gdb: AArch64: Support MTE on baremetal

This commit moves aarch64_linux_memtag_matches_p,
aarch64_linux_set_memtags, aarch64_linux_get_memtag, and
aarch64_linux_memtag_to_string hooks (plus the aarch64_mte_get_atag
function used by them), along with the setting of the memtag granule
size, from aarch64-linux-tdep.c to aarch64-tdep.c, making MTE available
on baremetal targets. Since the aarch64-linux-tdep.c layer inherits
these hooks from aarch64-tdep.c, there is no effective change for
aarch64-linux targets.

Helpers used both by aarch64-tdep.c and by aarch64-linux-tdep.c were
moved from arch/aarch64-mte-linux.{c,h} to new arch/aarch64-mte.{c,h}
files.

Signed-off-by: Gustavo Romero <gustavo.romero@linaro.org>
Tested-By: Luis Machado <luis.machado@arm.com>
Approved-By: Luis Machado <luis.machado@arm.com>
Reviewed-By: Eli Zaretskii <eliz@gnu.org>

4 files changed, 128 insertions, 83 deletions

diff --git a/gdb/arch/aarch64-mte-linux.c b/gdb/arch/aarch64-mte-linux.c
index e0b441e..49426d7 100644
--- a/gdb/arch/aarch64-mte-linux.c
+++ b/gdb/arch/aarch64-mte-linux.c
@@ -75,59 +75,3 @@ aarch64_mte_unpack_tags (gdb::byte_vector &tags, bool skip_first)
   tags = std::move (unpacked_tags);
 }
 
-/* See arch/aarch64-mte-linux.h */
-
-size_t
-aarch64_mte_get_tag_granules (CORE_ADDR addr, size_t len, size_t granule_size)
-{
-  /* An empty range has 0 tag granules.  */
-  if (len == 0)
-    return 0;
-
-  /* Start address */
-  CORE_ADDR s_addr = align_down (addr, granule_size);
-  /* End address */
-  CORE_ADDR e_addr = align_down (addr + len - 1, granule_size);
-
-  /* We always have at least 1 granule because len is non-zero at this
-     point.  */
-  return 1 + (e_addr - s_addr) / granule_size;
-}
-
-/* See arch/aarch64-mte-linux.h */
-
-CORE_ADDR
-aarch64_mte_make_ltag_bits (CORE_ADDR value)
-{
-  return value & AARCH64_MTE_LOGICAL_MAX_VALUE;
-}
-
-/* See arch/aarch64-mte-linux.h */
-
-CORE_ADDR
-aarch64_mte_make_ltag (CORE_ADDR value)
-{
-  return (aarch64_mte_make_ltag_bits (value)
-	  << AARCH64_MTE_LOGICAL_TAG_START_BIT);
-}
-
-/* See arch/aarch64-mte-linux.h */
-
-CORE_ADDR
-aarch64_mte_set_ltag (CORE_ADDR address, CORE_ADDR tag)
-{
-  /* Remove the existing tag.  */
-  address &= ~aarch64_mte_make_ltag (AARCH64_MTE_LOGICAL_MAX_VALUE);
-
-  /* Return the new tagged address.  */
-  return address | aarch64_mte_make_ltag (tag);
-}
-
-/* See arch/aarch64-mte-linux.h */
-
-CORE_ADDR
-aarch64_mte_get_ltag (CORE_ADDR address)
-{
-  CORE_ADDR ltag_addr = address >> AARCH64_MTE_LOGICAL_TAG_START_BIT;
-  return aarch64_mte_make_ltag_bits (ltag_addr);
-}
diff --git a/gdb/arch/aarch64-mte-linux.h b/gdb/arch/aarch64-mte-linux.h
index 460b10e..686749f 100644
--- a/gdb/arch/aarch64-mte-linux.h
+++ b/gdb/arch/aarch64-mte-linux.h
@@ -29,12 +29,6 @@
 /* The MTE regset consists of a single 64-bit register.  */
 #define AARCH64_LINUX_SIZEOF_MTE 8
 
-/* We have one tag per 16 bytes of memory.  */
-#define AARCH64_MTE_GRANULE_SIZE 16
-#define AARCH64_MTE_TAG_BIT_SIZE 4
-#define AARCH64_MTE_LOGICAL_TAG_START_BIT 56
-#define AARCH64_MTE_LOGICAL_MAX_VALUE 0xf
-
 /* Memory tagging definitions.  */
 #ifndef SEGV_MTEAERR
 # define SEGV_MTEAERR 8
@@ -50,27 +44,6 @@ enum class aarch64_memtag_type
   mte_allocation
 };
 
-/* Return the number of tag granules in the memory range
-   [ADDR, ADDR + LEN) given GRANULE_SIZE.  */
-extern size_t aarch64_mte_get_tag_granules (CORE_ADDR addr, size_t len,
-					    size_t granule_size);
-
-/* Return the 4-bit tag made from VALUE.  */
-extern CORE_ADDR aarch64_mte_make_ltag_bits (CORE_ADDR value);
-
-/* Return the 4-bit tag that can be OR-ed to an address.  */
-extern CORE_ADDR aarch64_mte_make_ltag (CORE_ADDR value);
-
-/* Helper to set the logical TAG for a 64-bit ADDRESS.
-
-   It is always possible to set the logical tag.  */
-extern CORE_ADDR aarch64_mte_set_ltag (CORE_ADDR address, CORE_ADDR tag);
-
-/* Helper to get the logical tag from a 64-bit ADDRESS.
-
-   It is always possible to get the logical tag.  */
-extern CORE_ADDR aarch64_mte_get_ltag (CORE_ADDR address);
-
 /* Given a TAGS vector containing 1 MTE tag per byte, pack the data as
    2 tags per byte and resize the vector.  */
 extern void aarch64_mte_pack_tags (gdb::byte_vector &tags);
diff --git a/gdb/arch/aarch64-mte.c b/gdb/arch/aarch64-mte.c
new file mode 100644
index 0000000..908e12c
--- /dev/null
+++ b/gdb/arch/aarch64-mte.c
@@ -0,0 +1,77 @@
+/* Common AArch64 functionality for MTE
+
+   Copyright (C) 2021-2024 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 "arch/aarch64-mte.h"
+
+/* See arch/aarch64-mte.h */
+
+size_t
+aarch64_mte_get_tag_granules (CORE_ADDR addr, size_t len, size_t granule_size)
+{
+  /* An empty range has 0 tag granules.  */
+  if (len == 0)
+    return 0;
+
+  /* Start address */
+  CORE_ADDR s_addr = align_down (addr, granule_size);
+  /* End address */
+  CORE_ADDR e_addr = align_down (addr + len - 1, granule_size);
+
+  /* We always have at least 1 granule because len is non-zero at this
+     point.  */
+  return 1 + (e_addr - s_addr) / granule_size;
+}
+
+/* See arch/aarch64-mte.h */
+
+CORE_ADDR
+aarch64_mte_make_ltag_bits (CORE_ADDR value)
+{
+  return value & AARCH64_MTE_LOGICAL_MAX_VALUE;
+}
+
+/* See arch/aarch64-mte.h */
+
+CORE_ADDR
+aarch64_mte_make_ltag (CORE_ADDR value)
+{
+  return (aarch64_mte_make_ltag_bits (value)
+	  << AARCH64_MTE_LOGICAL_TAG_START_BIT);
+}
+
+/* See arch/aarch64-mte.h */
+
+CORE_ADDR
+aarch64_mte_set_ltag (CORE_ADDR address, CORE_ADDR tag)
+{
+  /* Remove the existing tag.  */
+  address &= ~aarch64_mte_make_ltag (AARCH64_MTE_LOGICAL_MAX_VALUE);
+
+  /* Return the new tagged address.  */
+  return address | aarch64_mte_make_ltag (tag);
+}
+
+/* See arch/aarch64-mte.h */
+
+CORE_ADDR
+aarch64_mte_get_ltag (CORE_ADDR address)
+{
+  CORE_ADDR ltag_addr = address >> AARCH64_MTE_LOGICAL_TAG_START_BIT;
+  return aarch64_mte_make_ltag_bits (ltag_addr);
+}
diff --git a/gdb/arch/aarch64-mte.h b/gdb/arch/aarch64-mte.h
new file mode 100644
index 0000000..7d8445e
--- /dev/null
+++ b/gdb/arch/aarch64-mte.h
@@ -0,0 +1,51 @@
+/* Common AArch64 definitions for MTE
+
+   Copyright (C) 2021-2024 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_AARCH64_MTE_H
+#define ARCH_AARCH64_MTE_H
+
+
+/* We have one tag per 16 bytes of memory.  */
+#define AARCH64_MTE_GRANULE_SIZE 16
+#define AARCH64_MTE_TAG_BIT_SIZE 4
+#define AARCH64_MTE_LOGICAL_TAG_START_BIT 56
+#define AARCH64_MTE_LOGICAL_MAX_VALUE 0xf
+
+/* Return the number of tag granules in the memory range
+   [ADDR, ADDR + LEN) given GRANULE_SIZE.  */
+extern size_t aarch64_mte_get_tag_granules (CORE_ADDR addr, size_t len,
+					    size_t granule_size);
+
+/* Return the 4-bit tag made from VALUE.  */
+extern CORE_ADDR aarch64_mte_make_ltag_bits (CORE_ADDR value);
+
+/* Return the 4-bit tag that can be OR-ed to an address.  */
+extern CORE_ADDR aarch64_mte_make_ltag (CORE_ADDR value);
+
+/* Helper to set the logical TAG for a 64-bit ADDRESS.
+
+   It is always possible to set the logical tag.  */
+extern CORE_ADDR aarch64_mte_set_ltag (CORE_ADDR address, CORE_ADDR tag);
+
+/* Helper to get the logical tag from a 64-bit ADDRESS.
+
+   It is always possible to get the logical tag.  */
+extern CORE_ADDR aarch64_mte_get_ltag (CORE_ADDR address);
+
+#endif /* ARCH_AARCH64_MTE_H */