Messages in this thread | | | Date | Sat, 09 Feb 2019 18:28:25 +0100 | From | Stefan Agner <> | Subject | Re: [PATCH 4/5] ARM: use unified assembler in c files |
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Thanks for the reviews so far.
During some more testing I stumbled upon another issue:
On 07.02.2019 10:48, Stefan Agner wrote: > Use unified assembler syntax (UAL) in inline assembler. Divided > syntax is considered depricated. This will also allow to build > the kernel using LLVM's integrated assembler. > > Signed-off-by: Stefan Agner <stefan@agner.ch> > --- > arch/arm/mm/copypage-v4mc.c | 2 +- > arch/arm/mm/copypage-v4wb.c | 2 +- > arch/arm/mm/copypage-v4wt.c | 2 +- > 3 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/arm/mm/copypage-v4mc.c b/arch/arm/mm/copypage-v4mc.c > index b03202cddddb..b19c7ad1a6de 100644 > --- a/arch/arm/mm/copypage-v4mc.c > +++ b/arch/arm/mm/copypage-v4mc.c > @@ -56,7 +56,7 @@ 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) > diff --git a/arch/arm/mm/copypage-v4wb.c b/arch/arm/mm/copypage-v4wb.c > index cd3e165afeed..6e3c9b69dd25 100644 > --- a/arch/arm/mm/copypage-v4wb.c > +++ b/arch/arm/mm/copypage-v4wb.c > @@ -38,7 +38,7 @@ static void v4wb_copy_user_page(void *kto, const void *kfrom) > ldmia %1!, {r3, r4, ip, lr} @ 4\n\ > subs %2, %2, #1 @ 1\n\ > stmia %0!, {r3, r4, ip, lr} @ 4\n\ > - ldmneia %1!, {r3, r4, ip, lr} @ 4\n\ > + ldmiane %1!, {r3, r4, ip, lr} @ 4\n\ > bne 1b @ 1\n\ > mcr p15, 0, %1, c7, c10, 4 @ 1 drain WB" > : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp) > diff --git a/arch/arm/mm/copypage-v4wt.c b/arch/arm/mm/copypage-v4wt.c > index 8614572e1296..4a40fa1cbc2a 100644 > --- a/arch/arm/mm/copypage-v4wt.c > +++ b/arch/arm/mm/copypage-v4wt.c > @@ -34,7 +34,7 @@ static void v4wt_copy_user_page(void *kto, const void *kfrom) > ldmia %1!, {r3, r4, ip, lr} @ 4\n\ > subs %2, %2, #1 @ 1\n\ > stmia %0!, {r3, r4, ip, lr} @ 4\n\ > - ldmneia %1!, {r3, r4, ip, lr} @ 4\n\ > + ldmiane %1!, {r3, r4, ip, lr} @ 4\n\ > bne 1b @ 1\n\ > mcr p15, 0, %2, c7, c7, 0 @ flush ID cache" > : "+&r" (kto), "+&r" (kfrom), "=&r" (tmp)
When compiling with gcc, this leads to:
/tmp/ccrvA1wy.s: Assembler messages: /tmp/ccrvA1wy.s:180: Error: bad instruction `ldmiane r0!,{r3,r4,ip,lr}' make[1]: *** [scripts/Makefile.build:277: arch/arm/mm/copypage-v4wb.o] Error 1 make: *** [Makefile:1042: arch/arm/mm] Error 2
Unfortunately, the gcc option -masm-syntax-unified which allows unified syntax in inline assembly is broken (see also https://lkml.org/lkml/2019/1/7/1320).
So this requires to sprinkle those inline assembly with ".syntax unified" strings, similar to how I've done it in uaccess.h.
-- Stefan
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