Commit 06fcc73c authored by Ze Zuo's avatar Ze Zuo
Browse files

driver/arm/spe: making mem_sampling and perf mutually exclusive with spe driver 

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I9GZAQ


CVE: NA

--------------------------------

The preorder patch constitutes a set of independent SPE drivers, and
isolates the basic operations of SPE from the perf driver, including
SPE interrupt handling, enabling and other operations, so that the use
of SPE functionality can be divided into two categories: the first is
the basic modules of the kernel, such as: Numa Balance, Damon, etc.,
and the second is the use of perf driver by the user, where the The
first type of users The first type of users starts and stops the SPE
through the abstraction layer mem_sampling. in addition, in order to
avoid as much as possible embedded modifications to the perf code, we
introduced the cmdline mem_sampling_on to control the use of
mem_sampling, when the perf spe can not be captured, and vice versa.

Signed-off-by: default avatarZe Zuo <zuoze1@huawei.com>
parent 71ff7aad

drivers/arm/spe/Kconfig

+1 −1
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 
#

config ARM_SPE_MEM_SAMPLING

	bool "In-kernel SPE for driver for page access profiling"

	depends on ARM64 && !ARM_SPE_PMU

	depends on ARM64

        help

	  Enable support for the ARMv8.2 Statistical Profiling Extension, which

	  provides periodic sampling of operations in the CPU pipeline.

drivers/arm/spe/spe.c

+9 −4
Original line number Diff line number Diff line
@@ -700,6 +700,15 @@ static int arm_spe_device_probe(struct platform_device *pdev) 
	int ret;

	struct device *dev = &pdev->dev;



	/*

	 * TODO: Find a clean way to disable SPE so that SPE

	 * can be used for perf.

	 */

	if (!mem_sampling_enabled()) {

		dev_warn_once(dev, "mem_sampling inaccessible. Try passing \"mem_sampling_on\" on the kernel command line\n");

		return -EBUSY;

	}



	/*

	 * If kernelspace is unmapped when running at EL0, then the SPE

	 * buffer will fault and prematurely terminate the AUX session.
@@ -784,10 +793,6 @@ static int __init arm_spe_init(void) 


static void __exit arm_spe_exit(void)

{

	/*

	 * TODO: Find a clean way to disable SPE so that SPE

	 * can be used for perf.

	 */

	platform_driver_unregister(&arm_spe_driver);

	cpuhp_remove_multi_state(arm_spe_online);

	arm_spe_buffer_free();

drivers/perf/arm_spe_pmu.c

+6 −0
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <linux/slab.h>

#include <linux/smp.h>

#include <linux/vmalloc.h>

#include <linux/mem_sampling.h>



#include <asm/barrier.h>

#include <asm/cpufeature.h>
@@ -1199,6 +1200,11 @@ static int arm_spe_pmu_device_probe(struct platform_device *pdev) 
	struct arm_spe_pmu *spe_pmu;

	struct device *dev = &pdev->dev;



	if (mem_sampling_enabled()) {

		dev_warn_once(dev, "perf spe inaccessible. Try removing \"mem_sampling_on\" on the kernel command line\n");

		return -EBUSY;

	}



	/*

	 * If kernelspace is unmapped when running at EL0, then the SPE

	 * buffer will fault and prematurely terminate the AUX session.

include/linux/mem_sampling.h

+9 −0
Original line number Diff line number Diff line
@@ -59,6 +59,15 @@ void mem_sampling_sched_in(struct task_struct *prev, struct task_struct *curr); 
static inline void mem_sampling_sched_in(struct task_struct *prev, struct task_struct *curr) { }

#endif



#ifdef CONFIG_MEM_SAMPLING

bool mem_sampling_enabled(void);

#else

static inline bool mem_sampling_enabled(void)

{

	return false;

}

#endif



/* invoked by specific mem_sampling */

typedef void (*mem_sampling_cb_type)(struct mem_sampling_record *record_base,

				     int n_records);

mm/mem_sampling.c

+16 −0
Original line number Diff line number Diff line
@@ -26,6 +26,8 @@ 


struct mem_sampling_ops_struct mem_sampling_ops;



static int mem_sampling;



#define MEM_SAMPLING_DISABLED		0x0

#define MEM_SAMPLING_NORMAL		0x1

#define NUMA_BALANCING_HW_DISABLED	0x0
@@ -96,6 +98,12 @@ void mem_sampling_sched_in(struct task_struct *prev, struct task_struct *curr) 
		mem_sampling_ops.sampling_stop();

}



bool mem_sampling_enabled(void)

{

	return mem_sampling;

}

EXPORT_SYMBOL_GPL(mem_sampling_enabled);



static void mem_sampling_process(struct mem_sampling_record *record_base, int nr_records)

{

	int i;
@@ -419,6 +427,14 @@ static void __init check_mem_sampling_enable(void) 
		set_mem_sampling_state(mem_sampling_default);

}



static int __init mem_sampling_setup(char *str)

{

	mem_sampling = 1;

	return 1;



}

__setup("mem_sampling_on", mem_sampling_setup);



static int __init mem_sampling_init(void)

{

	enum mem_sampling_type_enum mem_sampling_type = mem_sampling_get_type();