[PATCH 14/17] [PowerPC] Add gdbserver support for HTM registers

[Pedro Franco de Carvalho <pedromfc@linux.ibm.com>]

This patch extends suport for the HTM registers to the powerpc linux
gdbserver stub.

The "fill" functions for checkpointed register sets are not
implemented, because ptrace can return ENODATA for these regsets
whenever the inferior is not in a transaction.

Since gdbserver writes all registers in one go before resuming the
inferior, this error would not be detected at the time the user tries
to write to one of the registers on the client side, and gdbserver
would print out warnings every time it resumes the inferior when it is
not in a transaction, so there is currently no straightforward way to
handle this case. This means the checkpointed registers in the
client-side regcache can become dirty when the user tries to write to
them, until the inferior is resumed and stopped again.

Another limitation for the checkpointed registers is that traceframes
don't record if registers are available or not, so if these registers
are collected when a tracepoint is hit and the inferior is not in a
transaction, the user will see zero values for all of them, instead of
the usual <unavailable>.

gdb/gdbserver/ChangeLog:
2018-07-05  Pedro Franco de Carvalho  <pedromfc@linux.ibm.com>

	* linux-ppc-tdesc-init.h (enum ppc_linux_tdesc)
	<PPC_TDESC_ISA207_HTM_VSX>: New enum value.
	(init_registers_powerpc_isa207_htm_vsx32l)
	(init_registers_powerpc_isa207_htm_vsx64l): Declare.
	* linux-ppc-low.c (ppc_fill_tm_sprregset, ppc_store_tm_sprregset)
	(ppc_store_tm_cgprregset, ppc_store_tm_cfprregset)
	(ppc_store_tm_cvrregset, ppc_store_tm_cvsxregset)
	(ppc_store_tm_cpprregset, ppc_store_tm_cdscrregset)
	(ppc_store_tm_ctarregset): New functions.
	(ppc_regsets): Add entries for HTM regsets.
	(ppc_arch_setup): Set htm in features struct when needed. Set
	sizes for the HTM regsets.
	(ppc_get_ipa_tdesc_idx): Return PPC_TDESC_ISA207_HTM_VSX.
	(initialize_low_arch): Call
	init_registers_powerpc_isa207_htm_vsx32l and
	init_registers_powerpc_isa207_htm_vsx64l.
	* linux-ppc-ipa.c (get_ipa_tdesc): Handle
	PPC_TDESC_ISA207_HTM_VSX.
	(initialize_low_tracepoint): Call
	init_registers_powerpc_isa207_htm_vsx32l and
	init_registers_powerpc_isa207_htm_vsx64l.
---
 gdb/gdbserver/linux-ppc-ipa.c        |   6 ++
 gdb/gdbserver/linux-ppc-low.c        | 187 ++++++++++++++++++++++++++++++++++-
 gdb/gdbserver/linux-ppc-tdesc-init.h |   7 ++
 3 files changed, 199 insertions(+), 1 deletion(-)

diff --git a/gdb/gdbserver/linux-ppc-ipa.c b/gdb/gdbserver/linux-ppc-ipa.c
index b543dceba5..348d455193 100644
--- a/gdb/gdbserver/linux-ppc-ipa.c
+++ b/gdb/gdbserver/linux-ppc-ipa.c
@@ -195,6 +195,8 @@ get_ipa_tdesc (int idx)
       return tdesc_powerpc_isa205_ppr_dscr_vsx64l;
     case PPC_TDESC_ISA207_VSX:
       return tdesc_powerpc_isa207_vsx64l;
+    case PPC_TDESC_ISA207_HTM_VSX:
+      return tdesc_powerpc_isa207_htm_vsx64l;
 #else
     case PPC_TDESC_BASE:
       return tdesc_powerpc_32l;
@@ -214,6 +216,8 @@ get_ipa_tdesc (int idx)
       return tdesc_powerpc_isa205_ppr_dscr_vsx32l;
     case PPC_TDESC_ISA207_VSX:
       return tdesc_powerpc_isa207_vsx32l;
+    case PPC_TDESC_ISA207_HTM_VSX:
+      return tdesc_powerpc_isa207_htm_vsx32l;
     case PPC_TDESC_E500:
       return tdesc_powerpc_e500l;
 #endif
@@ -244,6 +248,7 @@ initialize_low_tracepoint (void)
   init_registers_powerpc_isa205_vsx64l ();
   init_registers_powerpc_isa205_ppr_dscr_vsx64l ();
   init_registers_powerpc_isa207_vsx64l ();
+  init_registers_powerpc_isa207_htm_vsx64l ();
 #else
   init_registers_powerpc_32l ();
   init_registers_powerpc_altivec32l ();
@@ -254,6 +259,7 @@ initialize_low_tracepoint (void)
   init_registers_powerpc_isa205_vsx32l ();
   init_registers_powerpc_isa205_ppr_dscr_vsx32l ();
   init_registers_powerpc_isa207_vsx32l ();
+  init_registers_powerpc_isa207_htm_vsx32l ();
   init_registers_powerpc_e500l ();
 #endif
 }
diff --git a/gdb/gdbserver/linux-ppc-low.c b/gdb/gdbserver/linux-ppc-low.c
index 6c27368a36..2c830d638a 100644
--- a/gdb/gdbserver/linux-ppc-low.c
+++ b/gdb/gdbserver/linux-ppc-low.c
@@ -526,6 +526,127 @@ ppc_store_tarregset (struct regcache *regcache, const void *buf)
 }
 
 static void
+ppc_fill_tm_sprregset (struct regcache *regcache, void *buf)
+{
+  int i, base;
+  char *regset = (char *) buf;
+
+  base = find_regno (regcache->tdesc, "tfhar");
+  for (i = 0; i < 3; i++)
+    collect_register (regcache, base + i, &regset[i*8]);
+}
+
+static void
+ppc_store_tm_sprregset (struct regcache *regcache, const void *buf)
+{
+  int i, base;
+  char *regset = (char *) buf;
+
+  base = find_regno (regcache->tdesc, "tfhar");
+  for (i = 0; i < 3; i++)
+    supply_register (regcache, base + i, &regset[i*8]);
+}
+
+static void
+ppc_store_tm_cgprregset (struct regcache *regcache, const void *buf)
+{
+  int i, base, size, endian_offset;
+  char *regset = (char *) buf;
+
+  base = find_regno (regcache->tdesc, "cr0");
+  size = register_size (regcache->tdesc, base);
+
+  gdb_assert (size == 4 || size == 8);
+
+  for (i = 0; i < 32; i++)
+    supply_register (regcache, base + i, &regset[i*size]);
+
+  endian_offset = 0;
+
+  if ((size == 8) && (__BYTE_ORDER == __BIG_ENDIAN))
+    endian_offset = 4;
+
+  supply_register_by_name (regcache, "ccr",
+			   &regset[PT_CCR * size + endian_offset]);
+
+  supply_register_by_name (regcache, "cxer",
+			   &regset[PT_XER * size + endian_offset]);
+
+  supply_register_by_name (regcache, "clr", &regset[PT_LNK * size]);
+  supply_register_by_name (regcache, "cctr", &regset[PT_CTR * size]);
+}
+
+static void
+ppc_store_tm_cfprregset (struct regcache *regcache, const void *buf)
+{
+  int i, base;
+  char *regset = (char *) buf;
+
+  base = find_regno (regcache->tdesc, "cf0");
+
+  for (i = 0; i < 32; i++)
+    supply_register (regcache, base + i, &regset[i*8]);
+
+  supply_register_by_name (regcache, "cfpscr", &regset[32*8]);
+}
+
+static void
+ppc_store_tm_cvrregset (struct regcache *regcache, const void *buf)
+{
+  int i, base;
+  char *regset = (char *) buf;
+  int vscr_offset = 0;
+
+  base = find_regno (regcache->tdesc, "cvr0");
+
+  for (i = 0; i < 32; i++)
+    supply_register (regcache, base + i, &regset[i*16]);
+
+  if (__BYTE_ORDER == __BIG_ENDIAN)
+    vscr_offset = 12;
+
+  supply_register_by_name (regcache, "cvscr",
+			   &regset[32 * 16 + vscr_offset]);
+
+  supply_register_by_name (regcache, "cvrsave", &regset[33 * 16]);
+}
+
+static void
+ppc_store_tm_cvsxregset (struct regcache *regcache, const void *buf)
+{
+  int i, base;
+  const char *regset = (const char *) buf;
+
+  base = find_regno (regcache->tdesc, "cvs0h");
+  for (i = 0; i < 32; i++)
+    supply_register (regcache, base + i, &regset[i * 8]);
+}
+
+static void
+ppc_store_tm_cpprregset (struct regcache *regcache, const void *buf)
+{
+  const char *cppr = (const char *) buf;
+
+  supply_register_by_name (regcache, "cppr", cppr);
+}
+
+static void
+ppc_store_tm_cdscrregset (struct regcache *regcache, const void *buf)
+{
+  const char *cdscr = (const char *) buf;
+
+  supply_register_by_name (regcache, "cdscr", cdscr);
+}
+
+static void
+ppc_store_tm_ctarregset (struct regcache *regcache, const void *buf)
+{
+  const char *ctar = (const char *) buf;
+
+  supply_register_by_name (regcache, "ctar", ctar);
+}
+
+static void
 ppc_fill_vsxregset (struct regcache *regcache, void *buf)
 {
   int i, base;
@@ -638,6 +759,22 @@ static struct regset_info ppc_regsets[] = {
      fetch them every time, but still fall back to PTRACE_PEEKUSER for the
      general registers.  Some kernels support these, but not the newer
      PPC_PTRACE_GETREGS.  */
+  { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PPC_TM_CTAR, 0, EXTENDED_REGS,
+    NULL, ppc_store_tm_ctarregset },
+  { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PPC_TM_CDSCR, 0, EXTENDED_REGS,
+    NULL, ppc_store_tm_cdscrregset },
+  { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PPC_TM_CPPR, 0, EXTENDED_REGS,
+    NULL, ppc_store_tm_cpprregset },
+  { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PPC_TM_CVSX, 0, EXTENDED_REGS,
+    NULL, ppc_store_tm_cvsxregset },
+  { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PPC_TM_CVMX, 0, EXTENDED_REGS,
+    NULL, ppc_store_tm_cvrregset },
+  { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PPC_TM_CFPR, 0, EXTENDED_REGS,
+    NULL, ppc_store_tm_cfprregset },
+  { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PPC_TM_CGPR, 0, EXTENDED_REGS,
+    NULL, ppc_store_tm_cgprregset },
+  { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PPC_TM_SPR, 0, EXTENDED_REGS,
+    ppc_fill_tm_sprregset, ppc_store_tm_sprregset },
   { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PPC_TAR, 0, EXTENDED_REGS,
   ppc_fill_tarregset, ppc_store_tarregset },
   { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PPC_PPR, 0, EXTENDED_REGS,
@@ -720,7 +857,13 @@ ppc_arch_setup (void)
 	  && (ppc_hwcap2 & PPC_FEATURE2_TAR)
 	  && ppc_check_regset (tid, NT_PPC_TAR,
 			       PPC_LINUX_SIZEOF_TARREGSET))
-	features.isa207 = true;
+	{
+	  features.isa207 = true;
+	  if ((ppc_hwcap2 & PPC_FEATURE2_HTM)
+	      && ppc_check_regset (tid, NT_PPC_TM_SPR,
+				   PPC_LINUX_SIZEOF_TM_SPRREGSET))
+	    features.htm = true;
+	}
     }
 
   if (ppc_hwcap & PPC_FEATURE_CELL)
@@ -782,6 +925,42 @@ ppc_arch_setup (void)
 	    regset->size = (features.isa207 ?
 			    PPC_LINUX_SIZEOF_TARREGSET : 0);
 	    break;
+	  case NT_PPC_TM_SPR:
+	    regset->size = (features.htm ?
+			    PPC_LINUX_SIZEOF_TM_SPRREGSET : 0);
+	    break;
+	  case NT_PPC_TM_CGPR:
+	    if (features.wordsize == 4)
+	      regset->size = (features.htm ?
+			      PPC32_LINUX_SIZEOF_CGPRREGSET : 0);
+	    else
+	      regset->size = (features.htm ?
+			      PPC64_LINUX_SIZEOF_CGPRREGSET : 0);
+	    break;
+	  case NT_PPC_TM_CFPR:
+	    regset->size = (features.htm ?
+			    PPC_LINUX_SIZEOF_CFPRREGSET : 0);
+	    break;
+	  case NT_PPC_TM_CVMX:
+	    regset->size = (features.htm ?
+			    PPC_LINUX_SIZEOF_CVMXREGSET : 0);
+	    break;
+	  case NT_PPC_TM_CVSX:
+	    regset->size = (features.htm ?
+			    PPC_LINUX_SIZEOF_CVSXREGSET : 0);
+	    break;
+	  case NT_PPC_TM_CPPR:
+	    regset->size = (features.htm ?
+			    PPC_LINUX_SIZEOF_CPPRREGSET : 0);
+	    break;
+	  case NT_PPC_TM_CDSCR:
+	    regset->size = (features.htm ?
+			    PPC_LINUX_SIZEOF_CDSCRREGSET : 0);
+	    break;
+	  case NT_PPC_TM_CTAR:
+	    regset->size = (features.htm ?
+			    PPC_LINUX_SIZEOF_CTARREGSET : 0);
+	    break;
 	  default:
 	    break;
 	  }
@@ -3165,6 +3344,8 @@ ppc_get_ipa_tdesc_idx (void)
     return PPC_TDESC_ISA205_PPR_DSCR_VSX;
   if (tdesc == tdesc_powerpc_isa207_vsx64l)
     return PPC_TDESC_ISA207_VSX;
+  if (tdesc == tdesc_powerpc_isa207_htm_vsx64l)
+    return PPC_TDESC_ISA207_HTM_VSX;
 #endif
 
   if (tdesc == tdesc_powerpc_32l)
@@ -3185,6 +3366,8 @@ ppc_get_ipa_tdesc_idx (void)
     return PPC_TDESC_ISA205_PPR_DSCR_VSX;
   if (tdesc == tdesc_powerpc_isa207_vsx32l)
     return PPC_TDESC_ISA207_VSX;
+  if (tdesc == tdesc_powerpc_isa207_htm_vsx32l)
+    return PPC_TDESC_ISA207_HTM_VSX;
   if (tdesc == tdesc_powerpc_e500l)
     return PPC_TDESC_E500;
 
@@ -3245,6 +3428,7 @@ initialize_low_arch (void)
   init_registers_powerpc_isa205_vsx32l ();
   init_registers_powerpc_isa205_ppr_dscr_vsx32l ();
   init_registers_powerpc_isa207_vsx32l ();
+  init_registers_powerpc_isa207_htm_vsx32l ();
   init_registers_powerpc_e500l ();
 #if __powerpc64__
   init_registers_powerpc_64l ();
@@ -3256,6 +3440,7 @@ initialize_low_arch (void)
   init_registers_powerpc_isa205_vsx64l ();
   init_registers_powerpc_isa205_ppr_dscr_vsx64l ();
   init_registers_powerpc_isa207_vsx64l ();
+  init_registers_powerpc_isa207_htm_vsx64l ();
 #endif
 
   initialize_regsets_info (&ppc_regsets_info);
diff --git a/gdb/gdbserver/linux-ppc-tdesc-init.h b/gdb/gdbserver/linux-ppc-tdesc-init.h
index 29b8122886..d1dfdad571 100644
--- a/gdb/gdbserver/linux-ppc-tdesc-init.h
+++ b/gdb/gdbserver/linux-ppc-tdesc-init.h
@@ -31,6 +31,7 @@ enum ppc_linux_tdesc {
   PPC_TDESC_ISA205_VSX,
   PPC_TDESC_ISA205_PPR_DSCR_VSX,
   PPC_TDESC_ISA207_VSX,
+  PPC_TDESC_ISA207_HTM_VSX,
   PPC_TDESC_E500,
 };
 
@@ -63,6 +64,9 @@ void init_registers_powerpc_isa205_ppr_dscr_vsx32l (void);
 /* Defined in auto-generated file powerpc-isa207-vsx32l.c.  */
 void init_registers_powerpc_isa207_vsx32l (void);
 
+/* Defined in auto-generated file powerpc-isa207-htm-vsx32l.c.  */
+void init_registers_powerpc_isa207_htm_vsx32l (void);
+
 /* Defined in auto-generated file powerpc-e500l.c.  */
 void init_registers_powerpc_e500l (void);
 
@@ -97,4 +101,7 @@ void init_registers_powerpc_isa205_ppr_dscr_vsx64l (void);
 /* Defined in auto-generated file powerpc-isa207-vsx64l.c.  */
 void init_registers_powerpc_isa207_vsx64l (void);
 
+/* Defined in auto-generated file powerpc-isa207-htm-vsx64l.c.  */
+void init_registers_powerpc_isa207_htm_vsx64l (void);
+
 #endif
-- 
2.13.6