[PATCH v2 05/47] gdb, arch, intelgt: add intelgt arch definitions

[Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>]

From: Markus Metzger <markus.t.metzger@intel.com>

Provide Intel GT architecture-specific definitions that can be used by
both the low target at the server side and tdep at the GDB side.

Other than, for example, IA, Intel GT does not have a dedicated
breakpoint instruction.  Instead, it has a breakpoint bit in each
instruction.  We define arch methods for dealing with instruction
breakpoint bits.

Co-authored-by: Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>
Co-authored-by: Mihails Strasuns <mihails.strasuns@intel.com>
Co-authored-by: Natalia Saiapova <natalia.saiapova@intel.com>
---
 gdb/Makefile.in    |   1 +
 gdb/arch/intelgt.c |  77 +++++++++++++++++++++++
 gdb/arch/intelgt.h | 175 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 253 insertions(+)

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 52950759711af139f18e963b13fef7e70a5fc6e0..82e035fa02a29ec073c3a909397aca75d82e4a89 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -751,6 +751,7 @@ ALL_64_TARGET_OBS = \
 	arch/aarch64-scalable-linux.o \
 	arch/amd64-linux-tdesc.o \
 	arch/amd64.o \
+	arch/intelgt.o \
 	arch/riscv.o \
 	bpf-tdep.o \
 	ia64-linux-tdep.o \
diff --git a/gdb/arch/intelgt.c b/gdb/arch/intelgt.c
new file mode 100644
index 0000000000000000000000000000000000000000..89a19baea8428c1479d1e43de676a4f0dfb01952
--- /dev/null
+++ b/gdb/arch/intelgt.c
@@ -0,0 +1,77 @@
+/* Copyright (C) 2019-2024 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "intelgt.h"
+#include <stdlib.h>
+
+namespace intelgt {
+
+/* Get the bit at POS in INST.  */
+
+bool
+get_inst_bit (gdb::array_view<const gdb_byte> inst, int pos)
+{
+  if (pos < 0 || (inst.size () * 8) <= pos)
+    internal_error (_("bad bit offset: %d"), pos);
+
+  const int idx = pos >> 3;
+  const int off = pos & 7;
+  const int mask = 1 << off;
+  const gdb_byte byte = inst[idx];
+
+  return (byte & mask) != 0;
+}
+
+/* Set the bit at POS in INST.  */
+
+bool
+set_inst_bit (gdb::array_view<gdb_byte> inst, int pos)
+{
+  if (pos < 0 || (inst.size () * 8) <= pos)
+    internal_error (_("bad bit offset: %d"), pos);
+
+  const int idx = pos >> 3;
+  const int off = pos & 7;
+  const int mask = 1 << off;
+  const gdb_byte byte = inst[idx];
+
+  const bool old = (byte & mask) != 0;
+  inst[idx] |= mask;
+
+  return old;
+}
+
+/* Clear the bit at POS in INST.  */
+
+bool
+clear_inst_bit (gdb::array_view<gdb_byte> inst, int pos)
+{
+  if (pos < 0 || (inst.size () * 8) <= pos)
+    internal_error (_("bad bit offset: %d"), pos);
+
+  const int idx = pos >> 3;
+  const int off = pos & 7;
+  const int mask = 1 << off;
+  const gdb_byte byte = inst[idx];
+
+  const bool old = (byte & mask) != 0;
+  inst[idx] &= ~mask;
+
+  return old;
+}
+
+} /* namespace intelgt */
diff --git a/gdb/arch/intelgt.h b/gdb/arch/intelgt.h
new file mode 100644
index 0000000000000000000000000000000000000000..38e89053a9b22e26c370525758f8da7f3790f6bb
--- /dev/null
+++ b/gdb/arch/intelgt.h
@@ -0,0 +1,175 @@
+/* Copyright (C) 2019-2024 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#ifndef ARCH_INTELGT_H
+#define ARCH_INTELGT_H
+
+#include "gdbsupport/tdesc.h"
+#include <string>
+#include <vector>
+
+namespace intelgt {
+
+/* Various arch constants.  */
+
+enum breakpoint_kind
+{
+  BP_INSTRUCTION = 1,
+};
+
+/* The length of a full and compact IntelGT instruction in bytes.  */
+
+constexpr int MAX_INST_LENGTH = 16;
+constexpr int COMPACT_INST_LENGTH = 8;
+
+/* Feature names.
+
+   They correspond to register sets defined in zet_intel_gpu_debug.h.  We
+   declare feature names in the order used in that header.
+
+   The SBA register set consists of a set of base registers in the order
+   defined in that header file.
+
+   Not all registers have DWARF numbers.  See DWARF_REGSETS below for a
+   list of features that do.  */
+constexpr const char *FEATURE_GRF = "org.gnu.gdb.intelgt.grf";
+constexpr const char *FEATURE_ADDR = "org.gnu.gdb.intelgt.addr";
+constexpr const char *FEATURE_FLAG = "org.gnu.gdb.intelgt.flag";
+constexpr const char *FEATURE_CE = "org.gnu.gdb.intelgt.ce";
+constexpr const char *FEATURE_SR = "org.gnu.gdb.intelgt.sr";
+constexpr const char *FEATURE_CR = "org.gnu.gdb.intelgt.cr";
+constexpr const char *FEATURE_TDR = "org.gnu.gdb.intelgt.tdr";
+constexpr const char *FEATURE_ACC = "org.gnu.gdb.intelgt.acc";
+constexpr const char *FEATURE_MME = "org.gnu.gdb.intelgt.mme";
+constexpr const char *FEATURE_SP = "org.gnu.gdb.intelgt.sp";
+constexpr const char *FEATURE_SBA = "org.gnu.gdb.intelgt.sba";
+constexpr const char *FEATURE_DBG = "org.gnu.gdb.intelgt.dbg";
+constexpr const char *FEATURE_FC = "org.gnu.gdb.intelgt.fc";
+constexpr const char *FEATURE_DEBUGGER = "org.gnu.gdb.intelgt.debugger";
+
+/* Register sets/groups needed for DWARF mapping.  Used for
+   declaring static arrays for various mapping tables.  */
+
+enum dwarf_regsets : int
+{
+  REGSET_SBA = 0,
+  REGSET_GRF,
+  REGSET_ADDR,
+  REGSET_FLAG,
+  REGSET_ACC,
+  REGSET_MME,
+  REGSET_COUNT
+};
+
+/* Map of dwarf_regset values to the target description
+   feature names.  */
+
+constexpr const char *DWARF_REGSET_FEATURES[REGSET_COUNT] = {
+  FEATURE_SBA,
+  FEATURE_GRF,
+  FEATURE_ADDR,
+  FEATURE_FLAG,
+  FEATURE_ACC,
+  FEATURE_MME
+};
+
+/* Instruction details.  */
+
+enum
+{
+  /* The opcode mask for bits 6:0.  */
+  OPC_MASK = 0x7f,
+
+  /* Send instruction opcodes.  */
+  OPC_SEND = 0x31,
+  OPC_SENDC = 0x32,
+};
+
+/* Selected instruction control bit positions.  */
+
+enum
+{
+  /* The End Of Thread control.  Only used for SEND and SENDC.  */
+  CTRL_EOT = 34,
+};
+
+/* Get the bit at POS in INST.  */
+
+bool get_inst_bit (gdb::array_view<const gdb_byte> inst, int pos);
+
+/* Set the bit at POS in INST.  */
+
+bool set_inst_bit (gdb::array_view<gdb_byte> inst, int pos);
+
+/* Clear the bit at POS in INST.  */
+
+bool clear_inst_bit (gdb::array_view<gdb_byte> inst, int pos);
+
+static inline bool
+is_compacted_inst (gdb::array_view<const gdb_byte> inst)
+{
+  /* Check the CmptCtrl flag (bit 29).  */
+  return inst[3] & 0x20;
+}
+
+static inline int
+breakpoint_bit_offset (gdb::array_view<const gdb_byte> inst)
+{
+  return (is_compacted_inst (inst) ? 7 : 30);
+}
+
+static inline bool
+set_breakpoint (gdb::array_view<gdb_byte> inst)
+{
+  return set_inst_bit (inst, breakpoint_bit_offset (inst));
+}
+
+static inline bool
+clear_breakpoint (gdb::array_view<gdb_byte> inst)
+{
+  return clear_inst_bit (inst, breakpoint_bit_offset (inst));
+}
+
+static inline bool
+has_breakpoint (gdb::array_view<const gdb_byte> inst)
+{
+  return get_inst_bit (inst, breakpoint_bit_offset (inst));
+}
+
+static inline unsigned int
+inst_length_compacted ()
+{
+  return COMPACT_INST_LENGTH;
+}
+
+static inline unsigned int
+inst_length_full ()
+{
+  return MAX_INST_LENGTH;
+}
+
+static inline unsigned int
+inst_length (gdb::array_view<const gdb_byte> inst)
+{
+  return (is_compacted_inst (inst)
+	  ? inst_length_compacted ()
+	  : inst_length_full ());
+}
+
+} /* namespace intelgt */
+
+#endif

-- 
2.34.1

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