[PATCH 07/17] [PowerPC] Add gdbserver support for PPR and DSCR

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

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

This patch extends support for the Program Priority Register and the
Data Stream Control Register to the powerpc linux gdbserver stub.

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

	* linux-ppc-tdesc-init.h (enum ppc_linux_tdesc)
	<PPC_TDESC_ISA205_PPR_DSCR_VSX>: New enum value.
	(init_registers_powerpc_isa205_ppr_dscr_vsx32l)
	(init_registers_powerpc_isa205_ppr_dscr_vsx64l): Declare.
	* linux-ppc-low.c: Include "elf/common.h" and <sys/uio.h>.
	(ppc_hwcap2): New global.
	(ppc_check_regset, ppc_fill_pprregset, ppc_store_pprregset)
	(ppc_fill_dscrregset, ppc_store_dscrregset): New functions.
	(ppc_regsets): Add entries for the DSCR and PPR regsets.
	(ppc_arch_setup): Get AT_HWCAP2. Set ppr_dscr in features struct
	when needed. Set sizes for the the DSCR and PPR regsets.
	(ppc_get_ipa_tdesc_idx): Return PPC_TDESC_ISA205_PPR_DSCR_VSX.
	(initialize_low_arch): Call
	init_registers_powerpc_isa205_ppr_dscr_vsx32l and
	init_registers_powerpc_isa205_ppr_dscr_vsx64l.
	* linux-ppc-ipa.c (get_ipa_tdesc): Handle
	PPC_TDESC_ISA205_PPR_DSCR_VSX.
	(initialize_low_tracepoint): Call
	init_registers_powerpc_isa205_ppr_dscr_vsx32l and
	init_registers_powerpc_isa205_ppr_dscr_vsx64l.
---
 gdb/gdbserver/linux-ppc-ipa.c        |  6 +++
 gdb/gdbserver/linux-ppc-low.c        | 81 ++++++++++++++++++++++++++++++++++++
 gdb/gdbserver/linux-ppc-tdesc-init.h |  7 ++++
 3 files changed, 94 insertions(+)

diff --git a/gdb/gdbserver/linux-ppc-ipa.c b/gdb/gdbserver/linux-ppc-ipa.c
index f6861f0d98..c8b4c3b2da 100644
--- a/gdb/gdbserver/linux-ppc-ipa.c
+++ b/gdb/gdbserver/linux-ppc-ipa.c
@@ -191,6 +191,8 @@ get_ipa_tdesc (int idx)
       return tdesc_powerpc_isa205_altivec64l;
     case PPC_TDESC_ISA205_VSX:
       return tdesc_powerpc_isa205_vsx64l;
+    case PPC_TDESC_ISA205_PPR_DSCR_VSX:
+      return tdesc_powerpc_isa205_ppr_dscr_vsx64l;
 #else
     case PPC_TDESC_BASE:
       return tdesc_powerpc_32l;
@@ -206,6 +208,8 @@ get_ipa_tdesc (int idx)
       return tdesc_powerpc_isa205_altivec32l;
     case PPC_TDESC_ISA205_VSX:
       return tdesc_powerpc_isa205_vsx32l;
+    case PPC_TDESC_ISA205_PPR_DSCR_VSX:
+      return tdesc_powerpc_isa205_ppr_dscr_vsx32l;
     case PPC_TDESC_E500:
       return tdesc_powerpc_e500l;
 #endif
@@ -234,6 +238,7 @@ initialize_low_tracepoint (void)
   init_registers_powerpc_isa205_64l ();
   init_registers_powerpc_isa205_altivec64l ();
   init_registers_powerpc_isa205_vsx64l ();
+  init_registers_powerpc_isa205_ppr_dscr_vsx64l ();
 #else
   init_registers_powerpc_32l ();
   init_registers_powerpc_altivec32l ();
@@ -242,6 +247,7 @@ initialize_low_tracepoint (void)
   init_registers_powerpc_isa205_32l ();
   init_registers_powerpc_isa205_altivec32l ();
   init_registers_powerpc_isa205_vsx32l ();
+  init_registers_powerpc_isa205_ppr_dscr_vsx32l ();
   init_registers_powerpc_e500l ();
 #endif
 }
diff --git a/gdb/gdbserver/linux-ppc-low.c b/gdb/gdbserver/linux-ppc-low.c
index 47428c1529..502ce674fc 100644
--- a/gdb/gdbserver/linux-ppc-low.c
+++ b/gdb/gdbserver/linux-ppc-low.c
@@ -20,6 +20,8 @@
 #include "server.h"
 #include "linux-low.h"
 
+#include "elf/common.h"
+#include <sys/uio.h>
 #include <elf.h>
 #include <asm/ptrace.h>
 
@@ -42,6 +44,7 @@
 #define PPC_BD(insn)	(PPC_SEXT (PPC_FIELD (insn, 16, 14), 14) << 2)
 
 static unsigned long ppc_hwcap;
+static unsigned long ppc_hwcap2;
 
 
 #define ppc_num_regs 73
@@ -117,6 +120,21 @@ static int ppc_regmap_e500[] =
 #endif
 
 static int
+ppc_check_regset (int tid, int regset_id, int regsetsize)
+{
+  void *buf = alloca (regsetsize);
+  struct iovec iov;
+
+  iov.iov_base = buf;
+  iov.iov_len = regsetsize;
+
+  if (ptrace (PTRACE_GETREGSET, tid, regset_id, &iov) >= 0
+      || errno == ENODATA)
+    return 1;
+  return 0;
+}
+
+static int
 ppc_cannot_store_register (int regno)
 {
   const struct target_desc *tdesc = current_process ()->tdesc;
@@ -460,6 +478,38 @@ static void ppc_fill_gregset (struct regcache *regcache, void *buf)
 }
 
 static void
+ppc_fill_pprregset (struct regcache *regcache, void *buf)
+{
+  char *ppr = (char *) buf;
+
+  collect_register_by_name (regcache, "ppr", ppr);
+}
+
+static void
+ppc_store_pprregset (struct regcache *regcache, const void *buf)
+{
+  const char *ppr = (const char *) buf;
+
+  supply_register_by_name (regcache, "ppr", ppr);
+}
+
+static void
+ppc_fill_dscrregset (struct regcache *regcache, void *buf)
+{
+  char *dscr = (char *) buf;
+
+  collect_register_by_name (regcache, "dscr", dscr);
+}
+
+static void
+ppc_store_dscrregset (struct regcache *regcache, const void *buf)
+{
+  const char *dscr = (const char *) buf;
+
+  supply_register_by_name (regcache, "dscr", dscr);
+}
+
+static void
 ppc_fill_vsxregset (struct regcache *regcache, void *buf)
 {
   int i, base;
@@ -572,6 +622,10 @@ 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_PPR, 0, EXTENDED_REGS,
+  ppc_fill_pprregset, ppc_store_pprregset },
+  { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_PPC_DSCR, 0, EXTENDED_REGS,
+  ppc_fill_dscrregset, ppc_store_dscrregset },
   { PTRACE_GETVSXREGS, PTRACE_SETVSXREGS, 0, 0, EXTENDED_REGS,
   ppc_fill_vsxregset, ppc_store_vsxregset },
   { PTRACE_GETVRREGS, PTRACE_SETVRREGS, 0, 0, EXTENDED_REGS,
@@ -629,6 +683,7 @@ ppc_arch_setup (void)
   /* The value of current_process ()->tdesc needs to be set for this
      call.  */
   ppc_get_auxv (AT_HWCAP, &ppc_hwcap);
+  ppc_get_auxv (AT_HWCAP2, &ppc_hwcap2);
 
   features.isa205 = ppc_linux_has_isa205 (ppc_hwcap);
 
@@ -638,6 +693,11 @@ ppc_arch_setup (void)
   if (ppc_hwcap & PPC_FEATURE_HAS_ALTIVEC)
     features.altivec = true;
 
+  if ((ppc_hwcap2 & PPC_FEATURE2_DSCR)
+      && ppc_check_regset (tid, NT_PPC_DSCR, PPC_LINUX_SIZEOF_DSCRREGSET)
+      && ppc_check_regset (tid, NT_PPC_PPR, PPC_LINUX_SIZEOF_PPRREGSET))
+    features.ppr_dscr = true;
+
   if (ppc_hwcap & PPC_FEATURE_CELL)
     features.cell = true;
 
@@ -682,6 +742,21 @@ ppc_arch_setup (void)
 	else
 	  regset->size = 0;
 	break;
+      case PTRACE_GETREGSET:
+	switch (regset->nt_type)
+	  {
+	  case NT_PPC_PPR:
+	    regset->size = (features.ppr_dscr ?
+			    PPC_LINUX_SIZEOF_PPRREGSET : 0);
+	    break;
+	  case NT_PPC_DSCR:
+	    regset->size = (features.ppr_dscr ?
+			    PPC_LINUX_SIZEOF_DSCRREGSET : 0);
+	    break;
+	  default:
+	    break;
+	  }
+	break;
       default:
 	break;
       }
@@ -3057,6 +3132,8 @@ ppc_get_ipa_tdesc_idx (void)
     return PPC_TDESC_ISA205_ALTIVEC;
   if (tdesc == tdesc_powerpc_isa205_vsx64l)
     return PPC_TDESC_ISA205_VSX;
+  if (tdesc == tdesc_powerpc_isa205_ppr_dscr_vsx64l)
+    return PPC_TDESC_ISA205_PPR_DSCR_VSX;
 #endif
 
   if (tdesc == tdesc_powerpc_32l)
@@ -3073,6 +3150,8 @@ ppc_get_ipa_tdesc_idx (void)
     return PPC_TDESC_ISA205_ALTIVEC;
   if (tdesc == tdesc_powerpc_isa205_vsx32l)
     return PPC_TDESC_ISA205_VSX;
+  if (tdesc == tdesc_powerpc_isa205_ppr_dscr_vsx32l)
+    return PPC_TDESC_ISA205_PPR_DSCR_VSX;
   if (tdesc == tdesc_powerpc_e500l)
     return PPC_TDESC_E500;
 
@@ -3131,6 +3210,7 @@ initialize_low_arch (void)
   init_registers_powerpc_isa205_32l ();
   init_registers_powerpc_isa205_altivec32l ();
   init_registers_powerpc_isa205_vsx32l ();
+  init_registers_powerpc_isa205_ppr_dscr_vsx32l ();
   init_registers_powerpc_e500l ();
 #if __powerpc64__
   init_registers_powerpc_64l ();
@@ -3140,6 +3220,7 @@ initialize_low_arch (void)
   init_registers_powerpc_isa205_64l ();
   init_registers_powerpc_isa205_altivec64l ();
   init_registers_powerpc_isa205_vsx64l ();
+  init_registers_powerpc_isa205_ppr_dscr_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 422e7bd9c4..c5c10c0670 100644
--- a/gdb/gdbserver/linux-ppc-tdesc-init.h
+++ b/gdb/gdbserver/linux-ppc-tdesc-init.h
@@ -29,6 +29,7 @@ enum ppc_linux_tdesc {
   PPC_TDESC_ISA205,
   PPC_TDESC_ISA205_ALTIVEC,
   PPC_TDESC_ISA205_VSX,
+  PPC_TDESC_ISA205_PPR_DSCR_VSX,
   PPC_TDESC_E500,
 };
 
@@ -55,6 +56,9 @@ void init_registers_powerpc_isa205_altivec32l (void);
 /* Defined in auto-generated file powerpc-isa205-vsx32l.c.  */
 void init_registers_powerpc_isa205_vsx32l (void);
 
+/* Defined in auto-generated file powerpc-isa205-ppr-dscr-vsx32l.c.  */
+void init_registers_powerpc_isa205_ppr_dscr_vsx32l (void);
+
 /* Defined in auto-generated file powerpc-e500l.c.  */
 void init_registers_powerpc_e500l (void);
 
@@ -83,4 +87,7 @@ void init_registers_powerpc_isa205_altivec64l (void);
 /* Defined in auto-generated file powerpc-isa205-vsx64l.c.  */
 void init_registers_powerpc_isa205_vsx64l (void);
 
+/* Defined in auto-generated file powerpc-isa205-ppr-dscr-vsx64l.c.  */
+void init_registers_powerpc_isa205_ppr_dscr_vsx64l (void);
+
 #endif
-- 
2.13.6