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break dcache code out of remote.c

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This commit is contained in:
K. Richard Pixley 1993-09-01 00:43:09 +00:00
parent 46cf424778
commit d538b510a0
5 changed files with 183 additions and 219 deletions
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13
gdb/ChangeLog
View File

@ -1,5 +1,18 @@
Tue Aug 31 15:01:27 1993 K. Richard Pixley (rich@sendai.cygnus.com)
Break dcache code out of remote.c.
* dcache.h: white space changes only.
* dcache.c: add user settable variable to set whether data caching
is in use.
* remote.c: include dcache.h. removed data caching code which is
now in dcache.c. Compile in data caching again. (data caching
is currently off by default.)
(remote_read_bytes, remote_write_bytes): change second arg to
unsigned char.
(remote_dcache): new static variable.
* Makefile.in (REMOTE_O): add dcache.o.
* config/m88k/m88k.mt (TDEPFILES): removed dcache.o.
Break dcache code out of remote-bug.c into dcache.[hc].
* Makefile.in (dcache_h): new macro.
(HFILES): added $(dcache_h).

2
gdb/Makefile.in
View File

@ -189,7 +189,7 @@ SER_HARDWIRE=ser-unix.o
# The `remote' debugging target is supported for most architectures,
# but not all (e.g. 960)
REMOTE_O=remote.o
REMOTE_O = remote.o dcache.o
# Host and target-dependent makefile fragments come in here.
####

67
gdb/dcache.c
View File

@ -21,10 +21,13 @@ 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.
@ -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)]);
}
@ -91,12 +102,16 @@ dcache_value (db, addr)
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
@ -111,8 +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;
@ -120,6 +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)
{
@ -143,6 +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)
@ -152,8 +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. */
@ -188,3 +217,19 @@ 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);
}

16
gdb/dcache.h
View File

@ -22,6 +22,16 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#ifndef DCACHE_H
#define DCACHE_H
/* The data cache leads to incorrect results because it doesn't know about
volatile variables, thus making it impossible to debug functions which
use hardware registers. Therefore it is #if 0'd out. Effect on
performance is some, for backtraces of functions with a few
arguments each. For functions with many arguments, the stack
frames don't fit in the cache blocks, which makes the cache less
helpful. Disabling the cache is a big performance win for fetching
large structures, because the cache code fetched data in 16-byte
chunks. */
#define LINE_SIZE_POWER (4)
/* eg 1<<3 == 8 */
#define LINE_SIZE (1 << LINE_SIZE_POWER)
@ -57,8 +67,14 @@ typedef struct {
} DCACHE;
/* Using the data cache DCACHE return the contents of the word at
address ADDR in the remote machine. */
int dcache_fetch PARAMS((DCACHE *dcache, CORE_ADDR addr));
/* Flush DCACHE. */
void dcache_flush PARAMS((DCACHE *dcache));
/* Initialize DCACHE. */
DCACHE *dcache_init PARAMS((memxferfunc reading, memxferfunc writing));
/* Write the word at ADDR both in the data cache and in the remote machine. */

304
gdb/remote.c
View File

@ -56,6 +56,8 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
read mem mAA..AA,LLLL AA..AA is address, LLLL is length.
reply XX..XX XX..XX is mem contents
Can be fewer bytes than requested
if able to read only part of the data.
or ENN NN is errno
write mem MAA..AA,LLLL:XX..XX
@ -63,7 +65,9 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
LLLL is number of bytes,
XX..XX is data
reply OK for success
ENN for an error
ENN for an error (this includes the case
where only part of the data was
written).
cont cAA..AA AA..AA is address to resume
If AA..AA is omitted,
@ -87,7 +91,16 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
n... = register number
r... = register contents
kill req k
kill request k
toggle debug d toggle debug flag (see 386 & 68k stubs)
reset r reset -- see sparc stub.
reserved <other> On other requests, the stub should
ignore the request and send an empty
response ($#<checksum>). This way
we can extend the protocol and GDB
can tell whether the stub it is
talking to uses the old or the new.
*/
#include "defs.h"
@ -102,6 +115,8 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include "terminal.h"
#include "gdbcmd.h"
#include "dcache.h"
#if !defined(DONT_USE_REMOTE)
#ifdef USG
#include <sys/types.h>
@ -112,11 +127,11 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* Prototypes for local functions */
static void
remote_write_bytes PARAMS ((CORE_ADDR memaddr, char *myaddr, int len));
static int
remote_write_bytes PARAMS ((CORE_ADDR memaddr, unsigned char *myaddr, int len));
static void
remote_read_bytes PARAMS ((CORE_ADDR memaddr, char *myaddr, int len));
static int
remote_read_bytes PARAMS ((CORE_ADDR memaddr, unsigned char *myaddr, int len));
static void
remote_files_info PARAMS ((struct target_ops *ignore));
@ -132,7 +147,7 @@ static void
remote_fetch_registers PARAMS ((int regno));
static void
remote_resume PARAMS ((int step, int siggnal));
remote_resume PARAMS ((int pid, int step, int siggnal));
static int
remote_start_remote PARAMS ((char *dummy));
@ -178,7 +193,6 @@ remote_interrupt_twice PARAMS ((int signo));
extern struct target_ops remote_ops; /* Forward decl */
static int kiodebug = 0;
/* This was 5 seconds, which is a long time to sit and wait.
Unless this is going though some terminal server or multiplexer or
other form of hairy serial connection, I would think 2 seconds would
@ -237,6 +251,8 @@ remote_start_remote (dummy)
/* Open a connection to a remote debugger.
NAME is the filename used for communication. */
static DCACHE *remote_dcache;
static void
remote_open (name, from_tty)
char *name;
@ -251,9 +267,7 @@ device is attached to the remote system (e.g. /dev/ttya).");
unpush_target (&remote_ops);
#if 0
dcache_init ();
#endif
remote_dcache = dcache_init (remote_read_bytes, remote_write_bytes);
remote_desc = SERIAL_OPEN (name);
if (!remote_desc)
@ -339,8 +353,8 @@ tohex (nib)
/* Tell the remote machine to resume. */
static void
remote_resume (step, siggnal)
int step, siggnal;
remote_resume (pid, step, siggnal)
int pid, step, siggnal;
{
char buf[PBUFSIZ];
@ -358,9 +372,7 @@ remote_resume (step, siggnal)
target_terminal_inferior ();
}
#if 0
dcache_flush ();
#endif
dcache_flush (remote_dcache);
strcpy (buf, step ? "s": "c");
@ -377,7 +389,7 @@ remote_interrupt (signo)
/* If this doesn't work, try more severe steps. */
signal (signo, remote_interrupt_twice);
if (kiodebug)
if (remote_debug)
printf ("remote_interrupt called\n");
SERIAL_WRITE (remote_desc, "\003", 1); /* Send a ^C */
@ -551,7 +563,6 @@ remote_store_registers (regno)
remote_send (buf);
}
#if 0
/* Read a word from remote address ADDR and return it.
This goes through the data cache. */
@ -559,6 +570,7 @@ int
remote_fetch_word (addr)
CORE_ADDR addr;
{
#if 0
if (icache)
{
extern CORE_ADDR text_start, text_end;
@ -570,7 +582,8 @@ remote_fetch_word (addr)
return buffer;
}
}
return dcache_fetch (addr);
#endif
return dcache_fetch (remote_dcache, addr);
}
/* Write a word WORD into remote address ADDR.
@ -581,20 +594,22 @@ remote_store_word (addr, word)
CORE_ADDR addr;
int word;
{
dcache_poke (addr, word);
dcache_poke (remote_dcache, addr, word);
}
#endif /* 0 */
/* Write memory data directly to the remote machine.
This does not inform the data cache; the data cache uses this.
MEMADDR is the address in the remote memory space.
MYADDR is the address of the buffer in our space.
LEN is the number of bytes. */
LEN is the number of bytes.
static void
Returns number of bytes transferred, or 0 for error. */
static int
remote_write_bytes (memaddr, myaddr, len)
CORE_ADDR memaddr;
char *myaddr;
unsigned char *myaddr;
int len;
{
char buf[PBUFSIZ];
@ -617,19 +632,33 @@ remote_write_bytes (memaddr, myaddr, len)
}
*p = '\0';
remote_send (buf);
putpkt (buf);
getpkt (buf, 0);
if (buf[0] == 'E')
{
/* There is no correspondance between what the remote protocol uses
for errors and errno codes. We would like a cleaner way of
representing errors (big enough to include errno codes, bfd_error
codes, and others). But for now just return EIO. */
errno = EIO;
return 0;
}
return len;
}
/* Read memory data directly from the remote machine.
This does not use the data cache; the data cache uses this.
MEMADDR is the address in the remote memory space.
MYADDR is the address of the buffer in our space.
LEN is the number of bytes. */
LEN is the number of bytes.
static void
Returns number of bytes transferred, or 0 for error. */
static int
remote_read_bytes (memaddr, myaddr, len)
CORE_ADDR memaddr;
char *myaddr;
unsigned char *myaddr;
int len;
{
char buf[PBUFSIZ];
@ -640,7 +669,18 @@ remote_read_bytes (memaddr, myaddr, len)
abort ();
sprintf (buf, "m%x,%x", memaddr, len);
remote_send (buf);
putpkt (buf);
getpkt (buf, 0);
if (buf[0] == 'E')
{
/* There is no correspondance between what the remote protocol uses
for errors and errno codes. We would like a cleaner way of
representing errors (big enough to include errno codes, bfd_error
codes, and others). But for now just return EIO. */
errno = EIO;
return 0;
}
/* Reply describes memory byte by byte,
each byte encoded as two hex characters. */
@ -649,10 +689,13 @@ remote_read_bytes (memaddr, myaddr, len)
for (i = 0; i < len; i++)
{
if (p[0] == 0 || p[1] == 0)
error ("Remote reply is too short: %s", buf);
/* Reply is short. This means that we were able to read only part
of what we wanted to. */
break;
myaddr[i] = fromhex (p[0]) * 16 + fromhex (p[1]);
p += 2;
}
return i;
}
/* Read or write LEN bytes from inferior memory at MEMADDR, transferring
@ -668,8 +711,10 @@ remote_xfer_memory(memaddr, myaddr, len, should_write, target)
int should_write;
struct target_ops *target; /* ignored */
{
int origlen = len;
int xfersize;
int bytes_xferred;
int total_xferred = 0;
while (len > 0)
{
if (len > MAXBUFBYTES)
@ -678,14 +723,20 @@ remote_xfer_memory(memaddr, myaddr, len, should_write, target)
xfersize = len;
if (should_write)
remote_write_bytes(memaddr, myaddr, xfersize);
bytes_xferred = remote_write_bytes (memaddr, myaddr, xfersize);
else
remote_read_bytes (memaddr, myaddr, xfersize);
memaddr += xfersize;
myaddr += xfersize;
len -= xfersize;
bytes_xferred = remote_read_bytes (memaddr, myaddr, xfersize);
/* If we get an error, we are done xferring. */
if (bytes_xferred == 0)
break;
memaddr += bytes_xferred;
myaddr += bytes_xferred;
len -= bytes_xferred;
total_xferred += bytes_xferred;
}
return origlen; /* no error possible */
return total_xferred;
}
static void
@ -765,7 +816,7 @@ putpkt (buf)
while (1)
{
if (kiodebug)
if (remote_debug)
{
*p = '\0';
printf ("Sending packet: %s...", buf2); fflush(stdout);
@ -781,7 +832,7 @@ putpkt (buf)
switch (ch)
{
case '+':
if (kiodebug)
if (remote_debug)
printf("Ack\n");
return;
case SERIAL_TIMEOUT:
@ -791,7 +842,7 @@ putpkt (buf)
case SERIAL_EOF:
error ("putpkt: EOF while trying to read ACK");
default:
if (kiodebug)
if (remote_debug)
printf ("%02X %c ", ch&0xFF, ch);
continue;
}
@ -832,7 +883,7 @@ getpkt (buf, forever)
if (forever)
continue;
if (++retries >= MAX_RETRIES)
if (kiodebug) puts_filtered ("Timed out.\n");
if (remote_debug) puts_filtered ("Timed out.\n");
goto out;
}
@ -850,13 +901,13 @@ getpkt (buf, forever)
c = readchar ();
if (c == SERIAL_TIMEOUT)
{
if (kiodebug)
if (remote_debug)
puts_filtered ("Timeout in mid-packet, retrying\n");
goto whole; /* Start a new packet, count retries */
}
if (c == '$')
{
if (kiodebug)
if (remote_debug)
puts_filtered ("Saw new packet start in middle of old one\n");
goto whole; /* Start a new packet, count retries */
}
@ -901,163 +952,10 @@ getpkt (buf, forever)
SERIAL_WRITE (remote_desc, "+", 1);
if (kiodebug)
if (remote_debug)
fprintf (stderr,"Packet received: %s\n", buf);
}
/* The data cache leads to incorrect results because it doesn't know about
volatile variables, thus making it impossible to debug functions which
use hardware registers. Therefore it is #if 0'd out. Effect on
performance is some, for backtraces of functions with a few
arguments each. For functions with many arguments, the stack
frames don't fit in the cache blocks, which makes the cache less
helpful. Disabling the cache is a big performance win for fetching
large structures, because the cache code fetched data in 16-byte
chunks. */
#if 0
/* The data cache records all the data read from the remote machine
since the last time it stopped.
Each cache block holds 16 bytes of data
starting at a multiple-of-16 address. */
#define DCACHE_SIZE 64 /* Number of cache blocks */
struct dcache_block {
struct dcache_block *next, *last;
unsigned int addr; /* Address for which data is recorded. */
int data[4];
};
struct dcache_block dcache_free, dcache_valid;
/* Free all the data cache blocks, thus discarding all cached data. */
static void
dcache_flush ()
{
register struct dcache_block *db;
while ((db = dcache_valid.next) != &dcache_valid)
{
remque (db);
insque (db, &dcache_free);
}
}
/*
* If addr is present in the dcache, return the address of the block
* containing it.
*/
struct dcache_block *
dcache_hit (addr)
{
register struct dcache_block *db;
if (addr & 3)
abort ();
/* Search all cache blocks for one that is at this address. */
db = dcache_valid.next;
while (db != &dcache_valid)
{
if ((addr & 0xfffffff0) == db->addr)
return db;
db = db->next;
}
return NULL;
}
/* Return the int data at address ADDR in dcache block DC. */
int
dcache_value (db, addr)
struct dcache_block *db;
unsigned int addr;
{
if (addr & 3)
abort ();
return (db->data[(addr>>2)&3]);
}
/* Get a free cache block, put it on the valid list,
and return its address. The caller should store into the block
the address and data that it describes. */
struct dcache_block *
dcache_alloc ()
{
register struct dcache_block *db;
if ((db = dcache_free.next) == &dcache_free)
/* If we can't get one from the free list, take last valid */
db = dcache_valid.last;
remque (db);
insque (db, &dcache_valid);
return (db);
}
/* Return the contents of the word at address ADDR in the remote machine,
using the data cache. */
int
dcache_fetch (addr)
CORE_ADDR addr;
{
register struct dcache_block *db;
db = dcache_hit (addr);
if (db == 0)
{
db = dcache_alloc ();
remote_read_bytes (addr & ~0xf, db->data, 16);
db->addr = addr & ~0xf;
}
return (dcache_value (db, addr));
}
/* Write the word at ADDR both in the data cache and in the remote machine. */
dcache_poke (addr, data)
CORE_ADDR addr;
int data;
{
register struct dcache_block *db;
/* First make sure the word is IN the cache. DB is its cache block. */
db = dcache_hit (addr);
if (db == 0)
{
db = dcache_alloc ();
remote_read_bytes (addr & ~0xf, db->data, 16);
db->addr = addr & ~0xf;
}
/* Modify the word in the cache. */
db->data[(addr>>2)&3] = data;
/* Send the changed word. */
remote_write_bytes (addr, &data, 4);
}
/* Initialize the data cache. */
dcache_init ()
{
register i;
register struct dcache_block *db;
db = (struct dcache_block *) xmalloc (sizeof (struct dcache_block) *
DCACHE_SIZE);
dcache_free.next = dcache_free.last = &dcache_free;
dcache_valid.next = dcache_valid.last = &dcache_valid;
for (i=0;i<DCACHE_SIZE;i++,db++)
insque (db, &dcache_free);
}
#endif /* 0 */
static void
remote_kill ()
{
@ -1099,7 +997,7 @@ static unsigned char break_insn[] = BREAKPOINT;
by the caller to be long enough to save sizeof BREAKPOINT bytes (this
is accomplished via BREAKPOINT_MAX). */
int
static int
remote_insert_breakpoint (addr, contents_cache)
CORE_ADDR addr;
char *contents_cache;
@ -1114,7 +1012,7 @@ remote_insert_breakpoint (addr, contents_cache)
return val;
}
int
static int
remote_remove_breakpoint (addr, contents_cache)
CORE_ADDR addr;
char *contents_cache;
@ -1172,13 +1070,5 @@ void
_initialize_remote ()
{
add_target (&remote_ops);
add_show_from_set (
add_set_cmd ("remotedebug", no_class, var_boolean, (char *)&kiodebug,
"Set debugging of remote serial I/O.\n\
When enabled, each packet sent or received with the remote target\n\
is displayed.", &setlist),
&showlist);
}
#endif