-/* Caching code. Typically used by remote back ends for
- caching remote memory.
-
- Copyright 1992, 1993, 1995 Free Software Foundation, Inc.
+/* Caching code.
+ Copyright 1992-1993, 1995, 1998-1999, 2000 Free Software Foundation, Inc.
This file is part of GDB.
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
+ 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"
+#include "target.h"
/*
The data cache could lead to incorrect results because it doesn't know
read the cache line in the first place.
- */
+ */
/* This value regulates the number of cache blocks stored.
line, and reduce memory requirements, but increase the risk
of a line not being in memory */
-#define DCACHE_SIZE 64
+#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_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 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 */
+#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 */
- unsigned int 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 */
+ {
+ 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;
+ /* whether anything in state is dirty - used to speed up the
+ dirty scan. */
+ int anydirty;
- int refs;
-};
+ int refs;
+ };
-struct dcache_struct
-{
- /* Function to actually read the target memory. */
- memxferfunc read_memory;
+struct dcache_struct
+ {
+ /* 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;
+ };
- /* Function to actually write the target memory */
- memxferfunc write_memory;
+static int dcache_poke_byte (DCACHE *dcache, CORE_ADDR addr, char *ptr);
- /* free list */
- struct dcache_block *free_head;
- struct dcache_block *free_tail;
+static int dcache_peek_byte (DCACHE *dcache, CORE_ADDR addr, char *ptr);
- /* in use list */
- struct dcache_block *valid_head;
- struct dcache_block *valid_tail;
+static struct dcache_block *dcache_hit (DCACHE *dcache, CORE_ADDR addr);
- /* The cache itself. */
- struct dcache_block *the_cache;
+static int dcache_write_line (DCACHE *dcache, struct dcache_block *db);
- /* 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_read_line (DCACHE *dcache, struct dcache_block *db);
-int remote_dcache = 1;
+static struct dcache_block *dcache_alloc (DCACHE *dcache, CORE_ADDR addr);
-DCACHE *last_cache; /* Used by info dcache */
+static int dcache_writeback (DCACHE *dcache);
+static void dcache_info (char *exp, int tty);
+
+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;
/* 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;
- unsigned int addr;
+
+static struct dcache_block *
+dcache_hit (DCACHE *dcache, CORE_ADDR addr)
{
register struct dcache_block *db;
while (db)
{
- if (MASK(addr) == db->addr)
+ if (MASK (addr) == db->addr)
{
db->refs++;
return 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++)
if (db->state[s] == ENTRY_DIRTY)
{
int len = 0;
- for (e = s ; e < LINE_SIZE; e++, len++)
+ 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)
{
- /* 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;
- break;
+ int t = do_xfer_memory (db->addr + s + done,
+ db->data + s + done,
+ len - done, 1);
+ if (t <= 0)
+ return 0;
+ done += t;
}
+ memset (db->state + s, ENTRY_OK, len);
+ s = e;
+ }
}
}
db->anydirty = 0;
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...). */
-static
-struct dcache_block *
-dcache_alloc (dcache)
- DCACHE *dcache;
+ and return its address. */
+
+static struct dcache_block *
+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. */
-
-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;
-}
-
-/* Using the data cache DCACHE return the contents of the word at
- address ADDR in the remote machine.
-
- Returns 0 on error. */
-
-int
-dcache_peek (dcache, addr, data)
- DCACHE *dcache;
- CORE_ADDR addr;
- int *data;
-{
- char *dp = (char *) data;
- int i;
- for (i = 0; i < sizeof (int); i++)
- {
- if (!dcache_peek_byte (dcache, addr, dp + i))
- return 0;
- }
- return 1;
-}
-
-
/* 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;
-{
- int res;
- dcache_peek (dcache, addr, &res);
- return res;
-}
-
+/* Using the data cache DCACHE return the contents of the byte at
+ address ADDR in the remote machine.
-/* Write the byte at PTR into ADDR in the data cache.
- Return zero on write error.
- */
+ Returns 0 on error. */
-int
-dcache_poke_byte (dcache, addr, ptr)
- DCACHE *dcache;
- CORE_ADDR addr;
- char *ptr;
+static int
+dcache_peek_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;
+ }
+
+ if (db->state[XFORM (addr)] == ENTRY_BAD)
+ {
+ if (!dcache_read_line(dcache, db))
+ return 0;
}
- db->data[XFORM (addr)] = *ptr;
- db->state[XFORM (addr)] = ENTRY_DIRTY;
- db->anydirty = 1;
+ *ptr = db->data[XFORM (addr)];
return 1;
}
-/* Write the word at ADDR both in the data cache and in the remote machine.
+
+/* Write the byte at PTR into ADDR in the data cache.
Return zero on write error.
*/
-int
-dcache_poke (dcache, addr, data)
- DCACHE *dcache;
- CORE_ADDR addr;
- int data;
+static int
+dcache_poke_byte (DCACHE *dcache, CORE_ADDR addr, char *ptr)
{
- char *dp = (char *) (&data);
- int i;
- for (i = 0; i < sizeof (int); i++)
+ register struct dcache_block *db = dcache_hit (dcache, addr);
+
+ if (!db)
{
- if (!dcache_poke_byte (dcache, addr, dp + i))
+ db = dcache_alloc (dcache, addr);
+ if (!db)
return 0;
}
- dcache_writeback (dcache);
+
+ db->data[XFORM (addr)] = *ptr;
+ db->state[XFORM (addr)] = ENTRY_DIRTY;
+ db->anydirty = 1;
return 1;
}
-
/* 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) ()
- = should_write ? dcache_poke_byte : dcache_peek_byte;
+ 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
+ else
{
- int (*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;
+static void
+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 %08xd, referenced %d times\n",
- p->addr, p->refs);
+ printf_filtered ("Cache state:\n");
- for (j = 0; j < LINE_SIZE; j++)
- printf_filtered ("%02x", p->data[j] & 0xFF);
- printf_filtered ("\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 (" %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);