[PowerPC] Add support for TAR

This patch adds support for the Target Address Register for powerpc
linux native and core file targets, and in the powerpc linux server
stub.

gdb/ChangeLog:
2018-10-26  Edjunior Barbosa Machado  <emachado@linux.vnet.ibm.com>
	    Pedro Franco de Carvalho  <pedromfc@linux.ibm.com>

	* arch/ppc-linux-tdesc.h (tdesc_powerpc_isa207_vsx32l)
	(tdesc_powerpc_isa207_vsx64l): Declare.
	* arch/ppc-linux-common.h (PPC_LINUX_SIZEOF_TARREGSET): Define.
	(struct ppc_linux_features) <isa207>: New field.
	(ppc_linux_no_features): Add initializer for isa207 field.
	* arch/ppc-linux-common.c (ppc_linux_match_description): Return
	new tdescs.
	* nat/ppc-linux.h (PPC_FEATURE2_ARCH_2_07, PPC_FEATURE2_TAR)
	(NT_PPC_TAR): Define if not already defined.
	* features/Makefile (WHICH): Add rs6000/powerpc-isa207-vsx32l and
	rs6000/powerpc-isa207-vsx64l.
	(XMLTOC): Add rs6000/powerpc-isa207-vsx32l.xml and
	rs6000/powerpc-isa207-vsx64l.xml.
	* features/rs6000/power-tar.xml: New file.
	* features/rs6000/powerpc-isa207-vsx32l.xml: New file.
	* features/rs6000/powerpc-isa207-vsx64l.xml: New file.
	* features/rs6000/powerpc-isa207-vsx32l.c: Generate.
	* features/rs6000/powerpc-isa207-vsx64l.c: Generate.
	* regformats/rs6000/powerpc-isa207-vsx32l.dat: Generate.
	* regformats/rs6000/powerpc-isa207-vsx64l.dat: Generate.
	* ppc-linux-nat.c (fetch_register, fetch_ppc_registers): Call
	fetch_regset with the TAR regset.
	(store_register, store_ppc_registers): Call store_regset with the
	TAR regset.
	(ppc_linux_nat_target::read_description): Set isa207 field in the
	features struct if needed.
	* ppc-linux-tdep.c: Include
	features/rs6000/powerpc-isa207-vsx32l.c and
	features/rs6000/powerpc-isa207-vsx64l.c.
	(ppc32_regmap_tar, ppc32_linux_tarregset): New globals.
	(ppc_linux_iterate_over_regset_sections): Call back with the tar
	regset.
	(ppc_linux_core_read_description): Check if the tar section is
	present and set isa207 in the features struct.
	(_initialize_ppc_linux_tdep): Call
	initialize_tdesc_powerpc_isa207_vsx32l and
	initialize_tdesc_powerpc_isa207_vsx64l.
	* ppc-linux-tdep.h (ppc32_linux_tarregset): Declare.
	* ppc-tdep.h (gdbarch_tdep) <ppc_tar_regnum>: New field.
	(enum) <PPC_TAR_REGNUM>: New enum value.
	* rs6000-tdep.c (rs6000_gdbarch_init): Look for and validate tar
	feature.
	(ppc_process_record_op31): Record changes to TAR.

gdb/gdbserver/ChangeLog:
2018-10-26  Pedro Franco de Carvalho  <pedromfc@linux.ibm.com>

	* configure.srv (ipa_ppc_linux_regobj): Add
	powerpc-isa207-vsx64l-ipa.o and powerpc-isa207-vsx32l-ipa.o.
	(powerpc*-*-linux*): Add powerpc-isa207-vsx32l.o and
	powerpc-isa207-vsx64l.o to srv_regobj, add rs6000/power-tar.xml,
	rs6000/powerpc-isa207-vsx32l.xml, and
	rs6000/powerpc-isa207-vsx64l.xml to srv_xmlfiles.
	* linux-ppc-tdesc-init.h (enum ppc_linux_tdesc)
	<PPC_TDESC_ISA207_VSX>: New enum value.
	(init_registers_powerpc_isa207_vsx32l): Declare.
	(init_registers_powerpc_isa207_vsx64l): Declare.
	* linux-ppc-low.c (ppc_fill_tarregset): New function.
	(ppc_store_tarregset): New function.
	(ppc_regsets): Add entry for the TAR regset.
	(ppc_arch_setup): Set isa207 in features struct when needed.  Set
	size for the TAR regsets.
	(ppc_get_ipa_tdesc_idx): Return PPC_TDESC_ISA207_VSX.
	(initialize_low_arch): Call init_registers_powerpc_isa207_vsx32l
	and init_registers_powerpc_isa207_vsx64l.
	* linux-ppc-ipa.c (get_ipa_tdesc): Handle PPC_TDESC_ISA207_VSX.
	(initialize_low_tracepoint): Call
	init_registers_powerpc_isa207_vsx32l and
	init_registers_powerpc_isa207_vsx64l.

gdb/testsuite/ChangeLog:
2018-10-26  Pedro Franco de Carvalho  <pedromfc@linux.ibm.com>

	* gdb.arch/powerpc-tar.c: New file.
	* gdb.arch/powerpc-tar.exp: New file.

gdb/doc/ChangeLog:
2018-10-26  Pedro Franco de Carvalho  <pedromfc@linux.ibm.com>

	* gdb.texinfo (PowerPC Features): Describe new feature
	"org.gnu.gdb.power.tar".

1 files changed, 33 insertions, 1 deletions

diff --git a/gdb/ppc-linux-nat.c b/gdb/ppc-linux-nat.c
index 27c73c2..850d229 100644
--- a/gdb/ppc-linux-nat.c
+++ b/gdb/ppc-linux-nat.c
@@ -657,6 +657,15 @@ fetch_register (struct regcache *regcache, int tid, int regno)
 		    &ppc32_linux_pprregset);
       return;
     }
+  else if (regno == PPC_TAR_REGNUM)
+    {
+      gdb_assert (tdep->ppc_tar_regnum != -1);
+
+      fetch_regset (regcache, tid, NT_PPC_TAR,
+		    PPC_LINUX_SIZEOF_TARREGSET,
+		    &ppc32_linux_tarregset);
+      return;
+    }
 
   if (regaddr == -1)
     {
@@ -858,6 +867,10 @@ fetch_ppc_registers (struct regcache *regcache, int tid)
     fetch_regset (regcache, tid, NT_PPC_DSCR,
 		  PPC_LINUX_SIZEOF_DSCRREGSET,
 		  &ppc32_linux_dscrregset);
+  if (tdep->ppc_tar_regnum != -1)
+    fetch_regset (regcache, tid, NT_PPC_TAR,
+		  PPC_LINUX_SIZEOF_TARREGSET,
+		  &ppc32_linux_tarregset);
 }
 
 /* Fetch registers from the child process.  Fetch all registers if
@@ -1056,6 +1069,15 @@ store_register (const struct regcache *regcache, int tid, int regno)
 		    &ppc32_linux_pprregset);
       return;
     }
+  else if (regno == PPC_TAR_REGNUM)
+    {
+      gdb_assert (tdep->ppc_tar_regnum != -1);
+
+      store_regset (regcache, tid, regno, NT_PPC_TAR,
+		    PPC_LINUX_SIZEOF_TARREGSET,
+		    &ppc32_linux_tarregset);
+      return;
+    }
 
   if (regaddr == -1)
     return;
@@ -1275,6 +1297,10 @@ store_ppc_registers (const struct regcache *regcache, int tid)
     store_regset (regcache, tid, -1, NT_PPC_DSCR,
 		  PPC_LINUX_SIZEOF_DSCRREGSET,
 		  &ppc32_linux_dscrregset);
+  if (tdep->ppc_tar_regnum != -1)
+    store_regset (regcache, tid, -1, NT_PPC_TAR,
+		  PPC_LINUX_SIZEOF_TARREGSET,
+		  &ppc32_linux_tarregset);
 }
 
 /* Fetch the AT_HWCAP entry from the aux vector.  */
@@ -2399,7 +2425,13 @@ ppc_linux_nat_target::read_description ()
   if ((hwcap2 & PPC_FEATURE2_DSCR)
       && check_regset (tid, NT_PPC_PPR, PPC_LINUX_SIZEOF_PPRREGSET)
       && check_regset (tid, NT_PPC_DSCR, PPC_LINUX_SIZEOF_DSCRREGSET))
-    features.ppr_dscr = true;
+    {
+      features.ppr_dscr = true;
+      if ((hwcap2 & PPC_FEATURE2_ARCH_2_07)
+	  && (hwcap2 & PPC_FEATURE2_TAR)
+	  && check_regset (tid, NT_PPC_TAR, PPC_LINUX_SIZEOF_TARREGSET))
+	features.isa207 = true;
+    }
 
   return ppc_linux_match_description (features);
 }