aboutsummaryrefslogtreecommitdiff
path: root/arch/x86/kernel/ds.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/ds.c')
-rw-r--r--arch/x86/kernel/ds.c464
1 files changed, 0 insertions, 464 deletions
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
deleted file mode 100644
index dcd918c1580..00000000000
--- a/arch/x86/kernel/ds.c
+++ /dev/null
@@ -1,464 +0,0 @@
-/*
- * Debug Store support
- *
- * This provides a low-level interface to the hardware's Debug Store
- * feature that is used for last branch recording (LBR) and
- * precise-event based sampling (PEBS).
- *
- * Different architectures use a different DS layout/pointer size.
- * The below functions therefore work on a void*.
- *
- *
- * Since there is no user for PEBS, yet, only LBR (or branch
- * trace store, BTS) is supported.
- *
- *
- * Copyright (C) 2007 Intel Corporation.
- * Markus Metzger <markus.t.metzger@intel.com>, Dec 2007
- */
-
-#include <asm/ds.h>
-
-#include <linux/errno.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-
-
-/*
- * Debug Store (DS) save area configuration (see Intel64 and IA32
- * Architectures Software Developer's Manual, section 18.5)
- *
- * The DS configuration consists of the following fields; different
- * architetures vary in the size of those fields.
- * - double-word aligned base linear address of the BTS buffer
- * - write pointer into the BTS buffer
- * - end linear address of the BTS buffer (one byte beyond the end of
- * the buffer)
- * - interrupt pointer into BTS buffer
- * (interrupt occurs when write pointer passes interrupt pointer)
- * - double-word aligned base linear address of the PEBS buffer
- * - write pointer into the PEBS buffer
- * - end linear address of the PEBS buffer (one byte beyond the end of
- * the buffer)
- * - interrupt pointer into PEBS buffer
- * (interrupt occurs when write pointer passes interrupt pointer)
- * - value to which counter is reset following counter overflow
- *
- * On later architectures, the last branch recording hardware uses
- * 64bit pointers even in 32bit mode.
- *
- *
- * Branch Trace Store (BTS) records store information about control
- * flow changes. They at least provide the following information:
- * - source linear address
- * - destination linear address
- *
- * Netburst supported a predicated bit that had been dropped in later
- * architectures. We do not suppor it.
- *
- *
- * In order to abstract from the actual DS and BTS layout, we describe
- * the access to the relevant fields.
- * Thanks to Andi Kleen for proposing this design.
- *
- * The implementation, however, is not as general as it might seem. In
- * order to stay somewhat simple and efficient, we assume an
- * underlying unsigned type (mostly a pointer type) and we expect the
- * field to be at least as big as that type.
- */
-
-/*
- * A special from_ip address to indicate that the BTS record is an
- * info record that needs to be interpreted or skipped.
- */
-#define BTS_ESCAPE_ADDRESS (-1)
-
-/*
- * A field access descriptor
- */
-struct access_desc {
- unsigned char offset;
- unsigned char size;
-};
-
-/*
- * The configuration for a particular DS/BTS hardware implementation.
- */
-struct ds_configuration {
- /* the DS configuration */
- unsigned char sizeof_ds;
- struct access_desc bts_buffer_base;
- struct access_desc bts_index;
- struct access_desc bts_absolute_maximum;
- struct access_desc bts_interrupt_threshold;
- /* the BTS configuration */
- unsigned char sizeof_bts;
- struct access_desc from_ip;
- struct access_desc to_ip;
- /* BTS variants used to store additional information like
- timestamps */
- struct access_desc info_type;
- struct access_desc info_data;
- unsigned long debugctl_mask;
-};
-
-/*
- * The global configuration used by the below accessor functions
- */
-static struct ds_configuration ds_cfg;
-
-/*
- * Accessor functions for some DS and BTS fields using the above
- * global ptrace_bts_cfg.
- */
-static inline unsigned long get_bts_buffer_base(char *base)
-{
- return *(unsigned long *)(base + ds_cfg.bts_buffer_base.offset);
-}
-static inline void set_bts_buffer_base(char *base, unsigned long value)
-{
- (*(unsigned long *)(base + ds_cfg.bts_buffer_base.offset)) = value;
-}
-static inline unsigned long get_bts_index(char *base)
-{
- return *(unsigned long *)(base + ds_cfg.bts_index.offset);
-}
-static inline void set_bts_index(char *base, unsigned long value)
-{
- (*(unsigned long *)(base + ds_cfg.bts_index.offset)) = value;
-}
-static inline unsigned long get_bts_absolute_maximum(char *base)
-{
- return *(unsigned long *)(base + ds_cfg.bts_absolute_maximum.offset);
-}
-static inline void set_bts_absolute_maximum(char *base, unsigned long value)
-{
- (*(unsigned long *)(base + ds_cfg.bts_absolute_maximum.offset)) = value;
-}
-static inline unsigned long get_bts_interrupt_threshold(char *base)
-{
- return *(unsigned long *)(base + ds_cfg.bts_interrupt_threshold.offset);
-}
-static inline void set_bts_interrupt_threshold(char *base, unsigned long value)
-{
- (*(unsigned long *)(base + ds_cfg.bts_interrupt_threshold.offset)) = value;
-}
-static inline unsigned long get_from_ip(char *base)
-{
- return *(unsigned long *)(base + ds_cfg.from_ip.offset);
-}
-static inline void set_from_ip(char *base, unsigned long value)
-{
- (*(unsigned long *)(base + ds_cfg.from_ip.offset)) = value;
-}
-static inline unsigned long get_to_ip(char *base)
-{
- return *(unsigned long *)(base + ds_cfg.to_ip.offset);
-}
-static inline void set_to_ip(char *base, unsigned long value)
-{
- (*(unsigned long *)(base + ds_cfg.to_ip.offset)) = value;
-}
-static inline unsigned char get_info_type(char *base)
-{
- return *(unsigned char *)(base + ds_cfg.info_type.offset);
-}
-static inline void set_info_type(char *base, unsigned char value)
-{
- (*(unsigned char *)(base + ds_cfg.info_type.offset)) = value;
-}
-static inline unsigned long get_info_data(char *base)
-{
- return *(unsigned long *)(base + ds_cfg.info_data.offset);
-}
-static inline void set_info_data(char *base, unsigned long value)
-{
- (*(unsigned long *)(base + ds_cfg.info_data.offset)) = value;
-}
-
-
-int ds_allocate(void **dsp, size_t bts_size_in_bytes)
-{
- size_t bts_size_in_records;
- unsigned long bts;
- void *ds;
-
- if (!ds_cfg.sizeof_ds || !ds_cfg.sizeof_bts)
- return -EOPNOTSUPP;
-
- if (bts_size_in_bytes < 0)
- return -EINVAL;
-
- bts_size_in_records =
- bts_size_in_bytes / ds_cfg.sizeof_bts;
- bts_size_in_bytes =
- bts_size_in_records * ds_cfg.sizeof_bts;
-
- if (bts_size_in_bytes <= 0)
- return -EINVAL;
-
- bts = (unsigned long)kzalloc(bts_size_in_bytes, GFP_KERNEL);
-
- if (!bts)
- return -ENOMEM;
-
- ds = kzalloc(ds_cfg.sizeof_ds, GFP_KERNEL);
-
- if (!ds) {
- kfree((void *)bts);
- return -ENOMEM;
- }
-
- set_bts_buffer_base(ds, bts);
- set_bts_index(ds, bts);
- set_bts_absolute_maximum(ds, bts + bts_size_in_bytes);
- set_bts_interrupt_threshold(ds, bts + bts_size_in_bytes + 1);
-
- *dsp = ds;
- return 0;
-}
-
-int ds_free(void **dsp)
-{
- if (*dsp)
- kfree((void *)get_bts_buffer_base(*dsp));
- kfree(*dsp);
- *dsp = NULL;
-
- return 0;
-}
-
-int ds_get_bts_size(void *ds)
-{
- int size_in_bytes;
-
- if (!ds_cfg.sizeof_ds || !ds_cfg.sizeof_bts)
- return -EOPNOTSUPP;
-
- if (!ds)
- return 0;
-
- size_in_bytes =
- get_bts_absolute_maximum(ds) -
- get_bts_buffer_base(ds);
- return size_in_bytes;
-}
-
-int ds_get_bts_end(void *ds)
-{
- int size_in_bytes = ds_get_bts_size(ds);
-
- if (size_in_bytes <= 0)
- return size_in_bytes;
-
- return size_in_bytes / ds_cfg.sizeof_bts;
-}
-
-int ds_get_bts_index(void *ds)
-{
- int index_offset_in_bytes;
-
- if (!ds_cfg.sizeof_ds || !ds_cfg.sizeof_bts)
- return -EOPNOTSUPP;
-
- index_offset_in_bytes =
- get_bts_index(ds) -
- get_bts_buffer_base(ds);
-
- return index_offset_in_bytes / ds_cfg.sizeof_bts;
-}
-
-int ds_set_overflow(void *ds, int method)
-{
- switch (method) {
- case DS_O_SIGNAL:
- return -EOPNOTSUPP;
- case DS_O_WRAP:
- return 0;
- default:
- return -EINVAL;
- }
-}
-
-int ds_get_overflow(void *ds)
-{
- return DS_O_WRAP;
-}
-
-int ds_clear(void *ds)
-{
- int bts_size = ds_get_bts_size(ds);
- unsigned long bts_base;
-
- if (bts_size <= 0)
- return bts_size;
-
- bts_base = get_bts_buffer_base(ds);
- memset((void *)bts_base, 0, bts_size);
-
- set_bts_index(ds, bts_base);
- return 0;
-}
-
-int ds_read_bts(void *ds, int index, struct bts_struct *out)
-{
- void *bts;
-
- if (!ds_cfg.sizeof_ds || !ds_cfg.sizeof_bts)
- return -EOPNOTSUPP;
-
- if (index < 0)
- return -EINVAL;
-
- if (index >= ds_get_bts_size(ds))
- return -EINVAL;
-
- bts = (void *)(get_bts_buffer_base(ds) + (index * ds_cfg.sizeof_bts));
-
- memset(out, 0, sizeof(*out));
- if (get_from_ip(bts) == BTS_ESCAPE_ADDRESS) {
- out->qualifier = get_info_type(bts);
- out->variant.jiffies = get_info_data(bts);
- } else {
- out->qualifier = BTS_BRANCH;
- out->variant.lbr.from_ip = get_from_ip(bts);
- out->variant.lbr.to_ip = get_to_ip(bts);
- }
-
- return sizeof(*out);;
-}
-
-int ds_write_bts(void *ds, const struct bts_struct *in)
-{
- unsigned long bts;
-
- if (!ds_cfg.sizeof_ds || !ds_cfg.sizeof_bts)
- return -EOPNOTSUPP;
-
- if (ds_get_bts_size(ds) <= 0)
- return -ENXIO;
-
- bts = get_bts_index(ds);
-
- memset((void *)bts, 0, ds_cfg.sizeof_bts);
- switch (in->qualifier) {
- case BTS_INVALID:
- break;
-
- case BTS_BRANCH:
- set_from_ip((void *)bts, in->variant.lbr.from_ip);
- set_to_ip((void *)bts, in->variant.lbr.to_ip);
- break;
-
- case BTS_TASK_ARRIVES:
- case BTS_TASK_DEPARTS:
- set_from_ip((void *)bts, BTS_ESCAPE_ADDRESS);
- set_info_type((void *)bts, in->qualifier);
- set_info_data((void *)bts, in->variant.jiffies);
- break;
-
- default:
- return -EINVAL;
- }
-
- bts = bts + ds_cfg.sizeof_bts;
- if (bts >= get_bts_absolute_maximum(ds))
- bts = get_bts_buffer_base(ds);
- set_bts_index(ds, bts);
-
- return ds_cfg.sizeof_bts;
-}
-
-unsigned long ds_debugctl_mask(void)
-{
- return ds_cfg.debugctl_mask;
-}
-
-#ifdef __i386__
-static const struct ds_configuration ds_cfg_netburst = {
- .sizeof_ds = 9 * 4,
- .bts_buffer_base = { 0, 4 },
- .bts_index = { 4, 4 },
- .bts_absolute_maximum = { 8, 4 },
- .bts_interrupt_threshold = { 12, 4 },
- .sizeof_bts = 3 * 4,
- .from_ip = { 0, 4 },
- .to_ip = { 4, 4 },
- .info_type = { 4, 1 },
- .info_data = { 8, 4 },
- .debugctl_mask = (1<<2)|(1<<3)
-};
-
-static const struct ds_configuration ds_cfg_pentium_m = {
- .sizeof_ds = 9 * 4,
- .bts_buffer_base = { 0, 4 },
- .bts_index = { 4, 4 },
- .bts_absolute_maximum = { 8, 4 },
- .bts_interrupt_threshold = { 12, 4 },
- .sizeof_bts = 3 * 4,
- .from_ip = { 0, 4 },
- .to_ip = { 4, 4 },
- .info_type = { 4, 1 },
- .info_data = { 8, 4 },
- .debugctl_mask = (1<<6)|(1<<7)
-};
-#endif /* _i386_ */
-
-static const struct ds_configuration ds_cfg_core2 = {
- .sizeof_ds = 9 * 8,
- .bts_buffer_base = { 0, 8 },
- .bts_index = { 8, 8 },
- .bts_absolute_maximum = { 16, 8 },
- .bts_interrupt_threshold = { 24, 8 },
- .sizeof_bts = 3 * 8,
- .from_ip = { 0, 8 },
- .to_ip = { 8, 8 },
- .info_type = { 8, 1 },
- .info_data = { 16, 8 },
- .debugctl_mask = (1<<6)|(1<<7)|(1<<9)
-};
-
-static inline void
-ds_configure(const struct ds_configuration *cfg)
-{
- ds_cfg = *cfg;
-}
-
-void __cpuinit ds_init_intel(struct cpuinfo_x86 *c)
-{
- switch (c->x86) {
- case 0x6:
- switch (c->x86_model) {
-#ifdef __i386__
- case 0xD:
- case 0xE: /* Pentium M */
- ds_configure(&ds_cfg_pentium_m);
- break;
-#endif /* _i386_ */
- case 0xF: /* Core2 */
- ds_configure(&ds_cfg_core2);
- break;
- default:
- /* sorry, don't know about them */
- break;
- }
- break;
- case 0xF:
- switch (c->x86_model) {
-#ifdef __i386__
- case 0x0:
- case 0x1:
- case 0x2: /* Netburst */
- ds_configure(&ds_cfg_netburst);
- break;
-#endif /* _i386_ */
- default:
- /* sorry, don't know about them */
- break;
- }
- break;
- default:
- /* sorry, don't know about them */
- break;
- }
-}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-10 15:34:01 +0000