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  1. 26 Feb, 2007 4 commits
  3. 23 Feb, 2007 21 commits
  5. 13 Feb, 2007 1 commit
  7. 02 Feb, 2007 6 commits
  9. 18 Jan, 2007 8 commits
    • Russell King's avatar
      [ARM] Provide basic printk_clock() implementation · d57fe6c0
      Russell King authored 
      Current sched_clock() implementations on ARM cause unbootable kernels
with PRINTK_TIME support enabled.  To avoid this, provide a basic
printk_clock() implementation which avoids sched_clock() being called
before the page tables have been set up.
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      d57fe6c0
    • Russell King's avatar
      [ARM] Fix VFP initialisation issue for SMP systems · 08de961a
      Russell King authored 
      When we install the handlers for context switching, we must enable
VFP on all CPU cores, otherwise undefined (and random) effects
occur.
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      08de961a
    • Richard Purdie's avatar
      [ARM] 4078/1: Fix ARM copypage cache coherency problems · 1b0c9083
      Richard Purdie authored 
      If PG_dcache_dirty is set for a page, we need to flush the source page
before performing any copypage operation using a different virtual address.

This fixes the copypage implementations for XScale, StrongARM and ARMv6.

This patch fixes segmentation faults seen in the dynamic linker under
the usage patterns in glibc 2.4/2.5.
Signed-off-by: default avatarRichard Purdie <rpurdie@rpsys.net>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      1b0c9083
    • Russell King's avatar
      [ARM] Fix warnings from asm/system.h · 19eecd50
      Russell King authored 
      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: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      19eecd50
    • Russell King's avatar
      [ARM] Fix BUG()s in ioremap() code · 7a998b09
      Russell King authored 
      We need to ensure that the area size is page aligned so that
remap_area_pte() doesn't increment the address past the end of
the desired area.
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      7a998b09
    • Russell King's avatar
      [ARM] Add more syscalls · 27d9101e
      Russell King authored 
      Add:
  sys_unshare
  sys_set_robust_list
  sys_get_robust_list
  sys_splice
  sys_arm_sync_file_range
  sys_tee
  sys_vmsplice
  sys_move_pages
  sys_getcpu

Special note about sys_arm_sync_file_range(), which is implemented as:

asmlinkage long sys_arm_sync_file_range(int fd, unsigned int flags,
                                        loff_t offset, loff_t nbytes)
{
        return sys_sync_file_range(fd, offset, nbytes, flags);
}

We can't export sys_sync_file_range() directly on ARM because the
argument list someone picked does not fit in the available registers.
Would be nice if... there was an arch maintainer review mechanism for
new syscalls before they hit the kernel.
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      27d9101e
    • Russell King's avatar
      [ARM] Provide a method to alter the control register · b0e407ac
      Russell King authored 
      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: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      b0e407ac
    • Nicolas Pitre's avatar
      [ARM] 4016/1: prefetch macro is wrong wrt gcc's "delete-null-pointer-checks" · 563c5768
      Nicolas Pitre authored 
       optimization

The gcc manual says:

|`-fdelete-null-pointer-checks'
|     Use global dataflow analysis to identify and eliminate useless
|     checks for null pointers.  The compiler assumes that dereferencing
|     a null pointer would have halted the program.  If a pointer is
|     checked after it has already been dereferenced, it cannot be null.
|     Enabled at levels `-O2', `-O3', `-Os'.

Now the problem can be seen with this test case:

#include <linux/prefetch.h>
extern void bar(char *x);
void foo(char *x)
{
	prefetch(x);
	if (x)
		bar(x);
}

Because the constraint to the inline asm used in the prefetch() macro is
a memory operand, gcc assumes that the asm code does dereference the
pointer and the delete-null-pointer-checks optimization kicks in.
Inspection of generated assembly for the above example shows that bar()
is indeed called unconditionally without any test on the value of x.

Of course in the prefetch case there is no real dereference and it
cannot be assumed that a null pointer would have been caught at that
point. This causes kernel oopses with constructs like
hlist_for_each_entry() where the list's 'next' content is prefetched
before the pointer is tested against NULL, and only when gcc feels like
applying this optimization which doesn't happen all the time with more
complex code.

It appears that the way to prevent delete-null-pointer-checks
optimization to occur in this case is to make prefetch() into a static
inline function instead of a macro. At least this is what is done on
x86_64 where a similar inline asm memory operand is used (I presume they
would have seen the same problem if it didn't work) and resulting code
for the above example confirms that.

An alternative would consist of replacing the memory operand by a
register operand containing the pointer, and use the addressing mode
explicitly in the asm template. But that would be less optimal than an
offsettable memory reference.
Signed-off-by: default avatarNicolas Pitre <nico@cam.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      563c5768