Commit 7d0ec14c authored by James Morse's avatar James Morse Committed by Borislav Petkov (AMD)
Browse files

x86/resctrl: Add resctrl_arch_ prefix to pseudo lock functions 



resctrl's pseudo lock has some copy-to-cache and measurement functions that
are micro-architecture specific.

For example, pseudo_lock_fn() is not at all portable.

Label these 'resctrl_arch_' so they stay under /arch/x86.  To expose these
functions to the filesystem code they need an entry in a header file, and
can't be marked static.

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarShaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: default avatarTony Luck <tony.luck@intel.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Reviewed-by: default avatarFenghua Yu <fenghuay@nvidia.com>
Reviewed-by: default avatarBabu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Tested-by: default avatarShaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: default avatarPeter Newman <peternewman@google.com>
Tested-by: Amit Singh Tomar <amitsinght@marvell.com> # arm64
Tested-by: Shanker Donthineni <sdonthineni@nvidia.com> # arm64
Tested-by: default avatarBabu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20250311183715.16445-24-james.morse@arm.com
parent c32a7d77

arch/x86/include/asm/resctrl.h

+5 −0
Original line number Diff line number Diff line
@@ -203,6 +203,11 @@ static inline void *resctrl_arch_mon_ctx_alloc(struct rdt_resource *r, int evtid 
static inline void resctrl_arch_mon_ctx_free(struct rdt_resource *r, int evtid,

					     void *ctx) { };



u64 resctrl_arch_get_prefetch_disable_bits(void);

int resctrl_arch_pseudo_lock_fn(void *_rdtgrp);

int resctrl_arch_measure_cycles_lat_fn(void *_plr);

int resctrl_arch_measure_l2_residency(void *_plr);

int resctrl_arch_measure_l3_residency(void *_plr);

void resctrl_cpu_detect(struct cpuinfo_x86 *c);



#else

arch/x86/kernel/cpu/resctrl/pseudo_lock.c

+19 −17
Original line number Diff line number Diff line
@@ -61,7 +61,8 @@ static const struct class pseudo_lock_class = { 
};



/**

 * get_prefetch_disable_bits - prefetch disable bits of supported platforms

 * resctrl_arch_get_prefetch_disable_bits - prefetch disable bits of supported

 *                                          platforms

 * @void: It takes no parameters.

 *

 * Capture the list of platforms that have been validated to support
@@ -75,13 +76,13 @@ static const struct class pseudo_lock_class = { 
 * in the SDM.

 *

 * When adding a platform here also add support for its cache events to

 * measure_cycles_perf_fn()

 * resctrl_arch_measure_l*_residency()

 *

 * Return:

 * If platform is supported, the bits to disable hardware prefetchers, 0

 * if platform is not supported.

 */

static u64 get_prefetch_disable_bits(void)

u64 resctrl_arch_get_prefetch_disable_bits(void)

{

	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL ||

	    boot_cpu_data.x86 != 6)
@@ -408,7 +409,7 @@ static void pseudo_lock_free(struct rdtgroup *rdtgrp) 
}



/**

 * pseudo_lock_fn - Load kernel memory into cache

 * resctrl_arch_pseudo_lock_fn - Load kernel memory into cache

 * @_rdtgrp: resource group to which pseudo-lock region belongs

 *

 * This is the core pseudo-locking flow.
@@ -426,7 +427,7 @@ static void pseudo_lock_free(struct rdtgroup *rdtgrp) 
 *

 * Return: 0. Waiter on waitqueue will be woken on completion.

 */

static int pseudo_lock_fn(void *_rdtgrp)

int resctrl_arch_pseudo_lock_fn(void *_rdtgrp)

{

	struct rdtgroup *rdtgrp = _rdtgrp;

	struct pseudo_lock_region *plr = rdtgrp->plr;
@@ -712,7 +713,7 @@ int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp) 
	 * Not knowing the bits to disable prefetching implies that this

	 * platform does not support Cache Pseudo-Locking.

	 */

	prefetch_disable_bits = get_prefetch_disable_bits();

	prefetch_disable_bits = resctrl_arch_get_prefetch_disable_bits();

	if (prefetch_disable_bits == 0) {

		rdt_last_cmd_puts("Pseudo-locking not supported\n");

		return -EINVAL;
@@ -872,7 +873,8 @@ bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d) 
}



/**

 * measure_cycles_lat_fn - Measure cycle latency to read pseudo-locked memory

 * resctrl_arch_measure_cycles_lat_fn - Measure cycle latency to read

 *                                      pseudo-locked memory

 * @_plr: pseudo-lock region to measure

 *

 * There is no deterministic way to test if a memory region is cached. One
@@ -885,7 +887,7 @@ bool rdtgroup_pseudo_locked_in_hierarchy(struct rdt_ctrl_domain *d) 
 *

 * Return: 0. Waiter on waitqueue will be woken on completion.

 */

static int measure_cycles_lat_fn(void *_plr)

int resctrl_arch_measure_cycles_lat_fn(void *_plr)

{

	struct pseudo_lock_region *plr = _plr;

	u32 saved_low, saved_high;
@@ -1069,7 +1071,7 @@ static int measure_residency_fn(struct perf_event_attr *miss_attr, 
	return 0;

}



static int measure_l2_residency(void *_plr)

int resctrl_arch_measure_l2_residency(void *_plr)

{

	struct pseudo_lock_region *plr = _plr;

	struct residency_counts counts = {0};
@@ -1107,7 +1109,7 @@ static int measure_l2_residency(void *_plr) 
	return 0;

}



static int measure_l3_residency(void *_plr)

int resctrl_arch_measure_l3_residency(void *_plr)

{

	struct pseudo_lock_region *plr = _plr;

	struct residency_counts counts = {0};
@@ -1205,14 +1207,14 @@ static int pseudo_lock_measure_cycles(struct rdtgroup *rdtgrp, int sel) 
	plr->cpu = cpu;



	if (sel == 1)

		thread = kthread_run_on_cpu(measure_cycles_lat_fn, plr,

					    cpu, "pseudo_lock_measure/%u");

		thread = kthread_run_on_cpu(resctrl_arch_measure_cycles_lat_fn,

					    plr, cpu, "pseudo_lock_measure/%u");

	else if (sel == 2)

		thread = kthread_run_on_cpu(measure_l2_residency, plr,

					    cpu, "pseudo_lock_measure/%u");

		thread = kthread_run_on_cpu(resctrl_arch_measure_l2_residency,

					    plr, cpu, "pseudo_lock_measure/%u");

	else if (sel == 3)

		thread = kthread_run_on_cpu(measure_l3_residency, plr,

					    cpu, "pseudo_lock_measure/%u");

		thread = kthread_run_on_cpu(resctrl_arch_measure_l3_residency,

					    plr, cpu, "pseudo_lock_measure/%u");

	else

		goto out;
@@ -1307,7 +1309,7 @@ int rdtgroup_pseudo_lock_create(struct rdtgroup *rdtgrp) 


	plr->thread_done = 0;



	thread = kthread_run_on_cpu(pseudo_lock_fn, rdtgrp,

	thread = kthread_run_on_cpu(resctrl_arch_pseudo_lock_fn, rdtgrp,

				    plr->cpu, "pseudo_lock/%u");

	if (IS_ERR(thread)) {

		ret = PTR_ERR(thread);