Commit Graph

4 Commits

Author SHA1 Message Date
Dave P Martin
6917c857e3 arm64: Avoid breakage caused by .altmacro in fpsimd save/restore macros
Alternate macro mode is not a property of a macro definition, but a
gas runtime state that alters the way macros are expanded for ever
after (until .noaltmacro is seen).

This means that subsequent assembly code that calls other macros can
break if fpsimdmacros.h is included.

Since these instruction sequences are simple (if dull -- but in a
good way), this patch solves the problem by simply expanding the
.irp loops.  The pre-existing fpsimd_{save,restore} macros weren't
rolled with .irp anyway and the sequences affected are short, so
this change restores consistency at little cost.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-01-29 17:24:39 +00:00
Will Deacon
5959e25729 arm64: fpsimd: avoid restoring fpcr if the contents haven't changed
Writing to the FPCR is commonly implemented as a self-synchronising
operation in the CPU, so avoid writing to the register when the saved
value matches that in the hardware already.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2014-07-18 10:21:17 +01:00
Ard Biesheuvel
190f1ca85d arm64: add support for kernel mode NEON in interrupt context
This patch modifies kernel_neon_begin() and kernel_neon_end(), so
they may be called from any context. To address the case where only
a couple of registers are needed, kernel_neon_begin_partial(u32) is
introduced which takes as a parameter the number of bottom 'n' NEON
q-registers required. To mark the end of such a partial section, the
regular kernel_neon_end() should be used.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
2014-05-08 11:31:57 +02:00
Marc Zyngier
cfc5180e5a arm64: move FP-SIMD save/restore code to a macro
In order to be able to reuse the save-restore code in KVM, move
it to a pair of macros, similar to what the 32bit code does.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-12-05 11:26:50 +00:00