Commit Graph

12 Commits

Author SHA1 Message Date
Nicolas Pitre
2d2669b629 [PATCH] ARM: 2651/3: kernel helpers for NPTL support
Patch from Nicolas Pitre

This patch entirely reworks the kernel assistance for NPTL on ARM.
In particular this provides an efficient way to retrieve the TLS
value and perform atomic operations without any instruction emulation
nor special system call.  This even allows for pre ARMv6 binaries to
be forward compatible with SMP systems without any penalty.
The problematic and performance critical operations are performed
through segment of kernel provided user code reachable from user space
at a fixed address in kernel memory.  Those fixed entry points are
within the vector page so we basically get it for free as no extra
memory page is required and nothing else may be mapped at that
location anyway.
This is different from (but doesn't preclude) a full blown VDSO
implementation, however a VDSO would prevent some assembly tricks with
constants that allows for efficient branching to those code segments.
And since those code segments only use a few cycles before returning to
user code, the overhead of a VDSO far call would add a significant
overhead to such minimalistic operations.
The ARM_NR_set_tls syscall also changed number.  This is done for two
reasons:
1) this patch changes the way the TLS value was previously meant to be
   retrieved, therefore we ensure whatever library using the old way
   gets fixed (they only exist in private tree at the moment since the
   NPTL work is still progressing).
2) the previous number was allocated in a range causing an undefined
   instruction trap on kernels not supporting that syscall and it was
   determined that allocating it in a range returning -ENOSYS would be
   much nicer for libraries trying to determine if the feature is
   present or not.

Signed-off-by: Nicolas Pitre
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-04-29 22:08:33 +01:00
Russell King
bce495d865 [PATCH] ARM: make entry*.S includes more logical
Move common includes to entry-header, and file specific includes
to the relevant file.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-26 15:21:02 +01:00
Russell King
f4dc9a4cf2 [PATCH] ARM: Remove single-use user save/restore macros
Assembly macros are pointless if they're only used once.  Move
them inline.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-26 15:20:34 +01:00
Russell King
cf88b417f9 [PATCH] ARM: remove PT_TRACESYS
PT_TRACESYS is unused, remove it.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-26 15:20:12 +01:00
Russell King
acaca3c915 [PATCH] ARM: Remove SVC_MODE definition
SVC_MODE reflects the MODE_SVC definition in asm/ptrace.h.  Use
the asm/ptrace.h definition instead, and remove SVC_MODE.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-26 15:19:48 +01:00
Russell King
e0f9f4a622 [PATCH] ARM: Use __NR_SYSCALL_BASE and __ARM_NR_BASE in asm code
Don't define our own local constants, but use those already defined
in asm/unistd.h instead.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-26 15:19:24 +01:00
Russell King
925c8a1a8c [PATCH] ARM: pt_regs offsets
Generate pt_regs S_xx offsets from the structure itself instead
of #defining them.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-26 15:18:59 +01:00
Russell King
1ec42c0c97 [PATCH] ARM: Remove argument for disable_irq/enable_irq
Since we do not require a register for these operations, we can
remove this unnecessary argument.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-26 15:18:26 +01:00
Russell King
7933523dc7 [PATCH] ARM: remove some entry initialisation asm code
Convert the trivial vector entry initialisation code to C code.

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-26 15:17:42 +01:00
Hugh Dickins
6119be0bba [PATCH] freepgt: arm FIRST_USER_ADDRESS PAGE_SIZE
ARM define FIRST_USER_ADDRESS as PAGE_SIZE (beyond the machine vectors when
they are mapped low), and use that definition in place of locally defined
MIN_MAP_ADDR.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-19 13:29:21 -07:00
Russell King
652a12ef98 [PATCH] ARM: showregs
Fix show_regs() to provide a backtrace.  Provide a new __show_regs()
function which implements the common subset of show_regs() and die().
Add prototypes to asm-arm/system.h

Signed-off-by: Russell King <rmk@arm.linux.org.uk>
2005-04-17 15:50:36 +01:00
Linus Torvalds
1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00