[PATCH v9 10/36] x86/fred: Add a new header file for FRED definitions

[Xin Li <xin3.li@xxxxxxxxx>]

From: "H. Peter Anvin (Intel)" <hpa@xxxxxxxxx>

Add a header file for FRED prototypes and definitions.

Signed-off-by: H. Peter Anvin (Intel) <hpa@xxxxxxxxx>
Tested-by: Shan Kang <shan.kang@xxxxxxxxx>
Signed-off-by: Xin Li <xin3.li@xxxxxxxxx>
---

Changes since v6:
* Replace pt_regs csx flags prefix FRED_CSL_ with FRED_CSX_.
---
 arch/x86/include/asm/fred.h | 104 ++++++++++++++++++++++++++++++++++++
 1 file changed, 104 insertions(+)
 create mode 100644 arch/x86/include/asm/fred.h

diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h
new file mode 100644
index 000000000000..d76e681a806f
--- /dev/null
+++ b/arch/x86/include/asm/fred.h
@@ -0,0 +1,104 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Macros for Flexible Return and Event Delivery (FRED)
+ */
+
+#ifndef ASM_X86_FRED_H
+#define ASM_X86_FRED_H
+
+#include <linux/const.h>
+#include <asm/asm.h>
+
+/*
+ * FRED return instructions
+ *
+ * Replace with "ERETS"/"ERETU" once binutils support FRED return instructions.
+ * The binutils version supporting FRED instructions is still TBD, and will
+ * update once we have it.
+ */
+#define ERETS                  _ASM_BYTES(0xf2,0x0f,0x01,0xca)
+#define ERETU                  _ASM_BYTES(0xf3,0x0f,0x01,0xca)
+
+/*
+ * RSP is aligned to a 64-byte boundary before used to push a new stack frame
+ */
+#define FRED_STACK_FRAME_RSP_MASK      _AT(unsigned long, (~0x3f))
+
+/*
+ * Event stack level macro for the FRED_STKLVLS MSR.
+ * Usage example: FRED_STKLVL(X86_TRAP_DF, 3)
+ * Multiple values can be ORd together.
+ */
+#define FRED_STKLVL(v,l)       (_AT(unsigned long, l) << (2*(v)))
+
+/* FRED_CONFIG MSR */
+#define FRED_CONFIG_CSL_MASK           0x3
+/*
+ * Used for the return address for call emulation during code patching,
+ * and measured in 64-byte cache lines.
+ */
+#define FRED_CONFIG_REDZONE_AMOUNT     1
+#define FRED_CONFIG_REDZONE            (_AT(unsigned long, 
FRED_CONFIG_REDZONE_AMOUNT) << 6)
+#define FRED_CONFIG_INT_STKLVL(l)      (_AT(unsigned long, l) << 9)
+#define FRED_CONFIG_ENTRYPOINT(p)      _AT(unsigned long, (p))
+
+/*
+ * FRED event type and vector bit width and counts.
+ *
+ * There is space in the stack frame making it possible to extend event type
+ * and vector fields in the future.
+ */
+#define FRED_EVENT_TYPE_BITS           3
+#define FRED_EVENT_TYPE_COUNT          _BITUL(FRED_EVENT_TYPE_BITS)
+#define FRED_EVENT_VECTOR_BITS         8
+#define FRED_EVENT_VECTOR_COUNT                _BITUL(FRED_EVENT_VECTOR_BITS)
+
+/* FRED EVENT_TYPE_OTHER vector numbers */
+#define FRED_SYSCALL                   1
+#define FRED_SYSENTER                  2
+#define FRED_NUM_OTHER_VECTORS         3
+
+/* Flags above the SS selector (regs->ssx) */
+#define FRED_SSX_INTERRUPT_SHADOW_BIT  16
+#define FRED_SSX_INTERRUPT_SHADOW      _BITUL(FRED_SSX_INTERRUPT_SHADOW_BIT)
+#define FRED_SSX_SOFTWARE_INITIATED_BIT        17
+#define FRED_SSX_SOFTWARE_INITIATED    _BITUL(FRED_SSX_SOFTWARE_INITIATED_BIT)
+#define FRED_SSX_NMI_BIT               18
+#define FRED_SSX_NMI                   _BITUL(FRED_SSX_NMI_BIT)
+#define FRED_SSX_64_BIT_MODE_BIT       57
+#define FRED_SSX_64_BIT_MODE           _BITUL(FRED_SSX_64_BIT_MODE_BIT)
+
+#ifdef CONFIG_X86_FRED
+
+#ifndef __ASSEMBLY__
+
+#include <linux/kernel.h>
+#include <asm/ptrace.h>
+
+struct fred_info {
+       /* Event data: CR2, DR6, ... */
+       unsigned long edata;
+       unsigned long resv;
+};
+
+/* Full format of the FRED stack frame */
+struct fred_frame {
+       struct pt_regs   regs;
+       struct fred_info info;
+};
+
+static __always_inline struct fred_info *fred_info(struct pt_regs *regs)
+{
+       return &container_of(regs, struct fred_frame, regs)->info;
+}
+
+static __always_inline unsigned long fred_event_data(struct pt_regs *regs)
+{
+       return fred_info(regs)->edata;
+}
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* CONFIG_X86_FRED */
+
+#endif /* ASM_X86_FRED_H */
-- 
2.34.1