons, one of them is dirty and reference bit tracking.
To avoid wasting memory the standard pte table allocation should return
1K/2K (31/64 bit) and 2K/4K if the process is using SIE.

Problem: Page size on s390 is 4K, page table size is 1K or 2K.  That means
the s390 version for pte_alloc_one cannot return a pointer to a struct
page.  Trouble is that with the CONFIG_HIGHPTE feature on x86 pte_alloc_one
cannot return a pointer to a pte either, since that would require more than
32 bit for the return value of pte_alloc_one (and the pte * would not be
accessible since its not kmapped).

Solution: The only solution I found to this dilemma is a new typedef: a
pgtable_t.  For s390 pgtable_t will be a (pte *) - to be introduced with a
later patch.  For everybody else it will be a (struct page *).  The
additional problem with the initialization of the ptl lock and the
NR_PAGETABLE accounting is solved with a constructor pgtable_page_ctor and
a destructor pgtable_page_dtor.  The page table allocation and free
functions need to call these two whenever a page table page is allocated or
freed.  pmd_populate will get a pgtable_t instead of a struct page pointer.
 To get the pgtable_t back from a pmd entry that has been installed with
pmd_populate a new function pmd_pgtable is added.  It replaces the pmd_page
call in free_pte_range and apply_to_pte_range.

Signed-off-by: Martin Schwidefsky 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

avoid overflows in kernel/time.c

2008-02-08T17:22:39+00:00

When the conversion factor between jiffies and milli- or microseconds is
not a single multiply or divide, as for the case of HZ == 300, we currently
do a multiply followed by a divide.  The intervening result, however, is
subject to overflows, especially since the fraction is not simplified (for
HZ == 300, we multiply by 300 and divide by 1000).

This is exposed to the user when passing a large timeout to poll(), for
example.

This patch replaces the multiply-divide with a reciprocal multiplication on
32-bit platforms.  When the input is an unsigned long, there is no portable
way to do this on 64-bit platforms there is no portable way to do this
since it requires a 128-bit intermediate result (which gcc does support on
64-bit platforms but may generate libgcc calls, e.g.  on 64-bit s390), but
since the output is a 32-bit integer in the cases affected, just simplify
the multiply-divide (*3/10 instead of *300/1000).

The reciprocal multiply used can have off-by-one errors in the upper half
of the valid output range.  This could be avoided at the expense of having
to deal with a potential 65-bit intermediate result.  Since the intent is
to avoid overflow problems and most of the other time conversions are only
semiexact, the off-by-one errors were considered an acceptable tradeoff.

At Ralf Baechle's suggestion, this version uses a Perl script to compute
the necessary constants.  We already have dependencies on Perl for kernel
compiles.  This does, however, require the Perl module Math::BigInt, which
is included in the standard Perl distribution starting with version 5.8.0.
In order to support older versions of Perl, include a table of canned
constants in the script itself, and structure the script so that
Math::BigInt isn't required if pulling values from said table.

Running the script requires that the HZ value is available from the
Makefile.  Thus, this patch also adds the Kconfig variable CONFIG_HZ to the
architectures which didn't already have it (alpha, cris, frv, h8300, m32r,
m68k, m68knommu, sparc, v850, and xtensa.) It does *not* touch the sh or
sh64 architectures, since Paul Mundt has dealt with those separately in the
sh tree.

Signed-off-by: H. Peter Anvin 
Cc: Ralf Baechle ,
Cc: Sam Ravnborg ,
Cc: Paul Mundt ,
Cc: Richard Henderson ,
Cc: Michael Starvik ,
Cc: David Howells ,
Cc: Yoshinori Sato ,
Cc: Hirokazu Takata ,
Cc: Geert Uytterhoeven ,
Cc: Roman Zippel ,
Cc: William L. Irwin ,
Cc: Chris Zankel ,
Cc: H. Peter Anvin ,
Cc: Jan Engelhardt 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds