From: Mark Rutland mark.rutland@arm.com
From: Marc Zyngier marc.zyngier@arm.com
commit f2d3b2e8759a5833df6f022e42df2d581e6d843c upstream.
One of the major improvement of SMCCC v1.1 is that it only clobbers the first 4 registers, both on 32 and 64bit. This means that it becomes very easy to provide an inline version of the SMC call primitive, and avoid performing a function call to stash the registers that would otherwise be clobbered by SMCCC v1.0.
Reviewed-by: Robin Murphy robin.murphy@arm.com Tested-by: Ard Biesheuvel ard.biesheuvel@linaro.org Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Mark Rutland mark.rutland@arm.com [v4.9 backport] Tested-by: Greg Hackmann ghackmann@google.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Ard Biesheuvel ardb@kernel.org --- include/linux/arm-smccc.h | 141 ++++++++++++++++++++ 1 file changed, 141 insertions(+)
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index 82e1f3ae4010..eb79d0e21148 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -123,5 +123,146 @@ asmlinkage void arm_smccc_hvc(unsigned long a0, unsigned long a1, unsigned long a5, unsigned long a6, unsigned long a7, struct arm_smccc_res *res);
+/* SMCCC v1.1 implementation madness follows */ +#ifdef CONFIG_ARM64 + +#define SMCCC_SMC_INST "smc #0" +#define SMCCC_HVC_INST "hvc #0" + +#elif defined(CONFIG_ARM) +#include <asm/opcodes-sec.h> +#include <asm/opcodes-virt.h> + +#define SMCCC_SMC_INST __SMC(0) +#define SMCCC_HVC_INST __HVC(0) + +#endif + +#define ___count_args(_0, _1, _2, _3, _4, _5, _6, _7, _8, x, ...) x + +#define __count_args(...) \ + ___count_args(__VA_ARGS__, 7, 6, 5, 4, 3, 2, 1, 0) + +#define __constraint_write_0 \ + "+r" (r0), "=&r" (r1), "=&r" (r2), "=&r" (r3) +#define __constraint_write_1 \ + "+r" (r0), "+r" (r1), "=&r" (r2), "=&r" (r3) +#define __constraint_write_2 \ + "+r" (r0), "+r" (r1), "+r" (r2), "=&r" (r3) +#define __constraint_write_3 \ + "+r" (r0), "+r" (r1), "+r" (r2), "+r" (r3) +#define __constraint_write_4 __constraint_write_3 +#define __constraint_write_5 __constraint_write_4 +#define __constraint_write_6 __constraint_write_5 +#define __constraint_write_7 __constraint_write_6 + +#define __constraint_read_0 +#define __constraint_read_1 +#define __constraint_read_2 +#define __constraint_read_3 +#define __constraint_read_4 "r" (r4) +#define __constraint_read_5 __constraint_read_4, "r" (r5) +#define __constraint_read_6 __constraint_read_5, "r" (r6) +#define __constraint_read_7 __constraint_read_6, "r" (r7) + +#define __declare_arg_0(a0, res) \ + struct arm_smccc_res *___res = res; \ + register u32 r0 asm("r0") = a0; \ + register unsigned long r1 asm("r1"); \ + register unsigned long r2 asm("r2"); \ + register unsigned long r3 asm("r3") + +#define __declare_arg_1(a0, a1, res) \ + struct arm_smccc_res *___res = res; \ + register u32 r0 asm("r0") = a0; \ + register typeof(a1) r1 asm("r1") = a1; \ + register unsigned long r2 asm("r2"); \ + register unsigned long r3 asm("r3") + +#define __declare_arg_2(a0, a1, a2, res) \ + struct arm_smccc_res *___res = res; \ + register u32 r0 asm("r0") = a0; \ + register typeof(a1) r1 asm("r1") = a1; \ + register typeof(a2) r2 asm("r2") = a2; \ + register unsigned long r3 asm("r3") + +#define __declare_arg_3(a0, a1, a2, a3, res) \ + struct arm_smccc_res *___res = res; \ + register u32 r0 asm("r0") = a0; \ + register typeof(a1) r1 asm("r1") = a1; \ + register typeof(a2) r2 asm("r2") = a2; \ + register typeof(a3) r3 asm("r3") = a3 + +#define __declare_arg_4(a0, a1, a2, a3, a4, res) \ + __declare_arg_3(a0, a1, a2, a3, res); \ + register typeof(a4) r4 asm("r4") = a4 + +#define __declare_arg_5(a0, a1, a2, a3, a4, a5, res) \ + __declare_arg_4(a0, a1, a2, a3, a4, res); \ + register typeof(a5) r5 asm("r5") = a5 + +#define __declare_arg_6(a0, a1, a2, a3, a4, a5, a6, res) \ + __declare_arg_5(a0, a1, a2, a3, a4, a5, res); \ + register typeof(a6) r6 asm("r6") = a6 + +#define __declare_arg_7(a0, a1, a2, a3, a4, a5, a6, a7, res) \ + __declare_arg_6(a0, a1, a2, a3, a4, a5, a6, res); \ + register typeof(a7) r7 asm("r7") = a7 + +#define ___declare_args(count, ...) __declare_arg_ ## count(__VA_ARGS__) +#define __declare_args(count, ...) ___declare_args(count, __VA_ARGS__) + +#define ___constraints(count) \ + : __constraint_write_ ## count \ + : __constraint_read_ ## count \ + : "memory" +#define __constraints(count) ___constraints(count) + +/* + * We have an output list that is not necessarily used, and GCC feels + * entitled to optimise the whole sequence away. "volatile" is what + * makes it stick. + */ +#define __arm_smccc_1_1(inst, ...) \ + do { \ + __declare_args(__count_args(__VA_ARGS__), __VA_ARGS__); \ + asm volatile(inst "\n" \ + __constraints(__count_args(__VA_ARGS__))); \ + if (___res) \ + *___res = (typeof(*___res)){r0, r1, r2, r3}; \ + } while (0) + +/* + * arm_smccc_1_1_smc() - make an SMCCC v1.1 compliant SMC call + * + * This is a variadic macro taking one to eight source arguments, and + * an optional return structure. + * + * @a0-a7: arguments passed in registers 0 to 7 + * @res: result values from registers 0 to 3 + * + * This macro is used to make SMC calls following SMC Calling Convention v1.1. + * The content of the supplied param are copied to registers 0 to 7 prior + * to the SMC instruction. The return values are updated with the content + * from register 0 to 3 on return from the SMC instruction if not NULL. + */ +#define arm_smccc_1_1_smc(...) __arm_smccc_1_1(SMCCC_SMC_INST, __VA_ARGS__) + +/* + * arm_smccc_1_1_hvc() - make an SMCCC v1.1 compliant HVC call + * + * This is a variadic macro taking one to eight source arguments, and + * an optional return structure. + * + * @a0-a7: arguments passed in registers 0 to 7 + * @res: result values from registers 0 to 3 + * + * This macro is used to make HVC calls following SMC Calling Convention v1.1. + * The content of the supplied param are copied to registers 0 to 7 prior + * to the HVC instruction. The return values are updated with the content + * from register 0 to 3 on return from the HVC instruction if not NULL. + */ +#define arm_smccc_1_1_hvc(...) __arm_smccc_1_1(SMCCC_HVC_INST, __VA_ARGS__) + #endif /*__ASSEMBLY__*/ #endif /*__LINUX_ARM_SMCCC_H*/