[Buildroot] [PATCH] uclibc: arc: Disable usage of atomic ops if hardware has no LLSC

Alexey Brodkin Alexey.Brodkin at synopsys.com
Wed Apr 19 17:48:57 UTC 2017


Since uClibc-ng v1.0.20 we may force libc to either use llock/scond
instructions for atomic ops or if those are missing use kernel-assisted
emulation. By defult atomics are used so we disable that feature in libc
if we build for target without LLSC.

This allows us to build and use NPTL on ARC750 for example which was
not possible before.

Signed-off-by: Alexey Brodkin <abrodkin at synopsys.com>
Cc: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
Cc: Peter Korsgaard <peter at korsgaard.com>
---
 package/uclibc/uclibc.mk | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/package/uclibc/uclibc.mk b/package/uclibc/uclibc.mk
index 45bb6dede..ce7f23f25 100644
--- a/package/uclibc/uclibc.mk
+++ b/package/uclibc/uclibc.mk
@@ -101,6 +101,12 @@ define UCLIBC_ARC_PAGE_SIZE_CONFIG
 	$(call KCONFIG_ENABLE_OPT,$(UCLIBC_ARC_PAGE_SIZE),$(@D)/.config)
 endef
 
+ifneq ($(BR2_ARC_ATOMIC_EXT),y)
+define UCLIBC_ARC_ATOMICS_CONFIG
+	$(call KCONFIG_DISABLE_OPT,CONFIG_ARC_HAS_ATOMICS,$(@D)/.config)
+endef
+endif
+
 endif # arc
 
 #
@@ -395,6 +401,7 @@ define UCLIBC_KCONFIG_FIXUP_CMDS
 	$(UCLIBC_BINFMT_CONFIG)
 	$(UCLIBC_ARC_TYPE_CONFIG)
 	$(UCLIBC_ARC_PAGE_SIZE_CONFIG)
+	$(UCLIBC_ARC_ATOMICS_CONFIG)
 	$(UCLIBC_ARM_ABI_CONFIG)
 	$(UCLIBC_ARM_BINFMT_FLAT)
 	$(UCLIBC_ARM_NO_CONTEXT_FUNCS)
-- 
2.11.0



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