![Will Deacon](/assets/img/avatar_default.png)
In cases where x30 is used as a temporary in the out-of-line ll/sc atomics (e.g. atomic_fetch_add), the compiler tends to put out a full stackframe, which included pointing the x29 at the new frame. Since these things aren't traceable anyway, we can pass -fomit-frame-pointer to reduce the work when spilling. Since this is incompatible with -pg, we also remove that from the CFLAGS for this file. Signed-off-by: Will Deacon <will.deacon@arm.com>
24 lines
1.1 KiB
Makefile
24 lines
1.1 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
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lib-y := bitops.o clear_user.o delay.o copy_from_user.o \
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copy_to_user.o copy_in_user.o copy_page.o \
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clear_page.o memchr.o memcpy.o memmove.o memset.o \
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memcmp.o strcmp.o strncmp.o strlen.o strnlen.o \
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strchr.o strrchr.o tishift.o
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# Tell the compiler to treat all general purpose registers (with the
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# exception of the IP registers, which are already handled by the caller
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# in case of a PLT) as callee-saved, which allows for efficient runtime
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# patching of the bl instruction in the caller with an atomic instruction
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# when supported by the CPU. Result and argument registers are handled
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# correctly, based on the function prototype.
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lib-$(CONFIG_ARM64_LSE_ATOMICS) += atomic_ll_sc.o
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CFLAGS_atomic_ll_sc.o := -fcall-used-x0 -ffixed-x1 -ffixed-x2 \
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-ffixed-x3 -ffixed-x4 -ffixed-x5 -ffixed-x6 \
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-ffixed-x7 -fcall-saved-x8 -fcall-saved-x9 \
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-fcall-saved-x10 -fcall-saved-x11 -fcall-saved-x12 \
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-fcall-saved-x13 -fcall-saved-x14 -fcall-saved-x15 \
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-fcall-saved-x18 -fomit-frame-pointer
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CFLAGS_REMOVE_atomic_ll_sc.o := -pg
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lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o
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