Convert SVE macros into c++ constants and inlines

This patch updates LLDB's in house version of SVE ptrace/sig macros by
converting them into constants and inlines. They are housed under sve
namespace and are used by process elf-core for reading SVE register data.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D85641

Author: omjavaid

lldb/source/Plugins/Process/Utility/LinuxPTraceDefines_arm64sve.h

@@ -9,60 +9,57 @@
 #ifndef LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_LINUXPTRACEDEFINES_ARM64SVE_H
 #define LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_LINUXPTRACEDEFINES_ARM64SVE_H
 
-// LinuxPTraceDefines_arm64sve.h defines essential macros for manipulating
-// AArch64 SVE core dump registers. Add guard for aarch64/Linux hosts where
-// newer versions of ptrace.h or sigcontext.h might already define SVE macros.
-#ifndef SVE_SIG_REGS_OFFSET
-
 #include <stdint.h>
 
-struct aarch64_context {
-  uint16_t magic;
-  uint16_t size;
-};
-
-#define SVE_MAGIC 0x53564501
-
-struct sve_context {
-  struct aarch64_context head;
-  uint16_t vl;
-  uint16_t reserved[3];
-};
+namespace lldb_private {
+namespace sve {
 
 /*
  * The SVE architecture leaves space for future expansion of the
  * vector length beyond its initial architectural limit of 2048 bits
  * (16 quadwords).
  *
- * See linux/Documentation/arm64/sve.txt for a description of the VL/VQ
- * terminology.
+ * See <Linux kernel source tree>/Documentation/arm64/sve.rst for a description
+ * of the vl/vq terminology.
  */
-#define SVE_VQ_BYTES 16 /* number of bytes per quadword */
 
-#define SVE_VQ_MIN 1
-#define SVE_VQ_MAX 512
+const uint16_t vq_bytes = 16; /* number of bytes per quadword */
+
+const uint16_t vq_min = 1;
+const uint16_t vq_max = 512;
+
+const uint16_t vl_min = vq_min * vq_bytes;
+const uint16_t vl_max = vq_max * vq_bytes;
 
-#define SVE_VL_MIN (SVE_VQ_MIN * SVE_VQ_BYTES)
-#define SVE_VL_MAX (SVE_VQ_MAX * SVE_VQ_BYTES)
+const uint16_t num_of_zregs = 32;
+const uint16_t num_of_pregs = 16;
 
-#define SVE_NUM_ZREGS 32
-#define SVE_NUM_PREGS 16
+inline uint16_t vl_valid(uint16_t vl) {
+  return (vl % vq_bytes == 0 && vl >= vl_min && vl <= vl_max);
+}
 
-#define sve_vl_valid(vl)                                                       \
-  ((vl) % SVE_VQ_BYTES == 0 && (vl) >= SVE_VL_MIN && (vl) <= SVE_VL_MAX)
-#define sve_vq_from_vl(vl) ((vl) / SVE_VQ_BYTES)
-#define sve_vl_from_vq(vq) ((vq)*SVE_VQ_BYTES)
+inline uint16_t vq_from_vl(uint16_t vl) { return vl / vq_bytes; }
+inline uint16_t vl_from_vq(uint16_t vq) { return vq * vq_bytes; }
+
+/* A new signal frame record sve_context encodes the SVE Registers on signal
+ * delivery. sve_context struct definition may be included in asm/sigcontext.h.
+ * We define sve_context_size which will be used by LLDB sve helper functions.
+ * More information on sve_context can be found in Linux kernel source tree at
+ * Documentation/arm64/sve.rst.
+ */
+
+const uint16_t sve_context_size = 16;
 
 /*
  * If the SVE registers are currently live for the thread at signal delivery,
  * sve_context.head.size >=
- *	SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl))
- * and the register data may be accessed using the SVE_SIG_*() macros.
+ * SigContextSize(vq_from_vl(sve_context.vl))
+ * and the register data may be accessed using the Sig*() functions.
  *
  * If sve_context.head.size <
- *	SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl)),
+ * SigContextSize(vq_from_vl(sve_context.vl)),
  * the SVE registers were not live for the thread and no register data
- * is included: in this case, the SVE_SIG_*() macros should not be
+ * is included: in this case, the Sig*() functions should not be
  * used except for this check.
  *
  * The same convention applies when returning from a signal: a caller
@@ -76,63 +73,75 @@ struct sve_context {
  * doing a sigreturn.
  *
  *
- * Note: for all these macros, the "vq" argument denotes the SVE
+ * Note: for all these functions, the "vq" argument denotes the SVE
  * vector length in quadwords (i.e., units of 128 bits).
  *
- * The correct way to obtain vq is to use sve_vq_from_vl(vl).  The
- * result is valid if and only if sve_vl_valid(vl) is true.  This is
+ * The correct way to obtain vq is to use vq_from_vl(vl).  The
+ * result is valid if and only if vl_valid(vl) is true.  This is
  * guaranteed for a struct sve_context written by the kernel.
  *
  *
- * Additional macros describe the contents and layout of the payload.
- * For each, SVE_SIG_x_OFFSET(args) is the start offset relative to
- * the start of struct sve_context, and SVE_SIG_x_SIZE(args) is the
+ * Additional functions describe the contents and layout of the payload.
+ * For each, Sig*Offset(args) is the start offset relative to
+ * the start of struct sve_context, and Sig*Size(args) is the
  * size in bytes:
  *
  *	x	type				description
  *	-	----				-----------
  *	REGS					the entire SVE context
  *
- *	ZREGS	__uint128_t[SVE_NUM_ZREGS][vq]	all Z-registers
+ *	ZREGS	__uint128_t[num_of_zregs][vq]	all Z-registers
  *	ZREG	__uint128_t[vq]			individual Z-register Zn
  *
- *	PREGS	uint16_t[SVE_NUM_PREGS][vq]	all P-registers
+ *	PREGS	uint16_t[num_of_pregs][vq]	all P-registers
  *	PREG	uint16_t[vq]			individual P-register Pn
  *
  *	FFR	uint16_t[vq]			first-fault status register
  *
  * Additional data might be appended in the future.
  */
 
-#define SVE_SIG_ZREG_SIZE(vq) ((uint32_t)(vq)*SVE_VQ_BYTES)
-#define SVE_SIG_PREG_SIZE(vq) ((uint32_t)(vq) * (SVE_VQ_BYTES / 8))
-#define SVE_SIG_FFR_SIZE(vq) SVE_SIG_PREG_SIZE(vq)
+inline uint16_t SigZRegSize(uint16_t vq) { return vq * vq_bytes; }
+inline uint16_t SigPRegSize(uint16_t vq) { return vq * vq_bytes / 8; }
+inline uint16_t SigFFRSize(uint16_t vq) { return SigPRegSize(vq); }
+
+inline uint32_t SigRegsOffset() {
+  return (sve_context_size + vq_bytes - 1) / vq_bytes * vq_bytes;
+}
+
+inline uint32_t SigZRegsOffset() { return SigRegsOffset(); }
+
+inline uint32_t SigZRegOffset(uint16_t vq, uint16_t n) {
+  return SigRegsOffset() + SigZRegSize(vq) * n;
+}
 
-#define SVE_SIG_REGS_OFFSET                                                    \
-  ((sizeof(struct sve_context) + (SVE_VQ_BYTES - 1)) / SVE_VQ_BYTES *          \
-   SVE_VQ_BYTES)
+inline uint32_t SigZRegsSize(uint16_t vq) {
+  return SigZRegOffset(vq, num_of_zregs) - SigRegsOffset();
+}
 
-#define SVE_SIG_ZREGS_OFFSET SVE_SIG_REGS_OFFSET
-#define SVE_SIG_ZREG_OFFSET(vq, n)                                             \
-  (SVE_SIG_ZREGS_OFFSET + SVE_SIG_ZREG_SIZE(vq) * (n))
-#define SVE_SIG_ZREGS_SIZE(vq)                                                 \
-  (SVE_SIG_ZREG_OFFSET(vq, SVE_NUM_ZREGS) - SVE_SIG_ZREGS_OFFSET)
+inline uint32_t SigPRegsOffset(uint16_t vq) {
+  return SigRegsOffset() + SigZRegsSize(vq);
+}
 
-#define SVE_SIG_PREGS_OFFSET(vq) (SVE_SIG_ZREGS_OFFSET + SVE_SIG_ZREGS_SIZE(vq))
-#define SVE_SIG_PREG_OFFSET(vq, n)                                             \
-  (SVE_SIG_PREGS_OFFSET(vq) + SVE_SIG_PREG_SIZE(vq) * (n))
-#define SVE_SIG_PREGS_SIZE(vq)                                                 \
-  (SVE_SIG_PREG_OFFSET(vq, SVE_NUM_PREGS) - SVE_SIG_PREGS_OFFSET(vq))
+inline uint32_t SigPRegOffset(uint16_t vq, uint16_t n) {
+  return SigPRegsOffset(vq) + SigPRegSize(vq) * n;
+}
 
-#define SVE_SIG_FFR_OFFSET(vq)                                                 \
-  (SVE_SIG_PREGS_OFFSET(vq) + SVE_SIG_PREGS_SIZE(vq))
+inline uint32_t SigpRegsSize(uint16_t vq) {
+  return SigPRegOffset(vq, num_of_pregs) - SigPRegsOffset(vq);
+}
 
-#define SVE_SIG_REGS_SIZE(vq)                                                  \
-  (SVE_SIG_FFR_OFFSET(vq) + SVE_SIG_FFR_SIZE(vq) - SVE_SIG_REGS_OFFSET)
+inline uint32_t SigFFROffset(uint16_t vq) {
+  return SigPRegsOffset(vq) + SigpRegsSize(vq);
+}
 
-#define SVE_SIG_CONTEXT_SIZE(vq) (SVE_SIG_REGS_OFFSET + SVE_SIG_REGS_SIZE(vq))
+inline uint32_t SigRegsSize(uint16_t vq) {
+  return SigFFROffset(vq) + SigFFRSize(vq) - SigRegsOffset();
+}
 
-/* SVE/FP/SIMD state (NT_ARM_SVE) */
+inline uint32_t SVESigContextSize(uint16_t vq) {
+  return SigRegsOffset() + SigRegsSize(vq);
+}
 
 struct user_sve_header {
   uint32_t size;     /* total meaningful regset content in bytes */
@@ -144,61 +153,54 @@ struct user_sve_header {
 };
 
 /* Definitions for user_sve_header.flags: */
-#define SVE_PT_REGS_MASK (1 << 0)
-
-#define SVE_PT_REGS_FPSIMD 0
-#define SVE_PT_REGS_SVE SVE_PT_REGS_MASK
-
-/*
- * Common SVE_PT_* flags:
- * These must be kept in sync with prctl interface in <linux/ptrace.h>
- */
-#define SVE_PT_VL_INHERIT (PR_SVE_VL_INHERIT >> 16)
-#define SVE_PT_VL_ONEXEC (PR_SVE_SET_VL_ONEXEC >> 16)
+const uint16_t ptrace_regs_mask = 1 << 0;
+const uint16_t ptrace_regs_fpsimd = 0;
+const uint16_t ptrace_regs_sve = ptrace_regs_mask;
 
 /*
  * The remainder of the SVE state follows struct user_sve_header.  The
  * total size of the SVE state (including header) depends on the
- * metadata in the header:  SVE_PT_SIZE(vq, flags) gives the total size
+ * metadata in the header:  PTraceSize(vq, flags) gives the total size
  * of the state in bytes, including the header.
  *
  * Refer to <asm/sigcontext.h> for details of how to pass the correct
  * "vq" argument to these macros.
  */
 
 /* Offset from the start of struct user_sve_header to the register data */
-#define SVE_PT_REGS_OFFSET                                                     \
-  ((sizeof(struct sve_context) + (SVE_VQ_BYTES - 1)) / SVE_VQ_BYTES *          \
-   SVE_VQ_BYTES)
+inline uint16_t PTraceRegsOffset() {
+  return (sizeof(struct user_sve_header) + vq_bytes - 1) / vq_bytes * vq_bytes;
+}
 
 /*
  * The register data content and layout depends on the value of the
  * flags field.
  */
 
 /*
- * (flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD case:
+ * (flags & ptrace_regs_mask) == ptrace_regs_fpsimd case:
  *
- * The payload starts at offset SVE_PT_FPSIMD_OFFSET, and is of type
+ * The payload starts at offset PTraceFPSIMDOffset, and is of type
  * struct user_fpsimd_state.  Additional data might be appended in the
- * future: use SVE_PT_FPSIMD_SIZE(vq, flags) to compute the total size.
- * SVE_PT_FPSIMD_SIZE(vq, flags) will never be less than
+ * future: use PTraceFPSIMDSize(vq, flags) to compute the total size.
+ * PTraceFPSIMDSize(vq, flags) will never be less than
  * sizeof(struct user_fpsimd_state).
  */
 
-#define SVE_PT_FPSIMD_OFFSET SVE_PT_REGS_OFFSET
+const uint32_t ptrace_fpsimd_offset = PTraceRegsOffset();
 
-#define SVE_PT_FPSIMD_SIZE(vq, flags) (sizeof(struct user_fpsimd_state))
+/* Return size of struct user_fpsimd_state from asm/ptrace.h */
+inline uint32_t PTraceFPSIMDSize(uint16_t vq, uint16_t flags) { return 528; }
 
 /*
- * (flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_SVE case:
+ * (flags & ptrace_regs_mask) == ptrace_regs_sve case:
  *
- * The payload starts at offset SVE_PT_SVE_OFFSET, and is of size
- * SVE_PT_SVE_SIZE(vq, flags).
+ * The payload starts at offset PTraceSVEOffset, and is of size
+ * PTraceSVESize(vq, flags).
  *
- * Additional macros describe the contents and layout of the payload.
- * For each, SVE_PT_SVE_x_OFFSET(args) is the start offset relative to
- * the start of struct user_sve_header, and SVE_PT_SVE_x_SIZE(args) is
+ * Additional functions describe the contents and layout of the payload.
+ * For each, PTrace*X*Offset(args) is the start offset relative to
+ * the start of struct user_sve_header, and PTrace*X*Size(args) is
  * the size in bytes:
  *
  *	x	type				description
@@ -215,53 +217,75 @@ struct user_sve_header {
  * Additional data might be appended in the future.
  */
 
-#define SVE_PT_SVE_ZREG_SIZE(vq) SVE_SIG_ZREG_SIZE(vq)
-#define SVE_PT_SVE_PREG_SIZE(vq) SVE_SIG_PREG_SIZE(vq)
-#define SVE_PT_SVE_FFR_SIZE(vq) SVE_SIG_FFR_SIZE(vq)
-#define SVE_PT_SVE_FPSR_SIZE sizeof(uint32_t)
-#define SVE_PT_SVE_FPCR_SIZE sizeof(uint32_t)
+inline uint32_t PTraceZRegSize(uint16_t vq) { return SigZRegSize(vq); }
+
+inline uint32_t PTracePRegSize(uint16_t vq) { return SigPRegSize(vq); }
+
+inline uint32_t PTraceFFRSize(uint16_t vq) { return SigFFRSize(vq); }
+
+const uint32_t fpsr_size = sizeof(uint32_t);
+const uint32_t fpcr_size = sizeof(uint32_t);
+
+inline uint32_t SigToPTrace(uint32_t offset) {
+  return offset - SigRegsOffset() + PTraceRegsOffset();
+}
+
+const uint32_t ptrace_sve_offset = PTraceRegsOffset();
+
+inline uint32_t PTraceZRegsOffset(uint16_t vq) {
+  return SigToPTrace(SigZRegsOffset());
+}
+
+inline uint32_t PTraceZRegOffset(uint16_t vq, uint16_t n) {
+  return SigToPTrace(SigZRegOffset(vq, n));
+}
+
+inline uint32_t PTraceZRegsSize(uint16_t vq) {
+  return PTraceZRegOffset(vq, num_of_zregs) - SigToPTrace(SigRegsOffset());
+}
 
-#define __SVE_SIG_TO_PT(offset)                                                \
-  ((offset)-SVE_SIG_REGS_OFFSET + SVE_PT_REGS_OFFSET)
+inline uint32_t PTracePRegsOffset(uint16_t vq) {
+  return SigToPTrace(SigPRegsOffset(vq));
+}
 
-#define SVE_PT_SVE_OFFSET SVE_PT_REGS_OFFSET
+inline uint32_t PTracePRegOffset(uint16_t vq, uint16_t n) {
+  return SigToPTrace(SigPRegOffset(vq, n));
+}
 
-#define SVE_PT_SVE_ZREGS_OFFSET __SVE_SIG_TO_PT(SVE_SIG_ZREGS_OFFSET)
-#define SVE_PT_SVE_ZREG_OFFSET(vq, n)                                          \
-  __SVE_SIG_TO_PT(SVE_SIG_ZREG_OFFSET(vq, n))
-#define SVE_PT_SVE_ZREGS_SIZE(vq)                                              \
-  (SVE_PT_SVE_ZREG_OFFSET(vq, SVE_NUM_ZREGS) - SVE_PT_SVE_ZREGS_OFFSET)
+inline uint32_t PTracePRegsSize(uint16_t vq) {
+  return PTracePRegOffset(vq, num_of_pregs) - PTracePRegsOffset(vq);
+}
 
-#define SVE_PT_SVE_PREGS_OFFSET(vq) __SVE_SIG_TO_PT(SVE_SIG_PREGS_OFFSET(vq))
-#define SVE_PT_SVE_PREG_OFFSET(vq, n)                                          \
-  __SVE_SIG_TO_PT(SVE_SIG_PREG_OFFSET(vq, n))
-#define SVE_PT_SVE_PREGS_SIZE(vq)                                              \
-  (SVE_PT_SVE_PREG_OFFSET(vq, SVE_NUM_PREGS) - SVE_PT_SVE_PREGS_OFFSET(vq))
+inline uint32_t PTraceFFROffset(uint16_t vq) {
+  return SigToPTrace(SigFFROffset(vq));
+}
 
-#define SVE_PT_SVE_FFR_OFFSET(vq) __SVE_SIG_TO_PT(SVE_SIG_FFR_OFFSET(vq))
+inline uint32_t PTraceFPSROffset(uint16_t vq) {
+  return (PTraceFFROffset(vq) + PTraceFFRSize(vq) + (vq_bytes - 1)) / vq_bytes *
+         vq_bytes;
+}
 
-#define SVE_PT_SVE_FPSR_OFFSET(vq)                                             \
-  ((SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq) +                      \
-    (SVE_VQ_BYTES - 1)) /                                                      \
-   SVE_VQ_BYTES * SVE_VQ_BYTES)
-#define SVE_PT_SVE_FPCR_OFFSET(vq)                                             \
-  (SVE_PT_SVE_FPSR_OFFSET(vq) + SVE_PT_SVE_FPSR_SIZE)
+inline uint32_t PTraceFPCROffset(uint16_t vq) {
+  return PTraceFPSROffset(vq) + fpsr_size;
+}
 
 /*
  * Any future extension appended after FPCR must be aligned to the next
  * 128-bit boundary.
  */
 
-#define SVE_PT_SVE_SIZE(vq, flags)                                             \
-  ((SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE - SVE_PT_SVE_OFFSET +    \
-    (SVE_VQ_BYTES - 1)) /                                                      \
-   SVE_VQ_BYTES * SVE_VQ_BYTES)
+inline uint32_t PTraceSVESize(uint16_t vq, uint16_t flags) {
+  return (PTraceFPCROffset(vq) + fpcr_size - ptrace_sve_offset + vq_bytes - 1) /
+         vq_bytes * vq_bytes;
+}
 
-#define SVE_PT_SIZE(vq, flags)                                                 \
-  (((flags)&SVE_PT_REGS_MASK) == SVE_PT_REGS_SVE                               \
-       ? SVE_PT_SVE_OFFSET + SVE_PT_SVE_SIZE(vq, flags)                        \
-       : SVE_PT_FPSIMD_OFFSET + SVE_PT_FPSIMD_SIZE(vq, flags))
+inline uint32_t PTraceSize(uint16_t vq, uint16_t flags) {
+  return (flags & ptrace_regs_mask) == ptrace_regs_sve
+             ? ptrace_sve_offset + PTraceSVESize(vq, flags)
+             : ptrace_fpsimd_offset + PTraceFPSIMDSize(vq, flags);
+}
 
-#endif // SVE_SIG_REGS_OFFSET
+} // namespace SVE
+} // namespace lldb_private
 
 #endif // LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_LINUXPTRACEDEFINES_ARM64SVE_H