summaryrefslogtreecommitdiff
path: root/arch/x86/include/asm/ds.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/include/asm/ds.h')
-rw-r--r--arch/x86/include/asm/ds.h134
1 files changed, 60 insertions, 74 deletions
diff --git a/arch/x86/include/asm/ds.h b/arch/x86/include/asm/ds.h
index a95008457ea4..99b6c39774a4 100644
--- a/arch/x86/include/asm/ds.h
+++ b/arch/x86/include/asm/ds.h
@@ -7,13 +7,12 @@
*
* It manages:
* - per-thread and per-cpu allocation of BTS and PEBS
- * - buffer memory allocation (optional)
- * - buffer overflow handling
+ * - buffer overflow handling (to be done)
* - buffer access
*
* It assumes:
- * - get_task_struct on all parameter tasks
- * - current is allowed to trace parameter tasks
+ * - get_task_struct on all traced tasks
+ * - current is allowed to trace tasks
*
*
* Copyright (C) 2007-2008 Intel Corporation.
@@ -26,11 +25,18 @@
#include <linux/types.h>
#include <linux/init.h>
+#include <linux/err.h>
#ifdef CONFIG_X86_DS
struct task_struct;
+struct ds_tracer;
+struct bts_tracer;
+struct pebs_tracer;
+
+typedef void (*bts_ovfl_callback_t)(struct bts_tracer *);
+typedef void (*pebs_ovfl_callback_t)(struct pebs_tracer *);
/*
* Request BTS or PEBS
@@ -38,60 +44,62 @@ struct task_struct;
* Due to alignement constraints, the actual buffer may be slightly
* smaller than the requested or provided buffer.
*
- * Returns 0 on success; -Eerrno otherwise
+ * Returns a pointer to a tracer structure on success, or
+ * ERR_PTR(errcode) on failure.
+ *
+ * The interrupt threshold is independent from the overflow callback
+ * to allow users to use their own overflow interrupt handling mechanism.
*
* task: the task to request recording for;
* NULL for per-cpu recording on the current cpu
* base: the base pointer for the (non-pageable) buffer;
- * NULL if buffer allocation requested
- * size: the size of the requested or provided buffer
+ * size: the size of the provided buffer in bytes
* ovfl: pointer to a function to be called on buffer overflow;
* NULL if cyclic buffer requested
+ * th: the interrupt threshold in records from the end of the buffer;
+ * -1 if no interrupt threshold is requested.
*/
-typedef void (*ds_ovfl_callback_t)(struct task_struct *);
-extern int ds_request_bts(struct task_struct *task, void *base, size_t size,
- ds_ovfl_callback_t ovfl);
-extern int ds_request_pebs(struct task_struct *task, void *base, size_t size,
- ds_ovfl_callback_t ovfl);
+extern struct bts_tracer *ds_request_bts(struct task_struct *task,
+ void *base, size_t size,
+ bts_ovfl_callback_t ovfl, size_t th);
+extern struct pebs_tracer *ds_request_pebs(struct task_struct *task,
+ void *base, size_t size,
+ pebs_ovfl_callback_t ovfl,
+ size_t th);
/*
* Release BTS or PEBS resources
*
- * Frees buffers allocated on ds_request.
- *
* Returns 0 on success; -Eerrno otherwise
*
- * task: the task to release resources for;
- * NULL to release resources for the current cpu
+ * tracer: the tracer handle returned from ds_request_~()
*/
-extern int ds_release_bts(struct task_struct *task);
-extern int ds_release_pebs(struct task_struct *task);
+extern int ds_release_bts(struct bts_tracer *tracer);
+extern int ds_release_pebs(struct pebs_tracer *tracer);
/*
- * Return the (array) index of the write pointer.
+ * Get the (array) index of the write pointer.
* (assuming an array of BTS/PEBS records)
*
- * Returns -Eerrno on error
+ * Returns 0 on success; -Eerrno on error
*
- * task: the task to access;
- * NULL to access the current cpu
- * pos (out): if not NULL, will hold the result
+ * tracer: the tracer handle returned from ds_request_~()
+ * pos (out): will hold the result
*/
-extern int ds_get_bts_index(struct task_struct *task, size_t *pos);
-extern int ds_get_pebs_index(struct task_struct *task, size_t *pos);
+extern int ds_get_bts_index(struct bts_tracer *tracer, size_t *pos);
+extern int ds_get_pebs_index(struct pebs_tracer *tracer, size_t *pos);
/*
- * Return the (array) index one record beyond the end of the array.
+ * Get the (array) index one record beyond the end of the array.
* (assuming an array of BTS/PEBS records)
*
- * Returns -Eerrno on error
+ * Returns 0 on success; -Eerrno on error
*
- * task: the task to access;
- * NULL to access the current cpu
- * pos (out): if not NULL, will hold the result
+ * tracer: the tracer handle returned from ds_request_~()
+ * pos (out): will hold the result
*/
-extern int ds_get_bts_end(struct task_struct *task, size_t *pos);
-extern int ds_get_pebs_end(struct task_struct *task, size_t *pos);
+extern int ds_get_bts_end(struct bts_tracer *tracer, size_t *pos);
+extern int ds_get_pebs_end(struct pebs_tracer *tracer, size_t *pos);
/*
* Provide a pointer to the BTS/PEBS record at parameter index.
@@ -102,14 +110,13 @@ extern int ds_get_pebs_end(struct task_struct *task, size_t *pos);
*
* Returns the size of a single record on success; -Eerrno on error
*
- * task: the task to access;
- * NULL to access the current cpu
+ * tracer: the tracer handle returned from ds_request_~()
* index: the index of the requested record
* record (out): pointer to the requested record
*/
-extern int ds_access_bts(struct task_struct *task,
+extern int ds_access_bts(struct bts_tracer *tracer,
size_t index, const void **record);
-extern int ds_access_pebs(struct task_struct *task,
+extern int ds_access_pebs(struct pebs_tracer *tracer,
size_t index, const void **record);
/*
@@ -129,38 +136,24 @@ extern int ds_access_pebs(struct task_struct *task,
*
* Returns the number of bytes written or -Eerrno.
*
- * task: the task to access;
- * NULL to access the current cpu
+ * tracer: the tracer handle returned from ds_request_~()
* buffer: the buffer to write
* size: the size of the buffer
*/
-extern int ds_write_bts(struct task_struct *task,
+extern int ds_write_bts(struct bts_tracer *tracer,
const void *buffer, size_t size);
-extern int ds_write_pebs(struct task_struct *task,
+extern int ds_write_pebs(struct pebs_tracer *tracer,
const void *buffer, size_t size);
/*
- * Same as ds_write_bts/pebs, but omit ownership checks.
- *
- * This is needed to have some other task than the owner of the
- * BTS/PEBS buffer or the parameter task itself write into the
- * respective buffer.
- */
-extern int ds_unchecked_write_bts(struct task_struct *task,
- const void *buffer, size_t size);
-extern int ds_unchecked_write_pebs(struct task_struct *task,
- const void *buffer, size_t size);
-
-/*
* Reset the write pointer of the BTS/PEBS buffer.
*
* Returns 0 on success; -Eerrno on error
*
- * task: the task to access;
- * NULL to access the current cpu
+ * tracer: the tracer handle returned from ds_request_~()
*/
-extern int ds_reset_bts(struct task_struct *task);
-extern int ds_reset_pebs(struct task_struct *task);
+extern int ds_reset_bts(struct bts_tracer *tracer);
+extern int ds_reset_pebs(struct pebs_tracer *tracer);
/*
* Clear the BTS/PEBS buffer and reset the write pointer.
@@ -168,33 +161,30 @@ extern int ds_reset_pebs(struct task_struct *task);
*
* Returns 0 on success; -Eerrno on error
*
- * task: the task to access;
- * NULL to access the current cpu
+ * tracer: the tracer handle returned from ds_request_~()
*/
-extern int ds_clear_bts(struct task_struct *task);
-extern int ds_clear_pebs(struct task_struct *task);
+extern int ds_clear_bts(struct bts_tracer *tracer);
+extern int ds_clear_pebs(struct pebs_tracer *tracer);
/*
* Provide the PEBS counter reset value.
*
* Returns 0 on success; -Eerrno on error
*
- * task: the task to access;
- * NULL to access the current cpu
+ * tracer: the tracer handle returned from ds_request_pebs()
* value (out): the counter reset value
*/
-extern int ds_get_pebs_reset(struct task_struct *task, u64 *value);
+extern int ds_get_pebs_reset(struct pebs_tracer *tracer, u64 *value);
/*
* Set the PEBS counter reset value.
*
* Returns 0 on success; -Eerrno on error
*
- * task: the task to access;
- * NULL to access the current cpu
+ * tracer: the tracer handle returned from ds_request_pebs()
* value: the new counter reset value
*/
-extern int ds_set_pebs_reset(struct task_struct *task, u64 value);
+extern int ds_set_pebs_reset(struct pebs_tracer *tracer, u64 value);
/*
* Initialization
@@ -207,17 +197,13 @@ extern void __cpuinit ds_init_intel(struct cpuinfo_x86 *);
/*
* The DS context - part of struct thread_struct.
*/
+#define MAX_SIZEOF_DS (12 * 8)
+
struct ds_context {
/* pointer to the DS configuration; goes into MSR_IA32_DS_AREA */
- unsigned char *ds;
+ unsigned char ds[MAX_SIZEOF_DS];
/* the owner of the BTS and PEBS configuration, respectively */
- struct task_struct *owner[2];
- /* buffer overflow notification function for BTS and PEBS */
- ds_ovfl_callback_t callback[2];
- /* the original buffer address */
- void *buffer[2];
- /* the number of allocated pages for on-request allocated buffers */
- unsigned int pages[2];
+ struct ds_tracer *owner[2];
/* use count */
unsigned long count;
/* a pointer to the context location inside the thread_struct