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Commit 4ac945f0 authored by Robert Richter's avatar Robert Richter
Browse files

oprofile, x86: Check IBS capability bits 1 and 2 

There are IBS CPUID feature flags in CPUID Fn8000_001B to detect if
the cpu supports IBS fetch sampling (FetchSam) and/or IBS execution
sampling (OpSam). This patch adds checks if the both features are
available.

Spec:

 http://support.amd.com/us/Processor_TechDocs/31116.pdf



Signed-off-by: default avatarRobert Richter <robert.richter@amd.com>
parent e6341474

arch/x86/oprofile/op_model_amd.c

+38 −21
Original line number Diff line number Diff line
@@ -70,9 +70,22 @@ static u64 ibs_op_ctl; 
 * Same bit mask as for IBS cpuid feature flags (Fn8000_001B_EAX), but

 * bit 0 is used to indicate the existence of IBS.

 */

#define IBS_CAPS_AVAIL			(1LL<<0)

#define IBS_CAPS_RDWROPCNT		(1LL<<3)

#define IBS_CAPS_OPCNT			(1LL<<4)

#define IBS_CAPS_AVAIL			(1U<<0)

#define IBS_CAPS_FETCHSAM		(1U<<1)

#define IBS_CAPS_OPSAM			(1U<<2)

#define IBS_CAPS_RDWROPCNT		(1U<<3)

#define IBS_CAPS_OPCNT			(1U<<4)



#define IBS_CAPS_DEFAULT		(IBS_CAPS_AVAIL		\

					 | IBS_CAPS_FETCHSAM	\

					 | IBS_CAPS_OPSAM)



/*

 * IBS APIC setup

 */

#define IBSCTL				0x1cc

#define IBSCTL_LVT_OFFSET_VALID		(1ULL<<8)

#define IBSCTL_LVT_OFFSET_MASK		0x0F



/*

 * IBS randomization macros
@@ -92,12 +105,12 @@ static u32 get_ibs_caps(void) 
	/* check IBS cpuid feature flags */

	max_level = cpuid_eax(0x80000000);

	if (max_level < IBS_CPUID_FEATURES)

		return IBS_CAPS_AVAIL;

		return IBS_CAPS_DEFAULT;



	ibs_caps = cpuid_eax(IBS_CPUID_FEATURES);

	if (!(ibs_caps & IBS_CAPS_AVAIL))

		/* cpuid flags not valid */

		return IBS_CAPS_AVAIL;

		return IBS_CAPS_DEFAULT;



	return ibs_caps;

}
@@ -527,6 +540,7 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root) 
	ibs_config.op_enabled = 0;

	ibs_config.dispatched_ops = 0;



	if (ibs_caps & IBS_CAPS_FETCHSAM) {

		dir = oprofilefs_mkdir(sb, root, "ibs_fetch");

		oprofilefs_create_ulong(sb, dir, "enable",

					&ibs_config.fetch_enabled);
@@ -534,7 +548,9 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root) 
					&ibs_config.max_cnt_fetch);

		oprofilefs_create_ulong(sb, dir, "rand_enable",

					&ibs_config.rand_en);

	}



	if (ibs_caps & IBS_CAPS_OPSAM) {

		dir = oprofilefs_mkdir(sb, root, "ibs_op");

		oprofilefs_create_ulong(sb, dir, "enable",

					&ibs_config.op_enabled);
@@ -543,6 +559,7 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root) 
		if (ibs_caps & IBS_CAPS_OPCNT)

			oprofilefs_create_ulong(sb, dir, "dispatched_ops",

						&ibs_config.dispatched_ops);

	}



	return 0;

}