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ARM: 8845/1: use unified assembler in c files

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Use unified assembler syntax (UAL) in inline assembler. Divided
syntax is considered deprecated. This will also allow to build
the kernel using LLVM's integrated assembler.

When compiling non-Thumb2 GCC always emits a ".syntax divided"
at the beginning of the inline assembly which makes the
assembler fail. Since GCC 5 there is the -masm-syntax-unified
GCC option which make GCC assume unified syntax asm and hence
emits ".syntax unified" even in ARM mode. However, the option
is broken since GCC version 6 (see GCC PR88648 [1]). Work
around by adding ".syntax unified" as part of the inline
assembly.

[0] https://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html#index-masm-syntax-unified
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88648

Signed-off-by: Stefan Agner <stefan@agner.ch>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
This commit is contained in:
Stefan Agner
2019-02-18 00:58:29 +01:00
committed by Russell King
parent e44fc38818
commit b7e8c9397c
3 changed files with 6 additions and 3 deletions
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3
arch/arm/mm/copypage-v4mc.c
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@@ -45,6 +45,7 @@ static void mc_copy_user_page(void *from, void *to)
int tmp;
asm volatile ("\
.syntax unified\n\
ldmia %0!, {r2, r3, ip, lr} @ 4\n\
1: mcr p15, 0, %1, c7, c6, 1 @ 1 invalidate D line\n\
stmia %1!, {r2, r3, ip, lr} @ 4\n\
@@ -56,7 +57,7 @@ static void mc_copy_user_page(void *from, void *to)
ldmia %0!, {r2, r3, ip, lr} @ 4\n\
subs %2, %2, #1 @ 1\n\
stmia %1!, {r2, r3, ip, lr} @ 4\n\
ldmneia %0!, {r2, r3, ip, lr} @ 4\n\
ldmiane %0!, {r2, r3, ip, lr} @ 4\n\
bne 1b @ "
: "+&r" (from), "+&r" (to), "=&r" (tmp)
: "2" (PAGE_SIZE / 64)