On Thu, Aug 29, 2019 at 01:07:04PM -0700, Tri Vo wrote:

On Thu, Aug 29, 2019 at 10:47 AM Nick Desaulniers
[off-list ref] wrote:

quoted

On Thu, Aug 29, 2019 at 8:48 AM Will Deacon [off-list ref] wrote:

quoted

From: Andrew Murray <redacted>

We no longer fall back to out-of-line atomics on systems with
CONFIG_ARM64_LSE_ATOMICS where ARM64_HAS_LSE_ATOMICS is not set.

Remove the unused compilation unit which provided these symbols.

Signed-off-by: Andrew Murray <redacted>
Signed-off-by: Will Deacon <will@kernel.org>
---
 arch/arm64/lib/Makefile       | 19 -------------------
 arch/arm64/lib/atomic_ll_sc.c |  3 ---
 2 files changed, 22 deletions(-)
 delete mode 100644 arch/arm64/lib/atomic_ll_sc.c

diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 33c2a4abda04..f10809ef1690 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile

@@ -11,25 +11,6 @@ CFLAGS_REMOVE_xor-neon.o     += -mgeneral-regs-only
 CFLAGS_xor-neon.o              += -ffreestanding
 endif

-# Tell the compiler to treat all general purpose registers (with the
-# exception of the IP registers, which are already handled by the caller
-# in case of a PLT) as callee-saved, which allows for efficient runtime
-# patching of the bl instruction in the caller with an atomic instruction
-# when supported by the CPU. Result and argument registers are handled
-# correctly, based on the function prototype.
-lib-$(CONFIG_ARM64_LSE_ATOMICS) += atomic_ll_sc.o
-CFLAGS_atomic_ll_sc.o  := -ffixed-x1 -ffixed-x2                        \
-                  -ffixed-x3 -ffixed-x4 -ffixed-x5 -ffixed-x6          \
-                  -ffixed-x7 -fcall-saved-x8 -fcall-saved-x9           \
-                  -fcall-saved-x10 -fcall-saved-x11 -fcall-saved-x12   \
-                  -fcall-saved-x13 -fcall-saved-x14 -fcall-saved-x15   \
-                  -fcall-saved-x18 -fomit-frame-pointer

+ Tri (who implemented support for -fcall-saved-x*, -ffixed-x* in
Clang).  I won't be sad to see the use of these flags go.

Nice! IMO these flags made the code hard to read.

Well, we didn't do it like that because it looked pretty ;)

Will

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