* gdb.texinfo (Continuing and Stepping): When talking about "step"

[deliverable/binutils-gdb.git] / gdb / dcache.c

diff --git a/gdb/dcache.c b/gdb/dcache.c
index 498c22e2a4f56607f5e4be4e3bee8b9a49a31715..aaa01d0fe2279e45a3e1540524e4021725e24bbd 100644 (file)
--- a/gdb/dcache.c
+++ b/gdb/dcache.c
@@ -21,15 +21,18 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 #include "defs.h"
 #include "dcache.h"
+#include "gdbcmd.h"
 
 extern int insque();
 extern int remque();
 
+int remote_dcache = 0;
+
 /* The data cache records all the data read from the remote machine
    since the last time it stopped.
 
-   Each cache block holds line_size bytes of data
-   starting at a multiple-of-line_size address.  */
+   Each cache block holds LINE_SIZE bytes of data
+   starting at a multiple-of-LINE_SIZE address.  */
 
 #define LINE_SIZE_MASK ((LINE_SIZE - 1))       /* eg 7*2+1= 111*/
 #define XFORM(x)  (((x) & LINE_SIZE_MASK) >> 2)
@@ -41,17 +44,21 @@ dcache_flush (dcache)
 {
   register struct dcache_block *db;
 
-  while ((db = dcache->dcache_valid.next) != &dcache->dcache_valid)
-    {
-      remque (db);
-      insque (db, &dcache->dcache_free);
-    }
+  if (remote_dcache > 0)
+    while ((db = dcache->dcache_valid.next) != &dcache->dcache_valid)
+      {
+       remque (db);
+       insque (db, &dcache->dcache_free);
+      }
+
+  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;
@@ -59,7 +66,8 @@ dcache_hit (dcache, addr)
 {
   register struct dcache_block *db;
 
-  if (addr & 3)
+  if (addr & 3
+      || remote_dcache == 0)
     abort ();
 
   /* Search all cache blocks for one that is at this address.  */
@@ -70,16 +78,19 @@ dcache_hit (dcache, addr)
        return db;
       db = db->next;
     }
+
   return NULL;
 }
 
 /*  Return the int data at address ADDR in dcache block DC.  */
+static
 int
 dcache_value (db, addr)
      struct dcache_block *db;
      unsigned int addr;
 {
-  if (addr & 3)
+  if (addr & 3
+      || remote_dcache == 0)
     abort ();
   return (db->data[XFORM (addr)]);
 }
@@ -88,14 +99,19 @@ dcache_value (db, addr)
    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 ninMemGet is interrupted
-   (which used to put garbage blocks in the valid list...).  */
+   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();
+
   if ((db = dcache->dcache_free.next) == &dcache->dcache_free)
     {
       /* If we can't get one from the free list, take last valid and put
@@ -110,8 +126,8 @@ dcache_alloc (dcache)
   return (db);
 }
 
-/* Return the contents of the word at address ADDR in the remote machine,
-   using the data cache.  */
+/* 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;
@@ -119,6 +135,14 @@ dcache_fetch (dcache, addr)
 {
   register struct dcache_block *db;
 
+  if (remote_dcache == 0)
+    {
+      int i;
+
+      (*dcache->read_memory) (addr, (unsigned char *) &i, 4);
+      return(i);
+    }
+
   db = dcache_hit (dcache, addr);
   if (db == 0)
     {
@@ -142,6 +166,12 @@ dcache_poke (dcache, addr, data)
 {
   register struct dcache_block *db;
 
+  if (remote_dcache == 0)
+    {
+      (*dcache->write_memory) (addr, (unsigned char *) &data, 4);
+      return;
+    }
+
   /* First make sure the word is IN the cache.  DB is its cache block.  */
   db = dcache_hit (dcache, addr);
   if (db == 0)
@@ -151,8 +181,8 @@ dcache_poke (dcache, addr, data)
       (*dcache->write_memory) (addr & ~LINE_SIZE_MASK, (unsigned char *) db->data, LINE_SIZE);
       immediate_quit--;
       db->addr = addr & ~LINE_SIZE_MASK;
-      remque (db);             /* Off the free list */
-      insque (db, &dcache->dcache_valid);      /* On the valid list */
+      remque (db); /* Off the free list */
+      insque (db, &dcache->dcache_valid); /* On the valid list */
     }
 
   /* Modify the word in the cache.  */
@@ -174,10 +204,11 @@ dcache_init (reading, writing)
   register struct dcache_block *db;
   DCACHE *dcache;
 
-  dcache = xmalloc(sizeof(*dcache));
+  dcache = (DCACHE *) xmalloc (sizeof (*dcache));
   dcache->read_memory = reading;
   dcache->write_memory = writing;
-  dcache->the_cache = xmalloc(sizeof(*dcache->the_cache) * DCACHE_SIZE);
+  dcache->the_cache = (struct dcache_block *)
+    xmalloc (sizeof (*dcache->the_cache) * DCACHE_SIZE);
 
   dcache->dcache_free.next = dcache->dcache_free.last = &dcache->dcache_free;
   dcache->dcache_valid.next = dcache->dcache_valid.last = &dcache->dcache_valid;
@@ -187,3 +218,19 @@ dcache_init (reading, writing)
   return(dcache);
 }
 
+void
+_initialitize_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 off.", 
+                 &setlist),
+     &showlist);
+}