-/* Caching code. Typically used by remote back ends for
- caching remote memory.
-
- Copyright 1992, 1993, 1995, 1998 Free Software Foundation, Inc.
+/* Caching code.
+ Copyright 1992-1993, 1995, 1998-1999, 2000 Free Software Foundation, Inc.
This file is part of GDB.
#include "gdbcmd.h"
#include "gdb_string.h"
#include "gdbcore.h"
+#include "target.h"
/*
The data cache could lead to incorrect results because it doesn't know
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;
int cache_has_stuff;
};
-static int dcache_poke_byte PARAMS ((DCACHE * dcache, CORE_ADDR addr,
- char *ptr));
+static int dcache_poke_byte (DCACHE *dcache, CORE_ADDR addr, char *ptr);
-static int dcache_peek_byte PARAMS ((DCACHE * dcache, CORE_ADDR addr,
- char *ptr));
+static int dcache_peek_byte (DCACHE *dcache, CORE_ADDR addr, char *ptr);
-static struct dcache_block *dcache_hit PARAMS ((DCACHE * dcache,
- CORE_ADDR addr));
+static struct dcache_block *dcache_hit (DCACHE *dcache, CORE_ADDR addr);
-static int dcache_write_line PARAMS ((DCACHE * dcache, struct dcache_block * db));
+static int dcache_write_line (DCACHE *dcache, struct dcache_block *db);
-static struct dcache_block *dcache_alloc PARAMS ((DCACHE * dcache));
+static int dcache_read_line (DCACHE *dcache, struct dcache_block *db);
-static int dcache_writeback PARAMS ((DCACHE * dcache));
+static struct dcache_block *dcache_alloc (DCACHE *dcache, CORE_ADDR addr);
-static void dcache_info PARAMS ((char *exp, int tty));
+static int dcache_writeback (DCACHE *dcache);
-void _initialize_dcache PARAMS ((void));
+static void dcache_info (char *exp, int tty);
-int remote_dcache = 0;
+void _initialize_dcache (void);
+
+static int dcache_enabled_p = 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;
+dcache_invalidate (DCACHE *dcache)
{
int i;
dcache->valid_head = 0;
containing it. */
static struct dcache_block *
-dcache_hit (dcache, addr)
- DCACHE *dcache;
- CORE_ADDR addr;
+dcache_hit (DCACHE *dcache, CORE_ADDR addr)
{
register struct dcache_block *db;
be written is. */
static int
-dcache_write_line (dcache, db)
- DCACHE *dcache;
- register struct dcache_block *db;
+dcache_write_line (DCACHE *dcache, register struct dcache_block *db)
{
int s;
int e;
- s = 0;
+
if (db->anydirty)
{
for (s = 0; s < LINE_SIZE; s++)
int done = 0;
while (done < len)
{
- int t = dcache->write_memory (db->addr + s + done,
- db->data + s + done,
- len - done);
- if (t == 0)
+ int t = do_xfer_memory (db->addr + s + done,
+ db->data + s + done,
+ len - done, 1);
+ if (t <= 0)
return 0;
done += t;
}
return 1;
}
+/* Read cache line */
+static int
+dcache_read_line (DCACHE *dcache, struct dcache_block *db)
+{
+ CORE_ADDR memaddr;
+ char *myaddr;
+ int len;
+ int res;
+
+ /* If there are any dirty bytes in the line, it must be written
+ before a new line can be read */
+ if (db->anydirty)
+ {
+ if (!dcache_write_line (dcache, db))
+ return 0;
+ }
+
+ len = LINE_SIZE;
+ memaddr = db->addr;
+ myaddr = db->data;
+
+ while (len > 0)
+ {
+ res = do_xfer_memory (memaddr, myaddr, len, 0);
+ if (res <= 0)
+ return 0;
+
+ memaddr += res;
+ myaddr += res;
+ len -= res;
+ }
+
+ memset (db->state, ENTRY_OK, sizeof (db->data));
+ 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...). */
+ and return its address. */
static struct dcache_block *
-dcache_alloc (dcache)
- DCACHE *dcache;
+dcache_alloc (DCACHE *dcache, CORE_ADDR addr)
{
register struct dcache_block *db;
- if (remote_dcache == 0)
+ if (dcache_enabled_p == 0)
abort ();
/* Take something from the free list */
{
/* 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);
+ if (!dcache_write_line (dcache, db))
+ return NULL;
+
+ dcache->valid_head = db->p;
}
+ db->addr = MASK(addr);
+ db->refs = 0;
+ db->anydirty = 0;
+ memset (db->state, ENTRY_BAD, sizeof (db->data));
+
/* append this line to end of valid list */
if (!dcache->valid_head)
dcache->valid_head = db;
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;
+dcache_writeback (DCACHE *dcache)
{
struct dcache_block *db;
}
-/* 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;
+/* 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 *dcache, CORE_ADDR addr, char *ptr)
{
- int res;
+ register struct dcache_block *db = dcache_hit (dcache, addr);
- if (dcache_xfer_memory (dcache, addr, (char *) &res, sizeof res, 0) != sizeof res)
- memory_error (EIO, addr);
+ if (!db)
+ {
+ db = dcache_alloc (dcache, addr);
+ if (!db)
+ return 0;
+ }
+
+ if (db->state[XFORM (addr)] == ENTRY_BAD)
+ {
+ if (!dcache_read_line(dcache, db))
+ return 0;
+ }
- return res;
+ *ptr = db->data[XFORM (addr)];
+ return 1;
}
*/
static int
-dcache_poke_byte (dcache, addr, ptr)
- DCACHE *dcache;
- CORE_ADDR addr;
- char *ptr;
+dcache_poke_byte (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 = dcache_alloc (dcache, addr);
+ if (!db)
+ return 0;
}
db->data[XFORM (addr)] = *ptr;
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;
+dcache_init (void)
{
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);
+ dcache_invalidate (dcache);
last_cache = dcache;
return dcache;
}
+/* Free a data cache */
+void
+dcache_free (DCACHE *dcache)
+{
+ if (last_cache == dcache)
+ last_cache = NULL;
+
+ free (dcache->the_cache);
+ free (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.
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;
+dcache_xfer_memory (DCACHE *dcache, CORE_ADDR memaddr, char *myaddr, int len,
+ int should_write)
{
int i;
- if (remote_dcache)
+ if (dcache_enabled_p)
{
- int (*xfunc) PARAMS ((DCACHE * dcache, CORE_ADDR addr, char *ptr));
+ int (*xfunc) (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;
}
+
+ if (should_write)
+ dcache_writeback (dcache);
+
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);
+ dcache_invalidate (dcache);
- len = xfunc (memaddr, myaddr, len);
+ len = do_xfer_memory(memaddr, myaddr, len, should_write);
}
return len;
}
static void
-dcache_info (exp, tty)
- char *exp;
- int tty;
+dcache_info (char *exp, int tty)
{
struct dcache_block *p;
- if (!remote_dcache)
+ if (!dcache_enabled_p)
{
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)
+ if (last_cache)
{
- int j;
- printf_filtered ("Line at %s, referenced %d times\n",
- paddr (p->addr), p->refs);
+ printf_filtered ("Cache state:\n");
+
+ for (p = last_cache->valid_head; p; p = p->p)
+ {
+ int j;
+ printf_filtered ("Line at %s, referenced %d times\n",
+ paddr (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 ("%02x", p->data[j] & 0xFF);
+ printf_filtered ("\n");
- for (j = 0; j < LINE_SIZE; j++)
- printf_filtered (" %2x", p->state[j]);
- printf_filtered ("\n");
+ for (j = 0; j < LINE_SIZE; j++)
+ printf_filtered ("%2x", p->state[j]);
+ printf_filtered ("\n");
+ }
}
}
+/* Turn dcache on or off. */
+void
+set_dcache_state (int what)
+{
+ dcache_enabled_p = !!what;
+}
+
void
-_initialize_dcache ()
+_initialize_dcache (void)
{
add_show_from_set
(add_set_cmd ("remotecache", class_support, var_boolean,
- (char *) &remote_dcache,
+ (char *) &dcache_enabled_p,
"\
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.",
+volatile registers are in use. By default, this option is off.",
&setlist),
&showlist);