4.9-stable review patch. If anyone has any objections, please let me know.
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From: Stefan Agner stefan@agner.ch
(commit 4ea7bdc6b5b33427bbd3f41c333e21c1825462a3 upstream)
As documented in GCC naked functions should only use basic ASM syntax. The extended ASM or mixture of basic ASM and "C" code is not guaranteed. Currently this works because it was hard coded to follow and check GCC behavior for arguments and register placement.
Furthermore with clang using parameters in Extended asm in a naked function is not supported: arch/arm/firmware/trusted_foundations.c:47:10: error: parameter references not allowed in naked functions : "r" (type), "r" (arg1), "r" (arg2) ^
Use a regular function to be more portable. This aligns also with the other SMC call implementations e.g. in qcom_scm-32.c and bcm_kona_smc.c.
Cc: Dmitry Osipenko digetx@gmail.com Cc: Stephen Warren swarren@nvidia.com Cc: Thierry Reding treding@nvidia.com Signed-off-by: Stefan Agner stefan@agner.ch Signed-off-by: Thierry Reding treding@nvidia.com Signed-off-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm/firmware/trusted_foundations.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-)
--- a/arch/arm/firmware/trusted_foundations.c +++ b/arch/arm/firmware/trusted_foundations.c @@ -31,21 +31,25 @@
static unsigned long cpu_boot_addr;
-static void __naked tf_generic_smc(u32 type, u32 arg1, u32 arg2) +static void tf_generic_smc(u32 type, u32 arg1, u32 arg2) { + register u32 r0 asm("r0") = type; + register u32 r1 asm("r1") = arg1; + register u32 r2 asm("r2") = arg2; + asm volatile( ".arch_extension sec\n\t" - "stmfd sp!, {r4 - r11, lr}\n\t" + "stmfd sp!, {r4 - r11}\n\t" __asmeq("%0", "r0") __asmeq("%1", "r1") __asmeq("%2", "r2") "mov r3, #0\n\t" "mov r4, #0\n\t" "smc #0\n\t" - "ldmfd sp!, {r4 - r11, pc}" + "ldmfd sp!, {r4 - r11}\n\t" : - : "r" (type), "r" (arg1), "r" (arg2) - : "memory"); + : "r" (r0), "r" (r1), "r" (r2) + : "memory", "r3", "r12", "lr"); }
static int tf_set_cpu_boot_addr(int cpu, unsigned long boot_addr)