/* Caching code for GDB, the GNU debugger.
- Copyright (C) 1992, 1993, 1995, 1996, 1998, 1999, 2000, 2001, 2003, 2007,
- 2008, 2009 Free Software Foundation, Inc.
+ Copyright (C) 1992-2017 Free Software Foundation, Inc.
This file is part of GDB.
#include "defs.h"
#include "dcache.h"
#include "gdbcmd.h"
-#include "gdb_string.h"
#include "gdbcore.h"
-#include "target.h"
+#include "target-dcache.h"
#include "inferior.h"
#include "splay-tree.h"
+/* Commands with a prefix of `{set,show} dcache'. */
+static struct cmd_list_element *dcache_set_list = NULL;
+static struct cmd_list_element *dcache_show_list = NULL;
+
/* 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 the nocache
/* The maximum number of lines stored. The total size of the cache is
equal to DCACHE_SIZE times LINE_SIZE. */
-#define DCACHE_SIZE 4096
+#define DCACHE_DEFAULT_SIZE 4096
+static unsigned dcache_size = DCACHE_DEFAULT_SIZE;
-/* The size of a cache line. Smaller values reduce the time taken to
+/* The default size of a cache line. Smaller values reduce the time taken to
read a single byte and make the cache more granular, but increase
overhead and reduce the effectiveness of the cache as a prefetcher. */
-#define LINE_SIZE_POWER 6
-#define LINE_SIZE (1 << LINE_SIZE_POWER)
+#define DCACHE_DEFAULT_LINE_SIZE 64
+static unsigned dcache_line_size = DCACHE_DEFAULT_LINE_SIZE;
/* 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 LINE_SIZE_MASK(dcache) ((dcache->line_size - 1))
+#define XFORM(dcache, x) ((x) & LINE_SIZE_MASK (dcache))
+#define MASK(dcache, x) ((x) & ~LINE_SIZE_MASK (dcache))
struct dcache_block
{
- /* for least-recently-allocated and free lists */
+ /* For least-recently-allocated and free lists. */
struct dcache_block *prev;
struct dcache_block *next;
CORE_ADDR addr; /* address of data */
- gdb_byte data[LINE_SIZE]; /* bytes at given address */
int refs; /* # hits */
+ gdb_byte data[1]; /* line_size bytes at given address */
};
struct dcache_struct
{
splay_tree tree;
- struct dcache_block *oldest; /* least-recently-allocated list */
+ struct dcache_block *oldest; /* least-recently-allocated list. */
/* The free list is maintained identically to OLDEST to simplify
the code: we only need one set of accessors. */
/* The number of in-use lines in the cache. */
int size;
+ CORE_ADDR line_size; /* current line_size. */
/* The ptid of last inferior to use cache or null_ptid. */
ptid_t ptid;
static struct dcache_block *dcache_hit (DCACHE *dcache, CORE_ADDR addr);
-static int dcache_write_line (DCACHE *dcache, struct dcache_block *db);
-
static int dcache_read_line (DCACHE *dcache, struct dcache_block *db);
static struct dcache_block *dcache_alloc (DCACHE *dcache, CORE_ADDR addr);
-static void dcache_info (char *exp, int tty);
-
-void _initialize_dcache (void);
-
static int dcache_enabled_p = 0; /* OBSOLETE */
static void
fprintf_filtered (file, _("Deprecated remotecache flag is %s.\n"), value);
}
-static DCACHE *last_cache; /* Used by info dcache */
-
/* Add BLOCK to circular block list BLIST, behind the block at *BLIST.
*BLIST is not updated (unless it was previously NULL of course).
This is for the least-recently-allocated list's sake:
while (*blist && db != *blist);
}
+/* BLOCK_FUNC routine for dcache_free. */
+
+static void
+free_block (struct dcache_block *block, void *param)
+{
+ xfree (block);
+}
+
+/* Free a data cache. */
+
+void
+dcache_free (DCACHE *dcache)
+{
+ splay_tree_delete (dcache->tree);
+ for_each_block (&dcache->oldest, free_block, NULL);
+ for_each_block (&dcache->freelist, free_block, NULL);
+ xfree (dcache);
+}
+
+
/* BLOCK_FUNC function for dcache_invalidate.
This doesn't remove the block from the oldest list on purpose.
dcache_invalidate will do it later. */
dcache->oldest = NULL;
dcache->size = 0;
dcache->ptid = null_ptid;
+
+ if (dcache->line_size != dcache_line_size)
+ {
+ /* We've been asked to use a different line size.
+ All of our freelist blocks are now the wrong size, so free them. */
+
+ for_each_block (&dcache->freelist, free_block, dcache);
+ dcache->freelist = NULL;
+ dcache->line_size = dcache_line_size;
+ }
}
/* Invalidate the line associated with ADDR. */
struct dcache_block *db;
splay_tree_node node = splay_tree_lookup (dcache->tree,
- (splay_tree_key) MASK (addr));
+ (splay_tree_key) MASK (dcache, addr));
if (!node)
return NULL;
int reg_len;
struct mem_region *region;
- len = LINE_SIZE;
+ len = dcache->line_size;
memaddr = db->addr;
myaddr = db->data;
len -= reg_len;
continue;
}
-
- res = target_read (¤t_target, TARGET_OBJECT_RAW_MEMORY,
- NULL, myaddr, memaddr, reg_len);
- if (res < reg_len)
+
+ res = target_read_raw_memory (memaddr, myaddr, reg_len);
+ if (res != 0)
return 0;
- memaddr += res;
- myaddr += res;
- len -= res;
+ memaddr += reg_len;
+ myaddr += reg_len;
+ len -= reg_len;
}
return 1;
{
struct dcache_block *db;
- if (dcache->size >= DCACHE_SIZE)
+ if (dcache->size >= dcache_size)
{
/* Evict the least recently allocated line. */
db = dcache->oldest;
if (db)
remove_block (&dcache->freelist, db);
else
- db = xmalloc (sizeof (struct dcache_block));
+ db = ((struct dcache_block *)
+ xmalloc (offsetof (struct dcache_block, data)
+ + dcache->line_size));
dcache->size++;
}
- db->addr = MASK (addr);
+ db->addr = MASK (dcache, addr);
db->refs = 0;
/* Put DB at the end of the list, it's the newest. */
return 0;
}
- *ptr = db->data[XFORM (addr)];
+ *ptr = db->data[XFORM (dcache, addr)];
return 1;
}
/* Write the byte at PTR into ADDR in the data cache.
- The caller is responsible for also promptly writing the data
- through to target memory.
-
- If addr is not in cache, this function does nothing; writing to
- an area of memory which wasn't present in the cache doesn't cause
- it to be loaded in.
+ The caller should have written the data through to target memory
+ already.
- Always return 1 (meaning success) to simplify dcache_xfer_memory. */
+ If ADDR is not in cache, this function does nothing; writing to an
+ area of memory which wasn't present in the cache doesn't cause it
+ to be loaded in. */
-static int
-dcache_poke_byte (DCACHE *dcache, CORE_ADDR addr, gdb_byte *ptr)
+static void
+dcache_poke_byte (DCACHE *dcache, CORE_ADDR addr, const gdb_byte *ptr)
{
struct dcache_block *db = dcache_hit (dcache, addr);
if (db)
- db->data[XFORM (addr)] = *ptr;
-
- return 1;
+ db->data[XFORM (dcache, addr)] = *ptr;
}
static int
DCACHE *
dcache_init (void)
{
- DCACHE *dcache;
- int i;
-
- dcache = (DCACHE *) xmalloc (sizeof (*dcache));
+ DCACHE *dcache = XNEW (DCACHE);
dcache->tree = splay_tree_new (dcache_splay_tree_compare,
NULL,
dcache->oldest = NULL;
dcache->freelist = NULL;
dcache->size = 0;
+ dcache->line_size = dcache_line_size;
dcache->ptid = null_ptid;
- last_cache = dcache;
return dcache;
}
-/* BLOCK_FUNC routine for dcache_free. */
-
-static void
-free_block (struct dcache_block *block, void *param)
-{
- free (block);
-}
-
-/* Free a data cache. */
-
-void
-dcache_free (DCACHE *dcache)
-{
- if (last_cache == dcache)
- last_cache = NULL;
-
- splay_tree_delete (dcache->tree);
- for_each_block (&dcache->oldest, free_block, NULL);
- for_each_block (&dcache->freelist, free_block, NULL);
- xfree (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.
- Return the number of bytes actually transfered, or -1 if the
- transfer is not supported or otherwise fails. Return of a non-negative
- value less than LEN indicates that no further transfer is possible.
- NOTE: This is different than the to_xfer_partial interface, in which
- positive values less than LEN mean further transfers may be possible. */
+/* Read LEN bytes from dcache memory at MEMADDR, transferring to
+ debugger address MYADDR. If the data is presently cached, this
+ fills the cache. Arguments/return are like the target_xfer_partial
+ interface. */
-int
-dcache_xfer_memory (struct target_ops *ops, DCACHE *dcache,
- CORE_ADDR memaddr, gdb_byte *myaddr,
- int len, int should_write)
+enum target_xfer_status
+dcache_read_memory_partial (struct target_ops *ops, DCACHE *dcache,
+ CORE_ADDR memaddr, gdb_byte *myaddr,
+ ULONGEST len, ULONGEST *xfered_len)
{
- int i;
- int res;
- int (*xfunc) (DCACHE *dcache, CORE_ADDR addr, gdb_byte *ptr);
- xfunc = should_write ? dcache_poke_byte : dcache_peek_byte;
+ ULONGEST i;
/* If this is a different inferior from what we've recorded,
flush the cache. */
dcache->ptid = inferior_ptid;
}
- /* Do write-through first, so that if it fails, we don't write to
- the cache at all. */
-
- if (should_write)
- {
- res = target_write (ops, TARGET_OBJECT_RAW_MEMORY,
- NULL, myaddr, memaddr, len);
- if (res <= 0)
- return res;
- /* Update LEN to what was actually written. */
- len = res;
- }
-
for (i = 0; i < len; i++)
{
- if (!xfunc (dcache, memaddr + i, myaddr + i))
+ if (!dcache_peek_byte (dcache, memaddr + i, myaddr + i))
{
/* That failed. Discard its cache line so we don't have a
partially read line. */
dcache_invalidate_line (dcache, memaddr + i);
- /* If we're writing, we still wrote LEN bytes. */
- if (should_write)
- return len;
- else
- return i;
+ break;
}
}
-
- return len;
+
+ if (i == 0)
+ {
+ /* Even though reading the whole line failed, we may be able to
+ read a piece starting where the caller wanted. */
+ return raw_memory_xfer_partial (ops, myaddr, NULL, memaddr, len,
+ xfered_len);
+ }
+ else
+ {
+ *xfered_len = i;
+ return TARGET_XFER_OK;
+ }
}
/* FIXME: There would be some benefit to making the cache write-back and
"logically" connected but not actually a single call to one of the
memory transfer functions. */
-/* Just update any cache lines which are already present. This is called
- by memory_xfer_partial in cases where the access would otherwise not go
- through the cache. */
+/* Just update any cache lines which are already present. This is
+ called by the target_xfer_partial machinery when writing raw
+ memory. */
void
-dcache_update (DCACHE *dcache, CORE_ADDR memaddr, gdb_byte *myaddr, int len)
+dcache_update (DCACHE *dcache, enum target_xfer_status status,
+ CORE_ADDR memaddr, const gdb_byte *myaddr,
+ ULONGEST len)
{
- int i;
+ ULONGEST i;
+
for (i = 0; i < len; i++)
- dcache_poke_byte (dcache, memaddr + i, myaddr + i);
+ if (status == TARGET_XFER_OK)
+ dcache_poke_byte (dcache, memaddr + i, myaddr + i);
+ else
+ {
+ /* Discard the whole cache line so we don't have a partially
+ valid line. */
+ dcache_invalidate_line (dcache, memaddr + i);
+ }
}
+/* Print DCACHE line INDEX. */
+
static void
-dcache_print_line (int index)
+dcache_print_line (DCACHE *dcache, int index)
{
splay_tree_node n;
struct dcache_block *db;
int i, j;
- if (!last_cache)
+ if (dcache == NULL)
{
printf_filtered (_("No data cache available.\n"));
return;
}
- n = splay_tree_min (last_cache->tree);
+ n = splay_tree_min (dcache->tree);
for (i = index; i > 0; --i)
{
if (!n)
break;
- n = splay_tree_successor (last_cache->tree, n->key);
+ n = splay_tree_successor (dcache->tree, n->key);
}
if (!n)
db = (struct dcache_block *) n->value;
printf_filtered (_("Line %d: address %s [%d hits]\n"),
- index, paddress (target_gdbarch, db->addr), db->refs);
+ index, paddress (target_gdbarch (), db->addr), db->refs);
- for (j = 0; j < LINE_SIZE; j++)
+ for (j = 0; j < dcache->line_size; j++)
{
printf_filtered ("%02x ", db->data[j]);
- /* Print a newline every 16 bytes (48 characters) */
- if ((j % 16 == 15) && (j != LINE_SIZE - 1))
+ /* Print a newline every 16 bytes (48 characters). */
+ if ((j % 16 == 15) && (j != dcache->line_size - 1))
printf_filtered ("\n");
}
printf_filtered ("\n");
}
+/* Parse EXP and show the info about DCACHE. */
+
static void
-dcache_info (char *exp, int tty)
+dcache_info_1 (DCACHE *dcache, const char *exp)
{
splay_tree_node n;
- int i, refcount, lineno;
+ int i, refcount;
if (exp)
{
char *linestart;
+
i = strtol (exp, &linestart, 10);
if (linestart == exp || i < 0)
{
return;
}
- dcache_print_line (i);
+ dcache_print_line (dcache, i);
return;
}
- printf_filtered (_("Dcache line width %d, maximum size %d\n"),
- LINE_SIZE, DCACHE_SIZE);
+ printf_filtered (_("Dcache %u lines of %u bytes each.\n"),
+ dcache_size,
+ dcache ? (unsigned) dcache->line_size
+ : dcache_line_size);
- if (!last_cache || ptid_equal (last_cache->ptid, null_ptid))
+ if (dcache == NULL || ptid_equal (dcache->ptid, null_ptid))
{
printf_filtered (_("No data cache available.\n"));
return;
}
printf_filtered (_("Contains data for %s\n"),
- target_pid_to_str (last_cache->ptid));
+ target_pid_to_str (dcache->ptid));
refcount = 0;
- n = splay_tree_min (last_cache->tree);
+ n = splay_tree_min (dcache->tree);
i = 0;
while (n)
struct dcache_block *db = (struct dcache_block *) n->value;
printf_filtered (_("Line %d: address %s [%d hits]\n"),
- i, paddress (target_gdbarch, db->addr), db->refs);
+ i, paddress (target_gdbarch (), db->addr), db->refs);
i++;
refcount += db->refs;
- n = splay_tree_successor (last_cache->tree, n->key);
+ n = splay_tree_successor (dcache->tree, n->key);
}
printf_filtered (_("Cache state: %d active lines, %d hits\n"), i, refcount);
}
+static void
+info_dcache_command (const char *exp, int tty)
+{
+ dcache_info_1 (target_dcache_get (), exp);
+}
+
+static void
+set_dcache_size (const char *args, int from_tty,
+ struct cmd_list_element *c)
+{
+ if (dcache_size == 0)
+ {
+ dcache_size = DCACHE_DEFAULT_SIZE;
+ error (_("Dcache size must be greater than 0."));
+ }
+ target_dcache_invalidate ();
+}
+
+static void
+set_dcache_line_size (const char *args, int from_tty,
+ struct cmd_list_element *c)
+{
+ if (dcache_line_size < 2
+ || (dcache_line_size & (dcache_line_size - 1)) != 0)
+ {
+ unsigned d = dcache_line_size;
+ dcache_line_size = DCACHE_DEFAULT_LINE_SIZE;
+ error (_("Invalid dcache line size: %u (must be power of 2)."), d);
+ }
+ target_dcache_invalidate ();
+}
+
+static void
+set_dcache_command (const char *arg, int from_tty)
+{
+ printf_unfiltered (
+ "\"set dcache\" must be followed by the name of a subcommand.\n");
+ help_list (dcache_set_list, "set dcache ", all_commands, gdb_stdout);
+}
+
+static void
+show_dcache_command (const char *args, int from_tty)
+{
+ cmd_show_list (dcache_show_list, from_tty, "");
+}
+
void
_initialize_dcache (void)
{
show_dcache_enabled_p,
&setlist, &showlist);
- add_info ("dcache", dcache_info,
+ add_info ("dcache", info_dcache_command,
_("\
Print information on the dcache performance.\n\
With no arguments, this command prints the cache configuration and a\n\
summary of each line in the cache. Use \"info dcache <lineno> to dump\"\n\
the contents of a given line."));
+
+ add_prefix_cmd ("dcache", class_obscure, set_dcache_command, _("\
+Use this command to set number of lines in dcache and line-size."),
+ &dcache_set_list, "set dcache ", /*allow_unknown*/0, &setlist);
+ add_prefix_cmd ("dcache", class_obscure, show_dcache_command, _("\
+Show dcachesettings."),
+ &dcache_show_list, "show dcache ", /*allow_unknown*/0, &showlist);
+
+ add_setshow_zuinteger_cmd ("line-size", class_obscure,
+ &dcache_line_size, _("\
+Set dcache line size in bytes (must be power of 2)."), _("\
+Show dcache line size."),
+ NULL,
+ set_dcache_line_size,
+ NULL,
+ &dcache_set_list, &dcache_show_list);
+ add_setshow_zuinteger_cmd ("size", class_obscure,
+ &dcache_size, _("\
+Set number of dcache lines."), _("\
+Show number of dcache lines."),
+ NULL,
+ set_dcache_size,
+ NULL,
+ &dcache_set_list, &dcache_show_list);
}
projects / deliverable / binutils-gdb.git / blobdiff