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Commit 1d9807fc authored by Tony Luck's avatar Tony Luck Committed by Thomas Gleixner
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x86/intel_rdt: Add command line options for resource director technology 



Command line options allow us to ignore features that we don't want.
Also we can re-enable options that have been disabled on a platform
(so long as the underlying h/w actually supports the option).

[ tglx: Marked the option array __initdata and the helper function __init ]

Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Fenghua" <fenghua.yu@intel.com>
Cc: Ravi V" <ravi.v.shankar@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Andi Kleen" <ak@linux.intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Link: http://lkml.kernel.org/r/0c37b0d4dbc30977a3c1cee08b66420f83662694.1503512900.git.tony.luck@intel.com
parent 0576113a

Documentation/admin-guide/kernel-parameters.rst

+1 −0
Original line number Diff line number Diff line
@@ -138,6 +138,7 @@ parameter is applicable:: 
	PPT	Parallel port support is enabled.

	PS2	Appropriate PS/2 support is enabled.

	RAM	RAM disk support is enabled.

	RDT	Intel Resource Director Technology.

	S390	S390 architecture is enabled.

	SCSI	Appropriate SCSI support is enabled.

			A lot of drivers have their options described inside

Documentation/admin-guide/kernel-parameters.txt

+6 −0
Original line number Diff line number Diff line
@@ -3598,6 +3598,12 @@ 
			Run specified binary instead of /init from the ramdisk,

			used for early userspace startup. See initrd.



	rdt=		[HW,X86,RDT]

			Turn on/off individual RDT features. List is:

			cmt, mbmtotal, mbmlocal, l3cat, l3cdp, l2cat, mba.

			E.g. to turn on cmt and turn off mba use:

				rdt=cmt,!mba



	reboot=		[KNL]

			Format (x86 or x86_64):

				[w[arm] | c[old] | h[ard] | s[oft] | g[pio]] \

arch/x86/kernel/cpu/intel_rdt.c

+88 −8
Original line number Diff line number Diff line
@@ -637,6 +637,85 @@ static __init void rdt_init_padding(void) 
	}

}



enum {

	RDT_FLAG_CMT,

	RDT_FLAG_MBM_TOTAL,

	RDT_FLAG_MBM_LOCAL,

	RDT_FLAG_L3_CAT,

	RDT_FLAG_L3_CDP,

	RDT_FLAG_L2_CAT,

	RDT_FLAG_MBA,

};



#define RDT_OPT(idx, n, f)	\

[idx] = {			\

	.name = n,		\

	.flag = f		\

}



struct rdt_options {

	char	*name;

	int	flag;

	bool	force_off, force_on;

};



static struct rdt_options rdt_options[]  __initdata = {

	RDT_OPT(RDT_FLAG_CMT,	    "cmt",	X86_FEATURE_CQM_OCCUP_LLC),

	RDT_OPT(RDT_FLAG_MBM_TOTAL, "mbmtotal", X86_FEATURE_CQM_MBM_TOTAL),

	RDT_OPT(RDT_FLAG_MBM_LOCAL, "mbmlocal", X86_FEATURE_CQM_MBM_LOCAL),

	RDT_OPT(RDT_FLAG_L3_CAT,    "l3cat",	X86_FEATURE_CAT_L3),

	RDT_OPT(RDT_FLAG_L3_CDP,    "l3cdp",	X86_FEATURE_CDP_L3),

	RDT_OPT(RDT_FLAG_L2_CAT,    "l2cat",	X86_FEATURE_CAT_L2),

	RDT_OPT(RDT_FLAG_MBA,	    "mba",	X86_FEATURE_MBA),

};

#define NUM_RDT_OPTIONS ARRAY_SIZE(rdt_options)



static int __init set_rdt_options(char *str)

{

	struct rdt_options *o;

	bool force_off;

	char *tok;



	if (*str == '=')

		str++;

	while ((tok = strsep(&str, ",")) != NULL) {

		force_off = *tok == '!';

		if (force_off)

			tok++;

		for (o = rdt_options; o < &rdt_options[NUM_RDT_OPTIONS]; o++) {

			if (strcmp(tok, o->name) == 0) {

				if (force_off)

					o->force_off = true;

				else

					o->force_on = true;

				break;

			}

		}

	}

	return 1;

}

__setup("rdt", set_rdt_options);



static bool __init rdt_cpu_has(int flag)

{

	bool ret = boot_cpu_has(flag);

	struct rdt_options *o;



	if (!ret)

		return ret;



	for (o = rdt_options; o < &rdt_options[NUM_RDT_OPTIONS]; o++) {

		if (flag == o->flag) {

			if (o->force_off)

				ret = false;

			if (o->force_on)

				ret = true;

			break;

		}

	}

	return ret;

}



static __init bool get_rdt_alloc_resources(void)

{

	bool ret = false;
@@ -647,21 +726,21 @@ static __init bool get_rdt_alloc_resources(void) 
	if (!boot_cpu_has(X86_FEATURE_RDT_A))

		return false;



	if (boot_cpu_has(X86_FEATURE_CAT_L3)) {

	if (rdt_cpu_has(X86_FEATURE_CAT_L3)) {

		rdt_get_cache_alloc_cfg(1, &rdt_resources_all[RDT_RESOURCE_L3]);

		if (boot_cpu_has(X86_FEATURE_CDP_L3)) {

		if (rdt_cpu_has(X86_FEATURE_CDP_L3)) {

			rdt_get_cdp_l3_config(RDT_RESOURCE_L3DATA);

			rdt_get_cdp_l3_config(RDT_RESOURCE_L3CODE);

		}

		ret = true;

	}

	if (boot_cpu_has(X86_FEATURE_CAT_L2)) {

	if (rdt_cpu_has(X86_FEATURE_CAT_L2)) {

		/* CPUID 0x10.2 fields are same format at 0x10.1 */

		rdt_get_cache_alloc_cfg(2, &rdt_resources_all[RDT_RESOURCE_L2]);

		ret = true;

	}



	if (boot_cpu_has(X86_FEATURE_MBA)) {

	if (rdt_cpu_has(X86_FEATURE_MBA)) {

		if (rdt_get_mem_config(&rdt_resources_all[RDT_RESOURCE_MBA]))

			ret = true;

	}
@@ -670,11 +749,11 @@ static __init bool get_rdt_alloc_resources(void) 


static __init bool get_rdt_mon_resources(void)

{

	if (boot_cpu_has(X86_FEATURE_CQM_OCCUP_LLC))

	if (rdt_cpu_has(X86_FEATURE_CQM_OCCUP_LLC))

		rdt_mon_features |= (1 << QOS_L3_OCCUP_EVENT_ID);

	if (boot_cpu_has(X86_FEATURE_CQM_MBM_TOTAL))

	if (rdt_cpu_has(X86_FEATURE_CQM_MBM_TOTAL))

		rdt_mon_features |= (1 << QOS_L3_MBM_TOTAL_EVENT_ID);

	if (boot_cpu_has(X86_FEATURE_CQM_MBM_LOCAL))

	if (rdt_cpu_has(X86_FEATURE_CQM_MBM_LOCAL))

		rdt_mon_features |= (1 << QOS_L3_MBM_LOCAL_EVENT_ID);



	if (!rdt_mon_features)
@@ -687,6 +766,7 @@ static __init void rdt_quirks(void) 
{

	switch (boot_cpu_data.x86_model) {

	case INTEL_FAM6_HASWELL_X:

		if (!rdt_options[RDT_FLAG_L3_CAT].force_off)

			cache_alloc_hsw_probe();

		break;

	}