diff --git a/arch/arm64/kernel/smccc-call.S b/arch/arm64/kernel/smccc-call.S index 2def9d0dd3dd..487381164ff6 100644 --- a/arch/arm64/kernel/smccc-call.S +++ b/arch/arm64/kernel/smccc-call.S @@ -7,19 +7,48 @@ #include #include +#include + +/* + * If we have SMCCC v1.3 and (as is likely) no SVE state in + * the registers then set the SMCCC hint bit to say there's no + * need to preserve it. Do this by directly adjusting the SMCCC + * function value which is already stored in x0 ready to be called. + */ +SYM_FUNC_START(__arm_smccc_sve_check) + + ldr_l x16, smccc_has_sve_hint + cbz x16, 2f + + get_current_task x16 + ldr x16, [x16, #TSK_TI_FLAGS] + tbnz x16, #TIF_FOREIGN_FPSTATE, 1f // Any live FP state? + tbnz x16, #TIF_SVE, 2f // Does that state include SVE? + +1: orr x0, x0, ARM_SMCCC_1_3_SVE_HINT + +2: ret +SYM_FUNC_END(__arm_smccc_sve_check) +EXPORT_SYMBOL(__arm_smccc_sve_check) .macro SMCCC instr + stp x29, x30, [sp, #-16]! + mov x29, sp +alternative_if ARM64_SVE + bl __arm_smccc_sve_check +alternative_else_nop_endif \instr #0 - ldr x4, [sp] + ldr x4, [sp, #16] stp x0, x1, [x4, #ARM_SMCCC_RES_X0_OFFS] stp x2, x3, [x4, #ARM_SMCCC_RES_X2_OFFS] - ldr x4, [sp, #8] + ldr x4, [sp, #24] cbz x4, 1f /* no quirk structure */ ldr x9, [x4, #ARM_SMCCC_QUIRK_ID_OFFS] cmp x9, #ARM_SMCCC_QUIRK_QCOM_A6 b.ne 1f str x6, [x4, ARM_SMCCC_QUIRK_STATE_OFFS] -1: ret +1: ldp x29, x30, [sp], #16 + ret .endm /* diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c index 0f3437b4c97e..60ccf3e90d7d 100644 --- a/drivers/firmware/smccc/smccc.c +++ b/drivers/firmware/smccc/smccc.c @@ -16,6 +16,7 @@ static u32 smccc_version = ARM_SMCCC_VERSION_1_0; static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE; bool __ro_after_init smccc_trng_available = false; +u64 __ro_after_init smccc_has_sve_hint = false; void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit) { @@ -23,6 +24,9 @@ void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit) smccc_conduit = conduit; smccc_trng_available = smccc_probe_trng(); + if (IS_ENABLED(CONFIG_ARM64_SVE) && + smccc_version >= ARM_SMCCC_VERSION_1_3) + smccc_has_sve_hint = true; } enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void) diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index d4244467a21b..b23906d0652f 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -280,6 +280,8 @@ u32 arm_smccc_get_version(void); void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit); +extern u64 smccc_has_sve_hint; + /** * struct arm_smccc_res - Result from SMC/HVC call * @a0-a3 result values from registers 0 to 3 @@ -359,6 +361,15 @@ struct arm_smccc_quirk { } state; }; +/** + * __arm_smccc_sve_check() - Set the SVE hint bit when doing SMC calls + * + * Sets the SMCCC hint bit to indicate if there is live state in the SVE + * registers, this modifies x0 in place and should never be called from C + * code. + */ +asmlinkage unsigned long __arm_smccc_sve_check(unsigned long x0); + /** * __arm_smccc_smc() - make SMC calls * @a0-a7: arguments passed in registers 0 to 7 @@ -426,6 +437,20 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1, #endif +/* nVHE hypervisor doesn't have a current thread so needs separate checks */ +#if defined(CONFIG_ARM64_SVE) && !defined(__KVM_NVHE_HYPERVISOR__) + +#define SMCCC_SVE_CHECK ALTERNATIVE("nop \n", "bl __arm_smccc_sve_check \n", \ + ARM64_SVE) +#define smccc_sve_clobbers "x16", "x30", "cc", + +#else + +#define SMCCC_SVE_CHECK +#define smccc_sve_clobbers + +#endif + #define ___count_args(_0, _1, _2, _3, _4, _5, _6, _7, _8, x, ...) x #define __count_args(...) \ @@ -493,7 +518,7 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1, #define ___constraints(count) \ : __constraint_read_ ## count \ - : "memory" + : smccc_sve_clobbers "memory" #define __constraints(count) ___constraints(count) /* @@ -508,7 +533,8 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1, register unsigned long r2 asm("r2"); \ register unsigned long r3 asm("r3"); \ __declare_args(__count_args(__VA_ARGS__), __VA_ARGS__); \ - asm volatile(inst "\n" : \ + asm volatile(SMCCC_SVE_CHECK \ + inst "\n" : \ "=r" (r0), "=r" (r1), "=r" (r2), "=r" (r3) \ __constraints(__count_args(__VA_ARGS__))); \ if (___res) \