/* Caching code for GDB, the GNU debugger.
- Copyright (C) 1992, 1993, 1995, 1996, 1998, 1999, 2000, 2001, 2003, 2007,
- 2008, 2009, 2010 Free Software Foundation, Inc.
+ Copyright (C) 1992-2020 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"
+#include "gdbarch.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
is set, etc., then the chunk is skipped. Those chunks are handled
in target_xfer_memory() (or target_xfer_memory_partial()).
- This doesn't occur very often. The most common occurance is when
+ This doesn't occur very often. The most common occurrence is when
the last bit of the .text segment and the first bit of the .data
segment fall within the same dcache page with a ro/cacheable memory
region defined for the .text segment and a rw/non-cacheable memory
/* 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_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 bool dcache_enabled_p = false; /* OBSOLETE */
static void
show_dcache_enabled_p (struct ui_file *file, int from_tty,
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;
-
- 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. */
- if (! ptid_equal (inferior_ptid, dcache->ptid))
+ if (inferior_ptid != dcache->ptid)
{
dcache_invalidate (dcache);
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;
if (exp)
{
char *linestart;
+
i = strtol (exp, &linestart, 10);
if (linestart == exp || i < 0)
{
- printf_filtered (_("Usage: info dcache [linenumber]\n"));
+ printf_filtered (_("Usage: info dcache [LINENUMBER]\n"));
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 || 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).c_str ());
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 ();
+}
+
+void _initialize_dcache ();
void
-_initialize_dcache (void)
+_initialize_dcache ()
{
add_setshow_boolean_cmd ("remotecache", class_support,
&dcache_enabled_p, _("\
show_dcache_enabled_p,
&setlist, &showlist);
- add_info ("dcache", dcache_info,
+ add_info ("dcache", info_dcache_command,
_("\
Print information on the dcache performance.\n\
+Usage: info dcache [LINENUMBER]\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."));
+summary of each line in the cache. With an argument, dump\"\n\
+the contents of the given line."));
+
+ add_basic_prefix_cmd ("dcache", class_obscure, _("\
+Use this command to set number of lines in dcache and line-size."),
+ &dcache_set_list, "set dcache ", /*allow_unknown*/0,
+ &setlist);
+ add_show_prefix_cmd ("dcache", class_obscure, _("\
+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