Initial creation of sourceware repository

1 files changed, 0 insertions, 558 deletions

diff --git a/gdb/dcache.c b/gdb/dcache.c
deleted file mode 100644
index a97a940..0000000
--- a/gdb/dcache.c
+++ /dev/null
@@ -1,558 +0,0 @@
-/* Caching code.  Typically used by remote back ends for
-   caching remote memory.
-
-   Copyright 1992, 1993, 1995, 1998 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 2 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, write to the Free Software
-   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
-
-#include "defs.h"
-#include "dcache.h"
-#include "gdbcmd.h"
-#include "gdb_string.h"
-#include "gdbcore.h"
-
-/* 
-   The data cache could lead to incorrect results because it doesn't know
-   about volatile variables, thus making it impossible to debug
-   functions which use memory mapped I/O devices.
-
-   set remotecache 0
-
-   In those cases.
-
-   In general the dcache speeds up performance, some speed improvement
-   comes from the actual caching mechanism, but the major gain is in
-   the reduction of the remote protocol overhead; instead of reading
-   or writing a large area of memory in 4 byte requests, the cache
-   bundles up the requests into 32 byte (actually LINE_SIZE) chunks.
-   Reducing the overhead to an eighth of what it was.  This is very
-   obvious when displaying a large amount of data,
-
-   eg, x/200x 0 
-
-   caching     |   no    yes 
-   ---------------------------- 
-   first time  |   4 sec  2 sec improvement due to chunking 
-   second time |   4 sec  0 sec improvement due to caching
-
-   The cache structure is unusual, we keep a number of cache blocks
-   (DCACHE_SIZE) and each one caches a LINE_SIZEed area of memory.
-   Within each line we remember the address of the line (always a
-   multiple of the LINE_SIZE) and a vector of bytes over the range.
-   There's another vector which contains the state of the bytes.
-
-   ENTRY_BAD means that the byte is just plain wrong, and has no
-   correspondence with anything else (as it would when the cache is
-   turned on, but nothing has been done to it.
-
-   ENTRY_DIRTY means that the byte has some data in it which should be
-   written out to the remote target one day, but contains correct
-   data.  ENTRY_OK means that the data is the same in the cache as it
-   is in remote memory.
-
-
-   The ENTRY_DIRTY state is necessary because GDB likes to write large
-   lumps of memory in small bits.  If the caching mechanism didn't
-   maintain the DIRTY information, then something like a two byte
-   write would mean that the entire cache line would have to be read,
-   the two bytes modified and then written out again.  The alternative
-   would be to not read in the cache line in the first place, and just
-   write the two bytes directly into target memory.  The trouble with
-   that is that it really nails performance, because of the remote
-   protocol overhead.  This way, all those little writes are bundled
-   up into an entire cache line write in one go, without having to
-   read the cache line in the first place.
-
-
-  */
-
-
-/* This value regulates the number of cache blocks stored.
-   Smaller values reduce the time spent searching for a cache
-   line, and reduce memory requirements, but increase the risk
-   of a line not being in memory */
-
-#define DCACHE_SIZE 64 
-
-/* This value regulates the size of a cache line.  Smaller values
-   reduce the time taken to read a single byte, but reduce overall
-   throughput.  */
-
-#define LINE_SIZE_POWER (5) 
-#define LINE_SIZE (1 << LINE_SIZE_POWER)
-
-/* Each cache block holds LINE_SIZE bytes of data
-   starting at a multiple-of-LINE_SIZE address.  */
-
-#define LINE_SIZE_MASK  ((LINE_SIZE - 1))	
-#define XFORM(x) 	((x) & LINE_SIZE_MASK)
-#define MASK(x)         ((x) & ~LINE_SIZE_MASK)
-
-
-#define ENTRY_BAD   0  /* data at this byte is wrong */
-#define ENTRY_DIRTY 1  /* data at this byte needs to be written back */
-#define ENTRY_OK    2  /* data at this byte is same as in memory */
-
-
-struct dcache_block
-{
-  struct dcache_block *p;	/* next in list */
-  CORE_ADDR addr;		/* Address for which data is recorded.  */
-  char data[LINE_SIZE];		/* bytes at given address */
-  unsigned char state[LINE_SIZE]; /* what state the data is in */
-
-  /* whether anything in state is dirty - used to speed up the 
-     dirty scan. */
-  int anydirty;			
-
-  int refs;
-};
-
-
-struct dcache_struct 
-{
-  /* Function to actually read the target memory. */
-  memxferfunc read_memory;
-
-  /* Function to actually write the target memory */
-  memxferfunc write_memory;
-
-  /* free list */
-  struct dcache_block *free_head;
-  struct dcache_block *free_tail;
-
-  /* in use list */
-  struct dcache_block *valid_head;
-  struct dcache_block *valid_tail;
-
-  /* The cache itself. */
-  struct dcache_block *the_cache;
-
-  /* potentially, if the cache was enabled, and then turned off, and
-     then turned on again, the stuff in it could be stale, so this is
-     used to mark it */
-  int cache_has_stuff;
-} ;
-
-static int dcache_poke_byte PARAMS ((DCACHE *dcache, CORE_ADDR addr, 
-                                     char *ptr));
-
-static int dcache_peek_byte PARAMS ((DCACHE *dcache, CORE_ADDR addr, 
-                                     char *ptr));
-
-static struct dcache_block *dcache_hit PARAMS ((DCACHE *dcache, 
-                                                CORE_ADDR addr));
-
-static int dcache_write_line PARAMS ((DCACHE *dcache,struct dcache_block *db));
-
-static struct dcache_block *dcache_alloc PARAMS ((DCACHE *dcache));
-
-static int dcache_writeback PARAMS ((DCACHE *dcache));
-
-static void dcache_info PARAMS ((char *exp, int tty));
-
-void _initialize_dcache PARAMS ((void));
-
-int remote_dcache = 0;
-
-DCACHE *last_cache; /* Used by info dcache */
-
-
-/* Free all the data cache blocks, thus discarding all cached data.  */
-
-void
-dcache_flush (dcache)
-     DCACHE *dcache;
-{
-  int i;
-  dcache->valid_head = 0;
-  dcache->valid_tail = 0;
-
-  dcache->free_head = 0;
-  dcache->free_tail = 0;
-
-  for (i = 0; i < DCACHE_SIZE; i++)
-    {
-      struct dcache_block *db = dcache->the_cache + i;
-
-      if (!dcache->free_head)
-	dcache->free_head = db;
-      else
-	dcache->free_tail->p = db;
-      dcache->free_tail = db;
-      db->p = 0;
-    }
-
-  dcache->cache_has_stuff = 0;
-
-  return;
-}
-
-/* If addr is present in the dcache, return the address of the block
-   containing it. */
-
-static struct dcache_block *
-dcache_hit (dcache, addr)
-     DCACHE *dcache;
-     CORE_ADDR addr;
-{
-  register struct dcache_block *db;
-
-  /* Search all cache blocks for one that is at this address.  */
-  db = dcache->valid_head;
-
-  while (db)
-    {
-      if (MASK(addr) == db->addr)
-	{
-	  db->refs++;
-	  return db;
-	}
-      db = db->p;
-    }
-
-  return NULL;
-}
-
-/* Make sure that anything in this line which needs to
-   be written is. */
-
-static int
-dcache_write_line (dcache, db)
-     DCACHE *dcache;
-     register struct dcache_block *db;
-{
-  int s;
-  int e;
-  s = 0;
-  if (db->anydirty)
-    {
-      for (s = 0; s < LINE_SIZE; s++)
-	{
-	  if (db->state[s] == ENTRY_DIRTY)
-	    {
-	      int len = 0;
-	      for (e = s ; e < LINE_SIZE; e++, len++)
-		if (db->state[e] != ENTRY_DIRTY)
-		  break;
-	      {
-		/* all bytes from s..s+len-1 need to
-		   be written out */
-		int done = 0;
-		while (done < len) {
-		  int t = dcache->write_memory (db->addr + s + done,
-						db->data + s + done,
-						len - done);
-		  if (t == 0)
-		    return 0;
-		  done += t;
-		}
-		memset (db->state + s, ENTRY_OK, len);
-		s = e;
-	      }
-	    }
-	}
-      db->anydirty = 0;
-    }
-  return 1;
-}
-
-
-/* Get a free cache block, put or keep it on the valid list,
-   and return its address.  The caller should store into the block
-   the address and data that it describes, then remque it from the
-   free list and insert it into the valid list.  This procedure
-   prevents errors from creeping in if a memory retrieval is
-   interrupted (which used to put garbage blocks in the valid
-   list...).  */
-
-static struct dcache_block *
-dcache_alloc (dcache)
-     DCACHE *dcache;
-{
-  register struct dcache_block *db;
-
-  if (remote_dcache == 0)
-    abort ();
-
-  /* Take something from the free list */
-  db = dcache->free_head;
-  if (db)
-    {
-      dcache->free_head = db->p;
-    }
-  else
-    {
-      /* Nothing left on free list, so grab one from the valid list */
-      db = dcache->valid_head;
-      dcache->valid_head = db->p;
-
-      dcache_write_line (dcache, db);
-    }
-
-  /* append this line to end of valid list */
-  if (!dcache->valid_head)
-    dcache->valid_head = db;
-  else
-    dcache->valid_tail->p = db;
-  dcache->valid_tail = db;
-  db->p = 0;
-
-  return db;
-}
-
-/* Using the data cache DCACHE return the contents of the byte at
-   address ADDR in the remote machine.  
-
-   Returns 0 on error. */
-
-static int
-dcache_peek_byte (dcache, addr, ptr)
-     DCACHE *dcache;
-     CORE_ADDR addr;
-     char *ptr;
-{
-  register struct dcache_block *db = dcache_hit (dcache, addr);
-  int ok=1;
-  int done = 0;
-  if (db == 0
-      || db->state[XFORM (addr)] == ENTRY_BAD)
-    {
-      if (db)
-	{
-	  dcache_write_line (dcache, db);
-	}
-    else
-      db = dcache_alloc (dcache);
-      immediate_quit++;
-      db->addr = MASK (addr);
-      while (done < LINE_SIZE) 
-	{
-	  int try =
-	    (*dcache->read_memory)
-	      (db->addr + done,
-	       db->data + done,
-	       LINE_SIZE - done);
-	  if (try == 0)
-	    return 0;
-	  done += try;
-	}
-      immediate_quit--;
-     
-      memset (db->state, ENTRY_OK, sizeof (db->data));
-      db->anydirty = 0;
-    }
-  *ptr = db->data[XFORM (addr)];
-  return ok;
-}
-
-/* Writeback any dirty lines to the remote. */
-static int
-dcache_writeback (dcache)
-     DCACHE *dcache;
-{
-  struct dcache_block *db;
-
-  db = dcache->valid_head;
-
-  while (db)
-    {
-      if (!dcache_write_line (dcache, db))
-	return 0;
-      db = db->p;
-    }
-  return 1;
-}
-
-
-/* Using the data cache DCACHE return the contents of the word at
-   address ADDR in the remote machine.  */
-int
-dcache_fetch (dcache, addr)
-     DCACHE *dcache;
-     CORE_ADDR addr;
-{
-  int res;
-
-  if (dcache_xfer_memory (dcache, addr, (char *)&res, sizeof res, 0) != sizeof res)
-    memory_error (EIO, addr);
-
-  return res;
-}
-
-
-/* Write the byte at PTR into ADDR in the data cache.
-   Return zero on write error.
- */
-
-static int
-dcache_poke_byte (dcache, addr, ptr)
-     DCACHE *dcache;
-     CORE_ADDR addr;
-     char *ptr;
-{
-  register struct dcache_block *db = dcache_hit (dcache, addr);
-
-  if (!db)
-    {
-      db = dcache_alloc (dcache);
-      db->addr = MASK (addr);
-      memset (db->state, ENTRY_BAD, sizeof (db->data));
-    }
-
-  db->data[XFORM (addr)] = *ptr;
-  db->state[XFORM (addr)] = ENTRY_DIRTY;
-  db->anydirty = 1;
-  return 1;
-}
-
-/* Write the word at ADDR both in the data cache and in the remote machine.  
-   Return zero on write error.
- */
-
-int
-dcache_poke (dcache, addr, data)
-     DCACHE *dcache;
-     CORE_ADDR addr;
-     int data;
-{
-  if (dcache_xfer_memory (dcache, addr, (char *)&data, sizeof data, 1) != sizeof data)
-    return 0;
-
-  return dcache_writeback (dcache);
-}
-
-
-/* Initialize the data cache.  */
-DCACHE *
-dcache_init (reading, writing)
-     memxferfunc reading;
-     memxferfunc writing;
-{
-  int csize = sizeof (struct dcache_block) * DCACHE_SIZE;
-  DCACHE *dcache;
-
-  dcache = (DCACHE *) xmalloc (sizeof (*dcache));
-  dcache->read_memory = reading;
-  dcache->write_memory = writing;
-
-  dcache->the_cache = (struct dcache_block *) xmalloc (csize);
-  memset (dcache->the_cache, 0, csize);
-
-  dcache_flush (dcache);
-
-  last_cache = dcache;
-  return dcache;
-}
-
-/* Read or write LEN bytes from inferior memory at MEMADDR, transferring
-   to or from debugger address MYADDR.  Write to inferior if SHOULD_WRITE is
-   nonzero. 
-
-   Returns length of data written or read; 0 for error.  
-
-   This routine is indended to be called by remote_xfer_ functions. */
-
-int
-dcache_xfer_memory (dcache, memaddr, myaddr, len, should_write)
-     DCACHE *dcache;
-     CORE_ADDR memaddr;
-     char *myaddr;
-     int len;
-     int should_write;
-{
-  int i;
-
-  if (remote_dcache) 
-    {
-      int (*xfunc) PARAMS ((DCACHE *dcache, CORE_ADDR addr, char *ptr));
-      xfunc = should_write ? dcache_poke_byte : dcache_peek_byte;
-
-      for (i = 0; i < len; i++)
-	{
-	  if (!xfunc (dcache, memaddr + i, myaddr + i))
-	    return 0;
-	}
-      dcache->cache_has_stuff = 1;
-      dcache_writeback (dcache);
-    }
-  else 
-    {
-      memxferfunc xfunc;
-      xfunc = should_write ? dcache->write_memory : dcache->read_memory;
-
-      if (dcache->cache_has_stuff)
-	dcache_flush (dcache);
-
-      len = xfunc (memaddr, myaddr, len);
-    }
-  return len;
-}
-
-static void 
-dcache_info (exp, tty)
-     char *exp;
-     int tty;
-{
-  struct dcache_block *p;
-
-  if (!remote_dcache)
-    {
-      printf_filtered ("Dcache not enabled\n");
-      return;
-    }
-  printf_filtered ("Dcache enabled, line width %d, depth %d\n",
-		   LINE_SIZE, DCACHE_SIZE);
-
-  printf_filtered ("Cache state:\n");
-
-  for (p = last_cache->valid_head; p; p = p->p)
-    {
-      int j;
-      printf_filtered ("Line at %08xd, referenced %d times\n",
-		       p->addr, p->refs);
-
-      for (j = 0; j < LINE_SIZE; j++)
-	printf_filtered ("%02x", p->data[j] & 0xFF);
-      printf_filtered ("\n");
-
-      for (j = 0; j < LINE_SIZE; j++)
-	printf_filtered (" %2x", p->state[j]);
-      printf_filtered ("\n");
-    }
-}
-
-void
-_initialize_dcache ()
-{
-  add_show_from_set
-    (add_set_cmd ("remotecache", class_support, var_boolean,
-		  (char *) &remote_dcache,
-		  "\
-Set cache use for remote targets.\n\
-When on, use data caching for remote targets.  For many remote targets\n\
-this option can offer better throughput for reading target memory.\n\
-Unfortunately, gdb does not currently know anything about volatile\n\
-registers and thus data caching will produce incorrect results with\n\
-volatile registers are in use.  By default, this option is on.",
-		  &setlist),
-     &showlist);
-
-  add_info ("dcache", dcache_info,
-	    "Print information on the dcache performance.");
-
-}