Merge tag 'arc-4.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc
Vineet writes:
"ARC updates for 4.19-rc8
- Fix clone syscall to update Thread pointer register
- Make/build updates (needed for AGL/OE builds) [Alexey]
- Typo fix [Colin Ian King]"
* tag 'arc-4.19-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
ARC: clone syscall to setp r25 as thread pointer
ARC: build: Don't set CROSS_COMPILE in arch's Makefile
ARC: fix spelling mistake "entires" -> "entries"
ARC: build: Get rid of toolchain check
ARCv2: build: use mcpu=hs38 iso generic mcpu=archs
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index b4441b0..a045f30 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -149,7 +149,7 @@
Support for ARC770 core introduced with Rel 4.10 (Summer 2011)
This core has a bunch of cool new features:
-MMU-v3: Variable Page Sz (4k, 8k, 16k), bigger J-TLB (128x4)
- Shared Address Spaces (for sharing TLB entires in MMU)
+ Shared Address Spaces (for sharing TLB entries in MMU)
-Caches: New Prog Model, Region Flush
-Insns: endian swap, load-locked/store-conditional, time-stamp-ctr
diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index 99cce77..644815c 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -6,33 +6,11 @@
# published by the Free Software Foundation.
#
-ifeq ($(CROSS_COMPILE),)
-ifndef CONFIG_CPU_BIG_ENDIAN
-CROSS_COMPILE := arc-linux-
-else
-CROSS_COMPILE := arceb-linux-
-endif
-endif
-
KBUILD_DEFCONFIG := nsim_700_defconfig
cflags-y += -fno-common -pipe -fno-builtin -mmedium-calls -D__linux__
cflags-$(CONFIG_ISA_ARCOMPACT) += -mA7
-cflags-$(CONFIG_ISA_ARCV2) += -mcpu=archs
-
-is_700 = $(shell $(CC) -dM -E - < /dev/null | grep -q "ARC700" && echo 1 || echo 0)
-
-ifdef CONFIG_ISA_ARCOMPACT
-ifeq ($(is_700), 0)
- $(error Toolchain not configured for ARCompact builds)
-endif
-endif
-
-ifdef CONFIG_ISA_ARCV2
-ifeq ($(is_700), 1)
- $(error Toolchain not configured for ARCv2 builds)
-endif
-endif
+cflags-$(CONFIG_ISA_ARCV2) += -mcpu=hs38
ifdef CONFIG_ARC_CURR_IN_REG
# For a global register defintion, make sure it gets passed to every file
@@ -79,7 +57,7 @@
cflags-$(CONFIG_CPU_BIG_ENDIAN) += -mbig-endian
ldflags-$(CONFIG_CPU_BIG_ENDIAN) += -EB
-LIBGCC := $(shell $(CC) $(cflags-y) --print-libgcc-file-name)
+LIBGCC = $(shell $(CC) $(cflags-y) --print-libgcc-file-name)
# Modules with short calls might break for calls into builtin-kernel
KBUILD_CFLAGS_MODULE += -mlong-calls -mno-millicode
diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c
index 4674541..8ce6e72 100644
--- a/arch/arc/kernel/process.c
+++ b/arch/arc/kernel/process.c
@@ -241,6 +241,26 @@
task_thread_info(current)->thr_ptr;
}
+
+ /*
+ * setup usermode thread pointer #1:
+ * when child is picked by scheduler, __switch_to() uses @c_callee to
+ * populate usermode callee regs: this works (despite being in a kernel
+ * function) since special return path for child @ret_from_fork()
+ * ensures those regs are not clobbered all the way to RTIE to usermode
+ */
+ c_callee->r25 = task_thread_info(p)->thr_ptr;
+
+#ifdef CONFIG_ARC_CURR_IN_REG
+ /*
+ * setup usermode thread pointer #2:
+ * however for this special use of r25 in kernel, __switch_to() sets
+ * r25 for kernel needs and only in the final return path is usermode
+ * r25 setup, from pt_regs->user_r25. So set that up as well
+ */
+ c_regs->user_r25 = c_callee->r25;
+#endif
+
return 0;
}
