gdbserver: Add powerpc fast tracepoint support.

gdb/gdbserver/ChangeLog:

2016-03-31  Wei-cheng Wang  <cole945@gmail.com>
	    Marcin Kościelnicki  <koriakin@0x04.net>

	PR/17221
	* Makefile.in: Add powerpc-*-ipa.o
	* configure.srv: Add ipa_obj for powerpc*-linux.
	* linux-ppc-ipa.c: New file.
	* linux-ppc-low.c: Added linux-ppc-tdesc.h, ax.h, tracepoint.h
	includes.
	(PPC_FIELD): New macro.
	(PPC_SEXT): New macro.
	(PPC_OP6): New macro.
	(PPC_BO): New macro.
	(PPC_LI): New macro.
	(PPC_BD): New macro.
	(init_registers_*): Move prototype to linux-ppc-tdesc.h.
	(tdesc_*): Move declaration to linux-ppc-tdesc.h.
	(ppc_get_hwcap): Rename to ppc_get_auxv and add type parameter.
	(ppc_get_thread_area): New function.
	(is_elfv2_inferior): New function.
	(gen_ds_form): New function.
	(GEN_STD): New macro.
	(GEN_STDU): New macro.
	(GEN_LD): New macro.
	(GEN_LDU): New macro.
	(gen_d_form): New function.
	(GEN_ADDI): New macro.
	(GEN_ADDIS): New macro.
	(GEN_LI): New macro.
	(GEN_LIS): New macro.
	(GEN_ORI): New macro.
	(GEN_ORIS): New macro.
	(GEN_LWZ): New macro.
	(GEN_STW): New macro.
	(GEN_STWU): New macro.
	(gen_xfx_form): New function.
	(GEN_MFSPR): New macro.
	(GEN_MTSPR): New macro.
	(GEN_MFCR): New macro.
	(GEN_MTCR): New macro.
	(GEN_SYNC): New macro.
	(GEN_LWSYNC): New macro.
	(gen_x_form): New function.
	(GEN_OR): New macro.
	(GEN_MR): New macro.
	(GEN_LWARX): New macro.
	(GEN_STWCX): New macro.
	(GEN_CMPW): New macro.
	(gen_md_form): New function.
	(GEN_RLDICL): New macro.
	(GEN_RLDICR): New macro.
	(gen_i_form): New function.
	(GEN_B): New macro.
	(GEN_BL): New macro.
	(gen_b_form): New function.
	(GEN_BNE): New macro.
	(GEN_LOAD): New macro.
	(GEN_STORE): New macro.
	(gen_limm): New function.
	(gen_atomic_xchg): New function.
	(gen_call): New function.
	(ppc_relocate_instruction): New function.
	(ppc_install_fast_tracepoint_jump_pad): New function.
	(ppc_get_min_fast_tracepoint_insn_len): New function.
	(ppc_get_ipa_tdesc_idx): New function.
	(the_low_target): Wire in the new functions.
	(initialize_low_arch) [!__powerpc64__]: Don'it initialize 64-bit
	tdescs.
	* linux-ppc-tdesc.h: New file.

1 files changed, 245 insertions, 0 deletions

diff --git a/gdb/gdbserver/linux-ppc-ipa.c b/gdb/gdbserver/linux-ppc-ipa.c
new file mode 100644
index 0000000..8489c6e
--- /dev/null
+++ b/gdb/gdbserver/linux-ppc-ipa.c
@@ -0,0 +1,245 @@
+/* GNU/Linux/PowerPC specific low level interface, for the in-process
+   agent library for GDB.
+
+   Copyright (C) 2016 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 "server.h"
+#include <sys/mman.h>
+#include "tracepoint.h"
+#include "linux-ppc-tdesc.h"
+#ifdef HAVE_GETAUXVAL
+#include <sys/auxv.h>
+#endif
+
+/* These macros define the position of registers in the buffer collected
+   by the fast tracepoint jump pad.  */
+#define FT_CR_R0	0
+#define FT_CR_CR	32
+#define FT_CR_XER	33
+#define FT_CR_LR	34
+#define FT_CR_CTR	35
+#define FT_CR_PC	36
+#define FT_CR_GPR(n)	(FT_CR_R0 + (n))
+
+static const int ppc_ft_collect_regmap[] = {
+  /* GPRs */
+  FT_CR_GPR (0), FT_CR_GPR (1), FT_CR_GPR (2),
+  FT_CR_GPR (3), FT_CR_GPR (4), FT_CR_GPR (5),
+  FT_CR_GPR (6), FT_CR_GPR (7), FT_CR_GPR (8),
+  FT_CR_GPR (9), FT_CR_GPR (10), FT_CR_GPR (11),
+  FT_CR_GPR (12), FT_CR_GPR (13), FT_CR_GPR (14),
+  FT_CR_GPR (15), FT_CR_GPR (16), FT_CR_GPR (17),
+  FT_CR_GPR (18), FT_CR_GPR (19), FT_CR_GPR (20),
+  FT_CR_GPR (21), FT_CR_GPR (22), FT_CR_GPR (23),
+  FT_CR_GPR (24), FT_CR_GPR (25), FT_CR_GPR (26),
+  FT_CR_GPR (27), FT_CR_GPR (28), FT_CR_GPR (29),
+  FT_CR_GPR (30), FT_CR_GPR (31),
+  /* FPRs - not collected.  */
+  -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,
+  -1, -1, -1, -1, -1, -1, -1, -1,
+  FT_CR_PC, /* PC */
+  -1, /* MSR */
+  FT_CR_CR, /* CR */
+  FT_CR_LR, /* LR */
+  FT_CR_CTR, /* CTR */
+  FT_CR_XER, /* XER */
+  -1, /* FPSCR */
+};
+
+#define PPC_NUM_FT_COLLECT_GREGS \
+  (sizeof (ppc_ft_collect_regmap) / sizeof(ppc_ft_collect_regmap[0]))
+
+/* Supply registers collected by the fast tracepoint jump pad.
+   BUF is the second argument we pass to gdb_collect in jump pad.  */
+
+void
+supply_fast_tracepoint_registers (struct regcache *regcache,
+				  const unsigned char *buf)
+{
+  int i;
+
+  for (i = 0; i < PPC_NUM_FT_COLLECT_GREGS; i++)
+    {
+      if (ppc_ft_collect_regmap[i] == -1)
+	continue;
+      supply_register (regcache, i,
+		       ((char *) buf)
+			+ ppc_ft_collect_regmap[i] * sizeof (long));
+    }
+}
+
+/* Return the value of register REGNUM.  RAW_REGS is collected buffer
+   by jump pad.  This function is called by emit_reg.  */
+
+ULONGEST
+get_raw_reg (const unsigned char *raw_regs, int regnum)
+{
+  if (regnum >= PPC_NUM_FT_COLLECT_GREGS)
+    return 0;
+  if (ppc_ft_collect_regmap[regnum] == -1)
+    return 0;
+
+  return *(unsigned long *) (raw_regs
+			     + ppc_ft_collect_regmap[regnum] * sizeof (long));
+}
+
+/* Allocate buffer for the jump pads.  The branch instruction has a reach
+   of +/- 32MiB, and the executable is loaded at 0x10000000 (256MiB).
+
+   64-bit: To maximize the area of executable that can use tracepoints,
+   try allocating at 0x10000000 - size initially, decreasing until we hit
+   a free area.
+
+   32-bit: ld.so loads dynamic libraries right below the executable, so
+   we cannot depend on that area (dynamic libraries can be quite large).
+   Instead, aim right after the executable - at sbrk(0).  This will
+   cause future brk to fail, and malloc will fallback to mmap.  */
+
+void *
+alloc_jump_pad_buffer (size_t size)
+{
+#ifdef __powerpc64__
+  uintptr_t addr;
+  uintptr_t exec_base = getauxval (AT_PHDR);
+  int pagesize;
+  void *res;
+
+  if (exec_base == 0)
+    exec_base = 0x10000000;
+
+  pagesize = sysconf (_SC_PAGE_SIZE);
+  if (pagesize == -1)
+    perror_with_name ("sysconf");
+
+  addr = exec_base - size;
+
+  /* size should already be page-aligned, but this can't hurt.  */
+  addr &= ~(pagesize - 1);
+
+  /* Search for a free area.  If we hit 0, we're out of luck.  */
+  for (; addr; addr -= pagesize)
+    {
+      /* No MAP_FIXED - we don't want to zap someone's mapping.  */
+      res = mmap ((void *) addr, size,
+		  PROT_READ | PROT_WRITE | PROT_EXEC,
+		  MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+      /* If we got what we wanted, return.  */
+      if ((uintptr_t) res == addr)
+	return res;
+
+      /* If we got a mapping, but at a wrong address, undo it.  */
+      if (res != MAP_FAILED)
+	munmap (res, size);
+    }
+
+  return NULL;
+#else
+  void *target = sbrk (0);
+  void *res = mmap (target, size, PROT_READ | PROT_WRITE | PROT_EXEC,
+		    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+  if (res == target)
+    return res;
+
+  if (res != MAP_FAILED)
+    munmap (res, size);
+
+  return NULL;
+#endif
+}
+
+/* Return target_desc to use for IPA, given the tdesc index passed by
+   gdbserver.  */
+
+const struct target_desc *
+get_ipa_tdesc (int idx)
+{
+  switch (idx)
+    {
+#ifdef __powerpc64__
+    case PPC_TDESC_BASE:
+      return tdesc_powerpc_64l;
+    case PPC_TDESC_ALTIVEC:
+      return tdesc_powerpc_altivec64l;
+    case PPC_TDESC_CELL:
+      return tdesc_powerpc_cell64l;
+    case PPC_TDESC_VSX:
+      return tdesc_powerpc_vsx64l;
+    case PPC_TDESC_ISA205:
+      return tdesc_powerpc_isa205_64l;
+    case PPC_TDESC_ISA205_ALTIVEC:
+      return tdesc_powerpc_isa205_altivec64l;
+    case PPC_TDESC_ISA205_VSX:
+      return tdesc_powerpc_isa205_vsx64l;
+#else
+    case PPC_TDESC_BASE:
+      return tdesc_powerpc_32l;
+    case PPC_TDESC_ALTIVEC:
+      return tdesc_powerpc_altivec32l;
+    case PPC_TDESC_CELL:
+      return tdesc_powerpc_cell32l;
+    case PPC_TDESC_VSX:
+      return tdesc_powerpc_vsx32l;
+    case PPC_TDESC_ISA205:
+      return tdesc_powerpc_isa205_32l;
+    case PPC_TDESC_ISA205_ALTIVEC:
+      return tdesc_powerpc_isa205_altivec32l;
+    case PPC_TDESC_ISA205_VSX:
+      return tdesc_powerpc_isa205_vsx32l;
+    case PPC_TDESC_E500:
+      return tdesc_powerpc_e500l;
+#endif
+    default:
+      internal_error (__FILE__, __LINE__,
+                     "unknown ipa tdesc index: %d", idx);
+#ifdef __powerpc64__
+      return tdesc_powerpc_64l;
+#else
+      return tdesc_powerpc_32l;
+#endif
+    }
+}
+
+
+/* Initialize ipa_tdesc and others.  */
+
+void
+initialize_low_tracepoint (void)
+{
+#ifdef __powerpc64__
+  init_registers_powerpc_64l ();
+  init_registers_powerpc_altivec64l ();
+  init_registers_powerpc_cell64l ();
+  init_registers_powerpc_vsx64l ();
+  init_registers_powerpc_isa205_64l ();
+  init_registers_powerpc_isa205_altivec64l ();
+  init_registers_powerpc_isa205_vsx64l ();
+#else
+  init_registers_powerpc_32l ();
+  init_registers_powerpc_altivec32l ();
+  init_registers_powerpc_cell32l ();
+  init_registers_powerpc_vsx32l ();
+  init_registers_powerpc_isa205_32l ();
+  init_registers_powerpc_isa205_altivec32l ();
+  init_registers_powerpc_isa205_vsx32l ();
+  init_registers_powerpc_e500l ();
+#endif
+}