#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
{
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
/* 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;
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)
+{
+ 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);
+}
+
+
/* 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;
{
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 = 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;
}
struct dcache_block *db = dcache_hit (dcache, addr);
if (db)
- db->data[XFORM (addr)] = *ptr;
+ db->data[XFORM (dcache, addr)] = *ptr;
return 1;
}
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
printf_filtered (_("Line %d: address %s [%d hits]\n"),
index, paddress (target_gdbarch, db->addr), db->refs);
- for (j = 0; j < LINE_SIZE; j++)
+ for (j = 0; j < last_cache->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))
+ if ((j % 16 == 15) && (j != last_cache->line_size - 1))
printf_filtered ("\n");
}
printf_filtered ("\n");
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,
+ last_cache ? (unsigned) last_cache->line_size
+ : dcache_line_size);
if (!last_cache || ptid_equal (last_cache->ptid, null_ptid))
{
printf_filtered (_("Cache state: %d active lines, %d hits\n"), i, refcount);
}
+static void
+set_dcache_size (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."));
+ }
+ if (last_cache)
+ dcache_invalidate (last_cache);
+}
+
+static void
+set_dcache_line_size (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);
+ }
+ if (last_cache)
+ dcache_invalidate (last_cache);
+}
+
+static void
+set_dcache_command (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 ", -1, gdb_stdout);
+}
+
+static void
+show_dcache_command (char *args, int from_tty)
+{
+ cmd_show_list (dcache_show_list, from_tty, "");
+}
+
void
_initialize_dcache (void)
{
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_uinteger_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_uinteger_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);
}
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