1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * Security related feature bit definitions. 4 * 5 * Copyright 2018, Michael Ellerman, IBM Corporation. 6 */ 7 8 #ifndef _ASM_POWERPC_SECURITY_FEATURES_H 9 #define _ASM_POWERPC_SECURITY_FEATURES_H 10 11 12 extern unsigned long powerpc_security_features; 13 extern bool rfi_flush; 14 15 static inline void security_ftr_set(unsigned long feature) 16 { 17 powerpc_security_features |= feature; 18 } 19 20 static inline void security_ftr_clear(unsigned long feature) 21 { 22 powerpc_security_features &= ~feature; 23 } 24 25 static inline bool security_ftr_enabled(unsigned long feature) 26 { 27 return !!(powerpc_security_features & feature); 28 } 29 30 31 // Features indicating support for Spectre/Meltdown mitigations 32 33 // The L1-D cache can be flushed with ori r30,r30,0 34 #define SEC_FTR_L1D_FLUSH_ORI30 0x0000000000000001ull 35 36 // The L1-D cache can be flushed with mtspr 882,r0 (aka SPRN_TRIG2) 37 #define SEC_FTR_L1D_FLUSH_TRIG2 0x0000000000000002ull 38 39 // ori r31,r31,0 acts as a speculation barrier 40 #define SEC_FTR_SPEC_BAR_ORI31 0x0000000000000004ull 41 42 // Speculation past bctr is disabled 43 #define SEC_FTR_BCCTRL_SERIALISED 0x0000000000000008ull 44 45 // Entries in L1-D are private to a SMT thread 46 #define SEC_FTR_L1D_THREAD_PRIV 0x0000000000000010ull 47 48 // Indirect branch prediction cache disabled 49 #define SEC_FTR_COUNT_CACHE_DISABLED 0x0000000000000020ull 50 51 52 // Features indicating need for Spectre/Meltdown mitigations 53 54 // The L1-D cache should be flushed on MSR[HV] 1->0 transition (hypervisor to guest) 55 #define SEC_FTR_L1D_FLUSH_HV 0x0000000000000040ull 56 57 // The L1-D cache should be flushed on MSR[PR] 0->1 transition (kernel to userspace) 58 #define SEC_FTR_L1D_FLUSH_PR 0x0000000000000080ull 59 60 // A speculation barrier should be used for bounds checks (Spectre variant 1) 61 #define SEC_FTR_BNDS_CHK_SPEC_BAR 0x0000000000000100ull 62 63 // Firmware configuration indicates user favours security over performance 64 #define SEC_FTR_FAVOUR_SECURITY 0x0000000000000200ull 65 66 67 // Features enabled by default 68 #define SEC_FTR_DEFAULT \ 69 (SEC_FTR_L1D_FLUSH_HV | \ 70 SEC_FTR_L1D_FLUSH_PR | \ 71 SEC_FTR_BNDS_CHK_SPEC_BAR | \ 72 SEC_FTR_FAVOUR_SECURITY) 73 74 #endif /* _ASM_POWERPC_SECURITY_FEATURES_H */ 75