Commit Graph

6 Commits

Author SHA1 Message Date
Andre Przywara 005415a39a libc: memset: Fix MISRA issues
MISRA complained about "0"s not being followed by an "U" (please note
my protest about this!) and about values not being explicitly compared
to 0 (fair enough).
Also use explicit pointer types.

Fix those issues to make the CI happy.

Change-Id: I4d11e49c14f16223a71c78b0fc3e68ba9a1382d3
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
2021-02-24 09:33:59 +00:00
Andre Przywara 75fab6496e libc: memset: improve performance by avoiding single byte writes
Currently our memset() implementation is safe, but slow. The main reason
for that seems to be the single byte writes that it issues, which can
show horrible performance, depending on the implementation of the
load/store subsystem.

Improve the algorithm by trying to issue 64-bit writes. As this only
works with aligned pointers, have a head and a tail section which
covers unaligned pointers, and leave the bulk of the work to the middle
section that does use 64-bit writes.

Put through some unit tests, which exercise all combinations of nasty
input parameters (pointers with various alignments, various odd and even
sizes, corner cases of content to write (-1, 256)).

Change-Id: I28ddd3d388cc4989030f1a70447581985368d5bb
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
2020-09-03 23:00:24 +01:00
Mark Dykes f5402ef7a8 Revert "libc/memset: Implement function in assembler"
This reverts commit e7d344de01.
 This reverts the patch https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/5313 due to a timing issue with the merge.  The merge occurred at the same time as the additional comments and thusly were were not seen until the merge was done.  This reverts the change and additional patches from Alexei will follow to address the concerns expressed in the orignal patch.

Change-Id: Iae5f6403c93ac13ceeda29463883fcd4c437f2b7
2020-08-21 19:33:46 +00:00
Alexei Fedorov e7d344de01 libc/memset: Implement function in assembler
Trace analysis of FVP_Base_AEMv8A model running in
Aarch32 mode with the build options listed below:
TRUSTED_BOARD_BOOT=1 GENERATE_COT=1
ARM_ROTPK_LOCATION=devel_ecdsa KEY_ALG=ecdsa
ROT_KEY=plat/arm/board/common/rotpk/arm_rotprivk_ecdsa.pem
shows that when auth_signature() gets called
71.84% of CPU execution time is spent in memset() function
written in C using single byte write operations,
see lib\libc\memset.c.
This patch replaces C memset() implementation with assembler
version giving the following results:
- for Aarch32 in auth_signature() call memset() CPU time
reduced to 24.84%.
- Number of CPU instructions executed during TF-A
boot stage before start of BL33 in RELEASE builds:
----------------------------------------------
|  Arch   |     C      |  assembler |    %   |
----------------------------------------------
| Aarch32 | 2073275460 | 1487400003 | -28.25 |
| Aarch64 | 2056807158 | 1244898303 | -39.47 |
----------------------------------------------
The patch also replaces memset.c with aarch64/memset.S
in plat\nvidia\tegra\platform.mk.

Change-Id: Ifbf085a2f577a25491e2d28446ee95a4ac891597
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>
2020-08-19 18:21:39 +00:00
Ambroise Vincent 609e053caa Remove several warnings reported with W=1
Improved support for W=1 compilation flag by solving missing-prototypes
and old-style-definition warnings.

The libraries are compiling with warnings (which turn into errors with
the Werror flag).

Outside of libraries, some warnings cannot be fixed without heavy
structural changes.

Change-Id: I1668cf99123ac4195c2a6a1d48945f7a64c67f16
Signed-off-by: Ambroise Vincent <ambroise.vincent@arm.com>
2019-04-01 10:43:42 +01:00
Antonio Nino Diaz 4661abc7c4 libc: Cleanup remaining files
The existing files had some style problems that this patch fixes.

Change-Id: I794e0d96e52f8da0ffa0d70a41f36c4432b4e563
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
2018-08-22 10:26:04 +01:00