arch/tile: add Tilera's <arch/sim.h> header as an open-source header

This change adds one of the Tilera standard <arch> headers to the set
of headers shipped with Linux.  The <arch/sim.h> header provides
methods for programmatically interacting with the Tilera simulator.

The current <arch/sim.h> provides inline assembly for the _sim_syscall
function, so the declaration and definition previously provided
manually in Linux are no longer needed.  We now use the standard
sim_validate_lines_evicted() method from <arch/sim.h> rather than
rolling our own direct call to sim_syscall().

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

2 files changed, 619 insertions, 7 deletions

diff --git a/arch/tile/include/arch/sim.h b/arch/tile/include/arch/sim.h
new file mode 100644
index 0000000..74b7c16
--- /dev/null
+++ b/arch/tile/include/arch/sim.h
@@ -0,0 +1,619 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   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, version 2.
+ *
+ *   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, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+/**
+ * @file
+ *
+ * Provides an API for controlling the simulator at runtime.
+ */
+
+/**
+ * @addtogroup arch_sim
+ * @{
+ *
+ * An API for controlling the simulator at runtime.
+ *
+ * The simulator's behavior can be modified while it is running.
+ * For example, human-readable trace output can be enabled and disabled
+ * around code of interest.
+ *
+ * There are two ways to modify simulator behavior:
+ * programmatically, by calling various sim_* functions, and
+ * interactively, by entering commands like "sim set functional true"
+ * at the tile-monitor prompt.  Typing "sim help" at that prompt provides
+ * a list of interactive commands.
+ *
+ * All interactive commands can also be executed programmatically by
+ * passing a string to the sim_command function.
+ */
+
+#ifndef __ARCH_SIM_H__
+#define __ARCH_SIM_H__
+
+#include <arch/sim_def.h>
+#include <arch/abi.h>
+
+#ifndef __ASSEMBLER__
+
+#include <arch/spr_def.h>
+
+
+/**
+ * Return true if the current program is running under a simulator,
+ * rather than on real hardware.  If running on hardware, other "sim_xxx()"
+ * calls have no useful effect.
+ */
+static inline int
+sim_is_simulator(void)
+{
+  return __insn_mfspr(SPR_SIM_CONTROL) != 0;
+}
+
+
+/**
+ * Checkpoint the simulator state to a checkpoint file.
+ *
+ * The checkpoint file name is either the default or the name specified
+ * on the command line with "--checkpoint-file".
+ */
+static __inline void
+sim_checkpoint(void)
+{
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_CHECKPOINT);
+}
+
+
+/**
+ * Report whether or not various kinds of simulator tracing are enabled.
+ *
+ * @return The bitwise OR of these values:
+ *
+ * SIM_TRACE_CYCLES (--trace-cycles),
+ * SIM_TRACE_ROUTER (--trace-router),
+ * SIM_TRACE_REGISTER_WRITES (--trace-register-writes),
+ * SIM_TRACE_DISASM (--trace-disasm),
+ * SIM_TRACE_STALL_INFO (--trace-stall-info)
+ * SIM_TRACE_MEMORY_CONTROLLER (--trace-memory-controller)
+ * SIM_TRACE_L2_CACHE (--trace-l2)
+ * SIM_TRACE_LINES (--trace-lines)
+ */
+static __inline unsigned int
+sim_get_tracing(void)
+{
+  return __insn_mfspr(SPR_SIM_CONTROL) & SIM_TRACE_FLAG_MASK;
+}
+
+
+/**
+ * Turn on or off different kinds of simulator tracing.
+ *
+ * @param mask Either one of these special values:
+ *
+ * SIM_TRACE_NONE (turns off tracing),
+ * SIM_TRACE_ALL (turns on all possible tracing).
+ *
+ * or the bitwise OR of these values:
+ *
+ * SIM_TRACE_CYCLES (--trace-cycles),
+ * SIM_TRACE_ROUTER (--trace-router),
+ * SIM_TRACE_REGISTER_WRITES (--trace-register-writes),
+ * SIM_TRACE_DISASM (--trace-disasm),
+ * SIM_TRACE_STALL_INFO (--trace-stall-info)
+ * SIM_TRACE_MEMORY_CONTROLLER (--trace-memory-controller)
+ * SIM_TRACE_L2_CACHE (--trace-l2)
+ * SIM_TRACE_LINES (--trace-lines)
+ */
+static __inline void
+sim_set_tracing(unsigned int mask)
+{
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_TRACE_SPR_ARG(mask));
+}
+
+
+/**
+ * Request dumping of different kinds of simulator state.
+ *
+ * @param mask Either this special value:
+ *
+ * SIM_DUMP_ALL (dump all known state)
+ *
+ * or the bitwise OR of these values:
+ *
+ * SIM_DUMP_REGS (the register file),
+ * SIM_DUMP_SPRS (the SPRs),
+ * SIM_DUMP_ITLB (the iTLB),
+ * SIM_DUMP_DTLB (the dTLB),
+ * SIM_DUMP_L1I (the L1 I-cache),
+ * SIM_DUMP_L1D (the L1 D-cache),
+ * SIM_DUMP_L2 (the L2 cache),
+ * SIM_DUMP_SNREGS (the switch register file),
+ * SIM_DUMP_SNITLB (the switch iTLB),
+ * SIM_DUMP_SNL1I (the switch L1 I-cache),
+ * SIM_DUMP_BACKTRACE (the current backtrace)
+ */
+static __inline void
+sim_dump(unsigned int mask)
+{
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_DUMP_SPR_ARG(mask));
+}
+
+
+/**
+ * Print a string to the simulator stdout.
+ *
+ * @param str The string to be written; a newline is automatically added.
+ */
+static __inline void
+sim_print_string(const char* str)
+{
+  int i;
+  for (i = 0; str[i] != 0; i++)
+  {
+    __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_PUTC |
+                 (str[i] << _SIM_CONTROL_OPERATOR_BITS));
+  }
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_PUTC |
+               (SIM_PUTC_FLUSH_STRING << _SIM_CONTROL_OPERATOR_BITS));
+}
+
+
+/**
+ * Execute a simulator command string.
+ *
+ * Type 'sim help' at the tile-monitor prompt to learn what commands
+ * are available.  Note the use of the tile-monitor "sim" command to
+ * pass commands to the simulator.
+ *
+ * The argument to sim_command() does not include the leading "sim"
+ * prefix used at the tile-monitor prompt; for example, you might call
+ * sim_command("trace disasm").
+ */
+static __inline void
+sim_command(const char* str)
+{
+  int c;
+  do
+  {
+    c = *str++;
+    __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_COMMAND |
+                 (c << _SIM_CONTROL_OPERATOR_BITS));
+  }
+  while (c);
+}
+
+
+
+#ifndef __DOXYGEN__
+
+/**
+ * The underlying implementation of "_sim_syscall()".
+ *
+ * We use extra "and" instructions to ensure that all the values
+ * we are passing to the simulator are actually valid in the registers
+ * (i.e. returned from memory) prior to the SIM_CONTROL spr.
+ */
+static __inline int _sim_syscall0(int val)
+{
+  long result;
+  __asm__ __volatile__ ("mtspr SIM_CONTROL, r0"
+                        : "=R00" (result) : "R00" (val));
+  return result;
+}
+
+static __inline int _sim_syscall1(int val, long arg1)
+{
+  long result;
+  __asm__ __volatile__ ("{ and zero, r1, r1; mtspr SIM_CONTROL, r0 }"
+                        : "=R00" (result) : "R00" (val), "R01" (arg1));
+  return result;
+}
+
+static __inline int _sim_syscall2(int val, long arg1, long arg2)
+{
+  long result;
+  __asm__ __volatile__ ("{ and zero, r1, r2; mtspr SIM_CONTROL, r0 }"
+                        : "=R00" (result)
+                        : "R00" (val), "R01" (arg1), "R02" (arg2));
+  return result;
+}
+
+/* Note that _sim_syscall3() and higher are technically at risk of
+   receiving an interrupt right before the mtspr bundle, in which case
+   the register values for arguments 3 and up may still be in flight
+   to the core from a stack frame reload. */
+
+static __inline int _sim_syscall3(int val, long arg1, long arg2, long arg3)
+{
+  long result;
+  __asm__ __volatile__ ("{ and zero, r3, r3 };"
+                        "{ and zero, r1, r2; mtspr SIM_CONTROL, r0 }"
+                        : "=R00" (result)
+                        : "R00" (val), "R01" (arg1), "R02" (arg2),
+                          "R03" (arg3));
+  return result;
+}
+
+static __inline int _sim_syscall4(int val, long arg1, long arg2, long arg3,
+                                  long arg4)
+{
+  long result;
+  __asm__ __volatile__ ("{ and zero, r3, r4 };"
+                        "{ and zero, r1, r2; mtspr SIM_CONTROL, r0 }"
+                        : "=R00" (result)
+                        : "R00" (val), "R01" (arg1), "R02" (arg2),
+                          "R03" (arg3), "R04" (arg4));
+  return result;
+}
+
+static __inline int _sim_syscall5(int val, long arg1, long arg2, long arg3,
+                                  long arg4, long arg5)
+{
+  long result;
+  __asm__ __volatile__ ("{ and zero, r3, r4; and zero, r5, r5 };"
+                        "{ and zero, r1, r2; mtspr SIM_CONTROL, r0 }"
+                        : "=R00" (result)
+                        : "R00" (val), "R01" (arg1), "R02" (arg2),
+                          "R03" (arg3), "R04" (arg4), "R05" (arg5));
+  return result;
+}
+
+
+/**
+ * Make a special syscall to the simulator itself, if running under
+ * simulation. This is used as the implementation of other functions
+ * and should not be used outside this file.
+ *
+ * @param syscall_num The simulator syscall number.
+ * @param nr The number of additional arguments provided.
+ *
+ * @return Varies by syscall.
+ */
+#define _sim_syscall(syscall_num, nr, args...) \
+  _sim_syscall##nr( \
+    ((syscall_num) << _SIM_CONTROL_OPERATOR_BITS) | SIM_CONTROL_SYSCALL, args)
+
+
+/* Values for the "access_mask" parameters below. */
+#define SIM_WATCHPOINT_READ    1
+#define SIM_WATCHPOINT_WRITE   2
+#define SIM_WATCHPOINT_EXECUTE 4
+
+
+static __inline int
+sim_add_watchpoint(unsigned int process_id,
+                   unsigned long address,
+                   unsigned long size,
+                   unsigned int access_mask,
+                   unsigned long user_data)
+{
+  return _sim_syscall(SIM_SYSCALL_ADD_WATCHPOINT, 5, process_id,
+                     address, size, access_mask, user_data);
+}
+
+
+static __inline int
+sim_remove_watchpoint(unsigned int process_id,
+                      unsigned long address,
+                      unsigned long size,
+                      unsigned int access_mask,
+                      unsigned long user_data)
+{
+  return _sim_syscall(SIM_SYSCALL_REMOVE_WATCHPOINT, 5, process_id,
+                     address, size, access_mask, user_data);
+}
+
+
+/**
+ * Return value from sim_query_watchpoint.
+ */
+struct SimQueryWatchpointStatus
+{
+  /**
+   * 0 if a watchpoint fired, 1 if no watchpoint fired, or -1 for
+   * error (meaning a bad process_id).
+   */
+  int syscall_status;
+
+  /**
+   * The address of the watchpoint that fired (this is the address
+   * passed to sim_add_watchpoint, not an address within that range
+   * that actually triggered the watchpoint).
+   */
+  unsigned long address;
+
+  /** The arbitrary user_data installed by sim_add_watchpoint. */
+  unsigned long user_data;
+};
+
+
+static __inline struct SimQueryWatchpointStatus
+sim_query_watchpoint(unsigned int process_id)
+{
+  struct SimQueryWatchpointStatus status;
+  long val = SIM_CONTROL_SYSCALL |
+    (SIM_SYSCALL_QUERY_WATCHPOINT << _SIM_CONTROL_OPERATOR_BITS);
+  __asm__ __volatile__ ("{ and zero, r1, r1; mtspr SIM_CONTROL, r0 }"
+                        : "=R00" (status.syscall_status),
+                          "=R01" (status.address),
+                          "=R02" (status.user_data)
+                        : "R00" (val), "R01" (process_id));
+  return status;
+}
+
+
+/* On the simulator, confirm lines have been evicted everywhere. */
+static __inline void
+sim_validate_lines_evicted(unsigned long long pa, unsigned long length)
+{
+#ifdef __LP64__
+  _sim_syscall(SIM_SYSCALL_VALIDATE_LINES_EVICTED, 2, pa, length);
+#else
+  _sim_syscall(SIM_SYSCALL_VALIDATE_LINES_EVICTED, 4,
+               0 /* dummy */, (long)(pa), (long)(pa >> 32), length);
+#endif
+}
+
+
+#endif /* !__DOXYGEN__ */
+
+
+
+
+/**
+ * Modify the shaping parameters of a shim.
+ *
+ * @param shim The shim to modify. One of:
+ *   SIM_CONTROL_SHAPING_GBE_0
+ *   SIM_CONTROL_SHAPING_GBE_1
+ *   SIM_CONTROL_SHAPING_GBE_2
+ *   SIM_CONTROL_SHAPING_GBE_3
+ *   SIM_CONTROL_SHAPING_XGBE_0
+ *   SIM_CONTROL_SHAPING_XGBE_1
+ *
+ * @param type The type of shaping. This should be the same type of
+ * shaping that is already in place on the shim. One of:
+ *   SIM_CONTROL_SHAPING_MULTIPLIER
+ *   SIM_CONTROL_SHAPING_PPS
+ *   SIM_CONTROL_SHAPING_BPS
+ *
+ * @param units The magnitude of the rate. One of:
+ *   SIM_CONTROL_SHAPING_UNITS_SINGLE
+ *   SIM_CONTROL_SHAPING_UNITS_KILO
+ *   SIM_CONTROL_SHAPING_UNITS_MEGA
+ *   SIM_CONTROL_SHAPING_UNITS_GIGA
+ *
+ * @param rate The rate to which to change it. This must fit in
+ * SIM_CONTROL_SHAPING_RATE_BITS bits or a warning is issued and
+ * the shaping is not changed.
+ *
+ * @return 0 if no problems were detected in the arguments to sim_set_shaping
+ * or 1 if problems were detected (for example, rate does not fit in 17 bits).
+ */
+static __inline int
+sim_set_shaping(unsigned shim,
+                unsigned type,
+                unsigned units,
+                unsigned rate)
+{
+  if ((rate & ~((1 << SIM_CONTROL_SHAPING_RATE_BITS) - 1)) != 0)
+    return 1;
+
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_SHAPING_SPR_ARG(shim, type, units, rate));
+  return 0;
+}
+
+#ifdef __tilegx__
+
+/** Enable a set of mPIPE links.  Pass a -1 link_mask to enable all links. */
+static __inline void
+sim_enable_mpipe_links(unsigned mpipe, unsigned long link_mask)
+{
+  __insn_mtspr(SPR_SIM_CONTROL,
+               (SIM_CONTROL_ENABLE_MPIPE_LINK_MAGIC_BYTE |
+                (mpipe << 8) | (1 << 16) | ((uint_reg_t)link_mask << 32)));
+}
+
+/** Disable a set of mPIPE links.  Pass a -1 link_mask to disable all links. */
+static __inline void
+sim_disable_mpipe_links(unsigned mpipe, unsigned long link_mask)
+{
+  __insn_mtspr(SPR_SIM_CONTROL,
+               (SIM_CONTROL_ENABLE_MPIPE_LINK_MAGIC_BYTE |
+                (mpipe << 8) | (0 << 16) | ((uint_reg_t)link_mask << 32)));
+}
+
+#endif /* __tilegx__ */
+
+
+/*
+ * An API for changing "functional" mode.
+ */
+
+#ifndef __DOXYGEN__
+
+#define sim_enable_functional() \
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_ENABLE_FUNCTIONAL)
+
+#define sim_disable_functional() \
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_DISABLE_FUNCTIONAL)
+
+#endif /* __DOXYGEN__ */
+
+
+/*
+ * Profiler support.
+ */
+
+/**
+ * Turn profiling on for the current task.
+ *
+ * Note that this has no effect if run in an environment without
+ * profiling support (thus, the proper flags to the simulator must
+ * be supplied).
+ */
+static __inline void
+sim_profiler_enable(void)
+{
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_PROFILER_ENABLE);
+}
+
+
+/** Turn profiling off for the current task. */
+static __inline void
+sim_profiler_disable(void)
+{
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_PROFILER_DISABLE);
+}
+
+
+/**
+ * Turn profiling on or off for the current task.
+ *
+ * @param enabled If true, turns on profiling. If false, turns it off.
+ *
+ * Note that this has no effect if run in an environment without
+ * profiling support (thus, the proper flags to the simulator must
+ * be supplied).
+ */
+static __inline void
+sim_profiler_set_enabled(int enabled)
+{
+  int val =
+    enabled ? SIM_CONTROL_PROFILER_ENABLE : SIM_CONTROL_PROFILER_DISABLE;
+  __insn_mtspr(SPR_SIM_CONTROL, val);
+}
+
+
+/**
+ * Return true if and only if profiling is currently enabled
+ * for the current task.
+ *
+ * This returns false even if sim_profiler_enable() was called
+ * if the current execution environment does not support profiling.
+ */
+static __inline int
+sim_profiler_is_enabled(void)
+{
+  return ((__insn_mfspr(SPR_SIM_CONTROL) & SIM_PROFILER_ENABLED_MASK) != 0);
+}
+
+
+/**
+ * Reset profiling counters to zero for the current task.
+ *
+ * Resetting can be done while profiling is enabled.  It does not affect
+ * the chip-wide profiling counters.
+ */
+static __inline void
+sim_profiler_clear(void)
+{
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_CONTROL_PROFILER_CLEAR);
+}
+
+
+/**
+ * Enable specified chip-level profiling counters.
+ *
+ * Does not affect the per-task profiling counters.
+ *
+ * @param mask Either this special value:
+ *
+ * SIM_CHIP_ALL (enables all chip-level components).
+ *
+ * or the bitwise OR of these values:
+ *
+ * SIM_CHIP_MEMCTL (enable all memory controllers)
+ * SIM_CHIP_XAUI (enable all XAUI controllers)
+ * SIM_CHIP_MPIPE (enable all MPIPE controllers)
+ */
+static __inline void
+sim_profiler_chip_enable(unsigned int mask)
+{
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_PROFILER_CHIP_ENABLE_SPR_ARG(mask));
+}
+
+
+/**
+ * Disable specified chip-level profiling counters.
+ *
+ * Does not affect the per-task profiling counters.
+ *
+ * @param mask Either this special value:
+ *
+ * SIM_CHIP_ALL (disables all chip-level components).
+ *
+ * or the bitwise OR of these values:
+ *
+ * SIM_CHIP_MEMCTL (disable all memory controllers)
+ * SIM_CHIP_XAUI (disable all XAUI controllers)
+ * SIM_CHIP_MPIPE (disable all MPIPE controllers)
+ */
+static __inline void
+sim_profiler_chip_disable(unsigned int mask)
+{
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_PROFILER_CHIP_DISABLE_SPR_ARG(mask));
+}
+
+
+/**
+ * Reset specified chip-level profiling counters to zero.
+ *
+ * Does not affect the per-task profiling counters.
+ *
+ * @param mask Either this special value:
+ *
+ * SIM_CHIP_ALL (clears all chip-level components).
+ *
+ * or the bitwise OR of these values:
+ *
+ * SIM_CHIP_MEMCTL (clear all memory controllers)
+ * SIM_CHIP_XAUI (clear all XAUI controllers)
+ * SIM_CHIP_MPIPE (clear all MPIPE controllers)
+ */
+static __inline void
+sim_profiler_chip_clear(unsigned int mask)
+{
+  __insn_mtspr(SPR_SIM_CONTROL, SIM_PROFILER_CHIP_CLEAR_SPR_ARG(mask));
+}
+
+
+/*
+ * Event support.
+ */
+
+#ifndef __DOXYGEN__
+
+static __inline void
+sim_event_begin(unsigned int x)
+{
+#if defined(__tile__) && !defined(__NO_EVENT_SPR__)
+  __insn_mtspr(SPR_EVENT_BEGIN, x);
+#endif
+}
+
+static __inline void
+sim_event_end(unsigned int x)
+{
+#if defined(__tile__) && !defined(__NO_EVENT_SPR__)
+  __insn_mtspr(SPR_EVENT_END, x);
+#endif
+}
+
+#endif /* !__DOXYGEN__ */
+
+#endif /* !__ASSEMBLER__ */
+
+#endif /* !__ARCH_SIM_H__ */
+
+/** @} */
diff --git a/arch/tile/include/asm/system.h b/arch/tile/include/asm/system.h
index 96779c8..fb7ff95 100644
--- a/arch/tile/include/asm/system.h
+++ b/arch/tile/include/asm/system.h
@@ -217,13 +217,6 @@ int hardwall_deactivate(struct task_struct *task);
 } while (0)
 #endif
 
-/* Invoke the simulator "syscall" mechanism (see arch/tile/kernel/entry.S). */
-extern int _sim_syscall(int syscall_num, ...);
-#define sim_syscall(syscall_num, ...) \
-	_sim_syscall(SIM_CONTROL_SYSCALL + \
-		((syscall_num) << _SIM_CONTROL_OPERATOR_BITS), \
-		## __VA_ARGS__)
-
 /*
  * Kernel threads can check to see if they need to migrate their
  * stack whenever they return from a context switch; for user