[13/17,PowerPC] Add support for HTM registers

From: Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com>

  From: Edjunior Barbosa Machado <emachado@linux.vnet.ibm.com>

This patch adds support for Hardware Transactional Memory registers
for the powerpc linux native and core file targets.

These registers include both the HTM special-purpose registers (TFHAR,
TEXASR and TFIAR) as well as the set of registers that are
checkpointed (saved) when a transaction is initiated, which the
processor restores in the event of a transaction failure.

The set of checkpointed general-purpose registers is returned by the
linux kernel in the same format as the regular general-purpose
registers, defined in struct pt_regs. However, the architecture
specifies that only some of the registers present in pt_regs are
checkpointed (GPRs 0-31, CR, XER, LR and CTR). The kernel fills the
slots for other registers with other info (e.g., nip is filled with
the contents of TFHAR). GDB doesn't handle these other registers. This
means that core files generated by GDB will show values of zero for
these registers, while core files generated by the kernel will have
other values. Core files generated by the kernel have a note section
for checkpointed GPRs with the same size for both 32-bit and 64-bit
threads, and the values for the registers of a 32-bit thread are
squeezed in the first half, with no useful data in the second
half. GDB generates a smaller note section for 32-bit threads, but can
read both sizes.

Access to the checkpointed CR (condition register) can be
confusing. The architecture only specifies that CR fields 1 to 7 (the
24 least significant bits) are checkpointed, but the kernel provides
all 8 fields (32 bits). The value of field 0 is not masked by ptrace,
so it will sometimes show the result of some kernel operation,
probably treclaim., which sets this field.

The checkpointed registers are marked not to be saved and
restored. Inferior function calls during an active transaction don't
work well, and it's unclear what should be done in this case. TEXASR
and TFIAR can be altered asynchronously, during transaction failure
recording, so they are also not saved and restored. For consistency
neither is TFHAR.

Record and replay also doesn't work well when transactions are
involved. This patch doesn't address this, so the values of the HTM
SPRs will sometimes be innacurate when the record/relay target is
enabled. For instance, executing a "tbegin." alters TFHAR and TEXASR,
but these changes are not currently recorded.

Because the checkpointed registers are only available when a
transaction is active (or suspended), ptrace can return ENODATA when
gdb tries to read these registers and the inferior is not in a
transactional state. The registers are set to the unavailable state
when this happens. When gbd tries to write to one of these registers,
and it is unavailable, an error is raised. When gdb tries to store to
all registers in one go (when store_registers called with -1), the
state of these registers is checked. If they are all unavailable, no
write is attempted, so that writes to all the other registers are
unaffected. If all are available, the write is attempted. Otherwise an
internal_error is raised.

Like for the previous patches, configure.srv is updated here to avoid
breaking the build at this patch.

gdb/ChangeLog:
YYYY-MM-DD  Edjunior Barbosa Machado  <emachado@linux.vnet.ibm.com>
	    Pedro Franco de Carvalho  <pedromfc@linux.ibm.com>

	* arch/ppc-linux-tdesc.h (tdesc_powerpc_isa207_htm_vsx32l)
	(tdesc_powerpc_isa207_htm_vsx64l): Declare.
	* arch/ppc-linux-common.h (PPC_LINUX_SIZEOF_TM_SPRREGSET)
	(PPC32_LINUX_SIZEOF_CGPRREGSET, PPC64_LINUX_SIZEOF_CGPRREGSET)
	(PPC_LINUX_SIZEOF_CFPRREGSET, PPC_LINUX_SIZEOF_CVMXREGSET)
	(PPC_LINUX_SIZEOF_CVSXREGSET, PPC_LINUX_SIZEOF_CPPRREGSET)
	(PPC_LINUX_SIZEOF_CDSCRREGSET, PPC_LINUX_SIZEOF_CTARREGSET):
	Define.
	(struct ppc_linux_features) <htm>: New field.
	(ppc_linux_no_features): Add initializer for htm field.
	* arch/ppc-linux-common.c (ppc_linux_match_description): Return
	new tdescs.
	* nat/ppc-linux.h (PPC_FEATURE2_HTM, NT_PPC_TM_CGPR)
	(NT_PPC_TM_CFPR, NT_PPC_TM_CVMX, NT_PPC_TM_CVSX)
	(NT_PPC_TM_SPR, NT_PPC_TM_CTAR, NT_PPC_TM_CPPR, NT_PPC_TM_CDSCR):
	Define if not already defined.
	* features/Makefile (WHICH): Add rs6000/powerpc-isa207-htm-vsx32l
	and rs6000/powerpc-isa207-htm-vsx64l.
	(XMLTOC): Add rs6000/powerpc-isa207-htm-vsx32l.xml and
	rs6000/powerpc-isa207-htm-vsx64l.xml.
	* features/rs6000/power-htm.xml: New file.
	* features/rs6000/power64-htm.xml: New file.
	* features/rs6000/powerpc-isa207-htm-vsx32l.xml: New file.
	* features/rs6000/powerpc-isa207-htm-vsx64l.xml: New file.
	* features/rs6000/powerpc-isa207-htm-vsx32l.c: Generate.
	* features/rs6000/powerpc-isa207-htm-vsx64l.c: Generate.
	* regformats/rs6000/powerpc-isa207-htm-vsx32l.dat: Generate.
	* regformats/rs6000/powerpc-isa207-htm-vsx64l.dat: Generate.
	* ppc-linux-nat.c (fetch_register, fetch_ppc_registers): Call
	fetch_regset with HTM regsets.
	(ppc_linux_regset_available_p): New function.
	(store_register, store_ppc_registers): Call store_regset with HTM
	regsets.
	(ppc_linux_nat_target::read_description): Set htm field in the
	features struct if needed.
	* ppc-linux-tdep.c: Include
	features/rs6000/powerpc-isa207-htm-vsx32l.c and
	features/rs6000/powerpc-isa207-htm-vsx64l.c.
	(ppc_linux_collect_vrregset): Zero pad if regno is the
	checkpointed VSCR or the checkpointed VRSAVE.
	(ppc_linux_collect_and_clear_cgprregset): New function.
	(ppc32_regmap_tm_spr, ppc32_regmap_cgpr, ppc64_le_regmap_cgpr)
	(ppc64_be_regmap_cgpr, ppc32_regmap_cfpr, ppc32_le_regmap_cvmx)
	(ppc32_be_regmap_cvmx, ppc32_regmap_cvsx, ppc32_regmap_cppr)
	(ppc32_regmap_cdscr, ppc32_regmap_ctar): New globals.
	(ppc32_linux_tm_sprregset, ppc32_linux_cfprregset)
	(ppc32_le_linux_cvmxregset, ppc32_be_linux_cvmxregset)
	(ppc32_linux_cvsxregset, ppc32_linux_cpprregset)
	(ppc32_linux_cdscrregset, ppc32_linux_ctarregset): New globals.
	(ppc_linux_cgprregset, ppc_linux_cvmxregset): New functions.
	(ppc_linux_iterate_over_regset_sections): Call back with the htm
	regsets.
	(ppc_linux_core_read_description): Check if the tm spr section is
	present and set htm in the features struct.
	(_initialize_ppc_linux_tdep): Call
	initialize_tdesc_powerpc_isa207_htm_vsx32l and
	initialize_tdesc_powerpc_isa207_htm_vsx64l.
	* ppc-linux-tdep.h (ppc_linux_cgprregset)
	(ppc32_linux_tm_sprregset, ppc32_linux_cfprregset)
	(ppc32_linux_cvsxregset, ppc32_linux_cpprregset)
	(ppc32_linux_cdscrregset, ppc32_linux_ctarregset)
	(ppc_linux_cvmxregset): Declare.
	* ppc-tdep.h (struct gdbarch_tdep) <have_htm, ppc_cvsr0_regnum>:
	New fields.
	(enum) <PPC_TFHAR_REGNUM, PPC_TEXASR_REGNUM, PPC_TFIAR_REGNUM>:
	New enum fields.
	<PPC_CR0_REGNUM, PPC_CCR_REGNUM, PPC_CXER_REGNUM>: Likewise.
	<PPC_CLR_REGNUM, PPC_CCTR_REGNUM, PPC_CF0_REGNUM>: Likewise.
	<PPC_CFPSCR_REGNUM, PPC_CVR0_REGNUM, PPC_CVSCR_REGNUM>: Likewise.
	<PPC_CVRSAVE_REGNUM, PPC_CVS0H_REGNUM, PPC_CPPR_REGNUM>: Likewise.
	<PPC_CDSCR_REGNUM, PPC_CTAR_REGNUM>: Likewise.
	(PPC_IS_TMSPR_REGNUM, PPC_IS_CKPTGP_REGNUM, PPC_IS_CKPTFP_REGNUM)
	(PPC_IS_CKPTVMX_REGNUM, PPC_IS_CKPTVSX_REGNUM): Define.
	* rs6000-tdep.c (IS_CVSX_PSEUDOREG): Define.
	(rs6000_register_name): Hide the upper halves of checkpointed VSX
	registers. Return names for the full checkpointed VSX registers.
	(rs6000_pseudo_register_type): Include checkpointed VSX registers
	in the assert expression and return rs6000_builtin_type_vec128 for
	them.
	(rs6000_pseudo_register_reggroup_p): Include checkpointed VSX
	registers in the assert expression.
	(cvsx_pseudo_register_read, cvsx_pseudo_register_write): New
	functions.
	(rs6000_pseudo_register_read, rs6000_pseudo_register_write)
	(rs6000_ax_pseudo_register_collect): Handle checkpointed VSX
	registers.
	(rs6000_gdbarch_init): Look for and validate the htm
	feature. Include checkpointed VSX pseudo-registers.

gdb/gdbserver/ChangeLog:
YYYY-MM-DD  Pedro Franco de Carvalho  <pedromfc@linux.ibm.com>

	* configure.srv (ipa_ppc_linux_regobj): Add
	powerpc-isa207-htm-vsx32l-ipa.o and
	powerpc-isa207-htm-vsx64l-ipa.o.
	(powerpc*-*-linux*): Add powerpc-isa207-htm-vsx32l.o and
	powerpc-isa207-htm-vsx64l.o to srv_regobj, add
	rs6000/power-htm.xml, rs6000/power64-htm.xml,
	rs6000/powerpc-isa207-htm-vsx32l.xml, and
	rs6000/powerpc-isa207-htm-vsx64l.xml to srv_xmlfiles.
---
 gdb/arch/ppc-linux-common.c                        |   6 +-
 gdb/arch/ppc-linux-common.h                        |  11 +
 gdb/arch/ppc-linux-tdesc.h                         |   2 +
 gdb/features/Makefile                              |   4 +
 gdb/features/rs6000/power-htm.xml                  | 174 ++++++++++
 gdb/features/rs6000/power64-htm.xml                | 174 ++++++++++
 gdb/features/rs6000/powerpc-isa207-htm-vsx32l.c    | 370 +++++++++++++++++++++
 gdb/features/rs6000/powerpc-isa207-htm-vsx32l.xml  |  20 ++
 gdb/features/rs6000/powerpc-isa207-htm-vsx64l.c    | 370 +++++++++++++++++++++
 gdb/features/rs6000/powerpc-isa207-htm-vsx64l.xml  |  20 ++
 gdb/gdbserver/configure.srv                        |   8 +-
 gdb/nat/ppc-linux.h                                |  43 +++
 gdb/ppc-linux-nat.c                                | 304 ++++++++++++++++-
 gdb/ppc-linux-tdep.c                               | 292 +++++++++++++++-
 gdb/ppc-linux-tdep.h                               |  22 ++
 gdb/ppc-tdep.h                                     |  44 +++
 .../rs6000/powerpc-isa207-htm-vsx32l.dat           | 288 ++++++++++++++++
 .../rs6000/powerpc-isa207-htm-vsx64l.dat           | 288 ++++++++++++++++
 gdb/rs6000-tdep.c                                  | 239 ++++++++++++-
 19 files changed, 2661 insertions(+), 18 deletions(-)
 create mode 100644 gdb/features/rs6000/power-htm.xml
 create mode 100644 gdb/features/rs6000/power64-htm.xml
 create mode 100644 gdb/features/rs6000/powerpc-isa207-htm-vsx32l.c
 create mode 100644 gdb/features/rs6000/powerpc-isa207-htm-vsx32l.xml
 create mode 100644 gdb/features/rs6000/powerpc-isa207-htm-vsx64l.c
 create mode 100644 gdb/features/rs6000/powerpc-isa207-htm-vsx64l.xml
 create mode 100644 gdb/regformats/rs6000/powerpc-isa207-htm-vsx32l.dat
 create mode 100644 gdb/regformats/rs6000/powerpc-isa207-htm-vsx64l.dat

[13/17,PowerPC] Add support for HTM registers

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