1 files changed, 113 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/security_features.h b/arch/powerpc/include/asm/security_features.h
new file mode 100644
index 000000000..27574f218
--- /dev/null
+++ b/arch/powerpc/include/asm/security_features.h
@@ -0,0 +1,113 @@
+/* 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);
+}
+
+#ifdef CONFIG_PPC_BOOK3S_64
+enum stf_barrier_type stf_barrier_type_get(void);
+#else
+static inline enum stf_barrier_type stf_barrier_type_get(void) { return STF_BARRIER_NONE; }
+#endif
+
+// 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 */