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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Security related feature bit definitions.
*
* Copyright 2018, Michael Ellerman, IBM Corporation.
*/
#ifndef _ASM_POWERPC_SECURITY_FEATURES_H
#define _ASM_POWERPC_SECURITY_FEATURES_H
extern u64 powerpc_security_features;
extern bool rfi_flush;
/* These are bit flags */
enum stf_barrier_type {
STF_BARRIER_NONE = 0x1,
STF_BARRIER_FALLBACK = 0x2,
STF_BARRIER_EIEIO = 0x4,
STF_BARRIER_SYNC_ORI = 0x8,
};
void setup_stf_barrier(void);
void do_stf_barrier_fixups(enum stf_barrier_type types);
void setup_count_cache_flush(void);
static inline void security_ftr_set(u64 feature)
{
powerpc_security_features |= feature;
}
static inline void security_ftr_clear(u64 feature)
{
powerpc_security_features &= ~feature;
}
static inline bool security_ftr_enabled(u64 feature)
{
return !!(powerpc_security_features & feature);
}
// Features indicating support for Spectre/Meltdown mitigations
// The L1-D cache can be flushed with ori r30,r30,0
#define SEC_FTR_L1D_FLUSH_ORI30 0x0000000000000001ull
// The L1-D cache can be flushed with mtspr 882,r0 (aka SPRN_TRIG2)
#define SEC_FTR_L1D_FLUSH_TRIG2 0x0000000000000002ull
// ori r31,r31,0 acts as a speculation barrier
#define SEC_FTR_SPEC_BAR_ORI31 0x0000000000000004ull
// Speculation past bctr is disabled
#define SEC_FTR_BCCTRL_SERIALISED 0x0000000000000008ull
// Entries in L1-D are private to a SMT thread
#define SEC_FTR_L1D_THREAD_PRIV 0x0000000000000010ull
// Indirect branch prediction cache disabled
#define SEC_FTR_COUNT_CACHE_DISABLED 0x0000000000000020ull
// bcctr 2,0,0 triggers a hardware assisted count cache flush
#define SEC_FTR_BCCTR_FLUSH_ASSIST 0x0000000000000800ull
// bcctr 2,0,0 triggers a hardware assisted link stack flush
#define SEC_FTR_BCCTR_LINK_FLUSH_ASSIST 0x0000000000002000ull
// Features indicating need for Spectre/Meltdown mitigations
// The L1-D cache should be flushed on MSR[HV] 1->0 transition (hypervisor to guest)
#define SEC_FTR_L1D_FLUSH_HV 0x0000000000000040ull
// The L1-D cache should be flushed on MSR[PR] 0->1 transition (kernel to userspace)
#define SEC_FTR_L1D_FLUSH_PR 0x0000000000000080ull
// A speculation barrier should be used for bounds checks (Spectre variant 1)
#define SEC_FTR_BNDS_CHK_SPEC_BAR 0x0000000000000100ull
// Firmware configuration indicates user favours security over performance
#define SEC_FTR_FAVOUR_SECURITY 0x0000000000000200ull
// Software required to flush count cache on context switch
#define SEC_FTR_FLUSH_COUNT_CACHE 0x0000000000000400ull
// Software required to flush link stack on context switch
#define SEC_FTR_FLUSH_LINK_STACK 0x0000000000001000ull
// The L1-D cache should be flushed when entering the kernel
#define SEC_FTR_L1D_FLUSH_ENTRY 0x0000000000004000ull
// The L1-D cache should be flushed after user accesses from the kernel
#define SEC_FTR_L1D_FLUSH_UACCESS 0x0000000000008000ull
// The STF flush should be executed on privilege state switch
#define SEC_FTR_STF_BARRIER 0x0000000000010000ull
// Features enabled by default
#define SEC_FTR_DEFAULT \
(SEC_FTR_L1D_FLUSH_HV | \
SEC_FTR_L1D_FLUSH_PR | \
SEC_FTR_BNDS_CHK_SPEC_BAR | \
SEC_FTR_L1D_FLUSH_ENTRY | \
SEC_FTR_L1D_FLUSH_UACCESS | \
SEC_FTR_STF_BARRIER | \
SEC_FTR_FAVOUR_SECURITY)
#endif /* _ASM_POWERPC_SECURITY_FEATURES_H */
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