Commit fbc06c69 authored by James Morse's avatar James Morse Committed by Borislav Petkov
Browse files

x86/resctrl: Remove rdt_cdp_peer_get() 



When CDP is enabled, rdt_cdp_peer_get() finds the alternative
CODE/DATA resource and returns the alternative domain. This is used
to determine if bitmaps overlap when there are aliased entries
in the two struct rdt_hw_resources.

Now that the ctrl_val[] used by the CODE/DATA resources is the same,
the search for an alternate resource/domain is not needed.

Replace rdt_cdp_peer_get() with resctrl_peer_type(), which returns
the alternative type. This can be passed to resctrl_arch_get_config()
with the same resource and domain.

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarJamie Iles <jamie@nuviainc.com>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Tested-by: default avatarBabu Moger <babu.moger@amd.com>
Link: https://lkml.kernel.org/r/20210728170637.25610-23-james.morse@arm.com
parent 43ac1dbf

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

+14 −85
Original line number Diff line number Diff line
@@ -1092,82 +1092,17 @@ static int rdtgroup_mode_show(struct kernfs_open_file *of, 
	return 0;

}



/**

 * rdt_cdp_peer_get - Retrieve CDP peer if it exists

 * @r: RDT resource to which RDT domain @d belongs

 * @d: Cache instance for which a CDP peer is requested

 * @r_cdp: RDT resource that shares hardware with @r (RDT resource peer)

 *         Used to return the result.

 * @d_cdp: RDT domain that shares hardware with @d (RDT domain peer)

 *         Used to return the result.

 * @peer_type: The CDP configuration type of the peer resource.

 *

 * RDT resources are managed independently and by extension the RDT domains

 * (RDT resource instances) are managed independently also. The Code and

 * Data Prioritization (CDP) RDT resources, while managed independently,

 * could refer to the same underlying hardware. For example,

 * RDT_RESOURCE_L2CODE and RDT_RESOURCE_L2DATA both refer to the L2 cache.

 *

 * When provided with an RDT resource @r and an instance of that RDT

 * resource @d rdt_cdp_peer_get() will return if there is a peer RDT

 * resource and the exact instance that shares the same hardware.

 *

 * Return: 0 if a CDP peer was found, <0 on error or if no CDP peer exists.

 *         If a CDP peer was found, @r_cdp will point to the peer RDT resource

 *         and @d_cdp will point to the peer RDT domain.

 */

static int rdt_cdp_peer_get(struct rdt_resource *r, struct rdt_domain *d,

			    struct rdt_resource **r_cdp,

			    struct rdt_domain **d_cdp,

			    enum resctrl_conf_type *peer_type)

static enum resctrl_conf_type resctrl_peer_type(enum resctrl_conf_type my_type)

{

	struct rdt_resource *_r_cdp = NULL;

	struct rdt_domain *_d_cdp = NULL;

	int ret = 0;



	switch (r->rid) {

	case RDT_RESOURCE_L3DATA:

		_r_cdp = &rdt_resources_all[RDT_RESOURCE_L3CODE].r_resctrl;

		*peer_type = CDP_CODE;

		break;

	case RDT_RESOURCE_L3CODE:

		_r_cdp =  &rdt_resources_all[RDT_RESOURCE_L3DATA].r_resctrl;

		*peer_type = CDP_DATA;

		break;

	case RDT_RESOURCE_L2DATA:

		_r_cdp =  &rdt_resources_all[RDT_RESOURCE_L2CODE].r_resctrl;

		*peer_type = CDP_CODE;

		break;

	case RDT_RESOURCE_L2CODE:

		_r_cdp =  &rdt_resources_all[RDT_RESOURCE_L2DATA].r_resctrl;

		*peer_type = CDP_DATA;

		break;

	switch (my_type) {

	case CDP_CODE:

		return CDP_DATA;

	case CDP_DATA:

		return CDP_CODE;

	default:

		ret = -ENOENT;

		goto out;

	case CDP_NONE:

		return CDP_NONE;

	}



	/*

	 * When a new CPU comes online and CDP is enabled then the new

	 * RDT domains (if any) associated with both CDP RDT resources

	 * are added in the same CPU online routine while the

	 * rdtgroup_mutex is held. It should thus not happen for one

	 * RDT domain to exist and be associated with its RDT CDP

	 * resource but there is no RDT domain associated with the

	 * peer RDT CDP resource. Hence the WARN.

	 */

	_d_cdp = rdt_find_domain(_r_cdp, d->id, NULL);

	if (WARN_ON(IS_ERR_OR_NULL(_d_cdp))) {

		_r_cdp = NULL;

		_d_cdp = NULL;

		ret = -EINVAL;

	}



out:

	*r_cdp = _r_cdp;

	*d_cdp = _d_cdp;



	return ret;

}



/**
@@ -1248,19 +1183,16 @@ static bool __rdtgroup_cbm_overlaps(struct rdt_resource *r, struct rdt_domain *d 
bool rdtgroup_cbm_overlaps(struct resctrl_schema *s, struct rdt_domain *d,

			   unsigned long cbm, int closid, bool exclusive)

{

	enum resctrl_conf_type peer_type;

	enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type);

	struct rdt_resource *r = s->res;

	struct rdt_resource *r_cdp;

	struct rdt_domain *d_cdp;



	if (__rdtgroup_cbm_overlaps(r, d, cbm, closid, s->conf_type,

				    exclusive))

		return true;



	if (rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp, &peer_type) < 0)

	if (!resctrl_arch_get_cdp_enabled(r->rid))

		return false;



	return  __rdtgroup_cbm_overlaps(r_cdp, d_cdp, cbm, closid, peer_type, exclusive);

	return  __rdtgroup_cbm_overlaps(r, d, cbm, closid, peer_type, exclusive);

}



/**
@@ -2756,11 +2688,9 @@ static u32 cbm_ensure_valid(u32 _val, struct rdt_resource *r) 
static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s,

				 u32 closid)

{

	enum resctrl_conf_type peer_type = resctrl_peer_type(s->conf_type);

	enum resctrl_conf_type t = s->conf_type;

	struct rdt_resource *r_cdp = NULL;

	struct resctrl_staged_config *cfg;

	enum resctrl_conf_type peer_type;

	struct rdt_domain *d_cdp = NULL;

	struct rdt_resource *r = s->res;

	u32 used_b = 0, unused_b = 0;

	unsigned long tmp_cbm;
@@ -2768,7 +2698,6 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s, 
	u32 peer_ctl, ctrl_val;

	int i;



	rdt_cdp_peer_get(r, d, &r_cdp, &d_cdp, &peer_type);

	cfg = &d->staged_config[t];

	cfg->have_new_ctrl = false;

	cfg->new_ctrl = r->cache.shareable_bits;
@@ -2788,8 +2717,8 @@ static int __init_one_rdt_domain(struct rdt_domain *d, struct resctrl_schema *s, 
			 * usage to ensure there is no overlap

			 * with an exclusive group.

			 */

			if (d_cdp)

				resctrl_arch_get_config(r_cdp, d_cdp, i, peer_type, &peer_ctl);

			if (resctrl_arch_get_cdp_enabled(r->rid))

				resctrl_arch_get_config(r, d, i, peer_type, &peer_ctl);

			else

				peer_ctl = 0;

			resctrl_arch_get_config(r, d, i, s->conf_type, &ctrl_val);