-/*
- * The configuration for a particular BTS hardware implementation.
- */
-struct bts_configuration {
- /* the size of a BTS record in bytes; at most BTS_MAX_RECORD_SIZE */
- unsigned char sizeof_bts;
- /* the size of a field in the BTS record in bytes */
- unsigned char sizeof_field;
- /* a bitmask to enable/disable BTS in DEBUGCTL MSR */
- unsigned long debugctl_mask;
-};
-static struct bts_configuration bts_cfg;
-
-#define BTS_MAX_RECORD_SIZE (8 * 3)
-
-
-/*
- * Branch Trace Store (BTS) uses the following format. Different
- * architectures vary in the size of those fields.
- * - source linear address
- * - destination linear address
- * - flags
- *
- * Later architectures use 64bit pointers throughout, whereas earlier
- * architectures use 32bit pointers in 32bit mode.
- *
- * We compute the base address for the first 8 fields based on:
- * - the field size stored in the DS configuration
- * - the relative field position
- *
- * In order to store additional information in the BTS buffer, we use
- * a special source address to indicate that the record requires
- * special interpretation.
- *
- * Netburst indicated via a bit in the flags field whether the branch
- * was predicted; this is ignored.
- */
-
-enum bts_field {
- bts_from = 0,
- bts_to,
- bts_flags,
-
- bts_escape = (unsigned long)-1,
- bts_qual = bts_to,
- bts_jiffies = bts_flags
-};
-
-static inline unsigned long bts_get(const char *base, enum bts_field field)
-{
- base += (bts_cfg.sizeof_field * field);
- return *(unsigned long *)base;
-}
-
-static inline void bts_set(char *base, enum bts_field field, unsigned long val)
-{
- base += (bts_cfg.sizeof_field * field);;
- (*(unsigned long *)base) = val;
-}
-
-/*
- * Translate a BTS record from the raw format into the bts_struct format
- *
- * out (out): bts_struct interpretation
- * raw: raw BTS record
- */
-static void ptrace_bts_translate_record(struct bts_struct *out, const void *raw)
-{
- memset(out, 0, sizeof(*out));
- if (bts_get(raw, bts_from) == bts_escape) {
- out->qualifier = bts_get(raw, bts_qual);
- out->variant.jiffies = bts_get(raw, bts_jiffies);
- } else {
- out->qualifier = BTS_BRANCH;
- out->variant.lbr.from_ip = bts_get(raw, bts_from);
- out->variant.lbr.to_ip = bts_get(raw, bts_to);
- }
-}
-